The Analysis Of Urban Expansion And Driving Forces Of Nanchong City Based On Remote Sensing

The city,which is one of the important places of human habitat,is the main component of human civilization.With the development of human civilization,it is also the exchange place of various substances,information,and energy on the surface.Urbanization,which means a large population entering the city,is a process in which the population increases rapidly,leading to the lack of the existing urban space,and the scope of the city expands gradually.With the continuous acceleration of economic globalization,the global urbanization and the urban system are transforming and reconstructing.The urbanization of the developed countries has basically entered the mature stage.The development of urbanization has shifted into the developing countries;especially the way of Chinese unique development of urbanization has attracted wide attention.The factors such as economic rapid growth and globalization of China have convenient the life and transportation,develop the education as well as improve the infrastructure constantly in urban.In pursuit of better quality of life,a large number of rural population come to the city which causes the lack of space,as a result,the expansion of urban space is necessary.Under that circumstance,it has a huge impact on city's construction and development,and the ecological environment.And a series of problem have appeared.Therefore,the study of urban expansion is one of the hot spots of current researches.The use of traditional urban land scale statistics to monitor the expansion of the city can't meet the current needs,so it is the top priority to use scientific and technological means to monitor urban development.Nowadays,with the rapid development of geographic information system and remote sensing technology,we can quickly grasp information of the use of urban construction land through the study of the urban development by the interpretation of aerospace remote sensing image,and the information which can help us make real-time assistant decisions for our control to the size of urban construction.Nanchong,a city of Sichuan Province,is the research object in this paper.The domestic and foreign research results is collected first to study the city's expansion and its driving force mechanism.By using satellite remote sensing data of 2000,2005,2010 and 2015 as the main data source,Under the support of Nanchong Statistical Yearbook data,ARCGIS,ENVI and other software,it analyzes the dynamic changes in urban expansion and reasons of promoting the expansion in the main urban districts of Nanchong.The followings are mainly parts in this paper:(1)The information extraction of the extension of urban land.In this study,at first,it uses four-stage satellite remote sensing images to process geometric correction,cut the research area,and enhance the image and other preprocessing images.Then the supervised classification and unsupervised classification based on the maximum likelihood method to extract the information of the expansion of urban outer contours are applied.At last,it contrasts and analyzes the information.(2)Studying the spatial and temporal changes in urban expansion.It analyzes the change of expansion area,the change of form and space,and other aspects in urbanization area in Nanchong to study the index of the urban expansion's speed,direction,the compactness,etc.(3)The study of dynamic mechanism in urban expansion.The research is processed from the natural geographical conditions,economy,transportation,population,urban planning and other aspects of Nanchong to study the driving force of expansion.From the research,there comes to be the following conclusions:(1)Using the supervised classification and the unsupervised classification based on the maximum likelihood method extract the external boundary of urban expansion in Nanchong.The results show that the supervised classification is the better way to extract the boundary of urbanization area.(2)From 2000 to 2015,the urbanization area of Nanchong is expanding,and the center of expanding is changing from south to north,and then from north to south.(3)According to the speed and intensity of the expansion of the urbanization area in Nanchong,the speed and the intensity have been slowed down which indicates that the urban expansion of Nanchong has been gradually stabilized.(4)The driving factors of urban expansion mainly include physical geography,rapid economic development,population size,the degree of complete transportation infrastructure,urban master planning...