METHODS USED FOR ANALYZING THE CUMULATIVE WATERSHED EFFECTS OF FUEL MANAGEMENT ON SEDIMENT IN THE EASTERN UNITED STATES

Abstract—This paper reviews the methods in use since 2000 to analyze the cumulative watershed effect (CWE) of sediment from fuel management activities within forestlands of the eastern United States, and evaluates how well current methods provide the information needed to meet legal expectations. The two sediment hazard rating models currently being used are the Erosion and Sediment Yield (EASY) and the Aquatic Cumulative Effects (ACE) models. Both are lumped-parameter models based on the USLE that predict sediment yield at the outlet point of a watershed based on the activities and conditions present or proposed. The EASY and ACE models use the same general procedural steps and compute erosion from forest areas using similar data sources and formula. They differ in how the CWE analysis area is determined, how they compute non-forest and road erosion, and how model results are interpreted. Both models can provide users with information needed to address most of the legal expectations for CWE analysis, but both suffer from lack of validation. Comments are offered on helpful features for future models and the need for knowledgeable model users