DEVELOPMENT AND DEMONSTRATION OF A HYBRID MODELING CAPABILITY WITHIN THE FORT BENNING HSPF WATERSHED MODEL:REFINEMENT OF UNPAVED ROAD SIMULATION USING WEPP:ROAD

摘要

A four-year project funded by the Strategic Environmental Research and Development Program (SERDP) is in progress to develop a comprehensive watershed management model (using EPA's BASINS modeling system and HSPF watershed model) for Fort Benning, Georgia. The resulting Fort Benning Watershed Model addresses impacts on watershed hydrology, water quality and related ecosystems resulting from military activities and natural resources management. The baseline model has been applied to current watershed conditions. An incremental objective of the project is to enhance the baseline watershed model that was developed during the first three project years to better reflect impacts from military training activities. Road erosion is commonly a major contributor to sediment production within forest watersheds such as the one that encompasses Fort Benning. Design, construction and management of unpaved roads at Fort Benning require methods and models for estimating road erosion that provide a high level of detail that surpasses the capabilities currently provided by HSPF and similar watershed-scale models. Nonetheless, the full impact of road management measures ultimately needs to be evaluated within the holistic watershed context. To address this need, a generalized capability has been developed to perform hybrid model applications in which HSPF can be used for modeling catchment-scale phenomena, while one or more field- or hillslope-scale models featuring more detailed process formulations for specific activities, sources, or land uses are run in parallel to HSPF. To make available a more robust set of formulations for simulating sediment washoff from Fort Benning's unpaved forest roads, USDA's WEPP:Road Model is being applied as a demonstration of the hybrid modeling capability that has been developed for HSPF.