Distributed Hydrological Model for Fuji River Basin

Abstract

A distributed hydrological model is developed and applied to the Fuji River basin of 3,432 km2 in Japan, which is divided into squared meshes of 1-km resolution. Mesh meteorological data of temperature, wind speed, sunshine, precipitation, cloud amount, and humidity are produced from weather stations and geographic information system data by a stepwise regression method that characterizes relationships between meteorology and geography. This method provides spatially allocated daily input data. Then a comparatively simple distributed model is proposed, with a submodel of soil-vegetation-atmosphere-transfer type for any mesh and a conceptual submodel for river routing. Spatial distribution patterns and mesh-specific values of model parameters are calibrated with a geographic information system database and 3 years of meteorologic-hydrologic observations. The daily run model can simulate approximately daily processes of snow accumulation and melting, interception, evapotranspiration, and runoff components, which gives relatively good reproduction of annual water yield. The hourly run model version can simulate well hourly hydrograph in the rainy season, improving the daily model.