Research on land-use structure in the water-level-fluctuating zone of Three Gorges Reservoir area based on information entropy — A case study of Kaixian County in Chongqing City, China

According to the operation of Three Gorges Project, a water-level-fluctuating zone with 30m high will come into being in Three Gorges Reservoir Area, which will bring a succession of ecological and environmental problems. Therefore the research on the land-use structure of water-level-fluctuating zone is very important for environmental protection in Three Gorges Reservoir Area. Using the land use data and remote sensing image from 2003 to 2009 in Kaixian County which holds the biggest area of water-level-fluctuating zone, this paper adopts the information entropy model to analyze the dynamic changes of land-use system´s order degree during the process of forming the Reservoir, and simulates five kinds of land use pattern. The results showed as following: 1) with the upgrade of reservoir water level, the entropy of land use system is increasing. It demonstrates that the land use structure is in higher order relatively in 2003, and land use disorder increased highly in 2009. 2) The wetland protection pattern is the optimal pattern in four simulation patterns. At the same time, it confirmed the importance of wetland protection in urban edge. Although the current “dam” pattern is sub-optimal, its ecological and economic benefits are relatively reasonable. Therefore current “dam” pattern is acceptable.