人工降雨条件下云南红土坡面土壤侵蚀特性

目的]揭示降雨强度、坡度和坡长与云南红土坡面土壤侵蚀之间的关系,为云南红土地区土壤侵蚀的防治提供依据。方法]采用室内人工模拟降雨试验及理论分析相结合的方法。结果](1)红土坡面侵蚀模数与降雨强度、坡度和坡长的相关关系显著(R20.95)。(2)在相同坡度、坡长条件下,红土坡面侵蚀模数与降雨强度呈幂函数关系;(3)在相同降雨强度、坡长条件下,红土坡面侵蚀模数与坡度呈二次多项式关系;(4)在相同降雨强度、坡度条件下,红土坡面侵蚀模数与坡长呈二次多项式关系。结论]云南红土坡面侵蚀模数随降雨强度的增大而增大;当坡度小于临界坡度21.4°时,坡面侵蚀模数随坡度的增大而增大,当坡度大于临界坡度21.4°时,坡面侵蚀模数随坡度的增大而减小;坡面侵蚀模数随坡长的增大而增大。

Erosion Characteristics of Yunnan Laterite Under Artificial Rainfall Conditions

Objective] Revealing the slope erosion of Yunnan laterite as dependent variable caused by independent variables of rainfall intensity, slope gradient, slope length in order to provide bases for the prevention and control of soil erosion in Yunnan laterite area. Methods] Artificial rainfall erosion was simulated indoor and analyzed theoretically. Results] (1) The slope erosion of Yunnan laterite could be regressed significantly with rainfall intensity, slope gradient, slope length(R²>0.95). (2) Under certain slope gradient and length, the slope erosion modulus of laterite had power function relationship with rainfall intensity as independent variable. (3) Under certain rainfall intensity and slope length, the slope erosion modulus of laterite had a quadratic polynomial relationship with slope gradient. (4) Under certain rainfall intensity and slope gradient, the slope erosion modulus of laterite had a quadratic polynomial relationship with slope length. Conclusion] The slope erosion modulus of Yunnan laterite increased with the increase of rainfall intensity. When the slope was less than the critical slope 21.4°, slope erosion modulus increased with the increase of slope. When the slope is greater than the critical slope 21.4°, slope erosion modulus decreased with the increase of slope. The slope erosion modulus increased with the increase of the slope length.