青海省黄土丘陵沟壑区沟蚀影响因子的贡献率

Contributing ratio of impact factor on gully erosion in Loess hilly and gully area of Qinghai province

以青海乐都县峰堆乡小流域6条侵蚀沟为研究对象,用钢钎法测定了年侵蚀模数,根据土壤砂粒、粉粒、粘粒和有机质的质量分数求算可蚀性K值,进行年侵蚀模数与植被盖度、坡度、K值之间的多元回归分析,采用标准化处理,来确定相对贡献率,探讨了3个指标对侵蚀沟的影响。结果表明:随着盖度增加侵蚀沟年侵蚀模数明显降低,沟蚀量对植被盖度的敏感度有随盖度升高而降低的趋势,沟蚀量有随坡度和可蚀性K值增加而上升的趋势。植被盖度、坡度和K值变化对峰堆小流域沟蚀量变化的贡献率分别为66.97%、7.12%和25.91%,可见沟蚀量受植被盖度的影响要大于坡度和K值的影响。

Taking six gullies in Fengdui township, Ledu county, Qinghai province as research object, this paper focused on the effect of three indicators on erosion gully, of which annual erosion modulus is measured by the method of steel rod, the erodibility factor K was calculated by soil contents of sand, silt, clay and organic matter and the relative contribution rate was determined by the standardization of process and the multiple-regression analysis among annual erosion modulus, vegetation coverage, slop and factor K. The results showed that the annual erosion modulus would decrease significantly with the increase of vegetation cover and there would be some trends that the sensitivity of erosion amount to vegetation cover would decrease with the increase of the vegetation cover and the erosion amount would become larger with the increase of slope and factor K. The contributing ratio of vegetation cover, slope and factor K changes were 66.97%, 7.12% and 25.91%. It was obvious that the influences of vegetation cover were larger than those of slope and factor K for the soil erosion in the study area.