Gan River, river, chiefly in Jiangxi sheng (province), China. The Gan River is one of the principal southern tributaries of the Yangtze River (Chang Jiang). Its headwaters rise in Guangdong province, where the Dayu Mountains divide southwestern Jiangxi from Guangdong. This upper stream is called the Zhang River. Another stream, the Gong River, rises in the Jiulian Mountains in the far south of Jiangxi. These two streams flow together near the city of Ganzhou, and from there the Gan flows north through Jiangxi province into Lake Poyang and thence into the Yangtze. The river’s valley provided an important route in historical times from Guangzhou (Canton) in Guangdong to the Yangtze valley and the north. The total length of the Gan is 506 miles (815 km).
The Gan below Ji’an, in Jiangxi, is navigable by small steamers during the summer high-water period, but in winter these craft can only reach Zhangshu. Above Ji’an the river is obstructed by rapids, and the 95 miles (150 km) from Ji’an to Ganzhou takes some nine days by junk. The Zhang River is navigable by small craft to Dayu, as is the Gong River to Huichang, from where easy passes lead into Guangdong. That route was used between Guangzhou and the Yangtze valley until 1840, during the time that all foreign trade was concentrated in Guangzhou; imports to central China and tea exports from this region were shipped via this route. With the construction in 1937 of the main rail link between Guangzhou and Hankou in Hubei province via the alternative western route through Hunan province, the importance of the Gan River, except for local transport, declined. In addition to the streams that form its headwaters, the Gan has one major tributary, the Jin River, which flows eastward from the border of Hunan, joining the main stream some distance above Nanchang. The Jin valley provides the major east-west route across the north of Jiangxi.