ABSTRACT
The alarm now being raised by governments and peopie will with regards to the threat of drought, dessication and desert-encroachment on the settlement form in Nigeria and especially Borno State is undoubtedly genuine. Desert-encroachment results largely from climatological, ecological and anthropogenic vagaries. This study look at the impact of desert-encroachment on the settlement form in Borno State with particular reference to a delineated area. The physical and socio-economic characteristics of the inhabitants are also studies. It was discovered that the structure of the buildings and the general form of the settlements shows some adaptation to desert conditions. The study also discovered functional relationship exists between the settlements of various hierarchies. The impact of the desert encroachment is noticeable on the physical environment and the socio-economic activities of the inhabitants in the delineated area. Such is manifested in the migratory movement of the people and livestock to areas that are yet under this environment vagaries; i.e., Southern part of Borno State. Principles for planning settlements in areas faced with the threat of encroachment of the desert that boarder on the siting and design of settlements to adapt to conditions while ensuring that the functional base of settlements is maintained are developed. Also strategies and policies for containment and planning of settlement are drawn up. These policy proposals are broad based. Conceptual planning models for the planning of settlements in the area under the threat of desert-encroachment are proposed.