Correlation between Comprehensive Soil Erodibility Index and Environmental Factors in the Qilian Mountains,China
The Qilian Mountains area is a national key conservation and prevention zone for soil-water loss in China.Soil erodibility index is a key parameter for estimating soil erosion and evaluating soil-water conservation benefits,but the specific knowledge of soil erodibility in the Qilian Mountains area was in a fragmented state,far from application.In this study,it explored the distribution characteristics of Comprehensive Soil Erodibility Index(CSEI)in the Qilian Mountains area and its driving factors using spatial analysis and Geodetector methods based on the National Water and Soil Conservation Zoning(NWSCZ)issued in 2012 by Ministry of Water Resources of China.It found that(1)in the Qilian Mountains area,CSEI value ranged from 0.16 to 0.54,with an average of 0.38.The areas with low-value CSEI(0 to 0.20)occupied the smallest lands,primarily in the southeast of the Qinghai Lake Plateau mountain ecological conservation area(Zone V).The median-value areas(0.20 to 0.40)covered the largest area,mainly in the Longzhong Hills Gully water storage conservation area(Zone Ⅰ)and in the Qingdong-Gannan Hills Gully water storage conservation area(Zone Ⅳ),the farmland protection and sand prevention area in Hexi Corridor(Zone Ⅱ),the mountain water conservation and soil conservation area in the Qilian Mountains(Zone Ⅲ),and the east of Zone V.The high-value area(0.40 to 0.60)covered a large area,mainly in the west of Zone Ⅱ,Ⅲ,V and the farmland protection and sand prevention area of the Qaidam Basin(Zone Ⅵ).(2)Slope,annual precipitation and normalized vegetation index(NDVI)had a significant impact on CSEI spatial differentiation.(3)NDVI expressed strong explanatory power concerning the spatial distribution of CSEI and was the primary driving factor for 89.38％area of the study area.There was a considerable difference in the types of dual driving factors.The driving factor was the average annual wind speed ∩ NDVI(q=0.95)in ZoneⅠ,the annual precipitation ∩ NDVI(q=0.73 and 0.63)in Zone Ⅱ and Zone Ⅲ,the land use ∩ average annual temperature(q=0.37)in Zone Ⅳ,the land use ∩ NDVI in Zone V(q=0.65),and the annual precipitation ∩average annual wind speed(q=0.17)in Zone Ⅵ.According to comprehensive analysis,the western Qilian Mountains has less precipitation,strong wind speed and higher soil erodibility.In the eastern region,precipitation is relatively high,vegetation coverage is high,and soil erodibility is low.The research can provide a theoretical basis for implementing of ecological protection projects in the Qilian Mountains,and formulating of policy-making.
CSEIGeodetectorsoil and water conservationthe Qilian Mountains
万方数据
维普
