天山山区草地覆被和雨强对产流和产沙的影响研究--以天山天池自然保护区为例

通过设在天山天池的实地径流小区试验观测,分析了天山天池自然保护区草地覆被变化和雨强对产流和产沙的影响.结果表明,(1)植被覆盖度对产沙的影响大于对产流的影响.植被覆盖度为35%的退化草地径流场内的总径流深和总侵蚀量分别是50%,55%,75%.这3种植被盖度场地内总径流深的1.4,1.5,2.2和4,6,10倍;总的径流深、总的侵蚀量与植被覆盖度之间的关系可分别用指数函数表示.(2)降雨强度对于产沙的影响大于对产流的影响.在下垫面条件一定时,降雨强度越大,径流量、侵蚀量也越大;径流量、侵蚀量与降雨强度之间的关系可以分别用多项式表示.(3)径流系数与植被覆盖度之间的关系可以用指数函数关系表示.

Impacts of Grass Coverage and Rainfall Intensity on Runoff and Sediment Yield in Tianshan Mountains of China

Based on the experiment on plots, impacts of grass coverage change on runoff and sediment yield in the Tianchi Lake Natural Reserve Area in Xinjiang were investigated. Grass coverage had much more influence on sediment yield than that on runoff. Total runoff depth for 35% grass coverage was 1.4 , 1.5 , and 2.2 times that for 50 % , 55 %, and 75 % grass cover degrees, and total sediment yield for 35 % grass coverage was 4, 6, and 10 times that for 50 %, 55 %, and 75 % grass cover degrees, respectively. The relations of grass coverage to total runoff and sediment yield can be described by exponential function. Rainfall intensity had much more influence on sediment yield than runoff. In the same condition of grass coverage, runoff and sediment yield were increased with increased rainfall intensity. The relation of rainfall intensity to total runoff and sediment yield can be described by binomial function. The relation between grass coverage and total runoff depth can be described by exponential function.