风水两相侵蚀对坡面产流产沙特性的影响

为了研究黄土高原风蚀水蚀交错区两相侵蚀的交互作用,该试验采用风洞和模拟降雨相结合的方法,探讨了风水两相侵蚀条件下坡面降雨入渗、产流产沙特征。结果表明:相对于未风蚀处理,中度风蚀处理(风速14m/s)使坡面产流时间延长,轻度风蚀处理(风速11m/s)对产流时间影响不大(P>0.05);风蚀处理(风速11m/s、14m/s)使坡面入渗率降低2.9%～10.0%,径流强度增加4.5%～21.7%,侵蚀率增加7.3%～39.0%,不同风速间差异不显著(P>0.05),且影响程度均随雨强的增大而降低;风力、水力两种侵蚀营力相互促进导致坡面糙度增大,风速14m/s、雨强100mm/h时,坡面糙度是风速11m/s、雨强60mm/h时的3倍。研究结果为评价风水两相侵蚀效应提供理论依据。

Effects of wind and water double erosion on characteristics of runoff and sediment from slope lands

In order to investigate the interaction of wind and water double erosion in the crisscross region of wind-water erosion on the Loess Plateau, the experiment of wind tunnel combined with simulated rainfall was conducted, and the effects of wind-water erosion on the characteristics of infiltration, runoff and sediment on slope were analyzed. The results showed the runoff producing time under water erosion was increased by moderate wind erosion intensity treatment with a wind speed of 14 m/s compared with no wind erosion. However, light wind erosion intensity treatment with a wind speed of 11 m/s hardly affected slope runoff producing time (P>0.05). Compared with no wind erosion, wind erosion intensity treatment could reduce rainfall infiltration rate by 2.9%-10.0%, increase slope runoff intensity and erosion rate by 4.5%-21.7% and 7.3%-39.0% respectively. Rainfall infiltration rate, slope runoff intensity and erosion rate had no significant difference between two wind speeds (P>0.05), but these factors reduced with the increment of rainfall intensity. Slope roughness increased obviously under wind and water double erosion. Under the wind speed at 14 m/s and rainfall intensity at 100 mm/h, slope roughness was 3 times higher than that under wind speed of 11 m/s and rainfall intensity 60 mm/h. The study provides theoretical foundation for evaluating the effect of wind and water double erosion.