Potential water withdrawal reduction to mitigate riverine ecosystem degradation under hydropower development: A computable general equilibrium model analysis

摘要

Hydropower development can lead to riverine ecosystem degradation due to flow regime alteration, but also offers an opportunity to reduce water withdrawal from rivers for better maintenance of environmental flows, because hydropower could substitute for water to promote economic development, to some extent. Seizing this opportunity, this research proposes to adjust the water withdrawal volume at the national scale by reducing withdrawal from rivers with environmental flow deficits, and seeks to determine the volume of water withdrawal that could be reduced under the increase of hydropower generation. A computable general equilibrium model (CGE) is established to analyse the balance of water and hydropower from the perspective of economic development. China is adopted as a case study to demonstrate the effectiveness of the method. The results show that the water-hydropower equivalent decreases with the hydropower yield. When the hydropower yield increases by 10%, 30%, 100% and 150%, the water-hydropower equivalents are 0.73, 0.54, 0.22 and 0.13 m(3)/kWh, respectively, and the water compensation rate for hydropower increase is determined accordingly.