Physical Sciences and Mathematics Commons^™

Northern Neck Regional Shallow Draft Channel Dredging Plan: Feasibility Phase, Donna A. Milligan, Cameron W. Green, C. Scott Hardaway Jr., Christine A. Wilcox, Claire M. Rae, Scott Lerberg, Alex Demeo, George Brooks, Mark Mansfield

Reports

The Initial Phase of the project (Phase 1), used remote sensing and other data collection to develop a method for determining which waterbodies on the Northern Neck of Virginia need dredging. The analysis included most of the waterbodies in the counties of Lancaster, Northumberland, Richmond, and Westmoreland. From this analysis, 19 waterbodies emerged as potentially needing dredged based on physical parameters and residential and economic usage (Milligan et al., 2023).

In this Feasibility Phase (Phase 2), more detailed site data were collected to provide data to the localities for consideration. These tasks were included in the analysis:

1. Historic shore …

Northern Neck Regional Shallow Draft Channel Dredging Plan: Initial Phase, Donna A. Milligan, Grace M. Massey, C. Scott Hardaway Jr., Christine A. Wilcox, Cameron W. Green, Mark Mansfield

Reports

The purpose of this project is to develop a regional dredging program for the localities of the Northern Neck. This report encompasses Phase 1 of the project, which included creating a database of waterbodies in Lancaster, Northumberland, Richmond, and Westmoreland Counties and the Town of Colonial Beach along the Potomac and Rappahannock Rivers and Chesapeake Bay. Generally, these waterbodies can be categorized into three basic types of shallow draft channels: federally-authorized to include aids to navigation (ATONS), non-federal with ATONS, and non-federal without ATONs. Along the Northern Neck, presently identified, are 13 federal channels, 37 non-federal channels in creeks with …

Sediment And Terrestrial Organic Carbon Budgets For The Offshore Ayeyarwady Delta, Myanmar: Establishing A Baseline For Future Change, Evan R. Flynn, S. Kuehl, Courtney K. Harris, Matthew J. Fair

VIMS Articles

Large river deltas serve as globally important archives of terrestrial and shallow marine biogeochemical signatures and because of rapid sedimentation have the potential to impact global biogeochemical cycling. The Ayeyarwady Delta in Myanmar ranks as the world's third largest river delta in terms of sediment supply; however, modern increases in regional anthropogenic impacts risk severe alteration to sediment and TerrOC loads within this major system. By investigating modern sediment and terrestrial organic carbon (TerrOC) accumulation within the offshore Ayeyarwady Delta this study estimates baseline sediment and TerrOC budgets for this understudied mega-delta. Using 210Pb geochronology of 27 sediment cores collected …

Benthic Biofilm Potential For Organic Carbon Accumulation In Salt Marsh Sediments, Kendall Valentine, Abbey Hotard, Tracy Elsey-Quirk, Giulio Mariotti

VIMS Articles

Coastal salt marshes are productive environments with high potential for carbon accumulation and storage. Even though organic carbon in salt marsh sediment is typically attributed to plant biomass, it can also be produced by benthic photosynthetic biofilms. These biofilms, generally composed of diatoms and their secretions, are known for their high primary productivity and contribution to the basal food web. The growth of biofilms and the preservation of carbon produced by biofilms depends on the amount of sedimentation; low sedimentation rates will favor decomposition, while high sedimentation rates could decrease biofilm productivity. In this study, we conducted laboratory experiments to …

Measuring Organization Of Large Surficial Clasts In Heterogeneous Gravel Beach Sediments, Dennis C. Lees, Christopher J. Hein, Duncan M. Fitzgerald

VIMS Articles

The natural stratification and interlocking “organization” of armored sediments in heterogeneous, coarse-grained, beaches provides protection and enhances habitat for borrowing sedentary megafauna and macrofauna such as hard-shelled clams. Here, we develop a novel metric for quantifying sediment organization of large surficial beach clasts through sedimentologic and photogrammetric analyses of 37 lower intertidal heterogeneous gravel beaches in western Prince William Sound, Alaska (USA). Grain size, photogrammetric, and Wolman Pebble Count clast-size data from 64, ~1-m² study plots are combined into a clast-size-independent “Organization Metric” to quantify the degree of organization in the meshed arrangement of larger surficial sediments. This metric …

Effects Of Shell Hash On Friction Angles Of Surficial Seafloor Sediments Near Oysters, Samuel T. Consolvo, Nina Stark, (...), Grace M. Massey

VIMS Articles

Oysters are hypothesized to affect the shear strength of nearby surficial seafloor sediment as fragments of oyster shells (shell hash) are typically more angular relative to sand particles alone, among other differences. Resistance to shearing is well characterized by the friction angle, which is estimated in this study from vacuum triaxial laboratory and portable free-fall penetrometer field tests. Friction angles of sediment with shell hash were higher relative to those of sediment without shell hash (via hydrochloric acid treatment) on average by about 19% (36.0°–30.2°, respectively). Triaxial confining pressures ranged between 2.1 and 49.0 kPa to simulate subtidal and intertidal …

Three Centuries Of Vegetation Change In The William & Mary College Woods Reconstructed Using Phytoliths, Timothy Terlizzi

Undergraduate Honors Theses

The College Woods, west of William & Mary’s campus, consists of ~900 acres of protected southern mixed hardwood forest. The woods surround Lake Matoaka, a former millpond established in ~1700. Despite the rich history of the area, little is known about how the dominant vegetative landcover has shifted over the last 300 years. This study set out to quantify the modern vegetation within the College Woods via the phytolith assemblages within the soil and identify shifts in the assemblages since the creation of Lake Matoaka and whether these changes are distinct from the vegetation that existed in the area before …

The Geomorphic Impact Of Mangrove Encroachment In An Australian Salt Marsh, Daniel J. Coleman, Kerrylee Rogers, D. Reide Corbett, Christopher J. Owers, Matthew L. Kirwan

VIMS Articles

Mangroves are encroaching into salt marshes throughout the world as a result of environmental change. Previous studies suggest mangroves trap sediment more efficiently than adjacent salt marshes, providing mangroves greater capacity to adapt to sea level rise; this may occur by displacing salt marshes. However, sediment transport in adjacent marsh-mangrove systems and its role in mangrove encroachment upon salt marsh remain poorly understood. Here we directly test the hypothesis that mangroves reduce the ability of adjacent marsh to adjust to sea level rise by measuring sediment transport across salt marsh platforms, with and without 6 m of fringing mangroves at …

The Effect Of Coastal Landform Development On Decadal- To Millennial-Scale Longshore Sediment Fluxes: Evidence From The Holocene Evolution Of The Central Mid-Atlantic Coast, Usa - Sediment Core And Chronology Data, Justin L. Shawler, Christopher J. Hein, Chloe Obara, Mahina Robbins, Jennifer E. Connell, Sebastien Huot, Michael Fenster

Data

These data are sediment core, radiocarbon, and optically stimulated luminescence (OSL) data from the barrier islands and backbarrier lagoons, bays, and marshes of Assateague Island (VA, USA), Chincoteague Island (VA, USA), and Wallops Island (VA, USA). Vibracore data from Tom’s Cove, a backbarrier bay, were collected using a vibracore system with the ability to core through a ‘moonhole’ on a flat bottom boat. Geoprobe cores were collected using a track-mounted 66DT Geoprobe direct-push drill rig. Select samples from the sediment cores (associated with figures and tables in Shawler et al., 2021) were analyzed using a Beckman-Coulter Laser Diffraction Particle Size …

Supporting Data: Controls On Sediment Bed Erodibility In A Muddy, Partially-Mixed Tidal Estuary, York River, Virginia, Cristin L. Wright, Grace M. Massey, Patrick J. Dickhudt, Carl T. Friedrichs

Data

Dataset consists of all sampling cruises with data that were analyzed and used in the statistical modeling associated with Wright (2021) and Wright et al. (2022). Each cruise folder includes erodibility data that was analyzed using a Gust Microcosm along with sediment and water column characteristics.

The Effect Of Coastal Landform Development On Decadal-To Millennial-Scale Longshore Sediment Fluxes: Evidence From The Holocene Evolution Of The Central Mid-Atlantic Coast, Usa, Justin L. Shawler, Christopher J. Hein, Chloe A. Obara, Mahina G. Robbins, Sebastien Huot, Michael S. Fenster

VIMS Articles

The behavior of siliciclastic coastal systems is largely controlled by the interplay between accommodation creation and infilling. Factors responsible for altering sediment fluxes to and along open-ocean coasts include cross-shore mobilization of sediment primarily from tidal currents and storms as well as changes in alongshore transport rates moderated by changing wave conditions, river sediment inputs, artificial shoreline hardening and modification, and natural sediment trapping in updrift coastal landforms. This paper focuses on the latter relationships. To address understudied interactions between updrift coastal landforms and downdrift coastal behavior, we quantify the volume and fluxes of sediment trapped in the Assateague-Chincoteague-Wallops barrier-island …

Coastal Marsh Degradation Into Ponds Induces Irreversible Elevation Loss Relative To Sea Level In A Microtidal System, Lennert Schepers, Patrick Brennand, Matthew L. Kirwan, Glenn Guntenspergen, Stijn Temmerman

VIMS Articles

Coastal marshes and their valuable ecosystem services are feared to be lost by sea level rise, yet the mechanisms of marsh degradation into ponds and potential recovery are poorly understood. We quantified and analyzed elevations of marsh surfaces and pond bottoms along a marsh loss gradient (Blackwater River, Maryland, USA). Our analyses show that ponds deepen with increasing tidal channel width connecting the ponds to the river, indicating a new feedback mechanism where channels lead to enhanced tidal export of pond bottom material. Pond elevations also decrease with increasing pond size, consistent with previous work identifying a positive feedback between …

Relative Influence Of Antecedent Topography And Sea-Level Rise On Barrier-Island Migration: Sediment Core Data, Justin L. Shawler, Jennifer E. Connell, Bianca Q. Boggs, Christopher J. Hein

Data

No abstract provided.

Sediment Delivery To A Tidal Marsh Platform Is Minimized By Source Decoupling And Flux Convergence, Daniel J. Coleman, Neil K. Ganju, Matthew L. Kirwan

VIMS Articles

Sediment supply is a primary factor in determining marsh response to sea level rise and is typically approximated through high‐resolution measurements of suspended sediment concentrations (SSCs) from adjacent tidal channels. However, understanding sediment transport across the marsh itself remains limited by discontinuous measurements of SSC over individual tidal cycles. Here, we use an array of optical turbidity sensors to build a long‐term, continuous record of SSC across a marsh platform and adjacent tidal channel. We find that channel and marsh concentrations are correlated (i.e., coupled) within tidal cycles but are largely decoupled over longer time scales. We also find that …

Vims 2019 York River Estuary Data In Support Of: Improved Penetrometer Performance In Stratified Sediment For Cost-Effective Characterization, Monitoring And Management Of Submerged Munitions Sites (Serdp Project: Mr18-1233), Grace M. Massey, Cristin L. Wright, Carl T. Friedrichs, Nina Stark, Dennis Kiptoo

Data

This work complements the efforts by the Virginia Tech Department of Civil & Environmental Engineering in SERDP MR18-1233, as described in the project’s final report (Stark et al, 2020) and in the Master’s thesis by Dennis Kiptoo (Kiptoo, 2020). One of the objectives of the project was to improve calibration of the Bluedrop free fall penetrometer (FFP) with high resolution sampling of a variety of sediment types. To accomplish this, a series of 9 stations over 12 cruises were visited along the York River, an estuary in the Virginia portion of the Chesapeake Bay, and in the Pamunkey River, which …

Vims 2019 Potomac River Estuary Data In Support Of: Improved Penetrometer Performance In Stratified Sediment For Cost-Effective Characterization, Monitoring And Management Of Submerged Munitions Sites (Serdp Project: Mr18-1233), Grace M. Massey, Cristin L. Wright, Carl T. Friedrichs, Nina Stark, Dennis Kiptoo

Data

This work complements the efforts by the Virginia Tech Department of Civil & Environmental Engineering in SERDP MR18-1233, as described in the project’s final report (Stark et al, 2020) and in the Master’s thesis by Dennis Kiptoo (Kiptoo, 2020). Previous work on this project, conducted in the York River during 2018-2918 worked to improve calibration of the Bluedrop free fall penetrometer (FFP) with high resolution sampling of a variety of sediment types (Massey et al, 2020a). Calibration methods developed (Kiptoo, 2020) were used to rapidly identify different sediment types from a grid of 59 Bluedrop PPF stations sampled on the …

Impacts Of Seagrass Dynamics On The Coupled Long‐Term Evolution Of Barrier‐Marsh‐Bay Systems, I.R.B. Reeves, L. J. Moore, E. B. Goldstein, A. B. Murray, Matthew L. Kirwan

VIMS Articles

Seagrass provides a wide range of economically and ecologically valuable ecosystem services, with shoreline erosion control often listed as a key service, but can also alter the sediment dynamics and waves within back‐barrier bays. Here we incorporate seagrass dynamics into an existing barrier‐marsh exploratory model, GEOMBEST++, to examine the coupled interactions of the back‐barrier bay with both adjacent (marsh) and nonadjacent (barrier island) subsystems. While seagrass reduces marsh edge erosion rates and increases progradation rates in many of our 288 model simulations, seagrass surprisingly increases marsh edge erosion rates when sediment export from the back‐barrier basin is negligible because the …

Role Of Delta-Front Erosion In Sustaining Salt Marshes Under Sea-Level Rise And Fluvial Sediment Decline, Shi Lun Yang, Xiangxin Luo, Stijn Temmerman, Matthew L. Kirwan, Et Al

VIMS Articles

Accelerating sea-level rise and decreasing riverine sediment supply are widely considered to lead to global losses of deltaic marshes and their valuable ecosystem services. However, little is known about the degree to which the related erosion of the seaward delta front can provide sediments to sustain salt marshes. Here, we present dataf rom the mesomacrotidal Yangtze Delta demonstrating that marshes have continued to accrete vertically and laterally, despite rapid relative sea-level rise (approx.10 mm yr−1) and a > 70% decrease in the Yangtze River sediment supply. Marsh progradation has decelerated at a lower rate than fluvial sediment reduction, suggesting an additional …

Impacts Of Muddy Bed Aggregates On Sediment Transport And Management In The Tidal James River, Va, David W. Perkey, S. Jarrell Smith, Kelsey A. Fall, Grace M. Massey, Carl T. Friedrichs, Emmalynn M. Hicks

VIMS Articles

Aggregation state significantly influences the size, density and transport characteristics of fine sediment. Understanding sediment transport and deposition processes in the nation’s navigable waterways is a primary mission for the US Army Corps of Engineers (USACE), particularly when it comes to infilling of navigation channels. In this study, a newly developed camera system was used to evaluate the aggregation state of eroded sediment from cores collected in the tidal James River, VA. Results showed that bed sediments were composed mostly of mud, but that erosion predominately occurred in the form of aggregates with median sizes 50-270x larger than the disaggregated …

Tidal Erosion And Upstream Sediment Trapping Modulate Records Of Land-Use Change In A Formerly Glaciated New England Estuary, Justin L. Shawler, Christopher J. Hein, Elizabeth A. Canuel, Et Al

VIMS Articles

Land clearing, river impoundments, and other human modifications to theupland landscape and within estuarine systems can drive coastal change at local to regionalscales. However, as compared with mid-latitude coasts, the impacts of human modificationsalong sediment-starved formerly glaciated coastal landscapes are relatively understudied.To address this gap, we present a late-Holocene record of changing sediment accumulationrates and sediment sources from sediment cores collected across a tidal flat in theMerrimack River estuary (Mass., USA). We pairsedimentology, geochronology, bulk- andstable-isotope organic geochemistry, and hydrodynamic simulations with historical datato evaluate human and natural impacts on coastal sediment fluxes. During the 17th to19th centuries, accumulation rates …

Rural Shallow Water Dredging: Channel Assessment And Disposal Site Strategies, C. Scott Hardaway Jr., Donna A. Milligan, Christine A. Wilcox

Reports

The goal of this report is to provide general considerations for localities on the dredging and disposal of material from shallow draft channels, in particular for those channels on the Middle Peninsula, Northern Neck, and Eastern Shore of Virginia (Figure 1-1). This report offers background on shallow draft channels, both federally and non-federally maintained, suggests procedures for the dredging and disposal process, and applies the process to an existing channel. Existing data on the Middle Peninsula, Northern Neck, and Eastern Shore channels are provided to assist localities with management decisions. In addition to data for most of the existing federal …

Incorporating Sea Level Change Scenarios Into Norfolk Harbor Channels Deepening And Elizabeth River Southern Branch Navigation Improvements Study : Final Report On The “Hydrodynamic Modeling”, Zhuo Liu, Harry V. Wang, Yinglong J. Zhang, Fei Ye

Reports

The Virginia Institute of Marine Science (VIMS) team has applied a 3D unstructured-grid hydrodynamic model SCHISM in the study of the impact of channel dredging on hydrodynamics in the lower Chesapeake Bay project area. This report is a companion report to that of Zhang et al. (2017; doi:10.21220/V5MF0F) and focuses on the impact of channel dredging specifically under the projected future sea-level change (SLC) of 1 meter rise by 2100. This is an average of the high end of semi-empirical, global sea-level rise (SLR) projections adopted by the Virginia Port Authority (VPA) and the Army Corps of Engineers, Norfolk District, …

Assessment Of Hydrodynamic And Water Quality Impacts For Channel Deepening In The Thimble Shoals, Norfolk Harbor, And Elizabeth River Channels : Final Report On The “Hydrodynamic Modeling”, Yinglong J. Zhang, Harry V. Wang, Fei Ye, Zhengui Wang

Reports

For over twenty years, the U. S. Army Corps of Engineers (USACE) and the Virginia Port Authority (VPA), representing the Commonwealth Secretary of Transportation, have collaborated on projects key to port development that also preserve the environmental integrity of both Hampton Roads and the Elizabeth River. The USACE and the VPA are working to investigate channel deepening in this region to provide access to a new generation of cargo ships (e.g., Panamax-class). The main goal of this project is to investigate the feasibility for Norfolk Harbor channel deepening in the lower James and Elizabeth Rivers and assess the environmental impact …

Assessment Of Hydrodynamic And Water Quality Impacts For Channel Deepening In The Thimble Shoals, Norfolk Harbor, And Elizabeth River Channels, Jian Shen, Rico Wang, Mac Sisson

Reports

To investigate the feasibility for Norfolk Harbor channel deepening in the lower James and Elizabeth Rivers, one of the key services of the project is to evaluate the impacts of deepening the Atlantic Ocean Channel to 55 feet (from 50 feet), Thimble Shoal Channel to 55 feet (from 50 feet), Elizabeth River (north of Lambert Point) to 50 feet (from 45 feet) and the Southern Branch (north of the I64 Bridge) to 50/45/45 feet. In general, the shipping channel dredging will result in enhancement of estuarine gravitational circulation, accentuate the tidal and wind wave influence upstream, and affect the ecosystem …

Incorporation Of Sea Level Change Scenarios Into Norfolk Harbor And Channels Deepening Study & Elizabeth River Southern Branch Navigation Improvements Study : Final Report, Rico Wang, Jian Shen, Mac Sisson

Reports

Previously the VIMS modeling group has studied the impact of channel deepening on the water quality in lower James River, including Norfolk Harbor and Elizabeth River. A study of the response of the water quality to future Sea Level Change (SLC) is required by present USACE guidance (ER 1100-2-8162 and ETL 1100-2-1). ETL 1100-2-1 recommends analyzing the effects of SLC on the projects at three future time periods of post-construction, including 20 years, 50 years, and 100 years. The future change of sea level is mainly caused by the sea level rise (SLR) in this region. This document provides results …

A Model Archive For A Coupled Hydrodynamic-Sediment Transport-Biogeochemistry Model For The Rhône River Sub-Aqueous Delta, France, Julia Moriarty, Courtney K. Harris, Katja Fennel, Kehui Xu, Christophe Rabouille, Marjorie A.M. Friedrichs

Data

This dataset includes model input, code, and output used in the publication Moriarty et al. (2017, Biogeosciences), which used a coupled hydrodynamic-sediment transport-biogeochemical model to investigate the roles of resuspension, diffusion and biogeochemical processes on oxygen dynamics on the Rhône River sub-aqueous delta, France. Model development for this project focused on coupling the sediment transport and water-column biogeochemistry modules in the Regional Ocean Modeling System (ROMS) by incorporating a seabed biogeochemistry module into the ROMS framework. As described in Moriarty et al. (2017, Biogeosciences), the coupled model can account for diffusion of nutrients across the seabed-water-column interface; storage …

2016 Data Collected For Resistivity, Magnetic Susceptibility And Sediment Characterization Of The York River Estuary, Va In Support Of The Empirical Investigation Of The Factors Influencing Marine Applications Of Emi (Year 2 Of Serdp Project Mr-2409), Grace M. Massey, Carl T. Friedrichs

Data

The objective of this component of the Strategic Environmental Research and Development Program (SERDP) Project MR-2409 was to conduct field measurements to aid in the determination of the electromagnetic induction (EMI) response to the water column and underlying sediments in the York River estuary, which includes water column and sediment properties similar to many underwater environments of interest to unexploded ordinance detection. Data and samples from a standard suite of hydrographic and sedimentological measurements, as well as electrical resistivity and magnetic susceptibility, were collected and analyzed for each location. These cruises provided opportunities to obtain information that is being used …

Hampton Roads Crossing Study Supplemental Environmental Impact Statement: Evaluation Of Potential Impact On Surface Water Elevation, Flow, Salinity, And Bottom Shear Stress, Yinglong J. Zhang, Harry V. Wang, Zhuo Liu, Mac Sisson, Jian Shen

Reports

The purpose of this study is to evaluate the potential impacts of the proposed alternatives for the highway crossing in Hampton Roads on physical characteristics of surface water elevation, flow, salinity, and bottom shear stress. The analysis is part of the Virginia Department of Transportation (VDOT), the Federal Highway Administration, and other stakeholders’ Supplemental Environmental Impact Statement (SEIS) for Hampton Roads Crossing Study (HRCS).

Resistivity, Magnetic Susceptibility And Sediment Characterization Of The York River Estuary In Support Of The Empirical Investigation Of The Factors Influencing Marine Applications Of Emi (Year 2 Of Serdp Project Mr-2409) Final Report., Grace M. Massey, Carl T. Friedrichs

Reports

Vessel and personnel support was provided for a series of cruises to three salinity regimes along the York River. Data and samples from a standard suite of hydrographic and sedimentological measurements, as well as electrical resistivity and magnetic susceptibility, were collected and analyzed for each location. These cruises provided opportunities to obtain information that is being used to quantify the unique marine contributions to the early time TEM noise, including conductivity variations in the water and variability in bottom sediment properties in real marine environments, for use in the parallel modeling and electromagnetic-induction sensor work ongoing in the same project. …

Evaluation Of The Potential Impact On Flow And Sediment Transport From Proposed James River Crossings, Yinglong J. Zhang, Harry V. Wang, Zhuo Liu, Mac Sisson, Jian Shen

Reports

The purpose of this study is to evaluate the potential impact on flow and sedimentation potential due to the proposed new crossings on the lower James River by VDOT. This project was built upon previous effort in the same area (Boon et al. 1999); the latter used VIMS’ 3D Hydrodynamic-Sedimentation Model (HYSED) to study the impact of the bridge-tunnel infrastructure on the physical characteristics (including tides, currents, circulation, salinity and sedimentation) under the existing and alternative scenarios. Due to various limitations at that time, smaller bridge pilings were not resolved but instead parameterized. In this update study, we used an …