DEVELOPMENT OF RIVER RUNOFF MODEL WHICH CAN REPRODUCE SEASONAL FLUCTUATIONS AND GLOBAL ASSESSMENT OF WATER SCARCITY, USING THE MODEL

Abstract

We developed a new global river discharge model by merging existing methods and tuning parameters in the model for better reproduction of observed monthly river discharges. The developed model enabled us to estimate amount of renewable water resource witha spatially finer scale than the previous studies. After verifying the effect of the parameter tuning, we appliedthe developed model to the assessment of water scarcity. The regions judged to have high risk of water scarcityare Sahara desert, Arabian Peninsula, Indus river basin, the northern part ofChile and California Peninsula. Though the regions judged to have high risk of water scarcity were similar to the results of the previous studies, we additionally succeeded in depicting inhomogeneous distribution of water scarcity risk inside the river basins. Since the developed model estimates monthly renewable water resources, monthly variation of water scarcity can be also assessed.