7 May 2026

An All-Hazards Return on Investment (ROI) Model to Evaluate U.S. Army Installation Resilient Strategies

Abstract: The paper describes our project to develop, verify, and deploy an All-Hazards Return of Investment (ROI) model for the U.S. Army Engineer Research and Development Center (ERDC) to provide army installations with a decision support tool for evaluating strategies to make existing installation facilities more resilient. The need for increased resilience to extreme weather caused by climate change was required by U.S. code and DoD guidance, as well as an army strategic plan that stipulated an ROI model to evaluate relevant resilient strategies. During the project, the ERDC integrated the University of Arkansas designed model into a new army installation planning tool and expanded the scope to evaluate resilient options from climate to all hazards. Our methodology included research on policy, data sources, resilient options, and analytical techniques, along with stakeholder interviews and weekly meetings with installation planning tool developers. The ROI model uses standard risk analysis and engineering economics terms and analyzes potential installation hazards and resilient strategies using data in the installation planning tool. The ROI model calculates the expected net present cost without the resilient strategy, the expected net present cost with the resilient strategy, and ROI for each resilient strategy. The minimum viable product ROI model was formulated mathematically, coded in Python, verified using hazard scenarios, and provided to the ERDC for implementation.

6 May 2026

Economic Valuation and Natural Resource Damage Assessment Methods at Myakka River State Park, Florida

Abstract: The growing population and distribution of invasive wild pigs across vulnerable ecological communities has emerged as a significant issue, and there is not a standardized ecological-economic framework to precisely measure and value the impact of wild pigs to natural resources. The FY24 research presented here is year four of a 4-year research plan to develop a user-friendly ecological-economic framework for rapid assessment and valuation of wild pig damage to wetlands. Building off the findings from research conducted at Somerville Lake, Texas, and Richard K. Yancey Wildlife Management Area, Louisiana, this FY24 research took place at Myakka River State Park, Florida. Research objectives for FY24 included adapting the ecological-economic framework to a different landscape type, refining and broadening the artificial intelligence–based economic valuation approach by valuing a variety of natural communities, and improving the setup of the before-after-control-impact study design estimating damage reduction after a targeted control effort. Across the study area, we estimated that the benefits provided by the natural communities lost to wild pigs over a 1-year period were $273,525 (80% confidence interval: $72.684 and $920.883), and an aerial gunning control effort produced an estimated 685% return on investment in avoided losses 4 weeks postmanagement.

5 May 2026

Uptake and Elimination of Per-and Polyfluoroalkyl Substances in Earthworms Exposed to Spiked Artificial Soil or Aqueous Medium

Abstract: We investigated the accumulation of per-and polyfluoroalkyl substances (PFAS) in earthworms (Eisenia andrei). Uptake kinetics and bioaccumulation factors (BAFs) were determined using a mixture of 16 PFAS by exposing earthworms to spiked artificial soil for up to 28 days. Two treatments were used, with the low treatment targeting environmentally relevant concentrations. The concentrations of PFAS remained relatively unchanged during the exposures and statistically significant rates of uptake were estimated for most individual PFAS. For the 0.01 mg/kg treatment (target concentration of each PFAS), steady state was reached for all PFAS except perfluoroheptanoic acid, perfluorohexanesulfonic acid (PFHxS), perfluorooctanesulfonic acid (PFOS), perfluorotetradecanoic acid (PFTeDA), and perfluorotridecanoic acid. For the 0.01 mg/kg treatment, bioaccumulation factors (BAF; kg/kg-dry wt) ranged from 4–49 for most PFAS but were higher for PFHxS (72), PFTeDA (271), and perfluoroundecanoic acid (299). Organic carbon–normalized BAFs were within the range of published values. The BAF values increased with increasing length of the alkyl chain for perfluoroalkyl carboxylic acids (PFCAs), but not for perfluoroalkyl sulfonic acids (PFSAs). Uptake rates and BAFs were lower for the 1 mg/kg treatment, typically by over one order of magnitude, likely because of sublethal physiological impairment. Fast and steep decreases in tissue concentrations of PFAS occurred when earthworms were transferred to clean soil, even for long chain PFAS, agreeing overall with previous reports. However, measured elimination rates were faster than predicted from the uptake experiments and the causes remain unknown. Bioaccumulation of PFAS was also investigated in exposures to aqueous medium for up to 7 days to derive bioconcentration factors (BCFs). Comparison of BCFs and BAFs suggests that uptake from soil may have higher relevance than dermal uptake from porewater for long-chain PFCAs and PFSAs.

5 May 2026

Carrying Capacity in Human-Environment Interactions: A Systematic Review

Abstract: The concept of carrying capacity has been applied broadly to various biological and social contexts. This article presents a systematic review of the carrying capacity literature as applied to human-occupied environments. The review evaluates underlying approaches and methods and explores the utility and limitations of the concept’s applications. Prominent tools and approaches identified include evaluation index systems, ecological footprint analysis, the Cifuentes method, multi-objective optimization, system dynamics, fuzzy mathematics, and remote sensing and geographical information systems. Our findings indicate that, despite its origins, carrying capacity research is rarely concerned with the survival of human communities; instead, it is often invoked to understand the implications of human population growth and urbanization on living and sufficiency standards. The majority of identified carrying capacity studies did not define a strict upper boundary, demonstrating the utility of carrying capacity as a rhetorical strategy to galvanize action before system degradation eliminates options. The concept of carrying capacity, when applied to human-managed and constructed environments, increasingly reflects socioeconomic factors and quality of life considerations, underscoring subjective social constraints and societal tolerance levels rather than physical limitations on population survival.

5 May 2026

Behavioral Responses of Silver Carp to Underwater Acoustic Deterrent Sounds

Abstract: Invasive carps continue to spread across the Mississippi River basin, posing significant ecological risk. Identifying technologies to slow their dispersal is critical. The use of sound has been proposed as a method to modify the behavior of Silver Carp Hypophthalmichthys molitrix, offering a nonstructural deterrent strategy. Silver Carp implanted with acoustic transmitters were released into earthen ponds equipped with telemetry arrays. The fish were exposed to a 30-min playback of three underwater sounds (chirp saw, chirp square, and 100- hp boat motor). Movement trajectories were analyzed using a two-state hidden Markov model to estimate the effects of environmental and experimental variables on fish behavior. The results of the hidden Markov model supported two behavioral states. State 1 was characterized by longer step lengths and greater directional persistence in turning angle, indicative of heighted activity. State 2 was defined by shorter step lengths and less directional persistence, suggesting reduced activity. Silver Carp that were exposed to the chirp square sound had an increased likelihood of entering state 1, whereas the 100-hp boat motor sound promoted transitions to state 2. Underwater sounds distinctly influenced the movement of Silver Carp in earthen ponds. The chirp square sound elicited heightened activity levels, demonstrating potential for use in acoustic deterrent applications. However, the response of Silver Carp to these sounds may be influenced by the size of the study environment or the absence of natural drivers of fish behavior, such as food or reproduction. This study contributes to the development of nonstructural, species-specific deterrent systems by identifying sounds that influence the behavior of invasive carps. The application of sound- based methods may play a critical role in integrated pest management strategies for invasive carps, potentially limiting their spread while minimizing effects on native species.

5 May 2026

Designing Sortable Guilds for Multispecies Selective Fish Passage

Abstract: The importance of connectivity for freshwater organisms is widely recognised, yet in-stream barriers associated with population declines and increased risk of extinction remain globally ubiquitous. Despite their negative consequences, these barriers can protect aquatic communities by limiting the spread of invasive species, leading to conflicting management goals in some regions. Selective fish passage is a solution for the conflicting goals of passing native, desirable species while restricting the spread of invasives. Approaches that can target groups of species sharing similar attributes (i.e. guilds) are likely to be more efficient than those that target species individually, particularly in taxonomically diverse systems. We explored the guild structure of 220 Great Lakes freshwater fishes based on morphological, phenological, physiological and behavioural attributes associated with passage and movement. We identified five distinct guilds as well as the attributes most important for defining these groupings: maximum total length, trophic level, relative eye size, spawning temperature, spawning season, presence/absence of ampullary electroreceptors and the presence/absence of hearing specialisations. The approaches outlined in this work can be generalised to enhance selective fish passage in aquatic ecosystems worldwide.

4 May 2026

Insight into the Photocatalytic Degradation Mechanism for “Forever Chemicals” PFNA by Reduced Graphene Oxide/WO3 Nanoflower Heterostructures

Abstract: Water contamination with “forever chemicals” like per- and polyfluoroalkyl substances (PFAS) poses significant toxicity to the environment. Since they are the most persistent synthetic chemicals that hardly degrade in the natural environment and are carcinogenic to humans, there is an urgent need to discover novel processes for destroying PFAS. Herein, we report on the design of a reduced graphene oxide (r-GO)/WO3 nanoflower (WO3-NF)-based heterostructure for harnessing 365 nm light-driven photocatalytic oxidation and reduction process toward the photocatalytic degradation of perfluorononanoic acid (PFNA). Moreover, reported data reveal that using an r-GO/WO3-NF heterostructure photocatalyst, 100% PFNA degradation and 14% defluorination can be achieved in the presence of isopropyl alcohol as the hydroxy radical (•OH) quencher or glucose as a hot hole (h+) quencher after exposure to 365 nm light for 22 h. A reported mechanistic study shows synergistic oxidation and reduction processes are vital for the complete degradation of PFNA, where the hydrated electron (eaq−) plays a key role as a reducing agent and h+ and •OH act as oxidation agents. Furthermore, the photocatalytic destruction mechanism study indicates that chain shortening via C−C bond breaking and defluorination via C−F bond breaking are major pathways for PFNA degradation. A wavelength-dependent study shows that only 22% degradation can be achieved after exposure to 532 nm light for 22 h, which is due to the lack of the formation of hydrated electrons (eaq−). The current study sheds light on the construction of the r-GO/WO3 NF heterojunction for the highly efficient degradation of PFAS.

23 Apr 2026

Towards an Improved Language for River Data Analysis: Demonstration for the Highly-Regulated Ohio River Basin

Abstract: We present the Network Analysis and Data Integration (NADI) System for extracting, organizing, analyzing, and visualizing river data with upstream/downstream relationships. The NADI System consists of a Geographical Information System (GIS) tool that uses spatial methods to generate the network, and a Domain Specific Language (DSL) that provides a concise and intuitive syntax for data analysis and is extensible through a plugin system. We demonstrate the capabilities of NADI using a case study of the Ohio River basin, showing it to be well-suited for large-scale metadata analysis based on river connections. The result of the case study shows that approximately half of the USGS streamflow gages in the Ohio Basin were constructed after dam(s) upstream, and only 35% of the gages remain without any dams upstream. These unaffected gages only account for 1.2% of the measured streamflow, showing the scarcity of natural streamflow data.

23 Apr 2026

Development of an Agnostic Reservoir Model to Explore Wildfire Impact on Water Quality

Abstract: Despite the growing global concern surrounding the havoc caused by wildfires, there are still prominent gaps in knowledge regarding fire effects on nearby waterways. An agnostic CE-QUAL-W2 model was developed to look at the impact of wildfires on reservoir water quality, with a focus on harmful algal blooms. The model was informed using ten years of meteorological data from sites in the Pacific Northwest, United States. Wildfire scenarios were generated (one each for May, June, July, August, and September) using changes in temperature, total suspended solids, nutrients, dissolved oxygen, organic matter, and solar radiation typical of wildfires, informed via literature review. Harmful algal blooms showed the most sensitivity to fires that occurred prior to the growing season, likely due to the influx of phosphate accumulating in the system prior to growth. However, accumulation of nutrients for fires after the growing season showed impacts on blooms the following year. Increases in total dissolved solids during the fire could potentially lead to delays in initial bloom timing due to temporary light limitation. Results from the model runs indicate that wildfires can impact reservoir water quality and bloom dynamics not only immediately, but for months to years following a wildfire.

22 Apr 2026

An Interdisciplinary Overview of Levee Setback Benefits: Supporting Spatial Planning and Implementation of Riverine Nature-Based Solutions

Abstract: Nature-based solutions are increasingly recognized as multi-benefit strategies for addressing the critical sustainability challenges of the Anthropocene, including the climate emergency and biodiversity crisis. Mainstreaming NbS in professional practice requires strategic, landscape-level planning integrating multiple sources of benefits and their synergies and trade-offs. Levee setbacks (LS) are among the best-studied riverine NbS with recognized benefits for flood risk management, drought resilience, water quality management, recreational opportunities, and ecological restoration for biodiversity. Although awareness of the multifarious benefits of LS as forms of Natural Capital is growing, implementation remains ad-hoc and opportunistic. To address this critical implementation gap for one major example of NbS, we review and synthesize literature across diverse disciplines to provide an overview of the primary social, economic, and ecological mechanisms that affect the co-benefit delivery of LS projects. Next, to make this information relevant to NbS practitioners, we link these mechanisms to spatial metrics that can be used to approximate the relative magnitude of project benefits and costs across these mechanisms. Finally, we highlight examples of key synergies and trade-offs among benefits that should be considered for LS planning. This synthetic approach is intended to familiarize readers with the diverse potential benefits of LS, and provide an understanding of how to select and prioritize potential sites for further study and implementation. Synergies and trade-offs among important benefit drivers abound, and social equity concerns will be paramount in ensuring the successful implementation of LS and other NbS in the future.