Abstract
We estimated theoretical hydropower potential and its future change at the global scale under four climate change scenarios. River discharge was calculated with a global hydrological model, H08. Future bias-corrected meteorological data sets produced from five general circulation models were used as input meteorological data. The global theoretical hydropower potential for 1960-1989 was estimated 43,890TWh, and showed larger increasing trends under warmer climate scenarios. We also estimated hydropower generation from simulated seasonally-varying river discharge under an assumption of a plausible specification design of hydropower plants based on flow-duration curves. Estimated hydropower generation also showed increasing trends, similar to the theoretical hydropower potential, but its future change was smaller. Geographical distribution of future changes in the working efficiency of hydropower plants were similar to that of the theoretical hydropower potential, whereas geographical distribution of future changes in the efficiency of river water utilized for hydropower generation is far from that of the theoretical hydropower potential. Based on future changes of these two efficiencies, we classified global land regions into four and discussed the effects of future climate change on water resources and hydropower generation for each classification.
