My research focuses on the intersection of rivers and the sea. Topics include the movement of sediment within and from coastal watersheds, and how sediment can alter coastal landscapes and habitats. Recently these subjects have been addressed in my work on the Elwha River, Washington, where the largest dam removal project in U.S. history was completed in 2014.
In The News
2017, Los Angeles Times article, “Highway 1 was buried under a massive landslide. Months later, engineers battle Mother Nature to fix it”
2016, The Department of Interior and Lower Elwha Klallam Tribe, International RiverPrize Finalist
2015, New York Times article, “When Dams Come Down, Salmon and Sand Can Prosper”
2014, National Geographic news article, “World’s Largest Dam Removal Unleashes U.S. River After Century of Electric Production”
2013, Book, “Elwha: A River Reborn”
2012, Front-page Seattle Times article, “Dam gone, nature rebuilds Elwha River beach”
2009, Science Daily article, “Sediment Yield From The Tectonically Active Semiarid Western Transverse Ranges Of California”
2006, Environmental Science & Technology news article, “California’s Shifting Sands”
Professional Experience
Research Geologist, GS-15, 2016-present, USGS Pacific Coastal and Marine Science Center, Santa Cruz, California
Research Geologist, GS-14, 2008-2016, USGS Pacific Coastal and Marine Science Center, Santa Cruz, California
Research Geologist, GS-13, 2004-2008, USGS Pacific Coastal and Marine Science Center, Santa Cruz, California
Mendenhall Postdoctoral Fellow, GS-12, 2002-2004, USGS Coastal and Marine Geology Program, Menlo Park, California
Education and Certifications
Ph.D., 2002, University of California, Santa Barbara
M.Sc., 1995, University Wisconsin-Madison
B.Sc., 1993, California Polytechnic State University, San Luis Obispo
Science and Products
Remote Sensing Coastal Change
Coastal Climate Impacts
Using Video Imagery to Study Coastal Change: Santa Cruz Beaches
Climate impacts on Monterey Bay area beaches
Using Video Imagery to Study Coastal Change: Sunset State Beach
DUNEX Aerial Imagery of the Outer Banks
USGS DUNEX Operations on the Outer Banks
California Sand Resource Assessment Project
The Mud Creek Landslide May 20 2017
USGS science supporting the Elwha River Restoration Project
Mapping Land-Use, Hazard Vulnerability and Habitat Suitability Using Deep Neural Networks
Exploring the USGS Science Data Life Cycle in the Cloud
Aerial photogrammetry data and products of the North Carolina coast
Overlapping seabed images and location data acquired using the SQUID-5 system at Looe Key, Florida, in July 2021, with structure-from-motion derived point cloud, digital elevation model and orthomosaic of submerged topography
Overlapping seabed images and location data acquired using the SQUID-5 system at Eastern Dry Rocks coral reef, Florida, in May 2021, with derived point cloud, digital elevation model and orthomosaic of submerged topography
Aerial Imagery of the North Carolina Coast: 2020-02-08 to 2020-02-09
Aerial Imagery of the North Carolina Coast: 2020-05-08 to 2020-05-09
Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, July 2018
Aerial Imagery of the North Carolina Coast: 2019-10-11
Point clouds, bathymetric maps, and orthoimagery generated from overlapping lakebed images acquired with the SQUID-5 system near Dollar Point, Lake Tahoe, CA, March 2021
Aerial Imagery of the North Carolina Coast: 2019-09-08 to 2019-09-13, Post-Hurricane Dorian
Aerial Imagery of the North Carolina Coast: 2019-08-30 and 2019-09-02, Pre-Hurricane Dorian
Overlapping lakebed images and associated GNSS locations acquired near Dollar Point, Lake Tahoe, CA, March 2021
Geophysical and core sample data collected offshore San Francisco, California, during field activity 2019-649-FA from 2019-10-11 to 2019-10-18
Assessment of significant sand resources in Federal and California State Waters of the San Francisco, Oceanside, and Silver Strand littoral cell study areas along the continental shelf of California
Compilation of existing data for sand resource studies in Federal and California State Waters of the San Francisco, Oceanside, and Silver Strand littoral cell study areas along the continental shelf of California—Strategy for field studies and sand resour
Measuring and attributing sedimentary and geomorphic responses to modern climate change: Challenges and opportunities
Fires, floods and other extreme events – How watershed processes under climate change will shape our coastlines
Crowd-sourced SfM: Best practices for high resolution monitoring of coastal cliffs and bluffs
Structure from motion (SfM) photogrammetry is an increasingly common technique for measuring landscape change over time by deriving 3D point clouds and surface models from overlapping photographs. Traditional change detection approaches require photos that are geotagged with a differential GPS (DGPS) location, which requires expensive equipment that can limit the ability of communities and researc
Fire (plus) flood (equals) beach: Coastal response to an exceptional river sediment discharge event
Human-in-the-Loop segmentation of earth surface imagery
Labeling poststorm coastal imagery for machine learning: Measurement of interrater agreement
Processing coastal imagery with Agisoft Metashape Professional Edition, version 1.6—Structure from motion workflow documentation
IntroductionStructure from motion (SFM) has become an integral technique in coastal change assessment; the U.S. Geological Survey (USGS) used Agisoft Metashape Professional Edition photogrammetry software to develop a workflow that processes coastline aerial imagery collected in response to storms since Hurricane Florence in 2018. This report details step-by-step instructions to create three-dimen
A survey of storm-induced seaward-transport features observed during the 2019 and 2020 hurricane seasons
Vegetation of the Elwha River Estuary - Chapter 8
Littoral sediment from rivers: Patterns, rates and processes of river mouth morphodynamics
Cliff Feature Delineation Tool and Baseline Builder, Version 1.0
Dam Removal Information Portal (DRIP)
The Dam Removal Information Portal (DRIP) is an online representation and visualization tool for the USGS Dam Removal Science Database, and provides a map-based visualization of information of dam removals and associated scientific studies.
Science and Products
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Remote Sensing Coastal Change
We use remote-sensing technologies—such as aerial photography, satellite imagery, structure-from-motion (SfM) photogrammetry, and lidar (laser-based surveying)—to measure coastal change along U.S. shorelines.Coastal Climate Impacts
The impacts of climate change and sea-level rise around the Pacific and Arctic Oceans can vary tremendously. Thus far the vast majority of national and international impact assessments and models of coastal climate change have focused on low-relief coastlines that are not near seismically active zones. Furthermore, the degree to which extreme waves and wind will add further stress to coastal...Using Video Imagery to Study Coastal Change: Santa Cruz Beaches
Two video cameras atop the Dream Inn hotel in Santa Cruz, California, overlook the coast in northern Monterey Bay. One camera looks eastward over Santa Cruz Main Beach and boardwalk, while the other looks southward over Cowells Beach.Climate impacts on Monterey Bay area beaches
For beach towns around Monterey Bay, preserving the beaches by mitigating coastal erosion is vital. Surveys conducted now and regularly in the future will help scientists understand the short- and long-term impacts of climate change, El Niño years, and sea-level rise on a populated and vulnerable coastline.Using Video Imagery to Study Coastal Change: Sunset State Beach
Two video cameras overlook the coast at Sunset State Beach in Watsonville, California. Camera 1 looks northwest while Camera 2 looks north. The cameras are part of the Remote Sensing Coastal Change project.DUNEX Aerial Imagery of the Outer Banks
The During Nearshore Event Experiment (DUNEX) project is a large collaborative scientific study focusing on understanding the consequences of coastal storms on the morphology of coastal ecosystems. By flying large sections of the coast and collecting still images using structure from motion (SfM) techniques, we hope to contribute high resolution (20cm) elevation maps for time series comparisons...USGS DUNEX Operations on the Outer Banks
DUring Nearshore Event eXperiment (DUNEX) is a multi-agency, academic, and non-governmental organization (NGO) collaborative community experiment designed to study nearshore coastal processes during storm events. The experiment began in 2019 and is scheduled for completion in the fall of 2021. USGS participation in DUNEX will contribute new measurements and models that will increase our...California Sand Resource Assessment Project
The USGS is working in partnership with the Bureau of Ocean Energy Management (BOEM) and the State of California Ocean Protection Council (OPC) to evaluate sand and gravel resources in Federal and State waters for potential use in future beach nourishment projects. Prior to the leasing and development of outer continental shelf (OCS) sand resources for use in beach restoration or coastal...The Mud Creek Landslide May 20 2017
On May 20, 2017, the steep slopes at Mud Creek on California’s Big Sur coast, about 140 miles south of San Francisco, suffered a catastrophic collapse. USGS scientists from the Pacific Coastal and Marine Science Center and the Geology, Minerals, Energy, and Geophysics Science Center continue to monitor this section of the coastline, in collaboration with the California Department of Transportation...USGS science supporting the Elwha River Restoration Project
The Elwha River Restoration Project has reconnected the water, salmon, and sediment of a pristine river and coast of the Olympic Peninsula of Washington.Mapping Land-Use, Hazard Vulnerability and Habitat Suitability Using Deep Neural Networks
Deep learning is a computer analysis technique inspired by the human brain’s ability to learn. It involves several layers of artificial neural networks to learn and subsequently recognize patterns in data, forming the basis of many state-of-the-art applications from self-driving cars to drug discovery and cancer detection. Deep neural networks are capable of learning many levels of abstraction, an...Exploring the USGS Science Data Life Cycle in the Cloud
Executive Summary Traditionally in the USGS, data is processed and analyzed on local researcher computers, then moved to centralized, remote computers for preservation and publishing (ScienceBase, Pubs Warehouse). This approach requires each researcher to have the necessary hardware and software for processing and analysis, and also to bring all external data required for the workflow over the int - Data
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Aerial photogrammetry data and products of the North Carolina coast
This data release presents structure-from-motion (SfM) products derived from aerial imagery collected along the North Carolina coast in response to storm events and the recovery process. U.S. Geological Survey (USGS) researchers use the aerial imagery and products to assess future coastal vulnerability, nesting habitats for wildlife, and provide data for hurricane impact models. This research is pOverlapping seabed images and location data acquired using the SQUID-5 system at Looe Key, Florida, in July 2021, with structure-from-motion derived point cloud, digital elevation model and orthomosaic of submerged topography
Underwater images were collected using a towed-surface vehicle with multiple downward-looking underwater cameras developed by the U.S. Geological Survey (USGS). The system is named the Structure-from-Motion (SfM) Quantitative Underwater Imaging Device with Five Cameras (SQUID-5). The raw images and associated navigation data were collected at Looe Key, a coral reef located within the Florida KeysOverlapping seabed images and location data acquired using the SQUID-5 system at Eastern Dry Rocks coral reef, Florida, in May 2021, with derived point cloud, digital elevation model and orthomosaic of submerged topography
Underwater images were collected using a towed-surface vehicle with multiple downward-looking underwater cameras developed by the U.S. Geological Survey (USGS). The system is named the Structure-from-Motion (SfM) Quantitative Underwater Imaging Device with Five Cameras (SQUID-5). The raw images and associated navigation data were collected at Eastern Dry Rocks, a coral reef located within the FloAerial Imagery of the North Carolina Coast: 2020-02-08 to 2020-02-09
The U.S. Geological Survey (USGS) Remote Sensing Coastal Change (RSCC) project collects aerial imagery along coastal swaths, in response to storm events, with optimized endlap/sidelap and precise position information to create high-resolution orthomosaics, three-dimensional (3D) point clouds, and digital elevation/surface models (DEMs/DSMs) using Structure-from-Motion (SfM) photogrammetry methods.Aerial Imagery of the North Carolina Coast: 2020-05-08 to 2020-05-09
The U.S. Geological Survey (USGS) Remote Sensing Coastal Change (RSCC) project collects aerial imagery along coastal swaths, in response to storm events, with optimized endlap/sidelap and precise position information to create high-resolution orthomosaics, three-dimensional (3D) point clouds, and digital elevation/surface models (DEMs/DSMs) using Structure-from-Motion (SfM) photogrammetry methods.Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, July 2018
Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the response of a delta system to changesAerial Imagery of the North Carolina Coast: 2019-10-11
The U.S. Geological Survey (USGS) Remote Sensing Coastal Change (RSCC) project collects aerial imagery along coastal swaths, in response to storm events, with optimized endlap/sidelap and precise position information to create high-resolution orthomosaics, three-dimensional (3D) point clouds, and digital elevation/surface models (DEMs/DSMs) using Structure-from-Motion (SfM) photogrammetry methods.Point clouds, bathymetric maps, and orthoimagery generated from overlapping lakebed images acquired with the SQUID-5 system near Dollar Point, Lake Tahoe, CA, March 2021
Underwater images were collected in Lake Tahoe, CA, using a recently developed towed-surface vehicle with multiple downward-looking underwater cameras. The system is named the Structure-from-Motion (SfM) Quantitative Underwater Imaging Device with Five Cameras (SQUID-5). The data were collected March 10th and 11th of 2021 to assess the accuracy, precision, and effectiveness of the new SQUID-5 cameAerial Imagery of the North Carolina Coast: 2019-09-08 to 2019-09-13, Post-Hurricane Dorian
The U.S. Geological Survey (USGS) Remote Sensing Coastal Change (RSCC) project collects aerial imagery along coastal swaths, in response to storm events, with optimized endlap/sidelap and precise position information to create high-resolution orthomosaics, three dimensional (3D) point clouds, and digital elevation/surface models (DEMs/DSMs) using Structure-from-Motion (SfM) photogrammetry methods.Aerial Imagery of the North Carolina Coast: 2019-08-30 and 2019-09-02, Pre-Hurricane Dorian
The U.S. Geological Survey (USGS) Remote Sensing Coastal Change (RSCC) project collects aerial imagery along coastal swaths, in response to storm events, with optimized endlap/sidelap and precise position information to create high-resolution orthomosaics, three dimensional (3D) point clouds, and digital elevation/surface models (DEMs/DSMs) using Structure-from-Motion (SfM) photogrammetry methods.Overlapping lakebed images and associated GNSS locations acquired near Dollar Point, Lake Tahoe, CA, March 2021
Underwater images were collected using a recently developed towed-surface vehicle with multiple downward-looking underwater cameras. The system is named the Structure-from-Motion (SfM) Quantitative Underwater Imaging Device with Five Cameras (SQUID-5). However, there were only 4 cameras operational for this collection due to a cable failure. Images were collected March 10th and 11th of 2021 by towGeophysical and core sample data collected offshore San Francisco, California, during field activity 2019-649-FA from 2019-10-11 to 2019-10-18
The U.S. Geological Survey (USGS) collected geophysical and core sample data aboard the R/V Bold Horizon in 2019 on cruise 2019-649-FA offshore San Francisco, California. The data were collected to assess sand and gravel resources in Federal and State waters for potential use in future beach nourishment projects along stretches of the coast where critical erosion hotspots have been identified. Thi - Multimedia
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Assessment of significant sand resources in Federal and California State Waters of the San Francisco, Oceanside, and Silver Strand littoral cell study areas along the continental shelf of California
Executive SummaryThe Sand Resources Project was established through collaborative agreements between the U.S. Geological Survey (USGS), the Bureau of Ocean Energy Management (BOEM), and the California Ocean Protection Council (OPC) with the purpose of evaluating sand and gravel resources in Federal and California State Waters for potential use in future beach-nourishment projects. Project partnersCompilation of existing data for sand resource studies in Federal and California State Waters of the San Francisco, Oceanside, and Silver Strand littoral cell study areas along the continental shelf of California—Strategy for field studies and sand resour
Executive SummaryThe Sand Resources Project was established through collaborative agreements between the U.S. Geological Survey (USGS), the Bureau of Ocean Energy Management (BOEM), and the California Ocean Protection Council (OPC) with the purpose of evaluating sand and gravel resources in Federal and California State Waters for potential use in future beach-nourishment projects. Project partnersMeasuring and attributing sedimentary and geomorphic responses to modern climate change: Challenges and opportunities
Today, climate change is affecting virtually all terrestrial and nearshore settings. This commentary discusses the challenges of measuring climate-driven physical landscape responses to modern global warming: short and incomplete data records, land use and seismicity masking climatic effects, biases in data availability and resolution, and signal attenuation in sedimentary systems. We identify oppFires, floods and other extreme events – How watershed processes under climate change will shape our coastlines
Ongoing sea-level rise has brought renewed focus on terrestrial sediment supply to the coast because of its strong influence on whether and how long beaches, marshes and other coastal landforms may persist into the future. Here, we summarise findings of sediment discharge from several coastal rivers, revealing that infrequent, large-magnitude events have disproportionate influence on the morphodynCrowd-sourced SfM: Best practices for high resolution monitoring of coastal cliffs and bluffs
Structure from motion (SfM) photogrammetry is an increasingly common technique for measuring landscape change over time by deriving 3D point clouds and surface models from overlapping photographs. Traditional change detection approaches require photos that are geotagged with a differential GPS (DGPS) location, which requires expensive equipment that can limit the ability of communities and researc
Fire (plus) flood (equals) beach: Coastal response to an exceptional river sediment discharge event
Wildfire and post-fire rainfall have resounding effects on hillslope processes and sediment yields of mountainous landscapes. Yet, it remains unclear how fire–flood sequences influence downstream coastal littoral systems. It is timely to examine terrestrial–coastal connections because climate change is increasing the frequency, size, and intensity of wildfires, altering precipitation rates, and acHuman-in-the-Loop segmentation of earth surface imagery
Segmentation, or the classification of pixels (grid cells) in imagery, is ubiquitously applied in the natural sciences. Manual methods are often prohibitively time-consuming, especially those images consisting of small objects and/or significant spatial heterogeneity of colors or textures. Labeling complicated regions of transition that in Earth surface imagery are represented by collections of miLabeling poststorm coastal imagery for machine learning: Measurement of interrater agreement
Classifying images using supervised machine learning (ML) relies on labeled training data—classes or text descriptions, for example, associated with each image. Data-driven models are only as good as the data used for training, and this points to the importance of high-quality labeled data for developing a ML model that has predictive skill. Labeling data is typically a time-consuming, manual procProcessing coastal imagery with Agisoft Metashape Professional Edition, version 1.6—Structure from motion workflow documentation
IntroductionStructure from motion (SFM) has become an integral technique in coastal change assessment; the U.S. Geological Survey (USGS) used Agisoft Metashape Professional Edition photogrammetry software to develop a workflow that processes coastline aerial imagery collected in response to storms since Hurricane Florence in 2018. This report details step-by-step instructions to create three-dimen
ByA survey of storm-induced seaward-transport features observed during the 2019 and 2020 hurricane seasons
Hurricanes are known to play a critical role in reshaping coastlines, but often only impacts on the open ocean coast are considered, ignoring seaward-directed forces and responses. The identification of subaerial evidence for storm-induced seaward transport is a critical step towards understanding its impact on coastal resiliency. The visual features, found in the National Oceanic and AtmosphericVegetation of the Elwha River Estuary - Chapter 8
The Elwha River estuary supports one of the most diverse coastal wetland complexes yet described in the Salish Sea region, in terms of vegetation types and plant species richness. Using a combination of aerial imagery and vegetation plot sampling, we identified 6 primary vegetation types and 121 plant species in a 39.7 ha area. Most of the estuary is dominated by woody vegetation types, with mixedLittoral sediment from rivers: Patterns, rates and processes of river mouth morphodynamics
Rivers provide important sediment inputs to many littoral cells, thereby replenishing sand and gravel of beaches around the world. However, there is limited information about the patterns and processes of littoral-grade sediment transfer from rivers into coastal systems. Here I address these information gaps by examining topographic and bathymetric data of river mouths and constructing sediment bu - Software
Cliff Feature Delineation Tool and Baseline Builder, Version 1.0
The CFDT is an automated computer vision application designed to generate 3D line features representing the seacliff top, midpoint, and toe on high-relief coastal cliffs. The program also delineates 3D points on concavities and convexities across the cliff face (termed subsidiary features), which may represent talus deposits, secondary cliff tops, and secondary cliff toes. The tool package includeDam Removal Information Portal (DRIP)
The Dam Removal Information Portal (DRIP) is an online representation and visualization tool for the USGS Dam Removal Science Database, and provides a map-based visualization of information of dam removals and associated scientific studies.
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