| Chi River | |
|---|---|
.jpg) Chi River in December 2020 bordering between Yasothon and Roi Et provinces | |
 Map of the Mun River watershed showing the Chi River | |
| Native name | Mae Si (Thai) |
| Physical characteristics | |
| Source | |
| • location | Chaiyaphum |
| Mouth | |
• location | Mun river, Sisaket Province |
• elevation | 110 m (360 ft) |
| Length | 765 km (475 mi) |
| Basin size | 49,480 km2 (19,100 sq mi) |
| Discharge | |
| • location | Yasothon |
| • average | 290 m3/s (10,000 cu ft/s) |
| • maximum | 3,960 m3/s (140,000 cu ft/s) |
The Chi River (Thai: แม่น้ำชี, RTGS: Maenam Chi, pronounced [mɛ̂ː.náːm tɕʰīː]; Northeastern Thai: แม่น้ำซี, pronounced [mɛ̄ː.nâːm si᷇ː]) is the longest river flowing wholly within Thailand. It is 765 kilometres (475 mi) long but carries less water than the second longest river, the Mun. The name of the river is "Mae Si" ([sīː]) in the Isan and Lao languages of the region, being transliterated as "Chi" in Bangkok-Thai. In wet seasons there are often flash floods in the floodplain of the Chi River basin.[1]