Spatial and temporal dynamic analysis of wetland in Pearl River Estuary during 1988-2004

Rapid land use change has taken place in many coastal regions of China such as the Pearl River Estuary over the past tow decades due to accelerated industrialization and urbanization. In this paper, four temporal Landsat TM images were used at a spatial resolution of 30m to mapping wetlands and monitoring their changes in the Pearl River Estuary for the time period of 1988-2004. Hierarchical classification method based on spectral data, prior knowledge about the study area and GIS ancillary data were used to acquire four temporal wetland distribution maps, and three evaluation indicators (change ratio, change speed, and bidirectional dynamic degree model) were used to analysis the change characteristic of wetlands in the study area. The result indicated that there has been a rapid decrease of wetlands in the study area during 1988-2004. The total area of wetlands has lost about 122.66 km2 in the Pearl River Estuary.