玉米冠下溅蚀效应及其空间分布特征

Splash detachment effects and its spatial distribution under corn canopies

为系统测定玉米不同生长阶段冠下的溅蚀速率及其空间分布特征,采用室内人工降雨的方法,系统测定了不同降雨强度、不同生长阶段玉米冠下的穿透雨强度和溅蚀速率,分析了玉米冠下溅蚀速率与叶面积指数和穿透雨强度的关系,探讨了冠下溅蚀速率的空间分布特征。结果表明:玉米在其不同生长阶段冠下平均溅蚀速率较裸地减少了约43%～77%;冠下溅蚀速率随叶面积指数变化规律不显著,但是随降雨强度的增大而显著增加。冠下各点溅蚀速率随相应各点的穿透雨强度的增加而增加。玉米冠下溅蚀速率的空间分布与穿透雨的分布具有较好的对应关系,冠下穿透雨强度较大的区域会导致较高的溅蚀量。该研究揭示的玉米冠下溅蚀速率特征可为坡耕地土壤侵蚀防治提供理论指导。

In order to systematically determine the splash detachment rate and spatial distribution characteristic at different growth stages of corn under different rainfall intensities, this study systematically investigated the throughfall and splash detachment rate at different growth stages of corn under different rainfall intensities, analyzed the relationship between splash detachment rate and LAI and throughfall intensity, and discussed the spatial distribution of splash detachment rate under corn canopies. The results showed that in the whole growing season, the average splash detachment rate under corn canopy was about 43 to 77% lower than that on bare soil. The splash detachment rate was not significantly related to LAI, but increased significantly with rainfall intensity. The splash detachment rates at different positions under canopy were considerably influence by the thoughfall intensities at the corresponding positions and increased with thoughfall intensity. The spatial distribution of splash detachment rate was well related to the distribution of throughfall, and the areas that had higher throughfall intensity also had extremely high splash detachment rate. The splash detachment characteristic proposed by this study would provide theoretical guidance for erosion control on slope lands.