2.2 Data collection
The data used in this study include the following contents. (1) The weather in flood and dry seasons in the Poyang Lake basin is primarily cloudless. This study chose this period’s images to analyze to avoid cloud cover interference on sensing images. The remote sensing images of Poyang Lake Basin are from the Landsat series (MSS, TM, ETM+, OLI). Data distribution is from 1977 to 2021(Fig.2), downloaded from the United States Geological Survey (USGS, website athttps://earthexplorer.usgs.gov//). Selected high-quality images with a suitable extraction effect, and the extraction results passed visual inspection. Finally, 328 images were screened by excluding missing data from 1980, 1982, 1985, 1994, and 2009. (2) To better reflect the lake changes, we compared historical images of Poyang Lake with earlier periods of less anthropogenic disturbance. The historical images were high-resolution satellite images on December 13, 1967, taken by the USGS (website athttps://earthexplorer.usgs.gov//). Visual inspection showed that the extraction results were accurate. (3) Runoff and sediment data were obtained from the actual measurements of hydrological stations in the Poyang Lake basin and lake estuary (Fig.1), recorded in the Hydrology Data Yearbook published by the Ministry of Water Resources and Power, PRC. Runoff data distribution period 1977 to 2020, sediment data distribution period 1980 to 2020. (4) Temperature and precipitation data of the Poyang Lake Basin were obtained from 23 measurements of meteorological stations (Fig.1), downloaded data from the China Meteorological Data Network (http://data.cma.cn/). Data distribution period 1977 to 2020. (5) The land use data of Poyang Lake Basin were obtained from China National Land Use Database and have been classified by a secondary classification system. Selected 1980, 1995, 2000, 2005, 2010, 2015, and 2020 land use data. All measured data used in this study were checked and rated as good quality.