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.

13 Sep 2023

Cold Impacts on Vehicle Electrical Systems: Developing a Baseline for Cold Testing Military Vehicles

Abstract: Low temperatures can significantly affect vehicle operation. While many of the effects, like increased fluid viscosity and decreased battery capacity, are well documented, the impacts on the electrical system as a whole are not. The objective of this study was to investigate the impacts of temperature on the electrical systems of select military vehicles and to develop a baseline for future testing. A High Mobility Multipurpose Wheeled Vehicle (HMMWV), a Heavy Expanded Mobility Tactical Truck (HEMTT), and a four-person diesel Polaris MRZR D4 were subjected to 15°C, 0°C, and −15°C temperatures while the loads on the battery and alternator were monitored. The HMMWV and MRZR were able to start on the first try for all tests. They both showed a slight increase in vehicle load current draw from the alternator as temperatures decreased. Future testing with more iterations and at lower temperatures will help identify clearer trends and improve testing procedures. As the Army becomes more reliant on electronic systems, it is becoming increasingly important that we understand how various climates will impact them.

12 Sep 2023

UGV SLAM Payload for Low-Visibility Environments

Abstract: Herein, we explore using a low size, weight, power, and cost unmanned ground vehicle payload designed specifically for low-visibility environments. The proposed payload simultaneously localizes and maps in GPS-denied environments via waypoint navigation. This solution utilizes a diverse sensor payload that includes wheel encoders, inertial measurement unit, 3D lidar, 3D ultrasonic sensors, and thermal cameras. Furthermore, the resulting 3D point cloud was compared against a survey-grade lidar.

12 Sep 2023

The Use of Native Vegetation for Structural Stability in Dredged Material Placement Areas: A Case Study of Beneficial Use Site 4A, Chocolate Bayou, Brazoria County, Texas

PURPOSE: This technical note is the third in a series about using native plant communities to enhance dredge material placement areas (DMPAs), confined disposal facilities (CDFs), and projects where dredged sediments are used for various engineering purposes. DMPAs and CDFs occur in numerous locations spanning different geographic locations nationwide. Oftentimes, these containment dikes are constructed using earthen materials. The materials are either barged in from an off-site location or obtained on-site from new or virgin materials, consisting of heavy clay particles and sediments removed from the nearby channel. In the Gulf Coast region of the United States, new or virgin materials are obtained during channel deepening activities using mechanical or hydraulic dredging methods. Examples of these dredging methods include hopper dredge, pipeline dredge, and excavator or bucket dredge. When materials are considered suitable for beneficial use purposes, and following environmental compliance, the materials are often used to construct containment dikes in DMPAs and CDFs. The project site used in this study—Beneficial Use Site 4A (BUS 4A)—used dredged material during its construction and has periodically received dredged material to maintain its target elevation of 2 ft (0.67 m) above the mean lower low water; hence, this site presents an opportunity for use as a demonstration study. Project goals include (1) demonstrating the use of native plant communities to provide structural stability, (2) introducing targeted vegetation establishment on DMPAs and CDFs as a management strategy to improve engineering and environmental outcomes, and (3) providing technology transfer to the U.S. Army Corps of Engineers (USACE) districts through hands-on planting techniques and installation of natural material (in this demonstration, coir logs).

11 Sep 2023

The Use of Native Vegetation and Natural Materials in Shoreline Stabilization: A Case Study of Bubble Gum Beach, Rehoboth Beach, Delaware

PURPOSE: This technical note is the fourth in a series about using native plant communities to achieve engineering and ecological purposes such as shoreline stabilization, structural enhancements, habitat creation, and ecosystem development. In this series, we demonstrate the utility of natural materials (specifically, native vegetation, oyster reefs, and coir logs) in living shoreline projects. Plant species and plant communities play critical roles in wave attenuation and sediment accretion in coastal areas. The application of vegetation in the coastal areas, especially on the East and Gulf Coasts, has focused heavily on the creation of living shorelines—serving both environmental and engineering purposes. This technical note documents the workshop conducted by the US Army Engineering Research and Development Center (ERDC) and hosted by the US Army Corps of Engineers’ (USACE) Philadelphia District (NAP) and Center for the Inland Bays. The goals of this technical note are (1) to demonstrate the application of native plant communities, oyster shells, and coir (coconut) materials and their installation techniques along shorelines to the engineering community; (2) to demonstrate how targeted vegetation establishment can facilitate ecosystem development along shorelines to improve engineering and environmental outcomes; and (3) to provide native vegetation installation techniques for living shorelines projects’ purposes.

11 Sep 2023

Selection of a Time Series of Beneficial Use Wetland Creation Sites in the Sabine National Wildlife Refuge for Use in Restoration Trajectory Development

PURPOSE: The development of regional restoration trajectories of marsh creation and nourishment projects is key to improved design, management, and implementation of adaptive management principles. Synthesizing information from multiple marsh creation projects constructed at various times but with consistent site characteristics and borrow material sources, helps elucidate restoration success in a specific region. Specifically, this technical note (TN) documents the process of determining a suitable study area, construction methods, and the current state of establishing sites in the Louisiana Gulf Coast that could be used for restoration trajectory development. This investigation compiled information from the construction phases, Landset 8 satellite imagery, and the most recent digital elevation model (DEM) to investigate elevation and vegetation establishment within these sites.

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

Resilience Modeling for Civil Military Operations with the Framework Incorporating Complex Uncertainty Systems

Abstract: Framework Incorporating Complex Uncertain Systems (FICUS) provides geographic risk analysis capabilities that will dramatically improve military intelligence in locations with the Engineer Research and Development’s (ERDC) demographic and infrastructure models built and calibrated. When completed, FICUS would improve intelligence products by incorporating existing tools from the National Geospatial Intelligence Agency, ERDC, and FICUS prototype models, even in places without demographic or infrastructure capabilities. FICUS would support higher-fidelity intelligence analysis of population, environmental, and infrastructure interaction in areas with Human Infrastructure System Assessment (HISA) and urban security models built and calibrated. This technical report will demonstrate FICUS prototype tools that allow Civil Affairs Soldiers to provide situational awareness information via a browser interface.