DETAILED SOIL PROPERTIES FROM SSURGO FOR USGS MODELING

Many environmental models need soil data to accurately represent vegetation growth, hydrological processes, erosion and sedimentation, and carbon storage and fluxes. For example, the quantity of soil organic carbon (SOC) stocks forms a foundation for understanding potential sequestration or release of carbon in the future in response to changes in land management and climate. The Soil Survey Geographic (SSURGO) database, developed by the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS), is now 86% complete for the conterminous United States. These data have much more spatial detail than the previous maps formed from the State Soil Geographic (STATSGO) data developed by NRCS in 1994. A new capability is being developed to extract information from the hundreds of attributes in the SSURGO database and provide the information as data layers ready for use in models. Simple queries are based solely on the SSURGO data. More complex queries show relationships between soil properties and other spatial data such as land cover, elevation, slope, aspect, relief, landscape position, hydrologic unit, and Federal land ownership status. The newly available data formats are expected to enable USGS scientists and DOI land managers to spatially improve their spatially explicit modeling of regional carbon dynamics, evapotranspiration, and vegetation growth.