Spatial Optimization Decision Support Of Cultivated Land In Rapid Urbanization Area

Cultivated land is an important land resource for human survival and it is the essence of land resources.It relates to national food security and ecological security.As the most populous country in the world,it is significant to protect cultivated land,especially to optimize the layout of cultivated land and improve the production capacity of the cultivated land system.However,due to the high overlap of high quality cultivated land resources and urban construction space,the process of urbanization in China is at the expense of high quality cultivated land,which leads to the increasingly fragmentation of the spatial distribution of cultivated land.It is seriously threatening the production efficiency and sustainable use value of cultivated land.Therefore,it is of great practical significance to coordinate the spatial conflict between the urban development and the cultivated land protection,rationally optimize the spatial distribution of the cultivated land resources in the rapid urbanization area,and realize the centralized control and protection of the high quality and high yield cultivated land resources,for alleviating regional human and land contradictions and realizing the optimal protection and utilization of land space.This paper took the area including Tianning district,Zhonglou district,Xinbei district,Wujing district of Changzhou city area in Jiangsu Province as the study area.The multi source land information such as land use change survey data,social economic statistics data and related planning materials are integrated,and the spatial and temporal evolution trend of cultivated land landscape pattern in the study area and the status of spatial management and control are analyzed.The potential conflict of cultivated land identification method based on RF-CA urban expansion model is studied.Intergrating GIS spatial analysis method,K-means++ algorithm and PCA-AHP index comprehensive weighting method to propose optimal decision-making method of cultivated land spatial optimization in patch scale rapid urbanization area.The main research contents and conclusions of this paper are as follows.(1)During 2009-2015,the cultivated land in the study area was transferred to 1824.87 ha,and 4302.11 ha was transferred out.The area of cultivated land was reduced by 2477.24 ha,and the proportion of cultivated land to construction land was 91.61%,and it was mainly around the edge of the central urban area and the surrounding area around the main built-up area.This indicates that the construction of urban expansion is the most important form of farmland conversion in the process of rapid urbanization.From the angle of landscape pattern of cultivated land,the MPS index decreased from 1.8826 to 0.9187,and the SPLIT index increased from 29.5949 to 63.1300,which showed that the fragmentation of cultivated land increased and the difficulty of space management was increased.(2)The random forest algorithm and the CA model were combined to simulate and analyze the spatial and temporal evolution of urban expansion in.the study area.The potential conflict with the cultivated land protection space by constructing the RF-CA model.Based on the confusion pixel matrix evaluation,the accuracy of the RF-CA model is as high as 0.90,which indicates that the model is effective in urban expansion simulation.On this basis,the model is used to predict the results of urban construction land use in 2025,and the spatial conflict between the results and the cultivated land is analyzed.32087 potential conflict plots are obtained,the potential conflict area is 5171.81 ha,and the area of the plot spot of the potential conflict with the basic farmland protection area is 556.40 ha.(3)Based on the analysis of potential conflicts between cultivated land protection and urban expansion,based on integrated GIS spatial analysis,K-means++algorithm and PCA-AHP index comprehensive empowerment method,the optimal decision scheme of potential conflict arable land on the scale of land is proposed.The study divided 2712 basic farmland protection spots,and 4064 construction occupancy spots.The results show that the spatial overlap of the basic farmland protection spots and the planned basic farmland protection area,the construction occupation spots and the construction land control zone are more than 80%,which can satisfy the centralized control and protection of the regional cultivated land resources and realize the region sustainable development.