Dam-Impacted Water-Energy-Food Nexus in Lancang-Mekong River Basin

Dams heavily impact the Lancang-Mekong River, leading to water-use conflicts for hydropower, food production, and ecosystem sustainment. Basin-scale cooperation has been shown to yield incremental benefits; however, understanding of the water-energy-food (WEF) nexus-critical for cooperation and benefit-sharing in transboundary basins-is insufficient. A WEF nexus model for the Lancang-Mekong River Basin (LMRB) was developed to investigate the impacts of value preferences from riparian countries, reservoir operation policies, and future dam construction. The analysis shows that the value preferences for hydropower and agriculture significantly influenced the WEF nexus under cooperation. If downstream countries preferred rice production (RP), there was a substantial reduction in hydropower generation (HP) to meet the irrigation demands of RP because reservoirs operate for basin-level optimization under cooperation. Ecological water demands in China and downstream countries are represented by environmental flow constraints and competed with potential HP and potential RP at the basin scale, whereas trade-off relationships among the WEF nexus depended on hydrology. HP and RP benefited from river damming in downstream countries, considering better dam regulation of streamflow. The complex relationships among the WEF nexus highlight the importance of flexible cooperation policies considering various sociohydro conditions in the LMRB; thus, this study's results can offer real-world preferences.

Automated summary

The study shows that the value preferences of riparian countries, reservoir operation policies, and future dam construction significantly impact the water-energy-food nexus in the Lancang-Mekong River Basin. There are complex trade-off relationships among hydropower, agriculture, and ecological water demands at the basin scale, emphasizing the importance of flexible cooperation policies considering sociohydro conditions in the LMRB.