Desert soils of the Al Qua'a region, United Arab Emirates (north-facing)
This photo is 180 degrees from "Desert soils of the Al Qua'a region, United Arab Emirates (south-facing)".
www.flickr.com/photos/jakelley/51891219569/in/dateposted-...
As I was concentrating on photographing the opposing landscape, I could feel the wind starting to pick up. I turned around and could not believe the sight. This was my first experience with a "HABOOB"; a type of intense dust storm carried on an atmospheric gravity current or weather front. Haboobs occur regularly in arid regions throughout the world. The tallest dunes on the horizon are over 100 feet. The estimated height of the dust cloud of fine sand is over 500 feet.
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Foreground:
Gypsic Aquisalids from the interior of the UAE. Gypsic Aquisalids are the Aquisalids that have a gypsic or petrogypsic horizon with an upper boundary within 100 cm of the soil surface. In the Unted States, these soils occur in Texas and Colorado.
Aquisalids are the salty soils in wet areas in the deserts where capillary rise and evaporation of water concentrate the salts near the surface. Some of these soils have redoximorphic depletions and concentrations. In other soils redoximorphic features may not be evident because of a high pH and the associated low redox potential, which inhibit iron and manganese reduction. These soils occur dominantly in depressional areas where ground water saturates the soils at least part of the year. The vegetation on these soils generally is sparse, consisting of salt-tolerant shrubs, grasses, and forbs. Although these soils may hold water at a tension less than 1500 kPa, the dissolved salt content makes the soils physiologically dry.
Salids are most common in depressions (playas) in the deserts or in closed basins in the wetter areas bordering the deserts. In North Africa and in the Near East, such depressions are referred to as Sebkhas or Chotts, depending on the presence or absence of surface water for prolonged periods. Under the arid environment and hot temperatures, accumulation of salts commonly occurs when there is a supply of salts and a net upward movement of water in the soils. In some areas a salic horizon has formed in salty parent materials without the presence of ground water. The most common form of salt is sodium chloride (halite), but sulfates (thenardite, mirabilite, and hexahydrite) and other salts may also occur.
The concept of Salids is one of accumulation of an excessive amount of salts that are more soluble than gypsum. This is implicit in the definition, which requires a minimum absolute EC of 30 dS/m in 1:1 extract (about 2 percent salt) and a product of EC and thickness of at least 900. As a rule, Salids are unsuitable for agricultural use, unless the salts are leached out. Leaching the salts is an expensive undertaking, particularly if there is no natural outlet for the drainage water. Two great groups are recognized—Aquisalids, which are saturated with water for 1 month or more during the year, and Haplosalids, which are drier.
Background:
A Typic Torripsamment. These areas are narrow sinuous dune ridges that form linear or roughly rectangular patterns around deflation plains and inland sabkha flats. The dunes have a relative relief of about 80m. Dune formations are variable due to multi-directional winds, and include barchanoid, transverse and star shapes. The star dunes are often higher than the surrounding dunes and form impressive and imposing features in the landscape. A white, gray or red surface veneer of fine to coarse sand and fine gravel occurs on the gentle slopes of the dunes adjacent to the sabkhas and deflation plains.
The land is used as low-density grazing. The map unit has sparse vegetation cover with Cyperus conglomeratus and Zygophyllum spp on the lower slopes of the dunes together with Calligonum comosum on the slopes and slip faces. The map unit forms part of the Cyperetum-Zygophylletum vegetation community.
The soils of this map unit are dominated by Typic Torripsamments, mixed, hyperthermic (85% AD158) in the high dunes. Other soils are Typic Petrogypsids, sandy, mixed, hyperthermic (5% AD123), Petrogypsic Haplosalids, sandy, mixed, hyperthermic (5% AD143) and Gypsic Haplosalids, sandy, mixed, hyperthermic (5% AD135) that are confined to the deflation flats.
For more information about describing soils, visit:
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052523...
For additional information about soil classification using Soil Taxonomy, visit:
sites.google.com/site/dinpuithai/Home
For more information about soil classification using the UAE Keys to Soil Taxonomy, visit:
agrifs.ir/sites/default/files/United%20Arab%20Emirates%20...
Desert soils of the Al Qua'a region, United Arab Emirates (north-facing)
This photo is 180 degrees from "Desert soils of the Al Qua'a region, United Arab Emirates (south-facing)".
www.flickr.com/photos/jakelley/51891219569/in/dateposted-...
As I was concentrating on photographing the opposing landscape, I could feel the wind starting to pick up. I turned around and could not believe the sight. This was my first experience with a "HABOOB"; a type of intense dust storm carried on an atmospheric gravity current or weather front. Haboobs occur regularly in arid regions throughout the world. The tallest dunes on the horizon are over 100 feet. The estimated height of the dust cloud of fine sand is over 500 feet.
__________________________________
Foreground:
Gypsic Aquisalids from the interior of the UAE. Gypsic Aquisalids are the Aquisalids that have a gypsic or petrogypsic horizon with an upper boundary within 100 cm of the soil surface. In the Unted States, these soils occur in Texas and Colorado.
Aquisalids are the salty soils in wet areas in the deserts where capillary rise and evaporation of water concentrate the salts near the surface. Some of these soils have redoximorphic depletions and concentrations. In other soils redoximorphic features may not be evident because of a high pH and the associated low redox potential, which inhibit iron and manganese reduction. These soils occur dominantly in depressional areas where ground water saturates the soils at least part of the year. The vegetation on these soils generally is sparse, consisting of salt-tolerant shrubs, grasses, and forbs. Although these soils may hold water at a tension less than 1500 kPa, the dissolved salt content makes the soils physiologically dry.
Salids are most common in depressions (playas) in the deserts or in closed basins in the wetter areas bordering the deserts. In North Africa and in the Near East, such depressions are referred to as Sebkhas or Chotts, depending on the presence or absence of surface water for prolonged periods. Under the arid environment and hot temperatures, accumulation of salts commonly occurs when there is a supply of salts and a net upward movement of water in the soils. In some areas a salic horizon has formed in salty parent materials without the presence of ground water. The most common form of salt is sodium chloride (halite), but sulfates (thenardite, mirabilite, and hexahydrite) and other salts may also occur.
The concept of Salids is one of accumulation of an excessive amount of salts that are more soluble than gypsum. This is implicit in the definition, which requires a minimum absolute EC of 30 dS/m in 1:1 extract (about 2 percent salt) and a product of EC and thickness of at least 900. As a rule, Salids are unsuitable for agricultural use, unless the salts are leached out. Leaching the salts is an expensive undertaking, particularly if there is no natural outlet for the drainage water. Two great groups are recognized—Aquisalids, which are saturated with water for 1 month or more during the year, and Haplosalids, which are drier.
Background:
A Typic Torripsamment. These areas are narrow sinuous dune ridges that form linear or roughly rectangular patterns around deflation plains and inland sabkha flats. The dunes have a relative relief of about 80m. Dune formations are variable due to multi-directional winds, and include barchanoid, transverse and star shapes. The star dunes are often higher than the surrounding dunes and form impressive and imposing features in the landscape. A white, gray or red surface veneer of fine to coarse sand and fine gravel occurs on the gentle slopes of the dunes adjacent to the sabkhas and deflation plains.
The land is used as low-density grazing. The map unit has sparse vegetation cover with Cyperus conglomeratus and Zygophyllum spp on the lower slopes of the dunes together with Calligonum comosum on the slopes and slip faces. The map unit forms part of the Cyperetum-Zygophylletum vegetation community.
The soils of this map unit are dominated by Typic Torripsamments, mixed, hyperthermic (85% AD158) in the high dunes. Other soils are Typic Petrogypsids, sandy, mixed, hyperthermic (5% AD123), Petrogypsic Haplosalids, sandy, mixed, hyperthermic (5% AD143) and Gypsic Haplosalids, sandy, mixed, hyperthermic (5% AD135) that are confined to the deflation flats.
For more information about describing soils, visit:
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052523...
For additional information about soil classification using Soil Taxonomy, visit:
sites.google.com/site/dinpuithai/Home
For more information about soil classification using the UAE Keys to Soil Taxonomy, visit:
agrifs.ir/sites/default/files/United%20Arab%20Emirates%20...