A SURVEY OF SALT PLAYAS ON THE LLANO ESTACADO

The Llano Estacado, also known as the Staked Plains or Southern High Plains, is a vast physiographic region located at the southern end of the Great Plains of North America. This immense stretch of elevated plains has long been recognized as a region that is distinct from surrounding areas. The key distinguishing feature is its exceptionally level surface; a surface that generally lacks flowing streams or other forms of organized drainage. One consequence of this lack of drainage is that rain tends to pool in numerous shallow basins called playas, forming ephemeral ponds called playa lakes. Playas are a characteristic feature of the Llano Estacado and provide its principal source of topographic variety in an otherwise flat and featureless landscape. There are two basic types of playas on the Llano Estacado — the more numerous, and relatively small, saucer-shaped freshwater playas and the larger, more irregular salt playas. This paper represents a detailed survey of salt playas on the Llano Estacado, also known as saline, alkali or salt lakes. The approach taken here was to first define the boundaries of the Llano Estacado and then identify all salt playas within the defined boundary. Once the playas were identified basic measurements of physical characteristics were obtained using aerial imagery. Measured physical characteristics include playa location (longitude and latitude), altitude above sea level, playa size (area, length, width) and playa shape (aspect ratio).