摘要
重力侵蚀是土壤侵蚀的主要形式之一.在黄土高原地区,重力侵蚀对土壤侵蚀总量、高含沙水流特性和水沙过程的尺度现象等都具有重要贡献.但由于重力侵蚀机理复杂、发生随机性强以及缺乏直接观测资料,对重力侵蚀过程的模拟研究一直是土壤侵蚀领域的薄弱环节.笔者将一个基于土体失稳的沟坡重力侵蚀理论模型在数字流域模型框架下与坡面降雨径流和土壤侵蚀模型、沟道不平衡输沙模型耦合集成,并解决了重力侵蚀模型在流域中应用的一些具体问题,使重力侵蚀模型能够根据沟坡的几何形态、黄土的力学特性、降雨导致的土体含水量及力学性质变化、沟道水流对沟坡的淘刷等物理因素的影响,合理模拟流域中的重力侵蚀过程.将模型系统应用于岔巴沟流域和无定河流域,得到了重力侵蚀的分布及其占总侵蚀量的比例,模拟结果基本可信.
Gravitational erosion is one of the main forms of soil erosion. On the Loess Plateau in China, gravitational erosion effectively contributes to the total amount of soil erosion, the characteristics of hyper-concentrated sediment-laden flow and scale phenomena of sediment processes. However, gravitational erosion happens randomly with complex mechanism, and in-situ measurements are absent, thus simulation of gravitational erosion is still a weak point in soil erosion research. After solving a few application problems of gravitational erosion model in river basins, a theoretical model for gravitational erosion based on soil destabilization was integrated with rainfall-runoff-soil erosion model for hillslope and non-equilibrium sediment transport model for channel in the digital watershed model. Thus, the gravitational erosion model can appropriately simulate gravitational erosion processes in river basins according to the shape of gullies and its variation caused by channel flow wash, and the mechanical property of loess and its variation with moisture content caused by rainfall. The integrated model system was applied in Chabagou watershed and Wuding river basin. Results of distribution of gravitational erosion and its proportion in total soil erosion were proved reasonable .
出处
《天津大学学报》
EI
CAS
CSCD
北大核心
2008年第9期1136-1141,共6页
Journal of Tianjin University(Science and Technology)
基金
国家自然科学创新群体科学基金资助项目(50221903)
水利部黄河泥沙重点实验室2007年度开放课题基金资助项目(2007003)
关键词
重力侵蚀
数值模拟
黄土沟壑区
gravitational erosion
simulation
Loess Plateau
