Reservoir silting can be divided according to sediment dynamics into two basic types-reservoir (hydrodynamic) silting and river hydrodynamic silting, for which two types of sediment models can be constructed. The area of silting in reservoirs was estimated by measuring the area exposed during low water level periods. Statistical data was collected from 30 reservoirs through the combination of Landsat images. Silting degrees were divided into three grades: gradeⅠ, silting degree DEPDEV＜-0.3; gradeⅡ, silting degree DEPDEV=-0.3～1; grade Ⅲ, silting degree DEPDEV＞1. The results establish the characteristics of silting degrees in the larger drainage area.