Research On Demarcation Of Urban Development Boundary In Qimen County Under The Constraint Of Ecological Security

Since China entered the stage of rapid urban development,the urban scale has expanded rapidly.Along with the rapid development of cities and towns,there are also problems such as environmental degradation,waste of land resources and weakening of ecosystem services.As a concrete means to control the scale and form of urban development,the demarcation method of urban development boundary is the core content to distinguish whether the urban development boundary is reasonable and the concrete measures to solve the problems caused by urban expansion.At the same time,with the continuous strengthening of China’s environmental protection efforts and the improvement of ecological restoration measures,the development concept of "green water and green mountains are golden mountains and silver mountains" should also be implemented in the delimitation of development boundaries to further improve its technical methods.Traditional urban development boundary delimitation considering ecological constraints or just a single element such as urban spatial growth,this article attempts from the urban space growth and ecological synergy analysis Angle of view of resource constraints,and with rich ecological resources,the land use situation tense for mountain city qimen county as an example,discusses different urban development under the restriction of ecological security level boundary delimitation method,aimed at science border city development to provide certain reference.First of all,this paper reviews and sorts out the research progress of urban development boundary at home and abroad,summarizes the concept of urban development boundary,summarizes the practice of urban development boundary,sorts out the demarcation method of urban development boundary,and seeks appropriate technical path for the empirical research on urban development boundary demarcation of qimen county.That is,according to the actual situation of qimen county and surrounding environment,the constraint basis and demarcation condition of development boundary are determined.Secondly,this paper selects qimen county as the research object,and on the basis of collecting and sorting out relevant spatial data,respectively develops the construction of urban ecological security pattern and the simulation of urban land expansion based on cellular automata.Among them,the ecological security pattern ensures the living environment and migration path of wild animals with the ecological source area and ecological corridor obtained based on the path model of minimum cost.The ecological sensitivity evaluation of multi-factor grid superposition is used to control and block the urban sprawl.At the same time,on the basis of multi-department data collection,network POI,road network information crawling and spatial data sorting,the GIS model plug-in of cellular automata of neural network was used to simulate the process of urban expansion,and the land use result of urban expansion was obtained.Finally,based on the results of urban land expansion generated by cellular automata constrained by different levels of ecological security pattern,the urban development boundary plans with different levels of ecological security were obtained,and the simulated urban development boundary plans with mandatory constraints were used as the demarcation scheme of rigid urban development boundary.Based on the function positioning of qimen county as a tourist city and the development demand of qimen black tea green industry,this paper selects and optimizes the final development boundary plan of qimen county as an integrated area,in order to achieve the planning goal of ecology and development win-win.