Flood Management in Urban River Basins

A flood management system used for urban rivers in Japan is presented in this paper. The system is composed of three subsystems: on-line data collection subsystem which is used for collecting rainfall and water level data; flood prediction subsystem based on the previous 3-hour hydrologic data; and result display subsystem. The on-line data collection subsystem is used to collect necessary rainfall and water level data for flood prediction in short periods of 10 minutes. The flood prediction subsystem is composed of effective rainfall estimation, slope flow model, and channel flow model, which integrates the effect of land use, rainfall intensity, and the drainage facilities in the river basin. The purpose of the display subsystem is to provide necessary hydrologic data for all users, which is developed with the combination of the WWW (World Wide Web) explorer and may be linked with the Internet. This system was developed in 1998 and was used for practical flood prediction later. The functionalities of every subsystem were tested and the more efficient application will be expected.