ABSTRACT
Drought is one of the most prominent, costly natural disasters posing significant effects on infrastructure and socioenvironmental systems. With its devastating impacts on widespread sectors such as agriculture, energy, water resources, environment, and human health, it has turned into a potential multidisciplinary research topic. Drought is the persistent deficiency of water for a prolonged period compared to the climatological mean over a region. There are mainly four types of droughts, commonly known as meteorological, agricultural, hydrological, and socioeconomic droughts. Meteorological drought is characterized by a persistent deficit in precipitation compared to the long-term mean. Agricultural drought is attributed to a sustained decline in soil moisture, whereas a prolonged reduction in surface and/or groundwater causes hydrological drought. Socioeconomic drought is often the combined effect of all other types of droughts and has wider spatial, temporal, and sectoral (e.g., water resources, agriculture, and energy) coverage. Meteorological drought may occur frequently; the other droughts (in particular hydrological and socioeconomic droughts) are less frequent and often require months to years to take place because they occur when the precipitation deficit is enough to significantly reduce soil moisture, streamflows, and groundwater levels.
