River · Thailand
Chi
Chi is the longest river that stays entirely inside Thailand. For 765 kilometres it winds across the dry north-east before joining the Mun River, which carries its water on to the mighty Mekong.
Picture credit: Woodstone (Public domain) · Wikimedia Commons
Where is the Chi?
The river starts here: Phetchabun Mountains, northern Khorat Plateau, Thailand.
It ends in the the Mun River, and onwards to the Mekong.
Countries on the river: Thailand.
The story behind it
The Chi rises in forested mountains and then loops lazily across the Khorat Plateau, a wide table of land where rain falls only in one season. Its bends are so wide that from the air the river looks like a piece of loose string. Farmers pump water from it onto rice fields, and after harvest the dry paddies turn pale yellow. Around Roi Et and other towns people fish with round nets and raise silkworms in the villages nearby. In the monsoon months the Chi can burst over its banks and turn whole fields into a shallow lake; in the hottest weeks parts of the bed almost run dry and sandbars show. Scientists have dug up very old pots and bronze tools along the river, proof that people settled here thousands of years ago.
Questions children ask
How long is the Chi?
The Chi measures 765 kilometres. That makes it the longest river lying completely within Thailand, even though larger rivers touch the country's borders.
Which country does the Chi flow through?
The Chi flows only through Thailand, across the north-eastern region called Isan. It never crosses a border, which is unusual for a river of this size.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
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