Littoral mud flats and shorelines: soil-sea-ice-air and benthic life interactions

The overarching goal of this project is to develop a fundamental and comprehensive understanding of the geomechanics of littoral mud flats and shorelines towards reliable prediction of geomorphodynamics, trafficability, and navigation from satellite images and geoacoustic surveying. This 5-year study aims to:

1. Determine what environmental processes and feedbacks control the geomechanics of littoral mud flats and shorelines.
2. Measure these processes and feedbacks conjointly with geotechnical site characterization and satellite-based remote sensing;
3. Assess if climatic regimes affect and possibly change which processes and feedbacks are dominant.
4. Develop and validate a global mud flat classification framework.
5. Determine which satellite products would be most efficient for deriving the tidal flat geomechanical properties. This will be achieved through literature and data review, field and laboratory testing, cross-disciplinary fusion and data analysis.

Research will include detailed multi-disciplinary field investigations of five sites located in distinct geographic regions and environments, laboratory analysis of samples, data analyses, cross-disciplinary data fusion, and validation at new field sites.

Sponsor: Office of Naval Research (ONR, www.onr.navy.mil)

Team members:

• Nina Stark (PI, University of Florida)
• Kelly Dorgan (co-PI, University of Texas)
• Emily Eidam (co-PI, Oregon State University)
• Sungyoon Jung (co-PI, University of Florida)
• Julie Paprocki (co-PI, University of New Hampshire)
• Zhaohui Yang (co-PI, University of Alaska)

Geotechnical risk assessment and mitigation strategies of dune toe collapse and dune erosion

Florida Sea Grant Graduate Fellowship for Saurav Shrestha

The impact of geotechnical properties on seabed crawler mobility in coastal environments

Sponsor: U.S. Army Corps of Engineers

Littoral Mud Flats and Shorelines: Soil-Sea-Ice-Air and Benthic Life Interactions

Sponsor: Office of Naval Research (ONR, www.onr.navy.mil)

Integration of soil mechanics in numerical models of surf zone beach processes

Sponsor: Office of Naval Research (ONR, www.onr.navy.mil)

Towards an integrative understanding of near-surface seabed structure

Sponsor: Office of Naval Research (ONR, www.onr.navy.mil)

RAPID: Quantification of Sediment Erosion and Deposition, Debris Accumulation, and associated Damages to the Built Environment from Storm Surge and Wave Action during Hurricane Helene

Sponsor: National Science Foundation

ModPen: Modular Free Fall Penetrometer System for Seabed Sediment Testing

Sponsor: Office of Naval Research (ONR, www.onr.navy.mil)

Rapid soil classification and integration of soil characteristics for UXO site characterization and risk assessment

The overarching goal of project is to investigate the interactions between geotechnical seabed soil properties and behavior, physical sediment dynamics, and benthic biogenic processes towards the rapid geotechnical site characterization of seabed sediments using portable free fall penetrometer for enhancement of acoustic seabed site classification, assessment of UXO mobility and remediation needs, and generally UXO risk assessment. The research objectives are to: i) develop a soil behavior classification scheme based on portable free fall penetrometer measurements; ii)  identify effects of benthic biogenic processes on geotechnical soil properties and integrate these effects in the soil classification scheme; iii) identify and quantify the impacts of the different soil classes on acoustic UXO detection and classification methods, on erodibility estimates, and on susceptibility to soil liquefaction processes; and iv) develop strategies to implement the effects of soil classes into UXO risk assessment.

Sponsor: Strategic Environmental Research and Development Program (SERDP, Home (serdp-estcp.org)), grant MR21-C1-1265

Team members:

• Nina Stark (PI, University of Florida)
• Adrian Rodriguez-Marek (PI) and Md Rejwanur Rahman (PhD student) (both Virginia Tech)
• Grace Massey (PI) and Carl Friedrichs (PI) (both Virginia Institute of Marine Sciences)
• Kelly Dorgan (PI) and Chesna Cox (MS student) (both Dauphin Island Sea Lab)

Assessment of trafficability of coastal sediments from satellite based remote sensing

Insufficient trafficability of coastal soils represents a major uncertainty and risk to naval missions, as well as for rescue and evacuation missions in coastal environments. In most cases, on-site physical testing and in-situ determination of geotechnical properties that enable an assessment of trafficability is unfeasible due to access or timing restrictions. Thus, the long-term goal of this work is to develop relationships between geotechnical properties of coastal sediments, satellite-based remotely sensed data, and coastal processes to predict trafficability for a variety of vehicles with high confidence.

Towards this long-term goal, the objectives of the proposed study are:

1. Detect and map coastal sediment dynamics in the intertidal zone from satellite images and relate them to geotechnical properties – and the variability thereof – relevant for the assessment of trafficability, including fines content, water content, relative density, and bearing capacity.
2. Develop probability thresholds predicting the trafficability of a person, a wheeled vehicle, and a hovercraft for a wide range of typical coastal sediments and geotechnical characteristics. Apply probability thresholds to trafficability assessment based on geotechnical properties derived from satellite imagery and assess uncertainty.

Sponsor: Office of Naval Research (ONR, www.onr.navy.mil), N00014-23-1-2418

Team Members:

• Nina Stark (PI) and Stephen Adusei (PhD student) (both University of Florida)
• Fred Falcone (PhD student, Virginia Tech)
• Julie Paprocki (PI, University of New Hampshire)

Integration of soil mechanics in numerical models of surf zone beach processes via joint field observation and numerical modelling

The longterm goal is to predict rapid beach evolution and the associated variations in seabed soil strength and textural seabed properties due to storms by integrating soil mechanics into regional-scale morphodynamic models with the aim of assisting with model calibrations for acoustic surveying and navigation, as well as with trafficability assessment from remote sensing.

To achieve the longterm goal, the research aims at understanding the relationship between local geomorphodynamics and geotechnical properties of the seabed and intertidal zone sediment surface layers by collecting, analyzing, and correlating field data, and improving numerical modeling tools with the following objectives:

1. Analyzing and preparing existing field data of geotechnical properties for numerical model validation.
2. Performing new field experiments supported by laboratory soil characterization specifically designed to advance fine-scale and regional scale models’ soil mechanics capability.
3. Evaluate the sensitivity of the short-wave-averaged regional-scale morphodynamic model XBeach for various parameterizations relevant to sediment transport and erodibility.
4. Improving and validating the free-surface resolving Eulerian two-phase modeling framework, SedFoam, for simulating sediment transport under waves with proper geotechnical seabed properties to improve erodibility related sub-models in XBeach.
5. Assess and evaluate the relationship between geotechnical properties and local geomorphodynamics in the surf zone during storm events via a synthesis of observational data, fine-scale and regional-scale model data.

Sponsor: Office of Naval Research (ONR, www.onr.navy.mil), N00014-22-1-2398

Team Members:

• Nina Stark (PI) and Saurav Shrestha (PhD student) (both University of Florida)
• Tom Hsu (PI) and Jiaye Zhang (PhD student) (both University of Delaware)
• Adrian Rodriguez-Marek (PI, Virginia Tech)
• Patrick Dickhudt (U.S. Army Corps of Engineers)
• Jonathan Hubler (Villanova University)