Challenges to watershed modeling in forested mountainous environments

Abstract

Assessing the effects of management on streamflow and water quality in forested mountainous environments (FMEs) often involves the use of watershed modeling tools and techniques. Numerous models are available for this purpose, but to be useful to watershed managers a model must: 1) accurately predict management impacts, including cumulative watershed effects, 2) have program software that is readily accessible, preferably on the Internet, 3) be user friendly; 4) be well documented, and 5) be legally defendable in terms of the model's scientific basis, its' assumptions and limitations and the error and uncertainty in model output. The USDA Forest Service recently conducted an inventory and review of 25 water and sediment modeling tools to identify those which best meet these criteria. The six highest ranked models were DHSVM, FORest/Delta-Q, RI-WATSED, SEDMODL2, SWAT, and WEPP, all of which met the required criteria for application by Forest Service personnel. While these models represent the state-of-the-art in assessing management effects in FMEs, no one model or combination of models currently meets all of the needs of managers. In order to improve the utility of models for management use, model developers need to provide clearer statements of the intended use of the model, and the model assumptions and caveats, Tools and procedures to assess and report model error and uncertainty must be further developed, along with programs to train managers in their effective use. Managers need to provide monitoring data so that models can be validated under a range of conditions. By working together, managers and model developers can improve our ability to assess and predict the effects of management on soil and water resources within FMEs.

Citation

Hyde, Kevin; Woods, Scott; Potyondy, John. 2006. Challenges to watershed modeling in forested mountainous environments. In: Adaptive management of water resources; AWRA summer specialty conference; 2006 June 26-28; Missoula, MT. Middleburg, VA: American Water Resources Association. 5 p.