Research On Land Use/Cover Change And Driving Forces In Yanan,Shaanxi Province

This paper uses the four remote sensing images from 2000,2005,2010,and 2017 in Yan'an City,Shaanxi Province as the data source to obtain the land use/cover information for the four periods in the region.Utilize models of land use quantity change model,land use change degree model,land use/cover type transfer matrix,etc.to reveal the spatial and temporal characteristics of land use/cover change in Yan'an from 2000 to 2017;At the same time,based on the socio-economic statistics of Yanan City from 2000 to 2017,the principal component analysis method was used to analyze the driving force factors affecting land use/cover change in Yanan City.The main conclusions are:(1)The land use types in Yan'an are mainly grassland,woodland and arable land.The area of grassland accounts for 47%of the total area and is the most widely distributed;Followed by the area of land and arable land,accounting for 25%and 26%of the total area,the area of waters,construction land and unused land accounted for 2%of the total area.(2)From the analysis of the mutual conversion between land use types in the study area from2000 to 2017,the area of cultivated land continued to decrease.The main direction of cultivated land area was forest land and grassland,with an area reduction of 2424.44 km~2;The area of woodland and grassland gradually increased,mainly from the inflow of arable land,and the areas increased by871.74km~2 and 1368.87km~2,respectively,indicating that the implementation of the policy of returning farmland to forests,land improvement,and ecological environment construction policies in the study area has affected the land use changes in the study area.The water area increased,and the inflow was greater than the inflow.The inflow was mainly from grassland,arable land and forest land,which increased by 9.7 km~2;The area of construction land and unused land increased,mainly transferred to cultivated land,forest land and grassland,which increased by 147.39km~2 and 28.67km~2,respectively.(3)From the perspective of land use/cover change characteristics,the speed and degree of land use were analyzed using models such as land use dynamics and land use degree index.The results show that between 2000 and 2017,the area of cultivated land decreased year by year and the rate of change was obvious;the area of forest land,grassland,waters,construction land and unused land increased,with the obvious degree of change in the order of unused land,construction land,forest land,grassland and waters.The comprehensive land use dynamics showed an increasing trend and then a decreasing trend.The land use degree was the largest in 2005-2010.The comprehensive index of land use has gradually decreased,and the amount and rate of change in the degree of land use are both negative.The analysis of the above situation indicates that the land use in the study area is still in the adjustment period.(4)Qualitative description and related analysis of the driving forces of land use/cover between2000 and 2017.Natural factors have a small impact on land use/cover.Using SPSS software principal component analysis,qualitative analysis of land use/cover in the area Driven by change,The results show that the influence of human factors on land use/cover change is gradually strengthening.The leading factors affecting the changes in land use structure in the study area are social and economic development,population growth,agricultural development and changes in industrial structure.