IDENTIFICATION AND MAPPING OF PLAYA LAKES WITHIN A GIS ENVIRONMENT FOR THE HIGH PLAINS OF KANSAS

Small, internally drained, ephemeral lakes, referred to as playas, are ubiquitous features on the High Plains of western Kansas. Playas are important features on the High Plains because they focus recharge to the heavily utilized Ogallala Aquifer. Although playas are a vital resource, an accurate inventory does not currently exist for Kansas. Previous researchers have mapped Kansas playas based on soils associations; however, accuracy of these methods is unknown. This research proposes new methods of playa identification and mapping utilizing geographic information system (GIS) data coupled with field verification. GIS data includes National Agriculture Inventory Program (NAIP) color aerial photography with statewide coverage at 2 meter resolution for the years 2003, 2004, and 2005, digital raster graphics (DRGs), Natural Resources Conservation Service Soil Survey Geographic Database (SSURGO) data, and political boundary data. Playas are mapped at the county level one section or square mile at a time by “heads-up” digitizing. NAIP aerial photography is visually inspected and potential playas are identified by year. Outlines of potential playas are digitized, or if a playa is visible on multiple sets of aerial photographs, the largest of the three playas is digitized and saved within a county-level GIS playa database. Each county database includes playa area, absence or presence on each of the three years of NAIP photography, absence or presence of a depression on associated DRGs, and absence or presence of hydric soils based on SSURGO data. This ongoing research project involves identifying and mapping playas for the 46 counties of western Kansas.