Recent progress in Japanese studies on storm runoff processes

Abstract

Recent Japanese studies on storm runoff processes in forested drainage basins showed the important role of subsurface water, especially groundwater flow during storm events. It was recognized that several mechanisms such as rapid flow through soil pipes, capillary water effect, air pressure effect and capillary barrier effect operate inducing a rapid response of groundwater to storm events depending on differences in local hydrologic conditions. All of these mechanisms were chiefly attributed to inhomogeneities and hydraulic property differences of the soil deposits. Interactions between storm runoff processes and geomorphic processes were also investigated.