EPSCoR Research Fellows: NSF: Enhancing Groundwater and Saltwater Intrusion Modeling in Coastal Aquifers: The Integration of Conduit Flow Process with 3D Connected Heterogeneity

Coastal aquifers are vital for residential, agricultural, and industrial water supplies in coastal regions. They also play a critical role in sustaining coastal ecosystems, facilitating nutrient cycling, and supporting diverse species. However, these resources are threatened by saltwater intrusion, exacerbated by climate change-induced sea level rise (SLR) and anthropogenic stressors. The challenges posed by saltwater intrusion are particularly evident in the coastal regions of Hawaii, where groundwater accounts for about 99% of the domestic water supply and half of the state’s total freshwater usage. This EPSCoR Research Infrastructure Improvement (RII): EPSCoR Research Fellows project will provide a fellowship to an Assistant Professor and training for a graduate student at the University of Hawaii at Manoa (UHM). This work will be conducted in collaboration with researchers at the Lawrence Berkeley National Laboratory (LBNL). The fellowship will develop a state-of-the-art modeling framework to provide a mechanistic understanding of saltwater intrusion within volcanic coastal aquifers. This project will engage underrepresented students in research activities, enhancing their theoretical knowledge and practical skills in groundwater modeling. The results from this fellowship will lay the foundation for innovative management strategies to address saltwater intrusion and other emerging environmental challenges across the State of Hawaii and in regions with similar geological settings.

This fellowship will have a transformative impact on the PI’s research career and benefit his home institution and jurisdiction. The proposed research will leverage the PI’s expertise in modeling saltwater intrusion within 3D conduit-type heterogeneous aquifers alongside LBNL’s specialization in modeling discrete-continuum flow processes. The PI and one graduate student will make four collaborative visits to LBNL. The goal of these research-focused activities is to develop a state-of-the-art modeling framework capable of capturing the conduit flow process and the 3D-connected heterogeneity of volcanic aquifers. This development will improve predictions of the temporal and spatial scales of saltwater intrusion in coastal volcanic aquifers. The modeling efforts will also be expanded to assess the impacts of SLR and excessive groundwater withdrawal on the dynamics of saltwater intrusion in coastal volcanic aquifers. This cutting-edge groundwater modeling will broaden the PI’s investigative scope to address various challenges of modeling saltwater intrusion in highly heterogeneous aquifer systems, with a particular focus on Hawaiian coastal regions. This project will establish a sustainable partnership with researchers at LBNL to enhance the groundwater modeling research infrastructure at UHM. The enhanced knowledge from this fellowship will serve as a crucial link, connecting scientific research with practical application, and facilitating the development of targeted mitigation strategies. These strategies, grounded in a mechanistic understanding of the saltwater intrusion processes in volcanic coastal aquifers, will be designed to safeguard the recreational, economic, and ecological value of coastal freshwater resources, ensuring their long-term sustainability for future generations in the State of Hawaii.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Award Number: 2429852
Principal Investigator: Xiaolong Geng
Funds Obligated: $299,920
State: HI