Inland delta

An inland delta is a river delta that is inland rather than by the sea. The flowing water is divided there by obstacles and flow effects , for example before sediment deposits after flooding, with mostly a slight gradient into several watercourses. It usually flows into a terminal lake in a basin or seeps into a dry area. A branched section of a river in a lowland is also often referred to as an inland delta. Although all are based on the principle of the alluvial fan , the latter is known in technical terms as the anastomosing flow .

Inland delta without runoff

Satellite image of the Okavango Delta

In an inland delta with no outflow, a flowing body of water divides into two or more river arms, which then flow to the lowest point of a mostly outflow-free basin , where the water evaporates or seeps away. In such a landscape form, which can be lower than the surrounding area and also below sea level ( NN ), the water can also collect, so that especially in the tropical rainy season areas a wetland with periodic flooding is created. If the inflow of water is greater than the evaporation, swamps , cyclical or permanent lakes can arise in these basins .

Examples of an inland delta without a runoff are:

• Volga flows into the Caspian Sea
• Amu Darya flows into the Aral Sea ("End Sea ") (Uzbekistan)
• Syr Darja flows into the Aral Sea ("End Sea ") (Kazakhstan)
• Ili flows into Lake Balkhash ("Endsee") (Kazakhstan)
• Murgab seeps into the Karakum desert (Turkmenistan)
• Helmand flows into the Godzareh lowlands (Iran and Afghanistan)
• Tarim seeps into the Tarim Basin (China)
• Jordan flows into the Dead Sea
• Okavango flows into the Okavango Delta in the Kalahari (Botswana)
• Río Dulce flows into Mar Chiquita (Argentina)

Inland delta with drainage

An inland delta with a runoff is known as an anastomosing river. Here the water of one or more rivers in a lowland does not flow directly out of this landscape area. The (or the) flowing water first divides into two or more river arms, which often unite again at the lowest point of the area and continue to flow in a common river course. Through the bottleneck closing the area, the water in the inland delta can accumulate, creating a wetland with frequent flooding , or a lake.

Examples of an inland delta with a runoff are:

• Oderbruch north of Frankfurt (Oder)
• Hare at Quakenbrück
• Havel in the urban area of Brandenburg an der Havel , Rathenows and between Havel and Gülper Havel .
• Wümme at Fischerhude
• Elbe near Hamburg (part of the Lower Elbe, now forms the Port of Hamburg )
• Elbe near Lutherstadt Wittenberg
• Spree in the Spreewald
• Saale in the urban area of Halle (Saale)
• White Elster highly branched between Zwenkau and the mouth in the Saale is, when inflow of splices and Parthe Leipziger waters node called
• Alpine Rhine into Lake Constance
• Tiroler Achen flows in the course of its delta into the Chiemsee , which is drained by the Alz
• Danube valley between Bratislava and Iža
• Rhine-Meuse Delta in the Netherlands (the river marshes were narrowed by coastal bogs until the High Middle Ages)
• Leieebene in the North Department and the Province of West Flanders
• Tajo (Spain)
• Vardar Valley in Macedonia
• Whether in the West Siberian lowlands ; In addition, a delta and a supply hopper in the lower reaches of the river
• Rio Negro (Amazon) above Manaus
• Niger in the Massina lowlands; also an estuary delta at the end of the lower reaches
• Hadejia Nguru Wetlands in northeastern Nigeria
• Rio Purus flows into the Amazon along its delta
• Peace Athabasca Inland Delta (Canada)
• Mekong
• Ligawasan River Marshes and Agusan Marshes on Mindanao Island in the Philippines

See also

• muzzle
• Muzzle arm
• Dam bank river

Individual evidence

1. ↑ Geography Lexicon: Inland Delta On: geodz.com
2. ↑ Niels Thevs: Ecology, Spatial Distribution, and Utilization of the Tugai vegetation at the Middle Reaches of the Tarim River, Xinjiang, China . Cuvillier Verlag 2006, ISBN 3867274312 , p. 13 ( limited online version (Google Books) )
3. ^ Hermann Remmert : Special ecology: Terrestrial systems . Springer 1997, ISBN 3540582649 , pp. 216-217
4. ↑ Norbert Stein: Gülper Havel should flow again. In: maz-online.de . November 28, 2016, accessed August 26, 2020 . 
5. ^ Hansjörg Küster: The Elbe: Landscape and History . CHBeck 2007, ISBN 3406562094 , p. 137 ( limited online version (Google Books) )
6. ↑ UNESCO Spreewald Biosphere Reserve (inland delta) on the German UNESCO website
7. ^ Bertelsmann - the new universal dictionary . Wissen Media Verlag 2006, ISBN 3577102985 , p. 581 ( limited online version (Google Books) )