Study On The Boundary Demarcation Of Urban Growth Based On "Multi-Regulation And One System"

This paper analyzes the current situation of Pingxiang's population,economy and land use,as well as the difficulties faced by Pingxiang in the multi compliance.Pingxiang is in the transition period of resource exhausted cities.With the increasing ecological concept and the attention to ecological development,the model of urban space development will be expanded from disorder to compact.Based on the concept of "anti planning",it is proposed that the rigid boundary of urban growth should be delineated to restrict the unordered development of ecological destruction,and the elastic boundary of 2020 and 2025 is delimited in the light of local conditions and the actual conditions of the city.Delimitation of elastic boundaries is to distinguish urban construction land from non construction land,while rigid boundary is the bottom line for ensuring urban ecological safety.On the basis of the expansion strength index,the coordination degree of urban expansion and population elasticity index and the compactness of urban land use,the expansion characteristics of urban towns in Pingxiang are analyzed,and it is found that the urban land expansion speed,the expansion intensity,the annual average growth rate of urban land use and so on,and the population elasticity index of urban land use is increasing and More than 1,indicates that the urban land has a certain degree of waste;the economic elasticity index is increasing,which indicates that the economic benefit of urban land use is increasing,and the compactness is rising,which indicates that the expansion of urban land use is not a simple extension,and the level of economize intensification is improved.The main factors such as population,economy,transportation,natural environment and policy are analyzed,and the importance of the influencing factors is determined by the grey relational degree method,in which the total industrial output value and the urban population dominate.In addition,the urban spatial expansion pattern is mainly influenced by the natural environmental factors in the northeast east(ENE),the southeast South(ESS),and the north-west(WNN)direction.The above analysis provides conditions for theprediction of urban land scale,ecological suitability evaluation of urban land,carrying capacity of resources and environment,and delineation of urban growth boundaries.The carrying capacity of resources and environment in Pingxiang has been overloaded.With the continuous development of economy,the economic carrying population has been alleviated to a certain extent.The ecological suitability analysis of urban land use in Pingxiang city is a high suitable construction area and the high suitable construction area accounts for 39.6% of the whole city of Pingxiang,among which lotus county occupies the largest proportion,accounting for 25.39%,followed by Shangli county.The urban land use scale of 2020 and 2025 was predicted by multiple linear regression model and grey prediction model,and the final urban land use area of 12991.79 hectares and 16847.62 hectares was determined in combination with the overall land use planning,urban development planning and 13 th Five-Year planning.On the basis of summarizing the research progress of urban growth boundary at home and abroad,using the concept of "anti planning",the rigidity UGB is delimited by using the factors such as elevation above 500 meters,slope above 25 degrees,permanent basic farmland protection,ecological red line protection and high prone area of geological disasters,and the area of the rigid boundary is 6.7408.19 hectares,of which 7115.22 hectares of built-up area are not suitable for 17632.14 hectares of construction area.On the basis of the comprehensive evaluation of ecological suitability of urban land use and the carrying capacity of resources and environment by using the analytic hierarchy process(AHP),Delphi method,logistic multiple regression analysis and GIS's spatial superposition analysis function,this paper analyzes the multi situation of urban land expansion,and analyzes the development of its variable factors at high speed,medium speed and low speed.As the actual data show that Pingxiang city has got rid of the low speed and medium speed development model,it simulates the situation under the high-speed development.On the basis of the accuracy test of the neural network cellular automata,the ANN-CA model is used to simulate the urban land use scale of Pingxiang in 2020 and 2025.On the basis of selecting the simulated situation in accordance with the best development state of Pingxiang,the elastic boundary area of 2020 is 13210.38 hectares,and the elastic boundary area in 2025 is15553.62 hectares,and the reasonableness of boundary delimiting is analyzed.