How does Hunan’s terrain slope toward Dongting Lake?

The terrain of Hunan province is characterized by highlands in the west, south, and east that fall steadily in elevation toward the plain of Dongting Lake in the north.1

This northward slope dictates the province's drainage pattern, as nearly the entire river system of Hunan flows toward this central basin. Specifically:23

• Western Highlands: Drained by the Yuan River and the Zi and Li streams, which flow from the mountainous regions toward the lake.23
• Southern and Eastern Borders: The Xiang River rises in the southern Nan Mountains and flows northward, joined by numerous smaller rivers originating in the eastern mountain ranges.12

As these rivers descend from the higher elevations, they carry significant amounts of silt, which has formed the fertile floodplain surrounding the lake. Ultimately, the waters of this entire system discharge into the Yangtze River at Yueyang.13