A study on the information entropy and fractal dimension of land use structure and form in Shanghai

Abstract

Land use change is an important component of global environmental change, and a representation of the impact of human activities on physical environment. Study on regional and urban land use change is the newest trend now. This paper studied land use structure and form changes of the central area in Shanghai from 1947 to 1996 and revealed all the driving factors leading to such changes based on the system ideas and the fractal theories. The paper calculated and compared the information entropy and equilibrium degree of land use structure on different condition. The results showed that the information entropy and equilibrium degree of land use structure were increasing gradually based on study area, but were decreasing from 1947 to 1958 and start to increase since 1958 based on urbanized area. The differences in areas of each land use type are reducing and the land use structures are approaching to equilibrium state in Shanghai. In recent 50 years, the boundary dimensions of urban industrial area, farmland, village small town construction area and reserved land for construction purpose have an ascending trend, their boundary forms are even more complicated, but residential area and other urban landscapes change little. The radius dimensions of residential area, industrial area, other urban landscape and village small town construction area were increasing gradually, those of agricultural area and reserved land for construction purpose had an ascending trend before 1979 and started to descend since 1979. In recent 50 years, all the land use types have been expanding from city center to peripheries with different speeds and degrees.The radius dimension of farmland is maximal and that of residential area is minimal, which forms an annular spatial pattern from residential area to industrial area and to agricultural area according to distance away from city center. All these spatial-temporal feature changes are impacted by the local environment, traffic condition, economic development and government conduct, while economic development and government conduct are the most important driving factors leading to urban form changes.