CONSTRUCTION OF FLOOD RUNOFF MODEL UTILIZING RAINFALL FORECASTS FROM JMA

Abstract

Real-time flood forecasting needs accurate rainfall forecast, because Japanese river basins have a small area and steep topography that cause rapid rainfall-runoff. This paper aims to improve the accuracy of flood forecasting, considering recent advancement of short-term rainfall forecasts provided from the Japan Meteorological Agency (JMA). The method proposed here is to combine predictions by the Meso Scale Model with other predictions such as the Precipitation Nowcast and the Very Short Range Forecast. The results of its application to the Okawa River basin in Miyagi Prefecture indicate improvement in flood forecasting accuracy. Since this method is easy-to-use and effective, it would be useful for the improvement of flood forecasting in other river basins in Japan.