细沟侵蚀动力过程极限沟长试验研究

由细沟产生的野外动力条件,设计了室内细沟侵蚀模拟冲刷实验。从能量角度,分析了不同动力条件下侵蚀产沙量随沟长的变化规律。采用黄土高原黄绵土,在实验室内用水槽进行了5种坡度、3种流量下不同沟长时的细沟土壤侵蚀产沙的模拟侵蚀试验,测量沟长为0.5～8m。提出了由细沟侵蚀产沙随沟长变化函数关系的回归结果,在给定误差限下,估计水流含沙量达到极限值——水流输沙能力的细沟长度的计算方法。并据此方法,求得了不同坡度、流量条件下细沟侵蚀产沙达到极限值的细沟长度,且在不同水动力条件下的R²均大于0.81。

Dynamic Sediment Yield of Rill Erosion

Using a typical silt clay soil from the Loess Plateau, laboratory simulated experiments were conducted with a flume on 5 different slopes(5°,10°,15°,20°,25°) and 3 flow rates (2 L/min,4 L/min,8 L/min) to determine the relation of sediment yields to rill lengths of 0.5 to 8 m. A computational method was developed to estimate, with a given error, the sampling length at which sediment yield reached transport capacity, with the regressed functional relation of sediment load to rill length, which determined with experimental data obtained. With the suggested algorithm, sample lengths of rill on different slopes and at different flow rates were estimated with the related functional relation, as determined with the experiments. Further more, the influences of slope and flow rate on sample length were presented.