摘要
本文用多坡段组合模型代表黄土高原典型坡沟系统的各垂直分带,运用人工模拟降雨的实验方法,研究了坡沟系统土壤侵蚀链内各种侵蚀方式在时间和空间上的分布特征,结果表明:产沙过程呈现出多峰特点。雨强29.7mm/h时主要以面蚀为主,产沙起伏3次。雨强60.5mm/h时以面蚀与细沟蚀为主,伴有崩塌、滑塌等重力侵蚀过程。90.2mm/h时细沟发育充分,25°坡段细沟发育较多并出现浅沟现象,35°坡崩塌、滑塌剧烈。位置愈低的坡段产流量愈大,单位面积和时间的产流量按坡段排列为谷坡>梁峁坡下部>梁峁坡中部>梁峁坡上部。由于上坡来水的作用,梁峁坡的产沙量增大了20.2%～63.5%,谷坡的产沙量增大了42.9%～74.5%。有效控制上坡来水量和各坡段的产流量,坡面侵蚀产沙将会大幅度减少。
Temporal and spatial distribution characteristics of erosion in the soil erosion chain of slopegully system are studied by experimental approach of artificially simulated rainfall, and the composite model with sections of different grades, which is representative of vertical belts of typical slopegully system on Loess Plateau, is adopted in the experiment. Results show: the process of sediment production is characteristic of peaks. When the rainfall density is 29.7mm/h, the erosion is primarily the surface erosion and there are three fluctuations in the process of sediment production. When the rainfall density is 60.5mm/h, the surface erosion and the rill erosion are the main erosion types, attended by gravity erosion, such as landslip and slippery collapse etc. When the rainfall density is 90.2mm/h, the rills develop fully, some rills begin to converge and shallow gullies appears on the down section of 25°, and severe landslip and slippery collapse occur on the slope section of 35°. The lower is the slope section, the greater is the runoff amount formed on it. The runoff yield per unit area and per unit time on various slope sections is arranged in the following order: the gully slope>the lower hill slope>the middle hill slope>the upper hill slope. Because of the runoff from upper slope, the sediment yield on the replatgirder slope increases by 20.2%～63.5% and that on the gully slope grows by 42.9%～74.5%. If the runoff from upper slope and the runoff yield can be controlled effectively, the sediment produced by erosion will be reduced substantially.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2003年第5期540-546,共7页
Chinese Journal of Hydrodynamics
基金
国家973计划项目(2002CB111502)
中国科学院知识创新工程项目(KZCX1 10 04)
国家自然科学基金资助项目(49671052)
黄土高原土壤侵蚀与旱地农业国家重点实验室重点基金(10501 78)。
