植被退化对典型草原地表径流的影响

Effects of Vegetation on Degradation Surface Runoff of Typical Steppe

通过野外径流测定、野外径流模拟实验与实验室径流模拟实验,对内蒙古锡林郭勒盟典型草原地表水分生态过程及其影响因子进行了系统分析,初步得出以下结论:(1)植被退化对典型草原地表径流有重要影响,地表径流与退化强度呈正相关,植被退化显著增加了地表径流系数和地表径流量。(2)植被层的植株高度、密度是影响地表径流的重要因子。地表径流均随着植被高度、密度的增加而降低。但在一定条件下,植被高度作用大于密度作用。(3)枯落物对径流的影响也非常明显,主要表现在直接截留作用和间接阻挡作用,在一定条件下,枯落物作用大于植被作用。

This dissertation has discussed the ecological process of the surface water of Inner Mongolia typical steppe and influencing factor by means of the method, which contains both the determination of runoff in field and simulated runoff in field and simulated runoff in the laboratory, here we present several key findings：First, the vegetation degradation is the primary factor causing fluctuations in surface runoff. A significant positive correla- tion was found between surface runoff and degradation intensity. The vegetation degradation both increased obviously with the surface runoff coefficient and runoff discharge. Second, the plant height and density of vegetation canopy is the primary factor causing fluctuations in surface runoff. The surface runoff coefficient and the surface runoff discharge decreases gradually along the plant height and density. However, the influence of plant height were higher than the influence of plant density on surface runoff at an certain condition. Third, the influence of litter on surface runoff was very serious, it was mainly influenced by directly interception effect and indirectly barrier effect. The influence of litter were higher than the influence of vegetation on surface runoff at an certain condition.