黄土高原林草水土保持有效盖度分析

根据黄土高原绥德、延安、安塞和离石等地林、草地径流小区降雨侵蚀资料，对不同降雨和坡度下林、草地水土保持有效盖度进行了分析，建立了林地、草地水土保持临界有效益度与降雨及坡度的关系式。在土壤和植被类型相对稳定的条件下，林、草地的有效益度随着降雨和坡度的增大而增大，当临界有效益度达到一定程度时，降雨和坡度的影响减弱；在其它条件相同时，同一水土保持作用所要求的有效盖度草地比林地大。并结合降雨频率分析，得出了林、草措施抵抗不同年遇暴雨时的临界有效盖度。

Using rainfall erosion data from a woodland and a grassland runoff plot in Snide, Yanan and Ausai on the loess plateau, the effective cover rate of woodland and grassland for soil and water conservation in different rainfall and slope conditions was analyzed. The relationship between the critical effective cover rate (v) and a rainfall index (product of total rainfall amount and maximum 30 min rainfall intensity represented by (Pi30)) and slope steepness (s)is: woodland: v =- 103. 29 + 33. 81log (Pi30 ) + 7...