Analysis of Spatial and Temporal Variation in Water Coverage in the Sub-Lakes of Poyang Lake Based on Multi-Source Remote Sensing

As the largest freshwater lake in China, Poyang Lake is an internationally important wetland and migratory bird habitat Asia. Many sub-lakes distributed basin are seasonal lakes, which have a significant impact on hydro-ecological processes susceptible to various changes. In this study, using multi-source remote sensing data, continuous time-series construction method of water coverage suitable was developed. That combined downscaling MNDWI (modified normalized difference index) with ISODATA (iterative self-organizing data analysis technique algorithm), its accuracy can be up 97% months when Landsat 8 available or 87% it unavailable. Based that method, increasing variation observed during 2013–2020 within range 200–690 km2 normally. The center always remained inundated (>80% inundation frequency), while surrounding areas were probably kept dry for seven (except June September). dominant influencing factors variations different hydrological periods (wet season dry–wet season: discharge; temperature wind speed; wet–dry precipitation). addition, “returning farmland lakes” affected increase area sub-lakes. This study helpful management resources protection birds region.