Simulation And Regulation Of Urban Inertia Space Under The Constraint Of Basic Farmland

With the accelerated process of industrialization and urbanization,over 10 million of the annual and nearly 300 million of the total population which is equivalent to the number of population in the US and two sizes of Japan transferred to the cities and towns to settle,it will bring short-term rigid demand for urban space expansion,and the widespread failure cases of stern containment of urban expansion at home and abroad,indicating that the inertia of urban expansion driven by rigid demand is difficult to contain;at the same time,the food security of China’s nearly 1.4 billion population also has a long rigid demand for agricultural land resources,especially basic farmland.Therefore,the superposition of two types of rigid demand for urban space expansion and basic farmland protection will bring unprecedented pressure and challenge to the simulation and control of the urban inertial space.In view of this,on the basis of improving the traditional "containment of expansion" hypothesis,this paper puts forward a new paradigm of "reserved space" in the future urban expansion and takes Xuzhou City as an example.According to the logical thinking of "theoretical analysis-empirical study-prediction regulation" and the main research line of "problem presenting-problem analysis-problem solving",comprehensively appling the methods of spatial recognition,system simulation and equilibrium analysis,based on the land use pattern change and scientific classification of basic farmland to identify the urban status boundary,in order to predict the urban expansion inertia space under the constraint of basic farmland.Finally,different types of reserved space are determined from the perspective of value equilibrium and corresponding regulation suggestions for different types of reserved space are proposed.The main conclusions of this paper are as follows:(1)The area of construction land in the study area continued to increase during the period from 2005 to 2015.The construction land increased from 2005 to 2009 mainly came from forest land,and from 2009 to 2015,it mainly came from cultivated land;the patch shape of each land use type is less complex,and the landscape of the overall area has strong stability and appropriate diversity;the main direction of the increase in construction land is northeast and east,during the period of 2005-2009,the area of construction land increased to the northeast and east respectively accounted for 22.62% and 22.55% of the total increase area,and it increased to 28.45% and 26.95% from 2009 to 2015.(2)Through the establishment of the basic farmland demarcation index system and the entropy method and the analytic hierarchy process,the indices such as natural quality,utilization quality,economic quality,spatial connectivity,traffic conditions,distance from the town,distance from the village are calculated,the comprehensive weights of the indicators are 0.17,0.29,0.18,0.22,0.04,0.07,and 0.03;the final area of basic farmland in the study area is 1306.75 km2,including 990.97 km2 in Tongshan District,291.79 km2 in Jiawang District,11.76 km2 in Gulou District,9.62 km2 in Yunlong District,and 2.61 km2 in Quanshan District.(3)Analysis of urban built-up areas in 2005,2009 and 2015 revealed that the growth direction of urban built-up areas was mainly in the east and southeast from 2005 to 2015,of which the urban built-up area increased by 2906.29 hm2 to the southeast and 2749.93 hm2 to the east from 2005 to 2009,and an increase of 2000.56 hm2 in the southeast and 2087.05 hm2 in the east during the period from 2009 to 2015;the accuracy of land-use changes simulated by the CA-Markov model is high,and the simulation shows that the inertial range of urban built-up areas in 2020 is still mainly east and southeast compared to that of 2015,with a total area of 17,807.82 hm2.(4)Estimated that the economic value,ecological value,social value,and farmland comprehensive value of agricultural land in 2006-2016 are all shown to increase year by year.In the comprehensive value composition of farmland in the past years,the proportions of economic value,ecological value are between 33.38-44.84%,12.73-23.85%,and 40.45-46.00% respectively;the grey forecasting models for economic value,ecological value,and social value of farmland can all pass the test,predicting three types of farmland in 2020,values were 7.1895 million yuan/hm2,2.1177 million yuan/hm2 and 7.1380 million yuan/hm2 respectively,and the comprehensive value of farmland was 16.3210 million yuan/hm2,the combined value of the three kinds of farmland accounted for 44.05%,12.98% and 42.97%,respectively.It is expressed as economic value> social value> ecological value.(5)Judging from the point of view of the value of construction land and agricultural land,three types of urban expansion control reserved space are: the ideal reserved space when the price of agricultural land can fully show the true value of agricultural land,with an area of 9290.95 hm2;sacrificing the social value of agricultural land can reserve space for the cost of urban expansion,with an area of 1,364.33 hm2;in the case of considering only the economic value of agricultural land,sacrificing its social value and damaging its ecological service function,it can provide space for the expansion of urban expansion,with an area of 491.75 hm2.It is suggested that the adjustment of the urban expansion inertia range in the cost reserve space of 1364.33 hm2,and is a win-win strategy to achieve urban development and farmland protection in Xuzhou.