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77-464: In geological terms, the area that makes up The Cape Flats is a vast sheet of aeolian sand, ultimately of marine origin, which has blown up from the adjacent beaches over a period of a hundred thousand years. Below the sand, the bedrock is in general alternating layers of dark grey shale, siltstone and minor sandstone from a late- Precambrian rock formation called the Malmesbury Group . This

154-573: A passion gap became fashionable and remains popular today. The modification involves the removal of a person's top front teeth . The Cape Flats' political history is complex and sometimes baffling even to insiders: for instance, the politics of the Coloured communities of the Cape Flats have included Trotskyist activism in earlier years, and mobilisation for the ANC's United Democratic Front in

231-548: A British army engineer who worked in Egypt prior to World War II . Bagnold investigated the physics of particles moving through the atmosphere and deposited by wind. He recognized two basic dune types, the crescentic dune, which he called " barchan ", and the linear dune, which he called longitudinal or "seif" (Arabic for "sword"). Bagnold developed a classification scheme that included small-scale ripples and sand sheets as well as various types of dunes. Bagnold's classification

308-406: A Y-junction with the fork directed upwind. They have a sharp sinuous or en echelon crest. They are thought to form from a bimodal seasonal wind pattern, with a weak wind season characterized by wind directed an at acute angle to the prevailing winds of the strong wind season. The strong wind season produces a barchan form and the weak wind season stretches this into the linear form. Another possibility

385-413: A boulder or an isolated patch of vegetation. Here the sand builds up to the angle of repose (the maximum stable slope angle), about 34 degrees, then begins sliding down the slip face of the patch. A sandfall is a sand shadow of a cliff or escarpment. Closely related to sand shadows are sand drifts . These form downwind of a gap between obstructions, due to the funneling effect of the obstructions on

462-446: A change in the wind pattern about 3000 years ago. Complex dunes show Little lateral growth but strong vertical growth and are important sand sinks. Vegetated parabolic dunes are crescent-shaped, but the ends of the crescent point upwind, not downwind. They form from the interaction of vegetation patches with active sand sources, such as blowouts. The vegetation stabilizes the arms of the dune, and an elongated lake sometimes forms between

539-430: A critique of government policies. The Cape Flats is sometimes considered dangerous, although most communities are tight-knit, diverse and tolerant with vibrant cultures and traditions. Almost all of the communities of the Cape Flats remain, to one degree or another, poverty-stricken. Serious social problems include a high rate of unemployment and high levels of gang activity. During the late 1990s and early 2000s, there

616-531: A desert. Vegetation is effective at suppressing aeolian transport. Vegetation cover of as little as 15% is sufficient to eliminate most sand transport. The size of shore dunes is limited mostly by the amount of open space between vegetated areas. Aeolian transport from deserts plays an important role in ecosystems globally. For example, wind transports minerals from the Sahara to the Amazon basin . Saharan dust

693-418: A distinctive crescent shape with the tips of the crescent directed downwind. The dunes are widely separated by areas of bedrock or reg. Barchans migrate up to 30 meters (98 ft) per year, with the taller dunes migrating faster. Barchans first form when some minor topographic feature creates a sand patch. This grows into a sand mound, and the converging streamlines of the air flow around the mound build it into

770-503: A few) Afrikaans-speaking congregations of the Dutch Reformed Church , Rastafarian communities, people who engage only in traditional Xhosa practices, syncretic Xhosa Christian churches, evangelical Christian churches, and southern Africa's largest Muslim community (drawing its oldest roots from the historic Cape Malay community, which dates to the 17th century). In the 1940s, a type of dental modification known as

847-566: A generation. Vegetable farming persisted, but to a much lesser extent, because urbanisation enveloped vast tracts of land in short order. The first use of the Cape Flats to remove people of colour from the more central urban areas was the township of Langa , which saw large scale removal after the Natives (Urban Areas) Act of 1923 . It is the oldest township in Cape Town and was the location of much resistance to apartheid. Its origins go back to

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924-489: A lack of soil moisture and a large supply of unconsolidated sediments . Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts . The term is derived from the name of the Greek god Aeolus , the keeper of the winds. Aeolian processes are those processes of erosion , transport , and deposition of sediments that are caused by wind at or near

1001-498: A large aklé or barchanoid dune. They form over a prolonged period of time in areas of abundant sand and show a complex internal structure. Careful 3-D mapping is required to determine the morphology of a draa preserved in the geologic record. Linear dunes can be traced up to tens of kilometers, with heights sometimes in excess of 70 meters (230 ft). They are typically several hundred meters across and are spaced 1 to 2 kilometers (0.62 to 1.24 mi)apart. They sometimes coalesce at

1078-411: A network of sinuous ridges perpendicular to the wind direction. Aklé dunes are preserved in the geologic record as sandstone with large sets of cross-bedding and many reactivation surfaces. Draas are very large composite transverse dunes. They can be up to 4,000 meters (13,000 ft) across and 400 meters (1,300 ft) high and extend lengthwise for hundreds of kilometers. In form, they resemble

1155-552: A rival gang or a fellow Cape Flats resident. 34°0′S 18°40′E  /  34.000°S 18.667°E  / -34.000; 18.667 Aeolian processes Aeolian processes , also spelled eolian , pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets ). Winds may erode , transport, and deposit materials and are effective agents in regions with sparse vegetation ,

1232-405: A sheet-like surface of rock fragments that remains after wind and water have removed the fine particles. The rock mantle in desert pavements protects the underlying material from further deflation. Areas of desert pavement form the regs or stony deserts of the Sahara . These are further divided into rocky areas called hamadas and areas of small rocks and gravel called serirs . Desert pavement

1309-403: A vigorous low-latitude wind system plus more exposed continental shelf due to low sea levels. Wind-deposited sand bodies occur as ripples and other small-scale features, sand sheets , and dunes . Wind blowing on a sand surface ripples the surface into crests and troughs whose long axes are perpendicular to the wind direction. The average length of jumps during saltation corresponds to

1386-513: Is silt deposited by wind, is common in humid to subhumid climates. Much of North America and Europe are underlain by sand and loess of Pleistocene age originating from glacial outwash. The lee (downwind) side of river valleys in semiarid regions are often blanketed with sand and sand dunes. Examples in North America include the Platte , Arkansas , and Missouri Rivers. Wind erodes

1463-576: Is also important in periglacial areas, on river flood plains , and in coastal areas. Coastal winds transport significant amounts of siliciclastic and carbonate sediments inland, while wind storms and dust storms can carry clay and silt particles great distances. Wind transports much of the sediments deposited in deep ocean basins. In ergs (desert sand seas), wind is very effective at transporting grains of sand size and smaller. Particles are transported by winds through suspension, saltation (skipping or bouncing) and creeping (rolling or sliding) along

1540-479: Is also responsible for forming red clay soils in southern Europe. Dust storms are wind storms that have entrained enough dust to reduce visibility to less than 1 kilometer (0.6 mi). Most occur on the synoptic (regional) scale, due to strong winds along weather fronts , or locally from downbursts from thunderstorms. Crops , people, and possibly even climates are affected by dust storms. On Earth, dust can cross entire oceans, as occurs with dust from

1617-440: Is downwind movement of particles in a series of jumps or skips. Saltation is most important for grains of up to 2 mm in size. A saltating grain may hit other grains that jump up to continue the saltation. The grain may also hit larger grains (over 2 mm in size) that are too heavy to hop, but that slowly creep forward as they are pushed by saltating grains. Surface creep accounts for as much as 25 percent of grain movement in

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1694-502: Is except on part of the western margin between Zeekoevlei to the south and Claremont and Wetton to the north, where an intrusive mass of Cape granite is to be found. Most of the sand is unconsolidated; however, in some places near the False Bay coast the oldest sand dunes have been cemented into a soft sandstone ( calcrete ), and form low cliffs at the edge of the beach. These formations contain important fossils of animals such as

1771-552: Is extremely common in desert environments. Blowouts are hollows formed by wind deflation. Blowouts are generally small, but may be up to several kilometers in diameter. The smallest are mere dimples 0.3 meters (1 ft) deep and 3 meters (10 ft) in diameter. The largest include the blowout hollows of Mongolia, which can be 8 kilometers (5 mi) across and 60 to 100 meters (200 to 400 ft) deep. Big Hollow in Wyoming , US, extends 14 by 9.7 kilometers (9 by 6 mi) and

1848-457: Is important in semiarid and arid regions. Wind erosion is increased by some human activities, such as the use of 4x4 vehicles . Deflation is the lifting and removal of loose material from the surface by wind turbulence. It takes place by three mechanisms: traction/surface creep, saltation , and suspension. Traction or surface creep is a process of larger grains sliding or rolling across the surface. Saltation refers to particles bouncing across

1925-435: Is most applicable in areas devoid of vegetation. In 1941, John Tilton Hack added parabolic dunes, which are strongly influenced by vegetation, to the list of dune types. The discovery of dunes on Mars reinvigorated aeolian process research, which increasingly makes use of computer simulation. Wind-deposited materials hold clues to past as well as to present wind directions and intensities. These features help us understand

2002-575: Is on the Loess Plateau in China . This very same Asian dust is blown for thousands of miles, forming deep beds in places as far away as Hawaii. The Peoria Loess of North America is up to 40 meters (130 ft) thick in parts of western Iowa . The soils developed on loess are generally highly productive for agriculture. Small whirlwinds, called dust devils , are common in arid lands and are thought to be related to very intense local heating of

2079-609: Is that these dunes result from secondary flow , though the precise mechanism remains uncertain. Complex dunes (star dunes or rhourd dunes) are characterized by having more than two slip faces. They are typically 500 to 1,000 meters (1,600 to 3,300 ft) across and 50 to 300 meters (160 to 980 ft) high. They consist of a central peak with radiating crests and are thought to form where strong winds can come from any direction. Those in Gran Desierto de Altar of Mexico are thought to have formed from precursor linear dunes due to

2156-468: Is the oldest of such suburbs in Cape Town and was the location of much resistance to apartheid. Langa is also where several people were killed on 21 March 1960, the same day as the Sharpeville massacre , during the anti-pass campaign. On 21 March 2010, now 50 years later, a monument was unveiled by the government in remembrance of the people who died while on the protest march. Langa is bordered by

2233-463: Is the wearing down by collisions of particles entrained in a moving fluid. It is effective at rounding sand grains and at giving them a distinctive frosted surface texture. Collisions between windborne particles is a major source of dust in the size range of 2-5 microns. Most of this is produced by the removal of a weathered clay coating from the grains. Wind dominates the transport of sand and finer sediments in arid environments. Wind transport

2310-437: Is up to 90 meters (300 ft) deep. Abrasion (also sometimes called corrasion ) is the process of wind-driven grains knocking or wearing material off of landforms . It was once considered a major contributor to desert erosion, but by the mid-20th Century, it had come to be considered much less important. Wind can normally lift sand only a short distance, with most windborne sand remaining within 50 centimeters (20 in) of

2387-441: Is usually less than the fluid threshold. In other words, there is hysteresis in the wind transport system. Small particles may be held in the atmosphere in suspension. Turbulent air motion supports the weight of suspended particles and allows them to be transported for great distances. Wind is particularly effective at separating sediment grains under 0.05 mm in size from coarser grains as suspended particles. Saltation

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2464-678: The M17 (Jan Smuts Drive) to the west, the N2 to the south, and the M7 to the east, and is served by Langa Railway Station. Although Langa literally means "sun" in Xhosa , the name of the township is derived from the name of Langalibalele – a chief and renowned rainmaker who in 1873 was imprisoned on Robben Island for rebelling against the Natal government. Various prominent people fought for his release and he

2541-438: The wavelength , or distance between adjacent crests, of the ripples. In ripples, the coarsest materials collect at the crests causing inverse grading . This distinguishes small ripples from dunes, where the coarsest materials are generally in the troughs. This is also a distinguishing feature between water laid ripples and aeolian ripples. A sand shadow is an accumulation of sand on the downwind side of an obstruction, such as

2618-403: The windward side. The downwind portion of the dune, the lee slope, is commonly a steep avalanche slope referred to as a slipface . Dunes may have more than one slipface. The minimum height of a slipface is about 30 centimeters. Wind-blown sand moves up the gentle upwind side of the dune by saltation or creep. Sand accumulates at the brink, the top of the slipface. When the buildup of sand at

2695-495: The 19th century. During the apartheid era, race-based legislation such as the Group Areas Act and pass laws either forced non-white people out of more central urban areas designated for white people and into government-built townships in the Cape Flats, or made living in the area illegal, forcing many people into informal settlements elsewhere in the Cape Flats. Large housing projects were built here, mostly as part of

2772-572: The 80s; and then, widespread support for the historically white National Party (which had presided over apartheid) in the early post-apartheid elections. More recently, the area has seen an expansion of African National Congress strength from its base in the Black townships and into historically Coloured areas, as well as a particularly strong local growth of left-wing social movements like the Treatment Action Campaign which offer

2849-452: The Cape Flats have an increasing diversity of residents, with Xhosa-speaking people an increasingly noticeable presence in some previously mainly Afrikaans-speaking areas. Popular musicians from the area include pop singer Brenda Fassie and jazz artists Abdullah Ibrahim and Basil Coetzee , who named their song " Mannenberg " after a Cape Flats township. There is an active hip hop movement. Its religious communities include (to name only

2926-520: The Cape Flats was partly covered in wetlands, particularly during winter. Many of these have been destroyed by canalisation and infilling to provide residential space. Many of the remaining perennial vleis such as Zeekoevlei , Rondevlei and Zandvlei are at the southwest side of the region. The noted English naturalist, William John Burchell , remarked in 1811 that the deep sand of the Flats made travel by cart or wagon extremely difficult. The situation

3003-490: The Earth's surface by deflation (the removal of loose, fine-grained particles by the turbulent action of the wind) and by abrasion (the wearing down of surfaces by the grinding action and sandblasting by windborne particles). Once entrained in the wind, collisions between particles further break them down, a process called attrition . Worldwide, erosion by water is more important than erosion by wind, but wind erosion

3080-499: The Earth's total land surface. The sandy areas of today's world are somewhat anomalous. Deserts, in both the present day and in the geological record, are usually dominated by alluvial fans rather than dune fields. The present relative abundance of sandy areas may reflect reworking of Tertiary sediments following the Last Glacial Maximum. Most modern deserts have experienced extreme Quaternary climate change, and

3157-598: The N2 highway out of Cape Town. In 2005, the Guga S'thebe Arts & Culture Centre, a cultural/multi-purpose centre, was officially opened in Langa after unofficially being in operation for a number of years. The first township B&B – Ma Neo's Bed & Breakfast – was opened in Langa in 1999. On 9 July 2014, Langa was the site of violent protests against a lack of government service delivery, specifically regarding housing, but

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3234-611: The Nationalist government's larger effort to force the so-called Coloured communities and other people of Colour (mostly Xhosa) out of the central and western areas of Cape Town, which were designated as white areas under the Group Areas Act . This meant that only white people could reside there permanently, as under the apartheid system black Africans were officially made citizens of native reserves (called "homelands"), therefore having resident worker status, despite often never having been there & having spent their entire lives in

3311-675: The Sahara that reaches the Amazon Basin . Dust storms on Mars periodically engulf the entire planet. When the Mariner 9 spacecraft entered its orbit around Mars in 1971, a dust storm lasting one month covered the entire planet, thus delaying the task of photo-mapping the planet's surface. Most of the dust carried by dust storms is in the form of silt -size particles. Deposits of this windblown silt are known as loess . The thickest known deposit of loess, up to 350 meters (1,150 ft),

3388-442: The air that results in instabilities of the air mass. Dust devils may be as much as one kilometer high. Dust devils on Mars have been observed as high as 10 kilometers (6.2 mi), though this is uncommon. Wind is very effective at separating sand from silt and clay. As a result, there are distinct sandy (erg) and silty (loess) aeolian deposits, with only limited interbedding between the two. Loess deposits are found further from

3465-570: The apartheid-era pass laws. Joe Slovo , which was established in 1990, is the largest informal settlement in Langa and one of the largest in the country. It is currently being threatened with forced removals to make way for the N2 Gateway Housing Project. Some parts of the Joe Slovo informal settlement have since been removed and transformed into the N2 Gateway Housing Project (2006), which can be seen when travelling along

3542-399: The area for military exercises and the few farmers who inhabited the Flats eked out a living by growing vegetables in pockets of relatively poor soil between the barren dunes. Modern amenities were unknown; telephones were unknown, drinking water was collected in tanks from roofs and at night the rooms were lit by oil lamps. The era of sand and antelopes vanished completely in little more than

3619-556: The arms of the dune. Clay dunes are uncommon but have been found in Africa, Australia, and along the Gulf Coast of North America. These form on mud flats on the margins of saline bodies of water subject to strong prevailing winds during a dry season. Clay particles are bound into sand-sized pellets by salts and are then deposited in the dunes, where the return of the cool season allows the pellets to absorb moisture and become bound to

3696-442: The brink exceeds the angle of repose , a small avalanche of grains slides down the slipface. Grain by grain, the dune moves downwind. Dunes take three general forms. Linear dunes, also called longitudinal dunes or seifs, are aligned in the direction of the prevailing winds. Transverse dunes, which include crescent dunes (barchans), are aligned perpendicular to the prevailing winds. More complex dunes, such as star dunes, form where

3773-484: The close living conditions of residents in Langa promoted a high degree of neighbourliness and the creation of broader African institutions that promoted a greater sense of community cohesion. On 30 March 1960 Langa was the starting point for a march of between 30,000 and 50,000 protesters to Caledon Square police station in Cape Town led by Philip Kgosana and the Pan Africanist Congress to protest

3850-402: The colonial authorities. It was an era before the advent of modern technological methods for the construction of permanent roads and in those days the Cape Flats was a massive sea of unstabilised sand dunes that moved with the winds. This made travel between Cape Town and the interior very difficult, particularly for the large ox-drawn wagons of the time. The authorities decided to try to stabilise

3927-415: The directions of the winds are highly variable. Additional dune types arise from various kinds of topographic forcing, such as from isolated hills or escarpments. Transverse dunes occur in areas dominated by a single direction of the prevailing wind. In areas where sand is not abundant, transverse dunes take the form of barchans or crescent dunes. These are not common, but they are highly recognizable, with

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4004-428: The distinctive crescent shape. Growth is ultimately limited by the carrying capacity of the wind, which as the wind becomes saturated with sediments, builds up the slip face of the dune. Because barchans develop in areas of limited sand availability, they are poorly preserved in the geologic record. Where sand is more abundant, transverse dunes take the form of aklé dunes, such as those of the western Sahara. These form

4081-628: The dune surface. Deserts cover 20 to 25 percent of the modern land surface of the earth, mostly between the latitudes of 10 to 30 degrees north or south. Here the descending part of the tropical atmospheric circulation (the Hadley cell ) produces high atmospheric pressure and suppresses precipitation. Large areas of this desert is floored with windblown sand. Such areas are called ergs when they exceed about 125 square kilometers (48 sq mi) in area or dune fields when smaller. Ergs and dune fields make up about 20% of modern deserts or about 6% of

4158-505: The early years local laws prohibiting the brewing of sorghum beer (utywala) was strongly resented and in the 1930s prohibition was abolished in the area with the construction of municipal beer halls taking place in 1945. In these early years tribal and sub-tribal ethnic identities were still very strong. Often local celebrations by the Mfengu community celebrating their "liberation" from the Xhosa would lead to an increase in tensions. However,

4235-465: The extinct Cape lion and also provide evidence that stone-age people hunted here tens of thousands of years ago. To the west the expanse of the Cape Flats is limited by rising ground that slopes up to the steep cliffs of the Cape Peninsula mountain chain, while in the east the land rises gradually towards the equally rugged cliffs of Hottentots Holland mountains and other elevated regions of

4312-404: The ground. The minimum wind velocity to initiate transport is called the fluid threshold or static threshold and is the wind velocity required to begin dislodging grains from the surface. Once transport is initiated, there is a cascade effect from grains tearing loose other grains, so that transport continues until the wind velocity drops below the dynamic threshold or impact threshold , which

4389-564: The interior of the Boland . The area has a Mediterranean climate , with warm dry summers and cool, damp winters. It is generally exposed to the wind, both from the northwest (winter) and southeast (summer). Flooding can be a problem, especially in July and August. Cold wet spells, especially in August and September, can make life very difficult for those living in sub-standard housing. Historically

4466-720: The major priorities of the RDP ( Reconstruction & Development Programme ) is to build houses. Since the end of apartheid, these communities are no longer legally bound by racial restrictions; but history, language, economics and ethnic politics still contribute to homogeneity of local areas. So, for example, most residents of Mitchell's Plain likely still speak a locally inflected version of Afrikaans , along with English and either they or their parents were designated as Coloured by apartheid; most residents of Khayelitsha still speak Xhosa and English and either they or their parents were designated as Black by apartheid. Nonetheless, some areas of

4543-525: The margins of dune fields, although they also occur within ergs. Conditions that favor the formation of sand sheets, instead of dunes, may include surface cementation, a high water table, the effects of vegetation, periodic flooding, or sediments rich in grains too coarse for effective saltation. A dune is an accumulations of sediment blown by the wind into a mound or ridge . They differ from sand shadows or sand drifts in that they are independent of any topographic obstacle. Dunes have gentle upwind slopes on

4620-453: The now "designated white" regions. Since many of the mostly Xhosa workers and their families, were designated under apartheid as citizens of assigned native reserves/homelands, many who were out of formal work were obliged to live in the area illegally, further contributing to the growth of informal settlements. In addition to the extant townships of the mid-century, other large townships (such as Mitchell's Plain & Khayelitsha across

4697-610: The original source of sediments than ergs. An example of this is the Sand Hills of Nebraska , US. Here vegetation-stabilized sand dunes are found to the west and loess deposits to the east, further from the original sediment source in the Ogallala Formation at the feet of the Rocky Mountains. Some of the most significant experimental measurements on aeolian landforms were performed by Ralph Alger Bagnold ,

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4774-407: The past half a century. In 1950 the area was practically uninhabited. There was a single, narrow road across the Flats from Cape Town to The Strand that ran between walls of alien rooikrans bushes and one could travel for miles without seeing any sign of habitation other than a few fences and a handful of farmhouses. Native antelope roamed at will between the dense thickets of wattles. The army used

4851-491: The point where the South African National Defence Force had to be deployed to the gang-impacted areas of the Cape Flats to help the provincial police force deal with the increasing gang violence. Some well-known criminal organisations based in the Cape Flats include: A wide range of community empowerment organisations work non-violently to combat the poverty, crime and health problems, and

4928-460: The present climate and the forces that molded it. For example, vast inactive ergs in much of the modern world attest to late Pleistocene trade wind belts being much expanded during the Last Glacial Maximum. Ice cores show a tenfold increase in non-volcanic dust during glacial maxima. The highest dust peak in the Vostok ice cores dates to 20 to 21 thousand years ago. The abundant dust is attributed to

5005-526: The prevailing wind. They form mostly in softer material such as silts. Abrasion produces polishing and pitting, grooving, shaping, and faceting of exposed surfaces. These are widespread in arid environments but geologically insignificant. Polished or faceted surfaces called ventifacts are rare, requiring abundant sand, powerful winds, and a lack of vegetation for their formation. In parts of Antarctica wind-blown snowflakes that are technically sediments have also caused abrasion of exposed rocks. Attrition

5082-428: The road) were created on the flats in the 1970s and 1980s. Both have become among the largest residential areas in Cape Town and some of the largest in the country at large. Large scale rural-urban migration has rapidly increased the population, putting strain on housing with major increases in informal shack settlement, including in areas that were originally created on a planned basis, for example, Khayelitsha. One of

5159-498: The role of civil society in many parts of the area is relatively strong. In late 2019, South African political group, the TRAKboys began enforcing a ceasefire between the gangs in Cape Flats. Citing the repeated failure of government initiatives aimed at curbing gun violence in Cape Flats, the TRAKboys created a system of community justice and enacted harsh punishments on any gang members found to be plotting violence on any members of

5236-611: The sand with plants native to the British colonies of New South Wales and Western Australia. The earliest importation of wattles was in 1827. Massive plantings were established in the 1840s and 1850s and the work continued until well after 1875. At the time, the plan worked well enough: the march of the dunes was arrested. The price paid, in ecological terms, was that the Cape Flats was carpeted by invasive species . Serious efforts have in recent years been made to roll back this alien scourge. The Cape Flats has undergone dramatic change in

5313-537: The sediments that are now being churned by wind systems were generated in upland areas during previous pluvial (moist) periods and transported to depositional basins by stream flow. The sediments, already sorted during their initial fluvial transport, were further sorted by wind, which also sculpted the sediments into eolian landforms. Langa, Western Cape Langa is a township in Cape Town , South Africa . Its name in Xhosa means " sun ". The township

5390-613: The surface and practically none normally being carried above 2 meters (6 ft). Many desert features once attributed to wind abrasion, including wind caves, mushroom rocks , and the honeycomb weathering called tafoni , are now attributed to differential weathering, rainwash, deflation rather than abrasion, or other processes. Yardangs are one kind of desert feature that is widely attributed to wind abrasion. These are rock ridges, up to tens of meters high and kilometers long, that have been streamlined by desert winds. Yardangs characteristically show elongated furrows or grooves aligned with

5467-420: The surface for short distances. Suspended particles are fully entrained in the wind, which carries them for long distances. Saltation likely accounts for 50–70 % of deflation, while suspension accounts for 30–40 % and surface creep accounts for 5–25 %. Regions which experience intense and sustained erosion are called deflation zones. Most aeolian deflation zones are composed of desert pavement ,

5544-536: The surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as aeolian . Aeolian processes are most important in areas where there is little or no vegetation. However, aeolian deposits are not restricted to arid climates. They are also seen along shorelines; along stream courses in semiarid climates; in areas of ample sand weathered from weakly cemented sandstone outcrops; and in areas of glacial outwash . Loess , which

5621-555: The wind. Sand sheets are flat or gently undulating sandy deposits with only small surface ripples. An example is the Selima Sand Sheet in the eastern Sahara Desert, which occupies 60,000 square kilometers (23,000 sq mi) in southern Egypt and northern Sudan . This consists of a few feet of sand resting on bedrock. Sand sheets are often remarkably flat and are sometimes described as desert peneplains . Sand sheets are common in desert environments, particularly on

5698-423: Was aggravated by a widespread shortage of firewood, causing fuel collectors to cut the relatively few indigenous shrubs and trees that stabilised the sand. During the second half of the 19th century, the area was completely overrun by alien vegetation, mainly of Australian origin. The plants included hakeas and especially wattles (genus Acacia ). The principal reason for this infestation lay in decisions made by

5775-471: Was initially built in phases before being formally opened in 1927. It was developed as a result of South Africa's 1923 Urban Areas Act (more commonly known as the "pass laws"), which was designed to force Africans to move from their homes into segregated locations. Similar to Nyanga , Langa is one of the many areas in South Africa that were designated for Black Africans before the apartheid era. It

5852-575: Was significant armed conflict between various gangs and PAGAD (People Against Gangsterism and Drugs), a vigilante organisation. Post-apartheid development projects, such as the Reconstruction & Development Programme , have also led to violent conflicts within communities. As of 2014, efforts to combat gangs include Hanover Park's Ceasefire programme, where former gang members "use their experiences to mediate gang disputes and help young men and women quit gang life. The gang violence escalated to

5929-420: Was subsequently confined to a farm called "Uitvlugt", which is on the site of present-day Pinelands . Langa, which adjoins Pinelands, commemorates this folk hero as it was developed in 1898 on the land known as "Langalibalele's Location". Hence Langa is often called "Kwa-Langa" meaning "place of Langa". Langa was originally designed in a way to allow the authorities maximum visibility and control of residents. In

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