Research On The Delimitation Of Urban Growth Boundary Oriented Towards Extensions And Constraints In Mountainous Cities And Towns

High-speed urbaniz ation is a necessary part of China's modernization.However,the extensive development pattern also brought about the disorderly expansion of construction land.A large number of problems such as the occupation of cultivated land,environmental destruction,and energy waste have pose a great threat to the sustainable development of cities.Improving the efficiency of land use and managing the expansion of urban space have become very important topics at the moment.The urban growth boundary,as an important means of urban spatial growth management,can scientifically and effectively coordinate the contradiction between urban expansion and ecological resource constraints,and how to define the urban growth boundary becomes the key to the transformation of urban development from the growth of quantity to the improvement of quality.However,the specific contradictions and problems faced by different types of cities are different.There is no method for delineating the growth boundary applicable to all cities,especially the mountainous cities and towns where the tensions between people and land are more intense and environmental issues are more acute attracts less attention.The expansion of land for urban town construction in mountainous areas has its own features.Therefore,based on the dual orientation of urban expansion demand and ecological resource constraints,this paper attempts to propose a method of delineating the growth boundary applicable to mountainous cities and towns,aiming at providing a certain reference for delineating the growth boundary of mountainous cities and towns.This paper is divided into three parts in accordance with the logic of "put forward problem——analysis problem——solve problem——evidence verification".The first part is Chapter 1 and Chapter 2 of the dissertation.This part fully expounds the background and significance of the dissertation's topic,scrutinizes the research ideas and framework of the dissertation,and defines the main concepts of the dissertation through literature research.It also summarized and reviewed the relevant theories and research progress of urban growth boundaries at home and abroad.The second part is the main research content of the thesis.Based on summarizing the trends and characteristics of urban land expansion in mountainous areas,a model for demarcating the growth boundary of mountainous cities and towns based on the dual orientation of urban expansion demand and ecological resource constraints is proposed,which contains the rigid growth boundary and the elastic growth boundary.The third part is an empirical case study.First,it analyzes the expansion characteristics of construction land in Xianfeng County and summarizes the spatial growth dynamic mechanism of Xianfeng County.Based on this,it uses the model proposed above to delineate the rigid growth boundary and the elastic growth boundary of Xianfeng County.By comparison with the comprehensive plan of Xianfeng County,providing an useful reference for the planning approach of space management of mountainous cities and towns.