Abstract: The DEM model of Zhangdu Lake region is set up by means of topographic map scan supported by geographical information system. Using RS and GIS technology, DEM model was overlaid with the LANDSAT-7 TM image, average elevation of different wetland was drawn out. By carrying on statistical analysis to the data, the relation models of the water level and area, the water level and volume, and area and volume is computed. Combining with the agriculture condition and the ability of draining flood of water conservancy projects, the authors simulate in quantity the difference of storage capacity in Zhangdu Lake region before and after connecting to Yangtze River. In Zhangdu Lake region, the largest storage capacity is 1.644×10⁸m³ and the water area is 38.75 km² before connecting to Yangtze River, however, after connecting to Yangtze River, the largest storage capacity is 9×10⁸m³ and the water area is 2.73 ×10⁸m².

Key words: Zhangdu Lake region, digital elevation models, storage capacity, simulation analysis