Juba, or Jub, a river of East Africa, exceeding 1000 m. in length, rising on the S.E. border of the Abyssinian highlands and flowing S. across the Galla and Somali countries to the sea. It is formed by the junction of three streams, all having their source in the mountain range N.E. of Lake Rudolf which is the water-parting between the Nile basin and the rivers flowing to the Indian Ocean.
Of the three headstreams, the Web, the Ganale and the Daua, the Ganale (or Ganana) is the central river and the true upper course of the Juba. It has two chief branches, the Black and the Great Ganale. The last-named, the most remote source of the river, rises in 7° 30′ N., 38° E. at an altitude of about 7500 ft., the crest of the mountains reaching another 2500 ft. In its upper course it flows over a rocky bed with a swift current and many rapids. The banks are clothed with dense jungle and the hills beyond with thorn-bush. Lower down the river has formed a narrow valley, 1500 to 2000 ft. below the general level of the country. Leaving the higher mountains in about 5° 15′ N., 40° E., the Ganale enters a large slightly undulating grass plain which extends south of the valley of the Daua and occupies all the country eastward to the junction of the two rivers. In this plain the Ganale makes a semicircular sweep northward before resuming its general S.-E. course. East of 42° E. in 4° 12′ N. it is joined by the Web on the left or eastern bank, and about 10 m. lower down the Daua enters on the right bank.
The Web rises in the mountain chain a little S. and E. of the sources of the Ganale, and some 40 m. from its source passes, first, through a cañon 500 ft. deep, and then through a series of remarkable underground caves hollowed out of a quartz mountain and, with their arches and white columns, presenting the appearance of a pillared temple. The Daua (or Dawa) is formed by the mountain torrents which have their rise S. and W. of the Ganale and is of similar character to that river. It has few feeders and none of any size. The descent to the open country is somewhat abrupt. In its middle course the Daua has cut a deep narrow valley through the plain; lower down it bends N.E. to its junction with the Ganale. The river is not deep and can be forded in many places; the banks are fringed with thick bush and dom-palms. At the junction of the Ganale and the Web the river is swift-flowing and 85 yards across; just below the Daua confluence it is 200 yds. wide, the altitude here—300 m. in a direct line from the source of the Ganale—being only 590 ft.
Below the Daua the river, now known as the Juba, receives no tributary of importance. It first flows in a valley bounded, especially towards the west, by the escarpments of a high plateau, and containing the towns of Lugh (in 3° 50′ N., the centre of active trade), Bardera, 387 m. above the mouth, and Saranli—the last two on opposite sides of the stream, in 2° 20′ N., a crossing-place for caravans. Beyond 1° 45′ N. the country becomes more level and the course of the river very tortuous. On the west a series of small lakes and backwaters receives water from the Juba during the rains. Just south of the equator channels from the long, branching Lake Deshekwama or Hardinge, fed by the Lakdera river, enter from the west, and in 0° 15′ S. the Juba enters the sea across a dangerous bar, which has only one fathom of water at high tide.
From its mouth to 20 m. above Bardera, where at 2° 35′ N. rapids occur, the Juba is navigable by shallow-draught steamers, having a general depth of from 4 to 12 ft., though shallower in places. Just above its mouth it is a fine stream 250 yds. wide, with a current of 2½ knots. Below the mountainous region of the headstreams the Juba and its tributaries flow through a country generally arid away from the banks of the streams. The soil is sandy, covered either with thorn-scrub or rank grass, which in the rainy season affords herbage for the herds of cattle, sheep and camels owned by the Boran Gallas and the Somali who inhabit the district. But by the banks of the lower river the character of the country changes. In this district, known as Gosha, are considerable tracts of forest, and the level of flood water is higher than much of the surrounding land. This low-lying fertile belt stretches along the river for about 300 m., but is not more than a mile or two wide. In the river valley maize, rice, cotton and other crops are cultivated. From Gobwen, a trading settlement about 3 m. above the mouth of the Juba, a road runs S.W. to the seaport of Kismayu, 10 m. distant.
The lower Juba was ascended in 1865 in a steamer by Baron Karl von der Decken, who was murdered by Somali at Bardera, but the river system remained otherwise almost unknown until after 1890. In 1891 a survey of its lower course was executed by Captain F. G. Dundas of the British navy, while in 1892-1893 its headstreams were explored by the Italian officers, Captains Vittorio, Bottego and Grixoni, the former of whom disproved the supposed connexion of the Omo (see Rudolf, Lake) with the Juba system. It has since been further explored by Prince Eugenio Ruspoli, by Bottego’s second expedition (1895), by Donaldson Smith, A. E. Butter, Captain P. Maud of the British army, and others. The river, from its mouth to the confluence of the Daua and Ganale, forms the frontier between the British East Africa protectorate and Italian Somaliland; and from that point to about 4° 20′ N. the Daua is the boundary between British and Abyssinian territory.
