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利用坡面水蚀精细模拟降雨试验,对黄丘区陡坡(20°)条件下细沟流速分布特征进行了研究。通过对细沟形态演变过程的观察与分析,同时结合试验中对细沟间及细沟内流速的观测,给出了细沟发育过程中坡面流速沿程分布以及细沟内关键位置的流速分布。结果表明,细沟间流速分布基本不受细沟发育程度的影响,而细沟内水流流速与细沟发育过程之间存在互馈关系,首先坡面漫流向集中股流的转化促使细沟发育,会导致细沟内流速的增加,但随着细沟的进一步发展,汇流面积减小,沟床形态阻力及沟底跌坎消能作用增大,细沟流速又会逐渐减小,沟床形态阻力与径流集中产生的流速增量二者间的相互对比关系影响着细沟内水流速度。
Using the fine simulated rainfall experiment of slope water erosion, the distribution characteristics of the velocity of the rill under the steep slope (20 °) are studied. By observing and analyzing the morphological evolution of the rill, and combining with the observation of the velocities in the rill and the rill in the experiment, the distribution of the velocity along the slope and the key position in the rill during the development of the rill distributed. The results show that the distribution of velocity between the two flutes is not affected by the development of the flume. However, there is a mutual relationship between the flow velocity of the flume and the development of the flume. The transformation of the flow from the flume to the concentrated stream leads to the development of the flume , But with the further development of the gutter, the confluence area decreases, the shape resistance of the gutter bed and the energy dissipating effect of the ditching ridge increase, the velocity of the rill decreases, The correlation between the morphological resistance and the increment of the flow velocity caused by runoff concentration affects the velocity of water flow in the thin channel.