Conceptualization of River Basin Model, Surface water ...

Conceptualization of River Basin Model,Surface water - Ground water Interaction Analysis,

and Environmental Flow Assessment2 December 2016

Strategic Basin Planning for Ganga River Basin in India

Analytical Work and TechnicalAssistance to support StrategicBasin Planning for Ganga RiverBasin in IndiaConceptualization of River Basin Model,Surface water Ground water Interaction Analysis, andEnvironmental Flow Assessment

1220123-000

© Deltares, 2016

Marnix van der Vat, Arthur Lutz, Mark Hegnauer, Pascal Boderie ,Frans Roelofsen, Fernando Magdaleno Mas, Victor Langenbergand Kees Bons (editor) with contributions from all team members

1220123-000-VEB-0015, Version 2, 2 December 2016

Conceptualization of River Basin Model, Surface water – Ground water Interaction Analysis, and Environmental Flow Assessment

i

KeywordsIndia, Ganga River, water quality, ecology, water resources, hydrology, geohydrology,information system, GIS, water demand, irrigation, environmental flows, collaborativemodeling

SummaryPart A of this report describes the conceptualization and set-up of the River Basin Model forStrategic Planning of the Ganga Basin. It elaborates further on the information provided in theTerms of Reference, the proposal and the inception report. Moreover, this report is informedby the first results of the stakeholder involvement process and the data collection efforts. Theconceptualization of the model is not expected to be further modified. However, the set-up ofthe River Basin Model as described here, will serve as a starting point for the collaborativemodeling phase. During this phase, the model set-up will be fine-tuned to meet therequirements of the stakeholders and to incorporate their knowledge and understanding ofthe functioning of the system.

Part B describes in how the surface water (SW) and groundwater (GW) relate and gives anexample of the interaction in the Ganga basin. Furthermore it describes the setup of the SW-GW assessment that will be carried out

Part C describes how a multi-scale environmental flow assessment will be developed alongthe Ganga River course, applying a consultative process based on sound scientific analyses.To allow informed decision-making on the sustainable use of the Ganga River system, it isimportant to know the consequences any changes in use may have on the ecohydrologicalfunctioning of the Ganga river system and the types of ecosystem services (ESS) this systemoffers to society. Our approach consists of four steps:

a) Review of earlier and on-going environmental flows work and partnerships for theGanga River.b) Basin-wide assessment of hydrological alteration of the Ganga River system.c) Identification of flow-ecology-ESS relationships based on expert judgment.d) Incorporation of information on key relationships collected into modeling frameworkand dashboard.

This report (together with the progress report) contributes to Project Milestone 3 andcombines the following deliverables as described in the Inception report into one report:Deliverable 5 Report describing model conceptualization and setup, and Deliverable 6 Reportwith detailed approach for Task 2: Surface-groundwater Interaction Analyses and for Task 3:Environmental Flow Assessments.

StateFinal

ii

1220123-000-VEB-0015, Version 2, 2 December 2016t

Strategic Basin Planning for Ganga River Basin in India Project


Conceptualization of River Basin Model, Surface water – Ground water Interaction Analysis, and Environmental Flow Assessment

iii

Contents

Introduction 11

A - RIVER BASIN MODEL CONCEPTUALIZATION 3

Context: The collaborative modeling process 32

Components of the River Basin Model and their interaction 83

Hydrological models SPHY and Wflow 1144.1 Spatially distributed hydrological modeling 114.2 Mountain hydrology with SPHY 13

4.2.1 Concepts 134.2.2 Set-up and link with WFlow 144.2.3 Data requirements 154.2.4 Calibration and results 15

4.3 Basin hydrology with WFlow 184.3.1 Concepts 184.3.2 Set-up and link with RIBASIM 234.3.3 Data requirements 264.3.4 Calibration and results 27

Groundwater flow modeling 2855.1 Concepts in MODFLOW 285.2 Set-up 295.3 Initial model results 295.4 Links with WFlow and RIBASIM 305.5 Calibration process 325.6 Data requirements 34

Water resources model RIBASIM 3666.1 Concepts 366.2 Set-up and link with DWAQ and ecological knowledge rules 366.3 Data requirements 376.4 Calibration 38

Pollution Load and Water Quality modeling 3977.1 Concepts 397.2 Set-up 417.3 Data requirements 437.4 Calibration 43

Application of the integrated model 448

iv



B - SURFACE WATER GROUNDWATER INTERACTION ANALYSIS 46

Approach to the assessment of the surface-groundwater interaction in the Ganga9Basin 469.1 Principles of surface-groundwater interaction 469.2 Surface-groundwater interaction in the Ganga Basin 489.3 Set up of SW-GW assessment 519.4 3D ground water management units 539.5 Ground water information GIS 54

C - ENVIRONMENTAL FLOW ASSESSMENT 56

Framing river Ganga health objectives 5610

Description of environmental flow assessment 601111.1 Principles of environmental flows, ecology and ecosystem services 6011.2 Flow alteration in the Ganga Basin 6311.3 Impact of flow alteration on ecology and ecosystem services in the Ganga Basin 64

Approach to environmental flow assessment 671212.1 Review of earlier and on-going environmental flows work and partnerships for the

Ganga River 6712.2 Basin-wide assessment of hydrological alteration of the Ganga River system 6912.3 Identification of flow-ecology-ESS relationships based on expert judgment 7012.4 Incorporation of information collected into modeling framework and dashboard 71

Data requirements 7313

References 7414

Annex 1 Data requirements 78Data collection with CWC 78Data collection with states 83Data collection with CPCB 85


Conceptualization of River Basin Model, Surface water – Ground water Interaction Analysis,and Environmental Flow Assessment

1

Introduction1

The Ganges is the most populated river basin in the world and is home to half the populationof India including two-thirds of the nation’s poor people. The basin provides over one-third ofthe available surface water in India and is the focus of over half the national water use – 90percent of this being in irrigation.

The ecological health of the Ganga River and some if its tributaries has deterioratedsignificantly as a result of high pollution loads (from point and non-point sources), high levelsof water abstraction for consumptive use (mostly for irrigation but also for municipal andindustrial uses), and other flow regime and river modifications caused by water resourcesinfrastructure (dams and barrages for diverting and regulating the river and generatinghydropower).

The Government of India has committed to an ambitious goal of rejuvenating the Ganga andis committing significant funds to address the problem. However, in addition to the technicalcomplexity and scale, Ganga rejuvenation is an inherently “wicked problem” given the widediversity of stakeholder values and perspectives and the political and institutional dimensionsthat come from distributed responsibilities across multiple jurisdictions and institutions.

The World Bank has assigned Deltares and its partners AECOM India and FutureWater tocarry out the project ”Analytical Work and Technical Assistance to support Strategic BasinPlanning for Ganga River Basin in India”.

As outlined in the Terms of Reference and our proposal, the key objectives of the project are:(i) Significantly strengthen the capability of relevant central and state government

agencies to undertake comprehensive evidence-based strategic basin planning forthe Ganga River basin

(ii) Develop, document and disseminate (through detailed analytical work andstakeholder engagement) a set of plausible scenarios that balance significantlyimproving the health of the river and maintaining an acceptable level of economicproductivity;

(iii) Build stronger and more accessible information and knowledge base to guide on-going dialogue around and management of the Ganga River basin; and

(iv) Establish on-going multi-stakeholder engagement processes in the basin to supportstrategic basin planning.

These objectives will be achieved by:(i) Developing a detailed and robust water resources planning model for the entire

Ganga basin in India and training central and state government engineers andplanners in its use;

(ii) Characterizing and analyzing surface-groundwater interactions across the basin usingthis information to refine the river modeling;

(iii) Undertaking a multi-scale environmental flow assessment across the basin and usingthese assessments to inform the scenario modeling;

(iv) Developing, modeling and disseminating a series of plausible scenarios that explorealternative options for improving water management including improving river health;

2



(v) Establishing and facilitating a multi-stakeholder consultation process (inside andoutside of government) to guide and share the work above; and

(vi) Ensuring wide access to the models and analyses and quality documentation ofthese.

This report describes the conceptualization and set-up of the River Basin Model for StrategicPlanning of the Ganga Basin. It elaborates further on the information provided in the Terms ofReference, the proposal and the inception report. Moreover, this report is informed by the firstresults of the stakeholder involvement process and the data collection efforts. Theconceptualization of the model is not expected to be further modified. However, the set-up ofthe River Basin Model as described here, will serve as a starting point for the collaborativemodeling phase. During this phase, the model set-up will be fine-tuned to meet therequirements of the stakeholders and to incorporate their knowledge and understanding ofthe functioning of the system.

The River Basin Model describes the functioning of the water system of the Ganga Basinwithin India with respect to rainfall-runoff, flow storage and diversion, water use and waterquality and ecology. The interaction between surface and groundwater is included in themodel concept, but is described in a separate report. The aim of the model is to analyses theimpact of possible future developments, such as climate change and socio-economicscenarios and the possible management strategies. The impact will be presented in the formof values for indicators, which that will be determined together with the stakeholders.

The report continues with the elaboration of how the Surface Water-Ground Water interactionis assessed in the project and a description of the Environmental Flow assessment. Theseassessments are based on and will make use of the model framework.

This report contributes to Project Milestone 3 and combines the following deliverables intoone report:

· Deliverable 5 Report describing model conceptualization and setup· Deliverable 6a Report with detailed approach for Task 2: Surface-groundwater

Interaction Analyses and· Deliverable 6b Report with detailed approach for Task 3: Environmental Flow

Assessments



3

A - RIVER BASIN MODEL CONCEPTUALIZATION

Context: The collaborative modeling process2

The collaborative modeling process commenced during the inception phase with the meetingof stakeholders at different basin-wide and state-level meetings and workshops (see also theinception report). At these meetings the stakeholder responses to the project and its set-upwere solicited, also in addition to their initial ideas on the most important water-related issuesconfronting the basin.

These initial ideas were subsequently complemented with information received fromquestionnaires that were sent to a wide range of state-level stakeholder organizations.Several questions in this questionnaire related to the perceived issues, their impacts and theircauses.

Based on the input received through the meetings, workshops and questionnaires, the projectteam identified issues that play a role in the different states. A 1-day basin-wide workshopwith key stakeholders from both the central level as well as each of the 11 Ganga states isplanned in July to provide all participants feedback on this period and insight in otherstakeholder’s responses. This meeting will be used to further validate basin-wide issues withthe addition of state perspectives; thereby integrating an even larger number of perspectivesinto the basin-wide assessment and laying the foundations for later inter-state cooperationregarding the shared use of the basin’s water resources. A particular focus of this workshopwill also be to define the initial set of indicators to be used by decision makers in the basin forwater resources planning. The final set of indicators will be finalized over the remainder of theproject and will feature in the dashboard to be developed during later stages of the project.

To validate and further elaborate these findings for input into the technical modeling process,another series of workshops will be organized in the period July-October 2016:

A. A 1-day basin-wide workshop with specialists from central level agencies. This will beused to validate basin-level issues and their causes, and to further develop and reachagreement regarding the ensuing modeling process. Involving technical specialistsfrom relevant central level agencies will provide a solid opportunity to consider themore technical issues in an integrated manner, share stakeholder perspectives, buildinter-agency cooperation, and generate interest in the modeling activities to come.

B. A series of 2-days workshop in each of the 11 Ganga states with relevant state levelstakeholders. These will be used to validate water-related issues at the state levelwith their causes, impacts, possible mitigation measures and indicators. In doing so,participants will gain an integrated shared understanding of each state’s waterresources system in addition to an appreciation of the priorities and perspectives ofthe different stakeholders. The causal chains will then be translated as much aspossible to maps as the first step in the schematization of the different models. Thisseries of workshops will contain the following elements:

4



1. Issues validation: Theissues identified during theprevious meetings and thequestionnaires will bediscussed with theparticipants, giving themthe opportunity tocollectively prioritize theseand add and/or subtractadditional issues ormeasures to this list. Post-itstickers will be used to inthis exercise as per theexample illustrated in thefigure on the right.

2. Identify the causal chains:The agreed set of issuesfrom the previous step willthen be discussed ingreater detail, to identify those that can be connected to each other in causalrelationships. Both the root causes and impacts for each issue will be identifiedand their qualitative relationships established. In addition, any potential measuresthat have been identified will be assessed according to their influence on boththeir targeted and interrelated factors. Potential indicators to measure theseimpacts will also be discussed and defined for later use in the dashboard. It isanticipated that during the process of linking the different factors together incausal chains, additional new factors (causes of causes, impacts of impacts) willmost likely be identified. An example of a possible result is given in the picturebelow:

Figure 2-1: Issues on stickers for group discussion

Figure 2-2: Causal chains emerging from group sessions



5

3. Translation of the causal chains to features on the map. The causal chains willthen be analyzed for any physical features, or any issues that can be assigned toparticular locations. These will then be drawn onto maps, which will result in apreliminary schematization of the physical system that can be used to improve theschematization for the different models. An example of how such a map mightlook is given in the picture below.

In the wake of these workshops, the modeling team will use the additional informationgleaned and decisions taken to further develop the (geo-)hydrological, water resources, andwater quality and ecological models, which will then be collaboratively validated and used forthe assessment of impacts of packages of measures in later phases of the project.

To improve communication during the collaborative modeling workshops we use the Riverflow regime-ESS concept (Figure 2-4).

Figure 2-3: Map showing participant's inputs

6



Figure 2-4: River Ganga Flow regimes- Ecosystem Services concept

The flow regime-ESS concept is an ecosystem-based and dynamic approach which fits thedynamic, non-linear nature of social/ecological systems and has proven to be beneficial inimproving the processes by offering an easier ‘language’ to communicate stakeholder’spositions and interests. The concept calls for the joint development of system understandingof the functional inter-relationships between the Ganga River and social system, the basis forriver basin management.

For an effective application of the Collaborative Modeling approach, a content-relatedanalytical framework and an adapted participatory process of involving stakeholders areessential. Whereas a common understanding of the value of the goods and services that thehealthy Ganga river basin ecosystem can provide, and the diminution of these values by ouractions, is the key to a better approach to Ganga river basin management.

The collaborative modeling seeks to:• Discover common interests in the state and health of the land-water system of

the River Ganga.• Disclose expertise and current understanding of the flow regime and important

ESS.• Help to classify and narrow down on most important ESS• Establish relationships between flow regime changes and key ESS.• Identify important region in the Ganga zonation where a given ESS is

expected to be most emphasized or realized along a river continuum.

During the workshops, the following set of questions will be discussed to gain knowledgeabout the flow-ecology-ESS interactions along the river system:

1. Where are the principal locations / tributaries for most important goods and benefits ofthe River Ganga?

a. Can you shortlist very important goods and benefits?b. Can you establish links with the current status at locations / tributaries?

2. What are the requirements for these goods and services in terms of a certain riverdischarge?



7

3. What are the requirements for certain goods and services in terms of water quality?4. Are there any specific sites to be targeted for species protection (e.g. dolphin or reptile

habitats)?5. Are there any key locations where floodplains, wetlands or whole tributaries have

altered or disappeared?6. Are there any key locations where goods and services losses are evident?

a. Are the main causes for losses known or can reasons be derived?7. Where are the key locations where environmental pollution is evident?

a. What characterizes the remaining flora and fauna?b. Can trends be established?

8. Where are the key locations where water is heavily polluted (e.g. with toxic chemicals,organic wastes, nutrients?

9. Are there any existing plans to supply water or improve its quality (e.g. by buildingSTPs) for goods and services in the future?

a. Where?b. When?c. How much water?d. What WQ measures are to be taken?

8



Components of the River Basin Model and their interaction3

The River Basin Model consists of several components that interact with each other (Figure3-1). The model as described in part A of this report deals with:

· The hydrology (Chapter 4);· The groundwater model (Chapter 5);· The water resources (Chapter 6);· The water quality (Chapter 7);

The application of the integrated modeling framework is described (Chapter 8) as well as theassessment of impacts on ecology and ecosystem services and the determination ofenvironmental flow regimes that make use of the models (Chapters 10-12).

A separate report is prepared on the storage of model input and output in the GangaWIS(Water Information System) and the presentation of results on a dashboard.

Figure 3-1 Components of the River Basin Model and their interaction

The description of the hydrology and the rainfall-runoff process has been divided over twodifferent models: SPHY and WFlow. They are both fully distributed models working on a gridof square cells. SPHY is used to describe the hydrological process in the mountainous areasin the Himalaya. This model has been selected, because it is specifically designed for glacierand snow hydrology and because it has been previously applied successfully for theHimalayas. Section 4.2 provides a detailed description of the concepts, set-up, datarequirements and calibration of the SPHY model.

The rainfall-runoff processes for the non-mountainous part of the Ganga Basin are describedby the WFlow model. This is a general purpose hydrological model that also allowscalculation of water levels and contains a simplified module to describe flooding in the floodplains of the river. The river discharges calculated by the SPHY model for the Himalayas areused as upstream boundaries for the WFlow model. The information on discharges and waterlevels calculated by WFlow are used by the groundwater model to describe the interaction



9

between surface and groundwater. This information can be used again as input for a next runof WFlow. In this way an iteration process is created to ensure consistent results from bothmodels (see further the report on the detailed approach for surface – groundwaterinteraction). The application of the WFlow model is described in section 4.3.

The water resources model RIBASIM describes the management and use of water. Itshydrological input is derived from the river discharges calculated by WFlow. RIBASIM uses aschematization of links and nodes to describe the flow of water in the rivers, the storage inreservoirs, the diversion into canals and the use and return flow by different functions. Watercan be used from rivers and canals or from groundwater. Conjunctive use of surface andgroundwater is also possible. Furthermore, return flows can be divided over rivers, canals andgroundwater. This an important aspect for the description of the water system in the plains ofthe Ganga Basin, where extensive leakage from irrigation canals, feeds the groundwateraquifers, that are themselves used for irrigation water supply. Therefore, the RIBASIM modelis also linked to the groundwater model by prescribing extraction and infiltration rates. Theconcept, set-up and data requirements of the RIBASIM model are described in Chapter 4together with a description of the joint calibration of WFlow and RIBASIM.

Water quality can be assessed from the results of the RIBASIM model by tracing the origin ofwater to different sources of pollution. This allows for a risk assessment of water qualityproblems. For the most important pollutants for which enough data become available, theRIBASIM results will be combined with a pollutant load estimation to model the water qualitywith DWAQ. The DWAQ model is described in Chapter 6.

The impact on the ecology and ecosystem services of the results of the models presentedabove with respect to discharges, water levels and water quality will be evaluated usingknowledge rules. These rules are site specific and will be developed during the projecttogether with the stakeholders. A further description of this component can be found in thereport detailing the approach for the environmental flow assessment. A description of the linkswith the other models is provided in Chapter 6.

All model input and all relevant output will be stored in the GangaWIS. The exchange ofinformation between the components of the River Basin Model will also take place throughthe GangaWIS. The management of different versions of model input and output, to representdifferent scenarios and strategies, will be included in the GangaWIS. Furthermore, the modelresults stored in the GangaWIS will provide the input for the presentation of results in thedashboard. A separate report will be prepared describing the design of GangaWIS.

Most of the components of the River Basin Model are open source. This applies to SPHY,WFlow, iMOD, MODFLOW and DWAQ. This means that both the source code and theexecutable form of the software is publicly available on internet to all interested parties andcan be downloaded free of charge. The RIBASIM software is licensed software undertransition to become open source. Deltares as the owner of RIBASIM has agreed to make thesoftware available in an executable form free of charge for application with India during andafter execution of this project. The GangaWIS and the evaluator for the knowledge rules arebuilt entirely with open source components. Any new code prepared for this whole systemduring this project will be made available to all interested parties free of charge.

The project area is defined in the terms of reference to “encompass the entire Ganga Riverbasin in India including all tributaries upstream of Farakka Barrage on the Ganga River”.Furthermore it is stated that “the modeling will need to ensure robust assessment of the flows

10



that enter the Ganga via the Nepalese tributaries”. Therefore, the combined application of thehydrological models SPHY and WFlow will cover the entire Ganga Basin upstream of FarakkaBarrage including the parts of the upstream basin located in Nepal and China. This allows forthe requested robust assessment of the upstream flows. The application of the other modelswill be mostly limited to the Indian part of the Ganga Basin upstream of Farakka Barrage, withthe possible exception of the major reservoirs on the Nepalese tributaries that might have tobe included in RIBASIM to describe consistently their operation.

The initial set-up of the models SPHY and WFlow (and also iMOD/MODFLOW) is on a cellsize of 1x1km. During project execution, the grid size might be enlarged to reducecomputation times, but only if this does not compromise unacceptably the accuracy of theresults. The models RIBASIM and DWAQ work on a schematization of the river basin as linksand nodes. A preliminary set-up of these is presented in this report, but this schematizationwill be further fine-tuned during the collaborative modeling together with the stakeholders.

The models will be applied for different periods. For calibration this depends on the length ofthe time series available for model input and for comparison of model results withmeasurements. For the discharges used to calibrate SPHY, WFlow and RIBASIM (withinIndia) it is foreseen that this period will cover 30 years from 1985 to 2015. For the waterquality the period foreseen is 2001 to 2015. The time step of the calculations in SPHY andWFlow will be one day and for RIBASIM and DWAQ one month. The reason for this is thatthe main hydrological processes take place within periods of days and require calibration onthis temporal resolution. The main processes regarding water resources and water quality, onthe other hand, can be dealt with on the larger time scale of a month.

The aim of the River Basin Model is to support strategic planning on a basin level. Therefore,it is very important to keep the temporal and spatial schematization relatively simple and notto try to include a high level of local detail, because this does not support strategic levelplanning and might even present results with a false sense of accuracy. This requires trade-offs to be made during the collaborative modeling process between the amount of detail to beincluded in the models and the strategic purpose for which they will be applied.



11

Hydrological models SPHY and Wflow4

4.1 Spatially distributed hydrological modelingThe hydrological properties and future hydrological changes of single catchments or entireriver basins are typically assessed with hydrological models. Hydrological models aresimplified representations of components of the hydrological cycle, as shown in Figure 4-1.

Figure 4-1. Overview of the relation between the real world situation and the (conceptual) hydrological model.

Many hydrological models are used and depending on the model’s purpose they are basedon different concepts and level of detail included. The simpler hydrological models areempirical models. These models are largely based on observed relationships rather thanbased on simulated physical processes. Usually they are based on the relationship betweenprecipitation and discharge. These models are often lumped, treating a complete watershedas a homogeneous whole. On the other side are the more complex, physically-based models.These models have detailed, descriptions of physical processes, and often need a largenumber of input variables. They can include energy-balance modeling besides water balancemodeling. Physically-based models are often distributed, dividing a watershed intoelementary units like grid cells and calculating flows between them. There is a large transitionzone between the empirical and physically-based models in terms of the detail ofrepresentation of physical processes. Models in the transition zone are often referred to asconceptual models. Similarly there is also a transition in spatial discretization between lumpedmodels and distributed models. The models in the transition zone are often categorized assemi-distributed, dividing a watershed in different areas or sub basins. In this project, a fullydistributed modeling approach is applied, with two complementing models: SPHY for theupstream mountainous part of the Ganga basin, and WFLOW-SBM for the downstream partof the Ganga basin. The advantage of using a fully distributed approach over a lumpedmodeling approach is that the spatial variations in physical properties within the basin, asshown in the example in Figure 4-2, can be well represented, and therefore model output forevery grid cell can be used, rather than only at a basin’s outlet, as is the case for a lumpedapproach. Besides, better knowledge about the hydrology in different parts of the basin canbe obtained.

12



Figure 4-2. Example of the differences in hydrological response of the system within a river basin. This implies theimportance of taken into account the distribution of these processes in the hydrological model.

Figure 4-3. Examples of gridded data that can be used as input for the models, or that is generated by the models.

In a distributed approach the basin is divided in grid cells of equal size, and for each grid cellthe physical processes that contribute to changes in the grid cell’s water balance are



13

simulated. Besides transport of water between grid cells is calculated, thus representing theflow of water from upstream to downstream.

Also the input data (precipitation, evaporation, temperature) for the distributed hydrologicalmodels is distributed over the basin (see Figure 4-3). It is not needed to lump the rainfall overthe whole (sub)catchment. The distribution of the meteorological inputs comes much closer towhat happens in reality, therefore the distributed models represent the real world in muchmore detail.

4.2 Mountain hydrology with SPHY

4.2.1 ConceptsThe Spatial Processes in Hydrology model (SPHY) is a spatially distributed leaky bucket typeof model, and is applied on a cell-by-cell basis. The main terrestrial hydrological processesare described in a conceptual way so that changes in storages and fluxes can be assessedadequately over time and space. SPHY is written in the Python programming language usingthe PCRaster (Karssenberg et al., 2001, 2010; Schmitz et al., 2013) dynamic modelingframework.

Figure 4-4: SPHY modeling concepts. The fluxes in grey are only incorporated when the groundwater module is notused. Abbreviations are explained in the text.

SPHY is grid based and cell values represent averages over a cell. For glaciers, sub-gridvariability is taken into account: a cell can be glacier free, partially glaciered, or completelycovered by glaciers. The cell fraction not covered by glaciers consists of either land covered

14



with snow or land that is free of snow. Land that is free of snow can consist of vegetation,bare soil, or open water. The dynamic vegetation module accounts for a time-varyingfractional vegetation coverage, which affects processes such as interception, effectiveprecipitation, and potential evapotranspiration. Figure 4-4 provides a schematic overview ofthe SPHY modeling concepts.

The SPHY model provides output variables that can be selected based on the preference ofthe user. Spatial output can be presented as maps of all the available hydrological processes,i.e., actual evapotranspiration, runoff generation (separated by its components), andgroundwater recharge. These maps can be generated on a daily basis, but can also beaggregated at monthly or annual time periods. Time series can be generated for each cell inthe study area. Time series often used are stream flow, actual evapotranspiration andrecharge to the groundwater. For more detailed description of the concepts of modeling highmountain hydrology in SPHY, please refer to the inception report, the theoretical manual(Terink et al., 2015b) , and journal paper (Terink et al., 2015a).

4.2.2 Set-up and link with WFlowThe SPHY-model is set up for the upstream, mountainous part of the Ganga basin. Thisdomain covers large parts of Himachal Pradesh and Uttarakhand in India, large part of Nepaland parts of China on the Tibetan Plateau. The model extent, which is derived from thehydrologically corrected HydroSheds SRTM DEM (Lehner et al., 2006) is indicated in themodel’s projection in Figure 4-5. The discharge generated in the SPHY model domainculminates at the model’s nine outflow locations (Figure 4-5). The simulated discharges atthese locations feed into the WFLOW model, which is set up for the downstream parts of theGanga basin.

Figure 4-5: SPHY model extent (green rectangle), outflow locations (green dots), and their catchments.



15

Table 4-1: Properties of SPHY model upstream Ganga.Projection Asia South Lambert Conformal Conic

(EPSG:102030)

Spatial resolution 1x1 km

Simulated grid cells 260531

Time step 1 day

Most important model inputs are a digital elevation model (DEM), meteorological forcing,glacier extents, soil properties and land use types. Initial model setup is done with dataavailable in the public domain, and can be refined with local data where available.

4.2.3 Data requirementsSPHY needs static input maps as well as series of input maps for meteorological forcing. Asstatic input SPHY needs a digital elevation model (DEM) and a local drain direction map andslope map which can be derived from the DEM. Furthermore it needs a land cover map withassociated evapotranspiration coefficients assigned to each land cover type, soil map withquantitative soil properties for the topsoil and subsoil, map of glacier outlines and distinctionin debris-covered and debris-free glacier surfaces. As map series input it needs daily grids ofprecipitation (mm/day), and daily mean air temperature, daily maximum air temperature anddaily minimum air temperature (all in ˚C). Detailed information on the input data is provided inAnnex 1.

4.2.4 Calibration and resultsThe calibration strategy for SPHY is based on calibration of simulated discharge to observeddischarge. Calibration is done for monthly averaged discharges and focus of the analysis ofcalibration results is on monthly and annual discharge totals. The model performance isquantified by the Nash-Sutcliffe efficiency (NSE, (Nash and Sutcliffe, 1970)), Pearson’scorrelation coefficient (or R2), and bias (or relative volume error (RVE)). A ten year period isused for model calibration, whereas a period of 5 (different) years is used for an independentvalidation of the model’s performance. Obviously, the locations used for calibration andvalidation are largely determined by data availability. Ideally, the locations used for calibrationand validation represent a large range of catchment types in terms of catchment area,hypsometry, degree of glaciation, climatic regime, soil and land use type.

At least for five gauging stations in Nepal, daily data is available for 1998-2007. This data isproperty of the Nepal Department of Hydrology and Meteorology (DHM) and can be used formodel calibration and validation, but cannot be published. The locations of these stations areindicated in Figure 4-5 with green dots. The station locations from CWC in the upstream partof the Ganga basin are indicated in the same figure with red dots. The most useful of thesestations seem to be the stations with ID’s 18, 20, 14, 12 and 9, but their data availability is notyet known. These stations are located near the outlets of the upstream model domain and/orjust above a major dam.

16



Figure 4-6: Maps of some model inputs at model resolution. Top: digital elevation model, middle: glacier outlines,bottom: land cover types.



17

Figure 4-7: Possible gauging station locations identified for model calibration. Station properties are listed in Table4-2 .

Table 4-2: Locations of gauging stations identified in the upstream Ganga basin. ID’s are indicated in Figure 4-7.ID StatName StatCode River Lat Lon1 Badrinath GG2OOV5 Ganga/Alaknanda 30.771 79.4942 Bausan GYOOOZ3 Yamuna 30.516 77.9283 Chandrapuri GG25O15 Ganga/Alaknanda/Mandakini 30.438 79.0734 Deoprayag(a1) GG1OOA1 Ganga/Bhagirathi 30.150 78.5985 Dharchula Ganga/Mahakali 29.846 80.5436 Haripur GYXOOD4 Yamuna/Tons 30.526 77.8527 Jateon Barrage GYWOOK6 Ganga/Yamuna/Giri 30.589 77.4848 Jauljibi GGU64D1 Ganga/Ghaghra/Sharda/Gauriganga 29.750 80.3679 Jhulaghat Ganga/Mahakali 29.571 80.38310 Joshimath GG2OOS3 Ganga/Alaknanda 30.565 79.56111 Karanprayag GG2OOK2 Ganga/Pinder 30.256 79.22112 Nandkeshi GG26OJ4 Ganga/Alaknanda/Pinder 30.083 79.50813 Naugaon GYOOOZ8 Ganga/Yamuna 30.792 78.13514 Rudraprayag_BC GG2OOG5 Ganga/Alaknanda 30.273 78.96115 Srinagar GG2OOD5 Ganga/Alaknanda 30.226 78.77616 Tawaghat GGU65C3 Ganga/Ghaghra/Sharda/Kali/Dhauliganga 29.933 80.58017 Tehri (Zero Point) GG11OA1 Ganga/Bhagirathi 30.357 78.48318 Tuini(P) GYX1OA1 Yamuna/Pabbar 30.960 77.85419 Tuini(T) GYXOOM4 Yamuna/Tons 30.940 77.84720 Uttarkashi GG1OOK4 Ganga/Bhagirathi 30.739 78.35621 Yashwant Nagar GYWOOP5 Yamuna/Giri 30.887 77.206A Turkeghat 604.5 Arun River 27.33 87.18B Barhbise 610 Bhote Koshi 27.79 85.88C Pachuwarghat 630 Sunkoshi River 27.56 85.75D Khurkot 652 Sunkoshi River 27.33 86.00E Rabuwa Bazar 670 Dudhkoshi River 27.27 86.65F Mulghat 690 Tamor River 26.93 87.32G Chatara 695 Saptakoshi River 26.87 87.15

18



To aid in calibration the automated “Limited Memory Algorithm for Bound ConstrainedOptimization” (L-BFGS-B) is used (Byrd et al., 1995). This algorithm is applied to the NSE ofthe correlation between simulated and observed discharge, to find the parameter set whichresults in the maximum NSE. One calibrated parameter set will be used for the entireupstream model domain, because not all catchments have gauges and the spatial variabilityof model parameters cannot be assessed for the entire model domain. Model parameters tobe calibrated are listed in Table 4-3.

Table 4-3: SPHY model calibrated parameters.Parameter name Symbol

Degree day factor for clean ice glaciers DDFCI

Degree day factor for debris covered glaciers DDFDC

Parameter name Symbol

Degree day factor for snow DDFS

Critical temperature for precipitation to fall as snow TCrit

Water storage capacity of snow pack SnowSC

Minimum slope for gravitational snow transport Sm

Minimum snow holding depth ShdMin

Snow holding depth threshold function parameters SS1

SS2

Potential sublimation function SubPot

Base flow recession constant αGW

Routing recession coefficient kx

4.3 Basin hydrology with WFlow

4.3.1 ConceptsThe Wflow-SBM model is, like the SPHY model, a spatially distributed model and is appliedon a cell-by-cell basis. The main terrestrial hydrological processes are described in aconceptual way so that changes in storages and fluxes can be assessed adequately overtime and space. Wflow is written (just as SPHY) in the Python programming language usingthe PCRaster (Karssenberg et al., 2001, 2010; Schmitz et al., 2013) dynamic modelingframework.

Wflow is grid based and cell values represent averages over a cell. The following processesare simulated and will be explained in more detail:§ Snow module§ Rainfall interception module§ Soil module§ Kinematic wave routing module



19

Snow module

Precipitation that falls in regions that are very cold, like in high, mountainous areas, can fall assnow. How it is decided whether precipitation falls as snow or rain is calculated in the snowroutine. For this, a degree-day factor is used. This routine uses a threshold temperature (tt),below which precipitation in principle will fall as snow. Also in reality, there is no very strict linebetween precipitation falling as snow and precipitation falling as rain. There is mixed zonewhere both rain and snow can fall. This is defined in the snow routine as an interval betweenan upper and a lower temperature (ttint) in which snow and rain can fall at the same time. Thisis also represented in Figure 4-8.

Figure 4-8. Schematic overview of the snow melt routine using the degree-day factor.

Snow is stored in the model and can build up as long as the temperature is below thethreshold temperature (tt). When the temperature comes above the threshold temperature,snow starts to melt according to the degree-day factor (cfmax). This parameter controls howmuch snow can melt (in mm), per day and per degree Celcius temperature differencebetween the actual temperature and the threshold temperature. In Figure 4-9 the effect oftaking different values for the degree-day factor is shown.

Water can also refreeze when the temperature degreases. This is controlled by the CFRparameter. In the end, water that is melted and does not refreeze is transferred to the soilroutine. A complete schematic overview of the snow routine is given in Figure 4-10.

20



Figure 4-9. Effect of the degree-day factor (cfmax) controlling the snow melt for a constant temperature difference of2 degree Celcius.

Figure 4-10. Schematic overview of the snow routine.



21

Rainfall interception moduleRainfall interception is an important process in the hydrological cycle. Depending on thedensity of the canopy, more or less water can be stored. From the canopy, evaporation takesplace. This water will therefore not come to runoff. If this process is ignored, more waterenters the runoff process in the model, generating more runoff.

The rainfall interception is controlled by a set of parameters, which are mainly based on theland-use / land-cover in the basin. Dense forest stores more water than, for example, opengrass-land. By linking the parameter values to the different classes of land-use, thesedifferences are taken into account in the Wflow model. The processes important forinterception are schematically presented in Figure 4-11.

Figure 4-11. Schematic overview of the rainfall interception module.

Soil moduleThe soil module in the Wflow-SBM model is represented as a single bucket model. This isschematically represented in Figure 4-12. Within this bucket, the water table can go up anddown, depending on the sum of the in- and outflows in the bucket. The movement of thewater through the soil is controlled by a set of parameters, setting the properties of the soil.These parameters include the maximum depth of the different zones (i.e. the saturated andun-saturated zones), the porosity of the soil controlling the flow velocity through the soil (bothvertically and horizontally) and the rooting depth of the vegetation controlling the amount oftranspiration through the vegetation.

22



Water enters the soil module from the snow module, the interception module and from directrainfall. There is also linkage with the kinematic wave module. Water moves from the soilmodule to the kinematic wave module, but water can also infiltrate through the river bottomand enter the soil. This might be of special interest in the Ganga basin, where it is known thatthe groundwater table in some areas can be (far) below the river bottom.

Figure 4-12. Schematic overview of the soil module.

One of the most important parameters for calibration is the M parameter. This parametercontrols the hydraulic conductivity. Using the M parameter, non-linear decrease of thehydraulic conductivity with depth is introduced. This represent the fact that deeper soils aregenerally more compacted, resulting in lower hydraulic conductivity.

For higher values of the M parameter, the hydraulic conductivity at larger depth is higher,meaning that more interaction between the saturated and unsaturated part of the soil ispossible. It is very difficult to determine the value for M. Therefore, the value for M is normallydetermined by calibration of the model. In Figure 4-13 the relation between hydraulicconductivity and depth is shown for different values of the M parameter.



23

Figure 4-13. Relation between hydraulic conductivity (K in mm/day) and depth (z i in mm) for different values of theM parameter.

Kinematic wave module

The water in the Wflow model is routed through the river network using a kinematic waveroutine. The kinematic wave is an approximation for one-dimensional dynamic waves in theriver. The kinematic wave model solves a simple form of the shallow water equations, inwhich two terms (i.e. the inertia and the pressure-differential terms) are assumed to beinsignificant and are thus ignored. It basically comes down to solving the continuity equation,for which simple formulae like Manning or Chezy formulae can be used (Miller, 1984).Different roughness values can be set for different stretches of the river, controlling speed inwhich the water flows through the river system.

4.3.2 Set-up and link with RIBASIMFor the building of the Wflow model, the most important data source is the elevation data. Forthe project the SRTM90 dataset is used (Jarvis et al., 2008). Since the resolution of the 90meter SRTM Digital Elevation Model (DEM) is too high for using it in the model, the DEM isresampled to a 1000*1000 meter resolution for the whole Ganga basin. From the DEM, thelocal drainage direction map (LDD) is derived. This map contains the information about allpossible direction the water can flow to. From the LDD the river map is abstracted. In Figure4-14 the Ganga basin extend is shown, including the elevation data (DEM) and river networkderived from the DEM.

24



Figure 4-14. Overview of the Ganga river basin upstream from Farraka dam, with the DEM and rivers derived fromthe DEM (elevation in meters).

As described in section 4.3.1, most hydrological processes depend largely on the land use.Therefore, a map of the different land use classes is needed to distinguish the differenthydrological processes in the Ganga river basin. In Figure 4-15 an example of the ESAGlobCover map for the Ganga basin is shown. The map clearly indicates the differences inland use and land cover over de Ganga basin. This provides crucial information to build thehydrological models.

The soil properties in the Ganga basin can be derived from the Digital Soil Map of the World,as shown in Figure 4-16. The soil properties can be related to the hydrological processes andparameters. Different soil types will react different, hence different parameterization based onthe soil types will increase the realism of the model.



25

Figure 4-15. Overview of the land use classes within the Ganga river basin, based on the ESA GlobCover dataset.The land classes have been resampled from the original classes for better use in the hydrological modeling.

A first model was setup during the course, given in March 2016. This model was completelybased on the datasets found in the public domain. Some properties of the model are given inTable 4-4. The next steps of setting up the model include:

§ Refine the model based on the collected data.§ Calibrate and validate the model.§ Connect the model to the RIBASIM model (Chapter 4).§ Run the model for the selected period and (climate) scenarios.

Table 4-4: Properties of Wflow model of the complete Ganga basin upstream Farraka dam.Projection Asia South Lambert Conformal Conic (EPSG:102030)

Spatial resolution 1x1 km

Simulated grid cells 2,563,074

Time step 1 day

26



Figure 4-16. Overview of the soil type classes within the Ganga river basin, based on the Digital Soil Map of theWorld. The soil type classes have been resampled from the original classes for better use in the hydrologicalmodeling, based on their dominant soil type.

To connect the Wflow model to the RIBASIM model, the output of the Wflow model is used asinput for the RIBASIM model at selected locations. Since the Wflow model simulates thenatural flow, large infrastructural elements in the system, like dams and reservoirs, will not beincluded in the model in much detail. This is typically the domain of the RIBASIM model.Therefore, logical connection points are the inflows to large reservoirs and dams. Wflow willcalculate the (natural) inflow and RIBASIM will route this water through the systemdownstream.

4.3.3 Data requirementsWflow needs static input maps for the schematization of the model as well as series of inputmaps for meteorological forcing of the model. As static input Wflow needs a digital elevationmodel (DEM) and a river network to “train” the derivation of the local drainage direction (LDD)map. Furthermore Wflow needs land cover map soil maps, which can be linked to thedominant hydrological processes. Information about the phenology (i.e. the temporal changeof the canopy thickness) is mandatory, but can increase the quality of the model.

As map series input Wflow needs daily grids of precipitation (mm/day), daily mean airtemperature (in ˚C) and preferably, potential evaporation (in mm/day). Also meteorologicalstation data is required to validate the gridded datasets and, if needed, to correct the gridded



27

datasets for e.g. elevation. Most of these datasets can be obtained from the public domain. Ifmore detailed data is available locally, these data can be used to refine the Wflow model.

For the calibration and validation of the Wflow model (see next section), discharge data ishighly relevant. Ideally, the discharge data is provided with a daily frequency, since the modelwill be run with this time step. However, if daily data will not be available, monthly average (ortotal) discharges also suffice for a global optimization of the Wflow model. Detailedinformation on the input data is provided in Annex 1.

4.3.4 Calibration and resultsThe Wflow model is calibrated based on observed meteorological and dischargemeasurements. For this, the requested data must be obtained from CWC, see Annex 1. Theoverall performance of the model is analyzed based on the monthly average (or total) flow.For a check on the total volume of water, also annual total discharge will be checked.

The comparison of the observed and simulated discharges is done at river locations wherethe flow is mainly undisturbed. Typically, the Wflow model is calibrated on stations which arelocated upstream of (large) infrastructural changes in the river. A stepwise approach forcalibration is described below:

1) Select relevant locations with good observations for calibration:a) Based on geographical location.b) Data availability.c) Data quality.d) Period for which the data is available.

2) Do a large number of simulations with different parameter values.3) Analyze the different simulation results with observations:

a) Based on daily hydrograph comparison (if available).b) Based on mean monthly discharges (or discharge regime).c) Based on annual total volumes.

4) Calculate for each simulation the value of the performance measures, like Nash-Sutcliffeefficiency (NSE, (Nash and Sutcliffe, 1970)), Pearson’s correlation coefficient (or R2) andbias (or relative volume error (RVE)).

5) Select the parameters for which the model performs best, defined by a scored index ofthe different performance measures.

Validate the model by running the model for a different period.

28



Groundwater flow modeling5

The chapter 9 the set-up of the SW-GW assessment will be described. An importantcontribution to that assessment are the analytical results based on the River Basin Modeltool, especially the part simulation the SW-GW interaction; iMOD. This chapter describes theset-up of this groundwater flow model in relation to the River Basin Model tool.

5.1 Concepts in MODFLOWDeltares developed the iMOD software package (Vermeulen 2016) which will be used tosupport the analytical work of understanding the Ganga Basin groundwater system. iMOD isan easy to use Graphical User Interface combined with an accelerated Deltares-version ofMODFLOW (McDonald 1988) with fast, flexible and consistent sub-domain modelingtechniques. iMOD facilitates very large, high resolution MODFLOW groundwater modelingand also geo-editing of the subsurface and is very powerful in the visualization of model datafrom different sources. iMOD is open source since June 2014.

MODFLOW is the U.S. Geological Survey flow model for the simulation of flow ofgroundwater through aquifers. It is a finite-difference model and provides for differentmodules, each modeling a specific phenomenon.

Recharge moduleMODFLOW provides for several modules to calculate the groundwater system, depending onthe processes simulated. Recharge can be calculated by Modflow using modules like EVT orUZF. However, because SPHY and WFlow calculate the spatial net recharge component, thegroundwater model will use this variable as input to the ground water model through therecharge module RCH.

River moduleRivers are element that can gain or lose water, depending on the surface water level andgroundwater head. The RIV module of MODFLOW provides for this process. The resistanceto flow between the compartments groundwater and surface water is the lumped parameterConductance [m2/d]. In standard Modflow, the river line elements are gridded to the modelscale. In iMOD rivers are represented in ISG format. The ISG-file format is developed tocapture all relevant information used by surface water elements in direct relation withgroundwater. It water level, bottom level, infiltration factor, conductance/resistance, andmoreover, the actual outline of the surface water element.

Drainage moduleStreams without managed water levels, the fixed Rivers are elements that can gain or losewater, depending on the surface water level and

Well moduleFor agriculture, industry and domestic use, groundwater is pumped from shallow or deepaquifers. In Modflow the WELL module contains the point location, depth and volumepumped. The pumping rate in some cases will have a seasonal variation that can be modeledwith this module based on input from RIBASIM.



29

5.2 Set-upFor both the groundwater model and the hydrological model, the model domain is chosen thesame in order to organize a smooth model coupling. While the active domain for thegroundwater model is smaller than for the hydrological models, part of the groundwater modelis defined inactive.

For this project the “Asia_South_Lambert_Conformal_Conic” projection is used (also knownas EPSG: 102030). In that projection the window to be modeled is set to the followingcoordinates:- XY lower left: -6.087.000 / 3.599.000- XY upper right: -4.257.000/ 4.899.000- X distance: 1830 km / Y distance: 1300 km

Because the initial model cell size is 1 km x 1km the number of columns and rows isrespectively 1830 and 1300. The number of model layers depends on the hydrogeologicalcharacteristics of the subsoil. In aquifers the groundwater flow is in general horizontal whilethe flow in aquitards is vertical. The vertical extent (depth) of the model depends on the depthto where the influence of the measures and scenario’s reaches. An impermeable layer usuallyis the boundary of a model.

In a pre-processing phase of a model run, all model data as described in paragraph 0 isrescaled to the actual model cell size. During the model development, attention will be paid tothe process of rescaling river elements (lines) to a model cell of 1000x1000 meter. Processesthat are relevant at small scales might become irrelevant at larger scales.

The initial model scale is 1x1 km. In case the conclusion is that it is to coarse, iMOD can(locally) zoom in to a finer scale, for instance 500x500 m.The focus of the sw-gw analysis is on the most important Groundwater Management Units asexplained in chapter 9.3.

5.3 Initial model resultsTogether with the Faculty of Geoscience (University of Utrecht) Deltares worked on thedevelopment of a global scale water demand model PCR-GLOBWB (for more detail, seehttp://pcraster.geo.uu.nl/projects/applications/pcrglobwb). PCR-GLOBWB is a globalhydrology and water resources model. It is built to simulate global terrestrial hydrology andhuman water use at daily time step and 5 arcminute resolution (approximately 10 km at theequator).

The initial groundwater model for the Ganga basin is a cut out of the existing global PCR-GLOBWB model. During the first phases of the project, the groundwater model will bedetailed, whenever new datasets are available. Figure 5-1 shows the average piezometricheads in the first aquifer calculated with this initial model.

30



Figure 5-1: Calculated head [m] in the Ganga Basin with a test version of the Ganga groundwater model

5.4 Links with WFlow and RIBASIMThe groundwater model is loosely coupled with both WFlow and Ribasim. The definition of aloosely coupling is: two (or more) individual models are coupled via the exchange of modelresults. The output of one model forms the input of the other. This paragraph describes theinput and output on which the coupling is based.

Figure 5-2: Schematic representation of technical interaction between Ribasim, WFlow and iMOD



31

Modflow-WFlowWFlow calculates surface run off and evaporation. This provides information on the volume ofwater that recharges the groundwater. This data is input for the Modflow model. While bothModflow and WFlow are distributed models, the data exchange is on cell basis.

Modflow-RibasimRIBASIM describes the management and use of water. Water can be used from rivers andcanals or from groundwater (abstraction wells). The output of the RIBASIM model is ademand for a volume of groundwater. This output is input for Modflow as is defines theabstraction rates in the WEL module.

Not all well numbers and well locations are known. In those cases an artificial well distributionhas to be developed based on expert judgment. An example is shown in Figure 5-3.

Modflow is a distributed model while Ribasim has a lumped set-up so the data exchange isbased on ID numbers of the Ribasim groundwater reservoirs.

Modflow calculates the dynamic of the groundwater level. In case the groundwater level dropsit can get out of reach of an abstraction well. In that case it will reduce the abstraction rate,even to zero. It might be necessary to use the groundwater level as input to check whetherRibasim is allowed to claim a volume of groundwater.

Another result of a Ribasim calculation is the irrigation loss to the groundwater compartment.This flux is input for the groundwater model. Ribasim also calculates the remaining flux (waterlevel) in rivers. This water level is transferred to the groundwater model as a boundarycondition. With this new boundary conditions, iMOD calculates the fluxes to (gaining) andfrom (loosing) the river system. This output is redirected to the Ribasim model and is used fora rerun of Ribasim. In this way an iteration process is created to ensure consistent resultsfrom both models.

32



Figure 5-3: Example of artificial distribution of lumped groundwater wells over the Ganga basin, one for each Talukaarea (blue: Ganga Basin).

5.5 Calibration processCalibration of the groundwater model is the process of creating a model that optimallyrepresents the geohydrological phenomena needed for the purpose given. The users musthave confidence in the model's predictions.

Two types of measurements are used for the calibration of the groundwater model:piezometric head measurements and surface water discharge measurements. The techniciMOD provides for parameter optimization of a groundwater model is a package called PSTwhich is based on an existing optimization code PEST (Doherty 2010).

The calibration process distinguishes 4 phases:- Selection and analyzing of the right measurements;- Sensitivity analysis of model parameters followed by model (concept) optimization- Final parameter calibration- Validation

Data selectionThe comparison of the observed and simulated data is done based on piezometric headmeasurements and measurements of surface water discharge.

Discharge measurements are selected at river locations where the flow is mainly undisturbed.These are typically stations which are located upstream of (large) infrastructural changes in



33

the river. The station locations will be selected in consultation with the team developingWFlow.A large number of groundwater measurements are available from the CGWB and othersources with different quality, measuring method, frequency and from specific locations (nearriver, near road, near abstraction).

To select relevant locations with reliable and useful observations for calibration the selectionwill be based on (Barthel 2016):- geographical location (e.g. measurements distributed over all relevant model domains

such as sub catchments);- data availability (preferable long and continuous time series);- data quality (check on outliers, strange drift or jumps within series);In order to collect field data about surface water groundwater interaction, special attention ispaid to piezometer locations near river gauging stations (Brownbill 2011).

The model will run with a time step of one month. This means that in a special process alldata for calibration is transformed into monthly based time series.

Sensitivity analysisSensitivity analysis provides insight in those parameters that influence the outcome of themodel most. In case the first model results and measurements differ more than accepted, thereliability of these parameters will be tested and if necessary, more / detailed values will benecessary.The conclusion from the analysis can also be that mistakes were made in compiling themodel parameter set or that an important model concept is missing. In this process ofexamining the results, a final model for calibration is defined.

CalibrationThe period 1985 to 2000 is proposed for calibration of the models and 2001 to 2015 forvalidation of the models. The calibration period includes one major El Niño SouthernOscillation (ENSO) event (1997-98) and the validation period another one (2015). ENSOevents are for India associated with relatively little precipitation in the monsoon period.

The time step of the models will be one month. Therefore, calibration and validation will useaverage monthly values. The water resources analysis will cover the whole period for whichmeteorological forcing functions can be obtained: 1901-2015 if validation shows that the dataare reliable for this whole period.

The calibration not only focusses on the groundwater model, it will be an integrated processtogether with the models WFlow and Ribasim. Figure 5-4 gives an impression of theserelations.

The DEMAND for irrigation and industrial /domestic users is calculated by Ribasim. The effectof this water demand on the surface water levels (h) in both rivers and canals is calculated byWFlow. Modflow uses new rivers stages (WFlow), the abstraction of groundwater and returnflows from irrigation (Ribasim) to calculate both the groundwater head as well as fluxes to orfrom the river and canals. These fluxes are input for WFlow and Ribasim.

34



Figure 5-4: Schematic relations between hydrological models and groundwater model

ValidationValidation is done by comparing the model results with a set of monitoring time series thatwas not part of the calibration process. That can be a small set from all monitoring locations.The other option is to select the monitoring results for a complete year. For the River BasinModel the years 2006 and 2015 are proposed for validation of the models.

5.6 Data requirementsImportant step is to understand the groundwater system in order to understand the modelresults. For the understanding of the system the following maps are necessary:- Water loss and water gain Map of the Ganges river and the distributaries (based on

existing studies)- Basin wide hydraulic head map (based on studies, models etc. incl. drawdown map)- Simple hydrogeological map (determine homogenous areas based on hydrogeological

sequences), for example developed by MacDonald (2015).Depth to brackish – saltgroundwater map (mapping the existing fresh groundwater body)

- Initial groundwater quality assessment (basin wide map and/or strategic transects)- Develop a basin wide groundwater extraction map (based on: (1) existing pumping well

locations and extraction rates, (2) irrigated land use (type, number of harvests), estimatedon evapotranspiration demand, (3) (estimated) urban groundwater extractions)

- Data on groundwater extraction rates and locations: (1) Drinking water, (2) industry, (3)agriculture

- Subsidence map or informationFor the development of the numerical groundwater model data requirements are shared withother activities like the hydrology modeling. It applies e.g. for the Digital Elevation Model, landuse, precipitation and evaporation, surface water system (river, canal, drainage) including itscharacteristics (bed level / width / depth).The specific data requirements for the groundwater model are:- Characteristics of the aquifer system (depth, hydraulic conductivity, yield);- Information on Faults (map or information about horizontal hydraulic resistivity);- Groundwater extraction: spatial distributed data on rates over time, well depth and user

group. An example is given in Table 5-1. (calibration)- Time series of hydraulic heads (a selection of available time series for calibration)



35

The process of data gathering started with the easy available data in order to develop aninitial groundwater model. During the project data requirements might be detailed both in timeand space. This approach prevents for over focusing on data gathering.

Table 5-1: Estimated water availability and water use (source: CGWB 2014).

36



Water resources model RIBASIM6

6.1 ConceptsThe water resources model RIBASIM is used to combine the information on water availabilityfrom Wflow (see Section 4.3.2) with water demands and the operation of water infrastructureto facilitate water allocation. For every time step, in this case one month, a water balance iscalculated, so that the sum of the inflows, the return flows and the decrease in storage equalthe total outflow plus the water used. The result is a time series of water supply andshortages, where the water demand cannot be met. For reservoirs, the water level iscalculated as well as the amount of hydropower generated.

The basin is schematized into nodes and links. Nodes can represent inflow and outflow ofwater as well as water infrastructure for storage and diversion and water demand. Thefollowing types of water infrastructure are included in most schematizations:

· Reservoirs (including hydropower stations);· Barrages; and· Pumping stations.

The most important water demand node types include:· Irrigation;· Public water supply for domestic and industrial use;· Run-off-the-river hydropower stations and hydropower stations connected to

reservoirs ; and· Low flow requirements to represent water requirements in rivers and canals for

navigation or environmental flows.

An important feature of RIBASIM that is very relevant for the Ganga Basin is the possibility toinclude conjunctive use of surface and groundwater. Water use for irrigation and public watersupply can be divided over sources from surface and groundwater and the return flow canalso divided.

The first step in the calculation for each time step of RIBASIM involves the calculation ofwater flow without demand. Then the water demand is fulfilled based on water availability.The operation of water infrastructure is determined by the availability of water and by thewater demand. Allocation between competing demands in times of shortage is based on auser defined prioritization of water demands.

For a complete description of the RIBASIM model and its functionality, the reader is referredto its Technical Reference Manual (Van der Krogt, 2008) and its User Manual (Van der Krogtand Boccalon, 2013, and Deltares, 2015). For this project version 7.01.15 of the RIBASIMsoftware package is used.

6.2 Set-up and link with DWAQ and ecological knowledge rulesA preliminary set-up of the RIBASIM model has been developed based on the currentlyavailable information. This consists of the information on sub-catchments from Wflow and theinformation on water resources use and management, mainly from the Ganga Basin report(CWC and NRSC, 2014). The preliminary schematization is presented in Figure 6-1.



37

Figure 6-1 Preliminary schematization of the water resources system in the RIBASIM model

The current schematization includes 77 sub-catchments, 21 reservoirs, 22 run-off-the-riverhydropower plants, 37 barrages and 39 irrigation areas. More detail will be added in thecoming months as more data become available and as stakeholders will provide input. A lotof input is still required to complete the schematization, such as:

· Location and amount of required discharge to serve sacred gats (spiritual use);· Location and amount of required discharge for environmental flows;· Location and amount of required discharge for navigation; and· Additional irrigation areas.

For each of the links, the flow of water is calculated for every time step. This information isprovided to DWAQ as the basis for the water quality calculation. Furthermore, the origin of thewater is traced. This allows to analyses (at a particular location and time) the fraction of thewater that originates from a potentially polluted source, such as return flow from domesticwater use (i.e. sewage) or from a polluting industry, such as tanneries. A higher fraction frompotentially polluting origins will be used as an indicator for a larger probability of water qualityproblems. This type of probability based water quality assessment will be sued for mostsubstances.

6.3 Data requirementsA lot of information on the water resources system is combined in the geographicalpresentation of the schematization. However, for all of the objects in the schematizationadditional information is required. Regarding the inflow of water, this information is obtainedfrom the results of the Wflow model (see Section 4.3.2).

For all major diversions the division of the flow should be known for each month of the year.For all reservoirs, the bathymetry is required, as well as data on its hydropower plant and theother water demands served by the reservoir.

38



To quantify the water demands further, the monthly flow requirements for each location fornavigation, spiritual use and environmental flows should be known. For public water supply,the demand is required as well as the source from which this demand is met, such asgroundwater or surface water.

The largest user of water is the irrigation sector. Therefore, special emphasis will be put onthe determination of the irrigation water demand. The actual monthly demand will becalculated for each time step from information on the areas planted per type of crop, croppingpattern, the monthly crop water demand, precipitation and potential evapotranspiration,irrigation efficiency, and canal leakage.

A complete description of the data requirements for the water resources modeling ispresented in Annex 1.

6.4 CalibrationThe RIBASIM model will be calibrated after successful calibration of SPHY and WFlow, whichprovide the input for the discharges. The calibration will focus on the discharges in the majorcanals and rivers downstream of water demand and water infrastructure and on the waterlevels in the reservoirs.

The calibration period is 1985 to 2015 and the time step is monthly. The operation ofreservoirs and barrages will be calibrated on the measured downstream flows in rivers andcanals and on the measured upstream reservoir level. The water demand will be calibratedon the upstream and downstream measured flows.

The flow to the Farakka Barrage as the most downstream point of the schematization willform an important parameter in the overall calibration, since here the effects of wateravailability, water demand and operation of the water infrastructure are brought together.



39

Pollution Load and Water Quality modeling7

7.1 ConceptsThe aim of the models described in this section is to estimate the amount and pathways ofpollution loads and to calculate the resulting concentrations of polluting substances in thereceiving surface waters. Conceptually pollutants behave as sketched in the figure below:Pollution loads may enter a river (sub)basin from upstream, are transported through surfacewaters, receive additional pollution from diffuse and point sources within the basin whichfurther increase the concentration of. While residing in the basin natural purification resultingin retention or decay may occur too, the outflow of pollutants to the next (sub)basin, sea orlake is the result of these processes. Management strategies to improve surface waterquality may aim at reducing the pollution load (prevention, treatment etc.) , enhance naturalpurification in the basin or increase the discharge in rivers (minimum flows).

A water quality model is the targeted tool to quantify the relationship between pollution loads,the amount of available water and transformation processes such as biochemical reactions.

Figure 7-1: Schematic of components of a water quality model

In general a water quality models simulates the concentration C (in mg/L) of one or moresubstances in surface water, as a function of space (x, y, z) and time (t). The basis for suchmodel is the so-called “advection-dispersion equation” with additional source terms torepresent pollution loads and sources and sink terms for substance dependent water qualitybiochemical reactions.

The advective transport is computed as the water flow through a cross section, multiplied bythe concentration at this section. The water flow is obtained from a “hydrological” model . Thedispersive transport component originates from variations of the stream flow velocity overtime and space which are not explicitly included in the advective transport. The additionaldispersive transport is proportional to the concentration gradient and a “dispersion”coefficient.

40



The advection dispersion equation is equipped with an extra source term representingpollution loadings or emissions (mass of pollutant per unit of time) and water qualityprocesses such as biochemical transformations:

dMass d(C×V) = = Transport + Loads ± Processesdt dt

The processes are typically dependent on the substance (e.g. Biochemical Oxygen Demandor oxygen) that is modeled. They can include for example decay processes (substance“disappears”) and transformation processes (substances react to become anothersubstances). Processes cause what is sometimes referred to as retention. There can bemultiple processes per substance and the decay and transformation rates are dependent onwater temperature. The example in Figure 7-2 shows three substances (BOD, CO2 and DO)and several processes changing their concentrations (mineralization in water, sediment,oxygen demand, sedimentation, atmospheric exchange)

Figure 7-2: Processes influencing the DO, BOD and CO2 concentrations

The loads in a water quality model are either measured or “modeled”. For example the wasteload discharged by a sewage treatment plant may be available from measurements (effluentdischarge m3/s x effluent concentration g/m3) and this load may be put directly into the waterquality model. The alternative is to estimate the waste load starting from the source ofpollution, in this example, from the number of people (EV) generating a certain amount ofwaste (EF) and the percentage of them (Fr) connected to a Sewage Treatment Plant with acertain treatment efficiency (Φ). The advantage of the latter approach is that it increasesunderstanding of the emission pathway(s), it allows defining measures (e.g. affecting Fr orΦ)) and conducting scenario (changes in population) and thus provide a direct a link to publicpolicy.

RIBASIM is equipped with a Waste Load Estimation procedure for different node types, thebasic equation (for one particular node type) that calculates the emission per time step is:



41

( ) ( )( ), , , , , , ,1i j i k j k l i l j m i mk l m

W EV EF Fr Frfé ù= × × × - ×ê ú

ë ûå å å

W = waste load or emission (g/s) per substance (j) per node (i)EV = emission variable (X)EF = emission factor (g/s/X)Fr = a fraction connected to STPΦ = the removed fraction due to treatmentl indicates individual sectorsm indicates individual treatment typesk indicates individual EV’s associated with a certain node type

The equation shows that there can be different emission variables per node type, for examplethe different crop types in an Irrigation node (indicated by index k). Optionally, an emissionvariable can be subdivided in to sectors (introduced to divide the industry related emissionvariable return flow over different industrial sectors).

Impacts on the ecology and services provided by the river system (ecosystem services) willbe included using a set of knowledge rules. These knowledge rules are site specific and willbe developed during the project. They will be built on the results of the other modelcomponents in the River Basin Model regarding discharges, water level and pollutantsconcentrations. The results of the knowledge rules will be a qualitative scoring reflecting thestate of ecology and ecosystem services.

7.2 Set-upAll links in RIBASIM are transferred to a completely mixed segment for the water qualitymodel DWAQ and for each link a concentration is calculated. The flow of pollutants throughthe network follows the flow of water. Some of the nodes are included in the DWAQsegments, because they hold a water volume and/or they carry inflows and outflows of water:

All other nodes are not explicitly part of any segment. The water quality model derives thefollowing quantities from the RIBASIM water allocation model:

· the total water volume per segment:

· the total horizontal water surface per segment:

· the average water depth per segment (= volume / hor. surface):

· the inflows to and outflows from the segments.

When no link storage node is included these properties are estimated from GIS information.

For the Ganga application emission estimates will be made for advanced irrigation (AIR)nodes, public water supply (PWS) nodes and nodes representing industry (IND). Theproposed setup for the emission factors and emission variables for waste load estimation ofthese nodes is given in the Table 7-1.

42



Table 7-1: Emission factors and emission variables for waste load estimation for advanced irrigation (AIR) nodes,public water supply (PWS) nodes and nodes representing industry (IND)

PWS IND AIREmission Variable(s) Population number Effluent flow, subdivided

over e.g.6 sectors suchas:

i. chemicalii. distilleryiii. sugariv. other foodv. pulp, papervi. textilevii. miningviii. metal

Cultivated areas for anumber of differentcrops

Emission Factor Per capita load inwaste water

Concentration in returnflow, dependent onsector

Emission in kg/ha/yearper crop

Reductions Fraction connectedto STPSTP efficiency

Fraction connected toCETP (common andCombined EffluentTreatment Plant)CETP efficiency

Natural treatmentefficiency

The actual schematization will largely follow the RIBASIM water resources schematizationwhich is under development. The spatial level to which pollution data are collected and usedmay be the district level.

The selection of substances to be modeled depends on the demands of stakeholders in thecollaborative modeling workshops and the data availability. The following substances arepotential candidates for inclusion in the water quality model or data analysis (the actual list ofsubstances modeled will be chosen from this list and will contain less substances).• Fecal coliforms, E. Coliforms and or Total Coliforms;• Biological and or Chemical oxygen demand• Dissolved oxygen• Total nitrogen and or N-components (Kjeldahl-nitrogen, nitrate and ammonium)• Total phosphorus and or P-components (particulate and organic and inorganic

phosphorus)• Total Dissolved Solids• Boron• Cadmium, Lead and Zinc and Cyanide• Pesticide

Next, information on pollutant concentrations, flow regime, groundwater levels and floodingtogether with characteristics of the water body (e.g., sheet piling, weirs) is used to arrive atindicators for ecosystem services. The indicators are based on a combination of quantitativeand qualitative information in a semi-quantitative evaluation framework based on locationspecific knowledge rules that have to be defined together with experts and stakeholders. Theassessment of ecosystem services will use the evaluation framework and will also be



43

expressed as score to indicate the status of the ecology and the service (A separate report isavailable on the Environmental Flow assessment).

7.3 Data requirementsThe following type of data is required:

1. Pollution load measurements from Central and State Pollution boards (see Annex 1)2. Data to support the Emission Load Estimation procedure (from Pollution boards

supplemented with publically available data (e.g. https://data.gov.in andwww.censusindia.gov.in). Specific information on fertilizer and crop protectionchemicals (pesticides) is required to estimate emissions from agriculture. Dataavailability is to be investigated.

3. In stream water quality data for calibration and validation of the water quality model.Specific data required for this are (included in Annex 1):

a. CWC stations measuring water quality (‘Q’)b. CPCB stations in the Ganga and Yamuna

4. Groundwater quality maps for EC, TDS, Nitrate, Arsenic, Boron and Fluoride5. Some additional river geometry characteristics (width, depth) to build a one

dimensional DWAQ model.

7.4 CalibrationA calibration and validation exercise is carried out to ascertain that the water quality model isa correct representation of the water system. This exercise is done by carrying out hind castsimulations, and compare the simulation result to field data. If necessary, some modelparameters are adjusted to obtain agreement between the simulation results and the fielddata. This is called “calibration”.

It is good practice to test the calibrated model again for a different time period, and check ifthe model with modified parameters is also able to provide a good hind cast for this differenttime period. This is called “validation”.

In practice, a calibration and validation exercise also includes very thorough checks andcorrections of all input data. For the Ganga water quality model we propose to use theparameters in the Waste Load Estimation to calibrate the model. A priori the largestuncertainties are expected in that part of the model. The measured concentrations at theCWC and CPCB measurement stations spatially distributed along the Ganges and majortributaries including Yamuna will be used to calibrate model results. We will use timelyaveraged data representing the monsoon and non-monsoon season.

44



Application of the integrated model8

The River Basin Model will be applied to a time series of meteorological input that will be aslong as possible. The length of the simulation period is important to include the historicalvariation between wet and dry years and especially the historical sequence of dry years inmulti-year dry periods, which produce the strongest impact on water resources and waterrelated welfare.

Combination of all available data resources could yield a total simulation period of 1900 to2015. However, the accuracy and reliability of the older meteorological data is doubtful andwill be tested before they will be used. The simulation time will be limited to the period forwhich reliable meteorological information can be collected.

The models described in this report will be applied together in one system. The interactionsare the following:

· Infiltration to the groundwater calculated by WFLOW provide boundary conditions foriMOD/WFLOW;

· Discharges and water levels calculated by RIBASIM provide boundary conditions foriMOD/MODFLOW to calculate the exchange between the river and the groundwater;

· Discharges and groundwater levels calculated by iMOD/MODFLOW provideboundary conditions for RIBASIM regarding the exchange between the river and thegroundwater;

· The groundwater use modeled in RIBASIM provides input for iMOD/MODFLOW; and· The groundwater levels calculated by iMOD/MODFLOW might provide limitations to

the amount of groundwater that can be used in RIBASIM.

These interactions mean that final calibration of the River Basin Model will include bothsurface and groundwater and its interactions.

Socio-economic developments have an important impact on water demand. Water demand isexpected to rise substantially in the Ganga Basin due to population growth and due to theincrease in per capita water use that is associated with increase in welfare. The increase inwater use takes place directly through the public water supply, but even more dramaticallyindirectly through the increase in irrigation water demand for agriculture. The impact ofdifferent socio-economic scenarios on water demand and water shortage will be evaluatedwith the River Basin Model by modifying the input for the RIBASIM model.

Another important factor in future water resources is climate changes. The River basin Modelcan be applied to analyses the impacts of climate change by replacing the historicmeteorological input data by time series modified to represent certain climate changesscenarios.

The locations where output will be generated and the selection of parameters to be includedin the output will be determined by the stakeholders in the collaborative modeling process.These results will be stored in the GangaWIS to be presented on the dashboard.

The GangaWIS will also take care of storing meta-data with the model results. These meta-data will include the version used for all model executables as well as for the model input.This will ensure that model results are reproducible. Furthermore, these meta-data will



45

provide the required information to identify for each result the combination of scenarios, timehorizon and selection of measures for which it is representative.

Model results can provide a false sense of accuracy due to their numeric nature. However,uncertainty is introduced in the model outcomes by uncertainty in the model input, the modelparameters and the model concepts and schematization. The uncertainty in the outcomes willbe assessed by performing a sensitivity analysis for the most important model input andmodel parameters. The uncertainty in model input and model parameters will be establishedby expert judgment. A number of model runs will be executed with different values for modelinput and parameters and the results will be analyzed to assess model uncertainty and toexpress this as a range around the value calculated as the model result.

All numerical modeling activities involve a simplification of physical processes to be able toperform model calculations. In the case of this river basin model the scale of the river basinrequires a relatively large degree of simplification, since it would be impossible to construct adetailed model within the time and budget available. An example of the simplificationsintroduced in the model schematizations is the clustering of irrigation in a limited number ofirrigation nodes and the inclusion of only the main irrigation canals.

However, detailed modeling is not required to support strategic planning at a basin levelwhich is the aim of the project. This means that the results of the model should be usedprudently. Not all relevant policy questions can be answered with this river basin model. Thetypes of questions that can be answered with this basin scale model include:

• What will be the impact of certain climate change scenarios on water scarcity, waterquality and river ecology?

• What will be the impact of socio-economic scenarios on water scarcity, water qualityand river ecology?

• What will be the impact of large scale water supply measures such as creation ofadditional reservoirs and inter basin linkages on water scarcity, water quality and riverecology?

• What will be the impact of large scale implementation of small scale water supplymeasures such as rainwater harvesting on water scarcity, water quality and riverecology?

• What will be the impact of large scale implementation of water demand measures suchas improved irrigation efficiency on water scarcity, water quality and river ecology?

• What will be the impact of maintaining certain environmental flow regimes on the majorrivers on water scarcity, water quality and river ecology?

• What will be the impact of large scale improvement and construction of sewage systemsand sewage treatment plants on water quality and river ecology?

The answers on these questions can be provided by the river basin model on a river basinscale making a distinction between different parts of the main rivers, but not for each andevery specific location within the basin.

46



B - SURFACE WATER GROUNDWATER INTERACTIONANALYSIS

Approach to the assessment of the surface-groundwater9interaction in the Ganga Basin

Groundwater is the major source for irrigation in the Ganges basin. Because the alluvialgroundwater system is closely connected with the river and canal systems, the two should beanalyzed and managed in relation to each other.This chapter describes in general how the surface water (SW) and groundwater (GW) relateand gives an example of the interaction in the Ganga basin. Furthermore it describes thesetup of the SW-GW assessment that will be carried out. The result of that assessment willbe reported separately.

Important contribution to the assessment are the analytical results that will be based on theRiver Basin Model tool, especially the part simulation the SW-GW interaction; iMOD. Adescription of the set-up of this groundwater flow model is presented in chapter 5.

9.1 Principles of surface-groundwater interactionStreams interact with ground water in different types of situations. Unless a canal iscompletely lined, or a riverbed is dry, there will always be interaction between rivers/canalsand the groundwater.

The four major examples of this interaction types are presented in Figure 9-1.Situation 1 is the situation of a continuous draining river (gaining river) whereas situation 3 isthe opposite: a continuous infiltrating river (a losing river) but with hydrological connection.The groundwater system is not static but heads will change over time due to differentstresses (precipitation, evaporation, well abstraction etc.). This can lead to the situationpresented in situation 2, a river segment periodically changing from drainage into infiltration.

Irrigation canals can be typical examples of situation 3 or even 5: the water levels areartificially higher than the heads in the underlying aquifer.

In case we have a large water body (e.g. lake) in combination with a rather high groundwaterhead gradient situation 4 can occur: the high groundwater head at the upstream part causesinflow to the water body while at the downstream area a lower groundwater level results in aninfiltration situation. Finally, situation 5 is an example of a disconnected river with continuousinfiltration.



47

Figure 9-1: Types of Surface Water – Ground Water interaction

We add one important phenomenon for the India situation. The (geo)hydrology of India isdominated by the monsoon phenomena. During the monsoon, when the water level rises,parts of the river area are flooded. The advantage of flooding from a geohydrologicalperspective is that the local aquifer recharges. This concept is presented in Figure 9-2

Figure 9-2: If stream levels rise higher (numbers 1 to 3), the floodwaters recharge ground water throughout theflooded areas.

The situations presented above can be a description of the natural state of the system.However, also human activities can force a system in another state. A good example ispresented in Figure 9-3. Under natural conditions the stream is receiving groundwater.Because of the installation of a pumping well (e.g. irrigation or industrial water supply) with ahigh pumping rate, the groundwater head near the river is lowered changing the river to alosing stream.

48



Figure 9-3: upper: ground water discharges to a stream under natural conditions. Lower: Placement of a pumpingwell can draw water from the stream to the well (source: Winter 1998).

The descriptions of the different situations mentioned above only describe flow directionsfrom and towards streams. The actual water volumes transported (fluxes) depend on the rivermaterial (riverbed conditions) and aquifer conditions.

9.2 Surface-groundwater interaction in the Ganga Basin

In general it is true that streams in mountainous terrain gain water. Streams flowing frommountainous terrain commonly flow across alluvial fans at the edges of the valleys. Moststreams in this type of setting lose water to ground water as they traverse the highlypermeable alluvial fans. The interaction of ground water and surface water in river valleys isaffected by the interchange of local and regional ground water flow systems with the rivers.Small streams receive ground water inflow primarily from local flow systems. For larger riversthat flow in alluvial valleys, the interaction of ground water and surface water usually is morespatially diverse than it is for smaller streams.



49

Figure 9-4: Cross section indicating different stresses on the (ground) water system

As described in the last paragraph, human changes in the system change the naturalsituation. In the Ganga Basin the stress on both the groundwater and the surface watersystem has increased for several decades. Figure 9-5 presents this stress as a ratio of waterused and water available. Especially the western states are indicated with a high stress.

50



Figure 9-5: State of the (ground)water system in India caused by overexploitation through agriculture, industry anddomestic use (source: Shiao Tien (2015) and http://www.indiawatertool.in/).

At this phase of the project, there is no picture yet of the natural situation of the (ground)watersystem in the Ganga Basin. The present state of the system, including the water stresses,leads to the actual surface water – groundwater interaction. A estimation of the type ofinteraction with the Ganga and Yamuna river is drawn in Figure 9-5 during the CentralWorkshop.

Figure 9-6: State of the river-groundwater interaction in the Ganga basin indicated by the participants of theWorkshop on Collaborative Modeling for Central Agencies (July 2016).

In the past, some studies estimated the actual state. One of the examples is the basin widecalculated estimation of the SW-GW interaction by IIT presented in Figure 9-7.The SW-GW interaction (fluxes to and from the streams) is one of the outcomes of agroundwater model. Besides that, the model also estimates the spatial state of thegroundwater level basin wide. Depending on the type of scenario chosen (e.g. difference inclimate, water use, and land use), the effect on the actual groundwater level can becalculated.



51

Figure 9-7: Surface Groundwater interaction situation estimated for 3 main streams for the Pre and Post Monsoonsituation (source: IIT 2014).

9.3 Set up of SW-GW assessmentAfter finishing the conceptualization phase, the focus for Task 2 will be on the SW-GWassessment. The findings will be presented in the “Report on surface groundwater analysis”(project deliverable 7). It explains the SW-GW interaction in the Ganga Basin in text,completed with figures to explain the concepts and maps are added to display the situation ona basin wide scale. This chapter is a detailed description of the approach to be taken. Theapproach consists of the following key activities, each of them getting a distinctive part in theSW-GW report.

Chapter: IntroductionKnowledge of the historical development of the water system can help to understand theactual behavior and status of the system. We will search for information in order to draw ahistorical timeline for (ground)water.

Chapter: Aggregated knowledge from existing reportsCentral and state organizations, research institutes and foreign consultants have analyzedthe groundwater situation in the Ganga Basin. This chapter describes the most importantprinciples. Sources of information are for example the reports:- Dynamic Groundwater Resource of India (as on 31st March 2011) by the Central

Groundwater Board (2014)- Groundwater resources in the Indo-Gangetic Basin: resilience to climate change and

abstraction by the British Geological Survey (2015)- Deep Wells and Prudence: Towards Pragmatic Action for Addressing Groundwater

Overexploitation in India by the World Bank (2010)- Aquifer systems of India by the CGWB (2012)Basin wide studies on the local scale SW-GW interaction with river Ganga or major tributariesare scarce.

The project is in the process of gathering the right information and data on the gw-sw system.Sometimes even local studies of the groundwater system are useful in assessing the Ganga

52



Basin. After all, local knowledge of characteristic situations might be valid for locations/zoneselsewhere in the basin but with similar characteristics.

Chapter: Presentation and description of basin wide thematic mapsMost basin wide maps that describe major groundwater properties are developed and madeavailable by the Central Groundwater Board. Thematic maps are presented and analyzed for:- Hydrogeological map of the basin.- 3D representation of the aquifer system based on fence diagrams (see Figure 9-8)- Groundwater level for pre- and post-monsoon situation (below surface level and above

msl).- Groundwater abstraction volumes for irrigation, industrial and domestic use.- Groundwater quality map (chloride, nutrients, arsenic, and fluoride).- Map indication level of exploitation of groundwater (see Figure 9-9).- Map indicating River gaining and loosing segments (constructed during the stakeholder

Workshops).

Figure 9-8: Calculated Basin wide bottom of the aquifer system based on 9 geological crosssections Uttar Pradesh



53

Figure 9-9: Categorization of assessment units in the Ganga Basin (CGWB, 2014)

Chapter: Analysis of groundwater level measurementsThe CGWB monitors the groundwater level in the Ganga Basin at more than 9.000 locations.These time series are used for calibrating and validating the groundwater model. As part ofthis assessment, the statistics of the time series are analyzed and presented, indicating thebehavior of the groundwater system.

Chapter: Interpretation of model results (iMOD)The groundwater model iMOD will provides for (calculated) maps to describe the systembehavior. Central maps are:- Pre and post monsoon ground water level.- Seasonal dynamic of the ground water level.- Water flux to and from the river system.- Groundwater demand for irrigation, domestic and industrial.- Drawdown caused by irrigation demand.

Al mentioned collected and calculated maps are made available in the project databasecalled GangaWIS (see also next paragraph). The outcome of this analysis will definitely bediscussed with representatives of the CGWB in order to develop and share commonknowledge.

9.4 3D ground water management unitsWith a length of over 2.500 km, the Ganga River is very extensive. Therefore the GW-SWassessment will focus most on the most important Groundwater Management Units (GMU).These 3D units will be defined along the basin in the following process- Important criteria for the selection are relative level of water use, connectivity to surface

water, water quality threats, likely future water demand but also geohydrologicalcharacteristics (e.g. soil type, aquifer thickness).

- The “relative level of water use” is an important criterion and describes the level ofsustainability of ground water use. The Ground Water Resources Assessment of the

54



country is being carried out by the CGWB at regular interval with the objective to identifyand prioritize the areas for ground water management interventions. (CGWB, 2014).Almost 15% of the assessed administrative units are Over-exploited. The most recentresult of this analysis is presented in Figure 9-9.The prioritization starts with these over-exploited areas.

- To take into account the geohydrological characteristics over the basin we include thetypology described by the British Geological Survey (see Figure 9-10).

- We will explore the status of the National Project on Aquifer Management (NAQUIM) anddiscuss whether findings from the project about aquifers at risk can be involved in thedefinition and prioritization of the GMU.

- The result of the process is a definition of approximately 5 typical units also representedas typical cross sections for which the assessment is described in more detail.

The definition of the GMU must be in line with the approach of the national and stateorganizations. To realize that, the approach and results are discussed on national level withthe CGWB. Interaction with the State Organizations will be via e-mail.

Figure 9-10: The main groundwater typologies of the Indo-Gangetic basin (MacDonald AM, 2015)

9.5 Ground water information GISLike other Tasks in the project, Task 2 will collect, process and create information necessaryto analyses and understand the system and be able to propose realistic measures. Theinformation will be existing information made available by Governmental organizations (e.g.CGWB) or processed data such as model input and model output. The availability of modelinput gives professionals the option to check the model set-up. The presentation of modeloutput give a common base for drawing conclusions.

In this project the central system to store, manage and present the data and documentscollected is the Ganga Water Information System (GangaWIS) described in Task 6. The



55

system will facilitate central storage of data, both static data as well as (semi) dynamic datalike time series from monitoring stations.

While several tasks share the same data (e.g. Digital Elevation Model, Land use andPrecipitation), the analysis of SW-GW interaction requires specific information that iscollected and made available in the GangaWIS. Most important datasets are:- Hydrogeology: spatial distribution of aquifers and their characteristics like thickness,

permeability and yield. (e.g. fence diagrams, borelog information)- Groundwater use: spatial distributed estimation of GW use (domestic, industrial water

supply and irrigation) reported by the CGWB.- Groundwater resources: spatial distributed estimation of GW resource calculated by the

CGWB based on annual replenishable ground water resource and groundwater use.- Groundwater dynamics: time series for more than 9000 monitoring stations all over the

basin (source: CGWB).- Groundwater dynamics: calculated time series of the groundwater level throughout the

basin (iMOD).- SW-GW interaction: spatial distributed calculated flux for loosing and gaining rivers for

monsoon and non-monsoon situation (iMOD).Polygon map describing the area of the 3D GW management units.

56



C - ENVIRONMENTAL FLOW ASSESSMENT

Framing river Ganga health objectives10

The approach to review, assess and consequently support the management of Ganga healthobjectives will adopt an Ecosystem–based approach. Seeing the complexity of theimpoverished river system and sub-catchments this approach recognizes the full array ofinteractions within an ecosystem, including humans, rather than considering single issues,species, or ecosystem services (see box) in isolation (Christensen et al., 1996, McLeod et al.,2005). As key element in the training, communication, and framing we will make use of trendsand status of the Ecosystem services (ESS).

Where possible we will express the functionality of the Ganga River in ecosystem servicestrends and status, i.e. in services that are provided by the river ecosystem. Such services willinclude central goods, such as clean drinking water or irrigation water, but also lesser-knownregulatory services, such as self-cleaning and water regulation of the river Ganga and herfloodplains. Waters needs to provide a religious and recreational function for people andprovide space for inspiration.

For the assessment of the health of selected sites and the whole basin we must be in consentthat:

1. The economic welfare and quality of life are highly dependent on natural river systemthat provides essential services. Most ecosystem services come forth from or aredepend on the natural Ganga river system:

o Self-purification, retention of nutrients and sediments in floodplains,o Unpolluted fish, shellfish and crustaceans as food,o Decentralized flood protection and climate regulation of nature-like

floodplains,o Groundwater recharge,o Leisure and Recreationo Protection of native species.

Ecosystem services are defined as services for people but even though being an anthropocentricapproach the term should be used in a sense of a sustainable use of water resources. Ecosystemservices are closely connected with numerous processes and functions within an ecosystemcharacterized and defined by environmental parameters on the one hand and the flora and fauna on theother hand. For our activities we will adopt the approach of the 2005 the United Nations MillenniumEcosystem Assessment (MEA), which describes ecosystem services as ‘the benefits that people obtainfrom ecosystems’. It classifies ecosystem services into four categories:

1. Production services: these are the benefits that ecological systems directly provide. E.g.,Food, Wood and fresh water.

2. Regulating services: these are Benefits arising from how a system regulates processes,resources and ecological systems. e.g., Carbon Sequestration, climate regulation, floodregulation, water purification.

3. Cultural services: these are non-material benefits people enjoy. E.g., Religions, Cleaning,Recreation, spiritual, Tourism.

4. Supporting services: these are necessary for the production of all other Ecosystem services.Supporting services do not yield direct benefits to humans (e.g. nutrient cycling, soil formation,primary production).



57

2. The river Ganga provides a variety of key ecosystem services. Damage to the riversystem leads to a decrease of her ability to provide these services. Accordingly,damages are caused when natural river system functioning is impaired or destroyed.

3. Where possible we will valuate the Ganga ESS there when it contributes indetermining the resilience of the river in terms of her sustainable use. Existingapproaches to describe the sustainability of river systems is an important startingpoint.

4. Uses which are not sustainable and which lead to short or long-term reduction ofservices need to be adjusted or - if this is not possible on short term - should becounterbalanced. For this, the nature and extent of deterioration are to be identifiedand evaluated.

5. Generally, it is more effective and less cost-intensive to maintain a healthy riversystem than rehabilitating degraded habitats. Numerous Ganga river sections arealready degraded; investments in the restoration there are required to restoreimportant services.

6. Many of the ecosystem services of river Ganga are based on processes and functionswhich have not been adequately assessed with relevance to humans or nature. Moreresearch is needed, including more precise statements about their value.

7. Many benefits of aquatic ecosystems, such as biodiversity, cannot be directlymonetized. Nevertheless, their protection is significantly valuable since clear positiverelationships exist between ESS and biodiversity (Harrison et al., 2014).

Several definitions and classification schemes for ecosystem services exist (Costanza et al.,1997; Boyd & Banzhaf, 2007). We drafted a first ESS framework that provides a platform formoving from a rather conceptual ESS overview towards an operational classification systemwhich explicitly links changes in the ecosystem services to changes in human welfare. Byadapting and re-orienting this definition it can be better suited to the purpose at hand, withlittle loss of functionality. The key feature of the ESS classification here is the separation ofecosystem processes and functions into intermediate and final services, with the latteryielding welfare benefits.

Following the general scheme in Figure 10-1, River Ganga natural capital stocks (theecosystem structure and processes and links to the abiotic environment) possess highbiological productivity and provide a diverse set of habitats and species, with a consequentflow of ecosystem services (the outcomes from the functioning of ecosystems) of significantvalue (benefits) to Indian society. From this valuation perspective, a combination of basicprocesses and ‘intermediate’ services provide final’ services of relevance to Indian welfare(‘benefits’). Ecosystem services benefits are the exports’ from the ecosystem sector to thehuman economic sector. The term ‘intermediate services’ should not be interpreted assignifying lesser significance but rather as a necessary signal that provides technically-correctguidance to avoid double counting when services are valued in economic terms (Fisher et al.,2009).

The outcomes from the functioning of ecosystems have been generically labeled ‘goods’which refer to a range of human welfare benefits derived from the flow of final servicesprovided. But the scope of the delivered final ecosystem services (and therefore the valuedgoods and benefits) is very wide from food to carbon storage, river bed protection, security &defence, tourism and nature watching. A first draft classification of the River Gangaecosystem services is shown in Figure 10-1,.

58



Figure 10-1:Ecosystem services classification for the Ganga River

For establishing and using the casual relationships between ESS and main hydrologicalparameters we need to recognize that the interlinkages between hydrology (as one of themain drivers), the Ganga river system, the functional processes therein and consequently therelated services are manifold and complex. Furthermore, the respective interlinkages mostlyresemble non-linear correlations. Still, generalizations will be made to help understand theunderlying casual relationships for support of the assessments and management.



59

For example:

- Lowered discharge àless floodplains and marshlands àless waste break downà sedimentation of contaminate sedimentsà decrease navigation and transportà expensive mitigation.

- Lowered discharge àdecrease area of groundwater recharge à waterscarcityàincreased effects contaminants and nutrients à lowered primaryproductionàdecrease biodiversityàless health and aesthetic benefits.

- Lowered discharge à decrease riverine biotopes à decrease habitatdifferentiation àlowered production of fish and crayfishà disappearance toppredators reptiles and mammals.

- Lowered and controlled discharge à less seasonality in hydrodynamical andbiological drivers à decreased dynamics and simplified Ganga food websà lessproduction system with more important role of lower animals, bacteria andvirusesà more vector borne diseases.

60



Description of environmental flow assessment11

11.1 Principles of environmental flows, ecology and ecosystem servicesAmelioration of a river´s flow regime is a critical step in any attempt to recover its ecologicalintegrity (Magdaleno, 2014). In many cases, flow pattern determines more than any otherphysical or environmental feature the structure and spatial-temporal functioning of the riversystem (Bunn & Arthington, 2002; Poff et al., 2006). Links between the river´s flow regimeand its overall status may be assessed by means of the mutual interactions between thehydrological and the ecological components of the system (Figure 3.1).

The scientific and technical acknowledgement of the aforementioned influence of flows on theriver´s status has been a reality during the last decades. This has driven to many differentattempts to identify those flow events most relevant for the protection of the river´s criticalecological processes. With that goal, numerous methods for the determination of minimumflows (later to be known as environmental or instream flows) were designed from the 1970s topresent (Tharme, 2003; Acreman & Dunbar, 2004; Magdaleno, 2009). Moreover, almost noneof those procedures have shown to be effective for the conservation or restoration of theriver´s values and functions.

A river´s flow regime may be understood as the aggregation of a wide set of hydrologicalevents (summer and winter low flows, winter high flows, ordinary and extraordinary floods anddroughts, etc.). The occurrence of all those events is determined by the physical,environmental and hydro-meteorological features of the river´s watershed. Complexity of flowregimes is a common feature of many basins, but it frequently reaches a maximum in drylandareas, where inter and intra-annual flow variabilities are especially high. Due to flowcomplexity, one of the first recommendations to be done for the river´s hydrologicalamelioration is to fulfill detailed analyses of its flow dynamics (natural or altered). This wouldcomprise the identification, at least, of three inter-annual types of flows: those associated towet, normal and dry years, and two intra-annual types: monthly and daily flows. From thisbasic analysis of the flow variability, it would be possible to deepen in the characteristics ofthe temporal flow dynamics, and to identify the trends which better describe the long-termfunctioning of the flow regime. A number of free and commercial software applications can beused today to develop that analysis in a simple and well-structured manner (e.g., IHA –Richter et al., 1996; ELOHA – Poff et al., 2010; IAHRIS – Martínez Santa-María & Fernández-Yuste, 2006; Fernández-Yuste et al., 2012). As one of their typical outputs, those applicationscharacterize flow patterns under different scenarios, and provide seasonal indicators whichallow interpreting the degree of deviation of simulated patterns from that considered asreference.

Once the inter and intra-annual flow patterns are characterized, definition of functional e-flowsshould comprise the identification of those flow components more directly linked to thephysical and ecological attributes of the river system (i.e., morphology, habitats, species,physico-chemical conditions, etc.) and to the river ecosystem services. This identification maybe hard to do, since many of the interactions and synergies between flow, ecomorphologyand ESS are still unknown. However, some interactions have already been studied anddescribed, partially if not completely. This is the case of the river´s morphodynamics, andsome biological groups, such as certain fishes, invertebrates, riparian stands and evenriparian birds (Arthington et al., 2006; Magdaleno, 2011).



61

Figure 11-1: Aquatic biodiversity and flow regimes. Source: Bunn and Arthington, 2002

For instance, in the specific case of fishes and invertebrates, communities are highlydependent on temporarily-varied minimum flows, especially during critical biological cycles(migration, reproduction, spawning, egg incubation and hatching, etc.). Those minimum flowscontribute to the existence of favorable ecological and physico-chemical conditions, and arethus very positive for their conservation or improvement. Similarly, temporarily-variedmaximum flows would be necessary to avoid colonization of natural habitats by alien speciesand deterioration of native communities. But also adequate ramping rates would be importantto avoid stress to aquatic organisms, along with attraction flows, during biologically criticalperiods, which enable the species´ normal behavior (in terms of local and regional migrations,physical growth or interaction with other aquatic organisms).

Regarding riparian vegetation, key hydrological events would be those which allow theconnection between the channel and its riparian areas, those responsible for the river´smorphology, and those with capacity to disperse seed and propagules and to createconditions for the early growth of seedlings and saplings. Being riparian plants one of thepreferred habitats for riparian birds, the referred events would also be essential for birdcommunities. Riparian birds may also be favored by other flows; e.g., those protecting nativefishes in the case of fish-eating bird species.

Most usually, calculation of habitats´ or species´ flow requirements is done by combining arange of methods. Among them, hydrological, habitat simulation and holistic procedures.Hydrological methods frequently offer a simple way to calculate an initial range of flows,applying some statistical algorithm to the non-altered or reference temporal flow series.Habitat simulation offers the alternative of modeling convenient ranges of flows by devisinghow different water levels or discharges would allow the existence of the necessary amountand quality of river habitats for target habitats or species. Holistic methodologies incorporatehydrological and habitat modeling to a broader scenario where other ecological,geomorphological or even social-based water demands are also considered.

62



Nonetheless, many of the aforementioned procedures were initially designed to just supplyminimum environmental flows in rivers, and do not adequately describe which flows should bereintroduced in the system to actually achieve its ecosystem-based goals. In other words, it isof major importance to use procedures which have a solid ecohydrological foundation(Stewardson & Gippel, 2003; Richter, 2010; Poff et al., 2010).

With that aim, different works explore regionally the specific water requirements of differentfloral and faunal species. In order to translate water needs to water management, it isnecessary to determine the main features of those critical flow events (magnitude, frequency,duration, seasonality and rate of change). And then, to integer them to implement a“functional” e-flow regime, which could also include additional recommendations, in terms ofsediment regime, water quality, etc.

This regime should harmonize river conservation with water uses, and be feasible for waterplanners and managers; otherwise, its perdurability will be difficultly achieved. At the sametime, the improvement or restoration of the flow regime should be preferably structured on thebasis of an appropriate inter and intra-annual variability, offering the necessary flexibility towater managers, in order to face natural or human-based irregularities in water offer anddemand.

The consecution of the social and environmental objectives of the improved flow regime mustfocus on avoiding intense and prolonged water stresses to the river´s habitats and species.The improved flow pattern must be committed in a significant percentage of the year, in orderto avoid damages to the fluvial landscape dynamics (Magdaleno, 2014) (Figure 11-2).

Figure 11-2.- Biocomplexity and fluvial landscape dynamics on river floodplains. Source: Poole, 2002



63

11.2 Flow alteration in the Ganga BasinFlow alteration may be defined as any changes in the main attributes of the natural river flowpattern. Natural flow regimes may be modified by different human activities and climatechange. Different procedures, such as the indicators of hydrologic alteration (for instance,shifts in seasonality of floods and droughts), help evaluate the average degree of alterationproduced in the study period. Those indicators frequently cover the whole range of hydrologicscales (habitual values, floods and droughts), components (magnitude, duration, variabilityand seasonality) and periodicity (annual and monthly) and detect the most commonalterations associated with different water uses.

In the Gangetic Plains, flow regimes are characterized by(i) significant inter-annual variability, with large differences between wet and dry

years,(ii) a substantial seasonal (intra-annual) variability, which includes intense and long

dry periods, and(iii) frequent extreme flooding. Based on these attributes, the flow regime controls the

composition, structure and dynamics of the river ecosystem. Importantly,permanent changes in the flow regime result in significant morphologicalalterations. These alterations are linked to shifts in sedimentary dynamics and tochanges in the composition, distribution and succession of riparian vegetationbecause these factors play a key role in the river planform and cross-sectionshape (Gran & Paola, 2001; Hupp & Osterkamp, 1996).

Flow alterations, which are not occasional or temporal, result in:(i) a drastic reduction in flow downstream from the dam (when the water comes from

that dam) or(ii) an intense modification in the seasonal regime (intra-annual variability), when the

channel itself is used to convey the water used for irrigation.

In the Ganga basin, pressures due to increased population and economic development arebehind the alteration of the river´s flow regime. Changes are mostly linked to increased riverregulation (by means of dams and other barriers), or modification of flow dynamics by levees,urbanization and pumping ground water. Dams are one of the main origins of man-made flowalteration. River dams and barrages modify natural habitats (in the channel and floodplain) byaltering water and sediment fluxes, and this affects ecohydrological processes, and biotic andabiotic cycles.

There are various significant irrigation canal systems in Ganga Basin which divert water forirrigation. Water is diverted from the main river as well as from tributaries. Below a number ofcanals from the main river are presented (Table 3.1 and Figure 3.3).

Table 11-1: Significant irrigation canal systems in the Ganga River which divert water for irrigation (Parua, 2010)Name Origin Location Present discharge

capacityInitial year ofoperation

Upper GangaCanal

Bhimgoda barrage Haridwar 10500 cusec(300 m3/s)

1854

Eastern GangaCanal

Bhimgoda barrage Haridwar 4850 cusec 1980 approved2010 completed

Madhya GangaCanal

Madhya Gangabarrage

Bijnor 8250 cusec (stage I)4300 cusec (stage II)

1984?Projected

Lower GangaCanal

Narora barrage Narora 9000 cusec(156 m3/s)

1879

64



Figure 11-3.- Network of canals in Upper Ganga Basin. Source: Jain et al., 2007

11.3 Impact of flow alteration on ecology and ecosystem services in the Ganga BasinFlow alteration exerts direct and indirect influences on the river´s ecology and in theecosystem services it provides to society. Derivation of flow-ecology-ESS relationships isrequired to assess potential impacts of water management alternatives. Application of anecosystem services approach can create an adequate context to create bridges betweenflow-ecology relationships and data from the basin´s agents, because it helps integratingeconomics and ecology, and connecting them with human welfare (Kozak et al., 2015).



65

Several ecological functions supported by different river flow levels were summarized byPostel & Richter (2003). This classification may be applicable to the Ganga basin (Table 3.2):

Table 11-2: Relations between river flow characteristics and ecological functionsLow (base) flows Normal level:

· Provide adequate habitat for aquatic organisms· Maintain suitable water temperatures, dissolved oxygen and water

chemistry· Maintain water tables levels in the floodplain and soil moisture for

plants· Provide drinking water for terrestrial animals· Keep fish and amphibian eggs suspended· Enable fish to move to feeding and spawning areas· Support hyporheic organisms (those living in saturated sediments)

Drought level:· Enable recruitment of certain floodplain plants· Purge invasive introduced species from aquatic and riparian

communities· Concentrate prey into limited areas to benefit predators

High pulse flows · Shape physical character of river channel, including pools and riffles· Determine size of stream bed substrates (sand, gravel and cobble)· Prevent riparian vegetation from encroaching into channel· Restore normal water quality conditions after prolonged low flows,

flushing away waste products and pollutants· Aerate eggs in spawning gravels and prevent siltation· Maintain suitable salinity conditions in estuaries

Large floods · Provide migration and spawning cues for fish· Trigger new phase in life cycle (e.g. in insects)· Enable fish to spawn on floodplain, provide nursery area for juvenile

fish· Provide new feeding opportunities for fish and waterfowl· Recharge floodplain water table· Maintain diversity in floodplain forest types through prolonged

inundation· Control distribution and abundance of plants on floodplains· Deposit nutrients on floodplain· Deposit gravel and cobbles in spawning areas· Flush organic materials (food) and woody debris (habitat structures)

into channel· Purge invasive introduced species from aquatic riparian

communities· Disburse seeds and fruits of riparian plant· Drive lateral movement of river channel, forming new habitats

(secondary channels and oxbow lakes)· Provide plant seedlings with prolonged access to soil moisture

Regarding links between the flow regimes determining and upholding the ecologicalprocesses that consequently provide for the ecosystem services and therefore the humanwell-being we present evident examples of causes and effects in a general list of 4 ESS types–flow linkages by Forslund et al. (2009), that can be applicable to the Ganga basin (Table11-3):

66



Table 11-3.- Examples of causes and effects in Ecosystem servicesEcosystem services Human well-being Environmental flow component and

ecological processesProvisioningThe flow regime supportsthe delivery of a range ofdifferent provisioningservices such as cleanwater, plants, buildingmaterials and food

Basic material forgood life

Fish supply: the life cycle of many fish speciesheavily depends on the natural variability inriver flows e.g. large floods are important forfishes being able to migrate as well as spawn.

Medical plants, fruits: drought level enablesrecruitment of certain floodplain plants. Largefloods disburse seeds and fruits of riparianplants.

Water supply: large floods recharge floodplainwater tables.

RegulatingThe environmental flowregime helps controlling,pollution, pests andfloods

Security, Health Flood control: riparian vegetation stabilizesriver banks. Flows that maintain soil-moisturelevels in the banks as well as high flows todeposit nutrients and seeds on the bank willmaintain riparian vegetation.

Pollution control: high pulse flows restoresnormal water quality conditions after prolongedlow flows, flushing away waste products andpollutants.

Pest control: a river with environmental flows ismore resistant against the intrusion of exoticspecies. Damned, diverted and modified riversthat create permanent standing water andmore constant flow regimes provide favorableenvironment for exotic species.

CulturalSpiritual, recreational,aesthetic services

Good socialrelations

Sufficient flows to support aesthetics valuesand contribute to cultural services are animportant component of the environmental flowregime.

SupportingBiodiversity, nutrient andsediment cycling

Basic material forgood life, Security,Health, Good socialrelations

Large floods can maintain balance of speciesin aquatic and riparian communities. They canalso maintain diversity in floodplain forest typesthrough prolonged inundation (different plantspecies have different tolerance)



67

Approach to environmental flow assessment12

To allow informed decision-making on the sustainable use of the Ganga River system, it isimportant to know the consequences any changes in use may have on the ecohydrologicalfunctioning of the Ganga river system and the types of ecosystem services (ESS) this systemoffers to society.

With that major goal, a multi-scale environmental flow assessment will be developed alongthe Ganga River course, applying a consultative process based on sound scientific analyses.

Our approach consists of four steps:a) Review of earlier and on-going environmental flows work and partnerships for theGanga River.b) Basin-wide assessment of hydrological alteration of the Ganga River system.c) Identification of flow-ecology-ESS relationships based on expert judgment.d) Incorporation of information on key relationships collected into modeling frameworkand dashboard.

12.1 Review of earlier and on-going environmental flows work and partnerships for theGanga RiverIndian basins are characterized by large spatial-temporal rainfall and runoff gradients.Flowing water in rivers is mostly connected to the southwest monsoon (June to September),which induces wide inter- and intra-annual flow variations. This, combined with a largediversity of geomorphological and topographical conditions, enhances the existence of manydifferent flow patterns (Amarasinghe et al., 2005; Kumar et al., 2005). Nonetheless, theintense agricultural, industrial and urbanization development enjoyed by the country duringthe last decades has had a major influence on rivers´ flows and ecosystem integrity, due toflow regulation (from hundreds of dams and reservoirs) and pollution (from many point anddiffuse sources). Protection and restoration of rivers are, thus, essential to progressivelyrecover certain levels of quality and health in the Indian rivers. And also to ensure their abilityto sustain biodiversity and vital ecological processes, and to provide multiple ecosystemservices to the Indian people.

Environmental flows can become an important tool to help reach those targets. Theirdissemination and recognition are still incipient throughout the country, but already a numberof initiatives and works have been devoted to providing the theoretical or practicalapproaches needed to implement them in a number of Indian basins. Also attention is beinggiven now to the implications of releasing environmental flows under different climaticscenarios, concerning its potential influence on water uses and users (Hosterman et al.,2012).

Regarding specific analyses aimed at providing improved flow regimes in the Indian basins,Jha et al. (2008) assessed environmental flows in Brahmani and Baitarani rivers in Orissa, bymeans of a FDC-based hydrological method. Kumara & Srikantaswamy (2011) estimated flowrequirements in Tungabhadra River in SW India by means of the indicators of hydrologicalteration (IHAs) and the environmental flow components (EFCs). While Babu & Kumara(2009) proposed using the Montana methods for providing environmental flows in the BhadraRiver, a tributary to the former Tungabhadra River.

68



Those site-specific analyses have been accompanied by other initiatives which tried to framethe state-of-the-art on environmental flows in India, and suggested different procedures toreduce flow alteration in the Indian basins. Among these, the earliest were the IWMI reportsauthored by Smakhtin et al. (2006, 2007), who carried out initial estimations of flowrequirements in many different catchments, discussed the main legal, social and economicconstraints for their release, and proposed a set of recommendations for their successfuldischarge. In other work of an IWMI team, Amarasinghe et al. (2013) studied costs andbenefits of reallocating water from irrigation canals to the river as environmental flows.

In 2012, WWF-India prepared and published an exhaustive report on environmental flows inthe Upper Ganga Basin (800 km-reach from Gangotri to Kanpur) (O´Keeffe et al., 2012), aspart of its Living Ganga Program (LGP) - launched in 2007. The report was based on therecommendations of different working groups, which would give advice about diverse factorsinfluencing environmental flows: hydraulics, hydrology, fluvial geomorphology, biodiversity,livelihood, spiritual/cultural issues, and water quality. The joint activity of all those groupsresulted in the definition of environmental flows for maintenance years (normal years, neithertoo wet nor too dry), environmental flows for drought years, and flood flows for bothmaintenance and drought years. Recommended flows at each site were expressed as apercentage of the natural Mean Annual Runoff (MAR). Study zones and sites were thefollowing:

- Zone 1: Gangotri to Rishikesh. Site: Kaudiyala- Zone 2: Upstream of Garhmukteshwer to Narora. Reference zone (bench-mark to

assess the state of the other three zones)- Zone 3: Narora to Farrukhabad. Site 3: Kachla Ghat- Zone 4: Kannauj – Kanpur. Site: Bithoor

Flow variability was incorporated by giving specific recommendations for monthly andseasonal flow requirements. Design of environmental flows was carried out using the BuildingBlock Methodology (BBM). The WWF report included, in its final sections, different practicalsuggestions which could contribute to making environmental flows a reality in the GangaBasin.

As the most recent milestone in this sequence of raised interest on e-flows, in 2015, theWorld Bank organized a “Workshop on Environmental Flows for Strategic Planning for theGanga Basin”. After its celebration, the Bank published a Report (2015) summarizing themain discussions and conclusions reached in it. The Workshop was based on thecontributions of delegates, who worked -in two groups- in three linked working sessions: i.Identification of barriers and issues to environmental flow assessment and implementation inthe Ganga; ii. Possible solutions to these barriers and iii. Development of a potential ten-pointplan for implementing environmental flows in the Ganga basin:

1. Policy and planning2. Water demand and supply management3. Rights and responsibilities4. Collaboration5. Knowledge base6. Research and analysis7. Trial application8. International case studies9. Training and capacity building10. Awareness building



69

The plan´s recommendations support implementation of the ‘Ganga River Basin ManagementPlan’. The Ganga RBMP was suggested to have at least a 10 years life-span. The Reportproposed the consecution of achievable short (1-3 years) and medium (3-5 years) term stepsto demonstrate good periodic progress. Long-term actions would be those linked to a 5-10years schedule.

12.2 Basin-wide assessment of hydrological alteration of the Ganga River systemTranscendence of the flow regime as a linking element of the river ecosystem, as recognizedby the natural flow regime paradigm (Poff et al., 1997), has direct implications for ourapproach: success in the conservation of the biodiversity and functioning of the Ganga Riverwill mostly depend on the ability to acknowledge, protect and/or restore the main componentsof its non-modified flow regime. Hydrological alteration (distance from modified to non-modified flow components) reflects changing in ‘ecologically-relevant flow parameters’. Thereference situation can be a natural, unregulated situation, or another past situation which isconsidered to be of a desired ecosystem quality.

As a first step aimed at better understanding the alteration of flow components in GangaRiver, a basin-wide assessment of hydrological alterations will be developed throughout thewhole Ganga system. With that objective, hydraulic infrastructures potentially affecting theriver´s flow regime will be identified, and featured. Location, storage/transport capacity,associated uses and year of construction will be determined for each. Lastly, infrastructuresshowing a significant capacity to alter the river´s flow pattern will be spotted, resulting in abasin-wide identification of those reaches which can be suffering different degrees ofhydrologic alteration.

After the basin-wide assessment of hydrologic alteration has been developed, a moredetailed comparative assessment will be carried out in representative river sections byconsidering the non-modified flow temporal series generated by Task 1. This lower-scale flowanalysis will allow a deeper understanding of the specific flow alteration held by the riveralong its main physical and environmental gradients. Assessment will be performed by usingdifferent indicators of hydrologic alteration, selected from the methodologies referred inprevious sections of this document. The complete set of indicators included in thosemethodologies will not be used, since some of them are not of direct interest to characterizethe specific flow attributes of Ganga River. Only those more informative or better linked to theriver´s dynamics and to the project´s approach and objectives will be used and quantified.

To identify river´s reaches with differential hydromorphological and ecological functioning, ariver zoning exercise will be carried out. The river zoning exercise will identify, based ondifferent physical and environmental characteristics, the different hydro-ecological zonesalong the Ganga. In addition, the presence of valuable ecosystem components (largeprotected areas, wetlands, lakes, forests, critical habitats, etc.) will be mapped. Based on thiszoning, a number of indicative reaches and sites will be selected, for which an ecological andsocioeconomic baseline will be carried out, identifying and mapping the key environmentaland socioeconomic values and assets of the basin based on existing data. In case this isneeded, field work, field surveys and broad consultation will be carried out, to collect andinterpret additional data, or to confirm certain hypothesis drawn from the existing data.Ultimately, those analyses will be leading to a more detailed environmental flow assessment.In parallel, environmental and river health objectives will be set in those sites and reaches, toprovide guidance for eflow definition.

70



Flow characteristics considered for evaluating the reference, current and potential futuresituations at the selected river sites will be:

a) Average discharge,b) Mean low season discharge,c) Duration of low (base) or high (pulse) flow period,d) Magnitude,e) Timing and frequency of annual and interannual peak discharges and floodsf) Other relevant flow characteristics follow expert discussions in step 2.

Although determination of flow alteration does not necessarily give insights into its short-,medium- and long-term consequences for the river´s ecosystems, it does help to gainknowledge about where the ecosystems may be most severely affected, which can help focuslater managerial and research activities.

12.3 Identification of flow-ecology-ESS relationships based on expert judgmentRiver Ganga e-flows are required for maintaining critical river processes, allowing river self-purification, maintaining riverine biodiversity, recharging groundwater, supporting livelihoods,maintaining sediment and nutrient movement, preventing saline intrusion in estuarine anddelta areas, providing recreation and fulfilling the cultural and spiritual needs. E-flowsassessment identifies quantity, quality and distribution of flow patterns along the river systemthat determine the subsistence of all living creatures depending on the resources of the RiverGanga.

For establishing links between E-flow characteristics and the river components and processesdelivering the goods and benefits to Ganga society, we will develop an ESS framework thatallows incorporating the ESS in the overall computational modeling framework (includingdashboard) containing the components which form the basis for economic and socialappraisal/trade-off analysis, and comparing the assessment to determine river healthobjectives. The framework will need to foster interdisciplinary research input and contribute toa more sustainable management of the river Ganga river system, while inter alia at leastmaintaining the provision of a set of key ecosystem services over time.

To gain more specific information on the consequences of alterations in flow characteristics,we will organize a process with river experts from different disciplines (e.g. habitat, species,and geo-eco-hydrological processes) to jointly assess under what conditions the ecosystemdegradation or restoration can occur. We will also facilitate training of technical professionalsthrough “learning by doing” to build the capacity for on-going environmental flow assessmentsas a part of an adaptive approach to basin planning and management.

Importantly is to comprehend how the identified flow characteristics drive the key componentsand processes of the Ganga river system that in turn correlate to the delivery a diverse set ofservices which directly and indirectly underpin economic progress and human wellbeing in thebasin.

This process requires at least two expert workshops:1. First meeting: A joint understanding of flow-ESS relationships and preliminary

relationships – many river experts may not yet be familiar with the process of linking theirknowledge on river processes and components to different flow characteristics. Thebasic concepts and how the results are planned to be included in the modeling tool willbe discussed. River zoning, site selection and hydrological alteration will be presented.Subsequently the experts will be asked to comment on river zoning, site selection andflow parameters used. In the next step they will be invited to indicate below or above



71

which thresholds the ecosystem component with which they are familiar is likely to showa marked change. The approach taken should allow for the incorporation on uncertaintyranges.

2. Field visit: the group of expert should visit together at least one of the identified sites tounderstand the actual situation (cross section of river bed and flood plain, flow velocity,morphology, species present).

3. Data collection: in between the first and the second meeting, the experts are invited todisclose any data they may have readily available to improve the flow-ecosystemrelationships identified in the first meeting

4. Hydrological analysis revised: if the experts identified other flow parameters of interestfor the functioning of the ecosystem than were used in the first assessment ofhydrological alteration, new analysis of flow series need to be made to prepare for thesecond meeting.

5. Second meeting: using the information collected in the field, the data the various differentexperts bring in, and the updated hydrological analysis, the relationships identified in thefirst workshop will be updated.

As important input for the expert judgment process, we plan to follow the following steps:a) Produce map of different river zones and their main characteristics and ecosystem

features (e.g. low land area with nature reserve, spawning/breeding site, etc.).b) Run hydrological model simulations for a reference situation (this can be without any

infrastructure/human water use, or the infrastructure/use at a point in time when localexperts though the ecosystem was still functioning well), for the current situation andfor possible future situations (if already available).

c) Analyze the flow regime alteration, using perhaps a few different existing methods(e.g., IHA method by Richter et al., 1996), and the method developed for the Mekong(King and Brown, 2010), and if possible including a simple distinction of seasonalflows based on the seasons in the Ganga basin, for each of the different sites.

d) Produce a map showing what parts of the river system are already impacted bycurrent use or are likely to be severely impacted by future use. Of course, this is onlyaimed at identifying some 'hotspots' - this does not yet include any information onwhat the actual ecosystem impact is, that would require the expert judgment approachdiscussed above.

e) Produced maps can be either the end product of a limited analysis - in which case adiscussion should be added of what can and what cannot be concluded from this andhow to continue, or it can be the starting point of more detailed analysis which couldthen focus on those areas identified as 'hotspots'.

12.4 Incorporation of information collected into modeling framework and dashboardE-flow requirements for each major river zone will be presented, as one key determinant ofriver health, and represented in the river modeling in the form or knowledge rules or otherassociated -and relevant- tools. Evaluation of the knowledge rules will be carried outconsidering the most determinant biotic and abiotic drivers for the Ganga River´s ecologicaldynamics. They will consider information provided by WFlow, SHPY and MODFLOWapplications to understand and interpret annual, monthly and daily flow patterns in the GangaRiver, and to draw critical links between those patterns, and hydraulic habitat, rivergeomorphology, water quality, river ecology, and socioeconomic, cultural and spiritual values.

On this basis, and after the existing knowledge on Ganga´s ecology has been reviewed,interactions between flow features, the extent/quality of habitats, and the provision ofecosystems services will be depicted. This will eventually provide ecology/ESS outputs fordifferent flow scenarios, and will allow feedback for closer analyses of ecohydrological trendsunder a range of managerial alternatives. Assessment and implementation of environmental

72



flows will be boosted by training government professionals in environmental flow conceptsand methods, and in the influence of e-flow scenarios on water planning and management.Thus, promoting the inclusion of e-flows as a part of integrated water resources management.

The implementation of environmental flow regimes throughout the Ganga River basin will beenhanced by suggesting an adaptive management framework, which can later guideoperating rules from the hydraulic infrastructures, application of a monitoring program foradapting future management of e-flows, and other instructions for managers which jointlycontribute to the successful release of e-flows in the Ganga basin.



73

Data requirements13

High, intermediate and low priority data and information requirements have been identified.All of them are necessary to fulfill the goals for Task 3. The priority setting is determined bythe readily availability of the data and its quality and coverage in time and space within theriver Ganga basin. Overview of priority data and information can be found here below.

High priority· Abundance and distribution of selected species (aquatic & riparian) (data & GIS

maps).· Habitat characteristics (extent, distribution, composition) for selected species (data &

GIS maps)· GIS maps of protected/conservation areas· GIS maps of sacred/religious areas· Conservation goals· E-flow goals

Medium priority· Data on water quality and pollutant loads;· Data on ecological requirements of species and habitats· Data on water quality and quantity requirements and ecological relations supporting

ecosystem services provided by the river system· GIS maps with location of hydraulic facilities (water regulation/abstraction)· GIS maps with location of gauge and water quality stations· River geomorphological mapping· GIS maps of tourism pressure· GIS maps of recreation areas

Low priority· Water planning goals· Land planning and typology· River typology and classification· Year of construction, year of initial operation of barrages· Important social and cultural, religious and spiritual requirements· Land use (agricultural, industrial – textile and paper mills, cement, tanneries,

distilleries, chemical plants-, mining, dumping sites, forest)· River use by local communities (fishing, sediment and minerals extraction, power,

water supply, wood, raw material, biomass, medicinal plants, soil fertilizing, cowsdrinking and gatherings)

· Population densities

Data and information sources are being consolidated. State and nation wide manuscripts,relevant national and international reports and website, as well as data depositories, expertknowledge, files and digital mapping layers from official channels are being researched forquality and applicability

74



References14

Acreman, M. & Dunbar, M. J. 2004. Defining environmental river flow requirements – areview. Hydrology and Earth System Sciences 8(5): 861-876. Arthington, A.H., Bunn,S.E., Poff, N.L., Naiman, R.J. 2006. The challenge of providing environmental flowrules to sustain river ecosystems. Ecological Applications 16: 1311–1318.

Amarasinghe, U., Sharma, B. R., Aloysius, N., Scott, C., Smakhtin, V., & De Fraiture, C.2005. Spatial variation in water supply and demand across river basins of India (Vol.83). Iwmi.

Amarasinghe, U. A., Smakhtin, V., Bharati, L., & Malik, R. P. 2013. Reallocating water fromcanal irrigation for environmental flows: benefits forgone in the Upper Ganga Basin inIndia. Environment, development and sustainability 15(2): 385-405.

Babu, K.L., & Kumara, B.H. 2009. Environmental flows in river basins: a case study of RiverBhadra. Current Science 96(4): 475-479.

Barthel Roland and Stefan Banzhaf, 2015. Groundwater and Surface Water Interaction at theRegional-scale. A Review with Focus on Regional Integrated Models. WaterResources Management (2016) 30:1-32. DOI 10.1007/s11269-015-1163-z

Boyd, J. & Banzhaf, H.S. 2007. What are ecosystem services? The need for standardizedenvironmental accounting units. Ecological Economics 63: 616-626.

Brauman, K. A., van der Meulen, S., & Brils, J. 2014. Ecosystem services and river basinmanagement. In Risk-Informed Management of European River Basins (pp. 265-294).Springer Berlin Heidelberg.

Brownbill R.J., Lamontagne S., Williams R.M., Cook P.G., Simmons C.T., Merrick N., 2011.Interconnection of surface and groundwater systems – river losses from losing-disconnected streams. Technical final report, June 2011, NSW Office of Water,Sydney

Bunn, S.E., Arthington, A.H. 2002. Basic principles and ecological consequences of alteredflow regimes for aquatic biodiversity. Environmental Management 30: 492–507.

Byrd, R. H., Lu, P. and Nodedal, J.: A limited-memory algorithm for bound-constrainedoptimization, SIAM J. Sci. Comput., 16(5), 1190–1208, 1995.

CGWB, 2014. Dynamic Groundwater Resource of India (as on 31st March 2011). CentralGroundwater Board

Christensen, N.L., Bartuska, A., Brown, J.H., Carpenter, S., D'Antonio, C., Francis, R.,Franklin, J.F., MacMahon, J.A., Noss, R.F., Parsons, D.J., Peterson, C.H., Turner,M.G., Moodmansee, R.G. 1996. The report of the Ecological Society of AmericaCommittee on the scientific basis for ecosystem management. Ecological Applications6: 665-691.

Costanza, R., D’Arge, R., Groot, R.D., Farber, S., Grasso, M., Hannon, B., Limburg, K.,Naeem, S., O’Neil, R.V., Paruelo, J., Raskin, R.G., Sutton, P. & Belt, M.V.D. 1997.The value of the world’s ecosystem services and natural capital. Nature 387: 253-260.

CWC and NRSC, 2014. Ganga Basin. Version 2.0. Government of India. Ministry of WaterResources. Central Water Commission (CWC) and National Remote Sensing Centre(RSC). 259 pp.

Deltares, 2015. RIBASIM Version 7.01 User Manual Addendum.Doherty, J. E., 2010. Approaches to highly parameterized inversion - A guide to using PEST

for groundwater-model calibration. Tech. Rep. 2010-5169, U.S. Geological SurveyScientific investigations, Reston, Va. U.S. Dept. of the Interior, U.S. GeologicalSurvey.



75

Fernández Yuste, J.A., Martínez Santa-María, C., Magdaleno, F. 2012. Application ofhydrologic alterations in the designation of heavily modified water bodies in Spain.Environmental Science & Policy 16: 31-43.

Fisher, B., Turner, R.K. & Morling, P. 2009. Defining and classifying ecosystem services fordecision making. Ecological Economics 68: 643-653.

Forslund, A., Renöfält, B. M., Barchiesi, S., Cross, K., Davidson, S., Farrell, T., Korsgaard, L.,Krchnak K., McClain, M., Meijer, K. & Smith, M. 2009. Securing water for ecosystemsand human well-being: The importance of environmental flows. Swedish Water HouseReport 24.

Harrison, P.A., Berry, P.M., Simpson, G., Haslett, J.R., Blicharska, M., Bucur, M., Dunford, R.,Egoh, B., García-Llorente, M., Geamana, N., Geertsema, W., Lommelen, E.,Meiresonne, L., Turkelboom, F. 2014. Linkages between biodiversity attributes andecosystem services: A systematic review. Ecosystem Services 9: 191–203.

Heijde , Paul K. M. van der., 1988. Spatial and Temporal Scales in Groundwater Modeling.Chapter 11 from Scales and Global Change, spatial and temporal variability inbiospheric and geospheric processes(http://www.scopenvironment.org/downloadpubs/scope35/chapter11.html)

Hosterman, H. R., McCornick, P. G., Kistin, E. J., Sharma, B., & Bharati, L. 2012. Freshwater,climate change and adaptation in the Ganges River Basin. Water Policy 14(1): 67-79.

IIT, 2014. Surface and Groundwater Modeling of the Ganga River Basin. GRBMP: GangaRiver Basin Management Plan. Report Code: 057_GBP_IIT_ WRM_ANL_02_Ver1_Aug 2014

Jain, S.K., Agarwal, P.K., Singh, V.P. 2007. Hydrology and Water Resources of India. WaterScience and Technology Library, Vol 57, Springer.

Jarvis, A., H.I. Reuter, A. Nelson, E. Guevara, 2008, Hole-filled SRTM for the globe Version4, available from the CGIAR-CSI SRTM 90m Database (http://srtm.csi.cgiar.org)

Jha, R., Sharma, K. D., & Singh, V.P. 2008. Critical appraisal of methods for the assessmentof environmental flows and their application in two river systems of India. KSCEJournal of Civil Engineering 12(3): 213-219.

Karssenberg, D., Burrough, P., Sluiter, R. and de Jong, K.: The PCRASTER software andcourse materials for teaching numerical modeling in the environmental sciences,Trans. GIS, 5, 99–110, doi:10.1111/1467-9671.00070, 2001.

Karssenberg, D., Schmitz, O., Salamon, P., de Jong, K. and Bierkens, M. F. P.: A softwareframework for construction of process-based stochastic spatio-temporal models anddata assimilation, Environ. Model. Softw., 25(4), 489–502,doi:10.1016/j.envsoft.2009.10.004, 2010.

King, J. and Brown, C., 2010. Integrated basin flow assessments: concepts and methoddevelopment in Africa and South-east Asia. Freshwater Biology 55(1):127-146.

Kozak, J.P., Bennett, M. G., Hayden-Lesmeister, A., Fritz, K. A., & Nickolotsky, A. 2015.Using Flow-Ecology Relationships to Evaluate Ecosystem Service Trade-Offs andComplementarities in the Nation’s Largest River Swamp. EnvironmentalManagement 55(6): 1327-1342.

Kumara, B.H. & Srikantaswamy, S. 2011. Environmental flow requirements in TungabhadraRiver, Karnataka, India. Natural resources research 20(3): 193-205.

Kumar, R., Singh, R. D., & Sharma, K.D. 2005. Water resources of India. Current Science89(5): 794-811.

Lehner, B., Verdin, K. and Jarvis, A.: HydroSHEDS Technical Documentation Version 1.0.,2006.

MacDonald AM, Bonsor HC, Taylor R, Shamsudduha M, Burgess WG, Ahmed KM,Mukherjee A, Zahid A, Lapworth D, Gopal K, Rao MS, Moench M, Bricker SH, YadavSK, Satyal Y, Smith L, Dixit A, Bell R, van Steenbergen F, Basharat M, Gohar MS,

76



Tucker J, Calow RC and Maurice L., 2015. Groundwater resources in the IndoGangetic Basin: resilience to climate change and abstraction. British GeologicalSurvey Open Report, OR/15/047, 63pp.

Magdaleno, F. 2009. Manual técnico de cálculo de caudales ambientales. Colegio deIngeniero de Caminos, Canales y Puertos. 240 p.

Magdaleno, F. 2011. ¿Debe el agua de los ríos llegar al mar? Una gestión medioambientaldel agua en España. Ed. Los libros de la Catarata - Fundación Alternativas. 106 p.

Magdaleno, F. 2014. How can a river be hydrologically restored? Technical note 5. CIREFand Wetlands International. 6 p.

Martínez Santa-María, C. & Fernández Yuste, J.A. 2006. Índices de alteración hidrológica enecosistemas fluviales. Monografía M-85 CEDEX. Secretaría General Técnica,Ministerio de Fomento. 178 p.

McDonald, M. and A. Harbaugh, 1988. A modular three-dimensional finite-difference ground-water flow model: Techniques of Water-Resources Investigations of the United StatesGeological Survey Tech. rep., USGS.

McLeod, K.L., Lubchenco, J., Palumbi, S.R., Rosenberg, A.A. 2005. Scientific ConsensusStatement on Marine Ecosystem-Based Management. Signed by 221 academicscientists and policy experts with relevant expertise and published by theCommunication Partnership for Science and the Sea.

Miller, J.E., 1984. Basic Concepts of Kinematic-Wave Models. USGS Paper 1302,Washigton, USA.

Nash, J. E. and Sutcliffe, J. V.: River flow forecasting through conceptual models part I — Adiscussion of principles, J. Hydrol., 10(3), 282–290, 1970.

O´Keeffe, J., Kaushal, N., Bharati, L., & Smakhtin, V. 2012. Assessment of environmentalflows for the Upper Ganga Basin. WWF-India. Delhi, India, 162 p.

Parua, P.K. 2010. The Ganga: water use in the Indian subcontinent (Vol. 64). SpringerScience & Business Media.

Poff, N.L., Richter, B.D., Arthington, A.H., Bunn, S.E., Naiman, R.J., Kendy, E., Acreman, M.,Apse, C., Bledsoe, B.P., Freeman, M.C., Henriksen, J., Jacobson, R.B., Kennen,J.G., MerriF, D.M., O’Keefe, J.H., Olden, J.D., Rogers, K., Tharme, R.E., Warner, A.2010. The ecological limits of hydrologic alteration (ELOHA): a new framework fordeveloping regional environmental flow standards. Freshwater Biology 55: 147–170.

Poff N.L., Allan J.D., Bain M.B., Karr J.R., Prestegaard K.L., Richter B.D., Sparks R.E. &Stromberg J.C. 1997. The natural flow regime: a paradigm for river conservation andrestoration. BioScience, 47, 769– 784.

Poole, G.C. 2002. Fluvial landscape ecology: addressing uniqueness within the riverdiscontinuum. Freshwater Biology 47(4): 641-660.

Postel, S. & Richter, B.D. 2003. Rivers for life: Managing Water for People and Nature. IslandPress: Washington, DC.

Richter, B.D., Baumgartner, J.V., Powell, J., Braun, D.P. 1996. A Method for AssessingHydrologic Alteration within Ecosystems. Conservation Biology 10(4): 1163-1174.

Richter, B.D. 2010. Re-thinking environmental flows: from allocations and reserves tosustainability boundaries. River Research and Applications 26(8): 1052-1063.

Schmitz, O., Karssenberg, D., de Jong, K., de Kok, J. L. and de Jong, S. M.: Map algebra andmodel algebra for integrated model building, Environ. Model. Softw., 48, 113–128,doi:10.1016/j.envsoft.2013.06.009, 2013.

Shiao Tien, Andrew Maddocks, Chris Carson and Emma Loizeaux, 2015. 3 Maps ExplainIndia’s Growing Water Risks. http://www.wri.org/blog/2015/02/3-maps-explain-india’s-growing-water-risks

Smakhtin, V.Y. 2006. An assessment of environmental flow requirements of Indian riverbasins (Vol. 107). IWMI.



77

Smakhtin, V., Arunachalam, M., Behera, S., Chatterjee, A., Das, S., Gautam, P., Joshi, G.D.,Sivaramakrishnan, K.G. & Unni, K.S. 2007. Developing procedures for assessment ofecological status of Indian river basins in the context of environmental waterrequirements (Vol. 114). IWMI.

Stewardson, M.J. & Gippel, C.J. 2003. Incorporating flow variability into environmental flowregimes using the flow events method. River Research & Applications 19: 459–472.

Terink, W., Lutz, A. F., Simons, G. W. H., Immerzeel, W. W. and Droogers, P.: SPHY v2.0 :Spatial Processes in HYdrology, Geosci. Model Dev., 8, 2009–2034,doi:10.5194/gmd-8-2009-2015, 2015a.

Terink, W., Lutz, A. F. and Immerzeel, W. W.: SPHY v2.0: Spatial Processes in Hydrology:Model theory and SPHY interface (v1.0) manual, Wageningen, The Netherlands.,2015b.

The World Bank. 2015. Report of the Workshop on Environmental Flows for StrategicPlanning for the Ganga Basin. Delhi, India, 32 p.

Tharme, R.E. 2003. A global perspective on environmental flow assessment: emerging trendsin the development and application of environmental flow methodologies for rivers.River Research and Applications 19: 397–441.

Van der Krogt, W.N.M, 2008. RIBASIM Version 7.00. Technical Reference Manual .Deltaresreport T2478.00. 185 pp.

Van der Krogt, W.N.M and A. Boccalon, 2013. River Basin Simulation Model RIBASIMVersion 7.00. User Manual. Deltares project 1000408-002. 213 pp.

Vermeulen, P.T.M, L.M.T. Burgering and B. Minnema, 2016. iMOD user manual. Version: 3.3,March 2016. Deltares, The Netherlands. (http://oss.deltares.nl/web/iMOD).

Winter Thomas C., Judson W. Harvey, O. Lehn Franke and William M. Alley, 1998. GroundWater and Surface Water A Single Resource. U.S. Geological Survey Circular 1139.

78



Annex 1 Data requirements

Data collection with CWCTime series of monthly and daily average discharge, reservoir and river water level can beused in any digital format that can be easily converted into the database (such as CommaSeparated Value files, .csv, or MS Excel, .xls, files). Furthermore, a digital map (ESRI Shapefile, .shp) is needed with the location of all monitoring stations. The time series and thelocations on the map should be linked by corresponding codes or names.

For the rating curves a table of measured water level and discharge is required, along withthe derived relation (again as .csv or .xls files with names or codes to link the rating curves totimes series and locations on the map).

Digital maps of the following topics are requested from CWC:· Population data per district· River network (including river name)· Canal network (including canal name, capacity and type: irrigation or drainage)· Hydraulic infrastructure (including name and type: barrage, dam, reservoir, gate,

pumping station)

With respect to the hydraulic infrastructure, data as in the following tables are needed. Not allfields are relevant for all structures. A narrative is requested describing the operation rulesand priorities used when deciding on the operation of the reservoirs. Where relevant, areference is requested to an agreement, law or policy document on which the operationalrules are based.



79

NameTypeRiverID in shape fileLocation XLocation YHydropower (Y/N)Irrigation (Y/N)Industrial water supply (Y/N)Drinking water supply (Y/N)Cooling water supply (Y/N)River flow demand (Y/N)Names of downstream canalsDivision of outflow over canals (%)Full reservoir level (m)Main gate level (m)Narative description operationrules and priorities, includingdivision of downstreams uses,canals and the river

HydropowerHydropower intake level (m)Downstream water level (m)Plant load factor (%)Auxiliary energy consumption (%)

Reservoir / barrage / dam / weir / pumping station

Level Surface area Volume Net head Discharge Net head Dischargefrom low to high [m] [ha] [Mcm] [m] [m3/s] [m] [m3/s]

123456789

101112131415

Main gateSpillway gateLevel-surface area-volume relation

80



The tables below list the stations for which water quality data have been requested fromCWC.

Net head Power Capacity Net head Efficiency Discharge Head loss Discharge Tail race water level[m] [Mw] [m] [%] [m3/s] [m] [m3/s] [m]

Turbine characteristics

Firm energydemand

Floodcontrol level

Targetlevel

Firm storagelevel

River flowdemand

Irrigationwater demand

Industrialwater demand

Cooling waterdemand

Drinking waterdemand

Month (GWh/month) (m) (m) (m) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)January

FebruaryMarch

AprilMayJuneJuly

AugustSeptember

OctoberNovemberDecember



81

S.No. Unique No. Name of SiteRiver Name/Tributary/SubTributary

Station Start date Station end date

1 3 Ankinghat Ganga 14/02/1974 31/05/2016

2 9 Balrampur Ganga/Ghaghra/Rapti 01/05/1976' 31/05/2016

3 14 Bareilly Ganga/Ramganga 12/01/1981' 31/05/2016

4 19 Bewar Ganga/kali 01/07/1976' 31/05/2016

5 22 Bhitaura Ganga 01/06/1976' 31/05/2016

6 23 Birdghat Ganga/Ghaghra/Rapti 01/04/1962' 31/05/2016

7 30 ChhatangAllahabad Ganga 01/01/1972' 31/05/2016

8 33 Chopan Ganga 01/09/1963' 31/05/2016

9 34 Dabri Ganga/Ramganga 01/08/1985' 31/05/2016

10 38 Deoprayag Ganga 09/11/1976' 31/05/2016

11 39 Deoprayag Ganga/Bhagirath 16/11/1974 31/05/2016

12 46 Duddhi Ganga/Sone/Kanhar 01/06/2004' 31/05/2016

13 49 Elginbridge Ganga/Ghaghra 13/01/1964 31/05/2016

14 54 Fatehgarh Ganga 01/12/1980' 31/05/2016

15 62 Garhamukteshwar Ganga 01/12/1980' 31/05/2016

16 64 Ghat Ganga/Ghaghra/Sharda/Sarju 01/05/2006' 31/05/2016

17 67 GoverdheyGhat Ganga/Sone 01/03/2004' 31/05/2016

18 79 Jaunpur Ganga/Gomti 27/04/1978 31/05/2016

19 81 Jhukoo Ganga/Sone/Gopad 01/11/1980' 31/05/2016

20 83 Kachlabridge Ganga 01/11/1980' 31/05/2016

21 89 Kanpur Ganga 15/09/1970 31/05/2016

22 96 KuldahBridge Ganga/Sone 01/11/1980' 31/05/2016

23 103 Lucknow Ganga/Gomti 02/07/1973' 31/05/2016

24 106 Maighat Ganga/Gomti 09/06/1963' 31/05/2016

25 112 MejjaRoad Ganga/Tons 14/07/1976 31/05/2016

26 113 Mirzapur Ganga 31/05/1976 31/05/2016

27 117 Moradabad Ganga/Ramganga 21/11/1980 31/05/2016

28 123 Narhan Ganga/Karamnasa 02/01/2004' 31/05/2016

29 127 Neemsar Ganga/Gomti 15/01/1977 31/05/2016

30 129 Paliakalan Ganga/Ghaghra/Sharda 08/01/1964' 31/05/2016

31 139 Rampur Ganga/Ramganga/Kosi 01/12/1980' 31/05/2016

32 140 Regauli Ganga/Ghaghra/Rapti 01/06/1976' 31/05/2016

33 143 Rishikesh Ganga 20/10/1971 31/05/2016

34 151 Satna Ganga/Tons 01/11/1980' 31/05/2016

35 154 Shahzadpur Ganga 01/12/1980' 31/05/2016

36 158 Sultanpur Ganga/Gomti 11/05/1994' 31/05/2016

37 168 Turtipar Ganga/Ghaghra 03/10/1963' 31/05/2016

38 171 Uttarkashi Ganga/Bhagirath 01/06/1989' 31/05/2016

39 172 Varanasi Ganga 17/08/1963 31/05/2016

WATER QUALITY DATA OF CWCUGBO LUCKNOW

82





1 1 A.B.RoadCrossing Ganga/Yamuna/Chambal/Parwati/Parwati

02/01/1978 31/05/2016

2 2 Agra(P.B.) Ganga/Yamuna 01/10/1976' 31/05/2016

3 4 Auraiya Ganga/Yamuna 01/01/1981' 31/05/2016

4 12 Banda Ganga/Yamuna/Ken 01/01/1972' 31/05/2016

5 13 Baranwada Ganga/Yamuna/Chambal/Banas/Banas

02/01/1978 31/05/2016

6 15 Barod Ganga/Yamuna/Chambal/Kalisindh/Kalisindh

02/01/1978 31/05/2016

7 37 DelhiRlyBridge Ganga/Yamuna 23/03/1963 31/05/2016

8 44 Dholpur Ganga/Yamuna/Chambal 01/12/1976' 31/05/2016

9 51 Etawah Ganga/Yamuna 01/01/1972' 31/05/2016

10 56 Galeta Ganga/Yamuna/Hindon 01/12/1976 31/05/2016

11 63 Garrauli Ganga/Yamuna/Betwa/Dhasan 01/03/1983' 31/05/2016

12 66 GokulBarrage(Mathura) Ganga/Yamuna 01/06/2006' 31/05/201613 69 Hamirpur Ganga/Yamuna 01/01/1981' 31/05/2016

14 94 Khatoli Ganga/Yamuna/Chambal/Parwati/Parwati

07/01/1978 31/05/2016

15 111 Mawi Ganga/Yamuna 12/12/1988 31/05/2016

16 115 Mohana Ganga/Yamuna 11/01/1983 31/05/2016

17 128 Pachauli Ganga/Yamuna/Sind 01/11/1980' 31/05/2016

18 132 Paonata Ganga/Yamuna 31/05/1978 31/05/2016

19 135 Pratappur Ganga/Yamuna 01/01/1983' 31/05/201620 152 Seondha Ganga/Yamuna/Sind 01/05/1972' 31/05/2016

21 153 Shahijina Ganga/Yamuna 12/01/1964' 31/05/2016

22 162 Tonk Ganga/Yamuna/Chambal/Banas/Banas

01/04/1992 31/05/2016

23 166 Tuini(Tons) Ganga/Yamuna/Tons 31/05/1978 31/05/2016

24 169 Udi Ganga/Yamuna/Chambal 01/01/1972' 31/05/2016

25 173 Yashwantnagar Ganga/Yamuna/Giri 28/05/1978 31/05/2016

YBONEWDELHI



83

Data collection with statesThe tables for data regarding hydraulic infrastructure have been presented above for CWC.The states are requested to supply the same data for the important infrastructure within theirjurisdiction. The same applies to the time series of discharges and water levels.

The states are requested to provide a complete overview the sources of water used and thedemand they serve. The following types of sources are distinguished for this purpose:

· Groundwater aquifers distinguished by location and depth· Rivers distinguished by location and inlet (reservoir/dam/barrage/weir/pumping

station)· Canals



15 Azmabad Ganga 16/07/1963 31/05/2016

210 Baltara Ganga/Kosi 01/01/1963 31/05/2016

325 Buxar Ganga 01/07/1966 31/05/2016

442 DhengBridge Ganga/Kosi/Bagmati 01/01/1976 31/05/2016

548 Ekmighat Ganga/Kosi/Bagmati/Adhwara 01/01/2006 31/05/2016

650 Englishbazar Padma/Mahananda 03/08/1964 31/05/2016

752 Farakka Ganga 31/08/1964 31/05/2016

853 Farakka/(HR) Bhagirathi/FeederCanal 01/01/1976 31/05/2016

957 Gandhighat Ganga 01/05/1967 31/05/2016

1071 Hathidah Ganga 16/07/1963 31/05/2016

1172 Hayaghat Ganga/Kosi/Bagmati 01/01/1963 31/05/2016

1273 Hendegir Hoogly/Damodar 01/01/2007 31/05/2016

1375 JaiNagar Ganga/Kosi/Kamla-Balan 01/01/1976 31/05/2016

1476 Japla Ganga/Sone 15/11/1978 31/05/2016

1580 Jhanjharpur Ganga/Kosi/Kamla-Balan 01/01/1963 31/05/2016

1695 Koelwar Ganga/Sone 13/08/1963 31/05/2016

1798 Labha Ganga/Mahananda 16/01/1968 31/05/2016

1899 Lakhisarai Ganga/Kiul 15/01/1977 31/05/2016

19101 Lalganj Ganga/Gandak 17/07/1963 31/05/2016

20105 Maharo Bhagirathi/Mayurakshi 01/01/2007 31/05/2016

21155 Sikanderpur Ganga/BurhiGandak 01/01/1963 31/05/2016

22164 Triveni Ganga/Gandak 16/07/1963 31/05/2016

LGBOPATNA

84



For each of these three sources in their territory the states are requested to supply data howmuch water is demanded (gross) for the following types of water demand for each month ofthe year:

· Irrigation· Industrial water supply· Drinking water supply· Cooling water· River flow demand

The data can be provided for each source of water separately in the following tables.

NameDescriptionTypeStateDistrict(s)Types of industryCropsLocation of inflowLocation of return flow% return flow

Riverflowdemand

Irrigationwaterdemand

Industrialwaterdemand

Coolingwaterdemand

Drinkingwaterdemand

Month (m3/s) (m3/s) (m3/s) (m3/s) (m3/s)January

FebruaryMarch

AprilMayJuneJuly

AugustSeptember


acquifer/river/canal



85

For irrigation additional information is required for each different cropping pattern:

Data collection with CPCBIn this section the most important data for water quality are listed, based on CPCB report2013.

Measured quality in surface wateri. CPCB report 2013 reports on data originating from 2011 that are measured under the

national monitoring programmeii. 2011 data are compared against previous 6 years (2006-2010) mostly in bar charts

only, sometimes with numbers in the graphs. Concentrations do not seem to vary toomuch over the years. Can we derive trend the data by relating it to the average flowdata (activity during the calibration/validation phase of the water quality model)

iii. Presentation is always longitudinal (but not scaled to river length).iv. Data are not the monthly measurements but statistical averages. For 2011 giving min,

mean, maxv. For 2006-2011 giving mean per year (this is not so useful data as the data are

certainly not distributed normally)vi. there are more water quality measurements available in the report, not yet in the

database. For example on page 15 there are data for individual years 2006-2010 perstation too (averaged over time).

NameCodeCrop 1 2 3 4 5NameCultivated area (ha)Field percolation (mm/day)Return flow (%)Supply from surface water (%)Supply from groundwater (%)Surface water conveyance efficiency (%)Groundwater conveyance efficiency (%)Field application efficiency (%)Crop water demand (mm/day)

JanuaryFebruary

MarchAprilMayJuneJuly

AugustSeptember


86



Waste Water per cityi. Of all cities directly on Ganga river there is a list of these cities and their wastewater

production in MLDii. Same table has per city the total treatment capacity, in MLD. We can thus calculate

the load per city if we assume concentrations for treated and untreated wastewater.iii. Available for 49 citiesiv. Total 2700 MLDv. Treated BOD concentration varies widely (1-66)vi. No information on other parameters than BOD (request CPCBP)

Waste water per STPi. For the same cities there is a list with STP with capacity in MLD and the

concentrations of inlet and outlet (treated) for bod and cod. These are individualSTP's, not necessarily representative for all STP in a city (chapter 4)

ii. Find out if these values are typical and can be used for load estimates per city(chapter 4). First compare actual wastewater capacity to the total production per city.Also compare to literature.

Canals and Drains:i. 138 point sources with total of 6000 MLD (this is 2x times the amount of the STP)ii. The total load is probably more than 4x the STP load as drains are assumed 100%

untreatediii. Average BOD load 160mg/L (range 100-200)iv. Table 6.1 & 6,3 use “Catchment-Region”, Table 6.2 uses “Catchment Area”, Table 6.4

uses “City” and Table 6.5 a location description.v. Schematic flow diagrams may be used directly for schematization in Ribasim. To

support schematization in Ribasim we need:a. A decent canals map including names for the canals (asked Hrendra)b. Map with exact locations of STP (asked Sunil/Paras)c. Map with industries / industrial regions (tba)d. Map with drains and STP-lines would help but is most likely not available and

too much detail for now.e. Road map sometimes helps for orientation too (e.g. p64)

vi. Regions mentioned in the flow diagrams (e.g. on page 52) are not official GIS entity(there is no region layer). The name of a region originates from the nearby city.

Industrial pollutionThe following information on Industrial pollution (800 sources) are available:

· Name and Address of the Unit· Type of Industry (9 categories, see below)· State· Water Consumption (industrial) (m3/day)· Waste Water Generation (m3/day)· Canal/Drain/ Subtributary· Name of River/ tributary

Conceptualization of River Basin Model, Surface water ...

Documents

Transcript of Conceptualization of River Basin Model, Surface water ...