6 No. 96 GEOGRAPHY : EAST AFRICA

River Juba consists of arid thorn -covered steppe

(mostly under 2,000 ft. above sea -level), which slopes eastwards and south -eastwards from the region of the Laikipia plateau. This steppe region is in some places almost a desert, although there are occasional wells and oases .

Rivers and Lakes Owing to the comparative closeness of the eastern water -parting to the sea, there are no very large rivers. The most important are those of the coast area—the Juba , the Tana, and the Sabaki . There are three drainage areas : ( a ) that of the coast, ( b ) that of the Rift Valley, and ( c ) that of Victoria Nyanza.

( a) The River Juba rises in the Abyssinian high lands , and touches British East Africa at about 42° east longitude and 4° 10' north latitude, from this point forming the frontier between British East Africa and Italian Somaliland . It is navigable to light draught river steamers as far as Yonte all the year round, and in the wet season as far as Bardera . The Gwaso Nyiro River, which drains the Laikipia plateau and the northern slopes of Mount Kenya, flows into the Lorian swamp ; it belongs to the Juba system , with which it is connected in very wet seasons by the DeshekWamaswamp and the Lakdera.

The River Tana rises in the Aberdare Mountains, and drains the eastern and southern slopes of Mount Kenya, the Kikuyu country, and the plains of Tana land . Its principal tributary is the Thika . The valleys of the Juba and Tana have a rich alluvial soil and abundant vegetation. On both rivers there are large tracts of forest, and on the Upper Juba there is a considerable amount of cultivation.

The River Sabaki, which is known in its upper course as the Athi , drainsthe Ukamba country and the plains south of Nairobi. Its principal tributary is the Tsavo, on the right bank .

(b ) The drainage area of the Rift Valley contains no important rivers, since it is very narrow in the only