Endorheic basin

Endorheisch (Greek ἔνδον endon, inside '; ῥεῖν rhein, to flow ') is called in the geosciences river basins with no outlet. The antonym is exorheisch ( drainage into the sea ).

Endorheisches basin called the regions of the earth that do not drain into the oceans, but form separate water systems. The Endgewässer called endorheisches waters.

The Caspian Sea, for example, is the last collection basin for a large, been filled.The of the Volga as a drainage basin. It forms along with several other basins a coherent endorheisches area, which extends from central Russia to central China and almost to the Indian Ocean, and occupies about 7 % of the solid surface.

The term implies outflow hydrology that it is superficial drain - groundwater exchange between a endorheischen area and neighboring areas is possible. Not covered by the term, but endorheisch ' fall sequels as an underground watercourse ( outflow -free pond, sinkhole or entanglement ). Main characteristic is that the water just evaporates primarily - is formed in lakes under circumstances of high salinity ( Dead Sea, Great Salt Lake, but not necessarily: Lake Neusiedl ). In the Aral Sea or Lake Chad during the evaporation is so strong that they begin to disappear entirely. An example of an intermittent lake is the Etosha Pan, a the two aforementioned comparable former salt lake, now a salt desert, which is the shallow lake for exceptional events.

As endorheischer flow is accordingly a flow denotes the non- drained into the sea, but a endorheisches Still waters ( examples: Volga to the Caspian Sea, Jordan to the Dead Sea ), or in an outflow basin without flows (examples: inland delta of the Okavango, Onyx of a McMurdo Dry Valleys ). The term is distinguished from the river sinkhole where a river run its course lose all without end in a sink - such a flow can also just about disappear, because in arid climate evaporates more water than flow well, or stops flowing (Example: wadis of the Sahara ), or permeable soil percolates ( infiltration route, such as the alluvial Südalpenflüsse in the Po Valley ) or swallowed ( sink-holes of the Karst waters).

Flat basin endorheischer drainage systems ( pans) can overflow during heavy water, it then arise episodic outflows (example: Okavango Basin, dehydrated under circumstances to the 300 km distant Makgadikgadi pan).

Other typical endorheic crater lakes and waters are cirque lakes nichtarider zones that also during heavy rain or during the spring thaw can run intermittently.