工程堆积体坡面不同植被格局的控蚀效果研究

Study on Erosion Control Effect of Different Vegetation Patterns on Slope Surface of Engineering Accumulation

为探明不同植被格局对工程堆积体陡坡坡面土壤侵蚀的影响,采用10,20,30 L/min 3种放水流量,对黄土区不同格局(裸坡、坡顶、坡中、坡底、条带)下的高陡边坡(32°,20 m×1 m)进行模拟放水试验,选取径流率、产沙率、减流效益、减沙效益等因子对堆积体坡面植被的控蚀效果进行分析。结果表明:3种放水流量下,条带、坡顶、坡中、坡底的平均径流率较裸坡分别减小57.33%,61.17%,41.62%,24.78%,平均产沙率较裸坡分别减小74.99%,61.10%,55.01%,46.43%,且径流率与产沙率的线性关系(R^(2)=0.57~0.80,p<0.01)整体上弱于裸坡(R^(2)=0.71,p<0.01)。不同植被格局中,条带及坡顶格局的减流效益分别是65.97%,60.52%,减沙效益分别为71.44%,57.22%,二者的控蚀效果远高于其他格局。产沙率与径流功率的线性相关性(R^(2)=0.61~0.83,p<0.01)高于径流剪切力(R^(2)=0.29~0.76,p<0.01),径流功率能更好地反映堆积体坡面土壤侵蚀机制。

In order to explore the soil erosion control effect of different vegetation patterns on the slope surface of engineering accumulation,the high and steep slopes(32°,20 m×1 m)with different patterns(bare slope,top slope,middle slope,bottom slope and strip slope)in the loess region were simulated with three water discharge rates of 10,20 and 30 L/min.The runoff rate,sediment yield rate,flow and sediment reduction benefit were selected to analyze the erosion control effect of vegetation patterns on the slopes of engineering accumulation.The results showed that the average runoff rates of strip,slope top,slope middle and slope bottom were 57.33%,61.17%,41.62%,24.78%lower than that of bare slope,and the average sediment yield rates were 74.99%,61.10%,55.01%,46.43%lower than that of bare slope.The linear relationship between runoff rate and sediment yield rate(R^(2) was 0.57 to 0.80,p<0.01)was weaker than that of bare slope(R^(2)=0.71,p<0.01).In different vegetation patterns,the flow reduction benefits of strip pattern and slope top pattern were 65.97%and 60.52%,respectively,and the sediment reduction benefits were 71.44%and 57.22%,respectively.The erosion control effects of strip pattern and slope top pattern were much higher than other patterns.The linear correlation between sediment yield and runoff power(R^(2) was 0.61 to 0.83,p<0.01)was higher than that of runoff shear force(R^(2) was 0.29 to 0.76,p<0.01).Runoff power could better reflect the mechanism of soil erosion on the slope of accumulation.