Chao Phraya River
The Chao Phraya begins at the confluence of the Ping and Nan rivers at Nakhon Sawan (also called Pak Nam Pho) in Nakhon Sawan province. It then flows south for 372 kilometres (231 mi) from the central plains to Bangkok and the Gulf of Thailand. In Chainat, the river splits into the main course and the Tha Chin river, which then flows parallel to the main river and exits in the Gulf of Thailand about 35 kilometres (22 mi) west of Bangkok in Samut Sakhon. In the low alluvial plain which begins below the Chainat dam, many small canals (khlong) split off from the main river. The khlongs are used for the irrigation of the region’s rice paddies.
For more information of this river, can be read in here.