A Study On The Definition And Spatial Expansion Of Urban Fringe Basing On Land Use

The urban fringe area is a transitional zone between the urban built-up area and the vast rural area,which is formed under the influence of the diffusion of urban factor.It is not only different from urban built-up area,but also different from rural area,it is also a region with drastic changes and rapid development in the city.At the same time,the urban fringe has the characteristics of transition,duality,dynamic,complexity,etc.,and it has its unique characteristics in the economic,social and ecological aspects in the process of Urbanization.Therefore,defining the scope of the urban fringe and studying the spatial change of the urban fringe and its influencing factors is of great significance for the sustainable development of the urban fringe.In this paper,taking Changan District as an example,using the three remote sensing images of the year of 2004,2009,2014 as the basic data of the study,getting the map of land use in different periods by the software of ENVI and ArcGIS,determining the urban fringe of by the method of quantitative analysis,basing on the result above,discussing and analyzing the expansion and evolution of the urban fringe in Changan District from the aspects of the general characteristics of land use change,the expansion intensity,the building density,the direction of expansion and the expansion mode.The conclusions of this paper are as follows.(1)The intensity of construction land expansion in Changan District shows obvious regional differences;the expansion of construction land has obvious directivity;the proportion of high density area is increased year by year,while the low density area showed the opposite trend.(2)The land use in the urban fringe of Changan District is characterized by three types of land use types,which are rapidly driven by the economy,the staggered distribution of construction land and agricultural land,and the contradiction between the man and the land use.(3)The influence factors of land use in Changan District are economic growth,population growth,transportation,natural environment and planning factors.(4)Puting forward four suggestions for the optimization of the structure of land use in Changan District:handle the balance between the city planning and land use planning,scientific the planning of land use,strengthen the city fringe planning dynamic,strict supervision of the land market and strengthen the monitoring of land use.