Using Soils to Delineate South Dakota Physiographic Regions

Physiographic regions are natural landforms valuable for research and management landscape stratification. Accurate regional delineations may increase research sampling and management effectiveness. Soils data in the us. Department ofAgriculture Natural Resource Conservation Service (USDA-NRCS) State Soil Geographic Data Base (STATSGO) were used in a Geographic Information System to delineate 13 South Dakota physiographic regions. Soil mapping units were selected within physiographic regions in the STATSGO coverage in ARC/INFO to delineate geographic features. Several modifications to prior South Dakota physiographic region delineations are proposed. Soils data may be used to provide detailed and objective delineations ofnatural landforms. A map and briefdescription of South Dakota physiographic regions are presented. Physiographic regions consist of recurring landform patterns that reflect regional geology and weathering forces of past and present climates. The present interest in biodiversity and natural resource inventory with Gap Analysis (integrating natural resource distributions to identify critical, unprotected areas) has increased interest in physiographic regions. Scott et al.