Temporal And Spatial Changes And Driving Forces Of Desertification In Western Sichuan Plateau

Land desertification as one of the most serious ecological problems hinders a region important factor in sustainable development,seriously restricting the social and economic development and the improvement of people's living standards and giving the ecological environment,resources and other great harm.Accurate evaluation of desertification,timely and effective grasp of desertification dynamics and driving factors can guide desertification control decision-making,which has important significance.The western Sichuan plateau is located in western Sichuan,which is one of the most serious desertification areas.Based on index selection principle about desertification and combining with the specific performance of desertification in the western Sichuan plateau,this paper evaluates the desertification and analyzes the characteristics and driving forces of desertification in the western Sichuan Plateau from 2001 to 2014.The main results and conclusions are as follows.(1)Vegetation coverage,slope,soil texture and wet index from the aspect of vegetation,topography,soil and climate is used to construct evaluation index system and the paper evaluates the desertification of western Sichuan plateau,obtaining spatial distribution of desertification.Most of the desertification areas are distributed in the west of the Shaluli Mountains,the vicinity of the northern part of the Bayan Har Mountains and the part of the Great Snow Mountain,Qionglai Mountain and the south of Minshan Mountains.Besides the least region distribute in the northeastern part of the study area.(2)The area of the reversed desertification is about 8745.81km~2,accounting for 3.51% in the study area.The development of desertification is about 4666.50km~2,accounting for 1.87% in the study area.Among them,the average annual change rate of heavy desertification area is the largest.The slight and moderate rate of change is small.But the change area and transfer rate of slight and moderate desertification land were higher in 14 years,while the area of change and the transfer rate of heavy desertification were smaller.The slight,moderate and heavy desertification showed decreasing tendency.The above indicate that the natural environment gradually improves in the 14 years,slight and moderate desertification response to the environment for the greatest.(3)In different altitude,the distribution of desertification is different.The higher altitude has a lot of desertification,which is due to the top of the mountain snow and glacier accumulation,as well as snow and glaciers melt the erosion of the region,so that the region has very little vegetation cover.The lower altitude has less desertification,which is due to the better growth environment for the vegetation and the less erosion.(4)The main driving forces of desertification are natural factors and human factors in the western Sichuan plateau.The contribution rate of natural factors to desertification is low and the contribution rate of human factors is relatively large.In different altitude,the contribution rate of natural and human factors is different.In higher altitude,the desertification change is lower in the influence of human factors and is higher in the influence of natural factors,so the rate of desertification change.is slower.With the continuous improvement of the quality of the population and the encouragement of the national policy,the environment of the western Sichuan Plateau has been continuously improved under the human action,and the desertification has been gradually reduced.