BS Kinetics - underwater housings for photo- and videocamera › BS Kinetics 15.09.2016 bis 18.09.2016 BS Kinetics© – Quality built on passion The BS Kinetics© GmbH in Achern (Baden) is specialized in constructing modern carbon underwater housings for all types of photo and video cameras including special constructions for the whole world of diving since 1998. The whole development and production process, from the construction through to the maturity phase of the underwater housings – “MADE IN GERMANY”- takes place inhouse in Achern. Also the quality check, the individual pressure and breaking test are performed inhouse before delivering the photo and video housings to the customer. All our underwater housings have been given the names of different deserts according to our high quality standards. This reflects our commitment to create a dry place for your photo and video cameras. All BS KINETICS © housings and a large amount of accessory are available at our premium-reseller : Types of Deserts Deserts are classified by their geographical location and dominant weather pattern as trade wind, midlatitude, rain shadow, coastal, monsoon, or polar deserts.

Former desert areas presently in nonarid environments are paleodeserts, and extraterrestrial deserts exist on other planets. Trade wind deserts The trade winds in two belts on the equatorial sides of the Horse Latitudes heat up as they move toward the Equator. These dry winds dissipate cloud cover, allowing more sunlight to heat the land. Most of the major deserts of the world lie in areas crossed by the trade winds. The world's largest desert, the Sahara of North Africa, which has experienced temperatures as high as 57° C, is a trade wind desert. The Sahara of Africa is the world's largest desert. It contains complex linear dunes that are separated by almost 6 kilometers. (Skylab photograph). Midlatitude deserts Midlatitude deserts occur between 30° and 50° N. and S., poleward of the subtropical highpressure zones. These deserts are in interior drainage basins far from oceans and have a wide range of annual temperatures. The Sonoran Desert of southwestern North America is a typical midlatitude desert. A rare rain in the Tengger, a midlatitude desert of China, exposes ripples and a small blowout on the left.

Winds will shortly cover or remove these features. Rain shadow deserts Rain shadow deserts are formed because tall mountain ranges prevent moisture-rich clouds from reaching areas on the lee, or protected side, of the range. As air rises over the mountain, water is precipitated and the air loses its moisture content. A desert is formed in the leeside "shadow" of the range. This Landsat image shows the Turpan Depression in the rain shadow desert of the Tian Shan of China. A sand sea is in the lower center on the right, but desert pavement, gray in color, dominates this desert. The few oases in the desert and the vegetation in the mountains at the top are in red. A blanket of snow separates the vegetation in the Tian Shan from the rain shadow desert. Coastal deserts Coastal deserts generally are found on the western edges of continents near the Tropics of Cancer and Capricorn. They are affected by cold ocean currents that parallel the coast. Because local wind systems dominate the trade winds, these deserts are less stable than other deserts. Winter fogs, produced by upwelling cold currents, frequently blanket coastal deserts and block solar radiation.

Coastal deserts are relatively complex because they are at the juncture of terrestrial, oceanic, and atmospheric systems. A coastal desert, the Atacama of South America, is the Earth's driest desert. In the Atacama, measurable rainfall--1 millimeter or more of rain--may occur as infrequently as once every 5-20 years. Crescent-shaped dunes are common in coastal deserts such as the Namib, Africa, with prevailing onshore winds. Low clouds cover parts of the Namib in this space shuttle photo. High dunes of the Namib desert near Sossus Viei (photograph by Georg Gerster). Morning fog moistens the dunes of the Namib coastal desert (photograph by Georg Gerster). Monsoon deserts "Monsoon," derived from an Arabic word for "season," refers to a wind system with pronounced seasonal reversal. Monsoons develop in response to temperature variations between continents and oceans. The southeast trade winds of the Indian Ocean, for example, provide heavy summer rains in India as they move onshore. As the monsoon crosses India, it loses moisture on the eastern slopes of the Aravalli Range.

The Rajasthan Desert of India and the Thar Desert of Pakistan are parts of a monsoon desert region west of the ranqe. The Indus River floodplain, lower left, is the western border of the Thar Desert. This Landsat image of the monsoon desert shows small patches of sand sheets in the upper right, with three types of dunes; some dunes are almost 3 kilometers long. Polar deserts Polar deserts are areas with annual precipitation less than 250 millimeters and a mean temperature during the warmest month of less than 10° C. Polar deserts on the Earth cover nearly 5 million square kilometers and are mostly bedrock or gravel plains. Sand dunes are not prominent features in these deserts, but snow dunes occur commonly in areas where precipitation is locally more abundant. Temperature changes in polar deserts frequently cross the freezing point of water. This "freeze-thaw" alternation forms patterned textures on the ground, as much as 5 meters in diameter. The Dry Valleys of Antarctica have been ice-free for thousands of years (courtesy of USGS Image Processing Facility. Flagstaff. Arizona).

Paleodeserts Data on ancient sand seas (vast regions of sand dunes), changing lake basins, archaeology, and vegetation analyses indicate that climatic conditions have changed considerably over vast areas of the Earth in the recent geologic past. During the last 12,500 years, for example, parts of the deserts were more arid than they are today. About 10 percent of the land between 30? N. and 30? S. is covered now by sand seas. Nearly 18,000 years ago, sand seas in two vast belts occupied almost 50 percent of this land area. As is the case today, tropical rain forests and savannahs were between the two belts. Fossil desert sediments that are as much as 500 million years old have been found in many parts of the world. Sand dune-like patterns have been recognized in presently nonarid environments. Many such relict dunes now receive from 80 to 150 millimeters of rain each year. Some ancient dunes are in areas now occupied by tropical rain forests.

The Nebraska Sand Hills is an inactive 57,000square kilometer dune field in central Nebraska. The largest sand sea in the Western Hemisphere, it is now stabilized by vegetation and receives about 500 millimeters of rain each year. Dunes in the Sand Hills are up to 120 meters high. This aerial photograph of the Nebraska Sand Hills paleodesert shows a well-preserved crescent-shaped dune (or barchan) about 60 to 75 meters high. (Photograph by Thomas S. Ahlbrandt) A dry community of vegetation grows among the dunes of the Nebraska Sand Hills. (Photograph by N.H. Darton) Extraterrestrial deserts Mars is the only other planet on which we have identified wind-shaped (eolian) features. Although its surface atmospheric pressure is only about one-hundredth that of Earth, global circulation patterns on Mars have formed a circumpolar sand sea of more than five million square kilometers, an area greater than the Empty Quarter of Saudi Arabia, the largest sand sea on our planet. Martian sand seas consist predominantly of crescent-shaped dunes on plains near the perennial ice cap of the north polar area.

Smaller dune fields occupy the floors of many large craters in the polar regions. This Viking spacecraft image of Mars shows alternating layers of ice and windblown dust near the north polar cap. Annual and other periodic climatic changes due to orbit fluctuations may occur on Mars (courtesy of USGS Image Processing Facility, Flagstaff, Arizona). One of the first images taken at the Viking 2 landing site on Mars shows the pink sky over Utopia and the desert pavement on the ground (courtesy of NASA). Some of the crescent-shaped dunes in this Viking image of Mars are more than a kilometer wide. The dark material that streaks from the horn-shaped features may be dust recently blown from the dunes (courtesy of NASA). This page is < Namib | desert, Africa | Britannica.com desert, Africa Namaqualand Namib, Portuguese Namibe , a cool coastal desert extending for 1,200 miles (1,900 km) along the Atlantic coast from Namibe (formerly Moçâmedes) in Angola southward across Namibia to the Olifants River in the Western Cape province of South Africa .

It reaches inland 80 to 100 miles (130 to 160 km) to the foot of the Great Escarpment . The southern portion merges with the Kalahari on the plateau atop the escarpment. Its name is derived from the Nama language, implying “an area where there is nothing.” Sand dunes and vegetation at Sossusvlei in the Namib desert, Namibia. © Digital Vision/Getty Images Physical features of southern Africa. Encyclopædia Britannica, Inc. The diverse landscapes and wildlife of the Namib desert, Namibia. © Martin Harvey (A Britannica Publishing Partner) The Namib is arid and is almost totally uninhabited, except for a small number of scattered towns. It is important because of the trade routes that cross it, its mineral deposits, the fisheries of the bordering sea, and its increasing utilization for recreational purposes. Physical features The Namib is divided into three successive north–south-trending strips: the very narrow coastal region along the Atlantic, strongly subject to marine influences; the Outer Namib, occupying the rest of the western half of the desert; and the Inner Namib, constituting the eastern portion.

The boundaries between them consist of broad transition zones. Physiography The desert basically consists of a relatively smooth platform of truncated bedrock of various types and ages. Mica - schist and other metamorphics and granite and similar intrusives predominate. The platform rises gradually from the coast to about 3,000 feet (900 metres) at the foot of the Great Escarpment. Scattered isolated mountains rise steeply and abruptly above the platform, and in the northern half several streams have carved deep steep-walled gorges into it. Namib desert, Namibia. Moçâmedes Desert In much of the southern half of the desert the platform is surmounted by a vast expanse of sand—yellow-gray near the coast and brick red inland—which is derived from the Orange River and from other rivers that flow westward from the escarpment but never reach the sea. The dunes run in lines from north-northwest to south-southeast, individual dunes having lengths of 10 to 20 miles (16 to 32 km) and reaching heights of 200 to 800 feet (60 to 240 metres).

The troughs between these lines of dunes are interrupted by smaller transverse dunes. The extreme southern coastal area consists of wind-scoured bedrock and a few rapidly moving crescent-shaped barchans (i.e., dunes convex to the wind). The northern third—the Kaokoveld region—consists of gravel plains and rock platforms occurring between scattered rugged mountains, interspersed with a few large dune fields. Drainage Being an almost rainless area, the Namib has a poorly developed and fragmentary drainage pattern. Water from the interior plateau flows through or into the desert. In the northern half the larger streams reach the sea, but between the Kuiseb and the Orange rivers every stream terminates in a vlei (salt pan or mud flat) against or among the dunes. Sand dunes surrounding Sossusvlei, the termination of the Tsauchab, an intermittent stream in … Paul Freestone/Robert Harding Picture Library A portion of the water of major streams seeps through the sands of the streambeds. The underflow of the Kuiseb River has been tapped 25 miles (40 km) inland to provide water supplies for the towns of Walvis Bay and Swakopmund .

A pipeline 80 miles (130 km) long supplies the town of Lüderitz with water from the seepage of the Koichab, a stream that terminates in the dunes. Only the Cunene (Kunene) and Orange rivers flow permanently on the surface. Other streams have surface flow only after heavy rainfall in the interior plateaus; they normally flow for no more than a few days in several years. Soils Africa at Random: Fact or Fiction? Large areas of the Namib are completely soilless, with bedrock at the surface. Other areas are covered with shifting sand. Soils that do occur are often highly saline, impregnated with gypsum, or cemented firmly by calcium carbonate, the latter forming a calcrete layer just below the surface. Arable soils in the Namib are limited to floodplains and the terraces of major rivers and are subject to occasional inundation. Climate Ringling Bros. Folds Its Tent The coastal area is almost totally rainless, yet its air is almost always at or near the saturation point. The cold Benguela Current flows northward along the coast, chilling the air above it and thus producing fog .

This cool air moves inland as a southwest sea breeze, creating a temperature inversion about 1,000 feet (300 metres) thick, with fog below and hot, dry air above. At the coast there is little difference in temperature between day and night or between winter and summer. Temperatures are usually between 50 and 60 °F (10 and 16 °C). Along the inland margins, summer temperatures normally reach the upper 80s F (low 30s C). Only in areas sheltered from the cooling sea breeze (lee sides of mountains and bottoms of canyons) do temperatures frequently approach those expected in low-latitude deserts—i.e., in excess of 100 °F (38 °C). Freezing temperatures occur occasionally along the inner edge of the desert. A few days each year, usually in fall or spring, berg (mountain) winds blowing from the east bring high temperatures (above 100 °F), together with dry air and clouds of dust, across the desert to the coast itself. The rare rains occur usually as short-lived torrential thunderstorms.

Average annual precipitation is generally about 0.5 inch (13 mm) at the coast, increasing inland until it reaches 2 inches (51 mm) at the foot of the escarpment. In some years, however, no rain falls at all. Dew, on the other hand, is heavy and for some types of vegetation is more important than the rainfall. In the extreme south, some winter precipitation occurs from frontal storms passing farther south over the Cape region; on rare occasions, snow may fall on the higher southern mountains. Plant life Six vegetational regions are found in the Namib: (1) the coastal region, with highly succulent vegetation, which uses moisture derived from the fog, (2) the almost completely barren Outer Namib, (3) the steppes of the Inner Namib, which in many years are barren but which in wet years are covered with short grasses, both annual and perennial , (4) the dunes of the Inner Namib, which produce a surprisingly rich flora of bushes and tall grasses, (5) the larger river channels, along which large trees, particularly acacias, grow, and (6) the southern winter rainfall area, where a succulent bush growth occurs.

A curious Namib plant is the tumboa, or welwitschia ( Welwitschia mirabilis ), whose two gigantic leaves sprawl over the surface of the ground from the crest of its huge root crown (see Welwitschiaceae ). Animal life Namib Desert | Namibia Namib Desert Resources The Namib Desert is often referred to as the world's oldest desert and has been in existence for some 43 million years, remaining unchanged in its present form for the last 2 million years. The Namib is an immense expanse of relentlessly moving gravel plains and dunes of all shapes and sizes that stretch along the entire coastline. The most widespread and dominant type of desert sand dune are linear dunes, with crescent shaped dunes common along the coast and clusters of star dunes, such as the towering horseshoe of dunes at Sossusvlei , found in the eastern reaches of the sand sea. It comes as no surprise therefore to discover that the entire western section of Namibia is comprised of the Namib, which spreads beyond the borders of Namibia and flows into southern Angola and the northern Cape Province of South Africa.

With ephemeral rivers flowing unexpectedly across an ancient landscape, its dunes, plains, rivers and a foggy coast have all become vital components to support an outstanding and fascinating array of bizarre desert flora and fauna. Evidence of humans living in the Namib through time extends back to the early stone age era. But perhaps the most documented of mankind's existence can still be seen today in the many rock paintings , stone circles, tools and pottery that have been discovered over the centuries. The most famous rock paintings are at Brandberg and Twyfelfontein . The Topnaar are a well-known clan of long term residents of the Namib. More famous for living in the Namib-Naukluft Park, there are at least a dozen villages scattered along the lower Kuiseb River today. A section of the central Namib Desert incorporates the Namib Naukluft Park, the largest park in Namibia and the 3rd largest on the African continent. The present day park is a combination of the Namib Desert Park and the Naukluft Mountain Zebra Park as well as sections of the Diamond Area.

The combined area is just under 50,000km², from Luderitz to the Swakop River some 400kms. Its main attractions are Sossusvlei, Sandwich Harbour and the Naukluft hiking and four wheel drive trails The Naukluft Mountain section of the park was initially created as a sanctuary for the Hartmann's mountain zebra . There is also an interesting historical back story to the region as they were the base of Hendrik Witbooi , an important player in the history of Namibia . The celebrated freedom fighter terrorized German Colonizers at every opportunity from his well protected mountain strongholds. In recognition of his exploits, Hendrik is fondly remembered with portraits on Namibian bank notes, an honour he shares with the founding father of Namibia, Sam Nujoma . The harsh environment of the park challenges man and mammal alike. Carnivores are no exception and 3 of the larger species – black-backed jackal, brown hyena and spotted hyena have adapted to life in the desert.

Spotted hyena live in the central and eastern regions, travelling in small groups where gemsbok, mountain zebra and occasionally Namib feral horses are taken. Black-backed jackals often scout the beaches in large groups for marine carrion, Cape fur seal pups and breeding birds. Brown hyena search for smaller items of food, usually alone and also take seal pups, eat insects and fruit as well gemsbok and springbok carcasses. Mountain zebra, chacma baboons , kudu, klipspringer, Cape fox , gerbils, steenbok and a healthy population of leopard are also resident. Reptiles such as lizards and geckos, the sand snake and the side-winding adder inhabit this long, narrow wilderness. Smaller still are the scorpions , spiders, fishmoths and beetles that have adapted over centuries to survive in the dune dynamics of the desert. Insects use a swimming motion to travel through the sand beneath the surface, others dig burrows whilst certain adaptations such as shovel-snouts, protective eyelids and tubular nostrils allow other lizards to live below the surface. Hiking around Naukluft Mountains is a very rewarding wildlife experience.

As the mountains themselves touch the southern limits of Damaraland and the northern extremes of the Karoo, several bird species such as Herero chat , Karoo lark, Karoo scrub robin , cinnamon-breasted warbler, lesser honeyguide , pearl-spotted owlet, rockrunner, black-headed canary and Monteiro's hornbill can be found here. Namaqua sandgrouse gather in the morning at waterholes in their hundreds, the Karoo eremomela can be seen along the hilly areas of the escarpment and water in the rivers attract amongst other the rosy-faced lovebird. The riverine forests of the Swakop and Kuiseb Rivers entice pririt batis, swallow-tailed bee-eater and long-billed crombec. Sossusvlei in the Namib Desert is the one attraction that should not be missed while you are in Namibia; the dunes are amazing and even though this is a popular tourist destination it is still easy to gain a sense of solitude while climbing one of the dunes or walking to Dead or Hidden Vlei.

The Namib Desert section of the Namib-Naukluft Park also includes the Swakop and Kuiseb River Canyons. Vegetation and wildlife are seemingly scarce in any desert and this is one of the most harshest environments in Namibia. Wild flowers in the Namib Desert can be defined as growing in the following areas: The southern Namib - is characterized by winter rainfall and succulent plants falling into the northernmost extension of the Succulent Karoo biome of southern Africa, notably from the Orange River in the south and to the coastal town of Luderitz further north. The central Namib - an area confined by the Atlantic Ocean in the west and the escarpment to the east, sandwiched between the Kuiseb River in the south and Huab River in the north. The central Namib provides a number of habitats for plants, notably expansive gravel and gypsum plains, rocky outcrops and dry river courses with associated drainage lines. The northern Namib – is a very dry place with low and unpredictable ranges and amounts of rainfall varying from zero to over 100mm. Rain and the chances of it become less towards the coast.

It is fog that provides reliable moisture and as with the central Namib area, a fog belt can stretch some 20 and 30 km inland and on occasions further inland. Unique meteorological phenomenon distinguishes the Namib from all other deserts. In the southern Namib, continuous high wind speeds are channelled through valleys. They batter the landscape without respite, forcing the surface of the earth to become uncharacteristically dry. In particular, the Sperrgebiet experiences the highest wind speeds ever recorded on earth. Erratic annual rainfall compounds the regional aridity. Rain can only fall over the Namib Desert when warm, moist air is blown onto the eastern side of the African subcontinent by south-east trade winds. It is highly seasonal and coincides with weak South Atlantic anticyclone activity. Coastal fog regulates the climatic extremes. Desert rainfall is sporadic and unpredictable. Fog isn't. It is a most reliable source of moisture and although the amount of water captured from a blanket of fog is relatively small, plants and animals have adapted to the amounts on offer. But like rain, it is life-giving.

Over and above these constraints, the southern Namib is home to over 600 species of plants, the central Namib 400 species and some 1,000 species in the northern Namib. Despite being starved of water for most of the year, succulents and shrubs still survive in ridges and valley floors during periods of extremely windy conditions. For people wanting to experience a sense of Namibia's vastness a few nights at one of the campsites at Kuiseb Bridge, Homeb, Mirabib, Bloedkoppie, Ganab, Vogelfederberg or Kriess-se-Russhould prove to be very exhilarating. All of these camp sites offer very basic facilities, and as they do not have receptions or shops (or even game wardens) a permit is required to visit them. On the coast Sandwich Harbour is a paradise for ornithologists and nature lovers visiting Namibia. The lagoon is fed by fresh water and is a sanctuary for large numbers of coastal birds. Sandwich Harbour is only accessible by four wheel drive vehicles due to the large Namib Desert sand-dunes that meet the Atlantic Ocean.

Angling is not permitted from January 25 to April 15, camping is not permitted in the area. Visitors to Swakopmund should take time to visit the Welwitschia trail. This drive through the Namib Desert takes a few hours and visits the Moon Landscape, the Welwitschia Plains and the Namib desert oasis of Goanikontes. The route has several numbered beacons which identify areas of particular interest. A map and brochure as well as permits to visit the area should be obtained from the MET office in Swakopmund. Other notable tourist destinations in the Namib Desert include the Cape fur seal colony at Cape Cross, Fish River Canyon, the ghost town at Kolmanskop, Luderitz, the NamibRand Nature Reserve, the Orange River and the Skeleton Coast. View more pictures: Plants and animals - The Namib Desert The Namib Desert Animals and Plants Producers Trees, such as the Camelthorn or Ringwood trees, are not abundant in the Namib. The Welwitschia mirabilis is a famous plant in the Namib due to its brown color and wideness. It adapts to the sun and heat with its growth in thickness of stem instead of height.

It can live for up to 2,000 years, and grow up to 24 feet wide. Herbs have a short lifespan in the Namib, however they are very adaptable, so they can survive in this biome. Grasses are much less abundant in the desert than in the rest of Namibia other than the spiny cladoraphis. Bushes are restricted by the desert heat. The plants of the namib are some of the most interesting in the world! Welwitschia mirabilis Consumers The Gemsbok is an interesting species in the desert of Namibia. They are part of the antelope species, and a brown coat, similar to that of the sand in the desert. They are often hunted for these horns, and can run very fast. Their adaptions to the desert include their small stature, and their ability to avoid drinking water for weeks by not sweating. The Golden Mole, a very small, furry animal, is a primary consumer in this ecosystem. They can anticipate attacks on them, but are still endangered due to hunting by jackals. These animals live underground - they burrow to escape the sun.

The Namib Desert Viper, a 20 cm, commonly built viper, reside in this biome. They are high venomous snakes use camouflage to trick prey. The Meerkats are small, desert creatures which travel in clans. They have curved phalanges in order to enhance their digging abilities, to burrow. Their burrowing allowed them to escape the sun. Another adaption they have is their immunity to scorpions, which are desert creatures as well. The Namib Desert beetle is a unique beetle, which lives in the driest regions of the biome. They have long, thin legs, and bumpy outer wings. They are able to obtain sufficient water by climbing to high peaks of dunes, and facing into the breeze. Moisture from the fog then accumulates onto the bumpy wings of the beetle, and, when developed to a sufficient size, will roll down the beetle's angled back to their mouth. Various other, common animals in the Namib include lions, warthogs, and ants. Keystone species A keystone species is a species which, while not necessarily the most abundant in an environment, plays a key role within the environment.

In the Namib desert, the Camel Thorn tree fills one of the roles as a keystone species. Due to the lack of trees overall in this desert, the presence of these plants is beneficial to multiple organisms. Shade and shelter for animals is provided, as an escape from constant, intense sunlight. It is also available for bird nesting. However, a unique role that classifies this as a keystone species is the Camel Thorn's facilitation of seed dispersal. Plant life is not abundant in the desert biome, so any aid in the spread of seeds is beneficial. Predator-Prey relationships A predator-prey relationship in the Namib desert is exemplified between the black backed jackal and Cape fur seal pups by the coast. The jackals often travel in large groups while on hunting missions, making it nearly impossible for the pups to escape when unprotected, which they often are. Only the pup's mother is there to guard all of her offspring, resulting in an easier hunt for the group of predators. Because the black backed jackal has a strong reliance on readily available food sources, it is not limited by the pups as food, except partially in coastal packs. The pups are also limited by predators in the form of hyenas.

Therefore, if the jackals were, for some reason, to stop hunting the pups, or if coastal jackal population decreased, the pups would most likely go through somewhat of a population increase. Other than the seal pups, hyenas of the Namib desert also prey on the gemsbok. Particularly the brown hyena, which is more prominent in this area, is known for preying on this animal. Though the gemsbok is a fast creature, it also uses its large, curled horns to protect itself. This could be the reason that the calves, underdeveloped and less equipped, are more often chosen by the hyenas as prey, accounting for the gemsbok species' high mortality rate at a young age. This makes the gemsbok a Type III species. Trophic efficiency pyramid Africa: Namibia | Ecoregions | WWF x Deserts and xeric shrublands Africa: Namibia This extremely arid ecoregion comprises shifting sand dunes, gravel plains and rugged mountains. The world's oldest desert, the Namib Desert has existed for at least 55 million years, completely devoid of surface water but bisected by several dry riverbeds.

These riverbeds are vegetated and are home to a few ungulates, such as Hartmann’s zebras. The south of the desert is extremely dry and even lacks dry riverbeds; gemsbok is the only large mammal to occur in this harsh environment. Thick fogs are frequent along the coast and are the life-blood of the desert, providing enough moisture for a number of interesting, highly-adapted animal species to survive. The Namib Desert is well protected in a series of National Parks, Recreation Areas and Protected Diamond Areas. The diamond areas require more formal protection when the lease on these areas expires in 2020. Scientific Code Description Location and General Description The Namib Desert ecoregion extends along the coastal plain of western Namibia, from the Uniab River in the north to the town of Luderitz in the south. It extends inland from the Atlantic Coastline to the foot of the Namib Escarpment, a distance of between 80 and 200 km.

The ecoregion can be divided into two areas: the Central Namib (from the Uniab to the Kuiseb Rivers) and the Southern Namib (from the Kuiseb River to the town of Luderitz). In the north, the Central Namib merges with the Northern Namib or Kaokoveld Desert ecoregion, and in the south it merges with the Succulent Karoo ecoregion, which extends up the west coast of South Africa. A climatic transition belt crosses the coastline north of Walvis Bay in Namibia, and divides the coastal area into a northern area receiving summer rainfall, considered the Kaokoveld Desert ecoregion and a southern area receiving winter rain (the Namib Desert ecoregion). The narrow strip of land within this transition belt (about 50 km) is the most arid area in southern Africa and receives sporadic, unpredictable rainfall without a clear seasonal pattern (Williamson 1997). The most important climatic feature of the Namib Desert is its sparse and highly unpredictable annual rainfall. The annual mean ranges from 5 mm in the west to about 85 mm along its eastern limits (Lovegrove 1993).

There is extraordinary variation in rainfall between years, with the driest areas of the desert having the highest variation. The low rainfall of the Namib has two causes. Firstly, the easterly trade winds emerging over the Indian Ocean lose most of their humidity when rising over the eastern escarpment of the Drakensberg Mountains in South Africa. On their way over the continent, they lose further moisture and reach the western escarpment of Namibia warm and dry. These air masses move down onto the low-lying Namib and produce extremely hot and dry winds. Secondly, the prevailing local southwesterly winds, cooled down by the Benguela current along the west coast of South Africa, produce an inland movement of cold air, which is overlain by the warmer, lighter air. This inversion prevents the convectional rise of the cool, humid air and thus no clouds are formed (von Willert et al. 1992). The cool air does, however, regularly form a stable layer of fog, which is blown inland as far as 50 km.

This coastal fog is the life-blood in the Namib and is an important factor contributing to the remarkably high diversity of animal life in this extremely arid environment (Lovegrove 1993). Based on coastal fog, the Namib can be divided into three areas running from west to east: coastal, central, and inland. The coastal area has a mean annual rainfall of 2 to 20 mm and has thick fog on more than 180 days of the year. Air temperatures are low as a result of the cool air coming off the Benguela Current, and daily and seasonal temperature changes are minimal, with daily highs and lows differing by as little as 2° to 5 °C (Barnard 1998). Up to about 50 km inland the mean annual rainfall increases from 20 mm to 50 mm. Fog, while still important to desert organisms, occurs on only about 40 days in the year. Still further inland, fog is rare, and the mean annual rainfall increases from 50 mm to a maximum of 85 mm in places.

Daily and seasonal temperatures increase sharply and become highly variable, with temperatures of below 0° and above 50°C recorded at one location (von Willert et al.1992). One of the more characteristic features of the Namib Desert is its severe paucity of surface water. The Southern and Central Namib are bisected by ephemeral rivers that are normally dry and flow at irregular intervals, the most important of which is the Kuiseb River (Jacobson et al. 1995). On the rare occasions that this river does flow, its passage to the sea is blocked by sand dunes. The only temporarily flowing rivers to occasionally reach the ocean are the Swakop River and the Omaruru River (north of Swakopmund). Between Luderitz and the Kuiseb Rivers, the Southern Namib is made up of a belt of sand dunes 320 km long and about 120 km wide. These spectacular linear and crescent-shaped dunes reach elevations of 300 m. A strip of low sand hummocks of about 2 m high runs between this sea of dunes and the ocean.

The dunes march northwards, driven by prevailing southerly winds, and are then brought to an abrupt halt by vegetation of the Kuiseb riverbed, which forms a wind barrier. To the north of the Kuiseb River, the dunes give way to the gravel plains of the Central Namib that are dotted with inselbergs of granite and limestone (Lovegrove 1993, Barnard 1998). The formation of true soils with well-defined profiles is absent because of the low moisture status of the region (von Willert et al. 1992). The soils are made of raw minerals and are sandy and sometimes calcareous or with calcareous crusts, composed of particles in a wide range of sizes. Salt crusts are common on the soil close to the ocean, and the soils are brackish as far as the inland limit of coastal fog. Characteristic soils of the ecoregion include arenosols and weakly developed shallow Halomorphic soils (Barnard 1998). Gypsum accumulations are also characteristic of the ecoregion, particularly in the Central and Southern Namib areas (Pallett 1995).

The Southern Namib is an expansive area of large, shifting dunes. This area is botanically unexplored but is believed to be largely devoid of vegetation (Giess 1971, White 1983, Lovegrove 1993). The few species known to sparsely vegetate the dunes are the perennial grasses Stipagrostis sabulicola and S. gonostachys as well as Monsonia ignorata and the succulent Trianthema hereroensis. These perennial plants are found dotted on the lower slopes of the dunes and have adapted to the constantly shifting sands. Hummocks are formed between these sand dunes and the coast. These are formed by the nara plant, the pencil plant (Arthraerua leubnitziae) and the dollar plant (Zygophyllum stapfii) (Giess 1971, Werger 1978, White 1983). To the north of this is the Central Namib. A narrow strip of vegetation (up to 200 m wide) follows the Central Namib coastline north of the Swakop River.

A common feature of this strip are dwarf shrubs filled with sand between their branches, such as Psilocaulon salicornioides, Zygophyllum clavatum, Salsola aphylla, and S. nollothensis. At rocky sites a variety of dwarf shrubs grow, including Drosanthemum luderitzii, Ruschia sedoides, and Tetragonia arbusculoides as well as the annual grasses Stipagrostis hermannii, S. namibiensis, and S. subacaulis. Inland from this strip of vegetation are vast gravel plains that are largely devoid of vegetation except for fields of colorful lichens, including the species Teloschistes flavicans, Parmelia convoluta, and Usnea spp. Some of these lichens are not attached to any substrate and are known as vagrant lichens or Wanderflechten. Examples of these are Xanthomaculina convoluta and Parmelia hueana (Wessels 1989). Towards the extreme east, the gravel plains become more vegetated with annuals (mostly Stipagrostis species) as the predominant life form.

These annuals, which lie dormant through extended drought periods as seeds, grow rapidly after a rainfall of anything more than about 20 mm and transform the landscape into a sea of grass. Widely scattered shrubs, mainly the African moringo (Moringo ovalifolia), Euphorbia virosa and species of Commiphora, are also present on rocky outcrops on these plains (Giess 1971;Werger 1978; White 1983). A dense growth of Sporobolus robustus or more open communities of Eragrostis spinosa are found along dry riverbeds within the ecoregion. Trees of Acacia erioloba are also scattered along the riverbeds. Along the Swartkop and Kuiseb Rivers the A. erioloba forms dense stands with Acacia albida, wild tamarisk (Tamarix usneoides), the mustard tree (Salvadora persica), and the exotic Nicotiana glauca, native to South America (White 1983).

Biodiversity Features The Namib Desert is believed to be the world’s oldest desert and it has been arid for at least 55 million years (Barnard 1998). The convergence of the Benguela upwelling and the hot interior have maintained, and perhaps increased this aridity in recent times, but they did not generate the aridity. The region, isolated between the ocean and the escarpment, is considered to be a constant island of aridity surrounded by a sea of climatic change (Armstrong 1990). The arid conditions probably started with the continental split of West Gondwana 130 million to 145 million years ago when this area shifted to its present position along the Tropic of Capricorn. This lengthy dry period has had a profound influence on the region’s biodiversity. The region has remained a relatively stable center for the evolution of desert species. This has resulted in a unique array of biodiversity with high levels of endemism and numerous advanced adaptations to arid conditions.

The monotypic Welwitschia mirabilis, one of the most remarkable plants in the world, is endemic to the Namib Desert and to the Kaokoveld Desert ecoregion to the north. The distribution of this relict gymnosperm extends from the Kuiseb River in Namibia to Namibe in southern Angola (White 1983). These plants are usually found more than 20 m apart, in broad flat channels on gravel plains. The channels are so shallow as to be barely discernable, but receive floodsheet waters from higher areas during the infrequent rains. The soil becomes moist to about 1.5 m and this subsurface moisture can be retained for years. Welwitschia plants are up to 1.5 m tall and have two fibrous, straplike leaves, which persist throughout the entire life of the plant and curl into fantastic shapes on the ground. They are the longest-lived leaves of any member of the plant kingdom. It is estimated that the largest Welwitschia plants are about 2,500 years old (White 1983, Armstrong 1990, Lovegrove 1993).

In the animals the high species richness and endemism is made up largely of reptiles. They have evolved adaptations to survive in this harsh environment when most birds and large mammals have not. There are almost 70 reptile species in the ecoregion, of which more than 25 are considered endemic to the ecoregion. Five of these are strictly-endemic to the dry Namib Desert, and at least 20 species are regarded as nearly endemic to the ecoregion (WWF database). Several endemic reptiles, including two desert lizards, the wedge-snouted sand lizard (Meroles cuneirostris) and the small-scaled sand lizard (M. micropholidotus), the barking gecko (Ptenopus kochi) and the day gecko (Rhoptropus bradfieldi) are unusual in that they all dive beneath the sand to escape danger (Branch 1998). The Namib Desert is home to a large number of small rodent species that occur among the rocky habitats in the western deserts, in the sand dunes and in the vegetation of the gravel plains.

The gerbil, Gerbillurus tytonis is restricted to the southern portion of the ecoregion (WWF database). Grant’s golden mole (Eremitalpa granti VU) is near-endemic in the Namib Desert, its range extending down into South Africa. This eyeless mole is well-adapted to the desert, able to swim through the loose, dry sands of the Namib dunes. The Namaqua dune molerat (Bathyergus janetta LR) is also near-endemic in the Namib Desert, as are two bat species; the Namib long-eared bat (Laephotis namibensis EN) and the Angola wing-gland bat (Myotis seabrai VU) (Hilton-Taylor 2000). Larger ungulates are scarce in the Namib Desert, with only gemsbok (Oryx gazella LR) and springbok (Antidorcas marsupialis LR) present (Griffin 1998). Hartmann’s zebra (Equus zebra hartmannae EN) is found in the extreme east of the desert, in the transition belt between the desert and the escarpment.

However, they do move further into the desert along vegetated riverbeds (Joubert and Mostert 1975). Gemsbok are the most widespread ungulates in the desert habitat and can survive for weeks without drinking by ceasing to sweat when deprived of water. At such times, their body temperature may reach as high as 45°C, and can be sustained at this level through the heat of the day by a network of fine blood vessels at the base of the brain that exchanges heat to prevent brain damage (Armstrong 1990). The predators of the Namib Desert are cheetahs (Acinonyx jubatus, VU), brown hyenas (Hyaena brunnea, LR) and spotted hyenas (Crocuta crocuta), Cape foxes (Vulpes chama) and bat-eared foxes (Otocyon megalotis). Brown hyenas are common around Luderitz, and this area supports the highest density of this species in Namibia (Pallett 1995).

Klipspringers (Oreotragus oreotragus), steenboks (Raphicerus campestris), baboons (Papio ursinus) and leopards (Panthera pardus) occur along the courses of the Kuiseb and Swakop Rivers (Lovegrove 1993). Many species have become locally extinct in the southern areas of the Namib Desert. Lions (Panthera leo), elephants (Loxodonta africana), black rhinos (Diceros bicornis), white rhinos (Ceratotherium simum), giraffes (Giraffa camelopardalis) and hippos (Hippopotamus amphibius) were all shot out by colonial settlers who established themselves along the Orange River. The lower Orange River was once famous for its large numbers of hippos, which came onshore to graze on the floodplains at night (Pallett 1995). The desert does not have a very high level of avian richness, with only 180 species recorded to date.

This is due to the extremely arid terrain and a lack of rivers, with even ephemeral rivers absent in the southern part. The most prominent bird found in the desert is the ostrich (Struthio camelus). Most of the bird life is concentrated along the coastline. The isolated Sandvis area (previously known as Sandwich Harbor) situated on the coast at about 23°S is an area of high species richness. To date, the number of species recorded at Sandvis is 113 and represents a wide taxonomic variety (Berry and Berry 1975). Six birds are considered endemic to the Namib Desert: the dune lark (Certhilauda erythrochalamys), Benguela long-billed lark (C. benguelensis) (Ryan et al. 1999), Gray’s lark (Ammomanes grayi), bank cormorant (Phalacrocorax neglectus), tractrac chat (Cercomela tractrac), and Rüppell’s korhaan (Eupodotis rueppellii).

The dune lark is strictly endemic to this ecoregion while the gray’s lark, Rüppell’s korhaan, and C. benguelensis are found only in this ecoregion and the Kaokoveld Desert ecoregion. The Namib Desert is best known for its high species richness of beetles, particularly those belonging to the family Tenebrionidae (Lovegrove 1993). Many of these have evolved methods of condensing fog as a source of water. The head-standing beetle (Onymacris unguicularis) for example, creeps to the crest of a dune when fog is present. It then faces into the wind and stretches its back legs so that its body tilts forward, head down. As fog precipitates onto its body and runs down into its mouth the beetle drinks (Armstrong 1990). A curious feature of the Namib Desert is circles on the ground that are accentuated by abrupt changes in the vegetation pattern. These circles, known as "fairy rings" are most noticeable from the air.

They occur on the eastern fringes of the desert from southern Angola all the way through this ecoregion, characteristically within the Stipagrostis grassland community. The origin of these circles has generated interest and speculation for centuries (Lovegrove 1993). Various hypotheses have been advanced for their formation, from geomorphological phenomena, to plants having allelopathic exclusion effects, to being animal derived features. A similar phenomenon occurs to the south of the Orange River in the form of heuweltjies (originally termitaria) that are about 30 m in diameter and 1 m high. Recent evidence has shown that the harvester termite Microhodotermes viator most likely creates these heuweltjies. It is now thought that the fairy rings of the Namib Desert are created through a similar process by one of three possible termite species: Hodotermes mossambicus, Psammotermes allocerus, or Baucaliotermes hainsei (Moll 1994).

Current Status The present conservation status of the Namib Desert is good as most of the ecoregion is intact and is protected in extensive conservation blocks (Maggs et al. 1998). The Namib-Naukluft National Park (49,768 km2) is the largest conservation area in southern Africa and protects the central area of this ecoregion. The park runs from Swakopmund in the north to Luderitz in the south. The southern part of the park is taken up by the large expanse known as Diamond Area No. 2, to which public entry is strictly prohibited. The park covers gravel plains, the dune sea, the eastern semi-desert and the Kuiseb River and is therefore a good representation of the Central and Southern Namib vegetations (du Plessis 1992). The well-known Soussusvlei is located within this park and is surrounded by the highest sand dunes in the world. The vlei itself is a large shallow hollow that fills with water during the infrequent rains (Stuart and Stuart 1992).

To the north of the Namib-Naukluft National Park lies the National West Coast Tourist Recreation Area. This area extends for 180 km up the coast and is under less stringent protection than the national parks. The Cape Cross Seal Reserve is located within this area and protects one of the largest colonies of Cape fur seals (Arctocephalus pusillus) in southern Africa. Between 80,000 and 100,000 seals live on the rocks here. Types and Severity of Threats A major threat to the Namib Desert is the impact of off-road driving. The impact is the greatest on the gravel plains where depressions left by vehicles remain for more than 40 years because the rainfall is too episodic and sparse to erase them. These tracks are unsightly and cause long-lasting damage to the lichen fields. Lichens are particularly sensitive to mechanical damage as they grow extremely slowly and cannot quickly repair damaged thalli. Most of the damage is done by mining company vehicles when on prospecting expeditions (Lovegrove 1993). The major threat to the Namib-Naukluft National Park is the drop in the water table along the Kuiseb River.

This is caused primarily by the extraction of ground water by the Department of Water Affairs at two sites near Walvis Bay (Lovegrove 1993). The extracted water supplies the domestic consumption of Walvis Bay and Swakopmund and the enormous demands made by the Rossing Uranium Mine near Swakopmund. At present, the Department of Water Affairs is trying to meet the requirements for water by prospecting for more underground water sources. If water were to be found, roads, pipelines and powerlines would have to be constructed through the most pristine dune desert in the world (Lovegrove 1993). The Kuiseb River and the vegetation within it acts as a windbreak to the southerly winds, retarding the northwards movement of the dune sea onto the gravel plains. The destruction of this natural barrier would have serious ecological consequences in this part of the Namib Desert (Lovegrove 1993). Another threat to the Namib-Naukluft Park is the Topnaar pastoralists who graze large herds of goats and small groups of donkeys over the Kuiseb Riverbed and along the edge of the dunes.

The livestock have overgrazed the understory plant growth and fallen Acacia seedpods of the riverbed and are competing for food with wild animals, such as gemsboks. Collectors of succulent plant species are also having an impact on the flora to the south of the ecoregion. Illegal trade in species such as the halfmens Pachypodium namaquanum is thought to be considerable (Maggs et al. 1998). Justification of Ecoregion Delineation The Namib Desert is nested within the ‘Namib’ biogeographical province of Udvardy (1975) and the ‘Namib Desert’ unit of White (1983), with the eastern boundary taken from the 100 mm rainfall isohyet. The northern limit is at the Huab River, which a geographic boundary (Giess 1971) between the summer rainfall (northern) and winter rainfall (southern) deserts along this coastline. The southern portion of White’s ‘Namib Desert’ unit, although referred to as the southern Namib, shares affinities with the Succulent Karoo.

Thus, the portion south of Luderitz, Namibia was appended to the Succulent Karoo ecoregion. References Armstrong, S. 1990. Fog, wind and heat: life in the Namib desert. New Scientist, vol 127. 14 July: 46 - 50. Barnard, P., editor. 1998. Biological Diversity in Namibia. Namibian National Biodiversity Task Force, Directorate of Environmental Affairs, Windhoek. Barnard, P., C.J. Brown, A.M. Jarvis, and A. Robertson. 1998. Extending the Namibian protected areas network to safeguard hotspots of endemism and diversity. Biodiversity and Conservation 7: 531-547. Berry, H.H., and C.U. Berry. 1975. A checklist and notes on the birds of Sandvis, South West Africa. Madoqua 9(2): 5-18. Branch, B. 1998. Field guide to the snakes and other reptiles of southern Africa. Struik, Cape Town. Du Plessis, W.

1992. In situ conservation in Namibia: the role of national parks and nature reserves. Dintera 23: 132-141. Giess, W. 1971. A preliminary vegetation map of South West Africa. Dintera 4: 1-114. Griffin, M. 1998. The species diversity, distribution and conservation of Namibian mammals. Biodiversity and Conservation 7: 483-494. Hilton-Taylor, C. 2000. 2000 IUCN Red List of Threatened Species. IUCN, Gland, Switzerland and Cambridge, United Kingdom. Jacobson, P.J., K.M. Jacobson, and M.K. Seely. 1995. Ephemeral rivers and their catchments: sustaining people and development in western Namibia. Desert Research Foundation of Namibia, Windhoek. Joubert, E., and P. K. N. Mostert. 1975. Distribution patterns and status of mammals in South West Africa. Madoqua 9(1): 8-22. Lovegrove, B.

1993. The Living Deserts of Southern Africa. Fernwood Press, Vlaeberg Maggs, G.L., H.H. Kolberg, and C.J.H. Hines. 1994. Botanical diversity in Namibia – an overview. Pages 93 – 104 in B.J. Huntley, editor. Botanical Diversity in Southern Africa: Strelitzia, Vol 1. Maggs, G.L., P. Craven, and H.H. Kolberg. 1998. Plant species richness, endemism, and genetic resources in Namibia. Biodiversity and Conservation 7: 435-446. Moll, E.J. 1994. The origin and disribution of fairy rings in Namibia. Pages 1203-1209 in Proceedings of the XIIIth Plenery Meeting of AETFAT, Malawi. Pallett, J., editor. 1995. The Sperrgebiet: Namibia’s least known wilderness. An environmental profile of the Sperrgebiet or Diamond Area 1, in southwestern Namibia.

DRFN and NAMDEB, Windhoek, 84 pp. Ryan, P.G., I. Hood, P. Bloomer, J. Komen and T. Crowe 1999. Barlow's Lark: a new species in the Karoo Lark Certhilauda albescens complex. Ibis 140: 605-619. Stuart, C., and T. Stuart. 1992. Guide to Southern African Game and Nature Reserves. Struik, Cape Town. Udvardy, M.D.F. A classification of the biogeographical provinces of the world. IUCN Occasional Paper No. 18 (International Union of Conservation of Nature and Natural Resources, Morges, Switzerland, 1975). Von Willert, D.J., B.M. Eller, M.J.A. Werger, E. Brinckmann, and H.D. Ihlenfeldt. 1992. Life Strategies of Succulents in Deserts. Cambridge University Press. Werger, M.J.A. 1978. Biogeography and Ecology of Southern Africa.

Junk, The Hague. Wessels, D.C.J. 1989. Lichens of the Namib Desert, Namibia. Dintera 20: 3-28. White, F. 1983. The vegetation of Africa, a descriptive memoir to accompany the UNESCO/AETFAT/UNSO Vegetation Map of Africa (3 Plates, Northwestern Africa, Northeastern Africa, and Southern Africa, 1:5,000,000). UNESCO, Paris. Williamson, G. 1997. Preliminary account of the floristic zones of the Sperregebiet (Protected Diamond Area) in southwest Namibia. Dintera 25: 1-68. Prepared by: Amy Spriggs Desert types | Deserts | Earth processes | OneGeology Kids | eXtra | OneGeology Earth processes Get involved Desert types Deserts are dry places where little rain or snow falls. Some deserts get less than 25 mm (1 inch) of precipitation each year. Other deserts may get up to 250 mm (10 inches) of precipitation. Cold deserts form at higher latitudes.

The Patagonian desert in South America and the Gobi desert in Asia are cold deserts. Hot deserts are found in large bands that straddle the Tropic of Cancer and the Tropic of Capricorn, either side of the equator. The Sahara and Kalahari deserts in Africa are hot deserts. What are some other hot deserts? shows the 25 largest deserts in the world. Blue icons are cold deserts, orange are hot. How many deserts can you name? Deserts can form for many reasons The Mojave and Great Basin deserts in North America are dry because they are in the rain shadow of the California coastal mountain range. Moist air is blown from the oceans up the side of the mountains where it rains and snows. By the time the air has crossed the mountains there is very little moisture left. Click to view larger and see the legend. As air is forced upward over the mountains, it cools, causing water vapour to condense and rain falls out Wet climate National Geographic Magazine - NGM.com By Priit J.

Vesilind Photographs by Joel Sartore Dust flies as shepherds herd goats above an irrigated valley near the Atacama Desert, a 600-mile (1,000-kilometer) stretch of northern Chile squeezed between the Pacific and the Andes. Irrigation soaks up about 15 percent of available water in the Atacama, known as the driest place on Earth. In some spots, rainfall has never been recorded. The child sits upright, knees bent, wearing woolen garments and a black, four-pointed, finely woven hat topped with a small feather. Alongside lie a basket of small corncobs, a knotted string bag, and a grub hoe carved from a llama jawbone. Brown braided hair peeks out from behind a metal mask that was meant to ward off evil spirits in the afterlife. Before archaeologists discovered this tiny corpse in 1985, the Atacama Desert sun had baked its exposed tomb for more than 500 years.

The mummy—one of several hundred that have been discovered along the Chilean coast—is part of a culture squeezed between the Pacific and the Andes that once scratched out life in a land where life simply shouldn't exist. Stretching 600 miles (966 kilometers) from Peru's southern border into northern Chile, the Atacama Desert rises from a thin coastal shelf to the pampas—virtually lifeless plains that dip down to river gorges layered with mineral sediments from the Andes. The pampas bevel up to the altiplano, the foothills of the Andes, where alluvial salt pans give way to lofty white-capped volcanoes that march along the continental divide, reaching 20,000 feet (6,096 meters). At its center, a place climatologists call absolute desert, the Atacama is known as the driest place on Earth. There are sterile, intimidating stretches where rain has never been recorded, at least as long as humans have measured it. You won't see a blade of grass or cactus stump, not a lizard, not a gnat. But you will see the remains of most everything left behind.

The desert may be a heartless killer, but it's a sympathetic conservator. Without moisture, nothing rots. Everything turns into artifacts. Even little children. It is a shock then to learn that more than a million people live in the Atacama today. They crowd into coastal cities, mining compounds, fishing villages, and oasis towns. International teams of astronomers—perched in observatories on the Atacama's coastal range—probe the cosmos through perfectly clear skies. Determined farmers in the far north grow olives, tomatoes, and cucumbers with drip-irrigation systems, culling scarce water from aquifers. In the altiplano, the descendants of the region's pre-Columbian natives (mostly Aymara and Atacama Indians) herd llamas and alpacas and grow crops with water from snowmelt streams. To the far south, in the Chilean capital of Santiago, urbanites still consider the desert a wasteland, impervious to environmental damage. Rumors persist that in the mid-1980s the government proposed creating a dumpsite for the world's nuclear wastes in the Atacama, but backtracked to avoid a public relations disaster.

"There's a prejudice and lack of knowledge about the desert," complains Patricio Fischer, a biology teacher in Iquique, one of the northern cities. "People see the Atacama as a blank spot on the map." That blank spot on the map—roughly covering the Chilean regions of El Norte Chico and El Norte Grande, or Little North and Big North—has been the unlikely engine of much of the nation's wealth for the past century, luring legions of ambitious workers to the area during a series of economic booms. Newcomers began to arrive in the late 1800s, when nitrates were first exploited in the Atacama Desert. By the 1930s artificial nitrates had been developed, and the Chilean nitrate industry soon collapsed. Today copper, silver, gold, and iron mining drive the economy. More recently the Atacama has become a popular destination for European ecotourists and Santiago's adventuresome elite, triggering yet another economic rush. In the Atacama's three largest coastal cities—Arica, Iquique, and Antofagasta—there are fancy shopping centers with bowling alleys and movie theaters.

A glitzy beach scene materializes every summer in Arica, when hordes of vacationers arrive from landlocked Bolivia. Many come lugging golf clubs, intent on playing at one of three courses in the Atacama. Entrepreneurs have laid out fairways and greens in the sand: There's no grass, and swaths of blue paint on the rocks demark "water hazards." Meanwhile, competing natural gas companies are bringing power to the Atacama's copper mines and sprouting cities. Pipelines draw fresh water from the Andes to the coast. A new highway, the Paso de Jama, now spans the mountains to connect Bolivia, Paraguay, Argentina, and Uruguay to the desert ports, which ship copper and other minerals to a growing Asian market. With so much unchecked growth—urban expansion, modernization, the influx of new industry, and a burgeoning tourist trade—might there be a lasting, detrimental effect on a place many believe is infinitely resilient? Will the desert shrug off man's incursions, no worse for wear?

To find out, I crisscross the Atacama for four weeks with Sergio Ballivian, my guide and translator, a Bolivian-born adventurer who relishes the Atacama's ruggedness. In a four-wheel-drive SUV we motor north to south from Arica to Vallenar, from the boisterous surf to the silence of the pampas, through the thin winds of the Andes, through a science fiction landscape. I want to learn how life survives, even thrives, where it should not. Assessing Environmental Sensitivity Areas to Desertification in North of Iran "The low-quality vegetation surfaces occur predominately in southern part of the region, but move upward to northern parts representing ongoing decline of vegetation in the study area. Factors such as growing population, environmental pollutions, forest fire, exploitation of natural lands for agriculture and overgrazing which represents human activities are the main factors underlying desertification and land degradation (Brandt & Thornes 1996; Breckle et al. 2002; Hostert et al. 2003; Geist & Lambin 2004; Yassoglou & Kosmas 1997).

Although, in recent decades, climate change has been also considered as a predominant factor causing rapid decline of ecosystem biomass and leading to desertification in semi-arid ecosystems (Nicholson 2002; Allen et al. 2003). " [Show abstract] [Hide abstract] ABSTRACT: The sensitivity map to desertification of Chehel-chai basin (North of Iran) has been elaborated by the crossing of fives criteria including climate, water erosion, soil, vegetation, and management, which have the main impact on the evolutionary process of desertification. The methodology is resulted from the desertification model of MEDALUS, which use qualitative index to define the land sensitive area to desertification. According to the factorial scaling technique, score-ranging from 1(good condition) to 2(deteriorated condition) is assigned to each indicator. Each index was assessed based on selected indicators, which resulted in qualitative mapping of each index based on geometric average of the indicators. Thematic databases, with a 1:50000 scale resolution, were integrated and elaborated in GIS software based on arc view3.2, Ilwis3.1 and ArcGIS9.3.

The obtained results indicate that 39.39% of Chehel-chai basin is highly sensitive to desertification, 2.13 % has moderate sensitivity, only 2.43% has low sensitivity and 56.05% is non-sensitive. Studying the mean weight of numerical value, it is distinguished that the intensity of desertification for the total area is 1.32 which is classified as fragile (2). Full-text · Article · Dec 2015 Assessing Environmental Sensitivity Areas to Desertification in Eastern Algeria using Mediterranean Desertification and Land Use “MEDALUS” Model "Human activities such as pollution, fire forest, exploitation of natural lands for agriculture and overgrazing have been the main factors triggering desertification and land degradation [8, 9, 18].

However recently, the main factors that cause drastic change in landscape and rapid lose of ecosystem biomass and accordingly lead to desertification in semi-arid ecosystems are climate [19], drought with extreme heat events [13], growing population [18], overgrazing [18, 20] and conversion of land to farmlands [21]… ESAI is a very useful and easy-to-apply for determining deferent classes of vulnerable areas to desertification, which can lead to irreversible processes [6], [8]. This model gives a reliable results and it is more advantageous than other methods because of its accuracy, particular weighting of layers, use of geographical information systems in overlaying of maps, use of geometric mean than arithmetic one or sum in computing indices and final desertification map [8, 11]. " [Show abstract] [Hide abstract] ABSTRACT: The sensitivity map to desertification of Eastern Algeria (Aures region) has been elaborated by the crossing of four thematic layers (vegetation, climate, soil and the socioeconomic states), which have the main impact on the evolutionary process of desertification.

The followed methodology is inspired from the desertification model MEDALUS (Mediterranean Desertification And Land Use), which use qualitative index to define the land zones sensitive to desertification. Cartographical information of vegetation, climate variation, soil and the socioeconomic states obtained from cartographic data were transformed to numerical data then seized on, structured and managed by an algorithm dedicated to a geographical information system. Moreover, ALSAT-1 satellite images, geologic and soil maps were used as main sources for calculating the index of Environmental Sensitivity Areas (ESAI) for desertification. Besides, the main goal of this study is to identify places with different sensitivity to land degradation in Aures region (East Algeria) by means of a modeling approach developed in the European Commission funded MEDALUS project, which identifies such areas on the basis of an index (ESA index, Environmental Sensitive Area index) in which environmental quality (climate, vegetation, soil) as well as anthropogenic factors (management) are included as weighted layers.

Full-text · Article · Sep 2010 Dynamic Causal Patterns of Desertification "Our results do not reflect irreducible complexity (Dregne 2002, Warren 2002); on the contrary, they reveal distinct patterns. Nor do they identify a single cause responsible for an irreversible extension of desert landforms and landscapes (Breckle et al. 2002, Le Houérou 2002 ), be it irrational land management by nomadic pastoralists, growing population, macroeconomic forces, unjust class and power relations, or climatic factors. Rather, we identified multiplicity as the most common theme reported: multiple agents; multiple uses of land; multiple responses to social, climatic, and ecological changes; multiple spatial and temporal scales in the causes of and responses to desertification; multiple connections in social and geographical space; and multiple ties between people and land in dryland areas (Rindfuss et al. 2003 ).

" [Show abstract] [Hide abstract] ABSTRACT: Using a meta-analytical research design, we analyzed subnational case studies (n = 132) on the causes of dryland degradation, also referred to as desertification, to determine whether the proximate causes and underlying driving forces fall into any pattern and to identify mediating factors, feedback mechanisms, cross-scalar dynamics, and typical pathways of dryland ecosystem change. Our results show that desertification is driven by a limited suite of recurrent core variables, of which the most prominent at the underlying level are climatic factors, economic factors, institutions, national policies, population growth, and remote influences. At the proximate level, these factors drive cropland expansion, overgrazing, and infrastructure extension. Identifiable regional patterns of synergies among causal factors, in combination with feedback mechanisms and regional land-use and environmental histories, make up specific pathways of land change for each region and time period. Understanding these pathways is crucial for appropriate policy interventions, which have to be fine-tuned to the region-specific dynamic patterns associated with desertification. Article · Sep 2004

Question: Negev, Atacama, and Namib are all types off what?
Answer: Deserts