18 Sep 2023

A Resilient Path Forward for the Marine Transportation System: Recommendations for Response and Recovery Operations from the 2017-2019 Hurricane Seasons

Abstract: The Marine Transportation System (MTS), Resilience Integrated Action Team (RIAT), is tasked by the coordinating board of the US Committee on the MTS to serve as a coordinating body to identify the impacts, best practices, and lessons learned by federal agencies involved in the response and recovery of the MTS after hurricane seasons. In response to this request, the RIAT has focused its analysis on the ability of MTS federal agencies to prepare, respond, recover, and adapt to as well as from disruptions. This was accomplished through workshops focused on gathering the collective experiences of emergency response professionals. In 2017, recommendations were gathered based on experiences responding to Hurricanes Harvey, Irma, and Maria. In this report, a similar approach was adopted to gather findings from Hurricanes Florence and Michael in 2018 and Hurricane Dorian in 2019. Utilizing the successes, challenges, and best practices from all six of these storms, the RIAT identified key coordinating bodies and the participants for each and key takeaways relative to the coordination of agencies with respect to the four steps of resilience: prepare, absorb, recover, and adapt.

15 Sep 2023

Real-Time Forecasting Model Development Work Plan

Abstract: The objective of the Lowermost Mississippi River Management Program is to move the nation toward more holistic management of the lower reaches of the Mississippi River through the development and use of a science-based decision-making framework. There has been substantial investment in the last decade to develop multidimensional numerical models to evaluate the Lowermost Mississippi River (LMMR) hydrodynamics, sediment transport, and salinity dynamics. The focus of this work plan is to leverage the existing scientific knowledge and models to improve holistic management of the LMMR. Specifically, this work plan proposes the development of a real-time forecasting (RTF) system for water, sediment, and selected nutrients in the LMMR. The RTF system will help inform and guide the decision-making process for operating flood-control and sediment-diversion structures. This work plan describes the primary components of the RTF system and their interactions. The work plan includes descriptions of the existing tools and numerical models that could be leveraged to develop this system together with a brief inventory of existing real-time data that could be used to validate the RTF system. A description of the tasks that would be required to develop and set up the RTF system is included together with an associated timeline.

14 Sep 2023

Surge Analysis in Mobile Harbor, Alabama: Ship-Simulation Report

Abstract: A navigation channel improvement study for Mobile Harbor was conducted by the US Army Corps of Engineers, Mobile District (CESAM), and the Alabama State Port Authority. The US Army Engineer Research and Development Center (ERDC) assisted CESAM in assessing channel modifications using ERDC’s Ship/Tow Simulator through a Feasibility Level Screening Simulation study in 2017 and through a more comprehensive ship-simulation study in 2020. During the 2020 study, a safety concern was identified related to vessel interactions between a transiting vessel passing docked vessels at the McDuffie Coal Terminal located along the main federal channel. In the previous ship-simulation studies, the docked vessels were represented as targets, which means the ships are visually represented but no hydrodynamic interaction is captured. To fully assess this interaction, a surge-analysis study was completed in 2022 that used hydrodynamic models to represent docked vessels with representative mooring conditions. This study assessed several proposed navigation channel expansions across from the McDuffie Coal Terminal over the course of six testing days with four pilots. Assessment of the proposed modifications was accomplished through analysis of ship simulations completed by experienced local pilots, track plots, run sheets, and final pilot questionnaires.

13 Sep 2023

Sensitivity of Sediment Transport Analyses in Dam Removal Applications

Abstract: Dam removal has become a widespread river management practice in the US for a variety of goals including ecosystem restoration, removing aging infrastructure, flood risk management, and recreation. The ability to forecast the sediment impacts of dam removal is critical to evaluating different management alternatives that can minimize adverse consequences for ecosystems and human communities. Tullos et al. (2016) identified seven Common Management Concerns (CMCs) associated with dam removal. Four of these CMCs; degree and rate of reservoir sediment erosion, excessive channel incision upstream of reservoirs, downstream sediment aggradation, and elevated downstream turbidity are associated with stored sediment release and changing fluvial hydraulics. There are a range of existing qualitative and quantitative tools developed to infer or quantify geomorphic implications of disturbances like these in river environments (McKay et al. 2019). This study investigated how a one-dimensional (1D) sediment transport model can inform these four CMCs, develop an approach for assessing sediment transport model sensitivity in the context of the Simkins Dam removal, and use sensitivity analyses to identify key uncertainties, which can inform data collection and model building for other dam removal projects. For the selected case study, model outputs including the mean effective invert change (MEIC) and eroded sediment volume from reservoir were highly sensitive to the variation of the reservoir sediment gradation and sorting method selection. These model outputs also showed some sensitivity to the selected transport functions. Erosion method sensitivity using the channel evolution method will vary depending on side slope and channel parameter selection.

8 Sep 2023

Applicability of CoastSnap, a Crowd-Sourced Coastal Monitoring Approach for US Army Corps of Engineers District Use

Abstract: This US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, technical report details the pilot deployment, accuracy evaluation, and best practices of the citizen-science, coastal-image monitoring program CoastSnap. Despite the need for regular observational data, many coastlines are monitored infrequently due to cost and personnel, and this cell phone-image-based approach represents a new potential data source to districts in addition to providing an outreach opportunity for the public. Requiring minimal hardware and signage, the system is simple to install but requires user-image processing. Analysis shows the CoastSnap-derived shorelines compare well to real-time kinematic and lidar-derived shorelines during low-to-moderate wave conditions (root mean square errors [RMSEs] <10 m). During high-wave conditions, errors are higher (RMSE up to 18 m) but are improved when incorporating wave run-up. Beyond shoreline quantification, images provide other qualitative information such as storm-impact characteristics and timing of the formation of beach scarps. Ultimately, the citizen-science tool is a viable low-cost option to districts for monitoring shorelines and tracking the evolution of coastal projects such as beach nourishments.

5 Sep 2023

Proceedings from the US Army Corps of Engineers (USACE) 2021 Beneficial Use of Dredged Material Virtual Workshop

Abstract: On 13–15 July 2021, 58 representatives from Headquarters, US Army Corps of Engineers (USACE), 2 USACE Divisions, 14 USACE districts, and US Army Engineer Research and Development Center’s (ERDC) Environmental (EL) and Coastal Hydraulics (CHL) Laboratories came together and participated in a virtual workshop on the beneficial use (BU) of dredged material. The overall goal was to organize the BU community across USACE and develop a path forward to increase BU practices. Talks and discussions focused on the current status of BU across USACE, including success stories on innovative BU projects, challenges related to regulatory issues, state and federal policies, technical logistics, and stakeholder engagement, as well opportunities for expanding current practices to include more regular and innovative applications. The workshop was cohosted by Dr. Amanda Tritinger (CHL) and Dr. Kelsey Fall (CHL) on behalf of the Engineering With Nature®, Coastal Inlets Research Program, Dredging Operations and Environmental Research, and Regional Sediment Management research programs. The workshop concluded by introducing and awarding the first annual Timothy L. Welp Award for Advancing Beneficial Use of Dredged Sediments to recognize teams (with members across and outside of USACE) that have advanced progress on BU through collaboration, partnering, and innovation.

24 Aug 2023

Houston Ship Channel Numerical Model Update and Validation

Abstract: The Houston Ship Channel (HSC) is one of the busiest deep-draft navigation channels in the United States and must be able to accommodate increasing vessel sizes. The US Army Corps of Engineers, Galveston District (SWG), requested the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, update and revalidate a previously developed three-dimensional Adaptive Hydraulics (AdH) hydrodynamic and sediment model of the HSC, Galveston, and Trinity Bays. The model is necessary for analyzing potential impacts on salinity, sediment, and hydrodynamics due to alternatives designed to reduce shoaling in the HSC. SWG requested an updated validation of the previously developed AdH model of this area to calendar years 2010 and 2017, utilizing newly collected sediment data. Updated model inputs were supplied for riverine suspended sediment loads as well as for the ocean tidal boundary condition. The updated model shows good agreement to field data in most conditions but also indicates potential issues with freshwater flow inputs as well as the ocean salinity boundary condition.

24 Aug 2023

3D Measurements of Water Surface Elevation Using a Flash Lidar Camera

Abstract: This Coastal and Hydraulics Engineering technical note (CHETN) presents preliminary results from a series of tests conducted at the US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL), Field Research Facility (FRF), in Duck, North Carolina, to explore the capabilities and limitations of the GSFL16K Flash Lidar Camera in nearshore science and engineering applications. The document summarizes the spatial coverage and density of data collected in three deployment scenarios and with a range of tuning parameters and provides guidance for future deployments and data-collection efforts.

24 Aug 2023

Measuring Maritime Connectivity to Puerto Rico and the Virgin Islands Using Automatic Identification System (AIS) Data

Abstract: The purpose of this Coastal and Hydraulics Engineering technical note (CHETN) is to summarize a portion of recently published work (Young, Kress, et al. 2022) that used archival Automatic Identification System (AIS) data to measure the commercial vessel traffic connected to Puerto Rican and US Virgin Island (USVI) port areas from January 2015 to June 2020. Vessel movement derived from AIS was aggregated to construct a network that measured the port-to-port connectivity for all ports in the network and the interconnectivity of traffic between those ports. AIS data provided a description of vessel movement and the identification of specific vessel classes. Metrics such as interconnectedness can be used in conjunction with standard US Army Corps of Engineers (USACE) metrics describing waterway utilization, which traditionally have included total tonnage and specific commodity tonnage. The ability to consider the self-selected vessel-type broadcast via AIS, as well as dominant commodity type and tonnage reported through statistical publications, provides a fuller and more accurate description of waterway capacity utilization. This knowledge, along with port-to-port interconnectedness, reveals potential redundancies between ports, robustness across supply chains, and the impacts of seasonality, thereby allowing the USACE to expand its understanding of maritime supply-chain resilience.

24 Aug 2023

Geomorphic Metrics Used in FluvialGeomorph

Abstract: FluvialGeomorph (FG) is a geographic information system-based geomorphic analysis toolkit that analyzes high-resolution terrain data to provide river-reach assessments for watershed studies. This report demonstrates the utility of FG to identify physical stream channel characteristics that are used to determine channel stability. The FG toolbox is a remote-sensing approach based on lidar data, designed to measure channel, floodplain, valley, and watershed metrics necessary for watershed assessments. Currently, channel slope and cross-sectional analysis and planform metrics are being evaluated with existing lidar data from different hydrophysiographic regions within the United States. Recent study areas include the Northwest, Southwest, South, Midwest, and upper Midwest of the United States.