Time Series Variation in the Driving Factors Leading to Land Desertification in Yanchi County Over the Last 50 Years

Abstract

This study evaluates the time series variation in the driving factors that lead to land desertification in Yanchi County,Ningxia Hui Autonomous Region,China based on factor analysis of the currently available data.The results demonstrated that human activities accounted for 72.22% of the process of land desertification between 1981 and 2002,which was 11.56% and 14.4% higher than the contribution rates between 1953 and 1980 and between 1981 and 2006,respectively.The contribution rate of natural factors accounted for 29.21% of desertification between 1953 and 1980,which was 12.64% higher than the contribution of natural factors during the period from 1981 to 2002 but 3.19% lower than the contribution between 1981 and 2006.Moreover,the proportion of the integrated factors during these three periods was approximately the same.Such changes indicate that the impact of human activities on desertification increased continuously prior to 2002.The results also demonstrate that the excessive economic activities are the primary factors leading to land desertification in Yanchi Countya.Therefore,it is suggested that rural industrialization be developed to increase the value of farm and side products and the per capita income of farmers' households so that the ecologically destructive farming activities currently in place can be phased out.In addition,the results of this study demonstrate that implementation of the prohibition of grazing in areas where the ecology is fragile and soil erosion is serious plays an active role in conservation of the environment.