Abstract: Taking into consideration of the information of vegetation zoning, reflectance spectral signatures of land cover and field investigations, the estuarine and coastal wetland distribution information of Shanghai region is extracted from multiple Landsat-5 TM images on the basis of the determination of pixel threshold for land cover classification. With ArcGIS, spatial data of the wetlands both of tidal flat and terrain beneath water are integrated. Therefore the wetlands distribution in the past and present and changes are analyzed. Results show that the reclamation of the wetlands kept an increased trend for the past 15 years. Although the tidal flat still grows, the deposition speed obviously decreases and it does not catch up with the reclamation activities. Thus the size of wetlands of middle to high elevation has a decreasing tendency.

Key words: estuarine and coastal wetlands, remote sensing method, reclamation, GIS