The Mekong River Basin in Southeast Asia is experiencing extensive hydropower development. Concerns have been raised about the consequences of the development for the ecosystems, livelihoods and food security in the region. The largest planned hydropower dam cascade in the basin, the Lancang-Jiang cascade, is currently under construction and already partly built into the Upper Mekong Basin, China. In this paper we assess the impact of the Lancang-Jiang cascade on downstream hydrology by using a combination of a hydrological model and a reservoir cascade optimization model. The hydrological changes were quantified in detail at the Chiang Saen gauging station in Thailand, the first gauge station downstream from the cascade, and in lesser detail at four other downstream locations in the Mekong mainstream. We found that on average the Lancang-Jiang cascade increased the December–May discharge by 34–155 % and decreased the July–September discharge by 29–36 % at Chiang Saen. Furthermore, the Lancang-Jiang cascade reduced (increased) the range of hydrological variability during the wet season (dry season) months. The dry season hydrological changes were significant also in all downstream gauging stations, even as far as Kratie in Cambodia. Thus the Mekong’s hydrological regime has been significantly altered by the Lancang-Jiang cascade, but what the consequences are for ecosystems and livelihoods, needs further study.
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Adamson P (2001) The Potential impacts of hydropower developments in Yunnan on the hydrology of the lower Mekong. International Water Power and Dam Construction 53:16–21
ADB (2004) Cumulative impact analysis and Nam Theun 2 contributions: Final report. Prepared by NORPLAN and EcoLao for Asian Development Bank (ADB).http://www.adb.org/Documents/Studies/Cumulative-Impact-Analysis/default.asp. Accessed 16 September 2010
ADB (2008) Lao People’s Democratic Republic: Preparing the Cumulative Impact Assessment for the Nam Ngum 3 hydropower project. Prepared by Vattenfall Power Consultant AB in association with Ramboll Natura AB and Earth Systems Lao for Asian Development Bank (ADB).http://www.adb.org/Documents/TARs/LAO/40514-LAO-TAR.pdf. Accessed January 2012
Bunn S, Arthington A (2002) Basic principles and ecological consequences of altered flow regimes for aquatic biodiversity. Environ Manag 30:492–507
Delgado J, Apel H, Merz B (2010) Flood trends and variability in the Mekong river. Hydrol Earth Syst Sci 14:407–418
Delgado J, Merz B, Apel H (2012) Climate-flood link for the lower Mekong River. http://www.hydrol-earth-syst-sci.net/16/1533/2012/. Hydrol Earth Syst Sci 16:1533–1541
Dingman S (2002) Physical hydrology, 2nd edn. Waveland Press, Illinois, 600
Driessen P, Decker J, Spaargaren O, Nachtergaele F (eds.) (2001) Lecture notes on the major soils of the world. Food and Agriculture Organization of United Nations (FAO)
Dugan P (2008) Mainstream dams as barriers to fish migration: international learning and implications for the Mekong. Catch Culture 14:9–15
Dugan P, Barlow C, Agostinho A et al (2010) Fish migration, dams, and loss of ecosystem services in the Mekong Basin. Ambio 39:344–348
FAO (2003) WRB map of world soil resources. Food and Agriculture Organization of United Nations (FAO), Land and Water Development Division.
GLC2000 (2003) Global Land Cover 2000 database. European Commission, Joint Research Centre
Grumbine R, Xu J (2011) Mekong hydropower development. Science 322:178–179
Grumbine R, Dore J, Xu J (2012) Mekong Hydropower: drivers of change and governance challenges. Front Ecol Environ 10:91–98
Hoanh C, Jirayoot K, Lacombe G, Srinetr V (2010) Impacts of climate change and development on the Mekong flow regime, First assessment - 2009. MRC Technical Paper No. 29 Mekong River Commission, Vientiane, Lao PDR.http://www.mrcmekong.org/assets/Publications/technical/tech-No29-impact-of-climate-change.pdf. Accessed January 2012
Hortle K (2007) Consumption and the yield of fish and other aquatic animals from the lower Mekong Basin. Mekong River Commission Technical Paper 16, Mekong River Commission, Vientiane. http://www.mrcmekong.org/assets/Publications/technical/tech-No16-consumption-n-yield-of-fish.pdf. Accessed January 2012
HydroChina (2010) Map of planned and existing hydropower projects. http://www.hydrochina.com.cn/zgsd/images/ziyuan_b.gif. Accessed 16 September 2010
ICEM (2010) MRC Strategic Environmental Assessment (SEA) of hydropower on the Mekong Mainstream. Hanoi, Viet Nam. http://www.mrcmekong.org/news-and-events/consultations/strategic-environmental-assessment-of-mainstream-dams. Accessed January 2012
Jarvis A, Reuter H, Nelson A, Guevara E (2008) Hole-filled SRTM for the globe Version 4. CGIAR-CSI SRTM 90 m Database
Johnston R, Kummu M (2012) Hydrological modelling in the Mekong Basin: a review. Water Resour Manag 26:429–455
Junk W, Wantzen K (2004) The flood pulse concept: New aspects, approaches and applications – An update. In: Welcomme R, Petr T (eds.) Proceeding of international symposium on the management of large river for fisheries. RAP Publications 2004716, FAO, Bangkok 2:117–140
Junk W, Bayley P, Sparks R (1989) The flood pulse concept in river-floodplain systems. In: Dodge D (ed.) Proceedings of the international large river symposium (LARS). Canadian Special Publication of Fisheries and Aquatic Sciences 106:110–127
Junk W, Brown M, Campbell I et al (2006) The comparative biodiversity of seven globally important wetlands: a synthesis. Aquat Sci 68:400–414
Keskinen M, Kummu M (2010) Impact assessment in the Mekong: review of strategic environmental assessment (SEA) & cumulative impact assessment (CIA). Water & Development Publications, Aalto University. TKK-WD-08. 48 p. http://www.wdrg.fi/publications/water-development-publications/impact-assessment-in-the-mekong. Accessed January 2012
Keskinen M, Chinvanno S, Kummu M, Nuorteva P, Snidvongs A, Varis O, Västilä K (2010) Climate change and water resources in the Lower Mekong River Basin: putting adaptation into the context. J Water Clim Change 1:103–117
Keskinen M, Kummu M, Käkönen M, Varis O (2012) Mekong at the crossroads: next steps for impact assessment of large dams. Ambio 41:319–324
Kingston D, Thompson J, Kite G (2011) Uncertainty in climate change projections of discharge for the Mekong River Basin. Hydrol Earth Syst Sci 15:1459–1471
Koponen J, Lauri H, Veijalainen N, Sarkkula J (2010) HBV and IWRM Watershed Modelling User Guide. MRC Information and Knowledge management Programme, DMS – Detailed Modelling Support for the MRC Project. http://www.eia.fi/index.php/support/download. Accessed January 2012
Kummu M (2008) Spatio-temporal scales of hydrological impact assessment in large river basins: the Mekong case. PhD Thesis, Water Resources Research Unit, Helsinki University of Technology. 92+ app. p 112
Kummu M, Sarkkula J (2008) Impact of Mekong River flow alteration on Tonle Sap flood pulse. Ambio 3:185–192
Kummu M, Varis O (2007) Sediment-related impacts due to upstream reservoir trapping, the Lower Mekong River. Geomorphology 85:275–293
Kummu M, Lu XX, Wang JJ, Varis O (2010) Basin-wide sediment trapping efficiency of emerging reservoirs along the Mekong. Geomorphology 119:181–197
Labadie J (2003) Generalized dynamic programming package: CSUDP. Documentation and user guide, version 2.44. http://modsim.engr.colostate.edu/csudp.shtml. Accessed January 2012
Labadie J (2004) Optimal operation of multireservoir systems: state of the art review. J Water Resour Plann Manag 130:93–11
Lamberts D (2008) Little impact, much damage: the consequences of Mekong River flow alterations for the Tonle Sap ecosystem. In: Kummu M, Keskinen M, Varis O (eds.) Modern myths of the Mekong. Water & Development Publications, Helsinki University of Technology, pp. 3–18
MRC (2005) Overview of the hydrology of the Mekong Basin. Mekong River Commission (MRC), Vientiane, Lao PDR
MRC (2009a) Economic, environmental and social impact assessment of basin-wide water resources development scenarios, Assessment methodology. Mekong River Commission (MRC) technical note, Vientiane Lao PDR. http://www.mrcmekong.org/assets/Other-Documents/BDP/Tech-Note2-Scenario-assessment-methodology-complete-Report091104.pdf. Accessed January 2012
MRC (2009b) Hydropower dam database. Mekong River Commission (MRC), Vientiane Lao PDR.
MRC (2009c) Mekong river basin 1:50’000 vector data. Mekong River Commission (MRC), Vientiane Lao PDR
MRC (2010) State of the basin report 2010. Mekong River Commission (MRC), Vientiane, Lao PDR. p 232
MRC (2011) Assessment of basin-wide development scenarios, Basin Development Plan Programme, Phase 2. Mekong River Commission (MRC), Vientiane, Lao PDR http://www.mrcmekong.org/assets/Other-Documents/BDP/Assessment-of-Basin-wide-dev-Scenarios-MainReport-110420.pdf. Accessed January 2012
MRCS/WUP-FIN (2003) Modelling Tonle Sap for environmental impact assessment and management support. Final report, WUP-FIN Phase I, Mekong River Commission and Finnish Environment Institute consultancy consortium, Phnom Penh. http://www.eia.fi/wup-fin/Reports/wup-fin1/WUP-FIN_FinalDraft.pdf. Accessed January 2012
NASA (2010) Tropical rainfall measuring mission (TRMM). NASA, Goddard Space Flight Center.
NCDC (2010) Global Surface Summary of the Day (GSOD). US National Climatic Data Center.
Nilsson C, Berggren K (2000) Alterations of riparian ecosystems caused by river regulation. BioScience 50:783–792
Nilsson C, Reidy C, Dynesius M, Revenge C (2005) Fragmentation and flow regulation of the world’s large river systems. Science 308:405–408
Peel M, Finlayson B, McMahon T (2007) Updated world map of the Köppen-Geiger climate classification. Hydrol Earth Syst Sci 11:1633–1644
Qiu J (2010) China drought highlights future climate threats. Nature 465:142–143
Rani D, Moreira M (2010) Simulation-optimization modeling: a survey and potential application in reservoir systems operation. Water Resour Manag 24:1107–1138
Sarkkula J, Keskinen M, Koponen J, Kummu M, Richey J, Varis O (2009) Hydropower in the Mekong region: what are the likely impacts upon fisheries? In: Molle F, Foran T, Käkönen M (eds) Contested waterscapes in the Mekong region - Hydropower, livelihoods and governance. Earthscan. pp. 227–249
Sarkkula J, Koponen J, Lauri H, Virtanen M (2010) IWRM modelling report. Detailed Modelling Support (DMS), Information and Knowledge Management Programme, Mekong River Commission. http://www.eia.fi/DMS/DMS_IWRM-Report_24December2010_v4.pdf Accessed January 2012.
Saxton K, Rawls W (2006) Soil water characteristic estimates by texture and organic matter for hydrological solutions. Soil Sci Soc Am J 70:1569–1578
Stone R (2010) Severe drought puts spotlight on Chinese dams. Science 327:1311
Stone R (2011) Mayhem in the Mekong. Science 333:814–818
Surian N (1999) Channel changes due to river regulation: the case of Piave River, Italy. Earth Surf Process Landforms 24:1135–1151
Västilä K, Kummu M, Sangmanee C, Chinvanno S (2010) Modelling climate change impacts on the flood pulse in the Lower Mekong floodplains. J Water Clim Change 1:67–86
World Bank (2004) Modelled observations on development scenarios in the Lower Mekong Basin, Mekong Regional Water Resources Assistance Strategy. Prepared for the World Bank with Mekong River Commission cooperation. p. 142. http://ns1.mrcmekong.org/download/free_download/LMB-Development-Scenarios.pdf. Accessed June 2012
WUP-FIN (2008) Hydrological, environmental and socio-economic,modelling tools for the Lower Mekong Basin impact assessment. WUP-FIN Phase II, Mekong River Commission and Finnish Environment Institute consultancy consortium, http://www.eia.fi/wup-fin/Reports/wup-fin2/wup-fin2_Model-Report.pdf. Accessed January 2012
Yi J, Labadie J, Stitt S (2003) Dynamic optimal unit commitment and loading in hydropower systems. J Water Resour Plann Manag 129:388–398
The authors would like to thank the Mekong River Commission for providing the discharge data for the study. The authors are grateful to Prof. Olli Varis, Dr. Marko Keskinen, Aura Salmivaara and Mirja Kattelus for their support. Timo Räsänen received funding from the RYM-TO Graduate School and Maa- ja Vesitekniikan Tuki ry. and Matti Kummu received funding from the postdoctoral funds of Aalto University. The research was also supported by Academy of Finland (project 133748).
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Räsänen, T.A., Koponen, J., Lauri, H. et al. Downstream Hydrological Impacts of Hydropower Development in the Upper Mekong Basin. Water Resour Manage 26, 3495–3513 (2012). https://doi.org/10.1007/s11269-012-0087-0
- Hydrological impact assessment
- Hydrological modelling
- Dynamic programming
- Hydropower operation
- The Mekong Basin