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为有效防治喀斯特山区土壤侵蚀和遏制石漠化,选取贵州喀斯特山区分布较广的石灰土作为测试土样,开展不同雨强、不同坡度条件下湿态石灰土坡面产流产沙过程的人工模拟降雨试验,研究土壤坡面水沙过程及机理。结果表明:1)当坡度较小时(6°),雨强越大,径流量达到稳定需要的时间越短,这种变化趋势随坡度的增大而减弱。坡面径流量随雨强、坡度的增大而增大。2)坡面输沙率随时间的变化趋势相同。0~10min迅速减小,10min以后缓慢减小,并逐渐趋于稳定。当雨强和坡度较大时,坡面开始发生纹沟侵蚀,使得输沙率呈增大减小的起伏变化。输沙率随雨强、坡度的增大而增大。3)坡度相同时,坡面总径流量随雨强的增大而增加,雨强相同时,坡面总径流量随坡度的增大而增加。土壤含水量饱和(或接近饱和)的条件下,坡度依然是影响地表水入渗系数的主要因素。
In order to effectively control soil erosion in Karst mountain area and to control rocky desertification, limestone soil with wider distribution in Guizhou Karst mountain area was selected as test soil sample to carry out artificial simulation of runoff and sediment production process under different rainfall intensity and different slope conditions Rainfall test to study soil water and sediment process and mechanism. The results show that: 1) when the slope is small (6 °), the greater the rainfall intensity, the shorter the time required for the runoff to reach a steady level. The trend of this trend is weakened with the increase of slope. Slope runoff increases with rainfall intensity and gradient. 2) The trend of sediment transport rate over time is the same. 0 ~ 10min decreased rapidly, slowly decreased after 10min, and gradually stabilized. When the rainfall intensity and gradient are large, the groove erosion begins to occur on the slope, which makes the sediment transport rate increase and decrease. Sediment transport rate increases with rainfall intensity and gradient. 3) When the slope is the same, the total runoff of slope increases with the increase of rainfall intensity. When the rainfall intensity is the same, the total runoff of slope increases with the increase of slope. Under the saturated (or nearly saturated) soil moisture content, the slope is still the main factor affecting the infiltration coefficient of surface water.