Abstract: Land use change, being one of the most important research area in global environmental change, has been used as one of the base data for decision-making in land use planning and policy at local governments in China. Numerous land use models are available developed from different disciplinary backgrounds, useful for disentangling the complex suite of socio-economic and biophysical driving forces that influence the rate and spatial pattern of land use change and for estimating the impacts of changes in land use. Land use systems are groups of interacting, interdependent parts linked together by exchanges of energy, matter, and information in social, economic, environmental and institutional dimensions. However, models that integrate techniques and methods developed in various disciplines would be too complex to be operational, especially for descriptive land use models that aim at simulating the functioning of the land use system and the spatially explicit simulation of near future land use patterns in heterogeneous regions. Consequently, simplified spatially explicit models at the macro-scale are also needed. Beijing, the capital of China, is under high pressure from land use change and inappropriate land management in suburb counties. Due to complex driving factors in different counties of Beijing suburb, it is difficult to formulate and quantify them in a model. Many of the existing methods in analyzing land use change have evaluated and explored the rate or spatial pattern or driving factors of land use change in a county or part of this region. A black-box method in this paper was developed to quantify the direction and magnitude of land use change in Beijing suburb from 1993 to 2004. The objective of the study is served for making more informed decisions in land use planning at the region level. Based upon land use inventory database of six representative counties, the weighted values of geometric centers of parcels were calculated with GIS and were used as the barycenters of the corresponding land use types. The coordinates of barycenters of the main land use types in 1993 and 2004 were compared and the results show that barycenters of arable land for the six counties were averagely shifted by 2,661m, orchard land by 1,826 m, forest land by 2,231 m, and built-up area (towns, villages and isolated industrial areas included) by 1,141m. The shifting directions of both arable land and built-up area in the two plain counties near Beijing town were similar, backward to town center of Beijing, which reflects land occupation during the urbanization of Beijing. However, the center of built-up area in another plain county far away from Beijing town was moved toward to town center of Beijing. These results indicate that development of built-up area has occupied a large amount of arable land in both near and far suburb of Beijing. The centers of forest land in the three mountainous counties far away from Beijing town had adverse shift directions to orchard land with largely decreased arable land. It is indicated that poor arable land in these counties was reformed to forest and orchard land. One of the reasons induced these shifts might be the government new policies on agriculture-structure-adjustment and reforestation in mountainous counties. The land use changes in Beijing suburb also reflect the integrated effects of economy growth, population increase, urbanization, road building, topography and original land use pattern. It is very clearly proved that the land use changes in Beijing suburb are towards to certain directions.

Key words: Land use change, land use type, barycenter, distance, direction, Beijing suburb

Biography: Xiao-gang Cui, Ph.D. candidate, mainly engaged in land survey.