The northern half, which is inhabited by the Ababda, belongs to Egypt; the southern portion, inhabited by the Bisharin and the Amarar, etc., near Suakin, belongs to the Sudan. Although on many maps this country is generally labelled “Nubian Desert,” much of it is by no means desert in the true sense of the word. Comparatively little is known even now of the more southern districts[45] of the Atbai, and the following descriptive notes must be taken to apply chiefly to the country between north lat. 21° and 22° 30′.
Bisharin country.The country of the Bisharin, which is bounded on the north by an irregular line rather north of lat. 22°, and to the south extends as far as Mitateb on the Atbara, contains wide stretches of gravelly, sandy, or stony desert, intersected by frequent bare sandstone and granite ranges, but, at the same time, on the eastern side especially, it contains many more or less fertile and quite luxuriantly wooded wadis, in which water is sometimes found within 2 or 3 feet of the surface.
Drainage.East of the railway the hills become more frequent and larger, and the drainage lines more conspicuous.
Generally speaking, the watershed between the Nile and the Red Sea, which lies between 35° and 35° 30′ E. long., consists of a mass of hills from 30 to 40 miles in width. These hills, which consist of agglomerations of rather small features, out of which a bolder peak, such as J. Eigat, occasionally rises, are intersected by very numerous rocky khors, which feed a few large and well-wooded wadis. West of the watershed, from as far south as 20° 30′, all the drainage escapes north by the wadis Alagi and Gabgaba, which unite to the east of Korosko and join the Nile near Sayala.
Of these the Gabgaba has the longest course, as its head waters rise much further south than those of the Alagi. Much of its basin is still unexplored, in fact, the only well known portion is the plain south-east of Murrat wells, which is painfully arid and deficient in vegetation.
Many of the wadis, however, that descend to it on the east are well wooded as long as they are in the hills, and even for a few miles after they have emerged from them.
The scheme of drainage here is exactly the reverse of that west of the railway.
Instead of water-courses beginning broad and ending narrow and deep, here they commence with narrow defined rocky channels, gradually becoming broader, sandier, of more gentle slope, and in many places with fine trees and much “tabas” grass. When the hills are left, however, the trees die away, the grass disappears, and the bed becomes ill-defined or completely lost. South of the parallel of Murrat the country appears to become more open, and probably very wide plains exist with little to offer to even a desert Arab.
South of the Gabgaba Basin, the drainage from the watershed descends nearly due west by several large wadis, which have at various times given trouble to the railway. Owing to the outcrop of rocks near the river between Abu Hamed and Berber, the beds of these wadis become restricted as they approach the river, with the usual result as regards spates and floods.
Drainage east of watershed.On the east of the watershed the wadis, after leaving the hills on which they rise, traverse a range of granite hills, and thence flow, generally in a north-east direction, to the maritime plain of the Red Sea.