SWAT vs. RUSLE: Which better predicts benthic habitat condition?

Abstract

Excessive sediment loading to streams can harm benthic species habitat. Human driven land cover and land use changes increase soil erosion and sediment loading rates over time. Conservation and management agencies are increasingly restoring vegetation along riparian zones as a means to protect water quality and instream habitat; however, time and funding are limited. Widespread habitat degradation caused by sediment deposition increases the need for a prioritization framework to improve project efficiency. We developed and compared decision-support frameworks to predict instream silt cover and embeddedness— threats to benthic species. These frameworks statistically integrate landscape characteristics and estimates of soil loss derived from the Revised Universal Soil Loss Equation (RUSLE) or sediment loading computed using the Soil and Water Assessment Tool (SWAT). Results from the comparisons of statistical models discussed within suggest that upland soil erosion and estimated soil loading only partially explain patterns of silt cover and embeddedness.