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 Sarh, Chad
Abeche, Chad
Moundou, Chad
Ndjamena, Chad
Bokoro, Chad
Bol-Berim, Chad
Am-Timan, Chad
Pala, Chad
Faya, Chad
Location: Central Africa, south of Libya
Geographic coordinates: 15 00 N, 19 00 E
Map references: Africa
Area:
total: 1.284 million sq km
land: 1,259,200 sq km
water: 24,800 sq km
Area - comparative: slightly more than three times the size
of California
Land boundaries:
total: 5,968 km
border countries: Cameroon 1,094 km, Central African Republic
1,197 km, Libya 1,055 km, Niger 1,175 km, Nigeria 87 km, Sudan 1,360
km
Coastline: 0 km (landlocked)
Maritime claims: none (landlocked)
Climate: tropical in south, desert in north
Terrain: broad, arid plains in center, desert in north,
mountains in northwest, lowlands in south
Elevation extremes:
lowest point: Djourab Depression 160 m
highest point: Emi Koussi 3,415 m
Natural resources: petroleum (unexploited but exploration
under way), uranium, natron, kaolin, fish (Lake Chad)
Land use:
arable land: 3%
permanent crops: 0%
permanent pastures: 36%
forests and woodland: 26%
other: 35% (1993 est.)
Irrigated land: 140 sq km (1993 est.)
Natural hazards: hot, dry, dusty harmattan winds occur in
north; periodic droughts; locust plagues
Environment - current issues: inadequate supplies of potable
water; improper waste disposal in rural areas contributes to soil
and water pollution; desertification
Environment - international agreements:
party to: Biodiversity, Climate Change, Desertification,
Endangered Species, Nuclear Test Ban, Ozone Layer Protection, Wetlands
signed, but not ratified: Law of the Sea, Marine Dumping
Geography - note: landlocked; Lake Chad is the most significant
water body in the Sahel
Chad
GEOGRAPHY
Size: Approximately 1,284,000 square kilometers.
Topography: Northern third desert, with mountains
in north and plateaus in northeast; central third broad, arid savanna
with Lake Chad in west, massif in center, and highlands in east;
southern third wooded and humid lowlands, intersected by rivers.
Climate: Northern Saharan zone generally hot and
dry; central sahelian zone mostly dry with rainy season
from June to early September; southern soudanian zone tropical
with rainy season lasting from April to October.
Data as of December 1988
Chad
PHYSICAL SETTING
Located in north-central Africa, Chad stretches for about 1,800
kilometers from its northernmost point to its southern boundary.
Except in the far northwest and south, where its borders converge,
Chad's average width is about 800 kilometers. Its area of 1,284,000
square kilometers is roughly equal to the combined areas of Idaho,
Wyoming, Utah, Nevada, and Arizona. Chad's neighbors include Libya
to the north, Niger and Nigeria to the west, Sudan to the east,
Central African Republic to the south, and Cameroon to the southwest.
Chad exhibits two striking geographical characteristics. First,
the country is landlocked. N'Djamena, the capital, is located more
than 1,100 kilometers northeast of the Atlantic Ocean; Abéché, a
major city in the east, lies 2,650 kilometers from the Red Sea;
and Faya Largeau, a much smaller but strategically important center
in the north, is in the middle of the Sahara Desert, 1,550 kilometers
from the Mediterranean Sea. These vast distances from the sea have
had a profound impact on Chad's historical and contemporary development.
The second noteworthy characteristic is that the country borders
on very different parts of the African continent: North Africa,
with its Islamic culture and economic orientation toward the Mediterranean
Basin; West Africa, with its diverse religions and cultures and
its history of highly developed states and regional economies; Northeast
Africa, oriented toward the Nile Valley and Red Sea region; and
Central or Equatorial Africa, some of whose people have retained
classical African religions while others have adopted Christianity,
and whose economies were part of the great Zaire River system. Although
much of Chad's distinctiveness comes from this diversity of influences,
since independence the diversity has also been an obstacle to the
creation of a national identity.
Data as of December 1988
Chad
The Land
Although Chadian society is economically, socially, and culturally
fragmented, the country's geography is unified by the Lake Chad
Basin . Once a huge inland sea (the Pale-Chadian Sea) whose only
remnant is shallow Lake Chad, this vast depression extends west
into Nigeria and Niger. The larger, northern portion of the basin
is bounded within Chad by the Tibesti Mountains in the northwest,
the Ennedi Plateau in the northeast, the Ouaddaï Highlands in the
east along the border with Sudan, the Guéra Massif in central Chad,
and the Mandara Mountains along Chad's southwestern border with
Cameroon. The smaller, southern part of the basin falls almost exclusively
in Chad. It is delimited in the north by the Guéra Massif, in the
south by highlands 250 kilometers south of the border with Central
African Republic, and in the southwest by the Mandara Mountains.
Lake Chad, located in the southwestern part of the basin at an
altitude of 282 meters, surprisingly does not mark the basin's lowest
point; instead, this is found in the Bodele and Djourab regions
in the north-central and northeastern parts of the country, respectively.
This oddity arises because the great stationary dunes (ergs)
of the Kanem region create a dam, preventing lake waters from flowing
to the basin's lowest point. At various times in the past, and as
late as the 1870s, the Bahr el Ghazal Depression, which extends
from the northeastern part of the lake to the Djourab, acted as
an overflow canal; since independence, climatic conditions have
made overflows impossible.
North and northeast of Lake Chad, the basin extends for more than
800 kilometers, passing through regions characterized by great rolling
dunes separated by very deep depressions. Although vegetation holds
the dunes in place in the Kanem region, farther north they are bare
and have a fluid, rippling character. From its low point in the
Djourab, the basin then rises to the plateaus and peaks of the Tibesti
Mountains in the north. The summit of this formation--as well as
the highest point in the Sahara Desert--is Emi Koussi, a dormant
volcano that reaches 3,414 meters above sea level. The basin's northeastern
limit is the Ennedi Plateau, whose limestone bed rises in steps
etched by erosion.
East of the lake, the basin rises gradually to the Ouaddaï Highlands,
which mark Chad's eastern border and also divide the Chad and Nile
watersheds. Southeast of Lake Chad, the regular contours of the
terrain are broken by the Guéra Massif, which divides the basin
into its northern and southern parts.
South of the lake lie the floodplains of the Chari and Logone rivers,
much of which are inundated during the rainy season. Farther south,
the basin floor slopes upward, forming a series of low sand and
clay plateaus, called koros, which eventually climb to
615 meters above sea level. South of the Chadian border, the koros
divide the Lake Chad Basin from the Ubangi-Zaire river system.
Data as of December 1988
Chad
Water Systems
Permanent streams do not exist in northern or central Chad. Following
infrequent rains in the Ennedi Plateau and Ouaddaï Highlands, water
may flow through depressions called enneris and wadis.
Often the result of flash floods, such streams usually dry out within
a few days as the remaining puddles seep into the sandy clay soil.
The most important of these streams is the Batha, which in the rainy
season carries water west from the Ouaddaï Highlands and the Guéra
Massif to Lake Fitri.
Chad's major rivers are the Chari and the Logone and their tributaries,
which flow from the southeast into Lake Chad. Both river systems
rise in the highlands of Central African Republic and Cameroon,
regions that receive more than 1,250 millimeters of rainfall annually.
Fed by rivers of Central African Republic, as well as by the Bahr
Salamat, Bahr Aouk, and Bahr Sara rivers of southeastern Chad, the
Chari River is about 1,200 kilometers long. From its origins near
the city of Sarh, the middle course of the Chari makes its way through
swampy terrain; the lower Chari is joined by the Logone River near
N'Djamena. The Chari's volume varies greatly, from 17 cubic meters
per second during the dry season to 340 cubic meters per second
during the wettest part of the year.
The Logone River is formed by tributaries flowing from Cameroon
and Central African Republic. Both shorter and smaller in volume
than the Chari, it flows northeast for 960 kilometers; its volume
ranges from five to eighty-five cubic meters per second. At N'Djamena
the Logone empties into the Chari, and the combined rivers flow
together for thirty kilometers through a large delta and into Lake
Chad. At the end of the rainy season in the fall, the river overflows
its banks and creates a huge floodplain in the delta.
The seventh largest lake in the world (and the fourth largest in
Africa), Lake Chad is located in the sahelian zone, a region
just south of the Sahara Desert. The Chari River contributes 95
percent of Lake Chad's water, an average annual volume of 40 billion
cubic meters, 95 percent of which is lost to evaporation. The size
of the lake is determined by rains in the southern highlands bordering
the basin and by temperatures in the Sahel. Fluctuations in both
cause the lake to change dramatically in size, from 9,800 square
kilometers in the dry season to 25,500 at the end of the rainy season.
Lake Chad also changes greatly in size from one year to another.
In 1870 its maximum area was 28,000 square kilometers. The measurement
dropped to 12,700 in 1908. In the 1940s and 1950s, the lake remained
small, but it grew again to 26,000 square kilometers in 1963. The
droughts of the late 1960s, early 1970s, and mid-1980s caused Lake
Chad to shrink once again, however. The only other lakes of importance
in Chad are Lake Fitri, in Batha Prefecture, and Lake Iro, in the
marshy southeast.
Data as of December 1988
Chad
Climate
The Lake Chad Basin embraces a great range of tropical climates
from north to south, although most of these climates tend to be
dry. Apart from the far north, most regions are characterized by
a cycle of alternating rainy and dry seasons. In any given year,
the duration of each season is determined largely by the positions
of two great air masses--a maritime mass over the Atlantic Ocean
to the southwest and a much drier continental mass. During the rainy
season, winds from the southwest push the moister maritime system
north over the African continent where it meets and slips under
the continental mass along a front called the "intertropical convergence
zone". At the height of the rainy season, the front may reach as
far as Kanem Prefecture. By the middle of the dry season, the intertropical
convergence zone moves south of Chad, taking the rain with it. This
weather system contributes to the formation of three major regions
of climate and vegetation.
Data as of December 1988
Chad
Saharan Region
The Saharan region covers roughly the northern third of the country,
including Borkou-Ennedi-Tibesti Prefecture along with the northern
parts of Kanem, Batha, and Biltine prefectures . Much of this area
receives only traces of rain during the entire year; at Faya Largeau,
for example, annual rainfall averages less than three centimeters.
Scattered small oases and occasional wells provide water for a few
date palms or small plots of millet and garden crops. In much of
the north, the average daily maximum temperature is about 32°
C during January, the coolest month of the year, and about 45°
C during May, the hottest month. On occasion, strong winds from
the northeast produce violent sandstorms. In northern Biltine Prefecture,
a region called the Mortcha plays a major role in animal husbandry.
Dry for nine months of the year, it receives 350 millimeters or
more of rain, mostly during July and August. A carpet of green springs
from the desert during this brief wet season, attracting herders
from throughout the region who come to pasture their cattle and
camels. Because very few wells and springs have water throughout
the year, the herders leave with the end of the rains, turning over
the land to the antelopes, gazelles, and ostriches that can survive
with little groundwater.
Data as of December 1988
Chad
Sahelian Region
The semiarid sahelian zone, or Sahel, forms a belt about
500 kilometers wide that runs from Lac and Chari-Baguirmi prefectures
eastward through Guéra, Ouaddaï, and northern Salamat prefectures
to the Sudanese frontier. The climate in this transition zone between
the desert and the southern soudanian zone is divided into
a rainy season (from June to early September) and a dry period (from
October to May). In the northern Sahel, thorny shrubs and acacia
trees grow wild, while date palms, cereals, and garden crops are
raised in scattered oases. Outside these settlements, nomads tend
their flocks during the rainy season, moving southward as forage
and surface water disappear with the onset of the dry part of the
year. The central Sahel is characterized by drought-resistant grasses
and small woods. Rainfall is more abundant there than in the Saharan
region. For example, N'Djamena records a maximum annual average
rainfall of 580 millimeters, while Ouaddaï Prefecture receives just
a bit less. During the hot season, in April and May, maximum temperatures
frequently rise above 40°C. In the southern part of the Sahel,
rainfall is sufficient to permit crop production on unirrigated
land, and millet and sorghum are grown . Agriculture is also common
in the marshlands east of Lake Chad and near swamps or wells. Many
farmers in the region combine subsistence agriculture with the raising
of cattle, sheep, goats, and poultry.
Data as of December 1988
Chad
Soudanian Region
The humid soudanian zone includes the southern prefectures
of Mayo-Kebbi, Tandjilé, Logone Occidental, Logone Oriental, Moyen-Chari,
and southern Salamat. Between April and October, the rainy season
brings between 750 and 1,250 millimeters of precipitation. Temperatures
are high throughout the year. Daytime readings in Moundou, the major
city in the southwest, range from 27°C in the middle of the
cool season in January to about 40°C in the hot months of March,
April, and May.
The soudanian region is predominantly savanna, or plains
covered with a mixture of tropical or subtropical grasses and woodlands.
The growth is lush during the rainy season but turns brown and dormant
during the five-month dry season between November and March. Over
a large part of the region, however, natural vegetation has yielded
to agriculture.
Data as of December 1988
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