Research On The Interaction Mechanism Between Land Price And Urban Spatial Expansion

With the process of industrial revolution, urban footprint increased day by day and the velocity of urbanization accelerated significantly. In less than a century, Shijiazhuang has become a large city with a population of 2,407,200 (2008) from a small village.With the accelerated development of urbanization, urban land spread rapidly, and land resources especially cultivated land were consumed increasingly enormously. The cultivated land occupied by new construction land reached to 3681.55 hectares in Shijiazhuang city from 2000 to 2008, while intensive utilization of land resources was low in inner city and extensive waste phenomenon was still serious. In order to avoid the disordered blind expansion, we need to analyze the influencing factors of urban spatial expansion. Urban land price, as a lever of adjusting land market, has an important influence on urban spatial expansion, but the interactions between the two were not clear. Based on this, the research probed into the interaction mechanism between land price and urban spatial expansion, in order to provide reference and help for the government to formulate practical land price adjustment principles and policies, and to improve urban land utilization efficiency.Based on the national natural science fund "research on rational urban land scale based on the spatial and temporal variation of urban land price" (40871053), the paper took Shijiazhuang City as study area, using IDL programming and linear regression analysis, calculated annual change rate of commercial land price and land expansion intensity one by one pixel, and discussed spatial variation regularity between commercial land price and urban land expansion through layer superposition. Through the introduction of land price index and relative annual expansion rate, by the least square method, analyzed the correlation of land price and urban spatial extension intensity from 2000 to 2008, and revealed the interaction mechanism with typical sample point.The results show that:(1) From the perspective of time, commercial land price presented the overall rising trend, with local negative growth, and the range of prices were 375 yuan, fit the speed of regional economic developments. From the perspective of space, commercial land price change presented divergence pattern, center stated in the intersection of construction street. Commercial land price change speed is different in different districts, affected by traffic, plan and policy, land price rose quickly in the Midwest and southeast; influenced by green ecological construction, land price increased slightly in the west and northwest; and it declined slightly in the east, the southwest and north because of poor infrastructure.(2)From the perspective of time, Land price showed overall slow growth trend, presented slow growth, accelerated growth, sustainable growth and decelerated growth four states. From the perspective of space, the form, characteristics and performance extended direction of urban land were different in different stages. Before 2002, it mainly developed in the south, of semiorbicular state. It began around denotative development within Second Ring from 2002 to 2004. From 2004 to 2007, it expanded greatly in all the directions except the southwest, especially the southeast. From 2007 to 2008, it expanded with circinate state, and east of Beijing-Zhuhai expressway developed fastest.(3)In Shijiazhuang national hi-tech industry development zone (hereinafter referred to as the "east zone") and southeast of the Yuhua District, land price and urban spatial expansion presented obvious positive correlation, and it was negative correlation in the surrounding scattered areas. Through typical sample point verification, urban expansion pulled land price increasing in "east zone", southeast of the Yuhua District and north of urban land(typical representative sample points for A, C, E), with time difference about one year. In the east and southwest (typical representative sample points for B and D), urban expansion speed was slow, land price rise or slow down slightly, with not obvious correlation.