黄土高原沟坡重力侵蚀的理论模型

Mechanical Model for Gravitational Erosion in Gully Area

重力侵蚀是黄土沟壑区土壤侵蚀的重要组成部分,其发生条件及侵蚀量受多种因素制约且具有一定随机性.本文通过运用水力学、土力学等力学方法对重力侵蚀主要影响因素进行分析,建立起沟坡重力侵蚀的概化力学模型,同时运用模糊及概率分析等数学方法将黄土沟坡的稳定问题转化为失稳概率,作为沟坡崩塌发生的预报条件,从而实现了考虑沟谷水流侧向切割,降雨入渗影响下的重力侵蚀模拟,为在黄土高原沟壑区进行水沙计算提供了基本方法.

erosion is the essential part of erosion types on loess plateau. Its quantity and trigger condition are subject to many factors. Furthermore, the factors themselves are also random variables. In this paper, methods of hydraulics and soil mechanics are applied to analyze relationship between stability and its factors, and an ideal model of gravitational erosion on gully region is obtained. In the model, fuzzy probability method is used to convert the result of mechanical analysis to collapse probability, and the probability can act as the forecasting condition. Therefore, the model, which refers to lateral erosion by the flow and influence of water content on soil cohesive strengthen, can provide basic methods for erosion simulation in loess plateau area.