1 SUSTAINABLE MANAGEMENT OF DROUGHT AND DESERTIFICATION IN NIGERIA 1 Dogara Bashir National Water Resources Institute, Kaduna 1.0 INTRODUCTION Although characterized by the collapse of the underlying ecological basis of traditional agriculture, desertification is an environmental problem born out of the interplay of natural forces and human mismanagement. The United Nations Convention to Combat Desertification (UNCCD) also acknowledges the complex interactions of human activities and climatic variations as the cause of desertification. The Convention defines desertification as land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities. Such human activities may be as a result of political, social, cultural and/or economic factors. Drought is another complex phenomenon, closely associated with desertification. UNCCD defines drought as a naturally occurring phenomenon that exists when precipitation has been significantly below normal recorded levels, causing serious hydrological imbalances that adversely affect land resource production systems. Basically, drought is characterized by conditions of water deficit. The National Drought Preparedness Plan (Anon., 2005) recognized three types of drought: meteorological, agricultural and hydrological. While meteorological drought results from a prolonged deficiency and/or poor distribution of rainfall, agricultural drought is said to occur when evapotranspirative demands of crops and vegetation could not be met. Hydrological drought occurs when water table continues to fall as a result of declining groundwater recharge. The process of desertification is generally perceived to be slow and therefore apparently inconspicuous. Even though figures are usually given as rates of advancement of the desert, its frontiers can hardly be seen to be spreading. In dry years or seasons, the desert could be seen to be expanding only for it to shrink back in wet years or seasons. What may actually be happening is that isolated areas that are degraded due to human activities and/or climatic variations expand subtly over time and eventually merge. Subsequent human activities will accelerate the degradation until the land is bereft of vegetation and turns into a desert. Drought, especially if prolonged and/or repeated at short intervals, exacerbates and aids the process of desertification. The slow but steady desertification of vast areas of northern parts of Nigeria coupled with continuous land cultivation and massive deforestation have resulted in the destruction of much of the natural vegetation to the extent that only traces of it remain. This lack of vegetative cover coupled with severe aridity, steady winds, occasional violent air currents and a flat topography led to large scale movements of soil. This paper gives a brief account of the extent of desertification in Nigeria, its causes, the efforts being made to combat it and finally recommends some strategies to enhance the efforts. 2.0 EXTENT OF DESERTIFICATION IN NIGERIA It has since been noticed that processes of desertification are progressing southward at alarming rates. This is attested by the visible changes in vegetation cover in the affected areas, over the years. For example, Table 1 shows the changes in the dominant vegetation and land use classes in Yobe State (one of the critically desertified states) between 1976/78 and 1993/95. While areas covered by shrubs/grasses, grassland and freshwater marshland/swamp decreased by 39%, 44% and 42% respectively, areas under sand dunes, gullies and extensive agriculture with denuded had increased by 395%, 341% and 206% respectively. 1 Lead paper presented at the 1 st National Summit on the Environment: Greening the Environment for Sustainable Economic Development held at Transcorp Hilton, Abuja on 20 th to 21 st October, 2008.