The Research Of Spatial Expansion And Influencing Factors For The Main City Of Jinchang

Jinchang is a typical resource-based city located in arid zones.In this paper,through the collation of related literature,Landsat remote sensing image classification and extraction as the main means of data acquisition,in ArcGIS10.2 on the six data space superposition analysis,obtained the central city expansion vector,through the intensity of urban expansion With the calculation of the elasticity coefficient,the center of gravity shift and the direction of the expansion,the rationality and the distance differentiation of the urban expansion are analyzed by comparing the velocity,the compactness and the fractal dimension,and the analysis of the urban expansion.The calculation of public boundary method,the study of Jinchang City expansion model.Combined with the specific situation of Jinchang City,from the natural and human factors to analyze the driving force of urban expansion.The main conclusions of the paper are as follows:(1)Jinchang city space has experienced from slow to medium speed expansion,to high-speed expansion and then fall back to the rapid changes in the process.Two thousand years ago,the city is west,northwest,northward expansion is faster,southeast,south,southwest,east direction expansion is slow,causing the urban spatial center of gravity to the northwest offset,and the offset distance is small.After two thousand years,in addition to the east,southwest,southeast,northeast direction to expand faster,the other direction of the city are slow to expand,causing the city center of gravity to the southeast direction,backward to the northwest,with the 1987 center of gravity Compared to still in the east direction.The analysis of the spatial expansion intensity of Jinchang city shows that with the increase of the distance from the central city,there is a decreasing spatial distribution.(2)The compactness index and fractal dimension of Jinchang urban spatial form show the opposite trend,and the urban compactness index is decreasing and the fractal dimension is on the rise.During the whole study period,the expansion type of Jinchang city is mainly extrapolated,accounting for 52.66%,which indicates that the city is in the stage of rapid outward expansion,and the corresponding fractal dimension has been decreased.Secondly,it is filled,accounting for 30.32% Jumping,accounting for 17.03%.(3)In the course of nearly three decades of urban development,the expansion of built-up areas mainly occupied unused land,followed by rural settlements and other construction land,grassland,woodland and arable land occupied less;Gobi beach,sand,bare land and other unused land is gradually being developed for a large number of urban construction land.(4)Jinchang due to mine built,due to mine and Xing,therefore,the advantages of resources is the premise of the city,natural factors become the constraints of urban development.The adjustment of industrial structure,economic development and population increase is an important driving force for the expansion of urban space.Government policy guidance and urban master planning on the direction and pattern of urban extension have a decisive impact,and Jinchuan company to help the city development,Jinchang City is the main driving force of urban expansion.