ERI: Experimental Investigation of Vegetation Effects on Coastal Wave and Current Dynamics

Coastal communities face escalating challenges from rising sea levels and intensifying storms, underlining the urgent need for effective and sustainable shoreline protection strategies. Ecosystems such as mangroves, seagrasses, and wetlands serve as natural barriers against these threats, with mangroves being particularly effective due to their dense and complex root systems. These root structures help dissipate wave energy, slow flood currents, and reduce coastal erosion. However, despite their proven potential, mangroves remain underutilized in engineered coastal defense strategies due to limited understanding of their interaction with hydrodynamic forces. This project aims to address this knowledge gap by experimentally investigating how mangrove root structures influence wave and current dynamics. Advancing this understanding will improve predictive wave models for coastal management and support the integration of mangroves into resilient, nature-based coastal protection strategies. Additionally, this project will provide hands-on research opportunities for students in STEM and engage in community outreach to raise public awareness about nature-based solutions and sustainable coastal resilience.

The primary goal of this project is to investigate the hydrodynamic interactions between mangrove root systems and coastal waves and currents. Specifically, the research will focus on three key objectives: (1) to evaluate how mangrove root morphology influences hydrodynamic processes under various conditions (wave, current, and combined wave-current flows), (2) to examine how currents modify wave dynamics within mangrove environments, and (3) to analyze the turbulence generated by the interaction of waves, currents, and mangrove root structures. Laboratory experiments will use scaled 3D models that closely replicate natural mangrove root morphology. Advanced measurement techniques, including Particle Image Velocimetry (PIV) and Acoustic Doppler Velocimetry (ADV), will be used to measure detailed flow dynamics and turbulence, while direct force measurements will enable precise calculation of drag and inertia coefficients. By addressing the complex and often overlooked interactions between waves, currents, and vegetation, this research will improve the parameterization of vegetation effects in coastal wave models leading to more accurate predictions of wave attenuation and current reduction. The findings of this project will support the integration of nature-based solutions into coastal planning, inform the design of hybrid protection systems that combine natural ecosystems with engineered infrastructure, and promote climate adaptation strategies for more resilient coastal communities.

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: 2502120
Principal Investigator: Che-Wei Chang
Funds Obligated: $200,000
State: RI