Research On The Urban Spatial Development Pattern Of Chizhou City Based On The Pattern Of Ecological Security

Since the 20th century,the extensive urban expansion with economic development has brought problems such as the destruction of ecological land,the incremental development of land,and the sharp decline of biodiversity.The huge expansion of city landuse will inevitably cause the agriculture landuse,forest land and other relative landuse to be occupated,it interferes with the function and structure of urban ecosystem,and then causes a variety of serious city problems like air pollution,sharp decline of forests and shortage of water resources,etc.These problems impact the natural ecosystem and restrict the sustainable development of our society.While the development of the urban economy and society,which has gradually become a common problem all over the world is that how to make a harmonious relationships between human,society,economy and nature.The city research based on the ecological concept has gradually entered people’s vision due to solve the problem that how to realize the urban sustainable development during the fast urbanization period.According to the development concept of paying equal attention to ecology and development of rational use of land resources and urban construction in line with local conditions,this paper discusses how to scientifically and appropriately determine the scale and form of urban development through the framework of ecological security pattern,and strengthen the importance of ecological environment protection in urban development,so as to realize the coordinated urban spatial development pattern of ecological environment protection and developmentThis paper selects Chizhou as an example which is a representative city locates in southern Anhui Province,to carry out empirical research.Chizhou City has superior ecological environment conditions and geographical advantages near the Yangtze River,and by constructing an ecological safety pattern to speculate the best spatial development pattern of the city,it is more scientific,integrative and systematic than the traditional study of urban spatial development pattern,and it is more idealistic to determine the urban spatial development pattern with protecting the ecological security,thus make the paper is capable of the theoretical and practical meaning.Firstly,this paper searches,and summarizes both the domestic and abroad literatures about ecological security and urban spatial development pattern,and reviews the existing research on correlative theories,and raises the research means of urban spatial development pattern based on ecological security pattern.This paper discusses the theories of ecological security,electric circuit theory,harmonious relationship between human and land theory and sustainable landuse theory,studies the relationship between"ecology-human-social development",understands the supporting capacity of ecological environment for urban development,evaluates the ecological sensitivity and ecological network of Chizhou City,and finally superimposes the evaluation results.From the perspective of supply to consider the restrictive factors of urban development,and classifies the results,analyzes the results and choose the best urban spatial development pattern of Chizhou City,this progress can solve the problems between resources,environment,society,human and development correctly,and it can realize a harmonious relationship between the protection of ecology and the development of city construction.The conclusions of the paper are as follows:(1)In the ecological sensitivity evaluation of Chizhou City,five major factors were selected for analysis:watershed,elevation,slope,geohazard and normalized vegetation index.and the results of each type of factor evaluation are weighted and superimposed to obtain a comprehensive ecological sensitivity evaluation map of Chizhou city.Based on the results,it can be seen that the ecological sensitivity of Chizhou City in the southeast is higher and in the northwest is lower,and the highest ecological sensitivity in the southeastern part of the middle mountain topography landscape,with an area of about 648.24 km~2,and lower in the plains and alluvion flat and polder terrain in the north of the city,with an area of about 1822.28 km~2.(2)In the ecological network analysis of Chizhou City,the inverse granularity method is used to determine the ecological source sites.By analyzing the landscape connectivity index,it can be seen that 400m particle size is the best criterion for selecting ecological source sites in Chizhou City.The resistance value in Guichi,Yaodu,Dadukou,Xiangyu,Rongcheng,Miaoqian is higher.According to the circuit theory,Linkage Mapper software was used to calculate 315 key ecological corridors and 41potential ecological corridors in Chizhou City,with a total of 146.81 km of key ecological corridors and 237.99 km of potential ecological corridors,while identifying the corridor centrality and ecological obstacle areas,and obtaining 35 ecological obstacle areas in Chizhou City.The ecological corridors were analysed as buffers and overlaid with ecological resistance surfaces,ecological bstacle areas and nature protection zones,and this paper divides the results of the ecological network analysis of Chizhou City into six categories,assigned the values 1,3,5,7,8 and 9 in turn.(3)Overlaying the ecological sensitivity result and the ecological network result ofChizhou City,then normalize and reclassify the overlaid result into four categories:high ecological safety pattern area,medium ecological safety pattern area,low ecological safety pattern area and other areas.Due to the principle of FLUS model,and this paper uses the scenario analysis method,in Geo SOS-FLUS software,the urban spatial development pattern of Chizhou City under different ecological security patterns is simulated,and the urban spatial development pattern of Chizhou City in 2030 under natural condition,low ecological security condition,medium ecological security condition and high ecological security condition are obtained.Analysing the land use and urban expansion of the four simulation results,it is concluded that the ecological security pattern is the best choice for the urban spatial development pattern of Chizhou City.