The Department of Defense (DoD) coastal installations span the globe and require insight on potential sea level rise and saltwater encroachment that may threaten that infrastructure. The DoD-led Coastal Assessment Regional Scenario Working Group supports the develop tools that provide the needed insight. One tool example is the DoD Regional Sea Level Database (DRSL) which provides sea level change information relevant to each coastal installation. In 2022, SERDP funded projects to continue tool development to examine DoD coastal installations with subsurface physical infrastructure vulnerable to saltwater intrusion.

Cross-sectional diagram of a coastal aquifer undergoing sea-level rise.

One project led by Dr. Dipankar Dwivedi from Lawrence Berkeley National Laboratory will develop a toolset with multiple reduced-order models (ROMs) to estimate changes in groundwater levels and salinity intrusion. The development of this toolset seeks to address common obstacles for decision-makers in using traditional high-fidelity mechanistic modelling, including cost, complexity, and site specificity/exclusivity. The resulting end product will be a risk management summary for DoD site managers that carefully evaluates multiple ROM choice, thereby capturing the range of responses for groundwater and saltwater levels expected under a changing climate (Project Overview).

In a second project, Dr. Christopher Patterson of the Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) will seek to create a mathematical modeling tool designed to predict current and future water levels and salinity profiles in aquifers. This tool will require lower computational effort than traditional fully coupled variable density modeling approaches. An additional project objective the development of an efficient graphical representation of inundation caused by extreme water levels that are associated with storm surge and high tides coupled with sea rise. This modeling platform will be integrated into a commercial groundwater modeling graphical user interface for DoD installations using sea-level change and extreme water level scenarios obtained from the DRSL database (Project Overview).

Additionally, Dr. James Jawitz at the University of Florida aims to develop reduced-order frameworks to assess groundwater-related risks to coastal infrastructure. This need stems from predicted changes in sea level and recharge, which are expected to increase saltwater intrusion into coastal aquifers and change water table elevations. These frameworks will be suitable for application towards DoD coastal infrastructure vulnerable to groundwater-related sea level rise risk (Project Overview).

Finally, Dr. Benjamin Hamlington at the NASA Jet Propulsion Laboratory will seek to produce and implement a model that estimates changes to coastal underwater levels and the position of the freshwater-saltwater interface in response to projected regional sea-level rise. This model will assess potential saltwater intrusion impacts at DoD installations using a reduced-order model that is scalable to large regions while also addressing the need for local specificity in complex coastal regions (Project Overview).Each of these new projects will provide an advance insight into estimated sea-level rise and its potential effects on coastal DoD installations. For more information on SERDP and ESTCP climate change impact prediction tools and modeling research, visit the Sea Level Rise Tools page.