An Innovative Method for Estimating Soil Retention at a Continental Scale
Citation:
Cada, P., M. Mehaffey, AND A. Neale. An Innovative Method for Estimating Soil Retention at a Continental Scale. US-IALE Conference, Baltimore, MD, April 09 - 13, 2017.
Impact/Purpose:
The approach was designed to derive a quantitative approximation of the ecological services provided by vegetative cover, management practices, and other surface features with respect to protecting soils from the erosion processes of detachment, transport, and deposition across the continental US for incorporation into the EnviroAtlas.
Description:
Planning for a sustainable future should include an accounting of services currently provided by ecosystems such as erosion control. Retention of soil improves fertility, increases water retention, and decreases sedimentation in streams and rivers. Landscapes patterns that facilitate these services could help reduce costs for flood control, dredging of reservoirs and waterways, while maintaining habitat for fish and other species important to recreational and tourism industries. Landscape scale geospatial data available for the continental United States was leveraged to estimate sediment erosion (RUSLE-based, Renard, et al. 1997) employing recent geospatial techniques of sediment delivery ratio (SDR) estimation (Cavalli, et al. 2013). The approach was designed to derive a quantitative approximation of the ecological services provided by vegetative cover, management practices, and other surface features with respect to protecting soils from the erosion processes of detachment, transport, and deposition. Quantities of soil retained on the landscape and potential erosion for multiple land cover scenarios relative to current (NLCD 2011) conditions were calculated for each calendar month, and summed to yield annual estimations at a 30-meter grid cell. Continental-scale data used included MODIS NDVI data (2000-2014) to estimate monthly USLE C-factors, gridded soil survey geographic (gSSURGO) soils data (annual USLE K factor), PRISM rainfall data (monthly USLE R factor), and 30-meter resolution National Elevation Data (annual USLE L & S factors and SDR). Final products are estimated total phosphorus and sediment loads for all 12-digit Hydrologic Unit Code (HUC) watersheds for the continental United States for each land cover scenario.
