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| Erosion of sodic slope under the condition of simulated rainfall |
| Xiao Juan1 , Yan Peng2，Lu Wenli3 |
| 1. College of Hydraulic Science and Engineering, Taiyuan University of Technology, 030024 ,Taiyuan；2. Faculty of Hydraulic and Civil Engineering, China Agricultural Universily, 100083, Beijing；3. College of Water Resources and Hydroelectric Power Engineering, Yunnan Agricultural University, 650201 , Kunming：China |
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Abstract A group of rainfall simulation tests were conducted to quantify the effects of slope and soil with different exchangeable sodium percentage (ESP) on the water infiltration and soil erosion. Three different soil slope degrees (5°, 15° ,25°) and two ESP levels of soils (2.4 and 25 ) in the same rainfall intensity (50 mm/h) were designed in this study. Results indicated that ： 1) For each treatment, runoff modulus increased rapidly at the beginning of rain, then arrived at a steady value over time, and soil infiltration rate and sediment yield decreased over rain duration； 2) In the same ESP level, soil infiltration rate and accumulated infiltration increased with the increase of slope degree. Soil erodibility increased with the increase of slope firstly, then decreased as the slope being 25°, which indicated that there was a critical erosion slope degree existing in the range of 15° -25°;3) In the same slope degree, runoff modulus increased with the increase of ESP of soil, while steady infiltration rate and accumulated infiltration decreased with the increase of ESP of soil ； 4) The effects of ESP levels of soil on soil erodibility changed with slope degree. Soil erodibility decreased with the increase of ESP level of soil under the slope of 5°and 15°, however, soil erodibility increased with the increase of ESP of soil under the slope of 25°. It is suggested that we should pay more attention to erosion of higher ESP level of soil at greater slopes ( > 15°).
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Received: 01 October 2010
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