Inland (endorheic) drainage is a system in which rivers do not reach the sea but end in an inland lake, a salt flat, or simply disappear into the desert sand, in contrast to exorheic drainage that flows to the ocean.
- A basin with no outlet to the sea is called an endorheic or closed basin; water leaves it only by evaporation or seepage, so salts accumulate and the terminal lakes are often saline.
- In India, inland drainage is mostly seasonal and found in the arid Rajasthan-Thar region; the Luni is the only notable river there, rising near Ajmer and ending in the marshy Rann of Kachchh rather than the sea.
- Many small Rajasthan streams drain into salt lakes such as Sambhar, or vanish in the desert during the dry season; the Ghaggar is a stream that loses itself in the sands.
- Worldwide examples of inland drainage include the basins of the Caspian Sea, the Aral Sea, the Dead Sea (Jordan), Lake Chad, and Lake Eyre in Australia.
- Inland-drainage regions, being arid and evaporative, develop salt lakes and saline soils, important for soil and water management.
The terms endorheic and inland drainage, the Luni as India's main inland river ending in the Rann, the salt-lake link (Sambhar), and world examples (Caspian, Aral, Dead Sea) are recurring drainage facts.
Inland or endorheic (no outlet to sea, ends inland) versus exorheic (reaches the ocean); the Luni ends in the Rann of Kachchh, not the Arabian Sea; inland drainage in India is mainly seasonal and confined to the arid west.
Drainage that ends inland, not in the sea (endorheic); in India it is mainly the seasonal Rajasthan streams and the Luni ending in the Rann of Kachchh.