Studies on the Hydro-Geomorphological Clasisfication and It's Quantification of Controlling Factors for Water Cycle in the Mountain Regions With Small Reliefs

自1989年以来，我们开展了水文地貌观测，以弄清小地貌山区水循环的控制因素。对于花岗岩山区的实验分水岭，我们选择了爱知东京大学森林的赤松分水岭和小原村的小原分水岭。为了与其他地质区域的流域进行比较，我们选择了爱知东京大学森林中被河流扇沉积的砂砾覆盖的犬山流域。这一年，我们重点研究了包括凋落物在内的表层作为暴雨流的集中流动路径。为了弄清这一层在水系径流形成中的作用，在赤松和犬山实验流域进行了观测，并对其导水率和持水特性进行了室内试验。虽然我们没有观察到枯枝落叶层和表层风化土壤中的地下水流，但证实了暴雨过程中表层土壤中出现了饱和贯通流。

Since 1989, we have carried out the observations on hydro-geomorphology to make clear the controlling factors of water cycle in the mountain regions with small reliefs. As for the experimental watershed in cases of granitic mountain region, we chose the Akatsu watershed in the Aichi Tokyo University Forests and Obara watershed in Obara Village. To compare with those watershed to another geologic area, we settled the Inuyama watershed in the Aichi Tokyo University Forests, which is covered by sand and gravel of fluvial fan deposit.In this year, we focused on the surface layer including, litter as concentrated flow path of storm flow. To make clear the role of such layer to the stream flow generation, observations in the Akatsu and Inuyama experimental watershed and laboratory experiments on those characteristics of hydraulic conductivity and water retention were carried out.From laboratory experiments, it was clear that saturated subsurface flow occurred through the litter layer overlying weathered soil. Although we could not observe subsurface water flows in both layers of litter and surface weathered soil distinctively, it was confirmed that saturated throughflow in the surface soil layer occurred during the storm event.