Borku or
Borgu () is a region of
Central Africa, mostly in Northern
Chad, forming part of the transitional zone between the arid wastes of the Sahara and the fertile lands of the central
Sudan. It is bounded N. by the
Tibesti Mountains, and is in great measure occupied by lesser elevations belonging to the same system. These hills to the south and east merge into the plains of
Ouaddaï and
Darfur. South-west, in the direction of
Lake Chad, is the
Bodele basin. The drainage of the country is to the lake, but the numerous khors with which its surface is scored are mostly dry or contain water for brief periods only. A considerable part of the soil is light sand drifted about by the wind. The irrigated and fertile portions consist mainly of a number of valleys separated from each other by low and irregular limestone rocks. They furnish excellent dates. Barley is also cultivated. The northern valleys are inhabited by a settled population of
Toubou stock, known as the
Daza; the others are mainly visited by nomadic
Berber and
Arab tribes. The inhabitants own large numbers of goats and asses.