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Christian E Torgersen

My research interests include landscape ecology, riverine landscapes, watershed processes, ecological scaling, water quality, fish habitat, land use/land cover change, landscape scenario modeling, spatial analysis, remote sensing and GIS.

Education and Certifications

  • Ph.D., Fisheries Science, Oregon State University, Corvallis, OR (2002)

  • M.S., Fisheries Science, Geography Minor, Oregon State University, Corvallis, OR (1996)

  • B.A., Geography/German, double major, University of Oregon, Eugene, OR (1993)

Science and Products

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three scientists preparing to conduct an underwater biological survey

Aquatic & Landscape Ecology Research Team (FRESC)

Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
By
Forest and Rangeland Ecosystem Science Center
link

Aquatic & Landscape Ecology Research Team (FRESC)

Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
Learn More
link
three scientists preparing to conduct an underwater biological survey

Aquatic & Landscape Ecology Research Team (FRESC)

Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
By
Forest and Rangeland Ecosystem Science Center
link

Aquatic & Landscape Ecology Research Team (FRESC)

Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
Learn More
link
USGS science for a changing world

Water Temperature in Rivers and Streams

Increases in summer stream temperature as a result of human impacts and climate change may exceed the thermal tolerances of aquatic biota that are adapted to colder environments and climates. The combined effects of humans and climate change are of global concern across the range of coldwater aquatic organisms.
By
Ecosystems, Species Management Research Program, Forest and Rangeland Ecosystem Science Center
link

Water Temperature in Rivers and Streams

Increases in summer stream temperature as a result of human impacts and climate change may exceed the thermal tolerances of aquatic biota that are adapted to colder environments and climates. The combined effects of humans and climate change are of global concern across the range of coldwater aquatic organisms.
Learn More
link
USGS science for a changing world

Spatial Ecology of Freshwater Ecosystems

Water resources, riparian areas, and aquatic organisms are of critical importance in natural resource management. Yet, they are difficult to map, monitor, and understand in a spatially explicit and extensive manner as can be done more easily in terrestrial environments.
By
Forest and Rangeland Ecosystem Science Center
link

Spatial Ecology of Freshwater Ecosystems

Water resources, riparian areas, and aquatic organisms are of critical importance in natural resource management. Yet, they are difficult to map, monitor, and understand in a spatially explicit and extensive manner as can be done more easily in terrestrial environments.
Learn More
link
WERC Redwood forest field photo

Landscape Patterns and Disturbance

FRESC scientists investigate whole-system processes and relationships across space and time in order to advance understanding of natural, managed, and disturbed ecosystems. This includes research, monitoring, remote sensing, modeling, and synthesis to describe the patterns of change across landscapes and the biological and physical processes that generate them.
By
Land Management Research Program, Forest and Rangeland Ecosystem Science Center
link

Landscape Patterns and Disturbance

FRESC scientists investigate whole-system processes and relationships across space and time in order to advance understanding of natural, managed, and disturbed ecosystems. This includes research, monitoring, remote sensing, modeling, and synthesis to describe the patterns of change across landscapes and the biological and physical processes that generate them.
Learn More
link
USGS science for a changing world logo

Dam removal: synthesis of ecological and physical responses

Dam decommissioning is rapidly emerging as an important river restoration strategy in the U.S., with several major removals recently completed or in progress. But few studies have evaluated the far-reaching consequences of these significant environmental perturbations, especially those resulting from removals of large (>10-15 m tall) structures during the last decade. In particular, interactions b
By
John Wesley Powell Center for Analysis and Synthesis
link

Dam removal: synthesis of ecological and physical responses

Dam decommissioning is rapidly emerging as an important river restoration strategy in the U.S., with several major removals recently completed or in progress. But few studies have evaluated the far-reaching consequences of these significant environmental perturbations, especially those resulting from removals of large (>10-15 m tall) structures during the last decade. In particular, interactions b
Learn More

If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

Spatial and temporal variability of summer water temperature at cool-water areas in the Pend Oreille River, Washington

The water temperature data were collected in summer 2021. Continuously recording temperature loggers were deployed at the confluences of Indian Creek and Duncan Springs in the Pend Oreille River. Loggers were checked every 1-2 weeks throughout the summer.
By
Forest and Rangeland Ecosystem Science Center

Riverscape snorkeling surveys of salmonid distribution and abundance before (2007, 2008) and after (2018, 2019) dam removal on the Elwha River, Washington

We used snorkel surveys in the Elwha River, conducted in consecutive years before (2007, 2008) and after (2018, 2019) dam removal to assess changes in fish distribution and density. In total, we counted 54,616 Chinook Salmon, Bull Trout, Steelhead, and trout (Rainbow Trout and Coastal Cutthroat Trout combined) in 22 common reaches spanning 65 river kilometers. The occupancy of juvenile Chinook Sal
By
Forest and Rangeland Ecosystem Science Center

Airborne thermal infrared remote sensing of summer water temperature in the Middle Fork John Day River (Oregon) in 1994-2003

This data release combines seven airborne thermal infrared (TIR) remote sensing data sets of stream temperature collected along the mainstem of the Middle Fork John Day River (MFJD) in Oregon from 1994 to 2003. Years 1994, 1995, 1996, 1998, and 2002 have single datasets. Year 2003 has two data sets. Most of the TIR data covered the upstream half of the MFJD mainstem between river km 50 and 110, wh
By
Forest and Rangeland Ecosystem Science Center

Water temperature data from the Priest River, Idaho, 2018-2019

Water temperature data were collected in summer 2018 and 2019. Temperature data loggers were deployed in tributary confluences and the mainstem of the lower Priest River between Priest Lake Outlet Dam and the confluence with the Pend Oreille River. Data loggers were checked every 2 to 3 weeks throughout the summer. Data for Lagrangian longitudinal thermal profiles were obtained on August 21, 2018
By
Forest and Rangeland Ecosystem Science Center

Stream Temperature and Water Presence Models of Willow/Whitehorse and Willow/Rock Watersheds, Oregon and Nevada

This data release contains spatial stream network (SSN) objects and R scripts to run SSN models to predict mean monthly stream temperature between May and August and water presence on May 15, June 15, July 15, and August 15 in the Willow/Whitehorse watershed during 2015, 2016, and 2017 and the Willow/Rock watershed during 2016 and 2017. Functions referenced within the script may accessed in the SS
By
Washington Water Science Center

Water temperature data from the Pend Oreille River, Washington and Idaho, 2016-2018

The data were collected summer, 2016, 2017, and 2018. Continuous temperature loggers were deployed along the Pend Oreille River between Albeni Falls Dam and the Box Canyon Dam. Loggers were checked every 1-2 weeks throughout the summer.
By
Forest and Rangeland Ecosystem Science Center
Biologist snorkeling during fish survey
link
three scientists preparing to conduct an underwater biological survey
link

If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

Filter Total Items: 56

Effects of structure and volcanic stratigraphy on groundwater and surface water flow: Hat Creek basin, California, USA

Hydrogeologic systems in the southern Cascade Range in California (USA) develop in volcanic rocks where morphology, stratigraphy, extensional structures, and attendant basin geometry play a central role in groundwater flow paths, groundwater/surface-water interactions, and spring discharge locations. High-volume springs (greater than 3 m3/s) flow from basin-filling (
By
Ecosystems, Water Resources, Land Management Research Program, Volcano Hazards, California Water Science Center, Forest and Rangeland Ecosystem Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Volcano Science Center

Relocated beaver can increase water storage and decrease stream temperature in headwater streams

Many areas are experiencing increasing stream temperatures due to climate change, and some are experiencing reduced summer stream flows and water availability. Because dam building and pond formation by beaver can increase water storage, stream cooling, and riparian ecosystem resilience, beaver have been proposed as a potential climate adaption tool. Despite the large number of studies that have e
By
Ecosystems, Forest and Rangeland Ecosystem Science Center

Keeping an eye on water quality from the sky

You can learn a lot about rivers, lakes, estuaries, and oceans by looking down at them from the sky. Scientists use a technique called remote sensing to measure the amount of light or heat energy reflected and emitted from the Earth. Sensors can be on satellites or mounted on airplanes, helicopters, or drones. Scientists use this information to map the quality of water in the San Francisco Bay-Del
By
Ecosystems, Forest and Rangeland Ecosystem Science Center

Reconnecting the Elwha River: Spatial patterns of fish response to dam removal

The removal of two large dams on the Elwha River was completed in 2014 with a goal of restoring anadromous salmonid populations. Using observations from ongoing field studies, we compiled a timeline of migratory fish passage upstream of each dam. We also used spatially continuous snorkeling surveys in consecutive years before (2007, 2008) and after (2018, 2019) dam removal during summer baseflow t
By
Ecosystems, Fisheries Program (unpublished), Species Management Research Program, Forest and Rangeland Ecosystem Science Center, Western Fisheries Research Center

Riverscape approaches in practice: Perspectives and applications

Landscape perspectives in riverine ecology have been undertaken increasingly in the last 30 years, leading aquatic ecologists to develop a diverse set of approaches for conceptualizing, mapping and understanding ‘riverscapes’. Spatiotemporally explicit perspectives of rivers and their biota nested within the socio-ecological landscape now provide guiding principles and approaches in inland fisheri
By
Ecosystems, Fisheries Program (unpublished), Forest and Rangeland Ecosystem Science Center, Western Fisheries Research Center

A riverscape approach reveals downstream propagation of stream thermal responses to riparian thinning at multiple scales

Hydrological connectivity in river networks influences their response to environmental changes as local effects may extend downstream via flowing water. For example, localized changes in riparian forest conditions can affect stream temperatures, and these effects may propagate downstream. However, studies evaluating stream temperature responses to riparian forest management have not considered cum
By
Ecosystems, Forest and Rangeland Ecosystem Science Center

Integrating regional and local monitoring data and assessment tools to evaluate habitat conditions and inform river restoration

RRestoring degraded rivers requires initial assessment of the fluvial landscape to identify stressors and riverine features that can be enhanced. We associated local-scale river habitat data collected using standardized national monitoring tools with modeled regional water temperature and flow data on mid-sized northwest U.S. rivers (30–60 m wide). We grouped these rivers according to quartiles of
By
Ecosystems, Forest and Rangeland Ecosystem Science Center

Integrating thermal infrared stream temperature imagery and spatial stream network models to understand natural spatial thermal variability in streams

Under a warmer future climate, thermal refuges could facilitate the persistence of species relying on cold-water habitat. Often these refuges are small and easily missed or smoothed out by averaging in models. Thermal infrared (TIR) imagery can provide empirical water surface temperatures that capture these features at a high spatial resolution (
By
Ecosystems, Forest and Rangeland Ecosystem Science Center

Land-cover and climatic controls on water temperature, flow permanence, and fragmentation of Great Basin stream networks

The seasonal and inter-annual variability of flow presence and water temperature within headwater streams of the Great Basin of the western United States limit the occurrence and distribution of coldwater fish and other aquatic species. To evaluate changes in flow presence and water temperature during seasonal dry periods, we developed spatial stream network (SSN) models from remotely sensed land-
By
Ecosystems, Water Resources, Forest and Rangeland Ecosystem Science Center, Washington Water Science Center

Projecting spatiotemporally explicit effects of climate change on stream temperature: A model comparison and implications for coldwater fishes

Conservation planners and resource managers seek information about how the availability and locations of cold-water habitats will change in the future and how these predictions vary among models. We used a physical process-based model to demonstrate the implications of climate change for streamflow and water temperature in two watersheds with distinctive flow regimes: the Snoqualmie watershed (WA)
By
Ecosystems, Forest and Rangeland Ecosystem Science Center

Longitudinal, lateral, vertical, and temporal thermal heterogeneity in a large impounded river: Implications for cold-water refuges

Dam operations can affect mixing of the water column, thereby influencing thermal heterogeneity spatially and temporally. This occurs by restricting or eliminating connectivity in longitudinal, lateral, vertical, and temporal dimensions. We examined thermal heterogeneity across space and time and identified potential cold-water refuges for salmonids in a large impounded river in inland northwester
By
Ecosystems, Forest and Rangeland Ecosystem Science Center

Lidar-based approaches for estimating solar insolation in heavily forested streams

Methods to quantify solar insolation in riparian landscapes are needed due to the importance of stream temperature to aquatic biota. We have tested three lidar predictors using two approaches developed for other applications of estimating solar insolation from airborne lidar using field data collected in a heavily forested narrow stream in western Oregon, USA. We show that a raster methodology bas
By
Ecosystems, Forest and Rangeland Ecosystem Science Center

Non-USGS Publications**

Torgersen, C.E., Close, D.A., 2004, Influence of habitat heterogeneity on the distribution of larval Pacific lamprey (Lampetra tridentata) at two spatial scales: Freshwater Biology, v. 49, no. 5, p. 614-630.
Fausch, K.D., Torgersen, C.E., Baxter, C.V., Li, H.W., 2002, Landscapes to riverscapes- bridging the gap between research and conservation of stream fishes: BioScience, v. 52, no. 6, p. 483-498.
Torgersen, C.E., Faux, R.N., McIntosh, B.A., Poage, N., Norton, D.J., 2001, Airborne thermal remote sensing for water temperature assessment in rivers and streams: Remote Sensing of Environment, v. 76, p. 386-398.
Torgersen, C.E., Price, D.M., Li, H.W., McIntosh, B.A., 1999, Multiscale thermal refugia and stream habitat associations of chinook salmon in northwestern Oregon: Ecological Applications, v. 9, no. 1, p. 301-319, https://doi.org/10.1890/1051-0761(1999)009[0301:MTRASH]2.0.CO;2.
Torgersen, C.E., Poage, N., Flood, M., Norton, D.J., McIntosh, B.A., 1996, Airborne thermal remote sensing of salmonid habitat for restoration planning in Pacific Northwestern watersheds, Baltimore, MD In eds., Proceedings of the Watershed 96 Conference: Alexandria, VA, Water Environment Federation, p. 812-814.
Poage, N., Torgersen, C.E., Norton, D.J., Flood, M., McIntosh, B.A., 1996, Application of thermal infrared (FLIR) and visible videography to the monitoring and restoration of salmonid habitat in the Pacific Northwest In Greer, J.D., ed., Proceedings of the Sixth Forest Service Remote Sensing Applications Conference: Denver, CO, American Society for Photogrammetry and Remote Sensing, p. 376-379.
Torgersen, C.E., Jones, J.A., Moldenke, A.R., LeMaster, M.P., 1995, The spatial heterogeneity of soil invertebrates and edaphic properties in an old growth forest stand in western Oregon In Collins, H.P., Robertson, G.P., Klug, M.J., eds., The Significance and Regulation of Soil Biodiversity: Dordrecht, Netherlands, Kluwer Academic Publishers, p. 225-236.
Torgersen, C.E., Price, D.M., Li, H.W., McIntosh, B.A., 1995, Thermal refugia and chinook salmon habitat in Oregon- Applications of airborne thermal videography In Mausel, P., ed., Proceedings of the 15th Biennial Workshop on Color Photography and Videography: Terre Haute, IN, American Society for Photogrammetry and Remote Sensing, p. 167-171.
Torgersen, C.E., Baxter, C.V., Li, H., McIntosh, B.A., 2006, Landscape influences on longitudinal patterns of river fishes- Spatially continuous analysis of fish-habitat relationships In Hughes, R., Wang, L., Wofford, J.E., eds., Influences of Landscapes on Stream Habitats and Biological Assemblages: Bethesda, MD, American Fisheries Society, p. 473-492

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.

link

Integrating Thermal Infrared Stream Temperature Imagery and Spatial Stream Network Models to Understand Spatial Thermal Variability in Streams

Under a warmer future climate, thermal refuges could facilitate the persistence of species relying on cold-water habitat.

Read Article
link

Modeling Effects of Climate Change on Stream Temperature: Implications for Coldwater Fishes

Resource managers need more accurate information about how cold-water habitats for fish will change in the future. 

Read Article
link

Thermal Heterogeneity in a Large Impounded River: Implications for Cold-Water Refuges

Dam operations can influence spatial and temporal thermal heterogeneity in rivers, yet quantity and distribution of cold-water refuges for salmonids...

Read Article
link

Assessing the Relative Importance of Factors at Multiple Spatial Scales Affecting Terrestrial and Aquatic Wildlife

The ability to understand a given ecological process depends on the scale of observation.

Read Article
link

Using Lidar to Map Solar Insolation in Riparian Areas

Stream temperature is affected by solar insolation, which is the amount of solar radiation at a given location over time. 

Read Article
link

Roadmap for Identifying Coldwater Refuges in Pacific Northwest Rivers

In aquatic ecology, the term "thermal refuge" refers to a cold or warm area in which organisms are protected from unfavorable water temperatures.

Read Article

Science and Products

  • Science
    link
    three scientists preparing to conduct an underwater biological survey

    Aquatic & Landscape Ecology Research Team (FRESC)

    Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
    By
    Forest and Rangeland Ecosystem Science Center
    link

    Aquatic & Landscape Ecology Research Team (FRESC)

    Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
    Learn More
    link
    three scientists preparing to conduct an underwater biological survey

    Aquatic & Landscape Ecology Research Team (FRESC)

    Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
    By
    Forest and Rangeland Ecosystem Science Center
    link

    Aquatic & Landscape Ecology Research Team (FRESC)

    Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
    Learn More
    link
    USGS science for a changing world

    Water Temperature in Rivers and Streams

    Increases in summer stream temperature as a result of human impacts and climate change may exceed the thermal tolerances of aquatic biota that are adapted to colder environments and climates. The combined effects of humans and climate change are of global concern across the range of coldwater aquatic organisms.
    By
    Ecosystems, Species Management Research Program, Forest and Rangeland Ecosystem Science Center
    link

    Water Temperature in Rivers and Streams

    Increases in summer stream temperature as a result of human impacts and climate change may exceed the thermal tolerances of aquatic biota that are adapted to colder environments and climates. The combined effects of humans and climate change are of global concern across the range of coldwater aquatic organisms.
    Learn More
    link
    USGS science for a changing world

    Spatial Ecology of Freshwater Ecosystems

    Water resources, riparian areas, and aquatic organisms are of critical importance in natural resource management. Yet, they are difficult to map, monitor, and understand in a spatially explicit and extensive manner as can be done more easily in terrestrial environments.
    By
    Forest and Rangeland Ecosystem Science Center
    link

    Spatial Ecology of Freshwater Ecosystems

    Water resources, riparian areas, and aquatic organisms are of critical importance in natural resource management. Yet, they are difficult to map, monitor, and understand in a spatially explicit and extensive manner as can be done more easily in terrestrial environments.
    Learn More
    link
    WERC Redwood forest field photo

    Landscape Patterns and Disturbance

    FRESC scientists investigate whole-system processes and relationships across space and time in order to advance understanding of natural, managed, and disturbed ecosystems. This includes research, monitoring, remote sensing, modeling, and synthesis to describe the patterns of change across landscapes and the biological and physical processes that generate them.
    By
    Land Management Research Program, Forest and Rangeland Ecosystem Science Center
    link

    Landscape Patterns and Disturbance

    FRESC scientists investigate whole-system processes and relationships across space and time in order to advance understanding of natural, managed, and disturbed ecosystems. This includes research, monitoring, remote sensing, modeling, and synthesis to describe the patterns of change across landscapes and the biological and physical processes that generate them.
    Learn More
    link
    USGS science for a changing world logo

    Dam removal: synthesis of ecological and physical responses

    Dam decommissioning is rapidly emerging as an important river restoration strategy in the U.S., with several major removals recently completed or in progress. But few studies have evaluated the far-reaching consequences of these significant environmental perturbations, especially those resulting from removals of large (>10-15 m tall) structures during the last decade. In particular, interactions b
    By
    John Wesley Powell Center for Analysis and Synthesis
    link

    Dam removal: synthesis of ecological and physical responses

    Dam decommissioning is rapidly emerging as an important river restoration strategy in the U.S., with several major removals recently completed or in progress. But few studies have evaluated the far-reaching consequences of these significant environmental perturbations, especially those resulting from removals of large (>10-15 m tall) structures during the last decade. In particular, interactions b
    Learn More
  • Data

    If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

    Spatial and temporal variability of summer water temperature at cool-water areas in the Pend Oreille River, Washington

    The water temperature data were collected in summer 2021. Continuously recording temperature loggers were deployed at the confluences of Indian Creek and Duncan Springs in the Pend Oreille River. Loggers were checked every 1-2 weeks throughout the summer.
    By
    Forest and Rangeland Ecosystem Science Center

    Riverscape snorkeling surveys of salmonid distribution and abundance before (2007, 2008) and after (2018, 2019) dam removal on the Elwha River, Washington

    We used snorkel surveys in the Elwha River, conducted in consecutive years before (2007, 2008) and after (2018, 2019) dam removal to assess changes in fish distribution and density. In total, we counted 54,616 Chinook Salmon, Bull Trout, Steelhead, and trout (Rainbow Trout and Coastal Cutthroat Trout combined) in 22 common reaches spanning 65 river kilometers. The occupancy of juvenile Chinook Sal
    By
    Forest and Rangeland Ecosystem Science Center

    Airborne thermal infrared remote sensing of summer water temperature in the Middle Fork John Day River (Oregon) in 1994-2003

    This data release combines seven airborne thermal infrared (TIR) remote sensing data sets of stream temperature collected along the mainstem of the Middle Fork John Day River (MFJD) in Oregon from 1994 to 2003. Years 1994, 1995, 1996, 1998, and 2002 have single datasets. Year 2003 has two data sets. Most of the TIR data covered the upstream half of the MFJD mainstem between river km 50 and 110, wh
    By
    Forest and Rangeland Ecosystem Science Center

    Water temperature data from the Priest River, Idaho, 2018-2019

    Water temperature data were collected in summer 2018 and 2019. Temperature data loggers were deployed in tributary confluences and the mainstem of the lower Priest River between Priest Lake Outlet Dam and the confluence with the Pend Oreille River. Data loggers were checked every 2 to 3 weeks throughout the summer. Data for Lagrangian longitudinal thermal profiles were obtained on August 21, 2018
    By
    Forest and Rangeland Ecosystem Science Center

    Stream Temperature and Water Presence Models of Willow/Whitehorse and Willow/Rock Watersheds, Oregon and Nevada

    This data release contains spatial stream network (SSN) objects and R scripts to run SSN models to predict mean monthly stream temperature between May and August and water presence on May 15, June 15, July 15, and August 15 in the Willow/Whitehorse watershed during 2015, 2016, and 2017 and the Willow/Rock watershed during 2016 and 2017. Functions referenced within the script may accessed in the SS
    By
    Washington Water Science Center

    Water temperature data from the Pend Oreille River, Washington and Idaho, 2016-2018

    The data were collected summer, 2016, 2017, and 2018. Continuous temperature loggers were deployed along the Pend Oreille River between Albeni Falls Dam and the Box Canyon Dam. Loggers were checked every 1-2 weeks throughout the summer.
    By
    Forest and Rangeland Ecosystem Science Center
  • Multimedia
    Biologist snorkeling during fish survey
    link
    three scientists preparing to conduct an underwater biological survey
    link
  • Publications

    If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

    Filter Total Items: 56

    Effects of structure and volcanic stratigraphy on groundwater and surface water flow: Hat Creek basin, California, USA

    Hydrogeologic systems in the southern Cascade Range in California (USA) develop in volcanic rocks where morphology, stratigraphy, extensional structures, and attendant basin geometry play a central role in groundwater flow paths, groundwater/surface-water interactions, and spring discharge locations. High-volume springs (greater than 3 m3/s) flow from basin-filling (
    By
    Ecosystems, Water Resources, Land Management Research Program, Volcano Hazards, California Water Science Center, Forest and Rangeland Ecosystem Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Volcano Science Center

    Relocated beaver can increase water storage and decrease stream temperature in headwater streams

    Many areas are experiencing increasing stream temperatures due to climate change, and some are experiencing reduced summer stream flows and water availability. Because dam building and pond formation by beaver can increase water storage, stream cooling, and riparian ecosystem resilience, beaver have been proposed as a potential climate adaption tool. Despite the large number of studies that have e
    By
    Ecosystems, Forest and Rangeland Ecosystem Science Center

    Keeping an eye on water quality from the sky

    You can learn a lot about rivers, lakes, estuaries, and oceans by looking down at them from the sky. Scientists use a technique called remote sensing to measure the amount of light or heat energy reflected and emitted from the Earth. Sensors can be on satellites or mounted on airplanes, helicopters, or drones. Scientists use this information to map the quality of water in the San Francisco Bay-Del
    By
    Ecosystems, Forest and Rangeland Ecosystem Science Center

    Reconnecting the Elwha River: Spatial patterns of fish response to dam removal

    The removal of two large dams on the Elwha River was completed in 2014 with a goal of restoring anadromous salmonid populations. Using observations from ongoing field studies, we compiled a timeline of migratory fish passage upstream of each dam. We also used spatially continuous snorkeling surveys in consecutive years before (2007, 2008) and after (2018, 2019) dam removal during summer baseflow t
    By
    Ecosystems, Fisheries Program (unpublished), Species Management Research Program, Forest and Rangeland Ecosystem Science Center, Western Fisheries Research Center

    Riverscape approaches in practice: Perspectives and applications

    Landscape perspectives in riverine ecology have been undertaken increasingly in the last 30 years, leading aquatic ecologists to develop a diverse set of approaches for conceptualizing, mapping and understanding ‘riverscapes’. Spatiotemporally explicit perspectives of rivers and their biota nested within the socio-ecological landscape now provide guiding principles and approaches in inland fisheri
    By
    Ecosystems, Fisheries Program (unpublished), Forest and Rangeland Ecosystem Science Center, Western Fisheries Research Center

    A riverscape approach reveals downstream propagation of stream thermal responses to riparian thinning at multiple scales

    Hydrological connectivity in river networks influences their response to environmental changes as local effects may extend downstream via flowing water. For example, localized changes in riparian forest conditions can affect stream temperatures, and these effects may propagate downstream. However, studies evaluating stream temperature responses to riparian forest management have not considered cum
    By
    Ecosystems, Forest and Rangeland Ecosystem Science Center

    Integrating regional and local monitoring data and assessment tools to evaluate habitat conditions and inform river restoration

    RRestoring degraded rivers requires initial assessment of the fluvial landscape to identify stressors and riverine features that can be enhanced. We associated local-scale river habitat data collected using standardized national monitoring tools with modeled regional water temperature and flow data on mid-sized northwest U.S. rivers (30–60 m wide). We grouped these rivers according to quartiles of
    By
    Ecosystems, Forest and Rangeland Ecosystem Science Center

    Integrating thermal infrared stream temperature imagery and spatial stream network models to understand natural spatial thermal variability in streams

    Under a warmer future climate, thermal refuges could facilitate the persistence of species relying on cold-water habitat. Often these refuges are small and easily missed or smoothed out by averaging in models. Thermal infrared (TIR) imagery can provide empirical water surface temperatures that capture these features at a high spatial resolution (
    By
    Ecosystems, Forest and Rangeland Ecosystem Science Center

    Land-cover and climatic controls on water temperature, flow permanence, and fragmentation of Great Basin stream networks

    The seasonal and inter-annual variability of flow presence and water temperature within headwater streams of the Great Basin of the western United States limit the occurrence and distribution of coldwater fish and other aquatic species. To evaluate changes in flow presence and water temperature during seasonal dry periods, we developed spatial stream network (SSN) models from remotely sensed land-
    By
    Ecosystems, Water Resources, Forest and Rangeland Ecosystem Science Center, Washington Water Science Center

    Projecting spatiotemporally explicit effects of climate change on stream temperature: A model comparison and implications for coldwater fishes

    Conservation planners and resource managers seek information about how the availability and locations of cold-water habitats will change in the future and how these predictions vary among models. We used a physical process-based model to demonstrate the implications of climate change for streamflow and water temperature in two watersheds with distinctive flow regimes: the Snoqualmie watershed (WA)
    By
    Ecosystems, Forest and Rangeland Ecosystem Science Center

    Longitudinal, lateral, vertical, and temporal thermal heterogeneity in a large impounded river: Implications for cold-water refuges

    Dam operations can affect mixing of the water column, thereby influencing thermal heterogeneity spatially and temporally. This occurs by restricting or eliminating connectivity in longitudinal, lateral, vertical, and temporal dimensions. We examined thermal heterogeneity across space and time and identified potential cold-water refuges for salmonids in a large impounded river in inland northwester
    By
    Ecosystems, Forest and Rangeland Ecosystem Science Center

    Lidar-based approaches for estimating solar insolation in heavily forested streams

    Methods to quantify solar insolation in riparian landscapes are needed due to the importance of stream temperature to aquatic biota. We have tested three lidar predictors using two approaches developed for other applications of estimating solar insolation from airborne lidar using field data collected in a heavily forested narrow stream in western Oregon, USA. We show that a raster methodology bas
    By
    Ecosystems, Forest and Rangeland Ecosystem Science Center

    Non-USGS Publications**

    Torgersen, C.E., Close, D.A., 2004, Influence of habitat heterogeneity on the distribution of larval Pacific lamprey (Lampetra tridentata) at two spatial scales: Freshwater Biology, v. 49, no. 5, p. 614-630.
    Fausch, K.D., Torgersen, C.E., Baxter, C.V., Li, H.W., 2002, Landscapes to riverscapes- bridging the gap between research and conservation of stream fishes: BioScience, v. 52, no. 6, p. 483-498.
    Torgersen, C.E., Faux, R.N., McIntosh, B.A., Poage, N., Norton, D.J., 2001, Airborne thermal remote sensing for water temperature assessment in rivers and streams: Remote Sensing of Environment, v. 76, p. 386-398.
    Torgersen, C.E., Price, D.M., Li, H.W., McIntosh, B.A., 1999, Multiscale thermal refugia and stream habitat associations of chinook salmon in northwestern Oregon: Ecological Applications, v. 9, no. 1, p. 301-319, https://doi.org/10.1890/1051-0761(1999)009[0301:MTRASH]2.0.CO;2.
    Torgersen, C.E., Poage, N., Flood, M., Norton, D.J., McIntosh, B.A., 1996, Airborne thermal remote sensing of salmonid habitat for restoration planning in Pacific Northwestern watersheds, Baltimore, MD In eds., Proceedings of the Watershed 96 Conference: Alexandria, VA, Water Environment Federation, p. 812-814.
    Poage, N., Torgersen, C.E., Norton, D.J., Flood, M., McIntosh, B.A., 1996, Application of thermal infrared (FLIR) and visible videography to the monitoring and restoration of salmonid habitat in the Pacific Northwest In Greer, J.D., ed., Proceedings of the Sixth Forest Service Remote Sensing Applications Conference: Denver, CO, American Society for Photogrammetry and Remote Sensing, p. 376-379.
    Torgersen, C.E., Jones, J.A., Moldenke, A.R., LeMaster, M.P., 1995, The spatial heterogeneity of soil invertebrates and edaphic properties in an old growth forest stand in western Oregon In Collins, H.P., Robertson, G.P., Klug, M.J., eds., The Significance and Regulation of Soil Biodiversity: Dordrecht, Netherlands, Kluwer Academic Publishers, p. 225-236.
    Torgersen, C.E., Price, D.M., Li, H.W., McIntosh, B.A., 1995, Thermal refugia and chinook salmon habitat in Oregon- Applications of airborne thermal videography In Mausel, P., ed., Proceedings of the 15th Biennial Workshop on Color Photography and Videography: Terre Haute, IN, American Society for Photogrammetry and Remote Sensing, p. 167-171.
    Torgersen, C.E., Baxter, C.V., Li, H., McIntosh, B.A., 2006, Landscape influences on longitudinal patterns of river fishes- Spatially continuous analysis of fish-habitat relationships In Hughes, R., Wang, L., Wofford, J.E., eds., Influences of Landscapes on Stream Habitats and Biological Assemblages: Bethesda, MD, American Fisheries Society, p. 473-492

    **Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

  • News

    To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.

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    Integrating Thermal Infrared Stream Temperature Imagery and Spatial Stream Network Models to Understand Spatial Thermal Variability in Streams

    Under a warmer future climate, thermal refuges could facilitate the persistence of species relying on cold-water habitat.

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    Modeling Effects of Climate Change on Stream Temperature: Implications for Coldwater Fishes

    Resource managers need more accurate information about how cold-water habitats for fish will change in the future. 

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    Thermal Heterogeneity in a Large Impounded River: Implications for Cold-Water Refuges

    Dam operations can influence spatial and temporal thermal heterogeneity in rivers, yet quantity and distribution of cold-water refuges for salmonids...

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    Assessing the Relative Importance of Factors at Multiple Spatial Scales Affecting Terrestrial and Aquatic Wildlife

    The ability to understand a given ecological process depends on the scale of observation.

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    Using Lidar to Map Solar Insolation in Riparian Areas

    Stream temperature is affected by solar insolation, which is the amount of solar radiation at a given location over time. 

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    Roadmap for Identifying Coldwater Refuges in Pacific Northwest Rivers

    In aquatic ecology, the term "thermal refuge" refers to a cold or warm area in which organisms are protected from unfavorable water temperatures.

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