IWRM-Ecosystems

7/29/2019 IWRM-Ecosystems

1/47

I. Concept of Ecosystem and Aquatic Ecosystems

IWRM and ECOSYSTEMS

Brij GopalCentre for Inland Waters in South Asia

NATIONAL INSTITUTE OF [email protected]

Training of Trainers on IWRM

Kandy, Sri Lanka, Sept. 2010


2/47

AIR without Water

Full of noxious gases and

particulates that will never

return to land

IWRM- Integrated Water Resource Management

WATER: An Integrating Force

LAND without Water

Rocks will never turn into soils

that provide nutrients to plants.weathering- salinity- erosion- peat formation

NO LIFE exists without Water


3/47


4/47

Precipitation

Interception

Evaporation

Transpiration

Stem Flow

Runoff

Throughfall

Infiltration Subsurface Flow

Evaporation

Uptake

Plants are not simply

Water Users

But also Water Providers

Interception, Infiltration, Obstruction,

Transpiration

Transfer to Animals and Humans


5/47


6/47

Soil

Water

Air

Energy

Abiotic

Primary Producers

Herbivores(Grazers)

Carnivores

Decomposers

(Microbes)

Biotic

Structural Attributes

ECOSYSTEMS

Ecosystem:

dynamically interacting

community of plants,

animals, and micro-

organisms, together

with their non-livingenvironment,

constituting a functional

unit


7/47

Interactions in an Ecosystem

heat

Producers Consumers

Decomposers

heat

Nutrients

Nutrients

Energy


8/47

AQUATIC

ECOSYSTEMS

Rivers, Lakes, Thermal

Springs, Oceans,

Groundwater

Wetlands: Bogs Marshes

Swamps Estuaries

Lagoons Mangroves


9/47

Rivers and Lakes

are NOT

Water Storages

They are Ecosystems


10/47

Wetlands

Marshes and Swamps make the dividebetween terrestrial and aquatic habitats fuzzy


11/47

Humans did not originate in Water

Humans do not live in Water

Millions of organisms

- from bacteria and algae to fish, dolphins and whales -would not exist outside water!

Humans use water for themselves

All other organisms use water to provide goods and servicesthat humans cannot obtain by using water

Besides humans,

all other organisms are genuine stakeholders in water

Water is NOT just a Commodity for Humans


12/47

What do Aquatic Ecosystems do for Us?

and

What do we do to them?


13/47

II. Ecosystem Services and Environmental Flows

IWRM and ECOSYSTEMS


14/47

Ecosystem Services

Millennium ecosystem Assessment (2005).. .. the benefits derived by the humans from

ecosystems

The term was first coined by Ehrlich & Ehrlich (1981)Earlier referred to as environmental services or natures

services

Daily (1997) defines ecosystem services as:the conditions and processes through which

natural ecosystems, and the species that make them up,sustain and fulfill human life


15/47

Ecosystem Services

Scott et al. (1998) elaborates:Processes are interactions among elements of theecosystem,

Functions are aspects of the processes that affect humans

or key aspects of the ecosystem itself...

Services are attributes of ecological functions that arevalued by humans

De Groot et al. (2002) define functions as

the capacity of natural processes and components toprovide goods and services that satisfy human needs.

Thus, processes lead to functions, which lead to services.


16/47

Provisioning Food, Fodder, Fuel, Fiber, Fresh water,

Biochemicals, Genetic material

Regulating Climate, Hydrology, water Quality, Erosion,Natural Hazards, Pollination

Cultural Spiritual, Recreational, Aesthetic,

Educational

Supporting Soil formation, Nutrient cycling, Biological

production

ECOSYSTEM SERVICES


17/47

What do Aquatic Ecosystems do for Us?


18/47

Purification and Processingare dependent upon the

kind, nature and functions ofecosystems

Uptake = Removal = Purification

Processing = Converting to non-

polluting or useful form

Rivers are known for their Purification ability.

H th i 10 O ti i ti f th t t f t l lik i i b ff


19/47

Hypothesis 10: Optimization of the structure of ecotonal zones likeriparian buffer zones,

wetlands or floodplains is a main tool for the reduction of nutrient transfer from

the catchment to the river and other downstream recipients.


20/47

ASSIMILATIVE CAPACITY

etermined by

A. Physical and chemical conditionsRivers Assimilative Capacity is determined by

River orderChannel size and morphologyFlow volume and velocityWater quality

B. Ecosystem characteristics

For example

Plankton populationsAnimal populations (Fish, Amphibia, Birds)

Riparian vegetation


21/47

Values of Aquatic Ecosystems

Providing HabitatModeration of Physical Conditions (weather)

Change in Temperature (Energy Absorption)

Change in Relative Humidity (Evapotranspiration)

Water Infiltration (Groundwater Recharge)Change in Water Flow Velocity

Checking Erosion

Changes in Chemical EnvironmentReduction in Carbon Dioxide

Production of Oxygen

Uptake of Chemical Substances (Nutrients, Toxics)

Production of Chemical Substances


22/47

SERVICES Examples

Provisioning

Food Production of fish, wild game, fruits, and grains (rice)

Fresh water Storage and retention of water for domestic, industrial, and

agricultural use

Fiber and fuel Production of timber, fuelwood, peat, fodder

Biochemical Extraction of medicines / biochemicals from biotaGenetic materials Genes for resistance to plant pathogens, ornamental

species, etc.

Ecosystem Services of Aquatic Ecosystems


23/47

Regulating

Climate regulation Source of and sink for greenhouse gases;

Influence local and regional temperature,

precipitation, and other climatic processes

Water regulation

(hydrological flows)

Groundwater recharge/discharge

Water purification

and waste treatment

Retention, recovery, and removal of excess

nutrients and other pollutants

Erosion regulation Retention of soils and sediments

Natural hazard

regulation

Flood control, storm protection

Pollination Habitat for pollinators



24/47

Cultural

Spiritual and

inspirational

aspects

source of inspiration; many religions attach spiritual and

religious values (sacred lakes, rivers)

Recreational Opportunities for recreational activities

Aesthetic Scenic beauty or enhancement of aesthetics of landscape

Educational Opportunities for formal and informal education and training

SupportingSoil formation Sediment retention and accumulation of organic matter

Nutrient cycling Storage, recycling, processing, and acquisition of nutrients



25/47

What do we do to them?


26/47


27/47

Dams and Barrages

(Storage and Diversion)

How do we manage Water?

Embankments(Flood control, Navigation)

Wastewater

Discharge

Altered Flow Regimes

Altered Wetlands

Decline in Fisheries

Loss of

Floodplains

Altered

Flow Regimes

and Water Quality

Loss of Livelihoods


28/47

Why do we need FLOW in our rivers?

Upstream vs Downstream Communities

Specific Reaches vs Entire River vs Coastal AreasOR

River Basin

Bathing, swimming, rafting?Fishing? Sediments (Gravel, Sand)?

Waste assimilation?Groundwater recharge?

Birds? Wildlife? Floodplain Grazing?

What does the community value more?Off-stream benefits OR In-Stream benefits


29/47

Water is also important for

Ecosystem ServicesBesides for Transport, and Waste Assimilation

Domestic use, Agriculture or Industry

Environmental Flow

The ecosystem conditions sought to be achieved

through EFs is determined

Not just by the quantity of water but also Quality, and Water availability in time and space

Connectivity, abundance and timing


30/47

Definition

Water that is left in a river ecosystem, or releasedinto it, for the specific purpose of managing thecondition of that ecosystem

Identifying the value of various ecosystem services Linking them to the flow and then

Reserving a part of it to achieve the desired level of

ecosystem condition worked on the basis of trade

offs/consensus among water use communitiesEnsuring that the reserved water is delivered in the

right amounts, to the right places at the right times


31/47

Different parts of the flow regime elicit differentresponses from the river ecosystem and removalof one part of the flow regime will affect theecosystem differently than removal of another.

Identify the different parts of the flow

describe in isolation the probable consequences

of partial or whole removal of any one of these

parts

re-combined in various ways, to describe theriver condition of any flow regime of interest


32/47

Low flows:occur when river is not in flood. Define whetherthe river flows all year.Creating varying conditions duringseasons dictating which (and how many) biotic species occurat any time of the year

Small (relatively frequent) floods:Stimulatespawning in fish, flush out poor quality water, cleanse the riverbed, sort the river stones by size, creating different kinds ofhabitat. Trigger and synchronize activities as varied asupstream migrations of fish and germination of seedlings onriver banks

Large Floods (infrequent) floods:Provide scouringflows that shape the channel. Move and cleanse cobbles andboulders on the river bed, recharge soil moisture on banks,inundate backwaters and secondary channels, and floodplains

Flow variability Promotes diversity and resilience to

disturbance


33/47

COMPONENTS OF RIVER FLOW

Volume: depth, area, velocity

Duration: each yearAmplitude of variationFrequency of variation

Timing of the year

All flow components and their interactionsinfluence the habitat and biota differently.

Effect of Flow on Habitat Characteristics


34/47

www.shorelandmanagement.org/depth/rivers/04.html

Meangradient Distance

downstreamBoulders andcobbles

Bed material size

Gravel Sand Silt

The predominantsubstrate sizedecreasesdownstream

www.usda.gov/stream_restoration/chap

Effect of Flow on Habitat Characteristics


35/47

Longitudinal

Important for migration between breeding

and feeding grounds

Prevents genetic isolation

Lateral

Allows species reaching floodplains

Prevents isolation and elimination of

floodplain species

Connectivity


36/47

Connectivity

LateralLongitudinal

Feedingground

Spawningground

Courtesy: Robin Welcomme


37/47


38/47


39/47

U/s River Flow

D/s River Flow

Agriculture

Groundwater

Waterbodies(fisheries)

Floodplain

Agriculture

Flooodplain

River Fisheries

Biodiversity

Grazing/Fuel

Resources

Riverbed

Agriculture

Erosion

(sediment movement)

River shifting

Groundwater

Flow eliminated

X X X

X


40/47

Ecosystem Services Dependent upon Flow

Transport and deposition of sediments along river course

Watering Floodplain wetlands

Recharging groundwater

Moderation of salinity

Role of Floodplains

Supply of good quality waterResources: fish, reeds and forage

Purification of wastesFlood protection

Agriculture and fisheries

Recreation, aesthetics, social-cultural activityEco-tourism

Support estuarine and marine speciesSupport terrestrial species

livelihoods, food, income, quality of life for communities

Methods for Environmental Flows


41/47

Hydrological:Complexity- Low. Data needs: Mainly desktop; Some virginnaturalistic historic flow records Expertise: hydrological, ecological

Hydraulic rating: Complexity: Low- Medium. Data needs: Discharge linkedto hydraulic variables - typically single river cross-section Expertise:

Hydrological, hydraulic modelling, ecological

Habitat Simulation: Complexity: Medium

High. Data needs: desktop andfield, Historical flow records, many hydraulic variables multiple cross-

sections, Physical habitat suitability data for target species. Expertise:

Advanced hydrological modelling, advanced computer-based hydraulic and

habitat modelling, specialist ecological expertise on physical habitat-flow

needs of target species

Holistic: Complexity Medium High. Data needs: + many hydraulicvariables multiple cross-sections, biological data on flow- and habitat-

related requirements of all biota and ecological components. Expertise: As

above




42/47


F l o w

Hydrological

Hydraulic

Habitat

U

sableHabita

tArea


43/47

Framework approaches

Drawing and synthesising the best information from

precise, site and reach-based studies

general models

professional advice

Objective oriented, e.g. IFIM procedure (Instream Flow

Incremental Method), popular in UK and USA

Scenario based e.g DRIFT procedure (Drawdown

Response to Imposed Flow Transformation), developed and

practiced in South Africa.


44/47

Downstream

Response to

Imposed

Flow

Transformation

(DRIFT)

method for theassessment of

EF requirement



45/47

Method Data and

Timerequirements

Appr.

duration ofassessment

Confi-

denceoutput

Levels of

experience

Prescriptive Tennant

method

Moderate to

low

Two weeks Low USA/extensive

Wetted

perimetermethod

Moderate 2-4 months Low USA/Extensive

Expert

panels

Moderate to

low

1-2 months Medium Australia/very

limited

Holistic

Method

Moderate to

high

6- 18

months

Medium Australia/Very

limited

Interactive IFIMInstream Flow

Incremental

Methodolgy

Very high 25 Years High USA, UK,

Extensive

DRIFTDownstream

Response to

Imposed Flow

Tranformation

High to very

High

1-3 Years High Lesotho, South

Africa/very

limited



46/47

No agreement on methods or any common method

All available methods developed for the specific

conditions of small, headwater streams

Not suitable for large, lowland, monsoon-fed rivers

Ecosystem services and livelihoods need to be considered


47/47

IWRM-Ecosystems

Documents

Transcript of IWRM-Ecosystems