Geography of Sudan
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Sudan is located in Northeast Africa. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the southwest, Chad to the west and Libya to the northwest. Sudan is the third largest country in Africa, after Algeria and the Democratic Republic of the Congo. It was the largest country on the continent until South Sudan split off from it in 2011.
Geographical regions
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Northern Sudan –lying between the Egyptian border and Sennar– has two distinct parts, the desert and the Nile Valley.<ref name="regions">Template:Citation-attribution Though published in 2015, this work covers events in the whole of Sudan (including present-day South Sudan) until the 2011 secession of South Sudan.</ref> To the east of the Nile is the Nubian Desert and to the west, the Libyan Desert.<ref name="regions" /> Both are stony, with sandy dunes drifting over the landscape.<ref name="regions" /> There is virtually no rainfall in these deserts.<ref name="regions" /> Water in the Libyan desert is limited to a few small watering holes, such as Bir an Natrun, where the water table reaches the surface to form wells that provide water for nomads, caravans, and administrative patrols, although insufficient to support an oasis and inadequate to provide for a settled population.<ref name="regions" /> The Nubian Desert has no oases.<ref name="regions" /> Flowing through the desert is the Nile Valley, whose alluvial strip of habitable land is no more than two kilometers wide and whose productivity depends on the annual flood.<ref name="regions" />
Sudan's western front encompasses the regions known as Darfur and Kurdufan that comprise 850,000 square kilometers.<ref name="regions" /> Traditionally, this has been regarded as a single regional unit despite the physical differences.<ref name="regions" /> The dominant feature throughout this immense area is the absence of perennial streams; thus, people and animals must remain within reach of permanent wells.<ref name="regions" /> Consequently, the population is sparse and unevenly distributed.<ref name="regions" /> Western Darfur is an undulating plain dominated by the volcanic massif of Jabal Marrah towering 900 meters above the Sudanic plain; the drainage from Jabal Marrah onto the plain can support a settled population and a variety of wildlife (see East Saharan montane xeric woodlands).<ref name="regions" /> Western Darfur stands in contrast to northern and eastern Darfur, which are semi-deserts with little water either from the intermittent streams known as wadis or from wells that normally go dry during the winter months.<ref name="regions" /> Northwest of Darfur and continuing into Chad lies the unusual region called the jizzu, where sporadic winter rains generated from the Mediterranean frequently provide excellent grazing into January or even February.<ref name="regions" /> The southern region of western Sudan is known as the qoz, a land of sand dunes that in the rainy season is characterized by a rolling mantle of grass and has more reliable sources of water with its bore holes and hafri (sing., hafr) than does the north.<ref name="regions" /> A unique feature of western Sudan is the Nuba mountain range of southeast Kurdufan in the center of the country, a conglomerate of isolated dome-shaped, sugarloaf hills that ascend steeply and abruptly from the great Sudanic plain.<ref name="regions" /> Many hills are isolated and extend only a few square kilometers, but there are several large hill masses with internal valleys that cut through the mountains high above the plain.<ref name="regions" />
Sudan's third distinct region is the central clay plains that stretch eastward from the Nuba Mountains to the Ethiopian border, broken only by the Ingessana Hills, and from Khartoum in the north to the far reaches of southern Sudan.<ref name="regions" /> Between the Dindar and the Rahad rivers, a low ridge slopes down from the Ethiopian highlands contrasting the neighboring plains as do the occasional hills.<ref name="regions" /> The central clay plains provide the backbone of Sudan's economy because of the large amounts of settlements which are there due to the available water.<ref name="regions" /> In the heartland of the central clay plains lies the jazirah, (literally in Arabic "peninsula") the land between the Blue Nile and the White Nile where the great Gezira Scheme was developed.<ref name="regions" /> This project grows cotton for export and has historically produced more than half of Sudan's revenue and export earnings.<ref name="regions" />
Northeast of the central clay plains lies eastern Sudan, which is divided between desert and semi-desert and includes the Butana, the Qash Delta, the Red Sea Hills, and the coastal plain.<ref name="regions" /> The Butana is an undulating land between Khartoum and Kassala that provides good grazing for cattle, sheep, and goats.<ref name="regions" /> East of the Butana is a geological formation known as the Qash Delta.<ref name="regions" /> Originally a depression, it has been filled with sand and silt brought down by the flash floods of the Qash River, creating a delta above the surrounding plain.<ref name="regions" /> Extending 100 kilometers north of Kassala, the whole area watered by the Qash is a rich grassland with bountiful cultivation long after the river has spent its waters on the surface of its delta.<ref name="regions" /> Trees and bushes provide grazing for the camels from the north, and the rich moist soil provides an abundance of food crops and cotton.<ref name="regions" />
Northward beyond the Qash lie the Red Sea Hills.<ref name="regions" /> Dry, bleak, and cooler than the surrounding land, particularly in the heat of the Sudanese summer, they stretch northward into Egypt, a jumbled mass of hills where life is hard and unpredictable for the Beja inhabitants.<ref name="regions" /> Below the hills sprawls the coastal plain of the Red Sea, varying in width from about fifty-six kilometers in the south near Tawkar to about twenty-four kilometers near the Egyptian border.<ref name="regions" /> The coastal plain is dry and barren.<ref name="regions" /> It consists of rocks, and the seaward side is thick with coral reefs.<ref name="regions" />
Islands
[edit]Sudan has islands located in the Nile<ref>Template:Cite web</ref> and other rivers, in lakes and reservoirs and in the Red Sea.
River Islands
[edit]Tuti Island, Aba Island, Badien Island, Sai Island.
Red Sea Islands
[edit]Dungunab Bay
[edit]Mukawwar Island (Jazirat Magarsam), Jazirat Mayteb, Jazirat Bayer, Juzur Telat.
Talla Talla, Kebir Island, Taimashiya Island, Dar Ah Teras, Andi Seli, Masamarhu Island, Abu Isa Island, Dahrat ed Dak Hillat Island, Ed Dom esh Sheikh Island, Darrakah, Miyum, Zahrat Ghab, Jazirat Zahrat Abid, Gazirat Iri, Sayl Bahr, Gazirat Abid, Gazirat Wahman, Jaza'ir Amarat, Quban Island, Bakiyai Islands, Gazair Hayyis Wa Karai, Saqir Island, Sumar Island, Long Island, Gap Island, Two Islands.
Lake and Reservoir Islands
[edit]Roseires Reservoir
[edit]Jazirat Maqanza, Jazirat Abu Ushar, Jazirat Muluwwa.
Jebel Aulia Reservoir
[edit]Gazerat Jene't.
Er Rahad Lake
[edit]Four small islands and several islets.
Political geography
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Template:Main Sudan is divided into 18 states and one area with special administrative status. The states of Sudan are: Template:Div col
- Khartoum
- North Kordofan
- Northern
- Kassala
- Blue Nile
- North Darfur
- South Darfur
- South Kordofan
- Gezira
- White Nile
- River Nile
- Red Sea
- Al Qadarif
- Sennar
- West Darfur
- Central Darfur
- East Darfur
- West Kordofan (disestablished in 2005; reestablished in 2013)<ref name="auto1">Template:Cite web</ref><ref name="auto">Template:Cite web</ref>
As a result of the Comprehensive Peace Agreement signed in 2005, the Abyei Area was given special administrative status and following the independence of South Sudan in 2011, is considered to be simultaneously part of both the Republic of Sudan and the Republic of South Sudan, effectively a condominium.
Soil
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The country's soils can be divided geographically into a few groups, the sandy soils of the northern and west central areas, the clay soils of the central region, and the laterite soils of the south.<ref name="loc2015">Template:Citation-attribution Though published in 2015, this work covers events in the whole of Sudan (including present-day South Sudan) until the 2011 secession of South Sudan.</ref> Less extensive and widely separated, but of major economic importance, is another group consisting of alluvial soils found along the lower reaches of the White Nile and Blue Nile, along the Nile to Lake Nubia, in the delta of the Qash River in the Kassala area, and in the Baraka Delta in the area of Tawkar near the Red Sea in Kassala State.<ref name="loc2015" />
Agriculturally, the most important soils are the clays in central Sudan that extend from west of Kassala and southern Kurdufan.<ref name="loc2015" /> They are known as cracking soils because of the practice of allowing them to dry out and crack during the dry months to restore their permeability and are used in Al Jazirah and Khashm al Qirbah for irrigated cultivation.<ref name="loc2015" /> East of the Blue Nile, large areas are used for mechanized rainfed crops.<ref name="loc2015" /> West of the White Nile, these soils are used by traditional cultivators to grow sorghum, sesame, peanuts, and (in the area around the Nuba Mountains) cotton.<ref name="loc2015" /> The southern part of the clay soil zone lies in the broad floodplain of the upper reaches of the White Nile and its tributaries, covering most of Aali an Nil and upper Bahr al Ghazal in South Sudan.<ref name="loc2015" /> Subject to heavy rainfall during the rainy season, the floodplain proper is inundated for four to six months — a large swampy area, the Sudd in South Sudan, is permanently flooded — and adjacent areas are flooded for one or two months.<ref name="loc2015" /> In general this area is poorly suited to crop production, but the grasses it supports during dry periods are used for grazing.<ref name="loc2015" />
The sandy soils in the semi-arid areas south of the desert in North Kurdufan and North Darfur support vegetation used for grazing.<ref name="loc2015" /> In the southern part of these states and the West Darfur and South Darfur are the so-called qoz sands.<ref name="loc2015" /> The qoz sands are the principal area from which gum arabic is obtained through tapping of Acacia senegal (known locally as hashab). This tree grows readily in the region, and cultivators occasionally plant hashab trees when land is returned to fallow.<ref name="loc2015" /> Though livestock raising is this area's major activity, a significant amount of crop cultivation, mainly of pearl millet, also occurs.<ref name="loc2015" /> Peanuts and sesame are grown as cash crops.<ref name="loc2015" />
Hydrology
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Except for a small area in northeastern Sudan, where wadis discharge the sporadic runoff into the Red Sea and rivers from Eritrea that flow into shallow evaporating ponds west of the Red Sea Hills, the entire country is drained by the Nile and its two main tributaries, the Blue Nile and the White Nile.<ref name="hydro">Template:Citation-attribution Though published in 2015, this work covers events in the whole of Sudan (including present-day South Sudan) until the 2011 secession of South Sudan.</ref> The longest river in the world, the Nile flows for 6,737 kilometers from its farthest headwaters in Central Africa to the Mediterranean.<ref name="hydro" /> The importance of the Nile has been recognized since biblical times; for centuries the river has been a lifeline for Sudan.<ref name="hydro" />
The Blue Nile flows out of the Ethiopian highlands to meet the White Nile at Khartoum.<ref name="hydro" /> The Blue Nile is the smaller of the two rivers; its flow usually accounts for only one-sixth of the total.<ref name="hydro" /> In August, however, the rains in the Ethiopian highlands swell the Blue Nile until it accounts for 90 percent of the Nile’s total flow.<ref name="hydro" /> Sudan has constructed several dams to regulate the river’s flow, including the Roseires Dam, about 100 kilometers from the Ethiopian border and the largest, the 40-meter-high Sinnar Dam constructed in 1925 at Sinnar.<ref name="hydro" /><ref>Template:Cite web Metadata about the map is available here.</ref> The Blue Nile’s two main tributaries, the Dindar and the Rahad, have headwaters in the Ethiopian highlands and discharge water into the Blue Nile only during the summer high-water season.<ref name="hydro" /> For the remainder of the year, their flow is reduced to pools in sandy riverbeds.<ref name="hydro" />
The White Nile flows north from Central Africa, draining Lake Victoria and highland regions of Uganda, Rwanda, and Burundi.<ref name="hydro" /> South of Khartoum, the British built the Jabal al-Awliya Dam in 1937 to store the water of the White Nile and then release it in the fall when the flow from the Blue Nile slackens.<ref name="hydro" /> Much water from the reservoir has been diverted for irrigation projects in central Sudan and much of the remainder evaporates.<ref name="hydro" /> By now, silt deposits have curtailed the overall flow.<ref name="hydro" />
North of Khartoum, the Nile flows through the desert in a large S-shaped pattern to empty into Lake Nasser behind the Aswan High Dam in Egypt.<ref name="hydro" /> The river flows slowly beyond Khartoum, dropping little in elevation, although five cataracts hinder river transport at times of low water.<ref name="hydro" /> The Atbarah River, flowing out of Ethiopia, is the only tributary north of Khartoum, and its waters only reach the Nile from July to December.<ref name="hydro" /> During the rest of the year, the Atbarah’s bed is dry, except for a few pools and ponds.<ref name="hydro" />
Climate
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Although Sudan lies within the tropics, the climate ranges from hyper-arid in the north to tropical wet-and-dry in the far southwest.<ref name="climate">Template:Citation-attribution Though published in 2015, this work covers events in the whole of Sudan (including present-day South Sudan) until the 2011 secession of South Sudan.</ref> Temperatures do not vary greatly with the season at any location; the most significant climatic variables are rainfall and the length of the wet and dry seasons.<ref name="climate" /> Variations in the length of the wet and dry seasons depend on which of two air flows predominates: dry northern winds from the Sahara and the Arabian Peninsula or moist southwesterly winds from the Congo River basin and southeasterly winds from the Indian Ocean.<ref name="climate" />
From January to March, the country is under the influence of dry northeasterlies.<ref name="climate" /> There is minimal rainfall countrywide except for a small area in northwestern Sudan where the winds have passed over the Mediterranean bringing occasional light rains.<ref name="climate" /> By early April, the moist southwesterlies have reached southern Sudan, bringing heavy rains and thunderstorms.<ref name="climate" /> By July, the moist air has reached Khartoum, and in August it extends to its usual northern limits around Abu Hamad, sometimes the humid air reaches as far as the Egyptian border.<ref name="climate" /> The flow becomes weaker as it spreads north.<ref name="climate" /> In September the dry northeasterlies begin to strengthen and to push south and by the end of December they cover the entire country.<ref name="climate" /> Khartoum has a three-month rainy season (July–September) with an annual average rainfall of Template:Convert; Atbarah receives showers in August that produce an annual average of only Template:Convert.<ref name="climate" />
In some years, the arrival of the southwesterlies and their rain in central Sudan can be delayed, or they may not come at all.<ref name="climate" /> When that happens, drought and famine follow.<ref name="climate" /> The decades of the 1970s and 1980s saw the southwesterlies frequently fail, with disastrous results for the Sudanese people and economy.<ref name="climate" />
Temperatures are highest at the end of the dry season when cloudless skies and dry air allow them to soar.<ref name="climate" /> The far south, however, with only a short dry season, has uniformly high temperatures throughout the year.<ref name="climate" /> In Khartoum, the warmest months are May and June, when average highs are Template:Convert and temperatures can reach Template:Convert.<ref name="climate" /> Northern Sudan, with its short rainy season, has very high daytime temperatures year round, except for winter months in the northwest where there is some precipitation in January and February.<ref name="climate" /> Conditions in highland areas are generally cooler, and the hot daytime temperatures during the dry season throughout central and northern Sudan fall rapidly after sunset.<ref name="climate" /> Lows in Khartoum average Template:Convert in January and have dropped as low as Template:Convert after the passing of a cool front in winter.<ref name="climate" />
The haboob, a violent dust storm, can occur in central Sudan when the moist southwesterly flow first arrives (May through July).<ref name="climate" /> The moist, unstable air forms thunderstorms in the heat of the afternoon.<ref name="climate" /> The initial downflow of air from an approaching storm produces a huge yellow/red wall of sand and clay that can temporarily reduce visibility to zero.<ref name="climate" />
Desert regions in central and northern Sudan are among the driest and the sunniest places on Earth: the sunshine duration is always uninterrupted year-round and rise to above 4,000 hours or about 91% of the time with the sky being cloudless all the time.Template:Citation needed Areas around Wadi Halfa and along the Egyptian border can easily pass many years or many decades without seeing any rainfall at all.Template:Citation needed They are also among the hottest places during their summertime and their "wintertime": averages high temperatures routinely exceed 40 °C (104 °F) for four to nearly six months a year to reach a maximum peak of about 45 °C (113 °F) in some places and averages high temperature remain above 24 °C (75.2 °F) in the northernmost region and above 30 °C (86 °F) in places such as Atbara or Meroe.Template:Citation needed
Environmental issues
[edit]Sudan faces some severe environmental problems, most related either to the availability of water or its disposal.<ref name="hydro" /> Among them are desertification, land degradation, and deforestation.<ref name="hydro" /> Desertification, the southward shift of the boundary between desert and sem-idesert, has occurred at an estimated rate of 50 to 200 kilometers since records of rainfall and vegetation began in the 1930s.<ref name="hydro" /> Its impact has been most notable in North Darfur and North Kordofan.<ref name="hydro" /> Desertification is likely to continue its southward progression because of declining precipitation and will lead to continued loss of productive land.<ref name="hydro" /> Agriculture, particularly poorly planned and managed mechanized agriculture, has led to land degradation, water pollution, and related problems.<ref name="hydro" /> Land degradation has also resulted from an explosive growth in the size of livestock herds since the 1960s that have overused grazing areas.<ref name="hydro" /> Deforestation has occurred at an alarming rate.<ref name="hydro" /> Sudan as a whole might have lost nearly 12 percent of its forest cover between 1990 and 2005, or about 8.8 million hectares, a loss driven primarily by land clearance and energy needs.<ref name="hydro" />
Compounding Sudan’s environmental problems are long years of warfare and the resultant camps for large numbers of internally displaced people, who scour the surrounding land for water, fuel, and food.<ref name="hydro" /> Experts from the United Nations predict that Sudan’s current program of dam construction on the Nile and its tributaries will cause riverbank erosion and loss of fertilizing silt.<ref name="hydro" /> In urban areas, rapid and uncontrolled population influx into Khartoum and other cities and towns and the general lack of facilities to manage solid waste and sewage are among major environmental concerns.<ref name="hydro" />
Area and land use
[edit]Sudan has a land area of Template:Convert and a total area of Template:Convert.<ref name=":0">Template:Cite web</ref> Approximately Template:Convert were irrigated as of 2012.<ref name=":0" />
Land boundaries
[edit]The length of Sudan's borders are Template:Convert.<ref name=":0" /> Border countries are the Central African Republic (Template:Convert), Chad (Template:Convert), Egypt (Template:Convert), Eritrea (Template:Convert), Ethiopia (Template:Convert), Libya (Template:Convert), and South Sudan (Template:Convert).<ref name=":0" />
Natural resources
[edit]Template:See also Petroleum is Sudan's most important natural resource. The country also has significant deposits of chromium, copper, iron, mica, silver, gold, tungsten, and zinc.
See also
[edit]References
[edit]Template:Sudan topics Template:Geography of Africa Template:Africa topic