黄绵土坡面细沟侵蚀剥蚀能力试验

为研究黄土坡面细沟侵蚀规律,探究水流剥蚀能力的室内测算方法,以黄绵土为研究对象,设置2,4,6,8 L/min 4个流量,5°,10°,15°,20°4个坡度,土槽长度为12 m,进行室内径流冲刷试验,得到黄绵土坡面细沟侵蚀的临界沟长和输沙能力,基于二者之间的函数关系,推导出剥蚀能力的计算公式,以此研究不同试验条件下临界沟长、输沙能力和剥蚀能力的变化规律,并验证方法的准确性。结果表明：在设计水力工况条件下,黄绵土坡面细沟侵蚀的临界沟长的变化范围在5.33～11.12 m,且临界沟长随流量和坡度的增加而缩短;输沙能力随流量和坡度的增大而增大;剥蚀能力与流量之间存在明显的线性关系,与坡度之间存在较好的对数关系。试验方法与其他方法相比,操作便捷、结果吻合度高,能较好地确定黄土区细沟侵蚀的剥蚀能力。研究结果可进一步完善黄土坡面细沟侵蚀理论。

Laboratory Study of Detachment Capacity Under Rill Erosion on the Loess Slope

In order to study the law of rill erosion on the loess slope, and explore the indoor calculation method for the detachment capacity of water flow, this paper took loess soil as the research object, four flow rates (2, 4, 6, 8 L/min), and four slope gradients (5°, 10°, 15° and 20°) were set up, and the length of soil trough was 12 m. The critical rill length and sediment transport capacity of loess soil slope were obtained. Based on the functional relationship between the above two factors, the calculation formula of detachment capacity was deduced. According to this, the change rules of critical ditch length, sediment transport capacity and detachment capacity under different test conditions were analyzed, and the accuracy of this test method was verified. The results showed that under the designed hydraulic conditions, the critical rill length of rill erosion on loess slope varied from 5.33 to 11.12 m, and the critical rill length decreased with the increase of flow rates and slopes, and the sediment transport capacity increased with the increase of flow rates and slopes. There was an obvious linear relationship between detachment capacity and flow rate, and a logarithmic relationship between detachment capacity and slope. Compared with other methods, this test method had the advantages of convenient operation and high coincidence of results, and could better determine the denudation ability of rill erosion in loess area. The research results can further improve the theory of rill erosion on the loess slope.