Hsi Chiang

a river in South China.

The Hsi Chiang is 2,130 km long and drains an area of 437,000 sq km, including approximately 11,000 sq km in Vietnam.

Originating on the Yünnan Highlands, the river becomes the Hsi Chiang above the city of Nanning, at the confluence of two sources: the northern (main) source, the Yu Chiang (Hsiang Chiang), and the southern source, the Tso Chiang, whose headwaters are in Vietnam. The Hsi Chiang flows for some distance through a deep, precipitous valley and cuts through highly karstified regions. At certain points, rapids make passage difficult. The middle course of the Hsi Chiang is 340 m wide at Lungtang Gorge, its narrowest point; in other areas, it broadens to 2,660 m. The Hsi Chiang forms the broad Chu Chiang delta (area, 16,900 sq km), where the Hsi Chiang, the Pei Chiang, and the Tung Chiang converge. It empties into the South China Sea near Macao.

The mean flow rate near the city of Wuchou is about 8,000 cu m per sec, with a maximum flow of 58,000 cu m per sec during the summer monsoon floods. The mean annual outflow from the rivers of the Hsi Chiang basin is 363 cu km. The water level fluctuates annually by as much as 15–20 m. Floods occur often, more than 100 times since the early 17th century. They are especially dangerous in the delta when they coincide with high sea tides. More than 2,000 km of dikes have been built along the river to protect fields and settlements.

The Hsi Chiang provides irrigation water. Pearls are found in the lower Hsi Chiang. The river is navigable as far as Wuchou. The seaport of Canton (Kuangchou) is located in the delta of the Hsi Chiang.