黄土高原典型区降雨植被耦合对侵蚀产沙影响的临界研究

Critical Study on Influence of Precipitation and Vegetation Coupling of Typical Area in the Loess Plateau to Erosion and Sediment Yield

降雨植被耦合对土壤侵蚀的影响是研究地表侵蚀过程的重要内容。根据1954—1986年西峰水土保持科学试验站人工草地和自然草地径流场观测资料,从微观角度分析了降雨植被耦合对土壤侵蚀的影响。研究结果是:当牧草覆盖度<10%时,极端侵蚀模数随着植被覆盖度的增大而增大,这说明要使植被起到有效的抗蚀作用,其覆盖度不应低于10%;当植被覆盖度>10%时,极端侵蚀模数与植被覆盖度呈良好的幂函数关系;如果要使植被抗蚀力起主导作用且达到最优效果,则其覆盖度至少要达到70%。

The influence of precipitation and vegetation coupling to soil erosion is an important issue of surface erosion process study. The paper analyzed the influence of precipitation and vegetation coupling to soil erosion from microscopic point of view based on the observed data of runoff plots of artificial grassland and natural grassland of Xifeng Soil and Water Conservation Experimental Station in the period of 1954-1986. The outcomes show that when the vegetation coverage is smaller than 10%,the extreme erosion modulus is increased along with the increase of vegetation coverage. This shows that the coverage should not be lower than 10% for effective anti-erosion. When the vegetation coverage is greater than 10%,the extreme erosion modulus shows good power function relationship with vegetation coverage. The vegetation coverage should at least reach to 70% if hoping the anti-erosion ability playing a major role and achieving optimal effect.