19 Jul 2024

Permafrost and Groundwater Characterization at the Proximity of the Landfill, Fort Wainwright, Alaska

Abstract: This report summarizes a site investigation at the vicinity of the landfill, a discontinuous permafrost site, at Fort Wainwright, Alaska. The objective of this effort was to characterize the permafrost extent and groundwater flow at the study area, and to compare newly collected subsurface characteristics with historical datasets. The main tasks for this effort included lidar and remote sensing analyses, geophysical investigations, a tracer dye study, contaminant trend analysis, and installation of soil temperature sensors. Findings included changes in stream channels and watershed boundaries, and elevation losses (0.2 m to 1 m) east and northeast of the landfill. From frost probe measurements, we found that depths to permafrost were up to 1.5 m deeper in 2021 than in 2010 where the difference in depth ranged from 20% to more than 350%. Furthermore, we detected a reduction in lateral permafrost extent from geophysical datasets. The groundwater flow direction, as detected through the dye study, was south to southwest. Dye was detected up to 2,300 m from the injection point. Groundwater travel times, as calculated from the dye study, varied greatly. For upcoming historical comparisons, it is recommended that data collections are performed using similar methods as described in this study.

16 Jul 2024

Evaluation of the Version 1 Advanced Tactical Awareness Kit–Expeditionary Radar (ATAK-ER V1) for Accuracy and Reliability in Surf-Zone Characterization in a Range of Environmental Conditions

Abstract: This Coastal and Hydraulics Engineering Technical Note (CHETN) presents the evaluation of a rapidly deployable radar and associated software for characterizing surf-zone waves, currents, and bathymetries at the US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL), Field Research Facility (FRF), in Duck, North Carolina. This project was conducted at the request of the US Marine Corps (USMC) Warfighting Laboratory. The Version 1 Advanced Tactical Awareness Kit–Radar Expeditionary (ATAK-ER V1) system was deployed 15 times between July and August 2023 to observe a range of wave, water level, and wind conditions that could each affect radar processing. Products from the system were then compared to the FRF’s continuously operating in situ instruments and monthly bathymetric surveys to quantify the accuracy and reliability of the output. A number of issues with the unit are identified, including potential error sources contributing to inaccuracies, but the black-box nature of the commercial off-the-shelf (COTS) unit prevents a confident understanding of why wave heights are underpredicted (by 65% on average), why bathymetries consistently have root-mean-square errors (RMSE) over 1 m with progressively greater errors with distance offshore, or why some collections are unable to generate all of the advertised products. This Version 1 COTS unit is not recommended for operational use at this time.

12 Jul 2024

Qualitative Habitat Evaluation Index for Louisville Streams (QHEILS)

Purpose: Urban stream restoration typically involves multiple objectives addressing different aspects of ecosystem integrity, such as habitat provision, geomorphic condition, watershed connectivity, water quality, and land-use change. Multiple stream assessment tools and models have been developed and applied to inform restoration prioritization, planning, and design. Here, we present the Qualitative Habitat Evaluation Index for Louisville Streams (QHEILS, pronounced “quails”), which was designed as an interdisciplinary assessment method for urban streams in the Louisville, Kentucky, metropolitan region. The model adapts a regional habitat assessment procedure, the Qualitative Habitat Evaluation Index (QHEI), by incorporating additional processes related to geomorphic change and watershed connectivity. The QHEILS was developed in the context of the Beargrass Creek Ecosystem Restoration Feasibility Study, and it provides a rapid procedure for assessing multiobjective benefits associated with proposed restoration actions. This technical note summarizes the model and provides example applications within the Beargrass Creek watershed.

11 Jul 2024

Sharing Ships’ Weather Data via AIS: Concept and Results from Multiyear Observations

Abstract: The purpose of this Coastal and Hydraulics Engineering technical note (CHETN) is to discuss the concept, demonstrations, and the initial results of multiyear proof-of-concept testing of the capability to share weather data from ships via the Automatic Identification System (AIS). Technical foundations of this process were described by Tetreault and Johnson (2020) with partial results described in Johnston et al. 2021. The updated results in this CHETN include evaluation of the efficacy of the various application-specific message (ASM) formats use to communicate the weather observations and data reception results for selected vessels that have been participating in the proof-of-concept field deployment since 2019 or later.

11 Jul 2024

Mississippi River AdH Model Modification and Evaluation, Thebes, Illinois, to Birds Point, Missouri, Reach

Abstract: A calibrated hydrodynamic and sediment transport model of the Upper Mississippi River, from Thebes, Illinois, to Birds Point, Missouri, was created to investigate hydraulics and sediment transport in the river channel and across the Dogtooth Island Peninsula (DIP) as the result of the Len Small levee breach. A hydrodynamic model was developed for the reach and calibrated to stage and breach outflow discharge data for the floods of 2011, 2015–2016, and 2017. The hydrodynamic model was used to investigate breach outflow discharges and shear stress distribution over the DIP. Soil and geologic maps were investigated to determine soil parameters and the long-term stability of soil formations on the DIP. The Upper Mississippi River sediment transport model was built upon the hydrodynamic model and soil mapping efforts. The sediment transport model was calibrated to the 2015 and 2017 flood events. Calibration data were limited to changes in elevation, which were then areally averaged, computed from comprehensive channel surveys and lidar data for the DIP. This model provides a solid foundation for comparing alternative measures to minimize further erosion of the DIP and for analyzing the risk of a channel cutoff occurring.

11 Jul 2024

Environmental DNA (eDNA) Assays for the Detection of Ridgway’s Rail (Rallus obsoletus) in the United States

Abstract: We designed two novel environmental DNA (eDNA) assays for the detection of Ridgway’s Rail (Rallus obsoletus), and successfully validated each assay using eDNA samples collected from the species’ known distribution within the United States. These assays add to the suite of tools available for the monitoring of this rare and secretive marsh bird, and may help to further elucidate its movement patterns as well as identify important migration corridors. Observed sensitivity of the assays indicates exceptional performance, with limits of detection at ≤ 8 copies of the target eDNA fragment per reaction. Our publication adds to the growing body of literature supporting eDNA surveys as viable tools for bird monitoring endeavors.

11 Jul 2024

Sliver Spall Mitigation: Field Investigation, Laboratory Study, and Mixture Proportioning Analysis

Abstract: A combined field and laboratory study was conducted to identify factors contributing to sliver spall of concrete pavements and recommend avenues for prevention. In this study, spall density maps of eight airfields were created, and cores were taken for petrographic analysis. A companion laboratory study evaluated nondestructive testing equipment for identifying concrete prone to sliver spalling. Concrete mix designs with good and poor performance were analyzed for trends in mixture proportioning and aggregate gradation. Spall density mapping indicated sliver spalling was more likely to occur on longitudinal joints and that the distress was not solely a material or mixture design-related issue. The laboratory study concluded that surface resistivity measurements were able to differentiate edge-finishing techniques (normal versus overworked, mortar-rich edge) after seven days of curing. An analysis of particle packing theory and mixture proportioning trends showed there was substantial overlap in the gradations for good and poor performing pavement. Thus, acceptable mixture designs can produce poor quality pavement if not constructed properly. The main contributors to early age sliver spalling of concrete airfield pavement occur during pavement construction.

11 Jul 2024

Composite Material Applications and Research Roadmap for US Army Corps of Engineers Civil Works

Abstract: This report discusses and ranks the remaining research, development, and deployment opportunities for fiber-reinforced polymer composite materials in USACE marine infrastructure applications. Following the successes of at least 10 fiber-reinforced polymer composite pilot projects from 2015 to 2022, Public Law 117-58, the Infrastructure Investment and Jobs Act, allocated funding for a roadmap report that articulates lingering implementation barriers and prioritizes steps to overcome those challenges through laboratory and field experimentation. The objective analysis herein draws from real Operational Condition Assessment data generated in the field. Key opportunities lie in inspection techniques, standardized design approaches for molded components, and improved guidance to ad-dress abrasion, fatigue, and concentrated load cases at the 10-meter scale.

10 Jul 2024

Seasonal Variation in Near-Surface Seasonally Thawed Active Layer and Permafrost Soil Microbial Communities

Abstract: Understanding how soil microbes respond to permafrost thaw is critical to predicting the implications of climate change for soil processes. However, our knowledge of microbial responses to warming is mainly based on laboratory thaw experiments, and field sampling in warmer months when sites are more accessible. In this study, we sampled a depth profile through seasonally thawed active layer and permafrost in the Imnavait Creek Watershed, Alaska, USA over the growing season from summer to late fall. Amplicon sequencing showed that bacterial and fungal communities differed in composition across both sampling depths and sampling months. Surface communities were most variable while those from the deepest samples, which remained frozen throughout our sampling period, showed little to no variation over time. However, community variation was not explained by trace metal concentrations, soil nutrient content, pH, or soil condition (frozen/thawed), except insofar as those measurements were correlated with depth. Our results highlight the importance of collecting samples at multiple times throughout the year to capture temporal variation, and suggest that data from across the annual freeze-thaw cycle might help predict microbial responses to permafrost thaw.

10 Jul 2024

Historic Landscape Inventory for Zachary Taylor National Cemetery, Louisville, Kentucky

Abstract: This project was undertaken to provide the US Department of Veterans Affairs, National Cemetery Administration, with a cultural landscape inventory of Zachary Taylor National Cemetery via funding from the St Louis Mandatory Center of Expertise (MCX) for the Curation and Management of Archaeological Collections (CMAC). The 16-acre cemetery, listed on the National Register of Historic Places in 1983, is found in Louisville, Kentucky, and contains more than 11,400 burials. The US Army Engineer Research and Development Center-Construction Engineering Research Laboratory (ERDC-CERL) was tasked with inventorying and assessing the cultural landscape at Zachary Taylor National Cemetery through the creation of a landscape development context, a description of current conditions, and an analysis of changes to the cultural landscape over time. All landscape features were included in the survey as federal policy on national cemeteries requires that all national cemetery landscape features be considered contributing elements, regardless of age. The historic landscape elements of the cemetery, like the original overarching Beaux-Arts plan and circulation, cannot be restored due to the current number of burials. However, some elements can be reemphasized by historic landscape management planning, such as the restoration of the portions of the allée of pin oak (Quercus palustris) trees.