My research is focused on coastal and estuarine hydrodynamics, with a specific focus on understanding the effects of global sea-level rise and anthropogenic changes on inland and coastal water, through a combination of data analysis, analytical and numerical modeling, and theoretical analysis. Furthermore, I investigate the influence of natural and nature-based solutions on minimizing flooding, erosion, and runoff through integrated modeling of hydrodynamics and coastal morphology.

Assessing the effect of coral reef restoration location on coastal flood hazard along the San Juan Coastline, Puerto Rico

Coastal resilience has become a pressing global issue due to the growing vulnerability of coastlines to the effects of climate change. Nature-based solutions have emerged as a promising approach to coastal protection to not only enhance coastal resilience, but also restore critical ecosystems. Coral reef restoration has the potential to provide ecosystem services benefits; however, there are still key uncertainties in linking restoration design to reductions in coastal flood hazard under current and future climate conditions. In this study, we applied one-dimensional and two-dimensional numerical coastal engineering models, calibrated and validated using field data, to evaluate the effectiveness of coral restoration scenarios on coastal waves, water levels, and flooding along the coast of San Juan, Puerto Rico, U.S.A. Model results indicate a small reduction in maximum water levels under the proposed restoration scenarios. This underscores the importance of these endeavors, not only for ecological preservation but also for preventing further reef deterioration. Such preservation is essential for mitigating the increased coastal risks anticipated in the future. Results from this study provide information to guide policymakers and coastal managers in making informed decisions on viable restoration project design options. By systematically evaluating how restoration location impacts coastal flood hazards, communities can develop and implement proactive strategies to mitigate flood-related risk. In addition, by restoring coral reefs, communities can contribute to environmental preservation while ensuring sustainable development and protection of coastal environments.

A Blueprint to Greener Shorelines: Advancing the Effectiveness, Sustainability, and Widespread Adoption of Coastal Nature-Based Solutions Through Transdisciplinary Research

Coastal nature-based solutions (NbS) have emerged as powerful tools to enhance sustainable development and ecological restoration goals. As a rapidly growing field spanning across social, political, ecological, economic, and engineering disciplines, it is critical that researchers working in coastal NbS regularly attempt to identify emerging focal areas for scientific inquiry. We provide a transdisciplinary perspective (including biologists, engineers, oceanographers, geoscientists, economists, and facilitators of workforce training programs) of pertinent research questions that, if answered, will advance the effectiveness, sustainability, and widespread adoption of coastal NbS. These suggestions for future research highlight the necessity for diverse expertise and perspectives at every stage in planning, design, implementation, and monitoring coastal NbS.

Quantifying the benefits of wetland restoration under projected sea level rise

The capacity of vegetated coastal habitats to mitigate erosion and build elevation in response to sea-level rise (SLR) has led to growing interest in their application as Nature Based Solutions (NBS) for shoreline protection. However, a significant uncertainty in the performance of NBS is how these features will respond to future rates of SLR. In this study, we applied the Sea Level Affecting Marshes Model (SLAMM) to a fringing shoreline wetland complex that is directly adjacent to the primary runway of a regional airport in coastal North Carolina, US. The SLAMM model was run at high spatial resolution (1m cell size) to investigate the effects of projected SLR by 2100 on the wetland communities and to estimate the potential benefits of a proposed NBS project involving the use of dredged sediment to increase wetland surface elevation. Modeling future habitat extent under three SLR scenarios (i.e., intermediate, intermediate-high, and high) with no land modification reveals a consistent pattern of salt marsh expanding into fresh marsh, salt marsh transitioning to higher elevations, and substantially larger overall extents of intertidal and subtidal habitats within the project footprint at relatively high rates of SLR. Simulations that include the NBS indicate changes in the composition of wetland types over time compared with the no-action scenario. Model results help to better understand the long-term behavior of fringing coastal wetlands and the efficacy of their use as part of coastal resilience strategies.

Toward a National Coastal Ecosystem Prediction System: Advancing Marsh Modeling for Sea Level Rise 

We are developing nationally consistent predictions of marsh habitat response to sea level rise (SLR) through a collaborative, multi-agency partnership of modelers and end users. Together, we are co-producing science that directly supports the protection and resilience of coastal ecosystems and infrastructure. Our team is standardizing data and modeling approaches to produce comparable results across regions, making critical information more accessible, usable, and actionable. We aim to empower coastal planners and decision-makers to sustain existing marshes and identify space for future marsh migration as SLR progresses. We are building a unified modeling framework that integrates the leading marsh models into a single coding system. This not only improves transparency and comparability but also sets the stage for expanding the framework to other coastal habitats, such as mangroves and seagrasses. To support this work, we are creating a centralized data library and model platform that allows users to explore model inputs, understand key differences, and apply results confidently to local and regional planning. By working closely with a national community of practice, we ensure that our tools and results reflect real-world needs and the best available science. Together, we are equipping coastal communities with consistent, science-based projections of marsh vulnerability to SLR—helping them plan, adapt, and build resilience for the future.

Computational modeling of coupled waves and vegetation stem dynamics in highly flexible submerged meadows

In this study, we have developed a two-way fully coupled hydrodynamic-vegetation model that includes a spatially and temporally variable drag coefficient of flexible submerged aquatic vegetation (SAV). The developed model consists of a nonhydrostatic wave model (NHWAVE) that solves the Navier-Stokes equations and a numerical model for vegetation stem dynamics that solves the instantaneous forces applied by flow on vegetation stems. The results of the developed model are validated against a number of laboratory-scale experiments on wave attenuation, stem orientation, and stem base forces, and then applied to an idealized configuration to further investigate the effects of vegetation induced drag coefficient on waves velocity field, wave attenuation, and vegetation dynamics along a numerical flume. The model was able to reproduce experimental results without parameter tuning. By adopting the N-pendula approach, the stem dynamics model solves the instantaneous orientation of segments along each stem and uses this information to compute a spatially and temporally varying vegetative drag coefficient within the meadow. When compared with laboratory experiments, incorporating this new mechanism for flexible vegetation in the wave model resulted in improvement over results with rigid vegetation. Through highly detailed representation of vegetation, the model can reliably predict wave attenuation over marshes and seagrass meadows, evaluate potential storm damages to these features, and calculate instantaneous orientation of plant stems or shoots which has implications for their photosynthesis. 

Understanding the Role of Marsh Terraces in Flood Reduction in a Coastal Lagoon under Projected Sea Level Rise 

In the region surrounding Back Bay, coastal flooding occurs repeatedly due to high-water levels, a combination of high tides and wave induced waves. This study investigates flood risk reduction benefits associated with marsh restoration project in Back Bay, VA, which is a relatively shallow coastal lagoon within Back Bay National Wildlife Refuge. To quantify the effects of proposed marsh terraces on water levels, wave heights, and flow velocities within the project area, we developed a high-resolution 2D numerical model to simulate hydro- and morpho- dynamic processes in the system. 

Compound flooding in convergent estuaries: insights from an analytical model

We investigate here the effects of geometric properties (channel depth and cross-sectional convergence length), storm surge characteristics, friction, and river flow on the spatial and temporal variability of compound flooding along an idealized, meso-tidal coastal-plain estuary. An analytical model is developed that includes exponentially convergent geometry, tidal forcing, constant river flow, and a representation of storm surge as a combination of two sinusoidal waves. Nonlinear bed friction is treated using Chebyshev polynomials and trigonometric functions, and a multi-segment approach is used to increase accuracy. Model results show that river discharge increases the damping of surge amplitudes in an estuary, while increasing channel depth has the opposite effect. Sensitivity studies indicate that the impact of river flow on peak water level decreases as channel depth increases, while the influence of tide and surge increases in the landward portion of an estuary. Moreover, model results show less surge damping in deeper configurations and even amplification in some cases, while increased convergence length scale increases damping of surge waves with periods of 12–72 h. For every modeled scenario, there is a point where river discharge effects on water level outweigh tide/surge effects. As a channel is deepened, this cross-over point moves progressively upstream. Thus, channel deepening may alter flood risk spatially along an estuary and reduce the length of a river estuary, within which fluvial flooding is dominant.

The Influence of Channel Deepening on Tides, River Discharge Effects, and Storm Surge 

In this study, we evaluate whether channel deepening and other geometric changes have altered the effects of tides, storm surge, and river flow within the lower Saint Johns River Estuary, Florida, USA. Using data from archives and old reports, we find that tidal range has more than doubled in some locations since the late 1800s. Further, the average water level difference between Jacksonville, Florida and the coast appears to have decreased, while tidal velocities and discharge have increased. Numerical and analytical models show that the primary cause is channel deepening and dredging; other factors, such as shortening the channel, have comparatively minor influence. Using the numerical model, we simulated the effects of hurricane Irma under both modern and historic (1900 Era) geometry. Results show that the storm surge from hurricane Irma was higher today than it would have been a century ago. However, overall water levels in Jacksonville were simulated to be 0.2 m less today than historically, since the deeper channel enabled the record amount of rainfall, runoff, and wind-induced currents from the storm to exit toward the ocean more easily. Hence, anthropogenic development of estuarine waterways can both decrease the hazard from river-based floods, while increasing the marine-sourced hazard.

The effect of channel deepening on tides and storm surge: A case study of Wilmington, NC

In this study we investigate the hypothesis that increasing channel depth in estuaries can amplify both tides and storm surge by developing an idealized numerical model representing the 1888, 1975, and 2015 bathymetric conditions of the Cape Fear River Estuary, NC. Archival tide gauge data recovered from the U.S. National Archives indicates that mean tidal range in Wilmington has doubled to 1.55m since the 1880s, with a much smaller increase of 0.07mobserved near the ocean boundary. These tidal changes are reproduced by simulating channel depths of 7m (1888 condition) and 15.5m (modern condition). Similarly, model sensitivity studies using idealized, parametric tropical cyclones suggest that the storm surge in the worst-case, CAT-5 event may have increased from 3.8 ± 0.25m to 5.6 ± 0.6m since the nineteenth century. The amplification in both tides and storm surge is influenced by reduced hydraulic drag caused by greater mean depths.

Tide‐Storm Surge Interactions in Highly Altered Estuaries: How Channel Deepening Increases Surge Vulnerability 

Many estuaries around the world are heavily altered from their natural state. Wetlands have been reclaimed, and shipping channels widened and deepened to accommodate large container ships. The effects on storm surge and flood risk are just beginning to be explored. In this paper we employ a theoretical approach to understand how the characteristics of a storm surge—such as how fast it is moving, how big it is, and whether it happens on flood or ebb tide—change how it behaves in an estuary. Our results show that storm surge generally gets larger when channels are dredged and deepened; the largest amplification is observed for fast‐moving storms with a short time scale, within estuaries that are highly frictional. Other characteristics—such as the timing relative to the tide and the shape of the estuary—also impact the amplitude and the amount of sensitivity to changing conditions. We find that channel deepening effects are negligible at the coast and far upstream. In between, a region of maximum sensitivity to dredging occurs. Thus, changes in flood risk due to channel deepening and sea level rise can be spatially variable, even within a single estuary.