Deserts of Afghanistan and Iran

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Iran's topography with Dascht-e Lut and Dascht-e Kawir

The deserts of Afghanistan and Iran belong to the Iranian highlands . Due to the turning circle, they are under the influence of Passatz circulation and are thus tropic deserts . In addition to these consequences, the aridity (drought) is increased by the surrounding rain-shielding mountains.

Lut

Dascht-e Lut photographed from space

The Dasht-e Lut ( Dasht means "plain, plateau, desert"; lut "empty") is 166,000 square kilometers, the largest desert in Iran. To the southwest lies the Zagros Mountains, which contribute to the aridity. The second great Iranian desert, the Kawir, joins in the north. As a result of these conditions, the annual precipitation is less than 50 mm (with a potential evaporation of 5000 mm). The desert is one of the hottest places on earth. A soil measurement in summer by satellite showed 70.7 ° C. A scientific expedition was able to measure an even hotter temperature of 78.2 ° C.

While an erosion relief has formed in the south-west, in the south-east there is an embankment with dunes up to 420 m high . In contrast to the Sahara , for example , no finds have been made that testify to previous human settlement. So far, no fossils or other indications of previous life have been found. Due to these hostile conditions, the Lut is still deserted today.

Nomads live in the mountains south of the Lut in summer, in winter they move on towards the Persian Gulf .

Kawir

Maranjab dunes in the Kawir desert

Dascht-e Kawir (دشت كوير; also Kavir or Kewir ) is the Persian name of the "Great Salt Desert " in the Iranian highlands north of the Lut. It is about 78,000 km² and lies in a high basin between the Zagros Mountains in the southwest and the Elburs Mountains in the north. These mountains shield both the Kawir and the Lut from precipitation; but earlier the monsoon rains reached today's desert, which was formed about 3000 years ago from a series of glacial lakes. Because of the sterile and hostile conditions of the salt plains, the Kawir is also uninhabited. Minerals are broken down from the extensive salt deposits.

The Iranian Space Agency operates space launch sites in this desert, for example in Emamshahr in the Semnan province .

Qanats

Distribution grid of a qanat
The kayakai dam built in 1953 dams the
Hilmand Rud river , photo taken in 2004

On the southern edges of the Lut and Kawir there are numerous oases on which the qanats are based. Qanats are horizontal wells that draw groundwater from the mountains. They do not allow sustainable use, as they only use recent rainfall from the mountains. They were developed before the turn of the century and have been spread as far as China. As recently as the 1960s, there were an estimated 22,000 wells in the country.

Jaz Murian

The Jaz Murian Basin is located in southeastern Iran in the area of ​​the provinces of Kerman and Sistan and Balochistan . In the north it is delimited by the Jebal Barez-Shah and Savaran-Bazman chains from the Lut Basin, in the south by the foothills of the Zagros Mountains and the Makran , the area is around 68,311 km². In the center of the basin is a seasonal lake Hamun-e Jaz Murian with a size of around 13,000 km², which is mainly fed by the Halil and Bampur rivers. On average, it has an area between 200 and 400 km². During the last flood in January 2020, the greatest extent of the last decades was measured at 3000 km².

Afghanistan

The southern part of Afghanistan is almost entirely a desert area. In the mountains of central and northern Afghanistan, there is more rain than in the southern regions, but there are many very dry places - especially in the rain shadow of the mountains.

The Hilmend River divides the desert areas of southern Afghanistan into an eastern and a western half. East of the Hilmend is the Rigestan desert (also Registan , "sand land"). Rigestan is a sandy and sparsely vegetated desert of around 25,000 km², which is grazed by Baluch . West of the Helmund is also mainly of gravel and Lehmflächen from salt flats existing Dascht-e Margoh .

literature

Web links

Commons : Deserts in Asia  - Collection of images, videos and audio files

Individual evidence

  1. Eos, Vol. 87, p. 461, 2006
  2. GEO No. 11/2017 - Desert Lut. Retrieved December 22, 2017 (German).
  3. Satellite image of the week: Beauty full of salt and dust . In: Spiegel Online , January 21, 2012
  4. Iran's Long-Range Missile Program: New Launch Facility Revealed. US Naval Institute, March 2010, accessed April 10, 2010 .