The Spatio-temporal Evolution Of Urban Land Expansion In Huaihai Urban Agglomeration And Its Impact On The Balance Of Cultivated Land

With the continuous progress of land urbanization in China,a large number of cultivated land resources are reduced by the impact of urban land expansion,which further aggravates the contradiction between cultivated land resources protection and urban construction site expansion.On the basis of ensuring food security,how to meet the demand of urban land expansion,realize the efficient use of land,and promote the healthy and sustainable development of urbanization has become the key content of urban land expansion research in China.In recent years,the state attaches great importance to the coordinated and sustainable development of urban agglomerations,and clearly points out that the inter regional urban agglomerations should be taken as the main body of the new urbanization development,so as to strengthen the coordination of the integrated development of urban agglomerations.At the same time,we should improve the balance system of cultivated land occupation and compensation,and protect the cultivated land resources while the process of land urbanization continues.Therefore,it is very important to further coordinate the contradiction between urban expansion and cultivated land protection by deeply studying the spatial-temporal evolution process and driving factors of urban land expansion,predicting the scale and spatial pattern of urban expansion in the future,and exploring the impact of urban land expansion on the balance of cultivated land occupation and compensation.Based on the data of social economy,land use and basic geography,this paper uses the methods of spatial analysis,geographic simulation and scenario analysis to analyze the spatial-temporal characteristics,driving mechanism and urban land expansion of Huaihai urban agglomeration Zhang made a comprehensive and systematic study on the impact of the balance of farmland occupation and compensation.The main conclusions are as follows:(1)The spatial pattern of Huaihai urban agglomeration has not yet been formed.The urban land is distributed in a multi-core and decentralized way,showing a spatial pattern of "core periphery" sprawl.There are significant differences in the scale of urban land among cities,and the scale of urban land basically corresponds to the order of economic development level.In the direction of urban land expansion,the overall expansion intensity of Huaihai urban agglomeration is more balanced than that of urban scale.On the scale of cities,because of the better urban foundation in the central area of each city,and the inherent advantages in economy,transportation and population,it is conducive to the expansion of cities and towns,so the expansion intensity of the central area is the largest in all cities.This also shows that the original urban foundation of the central city is the main driving force of urban expansion.(2)The spatial expansion mode of urban land in Huaihai urban agglomeration is mainly marginal expansion.Considering the overall and urban scale,Huaihai urban agglomeration is still in the "diffusion stage" of cities and towns.In order to improve the quality of land use and optimize the urban form and layout,Huaihai urban agglomeration should strengthen the traction of policies,actively control the phenomenon of large oneway expansion intensity of core cities,and alleviate the excessive pressure of one-way land use.In addition,the urban planning should avoid the disorderly expansion of "spreading the pie",scientifically and reasonably plan the scale and layout of cities and towns suitable for the carrying capacity of resources and environment,and promote the coordinated and integrated development of urban land expansion,economy and population.Avoid excessive development of urban land,resulting in the waste of land resources.(3)Through the systematic analysis of the spatial-temporal characteristics of urban land expansion in different development stages of Huaihai urban agglomeration,it is found that the scale of urban land in Huaihai urban agglomeration is in the stage of rapid growth,which is mainly driven by the distance from the railway,the distance to the main highway,the distance to the City Center,terrain slope and population density.In the future natural development scenario,urban land will continue to spread and expand to the periphery of the city,which will occupy a large number of high-quality cultivated land resources in the periphery of the city,resulting in the continuous reduction of cultivated land and ecological benefits.In order to supplement the production capacity loss of cultivated land caused by urban land expansion and protect food security,a variety of land development scenarios are set to supplement the production capacity loss of cultivated land.If the balance of occupation and compensation of cultivated land production capacity is realized in the future,a large number of other types of land will be occupied,which will have different degrees of impact on the future ecosystem and lead to further reduction of ecological benefits.