Modeling in the USACE US Army Corps of Engineers BUILDING STRONG ® Bruce Ebersole U. S. Army Engineer Research and Development Center Coastal & Hydraulics Laboratory

Purpose of Our Organization Conduct basic and applied R&D and cost-reimbursible engineering services in support of USACE and other customers USACE Military Mission USACE Civil Works Mission (areas of model applications) Modeling in Watersheds, Rivers, Estuaries, Coasts (Surface Water and Ground Water) Navigation –Structures (locks, gates, dams, jetties, training dikes) –Channels (safe navigation, operations, maintenance, effects on environment) –Dredged material management and environmental effects Flood Risk Management –Levees, reservoirs and water control structures –Beach nourishment –Seawalls breakwaters and revetments Environmental Restoration –Beneficial uses of dredge material –Wetland creation –Water quality and ecosystem response

Modeling Environment Wide range of model types: watershed and overland flow, surface-groundwater interaction, riverine estuarine and coastal water circulation at different scales, wave growth and transformation at different scales, nearshore dynamics, sediment transport and morphology change in various regimes and for different levels of sediment bed complexity, water quality, ecosystem response, macro-scale modeling Develop our own models or enhance models produced by others Usually developed in partnership w other partners, usually academic partners Usually apply our own models, occasionally apply someone else’s model to meet customer needs; we usually decide Solutions to problems generally focused on modeling in shallow water (depths usually less than 50 ft), or as needed to support solutions (wave and storm surge modeling are examples of exceptions)

Bottlenecks and Deficiencies Relatively lower accuracy levels for some desired end state modeling: sediment transport and morphology, ecologic response Nonlinear dependence on water models drives need to improve them also Not enough emphasis on physical processes R&D Lack of R&D funding Uncertainty in long-term modeling Conflict between desire for accurate integrated coupled modeling, complexity of doing it, and desire for computational efficiency, particularly for long-term and/or regional-scale modeling

Transition and Transfer of Models Model Test and Evaluation during R&D, test problems and field cases Shakedown during first few applications by developers and evaluation w field data sets (always encouraged) Models transferred to USACE and other users via workshops, model documentation; we train users Close tech support to other users doing applications, evaluation with field data sets encouraged Use of XMS user interface environment – middleware produced primarily under contract Some development of our own user environment software, primarily hpc environment

How can the Test Bed Help Us? Organized environment for model predictive skill evaluation (comprehensive regional, synoptic scale data sets) Assess accuracy of ocean-scale model results that we use as BCs Value of added resolution vs computational effort Means for evaluating R&D process advancements Must be objective evaluation