林道からの土砂(特に浮遊砂)流出に関する室内実験

概要

論文の詳細を見る
In order to clarify the characteristics of sediment discharge from forest road by rainfall and overland flow, some experiments on slope erosion were carried out using simulated rainfall. In these experiments, we investigated the characteristics of suspended sediment discharge and soil erosion on forest road surface under the condition of constant rainfall intensity : 30, 60 and 90 mm/hr. As a result, some experiments show that the peak of suspended sediment concentration (SSC) precedes the peak runoff. In the case of 2, 4 and 15 degrees of slope gradient, the SSC decreases rapidly after the peak of SSC. While in the case of 8 degrees, SSC increases rapidly and keeps the maximum value with a certain degree of change. It is considered that the overland flow reaches critical tractive force nearby 8 degrees. Further, sediment yield and/or volume of suspended sediment become significant level when the slope gradient is over 8 degrees, so it is ascertained that the standard limit of longitudinal slope is 8 degrees for forest road construction.
日本雨水資源化システム学会の論文