Moated castle (hydrology)
In hydrology , a water castle (sometimes also water tower ) is colloquially an area, usually mountains, that continuously releases water to other, drier areas. The term has no scientific character, but serves to illustrate the storage and supply capacity of an area. Similarly, water tower is used in English and Château d'eau (water tower or castle) in French .
Physical background
When air rises on mountain slopes, it cools down due to the lower air pressure ( dry adiabatic 1 ° C / 100 m, wet adiabatic 0.5 ° C / 100 m). If the dew point is reached (moisture adiabatic), gradient precipitation occurs. Therefore, it usually rains more in mountain regions than in the surrounding plains and many rivers have their source in mountain ranges. If, due to the altitude, frozen water collects in the form of glaciers or snow, this creates a buffer that releases the water to the surrounding area with a delay.
Examples
Europe
The most common is the use of the term in relation to the Alps, or Switzerland as the “water castle of Europe”, due to the topography of the Alps and the clashing influences of the Atlantic maritime climate, the continental climate and the Mediterranean climate. The Rhine , the Rhone and important tributaries of the Po have their source in the Gotthard massif . The Aletsch Glacier , the largest and longest glacier in the Alps, is also nearby .
In particular, the area in the triangle of Brugg , Windisch , Gibstorf , Turgi , Stilli and Untersiggenthal on the southern edge of the Jura is known as Switzerland's moated castle , where the three rivers Aare , Reuss and Limmat, coming from the Alps , unite in the Vogelsang district of Gibstorf. The term "moated castle" was established here to protect the area in the 1970s.
Asia
The Himalayas are known as the "water castle of Asia". Here are the main sources of the Indus , Satlej (Satluj), Brahmaputra , Ganges , Yamuna and Ghaghara rivers . Furthermore, the rivers Irrawaddy , Saluen , Mekong , Jangtsekiang , Yarkant and, in a broader sense, the Huang He draw a relevant part of their water from the Himalayas. They supply water to over 1.3 billion people.
Africa
Ethiopia is the moated castle of eight major rivers. The source rivers of the Blue Nile, for example, have their source in the Abyssinian highlands . From there, over 86% of the water of the Nile comes from at the mouth.
A total of eleven areas in Africa are designated as water towers by the United Nations Environment Program :
| area | country |
|---|---|
| Middle Atlas | Morocco |
| Fouta Djallon | Guinea |
| Jos plateau | Nigeria |
| Abyssinian highlands | Ethiopia |
| Kenyan highlands ( Mount Kenya massif ) | Kenya |
| Albertine Rift ( Ruwenzori Mountains ) | Uganda / Democratic Republic of the Congo |
| Bié highlands | Angola |
| Lufilian arch | Democratic Republic of the Congo / Zambia |
| Southern highlands | Tanzania |
| Lesotho highlands ( Drakensberg ) | South Africa / Lesotho |
| Central high plateau | Madagascar |
Individual evidence
- ↑ a b Moated castle in a thirsty world: Importance of the mountains for the water balance
- ^ A b Climate Change Will Affect the Asian Water Towers
- ↑ Le rôle des Alpes comme "château d'eau de l'Europe" draws en question - Le Point
- ↑ Introduction to Meteorology Part I. of the University of Munich
- ^ Experts seek to preserve Europe's water tower
- ↑ Hydrological Atlas: The water memory of Switzerland. In: Hydrological Atlas of Switzerland . Federal Office for the Environment, 2018, accessed on January 3, 2019 ( ISBN 978-3-9520262-0-5 ).
- ↑ Federal inventory of landscapes and natural monuments of national importance BLN - BLN 1019 Wasserschloss at the confluence of the Aare, Reuss and Limmat rivers.
- ↑ Fabian Ruether, Goethe Institute
- ↑ Christina Heidl, Goethe Institute
- ↑ [1] lnformationsnotiz EMBASSY Department of Foreign Affairs FDFA - Strategy for the Horn of Africa from 2013 to 2016
- ↑ With open cards Egypt without the Nile? Jan 15, 2011
- ^ UNEP - Africa Water Atlas; page 6