Experimental study on the development of mountains and critical slopes

2017 Fiscal Year Final Research Report

• Project/Area Number: 26350405
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geography
• Research Institution: Chuo University
• Principal Investigator: Ouchi Shunji 中央大学, 理工学部, 教授 (00185191)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 地形発達実験 / 隆起 / 人工降雨 / 流水侵食 / 斜面プロセス / 斜面崩壊 / 平衡高度

Outline of Final Research Achievements

Applying rainfall on a rising flat surface made of a mixture of fine sand and kaolinite induces valley development from edges. As valleys incise, slopes grow and slope failures start to occur. Material yielded by slope failures is quickly drained out by stream flows, and this reduces the rising rate of average height. Increasing frequency and size of slope failures leads the landform to the stage of steady state, in which erosion balances with uplift to keep average height around a certain level. High rainfall promotes fluvial erosion and restrains the surface rising in earlier stages, resulting in lower steady state height. When the permeability of sand mound is reduced, however, lower rainfall makes the steady state height lower, because high permeability intensifies slope processes. A change in a controlling factor draws different response from each element of erosion, namely, stream flow, slope processes and slope failures, to make the development of landform very complex.

Free Research Field

地形学