Study On The Population Change Of County-level Cities Based On Urban Construction Land Differences

With the rapid development of urban economy,the population keeps gathering in cities to accelerate the urbanization development process,so as to continuously expand the scale of cities to carry more population and industry.The rationality of urban land structure layout is the key to the development process of urban land.In order to explore the relationship between urban land use and population change,reasonable planning of urban land use layout combined with the actual situation of population change is essential to improve the adaptability of urban land use and population development.There are 394 county-level cities in China.From 2010 to 2020,the Ministry of housing and urban rural development of the people’s Republic of China released data related to urban construction land and population of 374 county-level cities.Due to a large number of data missing values in some cities,taking into account the continuity and integrity of data,180 county-level cities in China were finally selected as the research object to carry out research from three aspects: urban construction land difference,population change and their correlation.Based on fuzzy comprehensive evaluation method and fuzzy centroid method,a city type evaluation system of county-level cities is proposed to realize the comprehensive evaluation of construction land of county-level cities.180county-level cities belong to the overall distribution of membership degree of different city types,and the county-level cities are divided into residential type by K-means clustering Based on this,the differences of urban construction land in the development process of county-level cities are revealed.In order to study the population changes of county-level cities,firstly,the least square method is introduced to put forward the population change curve fitting algorithm to describe the population data changes of county-level cities under the background of sampling survey.Secondly,according to the six population changes in2010 and seven population changes in 2020 Population change data is obtained by revising the fitting curve of population change under the background of sampling survey based on population change data of census statistics Finally,t test is used to verify the difference level of population data under different statistical backgrounds,and the actual situation of population change in county-level cities and the difference of demographic data under different statistical backgrounds are obtained.Build the prediction model of population change in county-level cities based on BP neural network,study the difference of urban construction land and population change in county-level cities,predict the urban population change with the membership value of county-level cities belonging to different city types,explore the correlation degree between urban construction land and population change in county-level cities,and realize the research of population change in county-level cities based on the difference of urban construction land.The main conclusions are as follows: there are certain deficiencies in the statistical data of urban land use and population of county-level cities in China,and the statistical data are not comprehensive enough as a whole.The proposed city type evaluation system can realize the comprehensive land use evaluation at the county level and obtain the distribution of membership degree of different city types at the county level.Of the 180 county-level cities,132 cities can be expressed by the population change curve under the census statistical caliber.Only 34 cities have no significant difference under the census statistical caliber and population sampling survey statistical caliber.The correlation between urban land use and population development in county-level cities is not strong,so it is not perfect to analyze the change of urban population by using urban land use development.Grasping the development trend of urban land use in county-level cities,improving the accuracy of population statistics and rationally planning the layout of urban land use are the keys to maintaining the sustainable development of cities.