Some rivers never find the sea
In an endorheic basin, rivers end in a lake or a salt flat. The Okavango dies in a delta in the Kalahari and does not reach an ocean.
Established2 min read
About a fifth of the land surface drains inward. The Caspian, the Aral, the Great Salt Lake, and Lake Chad sit in such bowls. Water leaves by evaporation, and the salts stay, which is why the lakes are often saline and why they shrink when the climate dries.
The Okavango is the clear case: a river that would be famous if it reached a coast, spreading instead into a fan of channels in Botswana and soaking into the sand. In flood years the fan is a wetland the size of a small country. In dry years it retreats.
Caveats
- 'Never' means the surface channel. Groundwater, and a wetter century, can change where a basin spills.
- Some endorheic lakes were connected to the ocean in wetter times. The basin is a present fact, not an eternal one.
Sources
- 1McCarthy T. S., Ellery W. N.. The Okavango Delta. Transactions of the Royal Society of South Africa 53, 1998.