Surface Water Changes in Dongting Lake from 1975 to 2019 Based on Multisource Remote-Sensing Images

Dongting Lake plays an important role in water regulation and biodiversity protection, but it is vulnerable to climate change human activities. To quantify surface changes factors driving them, long-term variation was investigated using the multiple spectral indices method based on a decision tree classification for full time-series Landsat MODIS datasets. Factors influencing were explored by combining annual maximum permanent occurrent with meteorological hydrological data. The results showed that both decreased from 1975 2019 trends of rainfall runoff at three outlets also changed. increased during 1990s due high again after 2000. A significant stage sequence 1986 occurred 2003, which coincided beginning work construct Three Gorges Dam (TGD). about 360 km2 150 × 108 m3 impoundment TGD, likely main cause 2003. area changed pre-TGD period into seasonally occurring post-TGD periods 209 km2, while 31 km2. Meteorological elements activities have had comprehensive impact Lake. Rainfall temperature account one-third influence water, factor wet season, dry season. Runoff outlets, four rivers Chenglingji explain half water; mainly affected water. monthly fluctuates regularly has strong seasonal characteristic. Indeed, are significantly altered when drought or flooding occurs, causes diverse complex.