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基于可控坡面进行多场次降雨试验,对覆沙坡面的产流产沙特性进行研究,以期为揭示黄土高原风蚀水蚀交错区风水复合侵蚀机理研究提供科学依据。结果表明:覆沙坡面的初始产流时间远大于裸坡,相对延迟了5.3~11.2倍,多场次降雨条件下,产流时间显著提前。首场降雨下,覆沙厚度为1cm,当雨强由1mm/min增加到1.5mm/min,覆沙坡面径流量、产沙量分别增加了0.87倍、0.85倍;雨强为1.5mm/min时,当覆沙厚度由0.5cm增加到1cm,首场降雨的径流量、产沙量分别减小了9.6%、12%。相对于裸坡,覆沙坡面产沙量较大,产沙过程较剧烈,首场降雨产沙量占总产沙量的70%以上,是裸坡的8.9~10.8倍,但在多场次降雨条件下,产沙量显著减小,并趋于稳定。研究结果表明坡面覆沙在一定程度上加剧了土壤侵蚀,可为揭示风蚀沉积物对水蚀过程的作用机理研究提供参考。
Based on multi-field rainfall experiments on controlled slope, the characteristics of runoff and sediment production on sand-covered slope were studied in order to provide a scientific basis for revealing the mechanism of compound erosion of wind and water in the ecotone between wind and water erosion in the Loess Plateau. The results show that the initial runoff time of overlying sand slope is much longer than that of bare slope, and the relative runoff time is 5.3 ~ 11.2 times. Under multiple rainfall conditions, the runoff time is significantly advanced. When the rainfall intensity increased from 1mm / min to 1.5mm / min, the runoff and sediment yield on the overburden slope increased by 0.87 and 0.85 times respectively; the rainfall intensity was 1.5mm / min, when runoff thickness increased from 0.5cm to 1cm, the runoff and sediment yield of the first rainfall decreased by 9.6% and 12% respectively. Compared with the bare slope, sandy sediment yield is larger and the sand production process is more violent. The first rainfall and sediment yield accounts for more than 70% of the total sediment yield, which is 8.9-10.8 times that of the bare slope. However, Under rainfall conditions, sediment yield decreased significantly and stabilized. The results show that the sand cover on the slope aggravates the soil erosion to a certain extent, which may provide a reference for revealing the mechanism of action of wind erosion on water erosion.