Hydrological Simulation on a Mountain Heavy Snowfall Basin, Japan

Hydrological simulations in river basin scale generally use data obtained from ground based meteorological stations. The distribution and density of meteorological stations affect the accuracy of such hydrological modeling, especially for high mountainous river basins. However, Japan is a mountainous country and most meteorological stations are located in valley bottoms or other flat areas. In this study, we conducted a numerical investigation of river discharge by downscaling data derived from a regional climate model in 1.5-km resolution, instead of using station data. The Okutadami basin, a source area of the Agano River was selected and river discharge was reproduced from August 2005 to July 2006. The result showed that seasonal variation of river discharge could be represented and that discharge was generally underestimated compared with observed one.