A GIS-based Approach to Identify and Map Playa Wetlands on the High Plains, Kansas, USA

Geographically and hydrologically isolated, ephemeral playa wetlands are ubiquitous features of the High Plains. Although playas are important landscape elements, few systematic inventories have been conducted, particularly on the Northern and Central High Plains. A comprehensive Geographic Information Systems database was created using versatile inventory techniques applicable for a variety of regions and wetland mapping projects. Utilizing several geospatial data sources, including high-resolution aerial imagery, digital raster graphics, and SSURGO soils data, 22,045 playas were identified in Kansas-more than doubling previous estimates. Playa surface area ranges from 0.03 ha to 188 ha, with a mean area of 1.65 ha. More than 80% are smaller than 2 ha and only about 400 playas (1.8%) are larger than 10 ha. Results indicate that previous playa inventories failed to identify most small playas, particularly those less than 2 ha because data sources were not of sufficient resolution. Additionally, playa identification criteria have not been consistent for previous playa inventories conducted throughout the High Plains. It is essential that criteria to identify playas are consistently applied in all playa studies to facilitate comparison and to establish trends for various playa attributes across the entire High Plains.