aridregion

An arid region is a geographic area characterized by low rainfall and high evaporation, resulting in limited surface water, sparse vegetation, and desert or semi-desert landscapes. In climate classifications, arid regions fall largely within desert (BW) and semi-arid (BSk, BSh) categories, with annual precipitation typically well below potential evapotranspiration.

Hydrology and landscape: Most arid regions receive less than 250–500 millimeters of rain per year, and rainfall is irregular, often occurring in short, intense bursts. Soils are frequently shallow, salty, and low in organic matter, and landscapes commonly feature dunes, rocky plateaus, and salt flats. Groundwater may exist in aquifers, but access is often limited and variable.

Ecology and human use: Flora and fauna are adapted to drought and extreme temperatures; many plants have deep or extensive root systems and water-storage traits, while animals include reptiles, small mammals, and camelids. Human livelihoods typically rely on nomadic herding, oasis agriculture, or irrigation-based farming. Arid regions are highly sensitive to water management and land-use pressures.

Climate change and management: Arid regions confront increased heat, altered precipitation patterns, and the expansion of desert conditions in some areas. Desertification, dust storms, and habitat loss pose risks to ecosystems and livelihoods. Management approaches emphasize water-efficient irrigation, rainwater harvesting, sustainable grazing, land restoration, and policies that reduce water waste and support adaptive practices.