droughtdominated

Droughtdominated is a term used in climatology and hydrology to describe a climate or hydroclimate regime in which drought conditions predominate over periods of wetness, resulting in persistent moisture deficits that affect soils, streams, and groundwater. The term can apply to a specific region during a drought period or to longer-term climate states characterized by recurrent or sustained dryness.

Causes and indicators: Droughtdominated states arise from shifts in precipitation patterns, higher evapotranspiration due to heat, and feedbacks from depleted soil moisture. It is diagnosed using drought indices such as the Palmer Drought Severity Index, the Standardized Precipitation Evapotranspiration Index (SPEI), and basin-scale hydrological indicators that reflect deficits in precipitation, soil moisture, and streamflow over weeks to years.

Characteristics and impacts: In droughtdominated regimes, soil moisture remains low, groundwater may be depleted, and reservoir levels decline. Agriculture and water supply can be affected, with ecological and economic consequences, including increased wildfire risk and stress on aquatic ecosystems.

Regional relevance: The concept is used to describe parts of the globe where dryness is a recurrent feature, notably arid and semi-arid regions, the Mediterranean and parts of southern Africa, North America’s southwestern states, and portions of Australia. However, seasonal and interannual variability means that droughtdominated conditions are not uniform across all years.

Management and adaptation: Drought planning emphasizes water conservation, demand management, drought-resilient crops, groundwater governance, and monitoring systems that provide early warnings and support decision-making.

See also: drought, aridity, drought indices, climate variability, drought management.