ABSTRACT
Northern Nigeria has a wide range of rainfall conditions, varying from an average annual rainfall of 60 inches in the southern-most parts to 15 inches in the extreme north. In all cases precipitation occurs during only limited portions of the year and during the dry season, crop cultivation is virtually at a standstill. Owing to the ever-present problem of a shortage of water in most of the rivers in Northern Nigeria and the increasing demand for food and fibre, it is essential to tap the groundwater supplies as this is the largest available source of fresh water on earth. The object of this study is to determine (i) the existence and extent of groundwater inaa river basin, (ii) the theoretical and practical yield of shallow wells situated in a dry river bed, (iii) the effective method of retaining banks in such wells (iv) the suitability of the water and land for irrigation practices, (v) reliable and inexpensive methods of raising the water for irrigation purposes, and (vi) whether such a project is economically desirable. The area chosen for the study is the Kubanni River Basin which lies almost in the centre of the Loess Plain soils- Map I. The Loess Plain soils are reputed to be very excellent agricultural land as they are formed by infilling of fine eaolian drift on a sedentary iron pan peneplain. The whole of Zaria Province, southern parts of Katsina, Kano and smaller areas adjoining Sokoto and Niger are areas in this soil unit. The results of this study may be reliably used in those areas mentioned above and all other similar areas in Nigeria without the necessity of having to make expensive trials. The methods of measurement and analysis are discussed in the text. It is shown that for irrigation purposes the quality of water from the shallow excavation in the river bed, rather than the quality, proves the limiting factor.