An assessment for effects of forest soil on the storm runoff responses by an application of vertical unsaturated flow model - Observational results from Tounosu study catchment in Okazaki City -

Abstract

　A hydrological observation was conducted in a small mountainous headwater catchment located in Kitaharayama, Tounosu-cho, Okazaki City, Japan, and effects of forest soil on the storm runoff responses were examined based on the observational data. The observed storm runoff responses were successfully simulated by numerical simulation results using the vertical unsaturated flow model. Storm-runoff mitigation effects were larger for a crumb-structure soil than for a massive structure soil, and the effects increased as the soil-layer depth increased. Consequently, these results showed that the conservation of forest soil was important for our sustainable forest management.