13 Mar 2025

Seasonality of Solute Flux and Water Source Chemistry in a Coastal Glacierized Watershed Undergoing Rapid Change: Wolverine Glacier Watershed, Alaska

Abstract: As glaciers rapidly lose mass, the tight coupling between glaciers and downstream ecosystems results in widespread impacts on global hydrologic and biogeochemical cycling. Knowledge of seasonally changing hydrologic processes and solute sources and signatures is limited. We conducted a broad water sampling campaign to understand the present-day partitioning of water sources and associated solutes in Alaska’s Wolverine Glacier watershed. We established a relationship between electrical conductivity and streamflow at the watershed outlet dividing the melt season into four hydroclimatic periods. Across hydroclimatic periods, we observed a shift in nonglacial source waters from snowmelt-dominated overland and shallow subsurface flow paths to deeper groundwater flow paths. We also observed the shift from a low- to high-efficiency subglacial drainage network and the associated flushing of water stored subglacially with higher solute loads. We used calcium from watershed outlet samples to estimate solute fluxes for each hydroclimatic period across two melt seasons. Between 40% and 55% of Ca2+ export occurred during the late season rainy period. Partitioning of the melt season coupled with a characterization of the chemical makeup and magnitude of solute export provides new insight into a rapidly changing watershed and creates a framework to quantify and predict changes to solute fluxes.

12 Mar 2025

Reading the Ground: Understanding the Response of Bioelectric Microbes to Anthropogenic Compounds in Soil Based Terrestrial Microbial Fuel Cells

Abstract: Electrogenic bacteria produce power in soil based terrestrial microbial fuel cells (tMFCs) by growing on electrodes and transferring electrons released from the breakdown of substrates. The direction and magnitude of voltage production is hypothesized to be dependent on the available substrates. A sensor technology was developed for compounds indicative of anthropological activity by exposing tMFCs to gasoline, petroleum, 2,4-dinitrotoluene, fertilizer, and urea. A machine learning classifier was trained to identify compounds based on the voltage patterns. After 5 to 10 days, the mean voltage stabilized (+/- 0.5 mV). After the entire incubation, voltage ranged from -59.1 mV to 631.8 mV, with the tMFCs containing urea and gasoline producing the highest (624 mV) and lowest (-9 mV) average voltage, respectively. The machine learning algorithm effectively discerned between gasoline, urea, and fertilizer with greater than 94% accuracy, demonstrating that this technology could be successfully operated as an environmental sensor for change detection.

12 Mar 2025

Collaborative Development of Natural and Nature-Based Solutions for Coastal Resiliency in the Arctic and Adjacent Regions: A Workshop

The workshop “Collaborative Development of Natural and Nature-Based Solutions for Coastal Resiliency in the Arctic and Adjacent Regions” was held in Reston, Virginia, October 24–25, 2023. The objective was to assemble diverse international partners in a hybrid in-person and virtual setting to focus on the viability of applying Nature-Based Solutions (NBS) to solve engineering challenges in the Arctic and similar cold region locations. The goals of the two-day workshop were to share recent efforts implementing NBS to mitigate coastal hazards such as flooding and erosion in northern high latitude settings and identify requirements and develop a robust program of activities to advance this work at national, regional, and local levels. This workshop report documents the presentations and discussion and summarizes key needs and recommendations for future engagement identified by speakers and workshop participants.

6 Mar 2025

New Construction Criteria for a Changing Arctic and Subarctic: The UFC 3-130 Series Revision Process

Abstract: The DoD operates significant and strategically important installations in the Arctic and Subarctic domain. Geopolitical, economic, and climatic changes require an upgraded ability to rapidly deploy and sustain forces into Arctic and Subarctic regions. Relevant engineering criteria and guidance to support these efforts are the Unified Facility Criteria 3-130–Arctic and Subarctic Construction (UFC 3-130) documents, originally a seven-volume series. The series has been ‘inactive’, indicating the specifications are not current and potentially technically noncompliant. Therefore, designers may resort to methods that do not meet current military or civilian standards, or they may use the outdated guidance leading to costly design and construction failures. Infrastructure owners and operators must be confident that up-to-date technology and criteria are specified to ensure life safety, mission readiness, and infrastructure longevity. This report highlights the process and resources used to generate a new five-volume UFC Arctic and Subarctic series that aligns with current technology and standards while also addressing a changing climate. These new documents are appliable for use by planners, engineers, and architects when planning, designing, constructing, and maintaining DoD infrastructure. The full UFC 3-130 series is available on the Whole Building Design Guide (WBDG) website at https://www.wbdg.org/dod/ufc.

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.

30 Jan 2025

Improved Trafficability Over Soft Soils Using Ground Matting

Abstract: Soft soils pose mobility challenges, even for vehicles designed with superior off-road capabilities. When numerous vehicles travel the same path, permanent deformation of the soil can result in rut depths that exceed vehicle ground clearance. These challenges can be overcome by modifying ground conditions to improve bearing capacity or spreading wheel loads over a greater area. Researchers at the U.S. Army Engineer Research and Development Center conducted field tests to quantify the performance benefits of a ground matting system made of connected fiberglass panels designed to improve vehicle mobility on soft soils. Soil conditions included silt, sand, and highly organic soil with varying strength. Test vehicles included wheeled trucks with gross weights of approximately 6350 kg per axle. Performance of the matting system was assessed by the number of allowable vehicle crossings with and without matting present. Results from testing showed that allowable number of vehicles increased by at least a factor of ten on the weakest soils. Data presented herein includes geotechnical site characterization, soil deformation as a function of traffic, and material characteristics for the fiberglass matting system.

9 Jan 2025

National Ordinary High Water Mark Field Delineation Manual for Rivers and Streams: Final Version

Abstract: The ordinary high water mark (OHWM) defines the lateral extent of non-tidal aquatic features in the absence of adjacent wetlands in the United States. The federal regulatory definition of the OHWM, 33 CFR 328.3(c)(4), states the OHWM is “that line on the shore established by the fluctuations of water and indicated by physical characteristics such as [a] clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.” This is the first manual to present a methodology for nationwide identification and delineation of the OHWM. A two-page data sheet and field procedure outline a weight-of-evidence (WOE) methodology to organize and evaluate observations at stream sites. This manual presents a consistent, science-based method for delineating the OHWM in streams. It also describes regional differences and challenges in identifying the OHWM at sites disturbed by human-induced or natural changes and illustrates how to use remote data to structure field inquiries and interpret field evidence using the principles of fluvial science. The manual demonstrates that, in many landscape settings, the OHWM may be located near the bankfull elevation.

2 Jan 2025

Assessing the Validity and Accuracy of Wetland Indicator Status Ratings for Eight Species in Alaska Subregions

Abstract: Preexisting ecological information and plant species occurrence data were used to determine the accuracy and validity of the present regional and subregional wetland indicator status ratings for eight species: Andromeda polifolia, Arctous rubra, Carex canescens, Rhododendron tomentosum, Rubus arcticus, Salix arctica, Salix pulchra, and Viola palustris. Technical documentation was developed to either (1) support the current National Wetland Plant List (NWPL) subregion boundaries and wetland indicator status ratings for the NWPL Alaska Region or (2) support a proposed change to the subregions or wetland indicator status ratings for the NWPL Alaska Region, for inclusion into the next NWPL update. The project developed repeatable, quantitative methods for assignment of wetland indicator status rating. Analyses included multiple correspondence analysis (MCA), analysis of similarities (ANOSIM), nonmetric multidimensional scaling (NMDS), and principal component analysis (PCA). Prevalence index (PI) was used as a numeric approximation of wetland status for comparing observations across subregions. A pilot study on S. pulchra data evaluated regional assignments by machine learning and assessed the feasibility of correlation network analysis and Louvain clustering for wetland indicator status rating assignment as dictated by co-occurring species. The methods developed for this Alaska-specific study may be applied to any future regional or subregional updates to the NWPL.

18 Dec 2024

The Effects of Physical Form, Moisture, Humic Acids, and Mixtures on the Photolysis of Insensitive Munitions Compounds

Abstract: The explosive formulations IMX-101 and IMX-104 are replacing conventional explosives in munitions, making them safer to transport and handle. However, munitions manufacturing and military training can lead to the environmental release of constituent insensitive munitions compounds. These IMCs absorb ultraviolet light and transform photochemically into products with potentially greater toxicity. This study explores the effects of physical form, moisture, humic acids, and compound mixtures on the photolysis of solid and dissolved IMCs under UV-A and UV-B light. Irradiation of dry vs. moist solid IMC crystals yielded few measured products, and while photolysis rates were not significantly different, they were orders of magnitude slower than for aqueous IMCs. There was no significant difference in photolysis rates for aqueous IMCs irradiated with 0, 0.4, and 4 mg L-1 humic acids, but 40 and 400 mg L-1 humic acids inhibited NTO and enhanced NQ photolysis. Although organic and inorganic products were detected in the mixtures, an average of 15–35 % of the theoretical starting IMC masses was not accounted for. Overall, aqueous IMCs transformed 4–48 times faster than the solid IMCs, but the environmentally-relevant conditions tested were found to play a minor role in IMC photolysis.

19 Nov 2024

Finite Element Modeling of Aquatic Electrical Barriers—Voltage and Current Distributions: Brandon Road Lock and Dam Interbasin Project—Electric Fish Deterrent Design Recommendations

Abstract: Invasive carp (black, grass, silver, and bighead) are native to Asia and were imported into the US during the 1970s and 1980s to help fish farmers manage water quality and vegetation. Unfortunately, these carp became established in the Mississippi River and have led to a decline in native fish species. To prevent their spread from the Mississippi River Basin to the Great Lakes Basin via the Chicago Area Waterway System (CAWS), the US Army Corps of Engineers (USACE) operates a series of four electric dispersal barriers near Romeoville, Illinois in the Chicago Sanitary and Ship Canal (CSSC). To supplement these barriers, USACE was authorized to construct a series of aquatic nuisance species deterrents, including an electric deterrent, approximately 11 river miles downstream at Brandon Road Lock and Dam (BR). Throughout the BR electric deterrent design process, the dispersal barriers at the CSSC have served as the prototype systems used in the development of the concepts. Additionally, USACE has worked with the US Army Cold Regions Research Engineering Laboratory (CRREL) to develop a finite element numerical model (COMSOL) that predicts voltage and electric current distributions for a given electrode and waterway geometry.