A drought is simply a long period (usually a season or more) of dry weather where less than normal or no precipitation falls.
Meteorological Drought is usually defined based on the degree of dryness (in comparison to some “normal” or average) and the duration of the dry period. Drought onset generally occurs with a meteorological drought.
Agricultural Drought links various characteristics of meteorological (or hydrological) drought to agricultural impacts, focusing on precipitation shortages, soil water deficits, reduced ground water or reservoir levels needed for crop irrigation.
Hydrological Drought usually occurs following periods of extended precipitation shortfalls that impact surface and/or sub-surface water supplies (i.e. streamflow, reservoir and lake levels, ground water), potentially resulting in significant societal impacts. Due to the fact that regions are interconnected by hydrologic systems, the impact of meteorological drought may extend well beyond the borders of the precipitation deficient area.
Drought can bring with it a range of negative economic (e.g. agricultural sector collapse), social (e.g. famine, disease outbreak) and environmental (e.g. soil degradation/erosion, habitat loss due to forest fires) impacts. In addition, as is often seen, the people most vulnerable to drought are those that come from marginalized groups/communities in society e.g. the poor and the elderly. Also severely impacted can be those persons that engage in agriculture based livelihoods.
Drought, however, is a disaster whose impacts can be mitigated. On a national scale, governments can be pro-active by creating food and water supply reserves for use should drought occur – especially in regions prone to this disaster. During drought steps can also be taken to ration and conserve available water supplies. On a more individual level, adapting lifestyles to more fully integrate water conservation practices into daily routines can also be imperative in easing effects of drought.