Study On The Optimization Of Permanent Basic Farmland In Guixi City Based On Multi-scenario Land Use Simulation

Cultivated land is the cornerstone of agricultural production and the fundamental guarantee of national food security.Since the 18th National Congress,General Secretary Xi Jinping has made important instructions on farmland protection:"We must implement the strictest farmland protection system and adhere to the red line of 1.8 billion acres of cultivated land."Permanent basic farmland as cultivated land that cannot be arbitrarily occupied,reasonable demarcation of permanent basic farmland must not only meet the quantitative and quality requirements,but also alleviate the contradiction between the demand for land in urban construction and the strict protection of cultivated land in terms of layout.This study not only considers the natural endowment conditions of arable land and permanent basic farmland,but also coordinates the demarcation of urban development boundaries so that the two do not overlap with each other.This paper first comprehensively evaluates the cultivated land in Guixi City based on the"trinity"system of quantity,quality and ecology of cultivated land;then uses the FLOS model to simulate the expansion of future construction land in multiple scenarios,and combines the MCR model to evaluate the suitability of construction to revise the simulation results and delineate the urban development boundary of the research area in 2035;finally,the comprehensive results of cultivated land evaluation and development boundary demarcation are synthesized,and the ideas and methods of the optimal layout of permanent basic farmland are proposed,and the permanent basic farmland after optimization is obtained.The main findings of the study are as follows:(1)Based on the comprehensive evaluation system of"Trinity"of cultivated land,the comprehensive evaluation results of cultivated land in Guixi can be obtained directly after judging the comprehensive level of each piece of cultivated land,the quality cultivated land of Grade I and Grade II reached 87.95%of the total cultivated land area.Comparing the permanent basic farmland demarcated in 2017 with the evaluation results,it can be seen that the original demarcated results are generally reasonable,but there is still room for optimization and adjustment.(2)Based on FLUS model and land use data in 2010,relevant parameters are set according to the land use change from 2010 to 2018,and 2018 is used as the base period to verify the precision of the model,there are three scenarios:natural development,cultivated land protection and ecological control,simulating construction land expansion in 2035.Based on MCR model,the expansion simulation results were revised,and the urban development boundary area in 2035 was determined to be 97.87 km~2 after a series of treatments.(3)Adhering to the principle of"survival of the fittest",we transferred 4,872.37hectares of permanent basic farmland,which is still arable land within the boundaries of non-arable land and urban development,transferring all 6791.69 hectares of first-and second-grade arable land with potential for rezoning into and out of the same amount of third-grade arable land with a gap of more than 4872.37 hectares,which is located in the pre-optimization results and is of worse quality than the same year before optimization,the final designation of permanent basic farmland is 45120.56 hectares.Compared with the original results,the optimized permanent basic farmland improved in comprehensive scores and quality,it shows that the method of optimizing permanent basic farmland based on comprehensive evaluation and multi-scenario simulation is feasible.