【摘要】 [目的]探究连续降雨条件下不同砾石含量对陕北沙壤土上方有来水工程堆积体坡面产流产沙的影响，为生产建设项目水土流失治理提供数据支撑和理论参考。[方法]通过室内模拟降雨试验，研究不同砾石含量(0,10%,20%,30%,40%)工程堆积体坡面土壤水动力学特性及产流产沙特征。[结果](1)降雨强度相同，随砾石含量增加，工程堆积体坡面初始产流时间表现为递减趋势，减幅为27.22%～64.62%,35.09%～71.70%,47.37%～78.77%,51.75%～82.31%。次降雨径流率表现为“迅速增加—稳定波动”的变化趋势，平均径流率随砾石含量、降雨时间的增加显著增大；但产流峰值随砾石含量增加而降低，且出现时间逐渐提前。(2)试验各场次雷诺数的变化范围介于74.13～165.05,均小于500,水流属于层流；弗劳德数的变化范围集中在2.14～3.71,表现为急流。水流剪切力、水流功率和单位水流功率随降雨场次的增加而显著增加。(3)0%～40%砾石含量工程堆积体坡面侵蚀速率介于0.45～6.73,0.13～4.09,0.25～1.26,0.14～0.96,0.13～0.88 g/(m~2·min),各砾石含量堆积体减沙幅度分别为36.06%,49.05%,55.23%和56.62%,其中砾石高覆盖度(40%)的沙壤土工程堆积体坡面土壤侵蚀强度较小。[结论]砾石覆盖在沙壤土工程堆积体坡面的水土流失过程中可显著降低土壤侵蚀速率，从而实现拦蓄水土，保持较高的减沙效益。更多还原

【Abstract】 [Objective] The impact of different gravel contents on soil erosion of engineered deposit slopes were explored in the sandy soil region of Northern Shaanxi Province under continuous rainfall conditions in order to provide data support and theoretical references for soil erosion control in production and construction projects. [Methods] Indoor rainfall experiments were conducted to study the hydrodynamic, runoff, and sediment characteristics of engineered deposit slopes with varying gravel contents(0%, 10%, 20%, 30%, 40%). [Results](1) Under the same rainfall intensity, the initial runoff time on the engineered deposit slopes showed a decreasing trend with the increase of gravel content, with ranges of 27.22%—64.62%, 35.09%—71.70%, 47.37%—78.77%, and 51.75%—82.31%, respectively. The runoff coefficient during subsequent rainfall events exhibited a “rapid increase-stable fluctuation” trend, and the average runoff coefficient increased significantly with increasing gravel content and rainfall duration. However, the peak value of runoff decreased with increasing gravel content, and the occurrence time of the runoff peak was gradually advanced.(2) The Reynolds index for all experiments ranged from 74.13 to 165.05, all of which were below 500, indicating that the flow type was laminar flow, while the Froude number ranged from2.14 to 3.7l indicating rapid flow. The shear force, flow power, and unit flow power increased with increasing rainfall time.(3) The ranges of erosion modulus on the engineered deposit slopes were 0.45—6.73, 0.13—4.09, 0.25—1.26, 0.14—0.96, and 0.13—0.88 g/(m~2·min), respectively. The sediment reductions for each gravel content were 36.06%, 49.05%, 55.23%, and 56.62%, respectively. The highest gravel coverage(40%) resulted in the lowest soil erosion intensity of the engineered deposit slopes in the sandy soil region. [Conclusion] Gravel coverage on engineered deposit slopes of sandy loam soil significantly reduces soil erosion rate, thereby achieving soil retention and maintaining high sediment reduction benefits.更多还原