摘要
沟坡是黄土丘陵沟壑区小流域侵蚀产沙的主要来源,其侵蚀规律的研究可为流域水土保持措施优化配置提供科学依据,对该地区的防灾减灾和可持续发展具有重要现实意义。在多种坡度、坡高的陡坡模型上进行了模拟降雨试验,分别采用地貌仪和径流泥沙采样装置对次降雨过程中沟坡的重力侵蚀量和产流、产沙过程进行了动态监测和定量分析。结果表明:重力侵蚀在高含沙水流的形成中起着十分重要的作用,但不是每次重力侵蚀的发生都能导致高含沙水流;次降雨过程中,含沙量和输沙率均随降雨历时呈现上升趋势,特别是次降雨的中后期,含沙量和输沙率的增大趋势都比较明显;历次降雨事件中,次降雨30min全过程出口径流的平均产沙量和次降雨中后期出口径流平均产沙量的变化趋势一致;次降雨过程中,出口径流含沙量与输沙率随坡度的增大呈整体波动式增大,但与坡高关系不显著。总之,在黄土沟坡区,重力侵蚀对产沙过程有显著影响。
In the small watershed of the Loess Ravine Region, the highest soil loss normally occurs at the gully. Hence erosion of the gully is important for conservation practice allocation, disaster prevention and mitigation, and sustainable development in this area. Experiments with models of different slope gradients and slope heights were carried out under the simulated rainfalls, and the amount of soil and water loss was quantitatively analyzed in this study. The results were as follows： l） the gravitational erosion played an important role in the hyperconcentrated flows, although not all mass failure could lead to hyperconcentrated flows; 2） the sediment concentration and the sediment transport rate increased with the rainfall duration, especially in the later rainfall events; 3） for the outlet runoff in different rainfall events, the variation trend of the average soil content of the whole rainfall event was consistent to that of the later stage of the event; 4） the sediment concentration and the sediment transport rate increased with the slope gradient, but had no correlation with the slope height. Consequently gravity erosion has an important effect on the process of soil loss from the gully in the Loess Ravine Region.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2012年第12期140-145,共6页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目"黄土沟坡重力侵蚀过程试验模拟研究"(51079016
51179021)
中央高校基本科研业务费专项基金资助项目(DUT10RW314)联合资助
关键词
泥沙
降雨
侵蚀
重力
沟坡
高含沙水流
sediment, rainfall, erosion, gravitation, gully, hyperconcentrated flow
