水科学进展2016，Vol.27Issue(2)：224-230,7.DOI:10.14042/j.cnki.32.1309.2016.02.007
植被作用下土壤抗剪强度和径流侵蚀力的耦合效应
Effects of soil shear strength and runoff erosivity on slopes with different vegetation cover
摘要
Abstract
The combined effects of soil shear strength and runoff erosivity is important to quantitatively express the re-lationship between soil erosion resistance ability, runoff detachment, and transport capacity. We used field data and simulated rainfall experiments to study the effects of grass and shrub cover on runoff and sediment yield and its me-chanical mechanism. Based on standard field plots data, runoff reduction on grass and shrub plots decreased by 28. 1%—56. 5% and 85. 7%—100%, respectively, and sediment reduction on grass and shrub slopes decreased by 84. 9%—90. 7% and 98. 5%—100%, respectively, compared with the bare plot. Under simulated rainfall intensities of 45, 87 mm/h and 127 mm/h on a 20° slope gradient, runoff reduction on grass and shrub slopes decreased by 51. 9%—90. 9% and 61. 7%—80. 6%, respectively, and sediment reduction on grass and shrub slopes decreased by 93. 6%—99. 2% and 95. 5%—99. 2%, respectively, compared with the bare slope. Vegetation can enhance soil shear strength. Soil shear strength was proportional to the vertical pressure on the shear surface, and it was consistent with Coulomb′s law of shear strength. Soil cohesive force was negatively correlated with runoff as well as sediment yield. Runoff and sediment yield decreased with the increase in soil cohesive force. Sediment yield increased with the in-crease of flow shear stress, and there was a significant linear relationship between the two. The critical flow shear stresses of the grass slope and the shrub slope, respectively, were 2. 64—3. 16 times and 2. 44—3. 18 times that of the bare slope. The sediment transportation rate had a linear relationship with the flow shear stress. The critical flow shear stress and soil shear strength and the critical flow shear stress and soil cohesive force were significantly correla-ted. These relationships illustrate the mechanical effects of the soil erosion process. The results are useful for quantif-ying runoff and sediment reduction and understanding the mechanical process of soil erosion.关键词
土壤侵蚀/抗剪强度/黏聚力/径流切应力/草被/灌木Key words
soil erosion/soil shear strength/soil cohesive force/flow shear stress/grass/shrub分类
农业科技引用本文复制引用
肖培青,姚文艺,王国庆,杨春霞,申震洲..植被作用下土壤抗剪强度和径流侵蚀力的耦合效应[J].水科学进展,2016,27(2):224-230,7.基金项目
国家自然科学基金资助项目（41571276）；河南省创新型科技人才队伍建设工程（162101510004） The study is financially supported by the National Natural Science Foundation of China （ No．41571276）． （）
