Thanlwin (thänlwēnˈ) [key] or Salween sălˌwēnˈ, Chin. Nu Jiang, Tibetan Chiama Ngu Chu, river of SE Asia, c.1,750 mi (2,820 km) long, rising in E Tibet region of China, and flowing SE through Yunnan prov. in deep, narrow gorges parallel to the Mekong, Chang, and Ayeyarwady rivers, into Myanmar, where it cuts through the Shan Plateau and Karenni Hills and then empties into the Gulf of Martaban, E Myanmar, near Mawlamyine. Because of rapids, it is navigable only for about 75 mi (120 km) upstream. Flowing through gorges for nearly its entire length, the Thanlwin is an obstacle to east-west transportation; it is crossed by the Burma Road and several road ferries. The river's depth varies c.65 ft (20 m) between wet and dry seasons, making it useless except for floating logs downstream.