ABSTRACT
Drought is often called a ‘creeping’ or slow-onset hazard because it develops slowly. Droughts have a prolonged duration, impacting regions for several months to years. Single events can extend over regions that are subcontinental in scale and cover multiple countries at a time. Droughts occur when there is a shortage of water in the landscape across a distinct period. However, droughts are not confined to areas of low rainfall or other precipitation. The disaster consequences of drought increase with their severity and duration. This chapter recognises four different categories of drought: meteorological, hydrological, agricultural and famine. Meteorological drought is defined on statistical criteria relating to shortfalls of precipitation alone. Hydrological drought occurs when streamflows and/or groundwater levels are sufficiently reduced to threaten water resources. Agricultural drought has implications for food production, with the main consequences being reduced crop and animal production. Famine droughts are complex, where hydrometeorological conditions are exacerbated by the social relations organising resource use and by economic insecurity. Risk assessments are improving our understanding of drought, resulting from our increased understanding of climate variability and its implications for agriculture, food supplies and the welfare of rural communities. Management practices require proactive approaches that integrate environmental data, alongside monitoring and forecasting of significant shortfalls in seasonal rainfall or snow/ice melt with efficient and just food and nutrition management.
