This project characterizes and measures sediment-related effects of landscape disturbances (such as major storms, drought, or wildfire) and river management. We focus primarily on the U.S. west coast, and our work relates to natural hazards and resource management.
Climate models project that in the future the western U.S. will experience more extreme rain events, greater wildfire activity, and more pronounced swings between extreme drought and extreme wet conditions. These changes could result in landscapes shedding more sediment from hillslopes and transporting it along rivers to the coast. At the same time, removal of aging dams is becoming common in the U.S.; dam removal (and some other human activities) releases sediment downstream, changing the river and coastal environments. Our research is guided by the questions: How does the scale of landscape response (such as the amount of sediment generated) correspond to the scale of disturbance (the amount of storm rainfall)? What controls lag times in landscape response signals—how long after a disturbance do its effects appear downstream, and how long do they last? How do superimposed disturbances, such as fire and subsequent storms, or a dam removal followed by extreme rain, combine to drive landscape evolution? How will variations in landscape sediment output affect the amount of sediment reaching the coast, and how might that affect the shape and evolution of beaches?
Currently active tasks:
1. Dam removal. Our team studies river and coastal response to sediment released by large dam removals, in collaboration with other federal, state, tribal, and academic researchers. Research efforts include long-term studies of the Elwha River, Washington (largest dam removal worldwide), the Carmel River (largest dam removal in California), and Klamath estuary (four pending dam removals in California and Oregon).
2. Landscape response to extreme rainfall. Extreme rain can cause major landslides and flooding, greatly increasing the amount of sediment moving along rivers to the coast. We study effects of extreme rain in, for example, the San Lorenzo and Tuolumne Rivers (California), collaborating with the Coastal Change Hazards program, USGS Geology, Minerals, Energy, and Geophysics Science Center, and others.
3. Post-fire sediment mobilization. Hillslopes commonly shed large quantities of sediment in the aftermath of a wildfire, with potential hazards for downstream communities, infrastructure and water supply. The size and duration of these effects vary widely among landscapes, and have not been measured in detail for many regions. We are collaborating with the National Park Service and other partners to investigate post-fire landscape evolution after the 2018 Carr Fire, northern California, a federally declared disaster. Our efforts focus on Whiskeytown National Recreation Area, evaluating sediment movement that affects Whiskeytown Lake and surrounding watersheds.
Below are other science projects associated with this project.
San Francisco Bay Area - Santa Cruz Mountains, CA (BALT-CZU)
Below are data or web applications associated with this project.
River-channel topography, grain size, and turbidity records from the Carmel River, California, before, during, and after removal of San Clemente Dam (ver. 2.0, March 2022)
Polycyclic aromatic hydrocarbons (PAHs) and suspended sediment concentrations in the San Lorenzo River, Santa Cruz, California, USA
Rain measurements in and near the CZU Lightning Complex Fire area, Santa Cruz Mountains, California, 2020 to 2021
Sediment grain-size data from the Klamath estuary, California
Grain-size data for sediment samples collected in Whiskeytown Lake, northern California, in 2018 and 2019
Chirp sub-bottom data collected in 2019 in Whiskeytown Lake, California during USGS field activity 2018-686-FA
River-channel topography and sediment grain size on the Elwha River, Washington, 2006 to 2017
Below are publications associated with this project.
21st-century stagnation in unvegetated sand-sea activity
Fire (plus) flood (equals) beach: Coastal response to an exceptional river sediment discharge event
Watershed sediment yield following the 2018 Carr Fire, Whiskeytown National Recreation Area, northern California
Flooding duration and volume more important than peak discharge in explaining 18 years of gravel–cobble river change
Landscape evolution in eastern Chuckwalla Valley, Riverside County, California
River floodplain abandonment and channel deepening coincide with the onset of clear-cut logging in a coastal California redwood forest
Geomorphic and sedimentary effects of modern climate change: Current and anticipated future conditions in the western United States
World’s largest dam removal reverses coastal erosion
Morphodynamic evolution following sediment release from the world’s largest dam removal
Sediment pulses can cause widespread, complex changes to rivers and coastal regions. Quantifying landscape response to sediment-supply changes is a long-standing problem in geomorphology, but the unanticipated nature of most sediment pulses rarely allows for detailed measurement of associated landscape processes and evolution. The intentional removal of two large dams on the Elwha River (Washingto
Conceptualizing ecological responses to dam removal: If you remove it, what's to come?
Geomorphic evolution of a gravel‐bed river under sediment‐starved vs. sediment‐rich conditions: River response to the world's largest dam removal
Understanding river response to sediment pulses is a fundamental problem in geomorphic process studies, with myriad implications for river management. However, because large sediment pulses are rare and usually unanticipated, they are seldom studied at field scale. We examine fluvial response to a massive (~20 Mt) sediment pulse released by the largest dam removal globally, on the Elwha River, Was
A regime shift in sediment export from a coastal watershed during a record wet winter, California: Implications for landscape response to hydroclimatic extremes
Below are news stories associated with this project.
- Overview
This project characterizes and measures sediment-related effects of landscape disturbances (such as major storms, drought, or wildfire) and river management. We focus primarily on the U.S. west coast, and our work relates to natural hazards and resource management.
USGS scientists examining landslides in the Tuolumne watershed, California, caused by an extreme rain event in 2018. Photo credit: Ian Buckley Climate models project that in the future the western U.S. will experience more extreme rain events, greater wildfire activity, and more pronounced swings between extreme drought and extreme wet conditions. These changes could result in landscapes shedding more sediment from hillslopes and transporting it along rivers to the coast. At the same time, removal of aging dams is becoming common in the U.S.; dam removal (and some other human activities) releases sediment downstream, changing the river and coastal environments. Our research is guided by the questions: How does the scale of landscape response (such as the amount of sediment generated) correspond to the scale of disturbance (the amount of storm rainfall)? What controls lag times in landscape response signals—how long after a disturbance do its effects appear downstream, and how long do they last? How do superimposed disturbances, such as fire and subsequent storms, or a dam removal followed by extreme rain, combine to drive landscape evolution? How will variations in landscape sediment output affect the amount of sediment reaching the coast, and how might that affect the shape and evolution of beaches?
Currently active tasks:
1. Dam removal. Our team studies river and coastal response to sediment released by large dam removals, in collaboration with other federal, state, tribal, and academic researchers. Research efforts include long-term studies of the Elwha River, Washington (largest dam removal worldwide), the Carmel River (largest dam removal in California), and Klamath estuary (four pending dam removals in California and Oregon).
2. Landscape response to extreme rainfall. Extreme rain can cause major landslides and flooding, greatly increasing the amount of sediment moving along rivers to the coast. We study effects of extreme rain in, for example, the San Lorenzo and Tuolumne Rivers (California), collaborating with the Coastal Change Hazards program, USGS Geology, Minerals, Energy, and Geophysics Science Center, and others.
3. Post-fire sediment mobilization. Hillslopes commonly shed large quantities of sediment in the aftermath of a wildfire, with potential hazards for downstream communities, infrastructure and water supply. The size and duration of these effects vary widely among landscapes, and have not been measured in detail for many regions. We are collaborating with the National Park Service and other partners to investigate post-fire landscape evolution after the 2018 Carr Fire, northern California, a federally declared disaster. Our efforts focus on Whiskeytown National Recreation Area, evaluating sediment movement that affects Whiskeytown Lake and surrounding watersheds.
Research geologist Amy East confers with physical scientist Josh Logan, preparing to conduct a lidar survey near the mouth of the Elwha River in Washington. Evolution of the shoreline around the Elwha River mouth, Washington, before, during and after dam removal, 2011–2017. Two large dams were removed from the Elwha River between 2011 and 2014 in the largest dam removal worldwide thus far, releasing more than 20 million tons of sediment downstream. These images show the effects of new sediment depositing around the river mouth and being reworked by waves and currents. The Elwha River and other recent dam-removal sites are generating new understanding of ways in which river and coastal systems respond to human activity. A two-day rainstorm from January 26-28, 2021 caused numerous mudslides, debris flows, and other issues along California's coastal Highway 1 through Big Sur. This section is just north of Kirk Creek, at a drainage where mud was washed across the roadway. Plumes of the muddy runoff are clearly visible in the ocean. In the aftermath of the 2018 Carr Fire, northern California, sediment has eroded from burned hillslopes and accumulated in some areas of Whiskeytown Lake. A recent sediment deposit is shown here in the Whiskey Creek section of the lake. USGS scientists study landscape evolution after fires and storm rainfall to determine how intensively these disturbances impact affected areas and for how long. - Science
Below are other science projects associated with this project.
San Francisco Bay Area - Santa Cruz Mountains, CA (BALT-CZU)
Landslides in the San Francisco Bay Area of California impact people, infrastructure, and the environmnent, and are commonly induced by intense or prolonged rainfall associated with strong winter storms. - Data
Below are data or web applications associated with this project.
River-channel topography, grain size, and turbidity records from the Carmel River, California, before, during, and after removal of San Clemente Dam (ver. 2.0, March 2022)
The San Clemente Dam, built in the 1920s on the Carmel River in Monterey County, California, was removed during 2014 and 2015. The dam-removal project was the largest in California to date, and one of the largest in the U.S. This USGS data release presents data collected before, during, and after the removal of the dam. The data were collected to study how the river channel's topographic profilesPolycyclic aromatic hydrocarbons (PAHs) and suspended sediment concentrations in the San Lorenzo River, Santa Cruz, California, USA
Water from the San Lorenzo River in Santa Cruz, California, was sampled to analyze for polycyclic aromatic hydrocarbons (PAHs) and suspended sediment concentrations (SSC) during the rainy seasons from 2008 to 2019 following drought conditions. The samples were collected using a US D-95 depth-integrated water sampler deployed from a bridge-box platform beneath a pedestrian bridge For each suspendeRain measurements in and near the CZU Lightning Complex Fire area, Santa Cruz Mountains, California, 2020 to 2021
The CZU Lightning Complex Fire (hereafter, "CZU Fire") ignited in the Santa Cruz Mountains, California, on August 16, 2020. By the time of full containment on September 22, 2020, the fire had burned 350 km2 (86,510 acres) in Santa Cruz and San Mateo Counties. The U.S. Geological Survey (USGS) installed four rain gages in and near the CZU Fire burn area to measure rainfall during the post-fire wetSediment grain-size data from the Klamath estuary, California
This data release includes grain-size measurements of sediment samples collected from the substrate surface and uppermost 10 cm of sediment deposits in the Klamath estuary, northern California. Samples were collected using a BMH-60 bed-material sampler deployed from a boat, or by hand trowel from subaerial or shallow-water (less than 0.5 m water depth) regions along the estuary margins and side chGrain-size data for sediment samples collected in Whiskeytown Lake, northern California, in 2018 and 2019
The Carr Fire ignited in northern California in July 2018, and ultimately burned almost 300,000 acres (approximately half on federal lands), resulting in a federal major-disaster declaration (DR-4382). Approximately 93% of the area within Whiskeytown National Recreation Area was burned extensively during the Carr Fire, including all of the landscape surrounding and draining into Whiskeytown Lake.Chirp sub-bottom data collected in 2019 in Whiskeytown Lake, California during USGS field activity 2018-686-FA
High-resolution chirp sub-bottom data were collected by the U.S. Geological Survey, Pacific Coastal and Marine Science Center in May of 2019 in Whiskeytown Lake, California using an Edgetech SB-512i sub-bottom profiler. These data were collected to measure possible debris flows into the lake during the 2018-2019 rainy season following the July-August 2018 Carr fire that burned vegetation around thRiver-channel topography and sediment grain size on the Elwha River, Washington, 2006 to 2017
The Elwha River, Washington, USA, was the site of the largest dam-removal project to date, in which two dams were removed between 2011 and 2014. Dam removal was made in stages over about a one-year period for the Elwha Dam (32 m high) and a three-year period for the Glines Canyon Dam (64 m high). This data release presents topographic and sediment grain size data collected by the U.S. Geological S - Publications
Below are publications associated with this project.
Filter Total Items: 1821st-century stagnation in unvegetated sand-sea activity
Sand seas are vast expanses of Earth’s surface containing large areas of aeolian dunes—topographic patterns manifest from above-threshold winds and a supply of loose sand. Predictions of the role of future climate change for sand-sea activity are sparse and contradictory. Here we examine the impact of climate on all of Earth’s presently-unvegetated sand seas, using ensemble runs of an Earth SystemFire (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 acWatershed sediment yield following the 2018 Carr Fire, Whiskeytown National Recreation Area, northern California
Wildfire risk has increased in recent decades over many regions, due to warming climate and other factors. Increased sediment export from recently burned landscapes can jeopardize downstream infrastructure and water resources, but physical landscape response to fire has not been quantified for some at-risk areas, including much of northern California, USA. We measured sediment yield from three watFlooding duration and volume more important than peak discharge in explaining 18 years of gravel–cobble river change
Floods play a critical role in geomorphic change, but whether peak magnitude, duration, volume, or frequency determines the resulting magnitude of erosion and deposition is a question often proposed in geomorphic effectiveness studies. This study investigated that question using digital elevation model differencing to compare and contrast three hydrologically distinct epochs of topographic changeLandscape evolution in eastern Chuckwalla Valley, Riverside County, California
This study investigates sedimentary and geomorphic processes in eastern Chuckwalla Valley, Riverside County, California, a region of arid, basin-and-range terrain where extensive solar-energy development is planned. The objectives of this study were to (1) measure local weather parameters and use them to model aeolian sediment-transport potential; (2) identify surface sedimentary characteristics iRiver floodplain abandonment and channel deepening coincide with the onset of clear-cut logging in a coastal California redwood forest
Changes in both land use and climate can alter the balance of transport capacity and sediment supply in rivers. Hence, the primary driver of recent incision or aggradation in alluvial channels is often unclear. The San Lorenzo River on the central coast of California is one location where both climate and land use—specifically, clear-cut forestry of coastal redwoods—could explain recent vertical iGeomorphic and sedimentary effects of modern climate change: Current and anticipated future conditions in the western United States
Hydroclimatic changes associated with global warming over the past 50 years have been documented widely, but physical landscape responses are poorly understood thus far. Detecting sedimentary and geomorphic signals of modern climate change presents challenges owing to short record lengths, difficulty resolving signals in stochastic natural systems, influences of land use and tectonic activity, lonWorld’s largest dam removal reverses coastal erosion
Coastal erosion outpaces land generation along many of the world’s deltas and a significant percentage of shorelines, and human-caused alterations to coastal sediment budgets can be important drivers of this erosion. For sediment-starved and erosion-prone coasts, large-scale enhancement of sediment supply may be an important, but poorly understood, management option. Here we provide new topographiMorphodynamic evolution following sediment release from the world’s largest dam removal
Sediment pulses can cause widespread, complex changes to rivers and coastal regions. Quantifying landscape response to sediment-supply changes is a long-standing problem in geomorphology, but the unanticipated nature of most sediment pulses rarely allows for detailed measurement of associated landscape processes and evolution. The intentional removal of two large dams on the Elwha River (Washingto
ByEcosystems, Natural Hazards, Water Resources, Coastal and Marine Hazards and Resources Program, Fisheries Program (unpublished), Arizona Water Science Center, Pacific Coastal and Marine Science Center, Washington Water Science Center, Western Fisheries Research Center, Sediment Lab Suite and Carbon Analysis LaboratoryConceptualizing ecological responses to dam removal: If you remove it, what's to come?
One of the desired outcomes of dam decommissioning and removal is the recovery of aquatic and riparian ecosystems. To investigate this common objective, we synthesized information from empirical studies and ecological theory into conceptual models that depict key physical and biological links driving ecological responses to removing dams. We define models for three distinct spatial domains: upstreByEcosystems, Coastal and Marine Hazards and Resources Program, Species Management Research Program, Arizona Water Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, Geology, Minerals, Energy, and Geophysics Science Center, John Wesley Powell Center for Analysis and Synthesis, Oregon Water Science Center, Pacific Coastal and Marine Science Center, Western Fisheries Research CenterGeomorphic evolution of a gravel‐bed river under sediment‐starved vs. sediment‐rich conditions: River response to the world's largest dam removal
Understanding river response to sediment pulses is a fundamental problem in geomorphic process studies, with myriad implications for river management. However, because large sediment pulses are rare and usually unanticipated, they are seldom studied at field scale. We examine fluvial response to a massive (~20 Mt) sediment pulse released by the largest dam removal globally, on the Elwha River, Was
A regime shift in sediment export from a coastal watershed during a record wet winter, California: Implications for landscape response to hydroclimatic extremes
Small, steep watersheds are prolific sediment sources from which sediment flux is highly sensitive to climatic changes. Storm intensity and frequency are widely expected to increase during the 21st century, and so assessing the response of small, steep watersheds to extreme rainfall is essential to understanding landscape response to climate change. During record winter rainfall in 2016–2017, the - News
Below are news stories associated with this project.