22 Aug 2025

Local Integrated-Technology Energy System to Meet Operational Needs (LITES ON) Project

Abstract: The ability to reliably charge battery systems, whether for vehicles, mission support equipment, or stationary purposes, is especially important in remote and cold regions. The US Army Cold Regions Research and Engineering Laboratory (CRREL) project team evaluated and documented the performance of potential photovoltaic (PV) battery charging configurations (e.g., controller component) for use in such regions, especially as backup alternatives to other grid-connected charging stations that support Army installations, with a unique focus on the power electronics components of the system. In addition to its potential to support building energy resilience, this work complements other work that considers electrification of the DoD fleet of vehicles and the needed grid-connected infrastructure. This work adds to the growing information available on lithium ion (Li-ion) battery performance in cold regions by monitoring the battery performance as part of the test configuration. The results help better inform design and performance requirements needed for cold regions applications as well as the acquisition of such systems.

22 Aug 2025

Continuous Real-Time Acoustic Monitoring of Endangered Bird Species in Hawai‛i

Abstract: The decline of endemic bird species in Hawai‘i requires innovative conservation measures enabled by passive acoustic monitoring (PAM). This paper describes a novel real-time PAM system used in the Pōhakuloa Training Area (PTA) to reduce wildlife collisions and minimize disruptions to military operations while ensuring the protection of endangered bird species such as the Nēnē and ‘Akē‘akē. The system is based on the BirdNET algorithm and was evaluated with over 16,000 soundscape recordings from Hawai‘i. The results show that the model version HI V2.0, based on BirdNET and specifically adapted to Hawaiian bird species, showed the clearest separation between true and false positive detections (average precision 49% to 52%), although this difference was not statistically significant. However, accuracy varied considerably between species and locations, emphasizing the need to adapt the models to the specific conditions of use. A novel web application allows immediate visualization of the predicted bird species, facilitating the implementation of conservation measures. The three acoustic monitoring units installed at the PTA in January 2023 demonstrate the system’s potential for continuous monitoring and protection of Hawaiian endangered bird species.

22 Aug 2025

Cracking the Code: Linking Good Modeling and Coding Practices for New Ecological Modelers

Abstract: Good modeling practices are essential for producing reliable and reproducible ecological models. Inherent to good modeling practices are fundamental coding and documentation skills, which not only implement the desired modeling capabilities but also clearly outline the goals, methods, and components of a model necessary to reproduce desired results. Coding represents a significant barrier for entry into ecological modeling, since most ecologists have not had formal training in computer science or software development. While software packages do exist that facilitate model development, we have observed that newer modelers still struggle with developing good coding practice throughout the modeling process. During a series of agent-based modeling short-courses and full semester graduate courses, both taught in NetLogo, we identified some common challenges encountered by graduate students and environmental professionals as they learn to code an ecological model, many for the first time. We were able to categorize and provide examples of the main challenges and obstacles, which fell into three main groups that follow the steps of good modeling practice: problem scoping and conceptualization, formulation, and evaluation. We then provide guidance on how to overcome these obstacles while developing good coding and modeling practices that will result in more scientifically defensible models.

20 Aug 2025

Parameterized Statistical Distributions of Unique Origin-Destination Pairs for Major Waterborne Commodity Groups

Abstract: Modeling the spatiotemporal aspects of freight movements within a distributed network is crucial to forecasting transportation infrastructure needs, prioritizing investments, and estimating emissions. Commodity flow patterns and trends along the inland waterway transportation system are significant because of their importance for the economy, in line with priorities of the US Committee on the Marine Transportation System. Analyzing these inland waterway flows better informs multimodal freight transportation modeling. This exploratory research uncovers, describes, and summarizes patterns and trends of the US waterway transportation system by mining waterborne freight data. The purpose of this work is to identify parameterized statistical distributions that describe the relative dispersion of unique waterborne Origin-Destination (OD) pairs when sorted high to low by annual freight tonnage. Best-fit statistical distributions and associated parameters are identified for the leading commodities transported on waterways, and an 11-year time-series analysis of commodity-specific distribution parameters provide their evolution across time. Results show that the power law best explains the distribution of ranked ODs by tonnage for seven of the twelve commodities analyzed. The root-mean-square error (RMSE) of any given commodity modeled is less than 1%. These results provide insights into the underlying behavior of inland waterway freight transportation.

20 Aug 2025

Examining the Impact of the 2007 Zaca Fire on the Long-Term Hydrological Recovery of the Santa Cruz Creek Watershed in Southern California

Abstract: This study focuses on the Santa Cruz Creek watershed in Southern California, an area severely impacted by the 2007 Zaca Fire. The region is representative of wildfire-prone Mediterranean-climate catchments. We assess long-term post-fire hydrological recovery using a novel dual approach: (1) simulating 16 storm events over a 23-year period to evaluate pre-fire, post-fire, and recovery conditions, and (2) directly comparing two similar storm events—one pre-fire and one during recovery—to isolate changes in watershed response. Hydrological modeling employed HEC-HMS with the Deficit and Constant Loss Method, the ModClark Transform Model, and the Linear Reservoir Baseflow Model. Remote sensing data, including Enhanced Vegetation Index and SERVES Soil Moisture, enhanced modeling and analysis. Vegetation cover, soil moisture, and several watershed parameters show substantial recovery after five years. EVI reached 84 % of pre-fire values, while initial soil moisture deficit, time of concentration, and storage coefficient each recovered to roughly 70 %. Fast baseflow exceeded pre-fire levels at 143 %, but slow baseflow declined to 20 %. Peak discharge and direct runoff volume declined from post-fire highs of 173 % and 136 % to 125 % and 84 % of pre-fire levels, respectively. Although vegetative conditions stabilize, watershed hydrology remains altered.

20 Aug 2025

Bioturbation Increases Time Averaging Despite Promoting Shell Disintegration: A Test Using Anthropogenic Gradients in Sediment Accumulation and Burrowing on the Southern California Shelf

Abstract: Bioturbation increases time averaging of young and old shells within the entire mixed layer and accelerating the burial of shells into a sequestration zone. Bioirrigation by oxygenated pore-water promotes carbonate dissolution in the TAZ, and biomixing itself can mill shells weakened by dissolution or microbial maceration, and/or expose them to damage at the sediment–water interface. We fit transition rate matrices to bivalve age–frequency distributions from four sediment cores to assess the competing effects of bioturbation on disintegration and time averaging. Disintegration covaries positively with mixing at all four sites. Mixing and disintegration rates decline abruptly at the base of the 20- to 40-cm-thick, age-homogenized surface mixed layer at the three well-bioturbated sites. In contrast, they are very low in the upper 25 cm at an effluent site with legacy sediment toxicity. Assemblages formed during maximum wastewater emissions vary strongly in time averaging. Thus, even though disintegration rates covary positively with mixing rates, reducing postmortem shell survival, bioturbation has the net effect of increasing the time averaging of skeletal remains on this warm-temperate siliciclastic shelf.

20 Aug 2025

Coastal Sand Dunes: A Review of Management Strategies for Dune Stabilization

Abstract: The primary objective of this technical note is to provide a US-centric review on historic and current management approaches for dune stabilization efforts. This includes methods for promoting dune formation via natural aeolian processes, as well as more hands-on management approaches, including hybrid dune construction.

20 Aug 2025

SandSnap Filtering Techniques

Abstract: The aim of this Coastal and Hydraulics Laboratory Special Report is to elucidate the new SandSnap image filters. These SandSnap filters distinguish between high-quality and poor-quality images and enhance accuracy in high-quality images. To achieve this goal, a dataset of 5,000 photos was created and curated for this endeavor. Images were collected that had varying levels of focus, sedimentological conditions, foreign objects present, distances from the sediment bed, coin types, and geographic locations. This dataset was used to train multiple quality control check models and uncover beneficial correlations. Additionally, an existing dataset of high-quality images was analyzed using various filtering techniques to highlight key features, leading to higher-accuracy scores. Using the findings from both the high-quality and poor-quality datasets, SandSnap was updated to increase usability and efficiently identify images that may lead to poor results. This ensures that user results can be calculated in less than a minute, emphasizing the commitment to maintaining a fast and responsive model.

20 Aug 2025

Trade-offs Between Field and Remote Geomorphic Monitoring of Coastal Marsh Restoration Sites

Abstract: Coastal marsh restoration presents geomorphic monitoring challenges because these sites are often remote or inaccessible, and time and financial resources for field data may be limited. Yet, elevation and shoreline characteristics contribute to the overall health and longevity of coastal marshes. The expansion of Uncrewed Aircraft System (UAS) technology and new satellite platforms offer opportunities to complement ground-based geomorphic monitoring and overcome the challenges of traditional field methods. Here, we compare field-based and remote-sensing approaches to monitor two restored coastal wetlands in Louisiana. At Spanish Pass, methods for measuring site elevation, shoreline position, and shoreline geomorphic types were compared. Ground surveys strongly correlated with UAS-lidar digital elevation model (DEM) elevations (R2 = 0.97. UAS and satellite imagery were accurate to within 3 meters of field-shoreline positions, and UAS-lidar-derived shorelines had the lowest error. At LaBranche, UAS-lidar DEM data were paired with airborne lidar and legacy ground surveys to track temporal changes in elevation, indicating minimal elevation change. The study demonstrates the accuracy and utility of satellite and UAS remote sensing for monitoring shoreline positions and elevations but notes that shoreline classifications could be improved with additional quantification. These findings help practitioners assess the trade-offs and benefits of various monitoring methods.

19 Aug 2025

Do Land Models Miss Key Soil Hydrological Processes Controlling Soil Moisture Memory?

Abstract: Soil moisture memory is critical for understanding climatic, hydrological, and ecosystem interactions. Most land surface models overestimate surface soil moisture and its persistency, sustaining spuriously large soil surface evaporation during dry-down periods. Do LSMs miss or misrepresent key hydrological processes controlling SMM? We used Noah-MP with advanced hydrology that represents preferential flow and surface ponding and provides optional schemes of soil hydraulics. Effects were tested, which are generally missed by LSMs in SMM. We compare SMMs computed from various Noah-MP configurations against that derived from the Soil Moisture Active Passive L3 soil moisture and in situ measurements from the International Soil Moisture Network between 2015 to 2019 over the contiguous US. Results suggest soil hydraulics plays a dominant role and the Van Genuchten hydraulic scheme reduces overestimation of the long-term surface SMM produced by the Brooks–Corey scheme; explicitly representing surface ponding enhances SMM for the surface layer and the root zone; and representing preferential flow improves overall representation of soil moisture dynamics. The combination of these missing schemes can significantly improve the long-term memory overestimation and short-term memory underestimation issues in LSMs. LSMs for use in seasonal-to-subseasonal climate prediction should, at least, adopt the Van Genuchten hydraulic scheme.