A team of scientists at the University of Virginia generated new insights into how complex water systems behave under shifting environmental conditions. These findings can help communities better prepare for floods, droughts, and other water-related risks.

Farshad Hesamfar (a member of a Climate Collaborative team working on the Eastern Shore and the Coastlines and People project) and Sergio A. Barbosa (previously a Climate Fellow at the UVA Environmental Institute) worked with a team from UVA, including Thanh-Nhan-Duc Tran, Teresa Culver, Lawrence Band, and Venkataraman Lakshmi, to publish the article.

The research, which appeared in the Journal of Hydrology, offers an improved understanding of how water moves across landscapes and through connected surface and groundwater systems.  By applying a range of future climate projections, the team generated estimates for how much water actually reaches and replenishes the aquifer (groundwater recharge) and integrated them into a three-dimensional, density-dependent groundwater model. The simulations accounted for long-term sea-level rise along the Eastern Shore coastline. This work strengthens modeling approaches and predictive tools and helps decision-makers better anticipate changes in groundwater availability,  saltwater intrusion, and long-term resource stability.

The team focused on the Eastern Shore of Virginia. Approximately 70% of the world’s coastlines are situated where the topography keeps the water table near the land surface. In these systems, the water table cannot rise much with sea-level rise, reducing the fresh groundwater flow and making them more vulnerable to seawater intrusion. Virginia’s Eastern Shore is a low-lying peninsula between the Atlantic Ocean and Chesapeake Bay, where shallow water tables and proximity to the coast make the aquifer especially sensitive to both rainfall fluctuations and sea-level rise. 

Despite this, limited studies have investigated climate impacts on these groundwater dynamics, with most research focused on surface waters and ecosystem health. 

“The Eastern Shore of Virginia was a great place for us to conduct this research,” said Hesamfar. “This vibrant area has a community that is eager to make better decisions to reduce risk and protect resources."

"Our results show that uncertainty in climate-driven groundwater recharge due to changes in rainfall patterns can matter as much as sea-level rise for inland groundwater conditions,” continued Hesamfar. “Planning must account not just for average outcomes or one scenario, but for the full range of plausible futures.” 

Improved groundwater projections can help:

• Support climate-resilient water-supply planning
• Identify zones vulnerable to saltwater intrusion
• Inform infrastructure and septic-system risk assessments
• Guide long-term coastal adaptation strategies
• Strengthen decision-making under climate uncertainty

As climate variability increases and demand for water changes, understanding how recharge dynamics interact with sea-level rise will be critical for protecting drinking water supplies and infrastructure in coastal regions across the United States and globally.

Barbosa added, “Water challenges are becoming more complex as climate patterns shift. Our work provides tools and knowledge that can support more resilient planning, from climate variability and rising seas to sustaining water supplies.”