Study On Expansion Of The Urban And Delimiting Of The Urban Development Boundary Based On MCE-CA Model

Urban development boundary has become successful means and tools to control city sprawls and curb urban spread disorderly in many countries,which is of great significance to optimize the urban space layout.At present,China is in the exploration stage of the urban development boundary,and there is little research on the oasis city in the northwest arid region.Therefore,in this paper,Jiayuguan City,a typical oasis industrial city in arid region,Gansu Province,northwest China,was selected to study the urban expansion change law from 1995 to 2014 and the delimitation of urban development boundary by 2020 and 2030 with the MCE-CA model of geographic optimization simulation system(Geo SOS)based on multi-temporal Landsat data,finally discussed the related problems of the urban development boundary.The aim of this study is to provide basis for the land use and urban management of Jiayuguan.Following conclusions can been concluded:(1)During the research of 20 years,Jiayuguan city expanded rapidly,the urban land area in 2014 was 2.1 times as big as that in 1995,urban land area increased by49.50 km~2,the annual average expansion speed was 2.48km~2.a-1,Jia Yuguan city urban land characterized by rapid growth in time dimension.The compact degree of urban land and patch density was less than 1,compactness increased after the first decreases,and patch density increased,reflected the urban land connectivity and urban landscape pattern continuity increased.And the gravity center of Jia Yuguan city mainly transferred to the southeast and northwest,extension bearing index were24.61 and 17.17,transfer distance was 1141.77 m,non concentric circles of the urban expansion showed obvious expansion and orientation differentiation characteristics.(2)Applying the MCE-CA model,integrated "planning" and "anti-planning" concept,to explore delimiting the flexibility of Jiayuguan city in 2020 and 2030,the flexible urban development boundary will be 106.78km~2 and 149.35km~2,respectively,rigid urban development boundary will be 246.92km~2.(3)The urban development promoted the urban land compactness and connectivity of Jiayuguan city,the compact index increased by 0.04 and 0.06,theurban land patch density reduced to 0.04 and 0.02,patch density index fell by 0.05 and 0.07,tend to be more compact urban development,which will optimize the urban space layout and curb the spread of urban development trends,meet with the requirements of eco-city construction.(4)In terms of limit,the urban development boundary of forward period should be in 2030,the recent deadline for 2020;In terms of boundary cohesion,discussed the relation between the urban development boundary and the General Land Use Planning,the City Master Plan,the Major Function Oriented Zoning and ecological function planning;Segmentation in the aspect of legislative status,suggesting to break the presented management mechanism,to form the control laws,regulations and development license system of the urban development boundaries.