山地流域における出水と土砂流出 (9)

Abstract

Observational studies of the runoff process, sediment yield and transport have been carried outin a mountain basin, Ashiaraidani (7.2 Km2), which is a tributary of the Jintsu River in GifuPrefecture, Japan.In the Hirudani experimental basin, which is one small tributary in the Ashiaraidani, theprocess and mechanism of sediment transport on the stream channel with sequential falls andpools were considered by means of the petorological and grain-size classification of transportedgravels in reference to the geological distribution in the basin, and the relationships between flowrate and sediment discharge.In the Ashiaraidani experimental basin, transport of gravels on the channel during a floodwas investigated taking notice of the difference in the grain-size distributions in armoured bed anddebris flow deposits. The mechanism of occurrence and behavior of debris flow were analyzed bythe river bed variation before and after the passage of it and the concept of water balance.