30 Sep 2024

A Review of Habitat Modeling Methods That Can Advance Our Ability to Estimate the Ecological Cobenefits of Dredge Material Placement

Abstract: Beneficial use of dredged material (BUDM) has been a placement strategy within the USACE for over 35 years, with applications that aim to reduce navigation costs, increase flood protection, and generate ecological benefits. However, the tools and approaches used for estimating ecological benefits are often limited in comparison with those available to evaluate costs and more traditional economic benefits when moving and placing dredged material. There are statistical and mechanistic models that can aid in quantifying habitat benefits within the context of BUDM projects, but there is currently no USACE-approved process that facilitates the integration of these modeling approaches. The purpose of this document is to provide a comprehensive review of existing habitat-centric statistical and mechanistic models that may aide the USACE in identifying models most appropriate for quantifying potential ecological benefits and trade-offs at placement sites.

27 Sep 2024

Advancements in Riverine Fish Movement Modeling: Bridging Environmental Complexity and Fish Behavior

Abstract: Understanding fish movement and response in relation to their environment near infrastructure and migratory barriers is crucial for developing sustainable fisheries management solutions. Intermediate-scale movement models are a contemporary approach for understanding and predicting movement patterns of riverine fish considering their changing environment, which is predominately water flow. These models can be complex and require interdisciplinary knowledge. For more than 60 years, different approaches have been developed for investigating, reproducing, and predicting the movement outcomes of fish decision making. Due to the breadth of model frameworks available, a systematic review is helpful to summarize the available knowledge including a description of general model properties, environment modeling, agent characteristics, and methods of data use, output, and validation. The analysis of 38 studies found a wide range of model frameworks and architectures. Despite the lack of consistency, each model imposed some combination of the following behaviors: response to flow direction (i.e., rheotaxis), response to flow velocity magnitude, response to turbulence, response to depth, and memory/experience of the individual. There is a clear need for more consistent modeling approaches, increased consideration of memory/experience, inclusion of a wider range of species, incorporation of more detailed environmental covariates, and use of time-dependent solutions in fish movement models.

27 Sep 2024

Habitat and Landcover Classification and Maritime Forest Restoration Recommendations for Deer Island, Mississippi

Abstract: This report addresses two objectives: (1) an island-wide survey and mapping initiative to document habitat and landcover types present on Deer Island, Mississippi, and (2) an evaluation of forested resources on Deer Island along with recommendations to improve and expand the extent of maritime forests on the island. Diverse habitats were documented, including more than 30 distinct habitat and landcover types ranging from wetland marshes to maritime forests and sand ridges. The habitat and landcover survey (and accompanying maps) support ongoing and future ecosystem restoration activities, provides baseline data to conduct change analysis over time, and informs decision-making related to the management of the island’s natural resources. Additionally, the characterization of Deer Island’s forests documented a range of forest health conditions dictated by elevation gradients, soils, invasive species presence, and other factors. Collectively, the data presented inform ongoing planning efforts related to restoration activities on the island as well as future management opportunities to ensure Deer Island continues to provide ecological functions that benefit the community of Biloxi, Mississippi. The results and recommendations herein are broadly applicable to other barrier islands across the northern Gulf region and promotes additional research into the ecology of these unique coastal features.

27 Sep 2024

Potential Engineering With Nature Features to be Incorporated at Woodtick Peninsula

Purpose: Woodtick Peninsula is a barrier peninsula in western Lake Erie where restoration activities are being planned to combat erosion of the peninsula wetlands through placement of dredged material. As part of the restoration effort, design of an artificial reef is currently underway to function as a breakwater, preventing erosion of the fine-grained material being hydraulically placed along the west side of the peninsula. To the extent possible, it is desirable to design the reef such that it would not only provide erosion protection, but also incorporate features that would provide habitat, and thereby support the goals of Engineering With Nature® (EWN®). EWN is a concept focused on aligning natural and engineering processes to deliver economic, environmental, and social benefits efficiently and sustainably through collaboration. A range of breakwater and shoreline armoring alternatives have been utilized in coastal environments to enhance habitat. While a number of alternatives have been successfully demonstrated in marine waters, fewer structures have been adapted to freshwater systems of the Great Lakes. However, there have been several demonstrations within the Great Lakes in which breakwater structures have been enhanced to incorporate habitat features. In this report, potential designs for breakwaters and shoreline edging in freshwater systems that can incorporate EWN benefits are summarized.

27 Sep 2024

Beneficial Use of Dredged Sediment in South St. Paul, Minnesota: 100 Years of Economic, Social, and Environmental Innovation

Purpose: This technical note provides a review of beneficial use (BU) of dredged sediment in a 5-mile river reach of the Upper Mississippi River System (UMRS) that demonstrates the triple-win solutions championed by the US Army Corps of Engineers (USACE) Engineering With Nature® Program. Several case studies exemplifying the BU of dredged sediment are presented along with a more in-depth review of the Pigs Eye Lake Islands ecosystem restoration project.

27 Sep 2024

Surveys in Native and Introduced Ranges (2018–2021) for Natural Enemies of Yellow Floating Heart, Nymphoides peltata Kunth

Abstract: Yellow floating heart (Nymphoides peltata), a widespread aquatic invasive plant in the US, is currently under investigation for biological control de-velopment. From 2018 to 2021, we conducted native (Europe: 14 loca-tions; Asia: 80 locations) and introduced (US: 39 locations) range surveys to create a list of candidate agents and collect baseline infestation data for comparison. We genetically characterized populations and determined those most-closely related to US N. peltata were European. However, we found no promising agents in that region, except for previously reported fungal pathogens. In Asia, several herbivores were identified as potential agents based on observed damage in situ and previous literature reports about host specificity. These included three species of Bagous weevils, one of which may be Bagous charbenensi, and an unidentified leaf-mining Hy-drellia fly. During domestic surveys, generalist leaf-cutting caterpillars were common, similar to the native range. A major discovery was the dam-aging fungal pathogen, Septoria villarsiae, isolated from plants in a pri-vate pond in Maine—the first record in the Western hemisphere. The next steps for this program should include preliminary host specificity and im-pact assessments of S. villarsiae, the fruit-feeding Bagous spp. in China and Korea, and the leaf-mining Hydrellia sp. fly from South Korea.

26 Sep 2024

A Geospatial Model for Identifying Stream Infrastructure Locations

Abstract: Management of hydraulic infrastructure for flood control, hydropower, navigation, and water supply is a critical component of the Army Dams and Transportation Infrastructure Program (ADTIP). This project provides a tool to locate stream infrastructure using a one-dimensional approach supplemented with geospatial filtering that only needs digital elevation model (DEM) files as primary input. The regions in and around Forts Liberty, Sill, and Cavazos were selected as study areas, and stream networks with corresponding stream elevation profiles were created and searched for elevation changes that met vertical threshold and search window criteria. Recall, Fβ, and a ratio of under to overprediction were used to evaluate performance. The search algorithm generally overpredicts the number of stream infrastructure locations and especially so for large search windows (20 or 25 cells) and small vertical threshold values (5 or 10 m). Overall, it was found that midrange vertical threshold values (2 or 2.5 m with long search windows (20 or 25 cells) with the land cover classification (LCC) check applied yielded results that minimized false negatives and overpredictions. The significance of this tool is that it may reduce costly field investigations, or at least aid in the prioritization of site visits for hydraulic infrastructure managers.

26 Sep 2024

High-Rate Characterization and Modeling of a Hyperelastic Block Copolymer Subjected to Ballistic Impact

Abstract: A polystyrene-polyisobutylene-polystyrene star-block copolymer (PS-PIB-PS) is a thermoplastic elastomer with visco hyperelastic characteristics that displays a high level of toughness and performs well in shock attenuating applications. The research goal is to investigate experimentally and numerically the capacity of PS-PIB-PS to dissipate kinetic energy and examine its deformation and failure modes under impact by spherical steel projectiles at speed ranges of 200–1,700 m/s. First, PS-PIB-PS is characterized using a Split-Hopkinson Pressure Bar to measure high strain rate response and calibrate a hyperelastic material model. Second, ballistics tests are conducted on 12 in. × 12 in. PS-PIB-PS targets with various thicknesses to determine the ballistic limit and residual velocity (Vr) versus impact velocity (Vi) relationship. Finally, ALE3D is used to model the ballistic response and capture the extreme deformation observed during testing. During ballistic impact tests, significant deformation occurred on the backside of polymer targets, followed by perforation of the polymer, culminating with retraction and recovery of the polymer in a self-healing manner. Numerical simulations captured the deformation behavior during impact and predicted the Vr versus Vi response with high accuracy. This research provides a method of modeling hyperelastic materials subjected to ballistic impact and provides a better understanding of energy dissipation of these materials.

25 Sep 2024

Comparing the Thermal Infrared Signatures of Shallow Buried Objects and Disturbed Soil

Abstract: The alteration of physical and thermal properties of native soil during object burial produces a signature that can be detected using thermal infrared (IR) imagery. This study explores the thermal signature of disturbed soil compared to buried objects of different compositions (e.g., metal and plastic) buried 5 cm below ground surface (bgs) to better understand the mechanisms by which soil disturbance can impact the performance of aided target detection and recognition (AiTD/R). IR imagery recorded every five minutes were coupled with meteorological data recorded on 15-minute intervals from 1 July to 31 October 2022 to compare the diurnal and long-term fluctuations in raw radiance within a 25 × 25 pixel area of interest (AOI) above each target. This study examined the diurnal pattern of the thermal signature under several varying environmental conditions. Results showed that surface effects from soil disturbance increased the raw radiance of the AOI, strengthening the contrast between the object and background soil for several weeks after object burial. Enhancement of the thermal signature may lead to expanded windows of object visibility. Target age was identified as an important element in the development of training data sets for machine learning (ML) classification algorithms.

25 Sep 2024

Thermography Conversion for Optimal Noise Reduction

Abstract: Computer vision applications in terms of raw thermal radiance are limited by byte size. Normalizing the raw imagery reduces functional complexities that could otherwise aide a computer processing algorithm. This work explores a method to normalize 16-bit signed integer (I16) into unsigned 8-bit (U8) while maintaining the integrity of the correlation coefficients between the raw data sets and the environmental parameters that affects thermal anomaly detectability.