PoyangLake-Hydrometeorological-Data

This study investigates the spatiotemporal dynamics and multi-scale driving mechanisms of water area changes in Poyang Lake, China's largest freshwater floodplain lake, over 2000–2022. By integrating multi-source remote sensing (MODIS, Landsat), hydrological data from six stations (water level, sediment discharge), and meteorological records from five stations (precipitation, temperature, potential evapotranspiration, relative humidity), we applied Empirical Mode Decomposition (EMD) and Mann-Kendall mutation tests to decompose time series into seasonal, interannual, decadal, and long-term decadal components. Results reveal a significant shrinking trend of 28.02 km²/yr, with a critical regime shift around 2011. Driving factors exhibit strong scale-dependence: precipitation dominates seasonally; potential evapotranspiration becomes primary at interannual scale (variance contribution rate 25.64%, R²=0.91); temperature correlates with long-term interannual changes; and relative humidity drives long-term decadal variations. Spatially, the representativeness of hydrological stations shifts with scale—Kangshan (seasonal/long-term interannual), Duchang (interannual), Tangyin (decadal), and Hukou (long-term decadal) emerge as key stations, reflecting differential influences of upstream processes versus Yangtze River interactions. Sediment discharge at Hukou declined dramatically (144.1% over 23 years), serving as a proxy for human activities (sand mining, reservoir operations) that alter river-lake water-sediment exchange and exacerbate lake shrinkage. This study provides a transferable multi-scale analytical framework for understanding floodplain lake responses to climatic and anthropogenic pressures.