8 Oct 2024

Remote Monitoring of Cathodic Protection Systems on Navigable Waterways

Abstract: Cathodic protection is one of the main modes of corrosion prevention for structures in navigable waterways. The rectifier output voltage must be in a specific range to provide effective protection against corrosion. This effort was designed to monitor, predict, and stabilize the efficacy of multiple cathodic protection systems. Copper/copper-sulfate half-cell electrode sensors, water quality sensors, and gauges for rectifier output were connected to modems at multiple locks so the data could be analyzed to create a predictive maintenance algorithm.

8 Oct 2024

Identifying Sustainability and Resilience Investments to Implement the 2022 US Army Climate Strategy: Fiscal Year 2023 Sustainable Design and Development Update

Abstract: This report offers a detailed assessment of the US Army’s adherence to sustainable design and development (SDD) policies, encompassing the US Army Sustainable Design and Development (SDD) Policy memorandum; Unified Facilities Criteria (UFC) 1-200-02, High Performance and Sustainable Building Requirements; Executive Orders 14,008 and 14,057; the Army Climate Strategy; and required LEED v4 certifications. The evaluation comprises five primary tasks, including quarterly reports on US Army military construction (MILCON) project LEED v4 certifications, analysis of US Army LEED v4 certifications and trends, research and implementation of the intermediate objectives in the 2022 US Army Climate Strategy focusing on strategies to achieve climate goals, an analysis ex-plaining the advantages of Performance Excellence in Electricity Renewal (PEER) certification for Army microgrids, and industry knowledge gained from participation in the Greenbuild 2022 conference. Key recommendations developed in this assessment include enhancing transparency in LEED reporting, considering PEER certification, expediting climate strategy implementation, and active participation in industry gatherings. This report serves as a comprehensive resource for informed decision-making, aiding the US Army in advancing its sustainable design and development initiatives to meet future environmental and sustainability objectives.

7 Oct 2024

Seismic analysis for Pohnpei Island, Federated States of Micronesia

Abstract: The purpose of this study was to determine the seismic hazards that can affect Pohnpei Island and provide estimates of the ground motion parameters. The primary parameters are peak ground acceleration (PGA), pseudo-spectral acceleration (PSA), and velocity. These values were determined both probabilistically and deterministically to illustrate the overall seismic hazard to Pohnpei Island. A review was conducted of the technical literature to determine geologic studies that have been performed for characterization of the island’s volcanism, stratigraphy, and tectonism. This report is a desktop study that examines the tectonism of the region, the geology of the island, its geologic history, and its seismic record. No liquefaction areas or tsunami hazards were identified by researchers on the island.

7 Oct 2024

Full-Scale Evaluation of Saltwater Concrete for Airfield Pavement Construction and Repair

Abstract: The US Navy has a need to rapidly construct concrete facilities onshore to support contingency operations. Mixing water for concrete is typically specified to be freshwater; however, in many scenarios there are limited amounts of freshwater available for construction. Thus, use of readily available saltwater would be advantageous. This project’s objective was to evaluate the suitability of saltwater as a replacement for freshwater for producing concrete airfield pavement under relevant operational scenarios. Three full-scale test sections were constructed, and performance was evaluated in the context of relatively short design life requirements. First, direct comparison slabs of freshwater and saltwater concrete were constructed and exposed to ambient environmental conditions for one year; periodic concrete strength measurements were made. Next, 8 in. thick and 11 in. thick saltwater concrete pavements were constructed then subjected to P-8 aircraft accelerated loading. Finally, four airfield damage repair techniques were executed using saltwater and subjected to accelerated P-8 aircraft loading. Saltwater concrete performance was found to be similar to freshwater concrete for all scenarios investigated. The overall conclusion was that saltwater can be used in place of freshwater for concrete airfield pavement construction and repair for short- to medium-term use (1–2 yr) with no meaningful impact to mission requirements.

3 Oct 2024

Comite Diversion Numerical Model Study

Abstract: The Comite River diversion project is designed to reduce flooding along the Comite and Amite Rivers during flood events by diverting flow from the Comite River into the Mississippi River above Baton Rouge, Louisiana. The flow is diverted from the Comite River along a diversion canal to the Lilly Bayou Control structure. This structure allows the Comite River flow to enter the Mississippi River floodplain. A numerical model was created to evaluate the impacts associated with this addition of water to the Mississippi River. A 2D Adaptive Hydraulics numerical model was created to quantify the system impacts associated with the diverted flow in conjunction with possible system modifications to control the flow pathway. The impact of the diversion was determined to be heavily dependent on the flow and stage of the Mississippi River. At higher stages and flows, the flow diverted by the Lilly Bayou Control structure is negligible in relation to the much larger Mississippi River flow and therefore the impacts of the added flow are significantly less than at lower Mississippi River stages. At lower Mississippi River flows and stages, the added flow from the Lilly Bayou Control structure has a larger impact on the inundation due to the larger relative amount of diverted flow in relation to the Mississippi River. Ultimately, the diverted Comite River flow has some incremental increase in water levels at all Mississippi River stages.

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.