The Simulation Studies Of Spatial And Temporal Patterns Of Land Use By Conversion Drive Of Xiannangou, Ansai County, Shaanxi Province Which Based On CA

Land use/cover change is a complex geographical process of spatiotemporal dynamic change,and it is also the frontier of global environmental change research.The important way to study this problem is to conduct case analysis and research on typical regions.But how to simulate this process effectively is an important problem in this field.The cellular automata model based on GIS has the ability to simulate the evolution process of geographic space-time.In order to study the law and driving mechanism of land use change driven by conversion of cropland,firstly,CA model was extended,then integrated with GIS,and a new method to simulate the spatio-temporal dynamic process of land use change was put forward.Taking Xiannangou river basin in Ansai County of Shanxi Province as an example,the remote sensing images of the basin in 1995,2005 and 2015 were taken as the data source,combined with topographic maps and other related data.Based on the ArcGIS software,the spatio-temporal dynamics and evolution of land use before and after the conversion of farmland to farmland in Xiannangou river basin,were analyzed.Based on the land use situation in 2015,the expanded CA model was used to model and analyze the land use.The purpose of predicting land use types in 2025 is achieved.The main work and research results of this paper are as follows:(1)According to the research needs,the remote sensing images and topographic maps and other related data of Xiannangou river basin,before and after the conversion are collected,and the general situation of the study area and the related theories,methods and models of land use dynamic changes are introduced.So that the later research has the data foundation and the technical guarantee.(2)Using ArcGIS software to fuse and overlay the present data of land use in different periods,derive the area of different land use in different periods,focus on the dynamic degree of land use,combined with the related land indicators;For example,relative change rate,transfer matrix and so on,the temporal process and spatial pattern of land use change before and after farmland conversion in Xiannangou river basin were analyzed.It is considered that the policy of returning farmland to forest accelerates the circulation of land use in Xiannangou river basin,and changes the circulation relationship among various land uses.(3)Combining with several modeling criterions of Geo-SOS software,this paper selects the relative models of land use dynamic change,and discusses that the land use change of Xianangou river basin,in 2015-2025 will continue to keep the trend after returning farmland to farmland.After that,the change trend of land use in Xiannangou river basin,will continue to be the same as that after returning farmland to farmland.With the gradual deepening of the conversion of cropland to forest project,this change trend will become smaller and smaller,and eventually forest,grassland,arable land and other land use areas will be in a dynamic balance,and basically keep stable.