土壤结皮对坡面水分入渗及侵蚀产沙具有重要影响,但其具体作用过程和机理尚存在一定争论。以乌拉山矿山废弃地客土坡面为研究对象,采用原位冲刷试验,研究不同坡长(2,4,6,8,10 m)和产流产沙过程中,土壤结皮对径流泥沙的影响。结果表明:(1)2 m土壤结皮坡面总径流和泥沙量显著增加,分别是对照坡面的2.17,1.56倍;4~10 m土壤结皮坡面总径流量和总泥沙量降低,其中总径流量为对照坡面的67.17%~78.45%,总泥沙量为对照坡面的54.53%~83.56%。(2)土壤结皮坡面与对照坡面产流速率随产流时间变化基本一致,呈现波动稳定或略微提高趋势;产沙速率在对照坡面随产流时间呈下降趋势,而在结皮土壤坡面呈现下降与稳定2种趋势。(3)累积径流量、累积泥沙量与产流时间关系均可用线性函数和幂函数表达。随产流时间变化,土壤结皮坡面对累积径流量的影响可分为全程提高、全程降低、先提高后降低3种类型,对累积泥沙量的影响可分为提高与降低2种类型。因此,土壤结皮对坡面产流产沙过程的抑制或促进作用与坡长和侵蚀发生过程密切相关。
Soil crust has an important influence on water infiltration and erosion sediment production on slope, but its specific process and mechanism are still under debate. In this study, taking the alien soil slope in mining wasteland of Wula Mountain as the research object, the effects of soil crust on runoff and sediment were investigated by in situ scouring tests on the slopes with different slope lengths (2 m, 4 m, 6 m, 8 m and 10 m) and during flow and sand production process.The results showed that:(1) The total runoff and sediment yield on the 2 m slope increased significantly, which were 2.17 and 1.56 times of that on the control slope. The total runoff and sediment yield on the 4 to 10 m slopes decreased, and the total runoff was 67.17% to 78.45% of that on the control slope and the total sediment yield was 54.53% to 83.56% of that on the control slope. (2) The changes of runoff rate with time on the soil crust slope and the control slope were basically the same, showing a fluctuating and stable or slightly increasing trend. The sediment yield rate on the control slope showed a decreasing trend with time, while on the soil crust slope showed two trends of decreasing and stabilizing. (3) The relationship between cumulative runoff, cumulative sediment yield and runoff generation time could be expressed by linear function and power function. With the change of runoff generation time, the effects of soil crust slope on the accumulated runoff volume could be divided into three types:increase, decrease, increase firstly and then decrease. And the effects on the accumulated sediment yield could be divided into two types:increase and decrease. Therefore, the inhibiting or promoting effect of soil crust on process of runoff and sediment yield on the slope surface was closely related to the slope length and erosion occurrence process.
张馨予, 张晓霞, 王冬, 宋俊玲, 崔轻舟, 张泽宇, 裴益乐, 查同刚.土壤结皮对乌拉山矿山废弃地客土坡面侵蚀特征的影响[J].水土保持学报,2023,37(5):24~30复制