Abstract
The evaluation of soil moisture content is important in forecasting flood and landslide disasters. The authors previously proposed a method for estimating soil moisture content on the basin scale based on a tank model; however, determining model parameters from the observed values has been a problem to be solved in generalizing the proposed method. In this study, determination of parameters from geological information was attempted. First, the rainfall, snowmelt and evapotranspiration of the Ishikari River basin were estimated. Next, a relational expression between the parameters of the basins of tributaries and the geologic surface area ratio was obtained, and the discharge of the Ishikari River basin was simulated based on the relational expression. As a result of the simulation, the method for determining parameters based on the geologic surface area ratio was thought to be useful in generalizing the evaluation method for basin-scale soil moisture content.
