Journal of the Japan Society of Erosion Control Engineering,
Vol.57,No.1,p.3-12,2004
Sediment discharge by sheet erosion and the effects of revegetation
on the flank of Sakurajima volcano
Yukiyoshi TERAMOTO, Etsuro SHIMOKAWA, Makoto TANAKA, Takashi JITOUSONO, Takahiro INAMOTO
Abstract
Sediment discharge by sheet erosion has been measured at Sakurajima volcano on slopes made up of bare land and revegetation. Characteristics of sediment discharge and the effects of revegetation on sediment discharge have been examined. The results are as follows. The yearly specific sediment discharge on revegetated slopes was about 2%for those on bare land slope. In cases where rainfall intensities were of the same degree, the values for the median diameter of the sediment discharge on revegetated slopes were about 50%of those on bare land slope. The infiltration capacity, Manning's coefficient of roughness, and the dry density of soil in the surface layer have been increased by incremental plant cover. Moreover, results of analyses using a runoff model and a sediment discharge formula shows that revegetation caused a decrease of the area contributing to the occurrence of Hortonian overland flow.
Key words:Sakurajima volcano, sheet erosion, sediment discharge, revegetation
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