An Approach to Estimate the Water Level and Volume of Dongting Lake Using Terra/MODIS Data
应用Terra/MODIS卫星数据估算洞庭湖蓄水量的变化

By using Terra/MODIS satellite data in 2002, the dynamic variation of surface water area and water storage in Dongting Lake was studied. We, at first, divided the whole Dongting Lake into three parts (WDL: West Dongting Lake, SDL: South Dongting Lake, EDL: East Dongting Lake from west side) according to geographical characteristics. Secondly, surface water area was detected based on the spectral deference between water and terrestrial area using satellite (Terra/MODIS) NDVI (Normalized Difference Vegetation Index) data. Thirdly, the surface water area was overlaid on the lake bottom DEM with a grid size of 50 m by 50 m, and the water level could be calculated. Finally, the water storage was obtained by times water depth (difference between water surface elevation and lake-bottom elevation.) with the grid area. The total water storage at Dongting Lake was calculated by accumulating all water column values in the whole lake. By comparing the estimated water level and storage with the measurements in the three parts of the Dongting Lake, we found that there are high correspondences between the two, which implies that our method is an effective approach to estimate water level and water storage of a large lake.