Research On Delimitation Of Urban Growth Boundary Based On Bigdata ——Take Yongding District Of Zhangjiajie City As An Example

In recent years,with the rapid development of urbanization in China,all kinds of production factors are rapidly concentrated in cities and towns,resulting in the disorderly spread of cities,which brings great challenges to China’s ecological environment,resource conservation and sustainable development.At the same time,the progress of all kinds of data collection technology provides a new perspective for us to study the new urbanization development mode.At present,China’s land and space planning is developing vigorously.The focus of China’s urban construction has shifted from the previous "increment" to the "stock" as the core.At the same time,the pursuit of urban-rural integration and overall development puts forward higher requirements for the quality of China’s urban construction.The application of multi-source data in urban and rural planning and the planning ideas of "ecological priority" and "smart growth" contained in urban growth boundary have been widely used in improving urban quality and coordinating the contradiction between city and environment in foreign countries.In China,how to combine multi-source data with urban growth boundary,more scientific and reasonable delimitation of urban growth boundary,make it in line with the ecological environment protection at the same time,promote the orderly growth of the city,has become an important problem.In this study,Yongding District of Zhangjiajie City is taken as the research goal,and the realization of ecological environment protection and urban orderly expansion is taken as the research goal.Based on the NDVI data,NPP data,spatial distribution data of soil geology,rainfall data,evapotranspiration data,night light data,POI data,land use and remote sensing images of Yongding District in 2010,2015 and 2018 This paper interprets the data and socio-economic data,and studies the delimitation of urban growth boundary in Yongding District from two aspects of ecological importance and urban construction suitability.Firstly,from the "ecological background",based on the evaluation results of the importance of ecological protection in Yongding District of Zhangjiajie City,the "rigid" urban spatial growth boundary is defined.On the Arc GIS software platform,the importance of water conservation,the importance of soil and water conservation,the importance of biodiversity maintenance function and the sensitivity of soil and water loss in the study area are carried out by using the dual evaluation method of land and space In addition,the evaluation results are divided into five grades: extremely unimportant,unimportant,general,important and extremely important.The important and extremely important regions are divided into rigid urban growth boundaries.Secondly,from the perspective of "orderly urban expansion",this paper selects the driving factors affecting urban development and construction,including topography,distance from urban area,distance from main roads,regional POI density,regional night light index,etc.,and then uses mce-ca model in geosos software to simulate the land use of urban built-up area in 2030,so as to delimit Yongding District of Zhangjiajie City The "elastic" boundary of urban spatial growth.Finally,the rigid urban growth boundary and elastic urban growth boundary are superposed and analyzed in Arc GIS software to get the final delimitation result.At the same time,the delimitation results are compared with the "Zhangjiajie City Master Plan（2007-2030）".From the perspective of the implementation and fine management of growth boundary,the corresponding control strategies are proposed according to the research results of this paper.Combined with the land supply and demand regulation methods,some suggestions and inspiration are provided for the implementation and management of urban spatial growth boundary in Yongding District.