Geography of Sudan
Encyclopedia

Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. 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...

 is located in northeastern Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

. It is bordered by Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

 to the north, the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...

 to the northeast, Eritrea
Eritrea
Eritrea , officially the State of Eritrea, is a country in the Horn of Africa. Eritrea derives it's name from the Greek word Erethria, meaning 'red land'. The capital is Asmara. It is bordered by Sudan in the west, Ethiopia in the south, and Djibouti in the southeast...

 and Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

 to the east, South Sudan
South Sudan
South Sudan , officially the Republic of South Sudan, is a landlocked country located in the Sahel region of northeastern Africa. It is also part of the North Africa UN sub-region. Its current capital is Juba, which is also its largest city; the capital city is planned to be moved to the more...

 to the south, the Central African Republic
Central African Republic
The Central African Republic , is a landlocked country in Central Africa. It borders Chad in the north, Sudan in the north east, South Sudan in the east, the Democratic Republic of the Congo and the Republic of the Congo in the south, and Cameroon in the west. The CAR covers a land area of about ,...

 to the southwest, Chad
Chad
Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...

 to the west and Libya
Libya
Libya is an African country in the Maghreb region of North Africa bordered by the Mediterranean Sea to the north, Egypt to the east, Sudan to the southeast, Chad and Niger to the south, and Algeria and Tunisia to the west....

 to the northwest. It is the third largest country in Africa.

Geographic coordinates: 15°00′N 30°00′E

Land boundaries

The length of Sudan's borders is 300 kilometers.
Border countries are:
  • Central African Republic
    Central African Republic
    The Central African Republic , is a landlocked country in Central Africa. It borders Chad in the north, Sudan in the north east, South Sudan in the east, the Democratic Republic of the Congo and the Republic of the Congo in the south, and Cameroon in the west. The CAR covers a land area of about ,...

     (483 km)
  • Chad
    Chad
    Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...

     (1 360 km)
  • Egypt
    Egypt
    Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

     (1 273 km)
  • Eritrea
    Eritrea
    Eritrea , officially the State of Eritrea, is a country in the Horn of Africa. Eritrea derives it's name from the Greek word Erethria, meaning 'red land'. The capital is Asmara. It is bordered by Sudan in the west, Ethiopia in the south, and Djibouti in the southeast...

     (605 km)
  • Ethiopia
    Ethiopia
    Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

     (723 km)
  • Libya
    Libya
    Libya is an African country in the Maghreb region of North Africa bordered by the Mediterranean Sea to the north, Egypt to the east, Sudan to the southeast, Chad and Niger to the south, and Algeria and Tunisia to the west....

     (383 km)
  • South Sudan
    South Sudan
    South Sudan , officially the Republic of South Sudan, is a landlocked country located in the Sahel region of northeastern Africa. It is also part of the North Africa UN sub-region. Its current capital is Juba, which is also its largest city; the capital city is planned to be moved to the more...

     (1 937 km)

Natural resources

Petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 is Sudan's major natural resource. The country also has small deposits of chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...

 ore, copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

, iron ore, mica
Mica
The mica group of sheet silicate minerals includes several closely related materials having highly perfect basal cleavage. All are monoclinic, with a tendency towards pseudohexagonal crystals, and are similar in chemical composition...

, silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

, tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...

, and zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

.

The Nile is the dominant geographic feature of Sudan, flowing 3,000 kilometers from Uganda in the south to Egypt in the north. Most of the country lies within its catchment basin. The Blue Nile
Blue Nile
The Blue Nile is a river originating at Lake Tana in Ethiopia. With the White Nile, the river is one of the two major tributaries of the Nile...

 and the White Nile
White Nile
The White Nile is a river of Africa, one of the two main tributaries of the Nile from Egypt, the other being the Blue Nile. In the strict meaning, "White Nile" refers to the river formed at Lake No at the confluence of the Bahr al Jabal and Bahr el Ghazal rivers...

, originating in the Ethiopian highlands and the Central African lakes, respectively, join at Khartoum to form the Nile River proper that flows to Egypt. Other major tributaries of the Nile are the Bahr el Ghazal, Sobat, and Atbarah river
Atbarah River
The Atbarah River in northeast Africa rises in northwest Ethiopia, approximately 50 km north of Lake Tana and 30 km west of Gondar. It flows about 805 km to the Nile in north-central Sudan, joining it at the city of Atbarah...

s.

Land use

Sudan’s total land area amounts to some 2 510 000 km². About half of this land is suitable for agriculture, of which about 170 000 km² are actually cultivated.

1993 estimates:
5% arable land
Arable land
In geography and agriculture, arable land is land that can be used for growing crops. It includes all land under temporary crops , temporary meadows for mowing or pasture, land under market and kitchen gardens and land temporarily fallow...

0% permanent crops
  • 46% permanent pastures
  • 19% forests and woodland
  • 30% other areas

  • 19 460 km² irrigated
    Irrigation
    Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

     land

Environmental issues

Sudan suffers from inadequate supplies of potable water, declining wildlife populations because of warfare and excessive hunting, soil erosion, desertification, and periodic droughts (see Merowe Dam
Merowe Dam
The Merowe Dam, also known as Merowe High Dam, Merowe Multi-Purpose Hydro Project or Hamdab Dam, is a large dam near Merowe Town in northern Sudan, about north of the capital Khartoum. Its dimensions make it the largest contemporary hydropower project in Africa...

). For example, Sudan historically offered habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

 for the endangered Painted Hunting Dog, Lycaon pictus; however. this canid is presently deemed to be extirpated or of very limited population in Sudan, due to the pressures of the human population as well as warfare/genocide.

Geographical regions

Northern Sudan, lying between the Egyptian border and Khartoum, has two distinct parts, the desert and the Nile Valley. To the east of the Nile lies the Nubian Desert; to the west, the Libyan Desert. They are similar—stony, with sandy dune
Dune
In physical geography, a dune is a hill of sand built by wind. Dunes occur in different forms and sizes, formed by interaction with the wind. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind...

s drifting over the landscape. There is virtually no rainfall in these deserts, and in the Nubian Desert there are no oases
Oasis
In geography, an oasis or cienega is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source...

. In the west, there are a few small watering holes, such as Bir an Natrun, where the water table reaches the surface to form wells that provide water for nomad
Nomad
Nomadic people , commonly known as itinerants in modern-day contexts, are communities of people who move from one place to another, rather than settling permanently in one location. There are an estimated 30-40 million nomads in the world. Many cultures have traditionally been nomadic, but...

s, caravan
Camel train
A camel train is a series of camels carrying goods or passengers in a group as part of a regular or semi-regular service between two points. Although they rarely travelled faster than the walking speed of a man, camels' ability to handle harsh conditions made camel trains a vital part of...

s, and administrative patrols, although insufficient to support an oasis and inadequate to provide for a settled population. 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.

Western Sudan is a generic term describing the regions known as Darfur
Darfur
Darfur is a region in western Sudan. An independent sultanate for several hundred years, it was incorporated into Sudan by Anglo-Egyptian forces in 1916. The region is divided into three federal states: West Darfur, South Darfur, and North Darfur...

 and Kurdufan
Kurdufan
Kurdufan , also spelled Kordofan, is a former province of central Sudan. In 1994 it was divided into three new federal states: North Kurdufan, South Kurdufan, and West Kurdufan...

 that comprise 850,000 square kilometers. Traditionally, this has been regarded as a single regional unit despite the physical differences. The dominant feature throughout this immense area is the absence of perennial streams; thus, people and animals must remain within reach of permanent wells. Consequently, the population is sparse and unevenly distributed. 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
East Saharan montane xeric woodlands
The East Saharan montane xeric woodlands is an ecoregion of central Africa, a number of high mountains in the middle of the huge area of savanna on the edge of the Sahara Desert.-Location and description:...

). Western Darfur stands in contrast to northern and eastern Darfur, which are semidesert with little water either from the intermittent streams known as wadis or from wells that normally go dry during the winter months. 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. 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. A unique feature of western Sudan is the Nuba mountain
Nuba Mountains
Nuba Mountains is an area located in South Kordofan, Sudan. The area is home to a group of indigenous ethnic groups known collectively as the Nuba peoples. In the 18th century, Nuba Mountains became home to the kingdom of Taqali that controlled the hills of the mountains until their defeat by...

 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. 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.

Sudan's third distinct region is the central clay plains that stretch eastward from the Nuba Mountains to the Ethiopian frontier, broken only by the Ingessana Hills, and from Khartoum in the north to the far reaches of southern Sudan. Between the Dindar and the Rahad
Rahad River
The Rahad is a river of western Ethiopia, and a tributary of the Abay on the right side....

 rivers, a low ridge slopes down from the Ethiopian highlands to break the endless skyline of the plains, and the occasional hill stands out in stark relief. The central clay plains provide the backbone of Sudan's economy because they are productive where settlements cluster around available water. Furthermore, in the heartland of the central clay plains lies the jazirah
Al Jazirah (state)
Al Jazirah , also spelled Gezira, is one of the 15 states of Sudan. The state lies between the Blue Nile and the White Nile in the east-central region of the country. It has an area of 27,549 km². The name comes from the Arabic word for peninsula. Wad Madani is the capital of the state.It is...

, the land between the Blue Nile and the White Nile (literally in Arabic "peninsula") where the great Gezira Scheme
Gezira Scheme
The Gezira Scheme is one of the largest irrigation projects in the world. It is centered on the Sudanese state of Al Jazirah, just southeast of the confluence of the Blue and White Nile rivers at the city of Khartoum. The economy of Sudan was historically based on agriculture prior to the...

 (aka Jazirah Scheme) was developed. This project grows cotton for export and has traditionally produced more than half of Sudan's revenue and export earnings.

Northeast of the central clay plains lies eastern Sudan, which is divided between desert and semidesert and includes Al Butanah, the Qash Delta, the Red Sea Hills, and the coastal plain. Al Butanah is an undulating land between Khartoum and Kassala
Kassala
Kassala is the capital of the state of Kassala in eastern Sudan. Its 2008 population was recorded to be 419,030. It is a market town and is famous for its fruit gardens. It was formerly a railroad hub, however, as of 2006 there was no operational railway station in Kassala and much of the track...

 that provides good grazing for cattle, sheep, and goats. East of Al Butanah is a peculiar geological formation known as the Qash Delta. 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. 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. Trees and bushes provide grazing for the camels from the north, and the rich moist soil provides an abundance of food crops and cotton.

Northward beyond the Qash lie the more formidable Red Sea Hills. Dry, bleak, and cooler than the surrounding land, particularly in the heat of the Sudan summer, they stretch northward into Egypt, a jumbled mass of hills where life is hard and unpredictable for the hardy Beja inhabitants. 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 frontier. The coastal plain is dry and barren. It consists of rocks, and the seaward side is thick with coral reefs.

The southern clay plains, which can be regarded as an extension of the northern clay plains, extend all the way from northern Sudan to the mountains on the Sudan-Uganda frontier, and in the west from the borders of Central African Republic eastward to the Ethiopian highlands. The plain is covered with swathes of savanna
Savanna
A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...

 grassland running east to west which have different characteristics depending on the amount of rainfall they receive. These are Sahelian Acacia savanna in the north and East Sudanian savanna
East Sudanian savanna
The East Sudanian Savanna is a hot, dry, tropical savanna ecoregion of central Africa.-Location and description:This is the eastern half of the broad savanna belt which runs east and west across Africa, this section lying east of the Cameroon Highlands...

 to the south. This great Nilotic plain is broken by several distinctive features. First, the White Nile bisects the plain and provides large permanent water surfaces such as lakes Fajarial, No
Lake No
Lake No is a lake in South Sudan. It is located just north of the vast swamp of the Sudd, at the confluence of the Bahr al Jabal and Bahr el Ghazal rivers. It marks the transition between the Bahr al Jabal and White Nile proper. Lake No is located approximately 1,156 km downstream of Uganda's...

, and Shambe. Second, As Sudd
Sudd
The Sudd , also known as the Bahr al Jabal, As Sudd or Al Sudd, is a vast swamp in South Sudan, formed by the White Nile. The word “sudd” is derived from the Arabic word “sadd”, meaning “block.” The term has come to refer to any large solid floating vegetation island or mat...

 ("The Sudd"), the world's largest swamp, provides a formidable expanse of lakes, lagoons, and aquatic plants, whose area in high flood waters exceeds 30,000 square kilometers, or approximately the size of Belgium. So intractable was this sudd (see Glossary) as an obstacle to navigation that a passage was not discovered until the mid-nineteenth century. Then as now, As Sudd with its extreme rate of evaporation consumes on average more than half the waters that come down the White Nile from the equatorial lakes. These waters also create a flood plain known as the toic that provides grazing when the flood waters retreat to the permanent swamp and sluggish river, the Bahr al Jabal, as the White Nile is called here.

The land rising to the south and west of the southern clay plain is referred to as the Ironstone Plateau (Jabal Hadid), a name derived from its laterite soils and increasing elevation. The plateau rises from the west bank of the Nile, sloping gradually upward to the Congo-Nile watershed. The land is well watered, providing rich cultivation, but the streams and rivers that come down from the watershed divide and erode the land before flowing on to the Nilotic plain flow into in As Sudd. Along the streams of this Northern Congolian forest-savanna mosaic
Northern Congolian forest-savanna mosaic
The Northern Congolian forest-savanna mosaic is a forest and savanna ecoregion of central Africa, part of the belt of transitional forest-savanna mosaic that lie between Africa's equatorial forests and the tropical dry forests, savannas, and grasslands that lie to the north and south...

 are gallery forests, the beginnings of the tropical rain forests that extend far into Zaire
Zaire
The Republic of Zaire was the name of the present Democratic Republic of the Congo between 27 October 1971 and 17 May 1997. The name of Zaire derives from the , itself an adaptation of the Kongo word nzere or nzadi, or "the river that swallows all rivers".-Self-proclaimed Father of the Nation:In...

. To the east of the Jabal Hadid and the Bahr al Jabal rise the foothills of the mountain ranges along the Sudan-Uganda border — the Imatong
Imatong Mountains
The Imatong Mountains are located in the southeast of South Sudan in the state of Eastern Equatoria, and extend into Uganda. Mount Kinyeti is the highest mountain of the range at , and the highest in the whole of South Sudan....

, Didinga
Didinga Hills
The Didinga Hills are an upland area in Eastern Equatoria state of South Sudan, lying mainly within Budi County. They are named for the Didinga people who live in the region....

, and Dongotona — which rise to more than 3,000 meters. These mountains form a contrast to the great plains to the north that dominate Sudan's geography.

Sudan includes islands located in the Nile (including Aba Island
Aba Island
Aba Island is an island on the White Nile to the south of Khartoum, Sudan. It is the original home of the Mahdi in Sudan and the spiritual base of the Umma Party...

, Badien Island
Badien Island
Badien Island is one of the biggest islands in the Nile and the second biggest island in Sudan. It is Northern to Dongola the capital of the Northern State in Sudan....

, Sai Island
Saï (island)
Saï is a large island in the Nile River in Nubia between the second and third cataracts. It is 12 km long and 5.5 km wide. Saï was intermittently occupied by the Egyptians during the New Kingdom.-External links:* *...

, and, at the confluence of the Blue and White Nile, Tuti Island
Tuti Island
Tuti Island is an island in Sudan where the White Nile and Blue Nile merge to form the main Nile. It is surrounded by the "Three Towns": Khartoum , Omdurman , and Khartoum North...

) and in the Red Sea (including the Suakin Archipelago).

Soils

The country's soils can be divided geographically into three categories. These are the sandy soils of the northern and west central areas, the clay soils of the central region, and the laterite soils of the south. Less extensive and widely separated, but of major economic importance, is a fourth group consisting of alluvial soils found along the lower reaches of the White Nile and Blue Nile rivers, along the main 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 Ash Sharqi State.

Agriculturally, the most important soils are the clays in central Sudan that extend from west of Kassala through Al Awsat and southern Kurdufan. Known as cracking soils because of the practice of allowing them to dry out and crack during the dry months to restore their permeability, they are used in the areas of Al Jazirah
Al Jazirah (state)
Al Jazirah , also spelled Gezira, is one of the 15 states of Sudan. The state lies between the Blue Nile and the White Nile in the east-central region of the country. It has an area of 27,549 km². The name comes from the Arabic word for peninsula. Wad Madani is the capital of the state.It is...

 and Khashm al Qirbah for irrigated cultivation. East of the Blue Nile, large areas are used for mechanized rainfed crops. West of the White Nile, these soils are used by traditional cultivators to grow sorghum
Sorghum
Sorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...

, sesame
Sesame
Sesame is a flowering plant in the genus Sesamum. Numerous wild relatives occur in Africa and a smaller number in India. It is widely naturalized in tropical regions around the world and is cultivated for its edible seeds, which grow in pods....

, peanut
Peanut
The peanut, or groundnut , is a species in the legume or "bean" family , so it is not a nut. The peanut was probably first cultivated in the valleys of Peru. It is an annual herbaceous plant growing tall...

s, and (in the area around the Nuba Mountains) cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....

. 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 states. Subject to heavy rainfall during the rainy season, the floodplain proper is inundated for four to six months — a large swampy area, As Sudd, is permanently flooded — and adjacent areas are flooded for one or two months. In general this area is poorly suited to crop production, but the grasses it supports during dry periods are used for grazing.

The sandy soils in the semiarid areas south of the desert in northern Kurdufan and northern Darfur states support vegetation used for grazing. In the southern part of these states and the western part of southern Darfur are the so-called qoz sands. Livestock raising is this area's major activity, but a significant amount of crop cultivation, mainly of pearl millet
Pearl millet
Pearl millet is the most widely grown type of millet. Grown in Africa and the Indian subcontinent since prehistoric times, it is generally accepted that pearl millet originated in Africa and was subsequently introduced into India. The center of diversity, and suggested area of domestication, for...

, also occurs. Peanuts and sesame are grown as cash crop
Cash crop
In agriculture, a cash crop is a crop which is grown for profit.The term is used to differentiate from subsistence crops, which are those fed to the producer's own livestock or grown as food for the producer's family...

s. The qoz sands are the principal area from which gum arabic
Gum arabic
220px|thumb|right|Acacia gumGum arabic, also known as acacia gum, chaar gund, char goond, or meska, is a natural gum made of hardened sap taken from two species of the acacia tree; Acacia senegal and Acacia seyal...

 is obtained through tapping of Acacia senegal
Acacia senegal
is a small deciduous Acacia tree known by the common names Rfaudraksha, Gum Acacia, Gum Arabic Tree, or Gum Senegal Tree. It is native to semi-desert regions of Sub-Saharan Africa, as well as Oman, Pakistan, and northwestern India. It grows to a height of 5-12m, with a trunk up to 30 cm in...

 (known locally as hashab). This tree grows readily in the region, and cultivators occasionally plant hashab trees when land is returned to fallow.

The laterite
Laterite
Laterites are soil types rich in iron and aluminium, formed in hot and wet tropical areas. Nearly all laterites are rusty-red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock...

 soils of the south cover most of western Al Istiwai and Bahr al Ghazal states. They underlie the extensive moist woodlands found in these provinces. Crop production is scattered, and the soils, where cultivated, lose fertility relatively quickly; even the richer soils are usually returned to bush fallow within five years.

Climate

Although Sudan lies within the tropics, the climate ranges from arid in the north to tropical wet-and-dry in the far southwest. Temperatures do not vary greatly with the season at any location; the most significant climatic variables are rainfall and the length of the dry season. Variations in the length of the dry season depend on which of two air flows predominates, dry northeasterly winds from the Arabian Peninsula
Arabian Peninsula
The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...

 or moist southwesterly winds from the Congo River
Congo River
The Congo River is a river in Africa, and is the deepest river in the world, with measured depths in excess of . It is the second largest river in the world by volume of water discharged, though it has only one-fifth the volume of the world's largest river, the Amazon...

 basin.

From January to March, the country is under the influence of the dry north easterlies. There is practically no rainfall countrywide except for a small area in northwestern Sudan in where the winds have passed over the Mediterranean bringing occasional light rains. By early April, the moist south westerlies have reached southern Sudan, bringing heavy rains and thunderstorms. By July the moist air has reached Khartoum, and in August it extends to its usual northern limits around Ab Hamad, although in some years the humid air may even reach the Egyptian border. The flow becomes weaker as it spreads north. In September the dry north easterlies begin to strengthen and to push south and by the end of December they cover the entire country. Yambio
Yambio
-Location:The city is located in Yambio County, Western Equatoria State, in southwestern South Sudan, close to the International border with the Democratic Republic of the Congo. Its locacation lies approximately , by road, west of Juba, the lagest city in South Sudan and the capital of that country...

, close to the border with Zaire
Zaire
The Republic of Zaire was the name of the present Democratic Republic of the Congo between 27 October 1971 and 17 May 1997. The name of Zaire derives from the , itself an adaptation of the Kongo word nzere or nzadi, or "the river that swallows all rivers".-Self-proclaimed Father of the Nation:In...

, has a nine-month rainy season (April-December) and receives an average of 1142 millimetres (45 in) of rain each year; Khartoum has a three-month rainy season (July-September) with an annual average rainfall of 161 millimetres (6.3 in); Barbara receives showers in August that produce an annual average of only 74 millimetres (2.9 in).

In some years, the arrival of the south westerlies and their rain in central Sudan can be delayed, or they may not come at all. If that happens, drought and famine follow. The decades of the 1970s and 1980s saw the south westerlies frequently fail, with disastrous results for the Sudanese people and economy.

Temperatures are highest at the end of the dry season when cloudless skies and dry air allow them to soar. The far south, however, with only a short dry season, has uniformly high temperatures throughout the year. In Khartoum, the warmest months are May and June, when average highs are 41 °C (105.8 °F) and temperatures can reach 48 °C (118.4 °F). Northern Sudan, with its short rainy season, has hot daytime temperatures year round, except for winter months in the northwest where there is precipitation from the Mediterranean in January and February. 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. Lows in Khartoum average 15 °C (59 °F) in January and have dropped as low as 6 °C (42.8 °F) after the passing of a cool front in winter.

The haboob
Haboob
A haboob is a type of intense duststorm carried on an atmospheric gravity current. Haboobs are regularly observed in arid regions throughout the world. They have been observed in the Sahara desert , as well as across the Arabian Peninsula, throughout Kuwait, and in the most arid regions of Iraq...

, a violent dust storm, can occur in central Sudan when the moist southwesterly flow first arrives (May through July). The moist, unstable air forms thunderstorms in the heat of the afternoon. The initial downflow of air from an approaching storm produces a huge yellow wall of sand and clay that can temporarily reduce visibility to zero.

Extreme points

This is a list of the extreme points of Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. 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...

, the points that are farther north, south, east or west than any other location.
  • Northern-most point - an unnamed headland in the Wadi Halfa salient
    Wadi Halfa Salient
    Wadi Halfa Salient is the unofficial name of a salient of the international border between Sudan and Egypt along the Nile River to the north....

    , Northern wilayat
  • Eastern-most point - Ghab Miyun island, Suakin archipelago, Red Sea wilayat
  • Eastern-most point (mainland) - Ras Kasar
    Ras Kasar
    Ras Kasar is a cape in northeastern Africa, on border between Eritrea and Sudan at the Red Sea. It is the northernmost point in Eritrea and the easternmost point in Sudan....

    , Red Sea wilayat
  • Southern-most point - the tripoint
    Tripoint
    A tripoint, or trijunction , is a geographical point at which the borders of three countries or subnational entities meet....

     with Uganda
    Uganda
    Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...

     and the Democratic Republic of the Congo
    Democratic Republic of the Congo
    The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...

    , Central Equatoria
    Central Equatoria
    -Government:Executive*Governor - Maj. Gen. Clement Wani Konga*Deputy Governor and Minister of Education, Science and Technology - Mr. Manase Lomole Waya *Minister of Education - Lokulenge Lole Lokule...

     wilayat (Note: was the case until July 9, 2011. Following the independence of South Sudan, this location lies within South Sudan, and the southern-most point of Sudan is now further to the north)
  • Western-most point - unnamed location on the border with Chad
    Chad
    Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...

     in the Wadi Kadja immediately east of the Chadian village of Bir Kandji, West Darfur
    West Darfur
    West Darfur is one of the 15 states of Sudan, and one of three comprising the Darfur region. It has an area of 79,460 km² and an estimated population of approximately 1,007,000 . It borders North and South Darfur to the east. The Chadian prefectures of Biltine and Ouaddaï lie to the west,...

     wilayat

  • Note: Sudan claims, but not control, the Hala'ib triangle
    Hala'ib Triangle
    The Hala'ib Triangle is an area of land measuring located on the Red Sea's African coast...

     which is under Egyptian rule. If this area is included then Sudan's northern-most point is the point at which the Egyptian border enters the Red Sea
    Red Sea
    The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...

     on the mainland or, including islands, the eastern headland of Mirear Island

Line notes

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