Multi-scale characterization of land use pattern and its changes in China.

This paper analyzes the pattern of land use in China by GIS to reveal the factors that determine the distribution of the different land use types. Firstly correlation and regression analyses were used to identify the major explanatory variables from a large set of candidate determining factors. We found that the distribution of all the land use types in China was best described by a combination of different biophysical and socio-economic factors. The distribution of different crop types was closely related to climatic differences over the country. Emphasis was placed on the influence of the scale of analysis on the results of the study. On the basis of all these correlation and regression analyses, a multi-scale spatial analysis by GIS modeling on the distribution of different land use types has been carried out Both resolution of the data and the extent of the study area influenced the revealed relations. The systematic and quantitative characterization of the land use distribution presented in this paper can be used in spatially explicit land use models. Introduction The natural land cover is heterogeneous at all levels of observation, due to the heterogeneity of the environmental conditions, such as temperature and moisture conditions (Woodward, 1987). The actual distribution, however, only occasionally results from physical limitations. More usually the ecologically allowable is a subset inside what is physically possible. This is mainly due to competition between individual plants or between ecosystems as a whole (Meisel and Turner, 1998). Human use of land has altered the structure and functioning of ecosystems (Vitousek et al., 1997). Human activities override natural changes of ecosystems. Agriculture, forestry, and other land-management practices have modified entire landscapes and altered plant and animal communities of many ecosystems throughout the world (Ojima et al., 1994). The most spatially and economically important human uses of land globally include cultivation in various forms, livestock grazing, settlement and construction, reserves and protected lands, and timber extraction (Turner II et al., 1994). A better understanding of the determining factors of land use change is of crucial importance to the study of global environmental change (Turner II et al. 1994). The study of land use in China is relevant as China has a long history of land use under ever increasing population pressure in a very diverse natural environment. In recent years, the high population pressure, in combination with economic development, has resulted in the conversion of arable land area into non-agricultural uses. Together with the loss of arable land through degradation this situation is undermining China's food production capacity (Huang and Rozelle, 1995). The different processes determining the land use pattern have each their own optimal scale level at which the process can be studied (Fresco, 1995). For the system as a whole, there is not an optimal scale level (Levin, 1993). Therefore, a multi-scale approach, including the study of the system at different levels of integration, Institute of Natural Resources and Regional Planning, CAAS, Baishiqiao Road 30, Haidian, Beijing 100081, P.RChina; * Wageningen Agricultural University, The Netherlands