What is a playa?

A playa is specifically characterized as a basin that remains after a lake has evaporated, often found in arid or semi-arid regions. These landforms typically collect water from infrequent rain, creating a temporary lake that eventually dries up, leaving behind exposed sediment and sometimes salt flats. This geological feature demonstrates unique ecological and hydrological processes, often supporting distinct habitats when water is present.

The other concepts presented in the choices do not align with the definition of a playa. For instance, wetlands represent ecosystems that are saturated with water, contrasting with playas that typically dry out. Volcanic craters are formed by explosive volcanic activity and are not associated with the evaporation of a lake. Coastal areas with high salinity generally refer to environments influenced by ocean waters, which is distinct from the inland formation described by a playa. Thus, the identification of a playa as a basin left after a lake evaporates is accurate and highlights its geological relevance.