Undermined co-benefits of hydropower and irrigation under climate change

Dam construction is mostly aimed for multiple functions, including irrigation water provision, hydropower, and some others that bring substantial social benefits. However, global warming impacts on the interaction of the positive outcomes of damming remain little known, particularly in terms of the sustainability of their co-benefits, whereby investigating the different impacts of global warming scenarios of 1.5 °C and 2 °C has been a hotspot in water resources and energy research worldwide. This study used an integrative analysis based on a hydrological, techno-economic and agricultural modeling framework to evaluate the effects of global warming scenarios of 1.5 °C and 2 °C on the co-benefits between hydropower and irrigation in the Mekong River basin. The results show the declined hydropower generation and irrigation water supply in the Mekong River basin under 1.5 °C and 2 °C warming scenarios. The co-benefits between the hydropower and the irrigation is more undermined by the global warming of 2 °C relative to 1.5 °C in the Mekong River basin. Moreover, the changes of co-benefits are sensitive to the consideration of the protected areas in the basin. With the consideration of the protected areas, the co-benefits would be enhanced by 2 °C global warming compared to 1.5 °C global warming. Therefore, it is critical for decision-makers to consider the tradeoffs between the environment and dam construction for ensuring energy and food security under global warming scenarios.