Author(s): Yohei Amai; Daisuke Nohara; Tomoharu Hori
Keywords: Flood; Reservoir operation; Prior release; Real-time hydrological prediction; Accuracy assessment
Abstract: A method to assess flood control operation of a multipurpose reservoir considering real-time hydrological prediction is developed for more adaptive water resources management under climate change. Prior release operation, in which water is released from a reservoir precedential to arrival of floods to secure empty storage volume enough to store excessive flood water in the reservoir, is focused. Statistical characteristics in accuracy of operational inflow forecast, which is derived from rainfall forecast provided by Meso-scale Model of Japan Meteorology Agency, are investigated. A number of inflow predictions are then artificially generated simulating the characteristics of the inflow prediction based on the results of the statistical analysis on accuracy of inflow prediction so as to supplement scarcity in real prediction data. Monte Carlo simulations of the prior release operation are conducted considering the generated inflow predictions in order to statistically assess the effects and impacts of the prior release operation by a reservoir. The proposed method was applied to Kamafusa Reservoir in the Natori River Basin, Japan, clarifying a better policy to conduct prior release, considering both the effects in flood management as well as potential risks in water utilization after a flood event ended.