RATES OF SLOPE DECLINE,TALUS GROWTH AND CLIFF RETREAT ALONG THE SHOMYO RIVER IN CENTRAL JAPAN: A SPACE‐TIME SUBSTITUTION APPROACH |
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| Authors: | HIROYUKI OBANAWA YUICHI S. HAYAKAWA YUKINORI MATSUKURA |
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| Affiliation: | 1. Department of Environment Systems, Graduate School of Frontier Sciences, The University of Tokyo, Japan;2. Geoenvironmental Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan |
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| Abstract: | On the basis of a space–time substitution, rates of cliff retreat and talus development overthe pasttens ofthousands of years were quantified for valley‐side slopes along the Shomyo River with a known rate of waterfall recession. Detailed profiles of the valley‐side slopes were obtained at 19 sites along the river by map reading and field survey, and the morphologic characteristics of the slopes were then measured. By combining the locations of the slopes with the recession rate of Shomyo Falls, it is estimated that the growth rate of the talus slope is 3.9–7.2 mm/yr, the rate of decline of the cliff is 2.0–4.0 × 10?4 deg/yr, and the retreat rate of the cliff top is 6.2–11.6 mm/yr. |
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| Keywords: | cliff talus slope angle growth rate retreat rate space– time substitution |
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