Effective erosion conservation screening tool: sharpening conservation placement by marrying physical modeling and stakeholder validation.
Primary Author: Ames Fowler
Faculty Sponsor: Jan Boll
Primary College/Unit: Voiland College of Engineering and Architecture
Category: Agricultural and Natural Resource Sciences
Persistent, unsustainable erosion rates on agricultural land and limited conservation funds motivate the identification of critical source areas for the effective selection and placement of best management practices (BMPs). Currently, national conservation funds are available on a case-by-case basis. There is no watershed-planning approach that identifies hydrologically sensitive areas at the field scale. The Hydrologic Character Tool (HCT) is a simplified formulation of the Water Erosion Prediction Project (WEPP) model previously developed to fit this need but has yet to be adopted for spatial use.
In this study, the HCT framework is applied to the Palouse River Watershed to determine 30-year average distributed erosion and hydrological flows. Publicly available data for climate, slope, and soil depth at a 30-meter resolution allow field scale erosion “hotspots” to be identified. Three tillage practice scenarios evaluate current conservation effectiveness. The tool was assessed by a global parameter sensitivity and infield stakeholder verification.
Model results suggest a small area of the Palouse River Watershed produces disproportionally high erosion rates. The mean erosion rates decrease sharply with decreases in soil disturbance, but the erosion rate distribution from the land type patterning associated with landscape features (e.g. soil depth, slope, etc.) persist. In addition to field scale heterogeneity – regional scale patterning associated with climate and soil formation create a gradient of critical source area density. This erosion and hydrology screening tool provides a linkage between watershed processes and field-by-field conservation efforts serving to make conservation planning more physically robust and cost effective.