Location: Northern Africa, bordering the Red Sea, between
Egypt and Eritrea
Geographic coordinates: 15 00 N, 30 00 E
Map references: Africa
total: 2,505,810 sq km
land: 2.376 million sq km
water: 129,810 sq km
Area - comparative: slightly more than one-quarter the size
of the US
total: 7,687 km
border countries: Central African Republic 1,165 km, Chad
1,360 km, Democratic Republic of the Congo 628 km, Egypt 1,273 km,
Eritrea 605 km, Ethiopia 1,606 km, Kenya 232 km, Libya 383 km, Uganda
Coastline: 853 km
contiguous zone: 18 nm
continental shelf: 200-m depth or to the depth of exploitation
territorial sea: 12 nm
Climate: tropical in south; arid desert in north; rainy
season (April to October)
Terrain: generally flat, featureless plain; mountains in
east and west
lowest point: Red Sea 0 m
highest point: Kinyeti 3,187 m
Natural resources: petroleum; small reserves of iron ore,
copper, chromium ore, zinc, tungsten, mica, silver, gold, hydropower
arable land: 5%
permanent crops: 0%
permanent pastures: 46%
forests and woodland: 19%
other: 30% (1993 est.)
Irrigated land: 19,460 sq km (1993 est.)
Natural hazards: dust storms
Environment - current issues: inadequate supplies of potable
water; wildlife populations threatened by excessive hunting; soil
Environment - international agreements:
party to: Biodiversity, Climate Change, Desertification,
Endangered Species, Law of the Sea, Nuclear Test Ban, Ozone Layer
signed, but not ratified: none of the selected agreements
Geography - note: largest country in Africa; dominated by
the Nile and its tributaries
Size: Total area 2,505,813 square kilometers;
land area 2,376,000 square kilometers; coastline 716 kilometers;
largest country in Africa.
Topography: Plateau and plains predominate. Mountainous
areas behind Red Sea coast, in far south, and in far west. Only
interior highlands of consequence are Nuba Mountains west of white
Nile River. All significant streams flow to White Nile and Blue
Nile rivers, which join just north of Khartoum to form River Nile.
Extensive swamps in south, especially along Bahr al Ghazal (southernmost
part of White Nile).
Climate: Rainfall ranges from rare and occasional
in far northern desert to relatively abundant and frequent (rainy
seasons of six to nine months) in southern third of Sudan. In most
years central third has enough rain for agriculture but lack of
rain in 1980s and 1991 has caused years of drought. Dust storms
(often preceding rainstorms) common in north and northern parts
of central Sudan, reducing visibility and causing much discomfort.
Mean temperatures and daily maximums generally high; desert temperatures
often quite cool at night.
Data as of June 1991
Sudan is Africa's largest country, embracing 2,505,813 square kilometers
of northeast and central Africa. It consists of a huge plain bordered
on three sides by mountains: to the east the Red Sea Hills, to the
west Jabal Marrah, and on the southern frontier the Didinga Hills
and the Dongotona and Imatong mountains. Jutting up abruptly in
the south-central region of this vast plain are the isolated Nuba
Mountains and Ingessana Hills, and far to the southeast, the lone
Boma Plateau near the Ethiopian border. Spanning eighteen degrees
of latitude, the plain of the
Sudan includes from north to south significant regions with
distinctive characters--northern Sudan, western Sudan, the central
clay plains, eastern Sudan, the southern clay plains, and the Jabal
Hadid, or Ironstone Plateau, and southern hill masses .
Data as of June 1991
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 dunes drifting over the landscape.
There is virtually no rainfall in these deserts, and in the Nubian
Desert there are no oases. 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 nomads, caravans, 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 and 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. Western Darfur
stands in stark 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.,
than does the north. 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. 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
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 , the land between the Blue Nile and the White
Nile (literally in Arabic "peninsula") where the great Gezira Scheme
(also seen as 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 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. 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, and Shambe.
Second, As 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 as an obstacle to navigation that a passage was
not discovered until the midnineteenth 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
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 the watershed are the gallery forests,
the beginnings of the tropical rain forests that extend far into
Zaire. 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, Didinga, and Dongotona--which rise to more than 3,000 meters.
These mountains form a stark contrast to the great plains to the
north that dominate Sudan's geography.
Data as of June 1991
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 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,
sesame, peanuts, and (in the area around the Nuba Mountains) cotton.
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 millet, also occurs. Peanuts and
sesame are grown as cash crops. 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.
The laterite 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
Data as of June 1991
Except for a small area in northeastern Sudan where wadis discharge
the sporadic runoff into the Red Sea or rivers from Ethiopia 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 (Al Bahr al Azraq) and the White Nile (Al Bahr al Abyad).
The longest river in the world, the Nile flows for 6,737 kilometers
from its farthest headwaters in central Africa to the Mediterranean.
The importance of the Nile has been recognized since biblical times;
for centuries the river has been a lifeline for Sudan.
The Blue Nile flows out of the Ethiopian highlands to meet the
White Nile at Khartoum. The Blue Nile is the smaller of the two;
its flow usually accounts for only one-sixth of the total. 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. Several
dams have been constructed to regulate the river's flow--the Roseires
Dam (Ar Rusayris), about 100 kilometers from the Ethiopian border;
the Meina al Mak Dam at Sinjah; and the largest, the forty-meter-high
Sennar Dam constructed in 1925 at Sannar. 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. For the remainder of the year, their flow
is reduced to pools in their sandy riverbeds.
The White Nile flows north from central Africa, draining Lake Victoria
and the highland regions of Uganda, Rwanda, and Burundi. At Bor,
the great swamp of the Nile, As Sudd begins. The river has no well-defined
channel here; the water flows slowly through a labyrinth of small
spillways and lakes choked with papyrus and reeds. Much water is
lost to evaporation. To provide for water transportation through
this region and to speed the river's flow so that less water evaporates,
Sudan, with French help, began building the Jonglei Canal (also
seen as Junqali Canal) from Bor to a point just upstream from Malakal.
However, construction was suspended in 1984 because of security
problems caused by the civil war in the south.
South of Khartoum, the British built the Jabal al Auliya 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. Much water from
the reservoir has been diverted for irrigation projects in central
Sudan, however, or it merely evaporates, so the overall flow released
downstream is not great.
The White Nile has several substantial tributaries that drain southern
Sudan. In the southwest, the Bahr al Ghazal drains a basin larger
in area than France. Although the drainage area is extensive, evaporation
takes most of the water from the slowmoving streams in this region,
and the discharge of the Bahr al Ghazal into the White Nile is minimal.
In southeast Sudan, the Sobat River drains an area of western Ethiopia
and the hills near the Sudan-Uganda border. The Sobat's discharge
is considerable; at its confluence with the White Nile just south
of Malakal, the Sobat accounts for half the White Nile's water.
Above Khartoum, the Nile flows through desert in a large Sshaped
pattern to empty into Lake Nasser behind the Aswan High Dam in Egypt.
The river flows slowly above Khartoum, dropping little in elevation
although five cataracts hinder river transport at times of low water.
The Atbarah River, flowing out of Ethiopia, is the only tributary
north of Khartoum, and its waters reach the Nile for only the six
months between July and December. During the rest of the year, the
Atbarah's bed is dry, except for a few pools and ponds.
Data as of June 1991
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 or moist southwesterly winds from the
Congo River basin.
From January to March, the country is under the influence of the
dry northeasterlies. 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 southwesterlies 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 Abu 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 northeasterlies begin
to strengthen and to push south and by the end of December they
cover the entire country. Yambio, close to the border with Zaire,
has a nine-month rainy season (April-December) and receives an average
of 1,142 millimeters of rain each year; Khartoum has a three-month
rainy season (JulySeptember ) with an annual average rainfall of
161 millimeters; Atbarah receives showers in August that produce
an annual average of only 74 millimeters.
In some years, the arrival of the southwesterlies 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 southwesterlies 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 and temperatures can reach 48° C.
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 in January and have dropped as low as 6° C after the passing
of a cool front in winter.
The haboob, 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
Data as of June 1991