Kunshan City Spatial Expansion And Its Smart Growth Strategy Study

In recent years, the acceierating urbanization process leads to significant urban land use growth and rapid spatial expansion. Kunshan,as a typical city in developed area, its model of urban spatial sprawl based on land expansion encouraging economic development can't adapt to the urban sustainable development. "smart growth", as a new concept of urban development to control the urban disorderly sprawl, has a significance in guiding in exploring a strategy of spatial sprawl adapted to Kunshan's sustainable development.This paper firstly gives a discription of the definition,objectives and practical principles concerning "smart growth", and introduces some abroad practical cases under the guide of "smart growth". We analyzed spatial and temporal characteristics of Kunshan's spatial sprawl using 3S technology based on six periods of MSS, TM remote sensing images over 1970-2008 (1970,1984,1991,1998,2005,2008), data in statistical yearbooks and field survey data. Results show that Kunshan has undergone three periods of spatial sprawl:the stage of slow expansion(1970-1984), accelerating expansion (1981-1998) and rapid expansion(1998-2008); expansion intensities in each direction differ greatly, mainly in two-wing expansion. The primary expansion direction is southeast and secondary expansion direction is northeast.Through investigation in practical experiences in foreign countries combined with current situation of Kunshan city, We analyze Kunshan's urban expansion in three terms of open space at the edge of city, uaban growth boundary and compactness ratio related to urban spatial sprawl. Overall area of urban open space is stable while the area change in different direction is uneven. Analysis of landscape pattern indicates that the regularity degree of land patch in open space at the edge of city varys from regular to irregular and return to regular. The complexity and fragmentation of landscape shape increase with the decrease of the percentage of open space area. Setting urban growth boundary based on existing administrative boundary and extensible space together with expansion differences in each direction, We derive that the primary expansion direction is south and secondary expansion direction are southwest, west and north. In perspective of expansion intensities in each direction, Kunshan city's main spatial sprawl direction in the future should shift from east to south. Kunshan city's compactness ratio is low. The fact that the fractal dimension of urban land is declining implies that urban spatial expansion is primarily outward. urban morphology is complex and less stable. After carding the law of Kunshan city's urban expansion features and changes and considering its realistic conditions together with foreign experiences, the paper puts forward optimal strategies and suggestions for Kunshan city's urban sprawl as a reference to its future sustainable development.