Impacts of a proposed water control project on the inundation regime in China's largest freshwater lake (Poyang Lake): Quantification and ecological implications

Poyang Lake, the largest freshwater lake in China, is connected to the Yangtze River and has been undergoing shrinkage over the past decade. The Poyang Lake water control project (PLWCP) was proposed to protect the lake against rapid shrinkage. However, the quantitative impact of the project on the floodplain inundation regime is not yet clear. This study used a hydrodynamic model to quantify the influence of the PLWCP on the inundation regime of upstream floodplains in Poyang Lake. Poyang Lake was characterised by high spatiotemporal heterogeneity in inundation patterns and that the northern lake areas were most affected, followed by the central and eastern lake areas. The western and southern lake areas were less affected. The water levels of the northern channels increased by a maximum of 4–5 m during the first recession period (16 Sep–31 Oct) and increased by 1–2 m during the impounding period (1 Sep–15 Sep). Most of the lake areas except the northern channels showed a water level increase of less than 0.5 m from November to March. The increased inundation areas were mostly 100–400 km2 (