Application of Sleuth Model for Planning Scenarios Comparison: A Case Study of Chongqing, China

This research simulated the urban growth scenarios of a mountain city of Chongqing, China through a CA-based model of SLEUTH. The fundamental data were four Landsat TM images of 1978, 1988, 1993, and 2001 which were utilized for generating maps of land use, road networks, and urbanized area. Three alternative development scenarios, including business as usual, compact city and decentralized concentration, were interpreted into the model. Business as usual assumes historical development would carry on. Compact city aims to achieve a compact and continuous urban form. Decentralized concentration promotes polycentric urban structure. The result presents several interesting findings with important planning implications. First, it was noted that predominant urbanization modes in mountain regions were "spread", indicating that new developments usually occurred at the edge of existing urban areas. Second, "breed" indicating that emerging small and sporadic urban patches can easily become new growing poles and induce new developments, was another major growth mode. Moreover, setting limitation to development on steep slopes has largely restricted urban expansion and effectively protected forests. However, it also suggested that there exists no optimal scenario as urban development and nature conservation are conflicting goals in terms of the selected landscape metric.