Copyright The Columbia University PressThe Columbia Encyclopedia, 6th ed. The Columbia University Press
Chao Phraya (chou präyä´), Mae Nam Chao Phraya, or Menam Chao Phraya (both: mănäm´), chief river of Thailand, c.140 mi (230 km) long, formed by the confluence of the Ping (c.300 mi/480 km long) and the Nan (c.500 mi/800 km) rivers at Nakhon Sawan, W central Thailand. It flows S past Bangkok to the Gulf of Thailand and is navigable for its entire length. With its tributaries, the Chao Phraya drains most of W Thailand; its valley is the country's main rice-producing region. The many distributaries of the Chao Phraya delta are interconnected by canals that serve both for irrigation and for transportation.