The purpose of this study is to clarify changes in surface runoff characteristics and sediment discharge on a granule ash-covered slope. Three years after the latest eruption of Unzen volcano, we made an observation of surface runoff and sediment discharge on a slope of the ash-covered treatment the following points were found. (1)It was considered that the volcanic ash covered on the study slope was washed away from the slope by surface runoff as suspended sediment. (2)The peak discharge and total amount of surface runoff after the treatment increased under the approximately similar rain conditions. (3)The decrease in the surface runoff and sediment discharge resulted from disappearance of the volcanic ash on the surface of the slope. It is concluded that the runoff characteristics of the study slope had changed with the covering and the movement of fine-grained volcanic ash.
細粒火山灰被覆を行った斜面の降雨流出に関する実験的研究
JJSECE55(5)_22-30.pdf
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