16 Jun 2025

Estuarine Dams and Weirs: Global Analysis and Synthesis

Abstract: Estuarine dams and weirs are constructed in estuaries for blocking the salt intrusion, securing freshwater, and stabilizing upstream water levels. While they can provide many social benefits, they also alter physical and sedimentary processes. To address this, we perform and extensive remote sensing and literature analysis. Remote sensing was conducted based on a global river database of 1531 rivers representing the largest rivers cumulatively draining 85 % of the landmass discharging into the global ocean. It was found that 9.7 % of global estuaries and deltas are currently affected by estuarine dams or weirs acting as the upstream limit of salt, tide, or storm surge intrusion. Most estuarine dams and weirs are located at x = 0–100 km inland from the mouth and their discharge intervals can be continuous. They are found most in river mouths which are wave-dominated followed by tide-dominated and then river-dominated. They can cause significant changes to the quantity and timing of freshwater discharge, tides, stratification, turbidity, sedimentation, oxygen conditions, phytoplankton blooms, and fish migration. We propose a conceptual model for physical and geomorphological change in mixed wave- and river-dominated and tide-dominated estuaries with estuarine dams.

16 Jun 2025

Enhancing Resilience: Integrating Future Flood Modeling and Socio-Economic Analysis in the Face of Climate Change Impacts

Abstract: As climate change intensifies, floods will become more severe in some areas with geographic variation, necessitating governments implementing systems providing information for climate adaptation. We aimed to develop a methodology identifying areas at an increased risk. In this study, 100-year recurrence interval flood extents and depths were estimated using an ensemble of six independent Coupled Model Intercomparison Project Phase 6 climate models for a past and future period under the highest-emissions climate scenario. The flood inundation results were related to social vulnerability for two study areas in the Mississippi River Basin. To identify at-risk areas, the relationship between the spatial distribution of flood depths and vulnerability was assessed. Finally, an analysis of current and future damages on infrastructure from flooding on residential housing to determine whether damages correlated with higher vulnerability areas. Results show flood extents and depths are increasing in the future, ranging from an increase of 6 to 76 km2 in extent. A statistically significant relationship between spatial clusters of flooding and of vulnerability was found. Overall, a framework was established to holistically understand the hydrologic and socioeconomic impacts of climate change, and a methodology was developed for allocating resources at the local scale.

13 Jun 2025

User Guidelines on Catchment Post-Wildfire Hydrological Modeling

Abstract: Wildfires significantly alter watershed hydrology by increasing runoff due to reduced infiltration from soil-water repellency. To predict long-term wildfire impacts, a coupled framework was developed to simulate postfire changes in soil hydraulic properties, infiltration, and hydrological response. This framework integrates Wildfire-Induced Soil Hydraulic (WISH) Factors with a Soil-Moisture Threshold (SMT) formulation in the Green and Ampt infiltration model, representing reduced infiltration due to water repellency. Postfire inputs, including burn severity, soil type, and land use, are formatted for the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model to ensure realistic hydrological simulations. The approach was applied to the 41.7 km² Upper Arroyo Seco watershed in northeast Los Angeles County, where 95% of the area was burned during the August 2009 Station Fire. Hydrological simulations effectively captured increased water repellency and excess runoff following postfire rainfall, demonstrating the model’s ability to represent wildfire-induced watershed changes and improve postfire hydrological assessments.

11 Jun 2025

Prediction of Waterborne Freight Activity with Automatic Identification System Using Machine Learning

Abstract: This paper addresses latency issues related to publicly available port-level commodity tonnage reports. Predicting commodity tonnage at the port-level, near real time vessel tracking data is used with historical WCS with a machine learning model. Commodity throughput is derived from WCS data which is released publicly approximately two years after collection. This latency presents a challenge for short-term planning and other operational uses. This study leverages near real time vessel tracking data from the AIS data set. LSTM, TCN, and TFT machine learning models are developed using the features extracted from AIS and the historical WCS data. The output of the model is the prediction of the quarterly volume of commodities at port terminals for four quarters in the future. Uncategorized and Categorized models were developed. The uncategorized outperformed the categorized based on the Mean Absolute Percentage Error. The uncategorized LSTM model has the highest accuracy. Results show the model has higher accuracy for port terminals that handle a specific type of vessel, compared to the port terminals handling more than one vessel type. The application of the model enables port authorities and stakeholders to make short-term capacity expansion and infrastructure investment decisions based on commodity volume.

4 Jun 2025

Floridan Aquifer System (FAS) Aquifer Material Collection and Screening: Investigating Arsenic Fate and Transport Under Lab-Simulated Aquifer Storage and Recovery (ASR) Conditions in the FAS—Task A Report

Abstract: The US Army Engineer Research Development Center is leading a laboratory study to quantify arsenic release that could occur during large-scale aquifer storage and recovery (ASR) operations in the anoxic Floridan Aquifer System (FAS). FAS materials containing arsenic must be collected and preserved under anoxic conditions to complete the laboratory study. This report describes collection, preservation, and initial characterization results of FAS material collected. Analysis of water surrounding the FAS material during storage detected some arsenic, suggesting arsenic presence in the solids. In-depth characterization of a single sample confirmed storage conditions were anoxic; no arsenic was detected in surface scrapings collected from the sample solids. Initial characterization results suggested FAS materials collected were suitable for use in the planned laboratory study and that storage methods were suitable for preserving collected materials.

3 Jun 2025

Development and Validation of NOAA’s 20-Year Global Wave Ensemble Reforecast

Abstract: A 20-yr wave reforecast was generated based on the NOAA Global Ensemble Forecast System, version 12. It was produced using the same setup as the NCEP’s operational GEFSv12 wave component. The reforecast comprises five members with 1 cycle per day and a forecast range of 16 days. Once a week, it expands to 35 days and 11 members. This paper describes the development of the wave ensemble reforecast, focusing on validation against buoys and altimeters. The statistical analyses demonstrated very good performance in the short range for significant wave height, with correlation coefficients of 0.95–0.96 on day 1 and between 0.86 and 0.88 within week 1, along with bias close to zero. After day 10, correlation coefficients fall below 0.70. The degradation of predictability and the increase in scatter errors predominantly occur in the forecast lead time between days 4 and 10, in terms of the ensemble mean and individual members, including the control. For week 2 and beyond, a probabilistic spatiotemporal analysis of the ensemble space provides useful forecast guidance. Our results provide a framework for expanding the usefulness of wave ensemble data in operational forecasting applications.

3 Jun 2025

Development of a Wave Model Component in the First Coupled Global Ensemble Forecast System at NOAA

Abstract: We describe the development of the wave component in the first global-scale coupled operational forecast system using the Unified Forecasting System at NOAA, part of the U.S. National Weather Service operational forecasting suite. The operational implementation of the atmosphere–wave coupled Global Ensemble Forecast System, version 12, was a critical step in NOAA’s transition to the broader community-based UFS framework. GEFSv12 represents a significant advancement, extending forecast ranges and empowering the NWS to deliver advanced weather predictions with extended lead times for high-impact events. The integration of a coupled wave component with higher spatial and temporal resolution and optimized physics parameterizations enhanced forecast skill and predictability, particularly benefiting winter storm predictions of wave heights and peak wave periods. This endeavor encountered challenges addressed by the simultaneous development of new features that enhanced wave model forecast skill and product quality and facilitated by a team collaborating with NOAA’s operational forecasting centers. The GEFSv12 upgrade marks a pivotal shift in NOAA’s global forecasting capabilities, setting a new standard in wave prediction. We also describe the coupled GEFSv12-Wave component impacts on NOAA operational forecasts and ongoing experimental enhancements, which represent a substantial contribution to NOAA’s transition to the fully coupled UFS framework.

3 Jun 2025

Wind Forcing, Source Term and Grid Optimization for Hurricane Wave Modelling in the Gulf of Mexico

Abstract: This study evaluates the performance of WAVEWATCH III model driven by different wind forcing products and behavior of different parameterizations of the model’s source terms controlling energy input and dissipation and quadruplet wave-wave interactions during Hurricane Ida. We also compare the performance of the model configured on uniform unstructured and conventional non-uniform unstructured grids. Key findings show ECMWF-forecast and HRRR out-performed other products in capturing wind speeds relative to buoys, satellite and the revised Atlantic hurricane database observations. However, all products underestimated wind speeds above 20 m/s, with ECMWF and HRRR occasionally performing better for most wind speed values above 35 m/s relative to observations. The corresponding wave simulation results indicated Ida’s wave fields were better captured by model simulations with ECMWF and HRRR wind products, with biases of 2% against buoys in the Gulf of Mexico and 6% and 3% respectively against satellite data. We also highlighted limitations in bulk wave analysis by computing partial Hs and 1D spectra density differences between model and buoy for selected source terms. This reveals consistent overestimation at the lowest frequency bin and underestimation of the three higher frequency bins with a mix of negative and positive energy density difference across different frequencies.

2 Jun 2025

Future Coastal Tundra Loss due to Compounding Environmental Changes in Alaska

Abstract: Anthropogenic climate change is amplified in the Arctic, where less sea ice enables energetic wave climates while higher air and soil temperatures increase tundra erodibility. These changes are likely to exacerbate retreat of coastal tundra yet remain poorly constrained on timescales relevant to storm wave impacts. A stochastic weather generator is used to create 1,000 synthetic hourly time series of waves, water levels, offshore sea ice concentration, and air temperatures used as forcing for an efficient coastal tundra model. The ensemble set of morphological change simulations provides a probabilistic perspective on the range of tundra retreats and the relative effects of each environmental forcing. Ensembles show as the depth of the erodible layer increases, the style of tundra retreat shifts from a consistent recession to intermittent events with large magnitudes and a factor 2 range in outcomes. Model scenarios highlight shallower thaw depths narrows the range of retreats and reduces individual extreme events, but a dynamic feedback between beach slopes, wave runup, and thermally limited erosion volumes ultimately increases the number of storm events associated with retreat. The minimum tundra retreat is governed by background shoreline change and the specifics of the topographic profile dominate underlying changes in the future wave climate statistics and open water season. As the Arctic continues to warm, the change in retreat style will have significant ramifications for coastal resilience.

2 Jun 2025

Miami Harbor Entrance Channel Improvements Study: Ship Simulation Report

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL), Ship/Tow Simulator (STS) was used to perform a navigation study assisting the US Army Corps of Engineers (USACE), Jacksonville District. The study evaluates additional navigation channel modifications from the previous 2019 study to allow larger containerships to call at the Port of Miami. This study was conducted at the CHL real-time STS. Real-time refers to the fact that model time uses a 1:1 ratio to prototype time. In addition, real-world environmental forces were simulated and acted upon the modeled ships during the study. These forces included currents, wind, bathymetry, and bank effects. Simulations for the proposed modifications were conducted at CHL for 1 week in August 2023. Four Biscayne Bay pilots participated in the validation and testing exercises. The design vessels include the MSC Daniela (14,000 twenty-foot equivalent unit [TEU]) container ship and the Maersk Guayaquil (12,000 TEU) container ship. Simulation results are presented in the form of track plots and pilot questionnaires, which were reviewed to develop the conclusions and recommendations.