18 Feb 2025

Representation of Live-Fire Energetic Residues from Insensitive Mortar Munitions Using Command-Detonation Testing

Abstract: Command detonation is critical for testing munitions early in the acquisition process, however its representation of energetic residues produced during live fire has not been assessed. Energetic residue deposition rates were measured on snow from live fire of 60 mm and 81 mm IMX-104 mortar munitions and then compared results with previous command-detonation tests of the same munitions. Mean live-fire deposition rates of IMX-104 compounds were: 3800 mg NTO, 34 mg DNAN, 12 mg RDX, and 1.9 mg HMX per 60 mm cartridge (n = 9); and 8000 mg NTO, 60 mg DNAN, 20 mg RDX, and 2 mg HMX per 81 mm cartridge (n = 13). The predominant residue compound NTO was accurately estimated by command detonation for the 60 mm munition but was significantly underestimated for the 81 mm munition. The minor residues of DNAN and RDX were relatively well estimated by command detonation for the 81 mm munition (p = 0.07 and p= 0.014, respectively), but both were significantly underestimated (p < 0.0001) for the 60 mm munition. Despite some of these differences, the ability demonstrated here for command detonation to predict live-fire residue deposition rates to the correct order-of-magnitude supports its utility in assessing environmental impact.

14 Feb 2025

Validating Sediment Budgets Along the North Atlantic Coast Using the Updated Sediment Budget Calculator

Purpose: This Regional Sediment Management (RSM) technical note (TN) outlines two case studies validating the Sediment Budget Calculator (SBC) using accepted values from the literature and published sediment budgets. Initially developed by the US Army Corps of Engineers (USACE) as a web-based tool, the SBC calculates all viable sediment transport rates for an inlet environment given user-defined inputs. The next-generation SBC was converted into Python 3.9 to make it more accessible than the original C++ version. These case studies outline the efficacy of the SBC tool for deriving accurate and reliable sediment budget values. Finally, the TN discusses future SBC improvements and efforts to incorporate SBC results into the Sediment Budget Analysis System (SBAS).

13 Feb 2025

Upper Barataria Basin (UBB) Coastal Storm Risk Management (CSRM) Study : Probabilistic and Numerical Coastal Hazards Modeling

Abstract: This report summarizes the numerical modeling and probabilistic analysis performed by the US Army Engineer Research and Development Center Coastal and Hydraulics Laboratory (CHL) as part of the Upper Barataria Basin (UBB) Coastal Storm Risk Management (CSRM) Study. The intent of this work, performed for the US Army Corps of Engineers (USACE) and St. Paul District, was to evaluate project alternatives to assess flooding risks induced by coastal storms in coastal Louisiana. This study applied the USACE’s Coastal Storm Modeling System for storm surge and wave modeling and Coastal Hazards System–Probabilistic Framework (CHS-PF) to quantify water level and wave hazards, leveraging existing synthetic tropical cyclones (TCs) from the Coastal Hazards System¬–Louisiana (CHS-LA) study for levee recertification. Using a reduced storm suite (RSS) of synthetic TCs from CHS-LA, hydrodynamic model simulations were performed on an updated grid, including five proposed levee systems, to produce storm responses at more than 184,000 mesh node locations and over 21000 special save point locations within the UBB project area. Through the application of the CHS-PF, the joint probability analysis of TC atmospheric-forcing parameters and their associated storm responses were assessed for the estimation of still water level (SWL), significant wave height (Hm0), and wave peak period (Tp) annual exceedance frequencies ranging from 10 to 1 × 10−4 yr−1 to evaluate the impact of the UBB with- and without-project conditions.

12 Feb 2025

Cloud-Based Workflow to Process Regional Topobathymetric Lidar Datasets for Integrated USACE Shoaling Analyses

Purpose: This Coastal and Hydraulics Engineering Technical Note (CHETN) details a methodology to process and format regional topobathymetric datasets for use in the US Army Corps of Engineers (USACE) Corps Shoaling Analysis Tool (CSAT).

4 Feb 2025

Beneficial Use of Dredged Material for Submerged Aquatic Vegetation Habitats: Overcoming Challenges and Seeking New Opportunities

Purpose: There is a critical need to maintain and create conditions that are conducive for long-term survival of submerged aquatic vegetation (SAV) habitats, which provide multiple ecosystem services, using dredged material. This technical note (TN) was developed by the US Army Engineer Research and Development Center (ERDC)–Environmental Laboratory (EL) to address the specific challenges US Army Corps of Engineers (USACE) practitioners at the district and division level face that impede the development of beneficial use of dredged material (BUDM) projects to restore, conserve, and expand SAV habitats. Different ways to overcome these challenges and opportunities that should be further explored are also addressed. The information in this TN was synthesized from discussions at a virtual workshop for USACE practitioners.

3 Feb 2025

Notes on Bedload Sediment Collector Deployment: Eau Claire River, Wisconsin

Purpose: A bedload sediment collector field deployment was conducted during low flow conditions from August 2023 to September 2023 on the Eau Claire River, Wisconsin, to assess the operation and performance of a 12 ft bedload sediment collector (BSC). This initial deployment of the technology served to familiarize the research team with the new 12 ft BSC system in preparation for its potential deployment during high flow conditions and at other locations. The insights from this study are intended to identify opportunities to use this technology, particularly in the Upper Mississippi River navigation system.

3 Feb 2025

Mediated Model Development for Coastal Marsh Management in the Chesapeake Bay

Purpose: The purpose of this technical note is to develop a conceptual model that describes the critical processes, stressors, and interactions that affect coastal marsh dynamics within the Chesapeake Bay, as identified by subject matter experts, and then link those factors to specific management actions. Managing coastal marshes within Chesapeake Bay involves multiple stakeholders across federal, state, local, and nongovernmental agencies. Reaching consensus among large stakeholder groups can be difficult, since each has their own perspective and requirements for management. Mediated modeling is a technique that facilitates consensus building among stakeholders and provides a transparent roadmap for decision-making. This technical note describes how mediated modeling was applied to marsh management in Chesapeake Bay. On 4–5 May 2022, The Nature Conservancy (TNC) and the US Army Engineer Research and Development Center (ERDC) Integrated Ecological Modeling Team (EcoMod) partnered for a multistakeholder mediated modeling workshop to (1) build a conceptual model that depicts the relevant processes impacting marsh dynamics, and (2) identify indicators that are necessary for tracking marsh conditions, which inform needed management strategies. This conceptual model provides the foundation for the development of a marsh management decision framework that will use indicators to identify marsh conditions that subsequently trigger management decisions.

3 Feb 2025

Overview of a Rapid Discrete Infrared Acquisition System and Method for Automated Behavioral Analysis of Multiple Emissive Objects

Purpose: Many animal species form congregations on the landscape. These concentrations of animals provide an opportunity for biologists to conduct efficient population monitoring efforts. While general use of these sites is easy to document, continual monitoring is often problematic due to limited resources (time, expertise, etc.), potential for human disturbance on animal population and behavior, and an inability to determine an accurate assessment of counts. To allow for accurate and efficient assessment of animal numbers and usage of an area, an automated technology has been developed to monitor and characterize large animal concentrations. This automated technology provides information on population size, movement behavior characteristics, and other behavioral aspects of the target species.

30 Jan 2025

Investigation of Bioplastic Degradation for Military In-Field Applications Implementation of Sustainable Practices into the US Military for Rapid Biodegrading Polylactic Acid (PLA) Plastic in Compostable Environments

Abstract: The Army Climate Strategy has identified goals to reduce greenhouse gas (GHG) emissions to reach net-zero Army GHG emissions by 2050. Producing fossil-fuel-based plastics releases GHG emissions and plastic bottles are difficult to dispose, especially in contingency locations. Soldiers prefer hydrating with plastic water bottles, which leads to GHG emissions. This project investigates using bioplastics for water bottles. These bioplastics are produced from natural materials and can break down faster with alternative disposal methods, such as composting. Challenges include finding a material with a stable shelf life and the capability to hold water, but also one that that degrades with ease in the right composting environment. As part of this project, partners at the University of Minnesota are developing a new polylactic acid (PLA) material to fit the material properties needed for this application. Their research is ongoing. Construction Engineering Research Laboratory (CERL) researchers tested commercial PLA in calorimeter and incubator studies and with a full-scale demonstration of the commercial composting Sustainable Generation Mobile System. The PLA did not completely degrade, and testing showed mixed results on finished compost quality. Recommendations included continued testing, experimenting with other bioplastics, and changing compost feedstock variables.

30 Jan 2025

Rapid Assessment Tools for Estimating Trafficability of Low Volume Roads

Abstract: Rapid assessment of low-volume road surfaces remains a challenge when attempting to forecast allowable vehicle crossings. Variations in soil type, compaction effort, and moisture content of the soil can greatly affect trafficability, and predictive equations for soil deformation under vehicle loads often have reduced reliability for low-strength materials. Portable tools to characterize soil stiffness and corresponding relationships to load-induced deformation are needed. In this effort, researchers performed comparative testing of multiple rapid assessment tools as potential devices for giving estimations of vehicle trafficability. The test devices included a Clegg hammer and light weight deflectometer as instruments that measure response from impulse loading. Silty sand with and without chemical stabilization (using cement) at varying moisture content were used for testing. These soil states represented very weak conditions capable of supporting fewer than 50 vehicle passes to moderate strength conditions capable of supporting several thousand vehicle passes. Data from full-scale tests were used to correlate allowable traffic with data obtained from the rapid assessment tools. Recommendations from the effort include ranges of response data to categorize low-volume road surfaces based on their ability to handle ranges of vehicle loadings.