Playa-Lunette Systems

• Playas are small, ephemeral, geographically-isolated, internally-drained wetlands.

• Lunettes are dunes found along the southern margin of some larger playas.

• Playa-lunette systems (PLSs) are common features in semi-arid and arid regions around the world, and they are particularly abundant on the High Plains of the central United States.

• These systems are especially useful for environmental reconstructions because they are influenced by fluvial, lacustrine, and eolian process, with the dominant geomorphic process at a given time being dependent upon prevailing environmental conditions.

Playa-Lunette System Functions

• Playas store water, which: decreases flooding, supports aquatic vegetation, provides essential wetland habitat, and promotes biogeochemical processes that improve water quality.

• Groundwater recharge may be 1-2 orders of magnitude greater in playas compared to uplands.

• Sediment and sediment-bound pollutants accumulate in playas, reducing pollution loads to streams.

• Archaeological material, spanning several cultural periods, are often preserved in lunettes.

Impacts to Playa-Lunette System Functions

• Much of the High Plains landscape, including playas, has been converted for agriculture, resulting in sedimentation of playas and decreased functionality.

• Road construction alters the natural hydrologic regime of playas and fragments playas and watersheds.

• Playas have been modified to serve a variety of purposes including crop production, trash dumps, feed lot effluent storage, and irrigation runoff storage.