1911 Encyclopædia Britannica/Zambezi

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ZAMBEZI, the fourth in size of the rivers of Africa, and the largest of those flowing eastwards to the Indian Ocean. Its length (taking all curves into consideration) is about 2200 m. The area of its basin, according to Dr Bludau, is 513,500 sq. m., or rather less than half that of the Nile. The main channel is clearly marked from beginning to end. The river takes its rise in 11° 21′ 3″ S., 24° 22′ E. The source lies in British territory in a depression of an undulating country 5000 ft. above the sea, covered with bracken and open forest. The water, like that of all the rivers of the neighbourhood, issues from a black marshy bog, and quickly collects into a well-defined stream. In the first hundred miles of its course the river is known as the Yambeshe—in sound almost identical with its name in its lower course, though intervening sections are known as Liambeshe, Liambai, &c. Eastward of the source the water-parting between the Congo and Zambezi basins is a well-marked belt of high ground, falling abruptly north and south, and running nearly east and west between 11° and 12° S. This distinctly cuts off the basin of the Luapula (the main branch of the upper Congo) from that of the Zambezi. In the neighbourhood of the source, however, the water-parting is not so clear, but the two river systems do not connect.

The Upper River.—The infant Zambezi, after pursuing a south-westerly course for about 150 m., turns more directly south and, soon after the 12° S. is crossed, is joined by a stream (coming from the north-west) whose source is near a marshy lake called Dilolo, 4600 ft. above sea-level in 11° 50′ S., 22° 10′ E. Lake Dilolo was at one time believed to communicate with the Kasai river, one of the great affluents of the Congo flowing north-west, but this is not the case. Dilolo belongs to the Zambezi system only, sending water to that river after heavy rain. The Zambezi as it flows southward receives on either side numerous small tributaries. A few miles above Kakengi (in 12° 24′ S.), the Zambezi, narrow, picturesque and tortuous, suddenly widens from 100 to 350 yds. Below Kakengi are a number of rapids ending (13° 7′ S.) in the Sapuma cataracts. At this point the river flows tumultuously through a rocky fissure.

The first of its large tributaries to enter the Zambezi is the Kabompo, a left-hand affluent. It joins the main stream in 14° 26′ S. A little lower down (in 14° 18′ S.) the Zambezi receives from the west the waters of a much larger stream than the Kabompo, namely, the Lungwebungu. (For details concerning these and the other chief tributaries of the Zambezi, see below.) The savannah forest, which has hitherto characterized the country, now gives place to a more open bush valley, studded with Borassus palms. Dense vegetation is confined to narrow strips of matted forest which skirt the first few hundred yards of the sources of the Zambezi and its tributaries during the first 100 m. or so. The land, from 5000 ft. at the source, falls gradually to 3600 ft. at Kakengia distance of 220 m. From this point until the Victoria Falls are reached—500 m.—the level of the Zambezi basin is very uniform, the fall being in this distance 600 ft. only. Twenty miles below the confluence of the Lungwebungu the country becomes flat, and in the rainy seasons is largely covered by floods. Some 50 m. farther down, the Luanginga, which with its tributaries drains a large area to the westward, joins the Zambezi. A few miles higher up on the cast the main stream is reinforced by the waters of the Luena. On the same (eastern) side a little below the junction of the Luanginga and the Zambezi stands Lialui, the capital of the Barotse (q.v.). The river, which for some distance has had a slight western as well as southern trend, now turns distinctly south-east. From the cast the Zambezi continues to receive numerous small streams, but on the west is without tributaries for 150 m., when the great river formerly misnamed the Chobe, but known to the natives as Kwando or Linyante, joins it (in 17° 47′ S.). Before this junction is effected, the Gonye Falls, the work of erosion (16° 40′ S.), offer an interruption to navigation, whilst below the falls are numerous rapids. The western bank of the Zambezi, which in this part of its course is very tortuous, is German territory from the most southern of these rapids—Katima Molilo (17° 28′ S.)—to the confluence of the Kwando, including the right or northern bank of the lower course of the last-named river; this narrow strip of land projecting from the main portion of German South-West Africa expressly to allow Germany access to the Zambezi.

Below the junction of the Kwando and the Zambezi the river bends almost due east. The stream has hitherto flowed, in the main, in a gentle steady current, the depth of water, owing to the breadth of the channel, not being great. But its character is about to change. As it flows eastward towards the border of the great central plateau of Africa it reaches a tremendous chasm in the floor of the earth, and thus the Victoria Falls (q.v.), the largest waterfalls in the world, are formed.

The Middle Zambezi.—The Victoria Falls are reached some 60 m. after the Kwando confluence is passed, and below them the river continues to flow due east for about 120 m. It then cuts its way throuch perpendicular walls of basalt from 60 to 100 ft. apart. This dismal canyon, named by Major St Hill Gibbons “The Devil's Gorge,” is 8 m. long. Towering over the rocks which form the banks of the river are precipitous hills, 700 to 800 ft. high. The river flows swiftly through the gorge, the current being continually interrupted by reefs. Beyond the gorge are a succession of rapids, ending with those called Molele, which is 146 m. below the Victoria Falls. In this distance the fall of the river is 800 ft. From the Devil's Gorge the Zambezi takes a decided trend north whilst still pursuing its general easterly course. For the next 700 m. until the Kebrabasa Rapids are reached, the river flows through well-defined and occasionally rocky banks. Besides the rapids already mentioned there are several others in the middle stretch of the river, forming impediments to navigation at low water. One of the most difficult passages is that of a grand gorge a little above the mouth of the Loangwa, in about 30° E., named by Major Gibbons Livingstone's Kariba, in distinction from a second Kariba ( = “gorge”) a little beyond the Kafukwe confluence. Between the two gorges the river is generally unobstructed, but at the western end of the second Kariba navigation is dangerous at low water. Exclusive of the Shiré (q.v.) the Loangwa and the Kafukwe (also called Kafue) just mentioned are the two largest left-hand tributaries of the Zambezi. The Kafukwe joins the main river in 15° 57′ S. in a quiet deep stream about 200 yds. wide. From this point the northward bend of the Zambezi is checked and the stream continues due east. At the confluence of the Loangwa (15° 37′ S.) it enters Portuguese territory, and from this point to the sea both banks of the river belong to that kingdom. At the Kebrabasa Rapids—800 m. below the Victoria Falls—the Zambezi is sharply deflected to the south, the river at this point breaking through the continental escarpment to reach the sea. The Kebrabasa Rapids, which extend about 45 m.—the road taking a detour of 70 m.—are absolutely unnavigable, and with them the middle stretch of the Zambezi as definitely ends as does the upper river at the Victoria Falls.

The Lower River.—The lower Zambezi—400 m. from Kebrabasa Rapids to the sea—presents no obstacles to navigation save the shallowness of the stream in many places in the dry season. This shallowness arises from the different character of the river basin. Instead of, as in the case of the middle Zambezi, flowing mainly through hilly country with well-defined banks, the river traverses a broad valley and spreads out over a large area. Only at one point, the Lupata Gorge, 200 m. from its mouth, is the river confined between high hills. Here it is scarcely 200 yds. wide. Elsewhere it is from 3 to 5 m. wide, flowing gently in many streams. The riverbed is sandy, the banks are low and reed-fringed. At places, however, and especially in the rainy season, the streams unite into one broad swift-flowing river. About 100 m. from the sea the Zambezi receives the drainage of Lake Nyasa through the river Shiré. On approaching the ocean, which it reaches in 18° 50′ S. the Zambezi splits up into a number of branches and forms a wide delta. Each of the four principal mouths—Milambe, Kongone, Luabo and Timbwe—is obstructed by a sand-bar. A more northerly branch, called the Chinde mouth, has a minimum depth at low water of 7 ft. at the entrance, and of 12 ft. farther in, and is the branch used for navigation. Sixty miles farther north is a river called the Qua-Qua or Quilimane, from the town founded by the Portuguese at its mouth. This stream, which is silting up, receives in the rainy season the overflow of the Zambezi.

The region drained by the Zambezi may be represented as a vast broken-edged plateau 3000 or 4000 ft. high, composed in the remote interior of metamorphic beds and fringed with the igneous rocks of the Victoria Falls. At Shupanga, on the lower Zambezi, thin strata of grey and yellow sandstones, with an occasional band of limestone, crop out on the bed of the river in the dry season, and these persist beyond Tete, where they are associated with extensive seams of coal. Coal is also found in the district just below the Victoria Falls. Gold-bearing rocks occur in several places.

Four Thousand Miles of Navigable Water.—As a highway into the interior of the continent the Zambezi, like all other large African rivers, in greater or less degree, suffers on account of the bar at its mouth, the shallowness of its stream, and the rapids and cataracts which interrupt its course. Nevertheless its importance to commerce is great, as the following recapitulation of its navigable stretches will show. (1) From the sea to the Kebrabasa Rapids, 400 m. (2) From Chikoa (above Kebrabasa) to within 140 m. of the Victoria Falls, 700 m. (3) From the rapids above the Victoria Falls to the Katima Molilo Rapids, 100 m. (4) Above the Gonye Falls to the Supuma cataract, 300 m. (5) Above the Supuma cataract, 120 m. Thus for 1620 m. of its course the Zambezi is navigable for steamers with a draught of from 18 to 28 in. Were the obstruction caused by the Kebrabasa Rapids removed, there would be a clear passage from the sea almost to the foot of the cataracts below the Victoria Falls. The difficulty at Kebrabasa might be removed either by the cutting of a side channel or the building of a dam to convert the gorge into a lake, to be connected with the river below by a lock and weir.

Several of the Zambezi affluents are also navigable for many miles. The Lungwebungu, which enters the upper river, is navigable for a long distance, thus supplying communication with the extreme north-west corner of the Zambezi basin. Parts at least of the Luena, Kafukwe, Loangwa and the Kwando tributaries are also capable of being navigated. The possibility of connecting the Kwando with the navigable waters of the Okavango, at the point where the overflow mentioned below takes place, has likewise been suggested. The Shiré is also navigable for a considerable distance. The sum of such navigable reaches within the Zambezi basin as exceed 100 m. is nearly 4000 m.

Tributaries.—The tributaries of the Zambezi are very numerous. The course of the more important streams is as follows: The Kabompo, which flows in from the east in about 14° 8′ S., rises not far from 11° 34′ S., 25° 17′ E. in the high land which forms the eastern watershed between the Zambezi and Congo systems. In 13½° S. it receives on the right bank a tributary, the Lunga, said to be more important than the upper Kabompo itself, and rising somewhat farther north. The Lungwebungu, which enters the Zambezi from the west in 14° 35′ S., is a strong, deep stream 200 yds. wide in its upper course, flowing in a valley bordered by undulations of white sand covered by thin forest, its floor forming at times an inundated plain 2 to 3 m. wide.

The Kwando, largest of the western affluents of the Zambezi, formerly known as the Chobe and frequently spoken of as the Linyante from the ruined capital of the Makololo, situated on its lower course, rises in about 12° 40′ S., 18° 50′ E., and flows in a generally straight course south-east to 17° 30′ S., at which point it makes a sudden bend to the south before flowing east to the Zambezi. In this eastward stretch the Kwando for some 70 m. flows through a vast reedy swamp or lake studded with alluvial islands. Apart from its head-streams, it receives most of its tributaries from the west, and at its most southern bend is joined by the Magwe'-kwana, which in time of flood receives some of the surplus water of the Okavango (see Ngami). This surplus water, received after most of the flood water of the Kwando has passed, raises the level of the lake and holds up the waters of the Kwando for some miles above it.

Of the streams which enter the upper Zambezi from the east, the largest, after the Kabompo, is the Luena, which rises in 16° S., 26° E., and flows first north-west, afterwards west-south-west, joining the main river a little north of 15° S. Others are the Njoko joining in 17° 8′ S., the Machili, which enters in about 25° E., the Lumbi, 16° 45′ S., and the Umgwezi, 17° 37′ S. The largest tributary of the middle Zambezi—the Kafukwe—rises" in about 11° 35′ S. at an elevation of 4400 ft. in thick forest country. The main head-stream, which flows first south-east, afterwards south-west, is joined in 14° 35′ S. by the Lunga or Luanga, an important right-bank tributary, the united stream then flowing first south, afterwards due east. The lower Kafukwe is a large navigable river until about 40 m. from its mouth, but it then descends from the plateau by a series of falls and cataracts, the drop being over 1000 ft. in 15 m., one very high fall occurring in a stupendous chasm. The next great tributary to the east is the Loangwa (also called Luangwa) which in its upper course runs parallel to the western shores of Lake Nyasa, having its source not far from the north-west corner of the lake. The main stream flows in a generally level valley, bounded by steep plateau escarpments, and is for the most part shallow and rapid, though fairly wide. In 14° 30′ S., however, it passes through narrow gorges with a speed of 8 or 9 m. an hour. In 15° 5′ S. it is joined by the Lunsefwa, which, with its tributary, the Lukosasi, drains a large extent of the western plateau, its basin being separated by the Mchinga mountains from that of the Loangwa. The Loangwa joins the Zambezi a little above the town of Zumbo. For some distance its lower course forms the frontier between Portuguese and British territory. From the south the middle Zambezi receives various rivers which water northern Matabele and Mashona lands—namely, the Shangani, Sanyati, and Hanyani, besides minor streams. The Mazoe, which also rises in Mashonaland, joins the Zambezi below the Kebrabasa Rapids.

Exploration of the River.—The Zambezi region was known to the medieval geographers as the empire of Monomotapa and the course of the river, as well as the position of Lakes Ngami and Nyasa, was filled in with a rude approximation to accuracy in the earlier maps. These were probably constructed from Arab information. The first European to visit the upper Zambezi was David Livingstone in his exploration from Bechuanaland between 1851 and 1853. Two or three years later he descended the Zambezi to its mouth and in the course of this journey discovered the Victoria Falls. During 1858-60, accompanied by Dr (afterwards Sir) John Kirk, Livingstone ascended the river by the Kongone mouth as far as the Falls, besides tracing the course of its tributary the Shiré and discovering Lake Nyasa. For the next thirty-five years practically no additions were made to our knowledge of the river system. In 1889 the entrance of vessels from the sea was much facilitated by the discovery by Mr D. J. Rankin of the Chinde channel north of the main mouths of the river. Major A. St Hill Gibbons and his assistants, during two expeditions, in 1895-96 and 1898-1900, ably continued the work of exploration begun by Livingstone in the upper basin and central course of the river. Of non-British travellers Major Serpa Pinto examined some of the western tributaries of the river and made measurements of the Victoria Falls (1878). Steamers had been used on the lower river—the “Ma-Robert” and the “Pioneer”—by the Livingstone expedition of 1858-61, but the utilization of the Zambezi as a commercial highway was inconsiderable until after the discovery of the Chinde mouth. The first steamer placed on the river above the Kebrabasa Rapids was the “Constance” launched by the Gibbons expedition at Chikoa in September 1898. She steamed to beyond the Guay confluence, and being ultimately sold to a commercial company, was used to carry goods on the middle Zambezi. The first steamer placed on the river above the Victoria Falls was the “Livingstone,” launched in August 1902.

See David and Charles Livingstone, Narrative of an Expedition to the Zambesi and its Tributaries (1865); A. de Serpa Pinto, How I Crossed Africa (1881); D. J. Rankin in Proc. R. G. S. (March, 1890); A. Sharpe, ibid. (December, 1890); H. S. Bivar, “Curso medio do Zambeze,” B. S. G. Lisboa, vol. xxiv. (1906); G. W. Lamplugh in Geo. Jnl., vol. xxxi. (1908); F. Coillard, On the Threshold of Central Africa (London, 1897), and A. St H. Gibbons, Africa from South to North through Marotseland (2 vols., London, 1904), which gives the results of a detailed examination of the upper Zambezi valley (with map). The last-named author has kindly revised the account given above.  (F. R. C.)