模拟雨滴条件下崩壁不同土层的溅蚀特征

Splash Erosion Characteristics of Different Soil Layers on the Collapsing Wall Under Simulated Raindrop

崩壁是崩岗侵蚀的重要组成部分,为了研究崩壁不同土层的溅蚀特征,采用自制雨滴发生装置模拟不同直径雨滴,分析了不同雨滴大小和雨强下崩壁3个土层溅蚀量、溅蚀土壤颗粒特征的差异。结果表明:崩壁3个土层的溅蚀土粒均大都分布在0—5cm的范围内,其中,红土层的溅蚀量随雨滴强度的变化率最大,碎屑层次之,砂土层最小;通过双因素方差分析可知,土壤特性对溅蚀量的影响大于雨滴强度;溅蚀土粒中砂粒(0.05~2mm)百分比最大,而黏粒(<0.002mm)百分比最小,可以推测出使溅蚀量达到最大的粒径范围;崩壁3个土层的溅蚀土粒中,随着溅蚀距离的增加,砾石(>2mm)最不易被溅移,粉粒(0.002~0.05mm)和黏粒(<0.002mm)最易被溅移。

Collapsing wall is an important part of the collapsing hill erosion. In order to study splash erosion characteristics in different soil layers of collapsing wall, a raindrop generator was made to simulate different diameter raindrops, and we studied the splash amount and different characteristics of the soil particles in different soil layers of collapsing wall under the raindrop size and different raindrop intensities. The result shows that the soil particles of splash erosion present the concentrated distribution in the range of 0 to 5 cm, among which the red soil splash erosion with the rate change of rain intensity is the maximum, the second is the clastic, and the minimum is the sand layer. By two-factor variance analysis, the influence of soil characteristic on splash erosion amount is greater than the rain intensity. The mass percentage of particles with size of 0.05-2 mm was the most, while the mass percentage of particles with size less than 0. 002 mm was the least, which can speculate the size range that makes splash amount reach the maximum. With the increase of splash erosion distance, soil particles with size more than 2 mm are the most difficult to be moved due to splash, while soil particles with size of 0. 002-0.05 mm and with size less than 0. 002 mm are the most vulnerable to be moved through splash.