内水管理用洪水流出モデルと実時問水位予測

Abstract

Two flood runoff models are developed to construct a real-time forecasting system for flood water level at a drainage pump station. One of them is a distributed form simplifying the diffusive tank model for analyzing flood water in a low-lying area. Another one is a lumped form composed of a retardation pond and two tanks for expressing flood runoff from urban and rural areas.The forecasting system is constructed by combining the Kalman filter technique and one of flood runoff models. The usefulness of this forecasting system is examined at the Ogura and Kumiyama pump stations situated at the outlet of the Ogura basin. The system is operated for two floods caused by heavy rainfalls in July 9 to 16, 1972, and in July 20 to 22, 1986.As a result, it is clarified that forecasting of water levels is performed with accuracy enough for practical use by either flood runoff model, and that the system using the lumped model has an enormous advantage of the reduction of computation time over the other system.