Chao Phraya River
The headwaters of the Chao Phraya River originate in the northern part of Thailand and consist of four large tributaries, the Ping, Wang, Yom and Nan rivers. The Ping and Wang join just below the Bhumibol Dam to form the Ping River. The Yom and Nan join about 30 km (18 mi) north of Nakhon Sawan to form the Nan River. The Chao Phraya River begins at the confluence of the Ping and Nan rivers at Nakhon Sawan in central Thailand. It then flows from north to south for approximately 370 km (230 mi) from the central plains to Bangkok, eventually emptying into the Gulf of Thailand. In Chainat, the river splits into the main river and the Tha Chin River, which flows parallel to the main river until they both enter the Gulf about 35 km (22 mi) west of Bangkok in Samut Sakhon. The expanse of the Chao Phraya and Tha Chin rivers and their distributaries, starting at the point at which the distributaries diverge, together with the land between the triangle formed by the outermost and innermost distributaries, form the Chao Phraya Delta. The many distributaries of the Chao Phraya Delta are interconnected by canals that are used for both irrigation and transportation.