Since joining the U.S. Geological Survey as a Geographer in 2012, Dan's work has focused on the use of Geographic Information Systems (GIS) and remote sensing data to solve watershed-scale questions associated with catastrophic storms, urban development, and resource protection.
Dan also serves as the lead of the Geospatial Analysis and Applications Core Technology Team, a group of geographers, programmers, and statisticians focused on questions related to contaminants and environmental health across spatial scales.
During his university studies, Dan's research focused on using LiDAR to track watershed-scale geomorphic changes associated with the suburbanization of small, historically agricultural watersheds in Montgomery County, MD. During his degrees, Dan worked as a research support specialist at the Baltimore Ecosystem Study Long Term Ecological Research station, assisting in the long-term data collection of water, sediment, and vegetation samples associated with the project.
Education and Certifications
M.S. Geography and Environmental Systems, University of Maryland, Baltimore County, 2013
B.S. Environmental Science, University of Maryland, Baltimore County, 2009
Science and Products
Tracking geomorphic changes after suburban development with a high density of green stormwater infrastructure practices in Montgomery County, Maryland
Addressing stakeholder science needs for integrated drought science in the Colorado River Basin
Ephemeral stream network extraction from lidar-derived elevation and topographic attributes in urban and forested landscapes
Arsenic in private well water and birth outcomes in the United States
Elevation-area-capacity relationships of Lake Powell in 2018 and estimated loss of storage capacity since 1963
Lessons learned from 20 y of monitoring suburban development with distributed stormwater management in Clarksburg, Maryland, USA
A review of algal toxin exposures on reserved federal lands and among trust species in the United States
How will baseflow respond to climate change in the Upper Colorado River Basin?
Machine learning models of arsenic in private wells throughout the conterminous United States as a tool for exposure assessment in human health studies
Modeling estrogenic activity in streams throughout the Potomac and Chesapeake Bay watersheds
Changing climate drives future streamflow declines and challenges in meeting water demand across the southwestern United States
Retrospective analysis of estrogenic endocrine disruption and land-use influences in the Chesapeake Bay watershed
Coproduced Science Linking Environmental and Public-Health Data to Evaluate Drinking Water Arsenic Exposure on Birth Outcomes
Understanding the Effects of Stormwater Management Practices on Water Quality and Flow
Geospatial Analyses and Applications — Salt Lake City, Utah
Geospatial Analyses and Applications — Salt Lake City, Utah
Geospatial Analyses and Applications — Salt Lake City, Utah
Geomorphic metrics across four catchments in Clarksburg, Maryland, 2002-19
Elevation-area-capacity tables for Lake Powell, 2018
Quality assessed and modified Discharge Monitoring Report (DMR) facility and outfall locations, 2007 - 2019
Lidar-derived digital elevation models in Clarksburg, MD representing the years 2002, 2008, 2013, and 2018
Ephemeral channel heads and digital elevation models used to extract stream networks in Clarksburg, MD (ver. 2.0, October 2021)
A snapshot of stakeholder science needs related to drought in the Colorado River Basin
Modified topobathymetric elevation data for Lake Powell
Analytical inorganic chemistry results for samples collected for the Sediment-Bound Contaminant Resiliency and Response Strategy pilot study, northeastern United States, 2015
Matrix inhibition PCR and Microtox 81.9% screening assay analytical results for samples collected for the Sediment-Bound Contaminant Resiliency and Response Strategy pilot study, northeastern United States, 2015
Exposure potential of salt marsh units in Edwin B. Forsythe National Wildlife Refuge to environmental health stressors
Digital Polymerase Chain Reaction (dPCR) and Presence/Absence Quantitative Polymerase Chain Reaction (qPCR) Data From the Sediment-Bound Contaminant Resiliency and Response Strategy Pilot Study, Northeastern United States, 2015
Location, sampling methods and field conditions of resiliency-mode soil and sediment sampling stations sampled, Sediment-Bound Contaminant Resiliency and Response Strategy pilot study, northeastern United States, 2015
Science and Products
- Publications
Filter Total Items: 21
Tracking geomorphic changes after suburban development with a high density of green stormwater infrastructure practices in Montgomery County, Maryland
Stream morphology is affected by changes on the surrounding landscape. Understanding the effects of urbanization on stream morphology is a critical factor for land managers to maintain and improve vulnerable stream corridors in urbanizing landscapes. Stormwater practices are used in urban landscapes to manage runoff volumes and peak flows, potentially mitigating alterations to the flow regime thatAddressing stakeholder science needs for integrated drought science in the Colorado River Basin
Stakeholders need scientific data, analysis, and predictions of how drought the will impact the Colorado River Basin in a format that is continuously updated, intuitive, and easily accessible. The Colorado River Basin Actionable and Strategic Integrated Science and Technology Pilot Project was formed to demonstrate the effectiveness of addressing complex problems through stakeholder involvement anByEcosystems, Water Resources, Arizona Water Science Center, California Water Science Center, Colorado Water Science Center, Fort Collins Science Center, Geology, Geophysics, and Geochemistry Science Center, Nevada Water Science Center, New Mexico Water Science Center, Southwest Biological Science Center, Utah Water Science Center, Washington Water Science Center, Wyoming-Montana Water Science CenterEphemeral stream network extraction from lidar-derived elevation and topographic attributes in urban and forested landscapes
Under-representations of headwater channels in digital stream networks can result in uncertainty in the magnitude of headwater habitat loss, stream burial, and watershed function. Increased availability of high-resolution (Arsenic in private well water and birth outcomes in the United States
BackgroundPrenatal exposure to drinking water with arsenic concentrations >50 μg/L is associated with adverse birth outcomes, with inconclusive evidence for concentrations ≤50 μg/L. In a collaborative effort by public health experts, hydrologists, and geologists, we used published machine learning model estimates to characterize arsenic concentrations in private wells—federally unregulated for driElevation-area-capacity relationships of Lake Powell in 2018 and estimated loss of storage capacity since 1963
Lake Powell is the second largest constructed water reservoir by storage capacity in the United States and represents a critical component in management of water resources in the Colorado River Basin. The reservoir provides hydroelectric power generation at Glen Canyon Dam, banks water storage for the Upper Colorado River Basin, stabilizes water commitments downstream, and buffers the Lower ColoraLessons learned from 20 y of monitoring suburban development with distributed stormwater management in Clarksburg, Maryland, USA
Urban development is a well-known stressor for stream ecosystems, presenting a challenge to managers tasked with mitigating its effects. For the past 20 y, streamflow, water quality, geomorphology, and benthic communities were monitored in 5 watersheds in Montgomery County, Maryland, USA. This study presents a synthesis of multiple studies of monitoring efforts in the study area and new analysis oA review of algal toxin exposures on reserved federal lands and among trust species in the United States
Associated health effects from algal toxin exposure are a growing concern for human and animal health. Algal toxin poisonings may occur from contact with or consumption of water supplies or from ingestion of contaminated animals. The U.S. Federal Government owns or holds in trust about 259 million hectares of land, in addition to the Trust species obligations. We completed the first comprehensiveHow will baseflow respond to climate change in the Upper Colorado River Basin?
Baseflow is critical to sustaining streamflow in the Upper Colorado River Basin. Therefore, effective water resources management requires estimates of baseflow response to climatic changes. This study provides the first estimates of projected baseflow changes from historical (1984 – 2012) to thirty-year periods centered around 2030, 2050, and 2080 under warm/wet, median, and hot/dry climatic condiMachine learning models of arsenic in private wells throughout the conterminous United States as a tool for exposure assessment in human health studies
Arsenic from geologic sources is widespread in groundwater within the United States (U.S.). In several areas, groundwater arsenic concentrations exceed the U.S. Environmental Protection Agency maximum contaminant level of 10 μg per liter (μg/L). However, this standard applies only to public-supply drinking water and not to private-supply, which is not federally regulated and is rarely monitored. AModeling estrogenic activity in streams throughout the Potomac and Chesapeake Bay watersheds
Endocrine-disrupting compounds (EDCs), specifically estrogenic endocrine-disrupting compounds, vary in concentration and composition in surface waters under the influence of different landscape sources and landcover gradients. Estrogenic activity in surface waters may lead to adverse effects in aquatic species at both individual and population levels, often observed through the presence of interseChanging climate drives future streamflow declines and challenges in meeting water demand across the southwestern United States
Society and the environment in the arid southwestern United States depend on reliable water availability, yet current water use outpaces supply. Water demand is projected to grow in the future and climate change is expected to reduce supply. To adapt, water managers need robust estimates of future regional water supply to support management decisions. To address this need, we estimate future streaRetrospective analysis of estrogenic endocrine disruption and land-use influences in the Chesapeake Bay watershed
The Chesapeake Bay is the largest estuary in the United States and its watershed includes river drainages in six states and the District of Columbia. Sportfishing is of major economic interest, however, the rivers within the watershed provide numerous other ecological, recreational, cultural and economic benefits, as well as serving as a drinking water source for millions of people. Consequently, - Science
Coproduced Science Linking Environmental and Public-Health Data to Evaluate Drinking Water Arsenic Exposure on Birth Outcomes
U.S. Geological Survey (USGS) scientists teamed up with public-health epidemiologists to probe for associations between arsenic in drinking water and human-birth outcomes. They reported a modest inverse relation between birth weight and arsenic exposure. Findings indicate that future research efforts using individual-level exposure data such as measured arsenic concentrations in tap water could...Understanding the Effects of Stormwater Management Practices on Water Quality and Flow
Urban development can have detrimental impacts on streams including altering hydrology, increasing nutrient, sediment, and pollutant loadings, and degrading biological integrity. Stormwater Best Management Practices (BMPs) can be used to mitigate the effects of urban development by retaining large volumes of stormwater runoff and treating runoff to remove pollutants. This project focuses on...Geospatial Analyses and Applications — Salt Lake City, Utah
About the ResearchThe Environmental Health Program collaborates with scientists within the Geospatial Analyses and Applications Team to develop and apply geospatial analytical methods to answer broad-scale questions about source-sink and cause-effect relationships between contaminants and vulnerable communities. Multivariate statistics are used to identify connections between landscape gradients...Geospatial Analyses and Applications — Salt Lake City, Utah
About the ResearchThe Environmental Health Program collaborates with scientists within the Geospatial Analyses and Applications Team to develop and apply geospatial analytical methods to answer broad-scale questions about source-sink and cause-effect relationships between contaminants and vulnerable communities. Multivariate statistics are used to identify connections between landscape gradients...Geospatial Analyses and Applications — Salt Lake City, Utah
About the ResearchThe Environmental Health Program collaborates with scientists within the Geospatial Analyses and Applications Team to develop and apply geospatial analytical methods to answer broad-scale questions about source-sink and cause-effect relationships between contaminants and vulnerable communities. Multivariate statistics are used to identify connections between landscape gradients... - Data
Filter Total Items: 13
Geomorphic metrics across four catchments in Clarksburg, Maryland, 2002-19
This dataset contains geomorphic metrics across 32 cross-sections at four catchments within the Clarksburg Special Protection Area in Montgomery County, Maryland. These data were derived from raw cross-sectional data collected by the Montgomery County, Maryland Department of Environmental Protection. Geomorphic metrics include channel area, bed location, channel depth, channel width, and bank moveElevation-area-capacity tables for Lake Powell, 2018
This data release is associated with the following Scientific Investigations Report: Root, J.C. and Jones, D.K., 2022, Elevation-area-capacity relationships of Lake Powell in 2018 and estimated loss of storage capacity since 1963: U.S. Geological Survey Scientific Investigations Report 2022-5017, 21 p., https://doi.org/10.3133/sir20225017. This dataset provides elevation-area-capacity relationshiQuality assessed and modified Discharge Monitoring Report (DMR) facility and outfall locations, 2007 - 2019
Each year the U.S. Environmental Protection Agency (EPA) reports permit, location, and discharge information for facilities across the United States and its territories through the Discharge Monitoring Report (DMR). Because these data are cataloged through a variety of systems, including self-reporting, there are discrepancies that may lead to incorrect spatial interpretation of content in the datLidar-derived digital elevation models in Clarksburg, MD representing the years 2002, 2008, 2013, and 2018
This is a collection of 3 ft resolution digital elevation model derived from light detection and ranging (lidar). Lidar was collected in 2002, 2008, 2013, and 2018. Coverage includes a portion of Clarksburg, Maryland, focused around the Clarksburg Special Protection Area (CSPA). Overall extent varies between each dataset, but all digital elevation models are aligned together with consistent overlaEphemeral channel heads and digital elevation models used to extract stream networks in Clarksburg, MD (ver. 2.0, October 2021)
This dataset describes the location of channel heads survyed in two headwater watersheds in Clarksburg, Montgomery County, Maryland, and the digital elevation models derived from light detection and ranging (lidar) covering the two watersheds. The digital elevation models were used to derive topographic attributes used to delineate drainage networks that were then assessed for accuracy using the fA snapshot of stakeholder science needs related to drought in the Colorado River Basin
Stakeholder science needs were determined by reviewing more than 200 recently published literature items and web pages from Colorado River Basin (CRB) stakeholders. These stakeholder communications were used to characterize over 400 stakeholder science needs by reviewing their priorities, strategies, issues, missions, and concerns related to drought in the CRB. Members of the CRB Integrated SciencByArizona Water Science Center, California Water Science Center, Colorado Water Science Center, Fort Collins Science Center, Geology, Geophysics, and Geochemistry Science Center, Nevada Water Science Center, New Mexico Water Science Center, Southwest Biological Science Center, Utah Water Science Center, Wyoming-Montana Water Science CenterModified topobathymetric elevation data for Lake Powell
This dataset provides a modified version of the previously published Lake Powell topobathymetric digital elevation model (TBDEM; Poppenga and others, 2020). The original TBDEM is comprised of four source datasets: (1) a 2017 1-meter multibeam bathymetric survey; (2) a 2018 topographic light detection and ranging (lidar) derived digital elevation model (DEM); (3) a historical topographic DEM that wAnalytical inorganic chemistry results for samples collected for the Sediment-Bound Contaminant Resiliency and Response Strategy pilot study, northeastern United States, 2015
Coastal communities are uniquely vulnerable to sea-level rise (SLR) and severe storms such as hurricanes. These events enhance the dispersion and concentration of natural and anthropogenic chemicals and pathogenic microorganisms that could adversely affect the health and resilience of coastal communities and ecosystems in coming years. The U.S. Geological Survey has developed the Sediment-Bound CoMatrix inhibition PCR and Microtox 81.9% screening assay analytical results for samples collected for the Sediment-Bound Contaminant Resiliency and Response Strategy pilot study, northeastern United States, 2015
Coastal communities are uniquely vulnerable to sea-level rise (SLR) and severe storms such as hurricanes. These events enhance the dispersion and concentration of natural and anthropogenic chemicals and pathogenic microorganisms that could adversely affect the health and resilience of coastal communities and ecosystems in coming years. The U.S. Geological Survey has developed the Sediment-Bound CoExposure potential of salt marsh units in Edwin B. Forsythe National Wildlife Refuge to environmental health stressors
Natural and anthropogenic contaminants, pathogens, and viruses are found in soils and sediments throughout the United States. Enhanced dispersion and concentration of these environmental health stressors in coastal regions can result from sea level rise and storm-derived disturbances. The combination of existing environmental health stressors and those mobilized by natural or anthropogenic disasteDigital Polymerase Chain Reaction (dPCR) and Presence/Absence Quantitative Polymerase Chain Reaction (qPCR) Data From the Sediment-Bound Contaminant Resiliency and Response Strategy Pilot Study, Northeastern United States, 2015
The purpose of these data sets was to define which samples contained antibiotic resistance genes (screened antibiotic resistance gene targets) and Vibrio species, the number of detectable targets per sample and the quantity of those respective gene targets per gram of soil. These data were determined from samples collected in the NE US in support of the Sediment-bound Contaminant Resiliency and ReLocation, sampling methods and field conditions of resiliency-mode soil and sediment sampling stations sampled, Sediment-Bound Contaminant Resiliency and Response Strategy pilot study, northeastern United States, 2015
Coastal communities are uniquely vulnerable to sea-level rise (SLR) and severe storms such as hurricanes. These events enhance the dispersion and concentration of natural and anthropogenic chemicals and pathogenic microorganisms that could adversely affect the health and resilience of coastal communities and ecosystems in coming years. The U.S. Geological Survey has developed the Sediment-Bound Co