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Geography of Ethiopia

Ethiopia is located in the Horn of Africa and is bordered on the north and northeast by Eritrea, on the east by Djibouti and Somalia, on the south by Kenya, and on the west and southwest by Sudan. The country has a high central plateau that varies from 1,800 to 3,000 meters (6,000-10,000 feet) above sea level, with some mountains reaching 4,620 meters (15,158 feet). Elevation is generally highest just before the point of descent to the Great Rift Valley, which splits the plateau diagonally. A number of rivers cross the plateau--notably the Blue Nile rising from Lake Tana. The plateau gradually slopes to the lowlands of the Sudan on the west and the Somali-inhabited plains to the southeast.

The climate is temperate on the plateau and hot in the lowlands. At Addis Ababa, which ranges from 2,200 to 2,600 meters (7,000-8,500 feet), maximum temperature is 26C (80°F) and minimum 4C (40°F). The weather is usually sunny and dry with the short (belg) rains occurring February-April and the big (meher) rains beginning in mid-June and ending in mid-September.

Location: Eastern Africa, west of Somalia

Geographic coordinates: 8 00 N, 38 00 E

Map references: Africa

Area:
total: 1,127,127 sq km
land: 1,119,683 sq km
water: 7,444 sq km

Area - comparative: slightly less than twice the size of Texas

Land boundaries:
total: 5,311 km
border countries: Djibouti 337 km, Eritrea 912 km, Kenya 830 km, Somalia 1,626 km, Sudan 1,606 km

Coastline: 0 km (landlocked)

Maritime claims: none (landlocked)

Climate: tropical monsoon with wide topographic-induced variation

Terrain: high plateau with central mountain range divided by Great Rift Valley

Elevation extremes:
lowest point: Denakil -125 m
highest point: Ras Dashen Terara 4,620 m

Natural resources: small reserves of gold, platinum, copper, potash, natural gas, hydropower

Land use:
arable land: 12%
permanent crops: 1%
permanent pastures: 40%
forests and woodland: 25%
other: 22% (1993 est.)

Irrigated land: 1,900 sq km (1993 est.)

Natural hazards: geologically active Great Rift Valley susceptible to earthquakes, volcanic eruptions; frequent droughts

Environment - current issues: deforestation; overgrazing; soil erosion; desertification

Environment - international agreements:
party to: Biodiversity, Climate Change, Desertification, Endangered Species, Ozone Layer Protection
signed, but not ratified: Environmental Modification, Law of the Sea, Nuclear Test Ban

Geography - note: landlocked - entire coastline along the Red Sea was lost with the de jure independence of Eritrea on 24 May 1993


Text from 1911 encyclopedia - please edit as needed.

(1) Physical Features.-- Between the valley of the Upper Nile and the low lands which skirt the south-western shores of the Red Sea and the Gulf of Aden is a region of elevated plateaus from which rise various mountain ranges. These tablelands and mountains constitute Ethiopia, Shoa, Kaffa and Galla land. On nearly every side the walls of the plateaus rise with considerable abruptness from the plains, constituting outer mountain chains. The Ethiopian highlands are thus a clearly marked orographic division. From Ras Kasar (18 deg. N.) to Annesley Bay (15 deg. N.) the eastern wall of the plateau runs parallel to the Red Sea. It then turns due S. and follows closely the line of 40 deg. E. for some 400 miles About 9 deg. N. there is a break in the wall, through which the river. Hawash flows eastward. The main range at this point trends S.W., while south of the Hawash valley, which is some 3000 ft. below the level of the mountains, another massif rises in a direct line south. This second range sends a chain (the Harrar hills) eastward to the Gulf of Aden. The two chief eastern ranges maintain a parallel course S. by W., with a broad upland valley between---in which valley are a series of lakes---to about 3 deg. N., the outer (eastern) spurs of the plateau still keeping along the line of 40 deg. E. The southern escarpment of the plateau is highly irregular, but has a general direction N.W. and S.E. from 6 deg. N. to 3 deg. N. It overlooks the depression in which is Lake Rudolf and---east of that lake--southern Somaliland. The western wall of the plateau from 6 deg. N. to 11 deg. N. is well marked and precipitous. North of 11 deg. N. the hills turn more to the east and fall more gradually to the plains at their base. On its northern face also the plateau falls in terraces to the level of the eastern Sudan. The eastern escarpment is the best defined of these outer ranges. It has a mean height of from 7000 to 8000 ft., and in many places rises almost perpendicularly from the plain. Narrow and deep clefts, through which descend mountain torrents to lose themselves in the sandy soil of the coast land, afford means of reaching the plateau, or the easier route through the Hawash valley may be chosen. On surmounting this rocky barrier the traveller finds that the encircling rampart rises little above the normal level of the plateau.

(2) The aspect of the highlands is most impressive. The northern portion, lying mainly between 10 deg. and 15 deg. N., consists of a huge mass of Archaean rocks with a mean height of from 7000 to 7500 ft. above the sea, and is fl00ded in a deep central depression by the waters of Lake Tsana. Above the plateau rise several irregular and generally ill-defined mountain ranges which attain altitudes of from 12,000 to over 15,000 ft. Many of the mountains are of weird and fantastic shape. Characteristic of the country are the enormous fissures which divide it, formed in the course of ages by the erosive action of water. They are in fact the valleys of the rivers which, rising on the uplands or mountain sides, have cut their way to the surrounding lowlands. Some of the valleys are of considerable width; in other cases the opposite walls of the gorges are but two or three hundred yards apart, and fall almost vertically thousands of feet, representing an erosion of hard rock of many millions of cubic feet. One result of the action of the water has been the formation of numerous isolated flat-topped hills or small plateaus, known as ambas, with nearly perpendicular sides. The highest peaks are found in the Simen (or Semien) and Gojam ranges. The Simen Mountains he N.E. of Lake Tsana and culminate in the snow-covered peak of Daschan (Dajan), which has an altitude of 15,160 ft. A few miles east and north respectively of Dajan are Mounts Biuat and Abba Jared, whose summits are a few feet only below that of Dajan. In the Chok Mountains in Gojam Agsias Fatra attains a height of 13,600 ft.

Parallel with the eastern escarpment are the heights of Baila (12,500 ft.), Abuna Josef (13,780 ft.), and Kollo (14,100 ft.), the last-named being S.W. of Magdala. The valley between these hills and the eastern escarpment is one of the longest and most profound chasms in Ethiopia. Between Lake Tsana and the eastern hills are Mounts Guna (13,800 ft.) and Uara Sahia (13,000 ft.). The figures given are, however, approximate only. The southern portion of the highlands---the 10 deg. N. roughly marks the division between north and south---has more open tableland than the northern portion and fewer lofty peaks. Though there are a few heights between 10,000 and 12,000 ft., the majority do not exceed 8000 ft. But the general character of the southern regions is the same as in the north---a much-broken hilly plateau.

Most of the Ethiopian uplands have a decided slope to the north-west, so that nearly all the large rivers find their way in that direction to the Nile. Such are the Takazze in the north, the Abai in the centre, and the Sobat in the south, and through these three arteries is discharged about four-fifths of the entire drainage. The rest is carried off, almost due north by the Khor Baraka, which occasionally reaches the Red Sea south of Suakin; by the Hawash, which runs out in the saline lacustrine district near the head of Taiura Bay; by the Webi Shebeli (Wabi Shebeyli) and Juba, which flow S.E. through Somaliland, though the Shebeli fails to reach the Indian Ocean; and by the Omo. the main feeder of the closed basin of Lake Rudolf.

The Takazze, which is the true upper course of the Atbara, has its head-waters in the central tableland; and falls from about 7000 to 2500 ft. in the tremendous crevasse through which it sweeps round west, north and west again down to the western terraces, where it passes from Ethiopian to Sudan territory. During the rains the Takazze (i.e. the "Terrible") rises some 18 ft. above its normal level, and at this time forms an impassable barrier between the northern and central provinces. In its lower course the river is known by the Arab name Setit. The Setit is joined (14 deg. 10' N., 36 deg. E.) by the Atbara, a river formed by several streams which rise in the mountains W. and N.W. of Lake Tsana. The Gash or Mareb is the most northerly of the Ethiopian rivers which flow towards the Nile valley. Its head-waters rise on the landward side of the eastern escarpment within 50 miles of Annesley Bay on the Red Sea. It reaches the Sudan plains near Kassala, beyond which place its waters are dissipated in the sandy soil. The Mareb is dry for a great part of the year, but like the Takazze is subject to sudden freshets during the rains. Only the left bank of the upper course of the river is in Ethiopian territory, the Mareb here forming the boundary between Eritrea and Ethiopia.

(3) The Abai---that is, the upper course of the Blue Nile--has its source near Mount Denguiza in the Goiam highlands (about 11 deg. N. and 37 deg. E.), and first flows for 70 miles nearly due north to the south side of Lake Tsana. Tsana (q.v.), which stands from 2500 to 3000 ft. below the normal level of the plateau, has somewhat the aspect of a flooded crater. It has an area of about 1100 sq. m., and a depth in some parts of 250 ft. At the south-east corner the rim of the crater is, as it were. breached by a deep crevasse through which the Abai escapes, and here dovelb. ps a great semicircular bend like that of the Takazzo, but in the reverse direction---east, south and north-west---down to the plains of Sennar, where it takes the name of Bahr-el-Azrak or Blue Nile. The Abai has many tributaries. Of these the Bashilo rises near Magdala and drains eastern Amhara; the Jamma rises near Ankober and drains northern Shoa; the Muger rises near Adis Ababa and drains south-western Shoa; the Didessa, the largest of the Abai's affluents, rises in the Kaffa hills and has a generally S. to N. course; the Yabus runs near the western edge of the plateau escarpment. All these are perennial rivers. The right-hand tributaries, rising mostly on the western sides of the plateau, have steep slopes and are generally torrential in character. The Bolassa, however, is perennial, and the Rahad and Dinder are important rivers in flood-time.

In the mountains and plateaus of Kaffa and Galla in the south-west of Ethiopia rise the Baro, Gelo, Akobo and other of the chief affluents of the Sobat tributary of the Nile. The Akobo, in about 7 deg. 50' N. and 33 deg. E., joins the Pibor, which in about 8 1/2 deg. N. and 33 deg. 20' E. unites with the Baro, the river below the confluence taking the name of Sobat. These rivers descend from the mountains in great falls, and like the other Ethiopian streams are unnavigable in their upper courses. The Baro on reaching the plain becomes, however, a navigable stream affording an open waterway to the Nile. The Baro, Pibor and Akobo form for 250 miles the W. and S.W. frontiers of Ethiopia (see NILE, SOBAT and SUDAN.)

The chief river of Ethiopia flowing east is the Hawash (Awash, Awasi), which rises in the Shoan uplands and makes a semicircular bend first S.E. and then N.E. It reaches the Afar (Danakil) lowlands through a broad breach in the eastern escarpment of the plateau, beyond which it is joined on its left bank by its chief affluent, the Germama (Kasam), and then trends round in the direction of Tajura Bay. Here the Hawash is a copious stream nearly 200 ft. wide and 4 ft. deep, even in the dry season, and during the floods rising 50 or 60 ft. above low-water mark, thus inundating the plains for many miles along both its banks. Yet it fails to reach the coast, and after . a winding course of about 500 miles passes (in its lower reaches) through a series of badds (lagoons) to Lake Aussa, some 60 or 70 miles from the head.of Tajura Bay. In this lake the river is lost. This remarkable phenomenon is explained by the position of Aussa in the centre of a saline lacustrine depression several hundred feet below sea-level. While most of the other lagoons are highly saline, with thick incrustations of salt round their margins, Aussa remains fresh throughout the year, owing to the great body of water discharged into it by the Hawash.

Another lacustrine region extends from the Shoa heights south-west to the Samburu (Lake Rudolf) depression. In this chain of lovely upland lakes, some fresh, some brackish, some completely closed, others connected by short channels, the chief links in their order from north to south are:---Zwai, communicating southwards with Hara and Lamina, all in the Arusi Galla territory; then Abai with an outlet to a smaller tarn in the romantic Baroda and Gamo districts, skirted on the west sides by grassy slopes and wooded ranges from 6000 to nearly 9000 ft. high; lastly, in the Asille country, Lake Stefanie, the Chuwaha of the natives, completely closed and falling to a level of about 1800 ft. above the sea. To the same system obviously belongs the neighbouring Lake Rudolf (q.v.), which is larger than all the rest put together. This lake receives at its northern end the waters of the ()mo, which rises in the Shoa highlands and is a perennial river with many affluents. In its course of some 370 miles it has a total fall of about 6000 ft. (from 7600 at its source to 1600 at lake-level), and is consequently a very rapid stream, being broken by the Kokobi and other falls, and navigable only for a short distance above its mouth. The chief rivers of Somaliland (q.v.), the Webi Shebeli and the Juba (q.v.), have their rise on the south-eastenn slopes of the Ethiopian escarpment, and the greater part of their course is through territory belonging to Ethiopia. There are numerous hot springs in Ethiopia, and earthquakes, though of no great severity, are not uncommon.

(4) Geology.----The East African tableland is continued into Ethiopia. Since the visit of W. T. Blanford in 1870 the geology has received little attention from travellers. The following formations are represented:--

 
                    Sedimentary and Metamorphic.
 Recent.                        Coral, alluvium, sand.
 Tertiary.                      (?) Limestones of Harrar.
 Jurassic.                      Antalo Limestones.
 Triassic (?).                  Adigrat Sandstones.
 Archaean.                      Gneisses, schists, slaty rocks.
 
                            Igneous.
 Recent.                        Aden Volcanic Series.
 Tertiary, Cretaceous (?).      Magdala group.
 Jurassic.                      Ashangi group.
 

Archaean.--The metamorphic rocks compose the main mass of the tableland, and are exposed in every deep valley in Tigre and along the valley of the Blue Nile. Mica schists form the prevalent rocks. Hornblende schist also occur and a compact felspathic rock in the Suris defile. The foliae of the schists strike north and south.

Triassic (?).---In the region of Adigrat the metamorphic rocks are invariably overlain by white and brown sandstones, unfossiliferous, and attaining a maximum thickness of 1000 feet. They are overlain by the fossiliferous limestones of the Antalo group. Around Chelga and Adigrat coal-bearing beds occur, which Blanford suggests may be of the same age as the coal-bearing strata of India. The Adigrat Sandstone possibly represents some portion of the Karroo formation of South Africa.

Jurassic.---The fossiliferous limestones of Antalo are generally horizontal, but are in places much disturbed when interstratified with trap rocks. The fossils are all characteristic Oolite forms and include species of Hemicidaris, Pholadomya, Ceromya, Trigonia and Alaria.

Igneous Rocks.---Above a height of 8000 ft. the country consists of bedded traps belonging to two distinct and unconformable groups. The lower (Ashangi group) consists of basalts and dolerites often amygdaloidal. Their relation to the Antalo limestones is uncertain, but Blanford considers them to be not later in age than the Oolite. The upper (Magdala group) contains much trachytic rock of considerable thickness, lying perfectly horizontally, and giving rise to a series of terraced ridges characteristic of central Ethiopia. They are interbedded with unfossiliferous sandstones and shales. Of more recent date (probably Tertiary) are some igneous rocks, rich in alkalis, occurring in certain localities in southern Ethiopia. Of still more recent date are the basalts and ashes west of Massawa and around Annesley Bay and known as the Aden Volcanic Series. With regard to the older igneous rocks, the enormous amount they have suffered from denudation is a prominent feature. They have been worn into deep and narrow ravines, sometimes to a depth of 3000 to 4000 ft.

(5) Climate.---The climate of Ethiopia and its dependent territories varies greatly. Somaliland and the Danakil lowlands have a hot, dry climate producing semi-desert conditions; the country in the lower basin of the Sobat is hot, swampy and malarious. But over the greater part of Ethiopia as well as the Galla highlands the climate is very healthy and temperate. The country lies wholly within the tropics, but its nearness to the equator is counterbalanced by the elevation of the land. In the deep valleys of the Takazze and Abai, and generally in places below 4000 ft., the conditions are tropical and fevers are prevalent. On the uplands, however, the air is cool and bracing in summer, and in winter very bleak. The mean range of temperature is between 60 deg. and 80 deg. F. On the higher mountains the climate is Alpine in character. The atmosphere on the plateaus is exceedingly clear, so that objects are easily recognizable at great distances. In addition to the variation in climate dependent on elevation, the year may be divided into three seasons. Winter, or the cold season, lasts from October to February, and is followed by a dry hot period, which about the middle of June gives place to the rainy season. The rain is heaviest in the Takazze basin in July and August. In the more southern districts of Gojam and Wallega heavy rains continue till the middle of September, and occasionally October is a wet month. There are also spring and winter rains; indeed rain often falls in every month of the year. But the rainy season proper, caused by the south-west monsoon, lasts from June to mid-September, and commencing in the north moves southward. In the region of the Sobat sources the rains begin earlier and last longer. The rainfall varies from about 30 in. a year in Tigre and Amhara to over 40 in. in parts of Galla land. The rainy season is of great importance not only to Ethiopia but to the countries of the Nile valley, as the prosperity of the eastern Sudan and Egypt is largely dependent upon the rainfall. A season of light rain may be sufficient for the needs of Ethiopia, but there is little surplus water to find its way to the Nile; and a shortness of rain means a low Nile, as practically all the flood water of that river is derived from the Ethiopian tributaries (see NILE.)

(6) Flora and Fauna.--As in a day's journey the traveller may pass from tropical to almost Alpine conditions of climate, so great also is the range of the flora and fauna. In the valleys and lowlands the vegetation is dense, but the general appearance of the plateaus is of a comparatively bare country with trees and bushes thinly scattered over it. The glens and ravines on the hillside are often thickly wooded, and offer a delightful contrast to the open downs. These conditions are particularly characteristic of the northern regions; in the south the vegetation on the uplands is more luxuriant. Among the many varieties of trees and plants found are the date palm, mimosa, wild olive, giant sycamores, junipers[?] and laurels[?], the myrrh and other gum trees (gnarled and stunted, these flourish most on the eastern foothills), a magnificent pine (the Natal yellow pine, which resists the attacks of the white ant), the fig, orange, lime, pomegranate, peach, apricot, banana, and other fruit trees; the grape vine (rare), blackberry, and raspberry[?]; the cotton and indigo Plants, and occasionally the sugar cane. There are in the south large forests of valuable timber trees; and the coffee plant is indigenous in the Kaffa[?] country, whence it takes its name. Many kinds of grasses and flowers abound. Large areas are covered by the kussa[?], a hardy member of the rose family, which grows from 8 to 10 ft. high and has abundant pendent red blossoms. The flowers and the leaves of this plant are highly prized for medicinal purposes. The fruit of the hurarina[?], a tree found almost exclusively in Shoa, yields a black grain highly esteemed as a spice. On the tableland a great variety of grains and vegetables are cultivated. A fibrous plant, known as the sanseviera[?], grows in a wild state in the semi-desert[?] regions of the north and south-east.

In addition to the domestic animals enumerated below (sec. 8) the fauna is very varied. Elephant and rhinoceros are numerous in certain low-lying districts, especially in the Sobat valley. The Ethiopian rhinoceros has two horns and its skin has no folds. The hippopotamus and crocodile inhabit the larger rivers flowing west, but are not found in the Hawash, in which, however, otters of large size are plentiful. Lions abound in the low countries and in Somaliland. In central Ethiopia the lion is no longer found except occasionally in the river valleys. Leopards, both spotted and black, are numerous and often of great size; hyenas are found everywhere and are hardy and fierce; the lynx, wolf, wild dog and jackal are also common. Boars and badgers are more rarely seen. The giraffe is found in the western districts, the zebra and wild ass frequent the lower plateaus and the rocky hills of the north. There are large herds of buffalo and antelope, and gazelles of many varieties and in great numbers are met with in most parts of the country. Among the varieties are the greater and lesser kudu[?] (both rather rare); the duiker, gemsbuck[?], hartebeest[?], gerenuk[?] (the most common--it has long thin legs and a camel-like neck); klipspringer[?], found on the high plateaus as well as in the lower districts; and the dik-dik[?], the smallest of the antelopes, its weight rarely exceeding 10 lb. , common in the low countries and the foothills. The civet is found in many parts of Ethiopia, but chiefly in the Galla[?] regions. Squirrels and hares are numerous, as are several kinds of monkeys, notably the guereza[?], gelada[?], guenon[?] and dog-faced baboon. They range from the tropical lowlands to heights of 10,000 ft.

Birds are very numerous, and many of them remarkable for the beauty of their plumage. Great numbers of eagles, vultures, hawks, bustards and other birds of prey are met with; and partridges, duck, teal, guinea-fowl[?], sand-grouse[?], curlews, woodcock, snipe, pigeons, thrushes and swallows are very plentiful. A fine variety of ostrich is commonly found. Among the birds prized for their plumage are the marabout, crane, heron, blacks bird[?], parrot, jay and hummingbirds of extraordinary brilliance,

Among insects the most numerous and useful is the bee, honey everywhere constituting an important part of the food of the inhabitants. Of an opposite class is the locust. There are thousands of varieties of butterflies and other insects. Snakes are not numerous, but several species are poisonous.

See also : Ethiopia



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