Research On Predicting The Scale Of Urban Construction Land Expansion In Changsha Based On BP Neural Network

Urban construction land is directly related to the reasonable layout and optimal utilization of land in the process of urbanization, and it has an important influence on the city’s competitiveness and development. With the rapid social and economic development and the improvement of urbanization level, the demand for urban construction land will continue to increase, and the acceleration of urban construction land expansion has become an inevitable trend. Taking Changsha, a demonstration area for resource-conserving and environment-friendly society in the rapid development of urbanization as the research object, a study on scientific prediction of urban construction land is of great theoretical and practical significance to improve the utilization efficiency, rational planning and layout of urban construction land and promote the development of two-oriented society of Changsha.Selecting the data of statistical yearbook dated from 1985 to 2013 on Changsha’s urban construction land and social and economic related date and based on the analysis of the present situation of construction land, the paper adopts nine driving factors that result in the change of construction land, and finally three major driving factors are screened out:the floor space completed, non-agricultural population and bus mileage.Based on this, Matlab software platform is used to build BP neural network model, a model that has highly precise prediction on the scale of urban construction land and a prediction is made for Changsha’s urban construction land area from 2016 to 2020, the results of which are as follows:503 km2 in 2016,539 km2 in 2017, 572 km2 in 2018,608 km2 in 2019 and 643 km2 in 2020. New construction land and the expansion rate present an increasing trend, with an average of expansion of about 35 km2 year by year. The results generally reflect the trend of demand for land against the background of social and economic development and can be adopted as reference to revise the quantity demanded for urban construction in Changsha’s urban planning.