ABSTRACT
Drought is an insidious natural hazard that results from a deficiency of precipitation from average or "normal" that, when extended over a season or longer, results in water supplies that are insufficient to meet the demands of human activities and the environment. This chapter discusses drought in terms of both its natural characteristics and its human dimensions, as these shape the effectiveness of responses during water-related crises. Drought impacts are nonstructural and spread over larger geographical areas and temporal scales than are damages that result from other natural hazards such as floods, tropical storms, and earthquakes. In technical terms, droughts differ from one another in three essential characteristics: intensity, duration, and spatial coverage. A drought early warning and information system (DEWIS) is designed to identify trends of key meteorological, hydrological, and social indicators to predict both the occurrence and the impact of a particular drought and to elicit appropriate mitigation and response measures.
