Sabkhas

Sabkha is a flat, saline coastal or inland desert plain dominated by evaporites, formed in arid climates where high evaporation and low rainfall concentrate salts. The term comes from Arabic sabkha, meaning a flat salt-flat or saline surface.

Most sabkhas occur along arid coastal zones where tides or groundwater discharge periodically flood the flats. As water evaporates, salts precipitate, creating crusts of gypsum, halite, and other evaporite minerals. Inland sabkhas develop in closed basins with shallow water tables and episodic flooding from rainfall or groundwater discharge. Surfaces are often made of muds or sands overlying evaporite-rich substrates and may exhibit polygonal cracking and wind-sculpted textures.

Hydrology in sabkhas is characterized by extreme and fluctuating salinity, driven by tidal inflow, seasonal rainfall, and groundwater processes. Ecologically, life is sparse; halophytic vegetation may appear at margins, while microbial mats and salt-tolerant cyanobacteria commonly contribute to surface crusts and color bands.

Sedimentology and geology: sabkha deposits record sea-level changes and arid-climate conditions and can form significant evaporite sequences used to study paleoenvironmental history. They also influence land–sea interactions, coastal erosion, and groundwater chemistry.

Human use and threats: sabkhas have historically been sites for salt harvesting and remain of interest for mineral resources and geologic study. They are vulnerable to coastal development, groundwater extraction, mining, and climate-change–related changes in evaporation and sea level. They occur in arid coastal regions worldwide, including parts of the Persian Gulf, North Africa, and other arid zones.