Proacc Proposal - Impacts on Sediment Due to Climate Change and Human Activities in the Mekong River...

PROACC proposal by Bikesh Shrestha

PRoACC

Research Proposal

On

Impacts on Sediment Due to Climate Change and Human Activities in the Mekong River Basin

Bikesh ShresthaWater Engineering and Management,

School of Engineering and Technology, Asian Institute of Technology (AIT) Klong Luang, Pathumthani, Thailand

Supervisory Team: Shreedhar Maskey, Ann Van Griensven, Stefan Uhlenbrook (UNESCO-IHE)

Mukand S. Babel (AIT)

January 31, 2011

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1. Problem statement & research questions

Sediments are a key factor in many Mekong processes. Navigation, bank erosion, filling up reservoirs, aquatic and agricultural productions are all dependent in some extent on sediment processes. The sediment input from the Mekong to the Tonle Sap Lake is one of the key factors of the high productivity of the lake. The changes in sediment regime that will results from basin developments, especially the hydropower reservoirs, will affect the sedimentation and erosion processes in the downstream river channels and the connected floodplains, lakes, the delta and the coastal areas. The varying conditions and processes along the Mekong set high demands for sediment monitoring methodology and modeling to respond to the complexity of the system.

Climate variability and change has the potential to alter the water balance of river basins. Such alterations are expected to affect the hydrological characteristics of low-latitude flood pulse systems (Wassmann et al., 2004; Murray-Hudson et al., 2006). Hydrology plays its part by delivering mineral and nutrient rich alluvial sediments during the flood season that help to sustain this exceptional agricultural productivity (MRC, 2005). Changes in surface water runoff and sediment loads can greatly affect the river ecosystem and geomorphology. Changing sediment supply (e.g., by trapping in dams) can induce strong changes in channel form, loss of habitats, and damage to infrastructure There will be a change in the water discharge, sediment flux and river morphology due to both human intervention and climate variability. This study will focus on the impacts due to climate change and human activities against the baseline situation of the catchment so as to formulate the strategies for adaptation. The analysis of flow and sediment budget will help understand the physical processes operating in the catchment and plan for the adaptation to suit the likelihood future scenarios. The research would be able to answer four main questions:

(i) What will be the impact of climate change on sediment flux?(ii) What will be the impacts of human activities on sediment flux?

a. What will be the impact of land use changes on sediment?b. What will be the impact of water resources developments more

specifically hydropower and irrigation projects on sediment?c. What will be the impact of both the land use changes and water resources

developments on sediment?(iii) What will be the impact of both the climate change and human interventions

on sediment flux?(iv) What adaptation strategies are needed for likely future climate change and

anthropogenic disturbance?

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2. Objectives of the studyThe general objective of the study is to develop adaptive strategies for the Mekong River Basin from sediment transport perspective under climate change and human interventions. The specific objectives of the study are as follows:

a. To assess the impact of climate change on the sediment yield from the basin. b. To assess the impact of human interventions on the sediment yield from the basin. c. To evaluate the impact of both climate change and human activities on the

sediment yield from the basin. d. To develop adaptation strategies needed for likely future climate changes and

anthropogenic disturbances on sediment.

3. Study Area

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Figure 3.1 Proposed study area

Nam Ou River is the longest in the northern region of Lao PDR. It originates at Ban Lantoug Gnai Village near the Lao-China border and flow to the south. It has a total

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Nam Ou

Source: WWF.panda.org


length of 390 km to the confluent point with the Mekong River. The total drainage area is 25,000 km² covering Phongsaly province, one third of Uodomxay province, and one haft of Loang Prabang province. The annual discharge is 12.28 km³ which is 7% of the annual discharge contributed by Lao drainage area to Mekong River (Source: http://www.wepa-db.net/policies/state/laos/river.htm, accessed on January 27, 2011).

The basin has been proposed as the study area for the project because of following justifications:

Water resources developmentso Nam Ou, is the major tributary system, which could be developed to export power

to China and the hydrological response is perhaps the most natural and undisturbed in all the Lower Basin (MRC, 2005). Under 20-year hydropower development plan in tributaries by MRC a total of 4,661 MW is expected from Lao tributaries. Out of the above mentioned power about 21% is planned to be generated from Nam Ou with 7 cascade dams (See Annex C 1) with total live storage capacity of 1659.4 MCM (Hoanh et al., 2010). Also the irrigation area is planned to increase by 44.4 % annually in this area (Hoanh et al., 2010) (see Annex C 2).

Source of sedimento Studies by Roberts (2001) and MRC (2003) concluded that upper Mekong

contributes 50% of the total annual sediment load of the Lower Mekong River. Despite much soil erosion and higher sediment production in the upper Mekong, major contributing source area of sediment in the lower Mekong are located in northern Laos (Liu, 1998). The study area lies in northern Laos. Fuchs (2004) ranked different catchments in Lower Mekong Basin regarding risk of soil erosion, where the basin is among the high risk of soil erosion (See Annex C.3).

Data Availabilityo In order to have better model results the complete and reliable data is must. Both

stream discharge and sediment data to be used for calibration and validation purpose are available for the basins however, the completeness and reliability of which needs to be assessed and confirmed with MRC.

Also it necessary to evaluate the tributaries contributions of The Mekong in sediment perspective.

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4. MethodologyThe methodology to evaluate the impact of climate change and human interventions on sediment of the basin and to develop adaptation measures is shown in Figure 4.1.

Figure 4.1 Methodology to evaluate the impact on sediment of the basin and to develop adaptation measures.

The Soil and Water Assessment Tool (SWAT) model will be used for the study basin. SWAT is a river basin or watershed scale hydrologic and water quality model developed by Dr. Jeff Arnold for the USDA Agricultural Research Services (ARS) (Arnold et al., 1993). It was developed to evaluate the effect of land use management on water, sedimentation, and agricultural chemical yield in large complex watersheds which have heterogeneity in land use, soil and management conditions over a long period of time. It is a semi-distributed, physically based, computationally efficient, and continuous time

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Pre-processing Phase

Processing & run Phase


model. It is also capable of simulating a high level of spatial detail. SWAT model was used because it is physically based and simulates actual processes, originated from agricultural models, degree of software support available to users and possibility of carryout uncertainty and sensitivity analysis. Also SWAT has been validated in many regions of the world for a variety of applications in hydrologic as well as water quality studies (Jha et al., 2007). SWAT has also been validated to Lower Mekong River Basin by Ross et al. (2009).

Figure 4.2 presents the framework of scenario analysis to be used for the study. The frame work of Hoanh et al., (2010) is modified for the study purpose.

Figure 4.2 Framework of scenario analysis for impact of climate change and human activities.

Recent studies by MRC and WUP-FIN have downscaled the precipitation and temperature for present and future two Scenarios A2 & B2 from the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (IPCC SRES) as provided by the SEA START Regional Center and based on the ECHAM4 GCM from the Max Planck Institute for Meterology, Germany. These were downscaled to Mekong region using the PRECIS system. The PRECIS climate data has a resolution of 0.2 degree x 0.2 degree (equivalent to about 22 km x 22 km). Hoanh et al. (2010) has already adjusted the downscaled RCM to fit simulated data with observed data for 1985-2000 and future adjusted to the projected data for 2010-2050. The study has projected change of +1.86 mm/yr under A2 scenario and +0.98 mm/yr under B2 scenario in annual rainfall of

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Lower Mekong River Basin (LMB), while the annual temperature is expected to rise by +0.020 to +0.0230C/yr. The adjusted project PRECIS climate data for 2010-2050 will be collected from MRC for climate change scenario analysis of the study. The water resource development scenarios will be based on BPD 20-year plan.

5. Deliverables

The study results will be disseminated to concern authorities, scientific community and public through research reports, journal article and conference paper. The expected deliverables are presented in Table 5.1.

Table 5.1 Deliverables

S.N Intended Outputs 2010 2011

1 Research reports - 1

2 Articles for peer reviewed journals - 2

3 Other Academic Publications specify type: conf. pap. - 1

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6. Work Plan

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Literature Reviewed

Arnold, J.G., Allen, P.M., Bernhardt, G., (1993). A comprehensive surface-groundwater flow model. Journal of Hydrology 142, 47–69.

Arnold, J.G., Williams, J.R., and Maidment, D.R., (1995). Continuous-time water and sediment routing model for large basins, Journal of Hydraulic Engineering Vol. 121(2): pp. 171-183.

Fuchs, H.J., (2004). Data availability for studies on effects of land-cover changes on water yield, sediment and nutrients load at catchments of the Lower Mekong Basin. Working Paper 09. MRC-GTZ Cooperation Programme.

Hoanh, C.T, Jirayoot, K., Lacombe, G., Srinetr., (2010). Impact of climate change and development on Mekong flow regime. First assessment-2009. MRC Technical Paper No. 29. Mekong River Comission, Vientiane, Lao PDR.

Jha, M.K., Gassman, P.W., Arnold, J.G., (2007). Water quality modeling for the Raccoon river watershed using SWAT. American Society of Agricultural and Biological Engineers 50, 479–493.

Keskinen, M.,(2008). Water resources development and impact assessment in the Mekong Basin: Which way to go? Ambio 37:193-198.

Kummu M. and Varis O., (2007). Sedimentrelated impacts due to upstream reservoir trapping, the Lower Mekong River, Geomorphology, Elsevier, vol 85, No 34, pp.275-293.

Lu, H., (1998). Comparative analysis of the hydrological characteristics inLancang-Mekong River basin, International symposium of flooding in South Asia, Bangladesh.

Lu X. X. and Siew R.Y.,(2005). Water discharge and sediment flux changes in the Lower Mekong River, Journal of Hydrology and Earth System Sciences.

MRC (2003). MRC Work Programme 2003.

Mekong River Commission, (2005). Overview of the Hydrology of the Mekong Basin, Mekong River commission, Vientiane, November, 2005.

MRC (2009) Adaptation to climate change in the countries of the Lower Mekong Basin: Regional synthesis report. MRC Technical Paper No. 24. Mekong River Commission, Vientiane, Lao PDR. MRC. 2010. State of the Basin Report 2010. Mekong River Commission, Vientiane, Lao PDR.

MRC (2009). Supplement Note for 5th RTWG meeting on scenario formulation and assessment of hydrological changes. Internal Technical Note, Basin Development Plan Programme Phase 2. Mekong River Commission Secretariat, Vientiane, Lao PDR.

Murray-Hudson, M., Wolski, P. & Ringrose, S, (2006). Scenarios of the impact of local and upstream changes in climate and water use on hydro-ecology in the Okavango Delta, Botswana, Journal of Hydrology, 331 (1–2), 73–84.

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Roberts, T., (2005). Downstream ecological implications of China’s Lancang Hydropower and Mekong Navigation Project, International Rivers Network (IRN).

Rossi, C.G., Srinivasan, R., Jirayoot, K., Duc, T.Le, Souvannabouth, P., Binh, N., Gassman, P.W., (2009). Hydrologic evaluation of the lower Mekong river basin with the soil and water assessment tool model. International Agricultural Engineering Journal 18(1-2), 1-13.

Walling D. E., (2008). The Changing Sediment Load of the Mekong River, Royal Swedish Academy of Sciences, Vol. 37, No. 3, pp.150-157.

Wang, J.J., Lu, X.X., Kummu, M., (2009). Sediment Load Estiates and Variations in The lower Mekong River. River Research and Applications 27, 33-46.

Wassmann, R., Hien, N. X., Hoanh, C. T. & Tuong, T. P. (2004). Sea level rise affecting the Vietnamese Mekong delta: water elevation in the flood season and implications for rice production, Climate Change 66 (1–2), 89–107.

World Bank/Mekong, (2004). Modelled Observations on Development Scenarios in the Lower Mekong Basin, River Commission, Washington, DC/Vientaine, November 2004.

MRCS/WUP-FIN, (2007). Final Report – Part 2: Research findings and recommendations. WUP-FIN Phase 2–Hydrological, Environmental and Socio-Economic Modelling Tools for the Lower Mekong Basin Impact Assessment. Mekong River Commission and Finnish Environment Institute Consultancy Consortium, Vientiane, Lao PDR. 126 pp.

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Annex A: Logical Framework Description Main activities, results &

deliverablesPerformance Indicators

Critical assumptions / risks

Specific objective 1:Assess the impact of climate change on the sediment yield from the basin.

Model to be run with baseline scenario

Model to be run with future climate data

The outcome will be part of 1st journal paper/ Research report/conference paper

The results will be compared against baseline and future projection

The data and model are expected to be obtained from MRC.

For future climate PRECIS RCM with A2 & B2 scenarios to be used

Specific objective 2:Evaluate the impact of human interventions on the sediment yield from the basin.

First Phase: Model to be run with

landuse change scenarios Second Phase: Model to be run with future

water resources development plans

Third Phase: Model to be run with future

landuse changes and water resources development plans


The results will be compared against baseline and future changes


Water resources development plans to be based on BDP scenarios

Future landuse changes to be based on BDP scenarios

Specific objective 3: Evaluate the impact of both climate change and human activities on the sediment yield from the basin.

First Phase: Model to be run with

landuse change scenarios and climate change projections

Second Phase: Model to be run with future

water resources development plans and climate change projections

Third Phase: Model to be run with future

landuse changes, water resources development plans and climate change projections

The results will be compared against baseline and future changes


Water resources development plans to be based on BDP scenario

Future landuse changes to be based on BDP scenarios

For future climate PRECIS RCM with A2 & B2

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Description Main activities, results & deliverables

Performance Indicators

Critical assumptions / risks


scenarios to be used

Specific objective 4: Develop adaptation strategies needed for likely future climate changes and anthropogenic disturbances on sediment.

Model to be run with future landuse changes, water resources development plans and climate change projections with various adaptation measures

Expected outcome will be the appropriate adaptation measures that can be incorporated for proper sediment management in basin against future climate changes, and human activities.

The outcome will be part of 2nd Journal Paper/ Research report/conference paper

The results with adaptation to be compare against without adaptation

Different adaptation measures to be fed into the model will be based on literature and report

Answering all the four specific objectives will lead to the fulfilment of overall objective of the project that is to develop adaptive strategies for the Mekong River Basin on sediment under climate change and human intervention.

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Annex B: Estimated Research Budget

S.N Particulars Unit QuantityRate (Euro)

Total Amount (Euro)

1 Field Visit and Data Collection 2,900.00

a. MRC cambodia for model setup 1,650.00

Subsistence days 20 30 600.00

Hotel days 20 25 500.00

Air fare (Bangkok-Nomphen-Bangkok) times 1 400 400.00

Local transport 100 100.00

Visa Fee 50 50.00

b. Laos visit 1,250.00

Subsistence days 15 30 450.00

Hotel days 15 20 300.00

Air fare (Bangkok-Vientiane-Bangkok) times 1 350 350.00

Local transport 100 100.00

Visa Fee 50 50.00

2 Data buying 2,000.00

3 Communications and Stationaries 300.00

4 Conference and Workshops* 1,500.00

5 Computer and Accessories 1,500.00

6 Overhead 1,000.00

Total 9,200.00

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Annex C 1: Location of hydropower dams (Source: MRC, 2009)

Nam Ou

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Annex C 2a: Irrigation area (x 1000 ha) in Baseline and LMB-20 year plan (location of BDP sub areas is shown in Annex C2b) (Source: Hoanh et al., 2010)

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Annex C 2b Location of BDP sub- areas (Source: Hoanh et al., 2010)

Nam Ou

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Annex C 3 Ranking of catchment regarding risk of soil erosion (source: Fuchs, 2004)

Note: 1=Nam Ou basin; 2= Nam Ngum basin

Nam Ou

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