Abstract:
Dongting Lake is the largest regulating lake in the middle and lower reaches of the Yangtze River. To study the trend in area changes of Dongting Lake accurately, the Landsat images from 1994 to 2017 were used to extract the water body area of Dongting Lake. Different water body extraction methods were compared. The water body was extracted based on water body index and visual interpretation, and the inter-annual and annual changes of Dongting Lake from 1994 to 2017 were analyzed. The results show that the normalized vegetation index (NDVI) combined with visual interpretation could accurately extract water body from complex features. The water body area of Dongting Lake changed significantly within the year. The maximum was in 1996(2438 km
2) and the minimum was in 2013 (1054 km
2), respectively. From 1994 to 2017, the area of Dongting Lake had a rising trend in 1990s and then decreased in 2000s and 2010s.