HYDROLOGIC IMPACTS OF UPSTREAM DAMS ON THE MEKONG DELTA

You may be interested in a new analysis of the effects of recently completed Xayaboury Dam (on the Mekong mainstem near Luang Prabang) and a cascade of dams upstream in China on flow patterns in the Lower Mekong River. The paper, Mekong River, Xayaboury Dam, and Mekong Delta in the first half dry season 2019-2020 by Nguyen Ngoc Tran was published in Vietnamese in TIA SANG, a scientific journal published by the Ministry of Science and Technology. The English version is now available here. As illustrated in excerpts of Figures 5 and 6 from the paper, the hydrologic analysis shows that flows this dry season have been significantly lower than in prior years’ dry seasons.

Riverlab members have contributed scientific papers on the cumulative effects of upstream dams on the sediment budget of the Mekong Delta and other threats to the sustainability of the Delta (Kondolf et al 2014, Kondolf et al 2018) and the potential for strategic dam planning to minimize impacts of dams on downstream sediment budgets and fish migration (Schmitt et al 2019).


Water levels in the Mekong River at Nakhon Phanom reflecting severe drought conditions in the current dry season of the 2019-2020 water year. (Source: Nguyen Ngoc Tran. 2020, Mekong River, Xayaboury Dam, and Mekong Delta in the first half dry season 2019-2020, Figure 5.)


View of the exposed bed of the Mekong River at Nakhon Phanom in late October 2019, reflecting severe drought conditions in this year’s dry season. (Source: Nguyen Ngoc Tran. 2020, Mekong River, Xayaboury Dam, and Mekong Delta in the first half dry season 2019-2020, Figure 6.)

References Cited

Kondolf, G.M., Z.K. Rubin, J.T. Minear. 2014. Dams on the Mekong: Cumulative sediment starvation.  Water Resources Research 50, doi:10.1002/2013WR014651. >>link to paper

Kondolf, GM, RJP Schmitt, P Carling, S Darby, M Arias, S Bizzi, A Castelletti, T Cochrane, S Gibson, M Kummu, C Oeurng, Z Rubin, and T Wild. 2018. Changing sediment budget of the Mekong: Cumulative threats and management strategies for a large river basin. Science of the Total Environment 625: 114-134. https://doi.org/10.1016/j.scitotenv.2017.11.361 >>link to paper

Schmitt, R, S Bizzi, AF Castelletti, J Opperman, GM Kondolf. 2019. Planning dam portfolios for low sediment trapping shows limits on sustainable hydropower in the Mekong. Science Advances 5: eaaw2175 >>link to paper