Erodibility of Soil at the Gully Head in Yuanmou Dry-hot Valley, China

摘要

In the recent years, gully erosion attracted increasing attention from scientists. However, there were few studies on the soilrnerodibility/anti-erodibilty for the gully erosion. Based on the principle of geotechnical slaking test, a new set of test apparatus had been designed and applied on the study of erodibility of soil at the gully head. In this experiment, 6 typical gully heads had been chosen. Soil at the different depth of each gully head had been sampled by the foil sampler and tested the slaking rate of them. Moreover, shear strength of soil at different depth of each gully head had been tested in situ.The results showed that gullies developed on the stratified soil or homogeneous soil have different morphological characteristics. At the sharp gully head, the erodibility of underlying soil was lower than the overlying soil's. Contrarily, at gradual gully head, the erodibility of underlying soil was not lower than the overlying soil's. Moreover, slaking rate of most gullies' soil in the study area is an inverse proportion to the shear stress. Thus, slaking rate and in-situ shear stress, any of them can be the indicator of the erodibility of soil in the study region. But shear stress is easier to measure in situ.