Experiment on effect ofrock fragment cover on slope erodibility of saline-sodic soil in costal reclamation area
WANG Hongde1,2, XU Xiaoming3, SHE Dongli1,2
1. Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment in Southern China, Ministry of Education, Hohai University, Nanjing, Jiangsu 210098, China; 2. College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, Jiangsu 210098, China; 3. Liyang Bieqiao Water Conservancy Station, Liyang, Jiangsu 213300, China
Abstract The effects of rock fragments cover(RC)on the saline-sodic soil erosion and the interrill erodibility were investigated through simulated rainfall with two intensities(92 mm/h, 119 mm/h), two slope gradients(15%, 30%), and six rock fragments covers(0%, 10%, 20%, 40%, 60% and 80%). Results showed that with the increase of cumulative rainfall, the soil erodibility increased first, then decreased and tended to be stable. The soil erodibility was significantly increased with slope gra-dient. The soil erodibility varied non-monotonically with RC. In the condition of deeper slope and lower RC, soil erodibility increased with RC; while infiltration rate increased, runoff rate and soil erodibility decreased with RC when RC was higher. The appropriate RC could change the roughness of slope surface and reduce the soil erodibility. A significant negative linear correlation existed between Reynolds number of runoff and soil erodibility on the slope with rock fragments cover. Quantitative analysis of li-near relationship between Reynolds number and soil erodibility can reflect hydrodynamics process of saline-sodic soil on slope surface, which is of significance to building a prediction model of sediment transport in saline-sodic soil slope.
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