Global Positioning System/GIS-Based Approach for Modeling Erosion from Large Road Networks

Abstract

Sediment budget analyses require watershed scale evaluation of road erosion and delivery. The Watershed Erosion Prediction Project (WEPP) model, as developed by the USDA Forest Service, simulates sediment detachment and delivery for a road, fill, and buffer system. Time and budget constraints typically prevent a comprehensive sediment loading analysis using WEPP throughout a watershed. We present an automated approach to run the hillslope version of WEPP to simulate sediment detachment and delivery for a large road network. Road attributes are acquired from global positioning system-assisted road surveys and mapped in a geographic information system (GIS). After data manipulation in GIS and Excel, the required input files for WEPP are built. The approach can be applied to multiple road designs and climate regimes, with unique attributes for each road segment. We applied the automated approach to the