Study On The Relationship Between Urban Land Price And The Types Of Urban Land Spatial Expansion Identified By Convex Hull

Urbanization is the important indicator of national economic development and social progress, urban expansion is an important index of the urbanization level and the urbanization performance in space. Along with the accelerated process of our country urbanization, the urban expansion will inevitably lead to lots of arable land reduce, cause the land utilization and the land covering immense changes, therefore the urban land spatial expansion gradually becomes the hot spot which the domestic and foreign scholars pay attention. With the land market's consummation, as "the barometer" of supply-demand and changes of land market, land price is playing a significant role in affecting the spatial expansion of urban land. Further study on the internal relationship and the mechanism of urban land price with the urban land expansion, it would give full play to regulation of price level, optimize the land use structure and spatial arrangement, improve the level of intensive utilization of urban land and maximize utilizing efficiency of urban land to achieve the scientific and rational development of the city.This article relies on the State Natural Sciences Foundation Project "Research on rational urban land-use scale based on the spatial and temporal variation of urban land price level" (NO.40871053). The research area is within Shijiazhuang, on the basis of urban land price and land use related theory, taking 2000 as the base period, Shijiazhuang land prices index in 2000-2009 is estimated and its change tendency and the reason are analyzed By introducing convex hull principle, in accordance with the convex hull algorithm, using the ArcGIS software, the convex hull of the 2000 year's built-up district outline of the Shijiazhuang is constructed, and the types of urban land spatial expansion of 2000-2009 year are distinguished. On this basis, with the help of SPSS statistical analysis software to establish coupled model between urban land price and the types of urban land spatial expansion, reveals the interior between the urban land price and the types of urban land spatial expansion, which provides the basis for land price to play its role during expansion of land space.The results show that:(1) The Shijiazhuang urban land price level is an upward trend. The integrated land price, commercial land price, residential land price and industrial land price are increasing year by year. The urban land price respectively increased from 901 yuan/m2,1314 yuan/m2,919 yuan/m2,470 yuan/m2 in 2000 to 1258 yuan/m2,1746 yuan/m2,1330 yuan/m2,667 yuan/m2 in 2009.(2) The Shijiazhuang urban land price index is an upward trend. The urban land price index changed gently from 2000 to 2005. From 2006, the urban land price index increased rapidly, especially the industrial land price index growth is the biggest. The change tendency of the integrated land price, commercial land price and the residential land price were extremely similar.(3) The types of urban land spatial expansion of Shijiazhuang first are infilling, then extension. The main is infilling. The types of urban land spatial expansion is the "infilling" type in 2000-2007 and the "extension" type in 2008 and 2009. The infilling area is much larger than the extension area in 2000-2005. Although the infilling area minus the extension area was increasing year by year, the rate of increase steadily sank down. From 2006, the infilling area minus the extension area reduced, the infilling area and extension area is balancing. The infilling area minus extension area declined year by year in 2006-2009. Until the infilling area was smaller than the extension area, the type of urban land expansion has tended to the extension type.(4) Residential land price has the close relations of the types of urban land spatial expansion. The residential land price index and the extension were prominently in land expansion, is 0.924. Underθ=0.01 fiduciary level, residential land price and the urban land spatial expansion is establishes coupled model of the residential land price index and the types of urban land expansion:Y=-0.04Χ2+10.911Χ-697.80.With the increase of residential land price index, the proportion between the extension and the expansion also shows the trend of growth. And then it will reduce after growing to some extent. The urban land spatial expansion is characterised by a recycling process of infilling-extension-infilling. The change of residential land price has an important regulative function on the types of urban land spatial expansion.