Why is Lake Poyang important to the Yangtze River basin?

Lake Poyang is vital to the Yangtze River basin primarily due to its role in hydrology and flood regulation. As China’s largest natural freshwater lake, it serves as an important retention basin that receives excess water from the Yangtze during flood periods, helping to mitigate the impact of high water levels on the surrounding plains.123

Additionally, the lake is a significant contributor to the river's overall water volume. Runoff from the basins of Lake Poyang and Dongting Lake together accounts for approximately two-fifths of the total water volume delivered to the mouth of the Yangtze. While the lake is essential for managing seasonal fluctuations, it is subject to significant changes in size and depth, and it has faced challenges in recent centuries due to silting and land reclamation, which can affect its capacity to regulate the river's flow.413