In the pursuit of serving the public world-class science and data through a culture of excellence, our center seminar series is intended to showcase the best of our region's research into our water resources and to promote inter-disciplinary collaborations between federal, state, local governments, academia, and the general public.
Questions? Contact Zach Clifton at firstname.lastname@example.org.
Measuring Headwater Stream Incision Over Time Using LiDAR-Derived Topographic Metrics
Presented by: Marina Metes
Wednesday, December 20, 2023 at 12 PM ET
Headwater streams can contribute substantial amounts of fine sediment to downstream waterways, especially when severely eroded and incised. Identifying potential upstream sediment sources is crucial for effectively managing water quality, aquatic habitat, and sediment loads in a watershed. Improvements in the spatial-temporal coverage of remotely sensed elevation data derived from lidar allows for a more complete analysis of geomorphic conditions at the watershed scale. We explored a landscape metric derived from a 1 m lidar-derived digital elevation model (DEM), topographic openness (TO), for its ability to detect incised headwater streams. TO is an open-source Python tool and measures the degree of enclosure of each DEM pixel relative to the surrounding landscape. It can be used to detect depressions in the landscape indicative of stream channels, and the degree to which a pixel is enclosed can be used as a proxy for channel incision.
We conducted field surveys in one forested and two recently urbanized headwater watersheds in the Maryland Piedmont to characterize the level of channel incision (none, moderate, or severe) in the main stem of each watershed. Estimates of the severity of channel incision derived from TO were compared against the field surveys. Channel incision was detected with an overall accuracy of 67%, with the best performance having 79-86% accuracy in reaches with either severe or no incision. This method was also applied to repeat lidar collected over the same area to measure the extent of channel incision in 2002 before urban development began, and in 2008 and 2013 during active construction in the urban watersheds. Results showed increasing incision over time in all three watersheds, with similar patterns in the forested and urban watersheds. This new method of remotely measuring channel incision can be used to identify potential sediment sources across a watershed, enhance water and habitat quality predictions, and measure changes over time where multiple years of overlapping lidar are available.
Marina Metes is a physical scientist with the USGS Maryland-Delaware-DC Water Science Center. Her research focuses on using remote sensing techniques to map and measure fluvial geomorphic features, processes, and change. She earned a B.S. in Earth Science from Michigan State University and an M.S. in Geography and Environmental Systems from University of Maryland, Baltimore County.
Predicting Landscape Form and Dynamics and Various Modeling Approaches: A Case Study Implementing Landscape Connectivity with Topographic Filtering Model
Presented by: Se Jong
Wednesday, October 11, 2023 at 12 PM ET
A wide range of modeling approaches exists for simulating landscape processes, each with specific formulation of geomorphic transport laws and predictive capability combining human, physical, and social forces that drive landscape changes. How we build a landscape simulation model depends on a suite of factors, including: what we model, the scale of prediction, why we model, and the current extent of knowledge.
The widespread availability of high-fidelity topography combined with advances in geospatial analysis offer the opportunity to reimagine approaches to the difficult problem of predicting sediment delivery from watersheds. Here we present a model that uses high-resolution topography to filter sediment sources to quantify sediment delivery to the watershed outlet. It is a reduced-complexity, top-down model that defines transfer functions—topographic filters—between spatially distributed sediment sources and spatially integrated sediment delivery. The goal of the model is to forecast changes in watershed suspended sediment delivery in response to spatially distributed changes in sediment source magnitude or delivery, whether a result of watershed drivers or intentional management actions.
Such an application requires the context of a watershed model that accounts for all sediment sources, enforces sediment mass balance throughout the spatial domain, and accommodates sediment storage and delivery over time. The model is developed for a HUC-8 watershed with a flat upland dominated by corn-soybean agriculture and deeply incised valleys near the watershed outlet with large sediment contributions from near-channel sources. Topofilter computes delivery and storage of field-derived sediment according to its spatial and structural connectivity to the stream channel network; subsequently, delivery of both field- and near-channel-derived sediment along with floodplain storage are computed in the stream channel network to the watershed outlet.
The model outputs provide a spatially rich representation of sediment delivery and storage on field and along the stream that is consistent with available independent information on sediment accumulations and fluxes. Rather than a single best-calibrated solution, Topofilter uses the Generalized Likelihood Uncertainty Estimate (GLUE) approach to develop many possible solutions with sediment delivery rates expressed as probability distribution functions across the watershed. The ensemble of simulation outputs provides a useful basis for estimating uncertainty in sediment delivery and the effectiveness of different landscape management allocation across a watershed.
Se Jong develops computer simulation models to organize complex environmental information for understanding sediment sources, transport, and fate across a landscape, and to evaluate landscape management scenarios to inform policy decision analysis. Environmental problems, such as water pollution and land degradation, are essentially social problems; thus, she works in the intersection of social, economic, and environmental dimensions through multi-disciplinary research projects to find innovative solutions to pressing environmental problems across the world.
Using data-driven models to improve early warning forecasts of streamflow and groundwater drought onset, duration, and severity in the Colorado River Basin and across the Conterminous United States
Presented by: John Hammond
Wednesday, September 13, 2023 at 12 PM ET
Drought events will likely be more impactful and difficult to predict incoming years given continued climate change. The U.S. Geological Survey Water Mission Area Drought Program is working to characterize and predict hydrological drought, defined as abnormally low streamflows and groundwater levels. Work at regional and national scales is focused on developing data-driven methods to advance early warning capacity for hydrological drought onset, duration, and severity.
In this presentation we first focus on tree-based and long short-term memory neural network modeling approaches to forecast 0-90 day streamflow drought conditions in the Colorado River Basin using gridded meteorology, modeled snow and soil moisture storage, and watershed properties. Our modeling approaches predict drought for moderate (20%), severe (10%) and extreme (5%) intensity levels using both fixed (one threshold applied to all days and years) and seasonally varying drought thresholds (different drought thresholds for each day of the year).
Quantile regression models are used to estimate streamflow percentiles and uncertainty ranges for 7 and 14 day forecasts, while drought likelihood and duration are modeled using classification approaches for 30 to 90 days. Preliminary regression models for 7 and 14 days had median KGE values of 0.79 and 0.66 for variable thresholds and 0.91 and 0.84 for fixed thresholds. Cohen’s Kappa for classifying moderate intensity drought periods ranged from 0.45 for 30 day fixed threshold forecasts to 0.12 for 90 days, while Kappa values for predicting drought durations ranged from 0.80 for 7 day fixed threshold drought to 0 for 90 day fixed threshold droughts.
Overall, models had weaker predictive ability for regulated basins, increasingly intense droughts, longer lead times, and variable thresholds, and for these reasons modified approaches are being explored to improve model performance. Following regional results, we present outcomes from models predicting streamflow and groundwater drought at sites across the conterminous United States. As we continue to develop prototype forecast tools for assessing and predicting hydrologic drought conditions, we are incorporating stakeholder input to design tools that complement existing drought and water supply prediction tools.
John Hammond is a Research Hydrologist with the USGS MD-DE-DC Water Science Center. He studies hydroclimatic variability and trends, seasonal snow dynamics, empirical streamflow relationships across scales, and remote sensing for better understanding hydrological processes. He obtained a PhD in Watershed Science at Colorado State University in 2018 where he studied hydrologic change across the intermittent-persistent snow transition of the western U.S. in response to snow loss. Before working for the USGS MD-DE-DC Water Science Center in 2015 as a surface water contractor, he obtained an M.S. in Water Resources Science from Oregon State University where he studied trends in streamflow above and below dams in the Columbia River Basin. Out of the office, John is a long-distance biker and hiker, drone photographer of #riversfromabove, small tree enthusiast, and dog parent to Pepper.
Investigating Septic System Impacts in a Rural Sub-watershed: Fluorescent Dissolved Organic Matter and Contaminants of Emerging Concern
Presented by: Anna McClain
Wednesday, August 23, 2023 at 12 PM ET
Septic systems introduce partially treated wastewater, which contains contaminants of emerging concern (CECs), including wastewater-derived fluorescent dissolved organic matter (FDOM), into nearby surface water via groundwater transport. Anna McClain’s group hypothesized that these FDOMs could be employed to quickly and economically identify sections of streams impacted by septic effluent.
They used fluorescence excitation-emission matrix (EEM) spectroscopy and parallel factor analysis (PARAFAC) in conjunction with CEC measurements to characterize septic wastewater and identify potential indicators of septic effluent. The potential indicators were applied to spatially resolved samples from a rural sub-watershed with variable septic density and no municipal wastewater infrastructure.
Anna McClain recently finished her M.S. in Environmental Engineering at the University of Maryland Baltimore County. Her research in the Blaney Lab focused on the impacts of septic systems in Baltimore County.
Impacts on Trihalomethane Formation in Chlorinated Waters
Presented by: Andrew Psoras
Tuesday, August 15, 2023 at 12 PM ET
Natural organic matter and organic contaminants are common constituents of source waters for our drinking water supplies. During water treatment, organic carbon can undergo reactions with free chlorine in disinfection, producing halogenated disinfection byproducts (DBPs), such as Trihalomethanes (THMs) that can vary widely with respect to structure and toxicity.
In this work, the THM yields of two organic micropollutants, parabens and salicylic acids, were investigated. With some unexpected results regarding the bromine content of the resulting THMs, we found evidence of halogen exchange reactions. We explored the extent and efficiency of halogen exchange, and its influence on disinfection byproduct formation.
Andrew Psoras joined the USGS in April 2023 as a Chemist after working for one year as a contractor. He recently completed his M.S. in Environmental Chemistry at Towson University. His thesis research focused on the disinfection chemistry and halogenation rates of phenolic micropollutants in surface waters and wastewaters. Andrew works in the Fate and Bioremediation Team to analyze samples, maintain instruments, and develop or modify analytical methods for specific project objectives.
Geomorphic and Hydrologic Characteristics of Small Urbanized Tributaries to a Fall Zone Stream
Presented by: John Harris
Wednesday, July 12, 2023 at 12:00 PM ET
Many East Coast cities are located along the Fall Zone of major and minor rivers. Many of these rivers contain knickpoints initiated by Pleistocene changes in sea level. The Northwest Branch of the Anacostia River, an urbanized stream in the Washington D.C. Metro Region, has a prominent knickpoint with 20-40 meters of channel incision below the knickpoint along the main channel. As part of the NSF Critical Zone Network Urban Cluster, John is studying tributaries that enter the channel above and below the active knickpoint.
The goal of this project is to determine how mainstem channel incision has influenced tributary morphology, catchment soil thickness, water storage dynamics, and hydrologic response. Tributary spacing, catchment size, and stream gradients differ significantly above and below the knickpoint. Tributaries above the knickpoint are longer, more sinuous, with greater basin area, shallower gradients, and wider floodplains than the downstream tributaries.
Seismic refraction studies indicate that the regolith/bedrock boundary is significantly deeper under the hilltops and thin to absent near the incised channels. He hypothesizes that there is more soil above bedrock available for storage in catchments above the knickpoint, and that the combination of lower gradients and thicker soil intervals results in more effective storage of urban runoff.
John Harris is a Geology M.S. student working with Dr. Karen Prestegaard at the University of Maryland, College Park. Prior to graduate school, he worked in Florida as a staff geologist in the environmental consulting field for six years, focused primarily on site assessment and remediation projects.
Digging into the Data: What Can USGS Streamflow Data Tell Us About Historical Changes Relevant to Different Issues?
Presented by Glenn Hodgkins
Wednesday, June 14, 2023 at 12:00 PM ET
The treasure trove of historical USGS daily value streamflow data is very useful for many purposes, including analyses of historical streamflow trends and variability. This talk will focus on regional, national, and international trends in peak flows, low flows, and the timing of snowmelt-related runoff. Glenn will present a summary of his research over the last 20 years and what insights were gained, both expected and unexpected. There will also be presentation of some work on groundwater trends.
Glenn Hodgkins is a Research Hydrologist with the New England Water Science Center, based in the Maine office. His career has spanned a wide variety of work, including running streamgaging trips for several years and many years of state cooperative projects. He is the lead author or co-author on many journal articles and USGS reports related to statistical hydrology, focusing on trends in various streamflow metrics, groundwater levels, and even lake ice-out dates.
Landsat Based Spatial and Temporal Analysis of Chlorophyll Concentration in the Chesapeake and Delaware Bay Watersheds, 1985-2021
By Kendall Wnuk
Wednesday, May 10, 2023 at 12:00 PM ET
A machine-learning model trained to estimate surface chlorophyll-a concentrations from Landsat data was applied to tidal Chesapeake and Delaware Bay tidal waters from 1985-2021, creating a time-series of chlorophyll-a at a 30-meter scale. These data and associated trends were compared to available nutrient, salinity, discharge, turbidity, and water temperature data to identify spatial and temporal relationships between chlorophyll concentrations and environmental factors.
Kendall Wnuk began his geospatial career with a B.S. in Geology from Washington and Lee University, before continuing on to obtaining a M.S. In Geoscience at Penn State and finally a PhD in Geological Engineering from the Colorado School of Mines. He joined the USGS in 2007 with the International Programs Office, and in 2021 joined the Baltimore office of the MD-DC-DE Water Science Center. His specialties are analyzing remotely sensed optical and radar data.
Urban Stormwaters, Health, and Environmental Justice
By Alisha Chan
Wednesday, April 12, 2023 at 12:00 PM ET
Urban stormwater, human health, and environmental justice are topics that are strongly intertwined. Increasing percentages of impervious surfaces due to urbanization and the increase in frequency of extreme precipitation events due to climate change make urban stormwater runoff an increasingly important problem to address.
This presentation will be a tour de force through the myriad of ways urban stormwater runoff may impact human health:
- Flash flooding, introducing a study we conducted revealing the experience of those impacted by the flash floods in Ellicott City, MD.
- Combined sewer overflows, elaborating on a study we conducted about the incidence of COVID-19 cases in areas with combined sewer overflows.
- The environmental justice paradox that often occurs between green stormwater control measures and marginalized groups through the discussion of a study we conducted about the displacement of racial and ethnic minorities after the installation of green stormwater infrastructure.
Alisha Chan joined the USGS in July 2022, soon after she graduated with her Ph.D. in Environmental Engineering at Yale University. Her dissertation was on the Health and Social Impacts of Stormwater and Flooding. Since starting at the USGS, Alisha has worked on multiple WMA projects about water use, socioeconomics, and social vulnerability. Alisha’s expertise and interests are in environmental justice and environmental health/epidemiology.
Measuring Stream Restoration Success: Urban Stream Restorations Increase Floodplain Soil Carbon and Nutrient Retention Along a Chronosequence
By: Katrina Napora/Florence Bascom Geoscience Center
Wednesday, March 1, 2023 at 12:00 PM ET
Stream restoration is a commonly used management practice to improve water quality via carbon and nutrient retention to meet regulatory or voluntary water quality standards in the Chesapeake Bay watershed. But it can be challenging to measure the success of a stream restoration project. These types of projects have few quantifiable measures of success, no standard metrics, and rarely collect pre-restoration data. However, storage of nutrients, such as phosphorus (P) and carbon (C), in floodplain soils of restored streams can act as an easily quantifiable indicator of restoration success, particularly when the project goals include improved water quality. This study examines phosphorus and carbon concentration in post-restoration floodplain surficial soil samples to see if there is any change in storage of these nutrients over time.
Floodplain surficial soil samples (10 cm depth) were collected from 18 streams in the urbanized Piedmont region of northern Virginia, representing a chronosequence of time (1-10+ years) since restoration, as well as surficial soil samples from unrestored and reference streams. The samples were analyzed for total carbon (TC), total nitrogen (TN) and total phosphorus (TP) retention, whereas carbon dioxide (CO2) mineralization potential and equilibrium phosphorus concentration (EPC0) were measured as metrics of nutrient and carbon loss. These metrics were compared to time since restoration and potential environmental drivers, including soil moisture, pH, particle size, organic matter content, and degree of phosphorus saturation.
Older stream restoration samples indicated increasing nutrient retention for TC, TN, and TP that surpassed both unrestored and reference streams, as well as decreasing carbon mineralization turnover and no significant changes in EPC0. Soil wetness and organic matter, key drivers in nutrient retention, also increased as restoration projects aged increasing nutrient and carbon storage. Overall, stream restoration did improve carbon and nutrient retention in floodplains as compared to unrestored sites and exceeded those of low urbanization ‘reference’ sites.
Incorporating Citizen Science with LSPIV for Reconstructing Flood Hydrographs in Unmonitored Locations by Nick Giro, USGS
Tuesday, July 20, 2021 at 11:00 AM
On May 27, 2018, a devastating flash flood ravaged the community of historic Ellicott City, MD, destroying businesses, vehicles, homes, and livelihoods – it was the second flood of this extent to occur within just 2 years. Unfortunately, no USGS streamgages exist within the rivers in Ellicott City, although indirect discharge estimates were made by the USGS Maryland-Delaware-DC Water Science Center immediately after the event. However, the USGS has been a pioneer in developing and implementing technology using large-scale particle image velocimetry (LSPIV) to indirectly measure discharge, a method that can be suited in situations where traditional discharge measurements are not feasible or where there are no existing streamgages.
This project utilized LSPIV with video footage obtained from social media and security cameras along with a digital elevation model and point cloud datafile made from drone imagery to reconstruct the flood hydrographs of the storm event. The analysis was successful in reconstructing the shape and timing of the hydrographs and further provided a proof of concept for implementing LSPIV with the use of cell phone and security camera footage for further public outreach and potential implementation at existing streamgages.
Nick Giro joined the USGS in 2019 as a hydrologic field assistant while pursuing an undergraduate degree in Environmental Science from UMBC with a focus on hydrology, fluvial geomorphology, and Geographic Information Systems (GIS). He graduated in 2020 and became a hydrologic technician, primarily working on the surface water team collecting and analyzing data regarding streamflow, elevation, and precipitation along with some work in groundwater and sediment sampling.
Quantifying Connectivity and its Effects on Sediment Budgeting for an Agricultural Basin, Chesapeake Bay Watershed, USA by Zach Clifton, USGS
Tuesday, June 29, 2021 at 11:00 AM
Excessive sediment runoff as a result of anthropogenic activities is a major concern for aquatic health to local waterways and estuaries. This study sought to determine the sources, storage and delivery of sediment using a sediment budget approach for the pasture and forested Smith Creek watershed, Virginia USA, a tributary to the Chesapeake Bay.
Erosion from in-stream sources was determined using in-channel measurements and surveys over multiple years and extrapolated to the watershed using lidar data and a watershed prediction model. Erosion from upland sources utilized a novel combination of the RUSLE2 model and an high-spatial resolution index of connectivity to capture transfer of upland eroded sediment to the channel.
This study indicated that streambanks were the major source of sediment in the watershed, corresponding to a previous sediment fingerprinting study in the watershed. In addition, delivered upland sediment was largely determined by the spatial pattern of sediment connectivity among different land-uses.
This study provides a framework for managers to identify areas of excess sediment erosion and delivery in similar tributaries throughout the Chesapeake Bay.
USGS Seminar: Urban stream restoration effectiveness and ecologically realistic expectations by Robert Hilderbrand, Associate Professor at the University of Maryland Center for Environmental Science
Tuesday, February 23, 2021 11:00 a.m.
Urban stream restoration is an important method to mitigate stream degradation in Maryland. Physical attributes such as channel and bank stability can be greatly improved. However, there is little evidence of ecological improvements despite substantial efforts and construction costs. Fewer than 25% of restored streams scored better than their unrestored reaches upstream. The amount of impervious surface cover (ISC) in a watershed may be one of the main factors limiting ecological recovery; as ISC increases, stream health decreases. I used ISC to predict stream ecological condition and compared predictions to existing monitoring data for stream reaches in Montgomery County. Predictions matched closely with monitoring data from reference sites representing the most ecologically intact reaches and lend support to the utility of the method. In contrast, most restored reaches achieved 50% or less of what was predicted given their ISC, and many achieved only 20% of their potential. Restored reaches also achieved less than non-restored, non-reference reaches in the monitoring data. My results suggest that we substantially limit our expectations for ecological improvements arising from urban stream restorations. To aid in planning, I have created prediction maps for all stream reaches in Montgomery County in order to more easily visualize likely ecological outcomes should a stream be restored.
Bob Hilderbrand is an associate professor at the Appalachian Laboratory. While he has very broad interests in both basic and applied science, most of his research comes back to actionable science involving the conservation, management, or restoration of wadeable streams and their biota. His work has substantively contributed to recovery and management plan actions for protecting rare, threatened, and endangered species; the delisting of an endangered species; and additional legal protections to Maryland's coldwater streams. Much of his current research involves the responses of fish, aquatic invertebrates, and overall stream ecological condition to land use and landscape change, including stream restorations. He is also very involved in developing and testing applications from high throughput, next generation DNA sequencing data for stream monitoring and assessment.
Non-Tidal Potomac River Topo/Bathymetric Lidar Coordinated With Other Sensor Platforms & Data Calibration by Roger Barlow and Matthew Cashman, USGS MD-DE-DC Water Science Center
Tuesday, October 20th, 2020 11:00 a.m.
The collection of topo/bathymetric data for a 75 mile segment of the non-tidal Potomac River formed a partnership of interdisciplinary and inter-agency use cases to support USGS science applications, water supply safety, and flood prediction and modeling. The centerpiece of the project was the collection of airborne topo/bathymetric lidar, with significant support from Water, Biology, and Geology Mission Areas for collecting other sensor data using GPS, lidar ground scanning, UAV borne sensors, and boat-based sonar from selected field sites during the airborne lidar collection period. River flow volume, water clarity, and the weather were ideal. Matt and Roger will provide detailed information linking this project to science support, National Geospatial Program lidar capability development, and interagency interest in topo/bathymetric data.
Roger Barlow, National Map Liaison DC, DE, MD, NJ -- Roger has been the Liaison in 14 different states since 1990. He has lived and worked at the Amundsen-Scott South Pole Station in Antarctica and co-authored the first ever image-based geologic map. Roger currently is working with partners on projects using lidar as the primary source of local scale hydrography and chairs the NJ Geospatial Forum Elevation Task Force and the similar Maryland MSGIC. Roger specializes in partnership formation, program coordination, and application of geospatial data to science application.
Matthew Cashman, PhD, Hydrologist/Geomorphologist -- Matthew's interests are in the interdisciplinary interactions between hydrology, geomorphology, and ecology. His current research focuses on modeling hierarchical ecological responses, erosion and habitat mapping using Unmanned Aerial Systems, and developing tools to identify the sources of sediment degrading river habitat, including sediment fingerprinting.
Latest Updates of RSPARROW by Lillian Gorman-Sanisaca, USGS MD-DE-DC Water Science Center
Tuesday, September 15th, 2020 11:00 a.m.
RSPARROW is a system of R scripts and functions for executing and evaluating SPARROW models that generates graphical, map, and tabular output. Users operate the system within RStudio from a single control script that accesses the supporting input files and functions. Only minimal knowledge of R is required to use the system.
SPARROW (SPAtially Referenced Regressions on Watershed attributes) is a spatially explicit, hybrid (statistical and mechanistic) water-quality model developed by the USGS. The model has been used to quantify the sources and transport of contaminants in watersheds of widely varying sizes, from catchment to continental scales. SPARROW includes three major process components that explain spatial variability in stream water quality: (1) contaminant source generation, (2) land-to-water delivery, and (3) stream and reservoir transport and decay. The non-linear and mechanistic structure of the model includes mass balance constraints and non-conservative transport components. This includes factors that control the attenuation and delivery of contaminants to streams via surficial and subsurface pathways and the removal of contaminants in streams and reservoirs, according to first-order decay kinetics. SPARROW is structured as a network of one-dimensional stream segments and their contributing drainage areas.
RSPARROW is designed for novice and experienced modelers, water-quality managers, and R developers. Its features include comprehensive documentation, tutorial models, error checks, interactive maps and diagnostic plots as HTML output files, as well as a built in Rshiny Decision Support System to allow on-the-fly execution of Source Change Management Scenarios. Developer’s tools and an auto-generating workflow execution tree are included to make the code transparent and promote collaboration in the open source environment.
The code and documentation can be found here.
Lillian (Lily) is a Physical Scientist with the USGS. She works on a variety of projects as an expert in the R programming language, Rshiny, and in translation of proprietary programming languages (SAS, Python, etc.) to R. Current research projects include development of RSPARROW and RSPARROW_Bayesian with Richard Alexander and of the Sediment Source Assessment Tool (Sed_SAT) with Allen Gellis.
Base-flow estimation using optimal hydrograph separation with applications to Chesapeake Bay watershed and the continental U.S. by Jeff Raffensperger, USGS MD-DE-DC Water Science Center
Tuesday, August 18th, 2020 11:00 a.m.
Quantitative estimates of base flow are necessary to address questions of the vulnerability and response of aquatic ecosystems to natural and human-induced change in environmental conditions as well as sustainability of water resources. Base flow is often defined as the portion of streamflow that is maintained between precipitation events, fed to stream channels by delayed (usually subsurface) pathways. Base flow is generally not measured directly, but is estimated from observations of streamflow and/or stream-water chemistry...
Artificial Intelligence Applications at the USGS by Hong Jiang, Ph.D.
Thursday, September 5, 2019 10:00 a.m.
The presentation will begin with a brief overview of AI history, current AI research areas, enterprise AI application categories, the benefits of AI and a framework of building up AI capabilities for organizations. Then it will dive into a more detailed discussion of potential AI applications, particularly around process automation, prediction and insight discovery, in the context of the Water Science Center’s mission, current tasks and vision statements. The presentation concludes with a strategy recommendation of choosing AI projects within an organization.
A Flexible Framework for Process-Based Hydraulic and Water Quality Modeling of Best Management Practices by Arash Massoudieh, Ph.D.
Thursday, May 14, 2019 11:00 a.m.
Models that allow for evaluation of the effects of design considerations on the performance of bestmanagement practices (BMPs) and green infrastructure (GI) to control urban and agricultural runoff and associatedcontaminants have received considerable attention in recent years. While popular, the GI models are relativelysimplistic. However, GI model predictions are being relied upon by many municipalities and State/Local agencies tomake decisions about gray vs. green infrastructure improvement planning. Adding complexity to GI modelingframeworks may preclude their use in simpler urban planning situations. Therefore, the goal here was to develop asophisticated, yet flexible tool that could be used by design engineers and researchers to capture and explore theeffect of design factors and properties of the media employed in the performance of GI systems at a relatively smallscale.
U.S. Drought Monitor: A Look Behind the Scenes by Eric Luebehusen, USDA Office of Chief Economist, World Agricultural Outlook Board
Wednesday, December 19th, 2018 11:00 a.m.
This presentation will give a glimpse into several aspects of the weekly U.S. Drought Monitor (USDM). The talk will begin with a history of the USDM, detailing how it went from an experimental to operation product in the span of a couple months in 1999, and how it continues to evolve to meet user needs. He will also discuss the process which culminates with the release of the USDM every Thursday morning, highlighting the role of regional and local expert guidance as well as revealing who works on the map and what the deadlines are. The nuts and bolts of the presentation will involve a brief look at the data used by USDM authors to help guide that week’s drought depiction. Eric will also highlight some of the pitfalls of being an USDM author, which have resulted from the USDM tie ins with USDA Farm Bill as well as some local state drought action plans.
Feel the river rumble: An introduction to fluvial seismology and its application to the 2017 Oroville Dam spillway erosion crisis by Phillip Goodling, Pathways Hydrology Intern USGS MD‐DE‐DC Water Science Center
Wednesday, January 17th, 2018 11:00 a.m.
Flooding rivers create small ground vibrations as bedload is transported and water turbulence applies fluctuating forces to the channel bed. Passive seismic river monitoring has emerged as a new tool in the last decade to infer bedload transport and water turbulence mechanics during floods. In this technique, seismometers are placed safely outside the river banks. Seismic monitoring has the potential advantages of providing continuous reach‐scale information on difficult‐to‐observe processes, though it has the disadvantages of collecting non‐river generated signals. While theoretical and analytical advances have been made, passive seismic methods and their potential geomorphic applications are still being developed.
This presentation introduces the field of fluvial seismology and shows the results of seismic monitoring of the Oroville Dam Crisis. The spillway of the Oroville Dam in California suffered uncontrolled erosion damage in February and March 2017, transforming a simple concrete channel into a complex one. Using a single 3‐component seismometer located 2 km from the dam, we are able to seismically observe the increased turbulence and pinpoint the location of the damage. The new analytical techniques introduced in this study are being applied to ongoing fluvial seismic monitoring in Maryland streams. The presentation will conclude with preliminary results of this monitoring and future research directions
Structure-from-Motion Surveying and Unmanned Aerial Systems: A new resolution of environmental data by Matthew Cashman, USGS MD‐DE‐DC Water Science Center
Wednesday, February 14th, 2018 11:00 a.m.
Structure-from-Motion (SfM) photogrammetry is an emerging imaging technique that is revolutionizing geomorphology and changing the paradigm in restoration and environmental monitoring.
SfM derives three-dimensional structure from a sequence of two-dimensional images and is capable of producing high-resolution landscape models that rival those from light detection and ranging (lidar) at a fraction of the cost. This ability to rapidly capture and quantify spatially-continuous, high-resolution topographic data from both ground-based and Unmanned Aerial System (UAS) platforms makes it uniquely suited to meet a variety of USGS-cooperator needs.
This presentation covers how the Maryland-Delaware-DC Water Science Center has adapted the use of this new survey technique, identified relative strengths and weaknesses, conducted comparisons to traditional methods, and incorporated SfM into our targeting and monitoring workflows for recent cooperator projects.
State and local agencies can benefit from using repeated ground-based or UAS-based SfM surveys to monitor floodplains, identify erosional hotspots, and directly measure streambank erosion for stream restoration projects. The technique can utilize pre-existing lidar to look at historical changes and is also useful to establish a baseline to quantify future coastal change and event-driven beach loss. Additionally, the resolution of data provided by SfM surveying has numerous secondary “value-added” applications such as understanding underlying geomorphic processes, habitat assessment, flow and habitat modeling, and vegetation density and identification.
Microbial Interaction with Carbonaceous Material and the Implications for Environmental Remediation by Trevor Needham, USGS MD‐DE‐DC Water Science Center
Wednesday, February 21th, 2018 11:00 a.m.
Activated carbon and biochar has grown in acceptance for in-situ treatment for polychlorinated biphenyl (PCB) and other persistent organic pollutants (POP) contaminated in sediments by reducing the freely dissolved pore water concentrations that drive aquatic food chain uptake. While decreasing availability to macro-organisms, carbonaceous materials have been demonstrated to enhance microbial and redox availability to sorbed contaminates. In addition to reducing aqueous PCB concentrations, activated carbon has also been evaluated as a possible delivery mechanism for both aerobic and anaerobic PCB degrading bacteria. Recent laboratory and pilot scale studies have been successful in demonstrating bioaugmented activated carbon as a viable treatment option for sediments contaminated with PCBs. The physiochemical properties of different pyrogenic carbon materials (coal AC, coconut hull AC, pinewood BC and graphite powder) have been demonstrated to have different effects of the dechlorination rate of PCB 61 to PCB 23 by the halorespiring bacteria Dehalobium chlorocoercia (DF-1) for in-situ treatment of PCBs by bioamended carbon. These results along with other developments offer a new hybrid approach for in-situ treatment of contaminated sediments and groundwater in the future.
Hurricane Impacts on Chesapeake Bay Over the past 3000 years by Michael Toomey, Research Geologist, US Geological Survey
Wednesday, May 22nd, 2018 11:00 a.m.
The risks posed by infrequent, but devastating, hurricane landfalls remains largely unconstrained due to the short length of robust historic records. This lecture will focus on how pre-historic hurricane events are preserved in coastal sedimentary deposits and what geologic records can tell us about storm activity along the U.S. East Coast, and near Chesapeake Bay, in particular, over the past several thousand years.