SERDP has spent significant time and resources in the development of an engineering-level probabilistic model of underwater munitions burial and mobility. We have projects in all aspects of this problem: laboratory measurements and detailed, finite-element modeling of individual items, in-situ observations of collections of surrogate munitions, literature surveys of related fields, etc. All of these processes are driven by waves, currents, and the resulting sediment transport. The ability to know the conditions the underwater munitions were subjected to will be key to successful modeling.

During the latest Spring In-Progress Review Meeting, Dr. Margaret Palmsten from the U.S. Naval Research Laboratory briefed the Program Office and Technical Committee on updates regarding her SERDP project, “Probabilistic Environmental Modeling System for Munitions Mobility.” The overall focus is to develop recent hindcasts of waves, currents, and sediment transport, including uncertainties using a coupled modeling system. The project team will link hydrodynamic and morphodynamic models with a probabilistic model for munitions mobility, which is under development (MR-2645). Their approach hopes to provide better forcing conditions and a better understanding of the role of time-dependence and uncertainty in munitions mobility simulations. Ultimately, this will allow site managers to make informed decisions about munitions response resulting in the best use of use of available resources.

The project team has applied an existing Navy model, Delft3D, at the US Army Corps of Engineers Field Research Facility at Duck, NC, which included setting up a bathymetry grid, establishing boundary conditions, and obtaining updated bathymetry from remote sensing. Secondly, they generate model ensembles using a state-of-the-art method drawn from hydrologic modeling. Finally, Dr. Palmsten and her team have been able to simulate waves and currents as well as compare model results to observations. The model results were then integrated with the Underwater Munitions Expert System (UnMES) which output updated probabilities for burial, migration distance, and migration direction. We look forward to seeing the next results from Camp Pendleton!