| Definition of Drought |  |
| Definition of Drought | |
The most commonly used drought definitions are based on meteorological, agricultural hydrological and socioeconomic effects.
This type of drought is often defined by a period of substantially diminished precipitation duration and/or intensity. The commonly used definition of meteorological drought is an interval of time, generally of the order of months or years, during which the actual moisture supply at a given place consistently falls below the climatically appropriate moisture supply.
Agricultural drought occurs when there is inadequate soil moisture to meet the needs of a particular crop at a particular time. Agricultural drought usually occurs after meteorological drought but before hydrological drought and can also affect livestock and other agricultural operations.
Hydrological drought refers to deficiencies in surface and subsurface water supplies. It is measured as streamflow, snowpack, and as lake, reservoir and groundwater levels. There is usually a time lag between lack of rain or snow and less measurable water in streams, lakes and reservoirs, making hydrological measurements not the earliest indicators of drought.
Socioeconomic drought occurs when physical water shortages start to affect the health, well-being, and quality of life of the people, or when the drought starts to affect the supply and demand of an economic product.