This project will assess potential saltwater intrusion impacts at Department of Defense (DoD) installations worldwide, where changes to groundwater quality and availability directly affect water supply, infrastructure integrity, and installation readiness. The project team will develop and implement a reduced-order model that is scalable to large regions while addressing the need for local specificity in complex coastal environments.

The project team will develop and implement a model that estimates changes to coastal groundwater levels and the position of the freshwater-saltwater interface in response to projected regional coastal changes. The significance of this work lies in synthesizing large-scale, high-resolution terrestrial and oceanic datasets while incorporating accurate regional coastal change projections. The result will be a scalable method that produces consistent global assessments. The core model will be evaluated in specific regions of increasing coastal complexity, where the topology of the coastline and topography may interact with coastal changes that drive saltwater intrusion from multiple directions. This tiered approach will allow for the development of an easily implemented, reduced-order global model that can be integrated with more regional sophisticated analyses to meet challenges of complex coastlines. The approach will lead to a high technology readiness level by the end of the project, and a detailed transition plan for incorporating the model into the DoD Regional Sea Level Database (DRSL) database.

The model will provide DoD installation managers with a consistent screening level of assessment of the threat of saltwater intrusion at all DoD installations across the globe (not just the continental United States), adding complexity as dictated by region-specific factors. The model will be designed for seamless integration into the DRSL database. As currently developed, the DRSL database provides consistent information across all installations. The project team has constructed the project and model with a strong view toward implementation into the DRSL database, recognizing that providing an assessment for only specific installations or specific regions would lead to installations where an assessment is out of scope or not possible. The approach is one of the first to synthesize existing large-scale high-resolution datasets in order to assess saltwater intrusion over global scales. This work takes advantage of National Aeronautics and Space Administration observational systems and products derived from these observations. As the satellite coastal observing network expands in the future, modeling approaches will grow in their usefulness and ability to project coastal impacts on DoD installations. (Anticipated Project Completion - 2026)