28 Sep 2022

A Fuzzy Epigenetic Model for Representing Degradation in Engineered Systems

Abstract: Degradation processes are implicated in a large number of system failures, and are crucial to understanding issues related to reliability and safety. Systems typically degrade in response to stressors, such as physical or chemical environmental conditions, which can vary widely for identical units that are deployed in different places or for different uses. This situational variance makes it difficult to develop accurate physics-based or data-driven models to assess and predict the system health status of individual components. To address this issue, we propose a fuzzy set model for representing degradation in engineered systems that is based on a bioinspired concept from the field of epigenetics. Epigenetics is concerned with the regulation of gene expression resulting from environmental or other factors, such as toxicants or diet. One of the most studied epigenetic processes is methylation, which involves the attachment of methyl groups to genomic regulatory regions. Methylation of specific genes has been implicated in numerous chronic diseases, so provides an excellent analog to system degradation. We present a fuzzy set model for characterizing system degradation as a methylation process based on a set-theoretic representation for epigenetic modeling of engineered systems. This model allows us to capture the individual dynamic relationships among a system, environmental factors, and state of health .

27 Sep 2022

Wave Attenuation of Coastal Mangroves at a Near-Prototype Scale

Abstract: A physical model study investigating the dissipation of wave energy by a 1:2.1 scale North American red mangrove forest was performed in a large-scale flume. The objectives were to measure the amount of wave attenuation afforded by mangroves, identify key hydrodynamic parameters influencing wave attenuation, and provide methodologies for application. Seventy-two hydrodynamic conditions, comprising irregular and regular waves, were tested. The analysis related the dissipation to three formulations that can provide estimates of wave attenuation for flood risk management projects considering mangroves: damping coefficient β, drag coefficient CD, and Manning’s roughness coefficient n. The attenuation of the incident wave height through the 15.12 m long, 1:2.1 scale mangrove forest was exponential in form and varied from 13%–77%. Water depth and incident wave height strongly influenced the amount of wave attenuation. Accounting for differences in water depth using the sub-merged volume fraction resulted in a common fit of the damping coefficient as a function of relative wave height and wave steepness. The drag coefficient demonstrated a stronger relationship with the Keulegan–Carpenter number than the Reynolds number. The linear relationship be-tween relative depth and Manning’s n was stronger than that between Manning’s n and either relative wave height or wave steep

27 Sep 2022

Analytic Methods for Establishing Restoration Trajectories

Abstract: This special report identifies metrics (standard and novel) and analytic approaches to developing trajectories and then describes the conceptual process of using those metrics and approaches to develop restoration trajectories to inform adaptive management in salt-marsh systems. We identify the composite time series trajectory (CTST) approach, in which metrics are measured from restoration sites of different ages within a small spatial range, and the retrospective single-site trajectory (RSST) approach, in which the same restoration metrics are measured over time at one restoration site. In all, we assessed the metrics of 39 studies of salt-marsh restoration in the United States between 1991 and 2019.

26 Sep 2022

Occurrence of Silver, Bighead, and Black Carp in Waters Managed by the US Army Corps of Engineers

Abstract: This technical report (TR) documents the distribution of Invasive Carp - Silver Carp (Hypophthalmichthys molitrix), Bighead Carp (Hypophthalmichthys nobilis), and Black Carp (Mylopharyngodon piceus) in US Army Corps of Engineers (USACE) managed waters. Invasive carp were introduced into the US nearly half a century ago. As they spread across the US, they compete with and consume native species and Silver Carp jumping behavior reduces recreational use. The USACE is responsible for management of waterbodies at more than 440 projects. Information on these projects including the presence of Invasive Carp is reported in the USACE Operations and Maintenance Business Information Link (OMBIL) database. To supplement the Invasive Carp information from OMBIL, 47 online ichthyology collection and observation databases were searched; 18 had information on Invasive Carp locations. Combining the collection, observation and OMBIL reporting information, 82 USACE projects in 19 districts in 6 of 8 divisions have Silver/Bighead Carp and 19 projects in 9 districts and 3 divisions have Black Carp. Understanding the distribution of Invasive Carp is important to enable managers to be pro-active: planning control efforts, posting informational signs, instituting live bait restrictions, and thus reducing the chances of species introduction or limiting species impact.

23 Sep 2022

Literature Review: Macrohabitat Metrics to Identify Presence of Chiroptera on the Landscape in the United States

Abstract: This special report reviews current scientific literature to identify the most commonly cited metrics used to describe the macrohabitat criteria important for Chiroptera presence in the United States. The review evaluates 69 scientific articles from 1994 to 2018. The most commonly cited metrics were divided into four main categories: tree-species-level metrics, landscape-level metrics, distance metrics, and topographic and atmospheric metrics. Of all metrics found, the top six most common metrics noted across all articles were percent canopy cover, diameter at breast height (DBH), forest type, distance to water, distance to roads or other urban features, and tree density. In addition, 27 of the 47 (57%) bat species located within the United States were represented. These metrics provide important insight into the regional or national species-level distribution and assist with modeling the relationship between species distribution and habitat change.

23 Sep 2022

Qualification of Hanna Instruments HI9829 for the Environmental Toolkit for Expeditionary Operations

Abstract: A new, commercially available, field-portable water sensor was evaluated for efficacy during operation and compatibility with current Environmental Toolkit for Expeditionary Operations (ETEO) software. The ETEO provides sensors to Soldiers to rapidly identify and quantify environmental contamination in soil, air, and water at potential new base sites during initial reconnaissance to ensure safety and minimize unnecessary remediation efforts by the Army. In addition to streamlined environmental baseline survey (EBS) reporting, the ETEO can provide rapid analysis of potential environmental contamination to support various Military applications. The Hanna Instruments HI9829 multiparameter water meter was selected following a survey of commercial off-the-shelf (COTS) technologies and analyzed by researchers from the US Army Engineer Research and Development Center (ERDC) for inclusion in the ETEO design since it can rapidly and accurately measure 14 different properties. Usability tests were conducted with researchers unfamiliar with the technology, and a set of standard operating procedures (SOPs) were developed to operate the device. The software for the tool was successfully integrated into the ETEO system for rapid data analysis. The HI9829 has been demonstrated in various scenarios at ERDC and other locations; including Ft. Leonard Wood, MO, at which several visitors reviewed the operation of the equipment and other ETEO technologies. The Thermo Scientific Gemini, another sensor, which can detect organic constituents in various matrices via Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy was also investigated but eliminated from the ETEO design as it could not adequately detect a Military-relevant compound in an environmental matrix. Regardless, the addition of the HI9829 provides water quality monitoring to the ETEO design and greatly improves its capability to address various applications.

19 Sep 2022

Systematic Beneficial Use of Dredged Sediments: Matching Sediment Needs with Dredging Requirements

PURPOSE: This technical note (TN) will outline a framework to identify beneficial and cost-effective coastal beneficial use of dredged sediment (BUDS) projects. Creation of a BUDS framework that can be applied at scale will promote sustainable BUDS practices, facilitating the delivery of flood risk management, social, and environmental benefits while still fulfilling the US Army Corps of Engineers (USACE) navigation mission. This proactive forecasting approach uses multi-criteria decision analysis (MCDA) and optimization tools to balance tradeoffs between navigation dredging and BUDS goals over project-scale timespans. The proposed framework utilizes available tools to quantify ecological system evolution and current and future dredging needs to develop a systems-level approach to BUDS. Required data include current and future information on (1) existing and planned natural and created aquatic ecological systems, which may include natural and nature-based features (NNBFs), (2) dredging requirements and costs, and (3) aquatic system physical and environmental data.

16 Sep 2022

Flowering Rush Control in Hydrodynamic Systems: Part 1: Water Exchange Processes

Abstract: In 2018, field trials evaluated water-exchange processes using rhodamine WT dye to provide guidance on the effective management of flowering rush (Butomus umbellatus L.) at McNary Dam and Reservoir (Wallula Lake, 15,700 ha). Additional evaluations determined the effectiveness of BubbleTubing (hereafter referred to as bubble curtain) at reducing water exchange within potential flowering rush treatment areas. Dye readings were collected from multiple sampling points at specific time intervals until a dye half-life could be determined. Whole-plot dye half-lives at sites without bubble curtain ranged 0.56–6.7 h. In slower water-exchange sites (≥2.6 h dye half-life), the herbicide diquat should have a sufficient contact time to significantly reduce flowering rush aboveground biomass. Other sites demonstrated very rapid water exchange (<1.5 h dye half-life), likely too rapid to effectively control flowering rush using chemical treatments without the use of a barrier or curtain to slow water exchange. At one site, the use of the bubble curtain increased the dye half-life from 3.8 h with no curtain to 7.6 and 7.1 h with a bubble curtain. The bubble curtain’s ability to slow water exchange will provide improved chemical control and increase the potential for other chemical products to be effectively used.

15 Sep 2022

Microbial Dynamics of a Fluidized Bed Bioreactor Treating Perchlorate in Groundwater

Abstract: Optimization of operation and performance of the groundwater treatment system regarding perchlorate removal at Longhorn Army Ammunition Plant (LHAAP) is dependent on specific conditions within the reactor and the larger groundwater treatment process. This study evaluated the microbial community compositions within the plant during periods of adequate perchlorate degradation, sub-adequate perchlorate degradation, and non-operating conditions. Factors affecting the performance of the LHAAP ground water treatment system (GWTS) perchlorate de-grading fluidized bed reactor (FBR) are identified and discussed. Isolation of the FBR from naturally occurring microbial populations in the groundwater was the most significant factor reducing system effectiveness. The microbial population within the FBR is highly susceptible to system upsets, which leads to declining diversity within the reactor. As designed, the system operates for extended periods without the desired perchlorate removal without intervention such as a seed inoculant. A range of modifications and the operation of the system are identified to increase the effectiveness of perchlorate removal at LHAAP.

15 Sep 2022

Informing the Community Engagement Framework for Natural and Nature-based Projects: An Annotated Review of Leading Stakeholder and Community Engagement Practices

Abstract: In its infrastructure development work, the US Army Corps of Engineers (USACE) engages and collaborates with numerous local, state, and national stakeholders. Projects incorporating innovative approaches, such as beneficial use (BU) of dredged materials and other natural and nature-based features (NNBF), are often not well-understood by stakeholders, including those at the community level. This often results in conflicts and project delays. By sponsoring the development of a Community Engagement Framework, the Dredging Operations and Environmental Research (DOER) program hopes to systematically improve how project teams design, conduct, and measure effective community engagement on infrastructure projects. The purpose of this focused Review was to assesses leading stakeholder and community engagement practices that reflect the state of practice of stakeholder engagement within USACE, and by other leading organizations in the US and internationally, to inform development of the Community Engagement Framework. While the resulting Framework will be particularly well-suited for community engagement on projects incorporating BU and other NNBF, it will be applicable to a broad range of USACE Civil Works’ initiatives where effective stakeholder engagement is critical to project success. The assessment showed the practice of stakeholder engagement has evolved significantly over the past 30 years, with much more focus today on ensuring that engagement processes are purposeful, meaningful, collaborative, and inclusive - reflecting stakeholders’ desire to participate in co-creating sustainable solutions that produce environmental, economic, and social benefits. This, and other key findings, are informing development of the Community Engagement Framework which is scalable and adaptable to a broad range of projects across the USACE missions.