Decision support for preliminary release of reservoir for flood control using ECMWF medium-range ensemble rainfall forecast

Abstract

A method for integrated reservoir operation is developed by considering medium-range ensemble rainfall forecast provided by European Centre for Medium-Range Weather Forecasts (ECMWF) to enhance reservoir’s flood storage capability while maintaining its function for water use. Preliminary release operation, in which storage water for water use is released just before a flood occurs, is considered here. The desired timing and amount of preliminary release are estimated from ensemble prediction, maximizing the flood control capacity while securing storage recovery after the flood event. The case study with Shin-Nariwagawa Reservoir in the Takahashi River basin, Japan, demonstrated the effectiveness of introducing long-range ensemble prediction in decision making for preliminary release.