坡面产流产沙影响因素的灰色关联法分析

影响坡面径流的因素有降雨量、雨强、植被等诸多因子。在陕西省长武县王东沟小流域布设径流小区,采用灰色关联度的方法,对不同影响因子进行了对比分析,研究了降雨和植被对地表径流量和侵蚀量的影响。结果表明,降雨量与径流量、侵蚀量的关联度最大,各因子对径流量的影响系数排序为:降雨量>最大雨强>雨强>植被覆盖度,对侵蚀量的影响系数排序为:降雨量>雨强>最大雨强>植被覆盖度。植被覆盖度与径流量和侵蚀量的关系为:当覆盖度<25%时,径流量没有明显变化;当其>25%时,径流量随着覆盖度的增加减少;当覆盖度<50%时,随着覆盖度的增加,侵蚀量下降趋势明显;当其>50%时,随着覆盖度的增加,侵蚀量下降趋势趋于平缓。

Gray Correlation Analysis on Influential Factors of Runoff and Erosion in Slope Lands

Many parameters were recognized as affecting factors of slope runoff,such as precipitation volume,precipitation intensity and vegetation.Runoff plots were established in a small watershed,Wangdonggou of Changwu County,Shaanxi Province.The method of grey rational degree was applied to analyze the effects of the precipitation and vegetation on slope runoff and erosion by comparing influencing factors.The results indicate precipitation had the highest rational degree with slope runoff and erosion.The parameters contributing to slope runoff in the descending order were rainfall volume,maximum rainfall intensity,rain intensity,and vegetation coverage.The parameters contributing to erosion in the descending order of rational degree were rainfall,rain intensity,maximum rainfall intensity,and vegetation coverage.When the coverage was lower than 25%,runoff volume was similar;when the coverage was over 25%,runoff volume reduced with increasing coverage.When the coverage was lower than 50%,the total erosion decreased rapidly with the increasing coverage.However,the erosion-reducing efficiency of the vegetation significantly decreased when the coverage was higher than 50%.