The principal tributaries of the Chao Phraya River of Thailand are the Pa Sak River, the Sakae Krang River, the Nan River (along with its principal confluent the Yom River), the Ping River (with its principal confluent the Wang River), and the Tha Chin River.[1] Each of these tributaries (and the Chao Phraya itself) is further tributed by additional minor tributaries often referred to as khwae. All of the tributaries, including the lesser khwae, form an extensive tree-like pattern, with branches flowing through nearly every province in central and northern Thailand.[1] None of the tributaries of the Chao Phraya extend beyond the nation's borders.[2] The Nan and the Yom River flow nearly parallel from Phitsanulok to Chumsaeng in the north of Nakhon Sawan province. The Wang River enters the Ping River near Sam Ngao district in Tak province.
Map of the Chao Phraya River drainage basin
The following is a tree demonstrating the points at which the major tributaries of the Chao Phraya River branch off from the main river and from each other.[1]
Additional tributaries of the Nan include the Than, Khan, Khlung, Haeng River, Fia, Kaem, Kap, Kleung, Bang Kaeo, Grung Grak, Ban Mung, and Sai Yoi Rivers, although the Royal Irrigation Department report provides insufficient data to link them to tributary tree.
Sapuat River (Placement in tributary tree is approximate, geographical coordinates unavailable due to inaccurate station data from Royal Irrigation Department)
Khanat River (Placement in tributary tree is approximate, geographical coordinates unavailable due to poor satellite resolution)
San River (Placement in tributary tree is approximate, geographical coordinates presently undeterminable due to recently built dam)
Tip River (Placement in tributary tree is approximate, geographical coordinates presently undeterminable due to recently built dam)
Phaem River (Placement in tributary tree is approximate, geographical coordinates unavailable due to poor satellite resolution)
Mempin River (Placement in tributary tree is approximate, geographical coordinates unavailable due to poor satellite resolution)
Lai River (2) (Placement in tributary tree is approximate, geographical coordinates unavailable due to poor satellite resolution)