水保所知识产出(1956---)知识库

为明确砾石含量对关中塿土堆积体坡面径流和侵蚀特性的影响，采用室内模拟降雨试验方法，以土质坡面为对照，
研究了 10%、20%、30%三种砾石含量堆积体坡面的侵蚀特征。结果表明：（1）1.0 mm·min –1 雨强下，10%砾石含量时初始
产流时间最大，雨强＞1.0 mm·min –1 时，各坡面初始产流时间在 10%砾石含量时最小；（2）各砾石含量坡面平均流速均随雨
强增大而增大，1.0 和 2.5 mm·min –1 雨强条件下 10%砾石含量坡面流速最大，而 1.5 和 2.0 mm·min –1 雨强下，含砾石坡面流
速较土质坡面分别减少 15.3%～21.2%和 13.6%～14.1%；（3）不同雨强条件下各含砾石坡面含沙量在产流前期（0～6 min）
急剧下降；产流 6 min 后，含沙量在 1.0、1.5 mm·min –1 雨强下逐渐趋于稳定，在 2.0、2.5 mm·min –1 雨强下呈多峰多谷的变
化，该时期砾石主导产沙过程；（4）次降雨侵蚀量随雨强增大呈显著的幂函数关系；而随雨强的增大各砾石坡面侵蚀量较土
质坡面分别减少 22.4%～42.6%、8.2%～66.3%、2.2%～56.5%和 45.0%～68.3%。该研究可为关中地区堆积体坡面水蚀模型
的建立提供理论依据。

【Objective】 During the processes of production and construction in Guanzhong Region, a large number of stacks of
Lou soil were formed. Gravel in the stack is an important factor affecting soil erosion on stack slopes in characteristic. Therefore,
this study was designed to explore impacts of gravel concentration on runoff and sediment yielding processes on slopes of Lou
soil stacks different in gravel content.【Method】In this paper, artificial rainfalls were simulated indoor, different in intensity (1.0
mm·min –1 , 1.5 mm·min –1 , 2.0 mm·min –1 and 2.5 mm·min –1 ), to explore their effects on runoff and sediment yield on slopes of Lousoil stacks different in gravel content (0, 10%, 20% and 30%). The experiment had test plots set up, 5 m×1 m×0.6 m in area and
25° in slope gradient. The nozzles of the artificial rainfall simulator were 18 m high over the slopes, spraying water evenly(more
than 80% in evenness). Rainfall intensity were calibrated before the start of each test to ensure that the deviation of the actual
rainfall intensity in the test was kept less than 5% of the designed rain intensity for the test. During the test, flow velocity of the
runoff on the slope was measured with the dyeing method, width of the flow with a steel ruler, duration of runoff and sediment
collection recorded with a stopwatch, and quantity of the samples weighed on an electronic scale. 【Result】 Results show: (1)
runoff lasted the longest on the Lou soil slope 10% in gravel content under rainfall 1.0 mm·min –1 in intensity, and the shortest
under rainfall lower than 1.0 mm·min –1 in intensity; (2) mean flow velocity of runoff increased with rising rainfall intensity on all
the gravel-containing slopes regardless of gravel content. The flow velocity on the slope 10% in gravel content was the highest
under rainfalls 1.0 and 2.5 mm·min –1 in intensity, and 15.3%-21.2% and 13.6%-14.1% lower than that on the slope under rainfall
1.5 and 2.0 mm·min –1 in intensity, respectively; (3) sediment content in runoff dropped drastically during the initial period(0-6
min) of each rainfall, regardless of rainfall intensity on all the gravel-containing slopes, and 6 min later, it gradually leveled off
under the rainfalls 1.0 and 1.5 mm·min –1 in intensity, and fluctuated sharply under the rainfalls 2.0 and 2.5 mm·min –1 in intensity.
During this period gravels dominated the process of sediment yield; (4) the amount of erosion per rainfall event showed a
significant power function relationship with rainfall intensity, and decreased by 22.4%-42.6%, 8.2%-66.3%, 2.2%-56.5% and
45.0%-68.3%, on the gravel containing slopes under rainfall 1.0 mm·min –1 , 1.5 mm·min –1 , 2.0 mm·min –1 and 2.5 mm·min –1 in
intensity, respectively as compared with that on the pure soil slope. 【Conclusion】This study may serve as a theoretical basis for
establishment of a model for research on water erosion on slopes of soil stacks in the Guanzhong Region.