Joel B Sankey, Ph.D.
Joel Sankey is a Research Geologist for the USGS Southwest Biological Science Center (SBSC), and the Grand Canyon Monitoring and Research Center (GCMRC), in Flagstaff, Arizona.
I am also an adjunct professor of the School of Earth and Sustainability (SES) at Northern Arizona University. Previously, I was a Mendenhall Fellow with the USGS Western Geographic Science Center located at the University of Arizona in Tucson. I have a Ph.D. in Engineering and Applied Science from the Geosciences Department at Idaho State University.
Overall, my research focus is on geomorphic and ecosystem processes and function of rivers and upland environments. I characterize and interpret physical and biological land surface change that occurs contemporarily at intra-annual to decadal time scales. I study changes that occur as a function of soil erosion and sediment transport. I also study biophysical processes that change the distribution and composition of vegetation. Many of the land surface changes I study are driven by disturbances caused by people, fires, flooding, and wind. My work is directly relevant to either management actions that are implemented by humans to mitigate these disturbances (e.g., large-scale planting and seeding) or management actions that have either intentionally (e.g., controlled river floods; prescribed fires; removal of invasive vegetation) or unintentionally (e.g., climate change) produced the disturbance and therefore are drivers of change. Increasingly, my work focuses on forecasting how future changes in climate, weather, and hydrology, will affect ecosystems and management outcomes.
Much of my work incorporates remote sensing with digital imagery and topographic data acquired from multispectral and LiDAR sensors on ground-based, airborne (including manned and unmanned aerial vehicles (UAVs)), and satellite platforms. I also use detailed field-investigations for ecological and geomorphic assessment.
At the GCMRC, I lead the remote sensing group. I design our research and monitoring to be responsive to the Glen Canyon Dam Adaptive Management Program (GCDAMP), a Federal Advisory Committee chartered by the US Department of Interior and chaired by the Undersecretary for Water and Science.
Science and Products
UAV lidar and hyperspectral fusion for forest monitoring in the southwestern USA
Aerodynamic roughness length estimation with lidar and imaging spectroscopy in a shrub-dominated dryland
Geomorphic process from topographic form: automating the interpretation of repeat survey data in river valleys
Quantifying geomorphic change at ephemeral stream restoration sites using a coupled-model approach
Scientific monitoring plan in support of the selected alternative of the Glen Canyon Dam Long-Term Experimental and Management Plan
Linking fluvial and aeolian morphodynamics in the Grand Canyon, USA
Four-band image mosaic of the Colorado River corridor downstream of Glen Canyon Dam in Arizona, derived from the May 2013 airborne image acquisition
Channel-planform evolution in four rivers of Olympic National Park, Washington, U.S.A.: The roles of physical drivers and trophic cascades
Remote sensing of tamarisk biomass, insect herbivory, and defoliation: Novel methods in the Grand Canyon Region, Arizona
Conditions and processes affecting sand resources at archeological sites in the Colorado River corridor below Glen Canyon Dam, Arizona
Variability in rainfall at monitoring stations and derivation of a long-term rainfall intensity record in the Grand Canyon Region, Arizona, USA
Predicting watershed post-fire sediment yield with the InVEST sediment retention model: Accuracy and uncertainties
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UAV lidar and hyperspectral fusion for forest monitoring in the southwestern USA
Forest vegetation classification and structure measurements are fundamental steps for planning, monitoring, and evaluating large-scale forest changes including restoration treatments. High spatial and spectral resolution remote sensing data are critically needed to classify vegetation and measure their 3-dimensional (3D) canopy structure at the level of individual species. Here we test high-resoluAuthorsTemuulen T. Sankey, Jonathon Donager, Jason L. McVay, Joel B. SankeyAerodynamic roughness length estimation with lidar and imaging spectroscopy in a shrub-dominated dryland
The aerodynamic roughness length (Z0 m) serves an important role in the flux exchange between the land surface and atmosphere. In this study, airborne lidar (ALS), terrestrial lidar (TLS), and imaging spectroscopy data were integrated to develop and test two approaches to estimate Z0 m over a shrub dominated dryland study area in south-central Idaho, USA. Sensitivity of the two parameterization meAuthorsAihua Li, Wenguang Zhao, Jessica J Mitchell, Nancy F. Glenn, Matthew J. Germino, Joel B. Sankey, Richard M. AllenGeomorphic process from topographic form: automating the interpretation of repeat survey data in river valleys
The ability to quantify the processes driving geomorphic change in river valley margins is vital to geomorphologists seeking to understand the relative role of transport mechanisms (e.g. fluvial, aeolian, and hillslope processes) in landscape dynamics. High-resolution, repeat topographic data are becoming readily available to geomorphologists. By contrasting digital elevation models derived from rAuthorsAlan Kasprak, Joshua J. Caster, Sara G. Bangen, Joel B. SankeyQuantifying geomorphic change at ephemeral stream restoration sites using a coupled-model approach
Rock-detention structures are used as restoration treatments to engineer ephemeral stream channels of southeast Arizona, USA, to reduce streamflow velocity, limit erosion, retain sediment, and promote surface-water infiltration. Structures are intended to aggrade incised stream channels, yet little quantified evidence of efficacy is available. The goal of this 3-year study was to characterize theAuthorsLaura M. Norman, Joel B. Sankey, David Dean, Joshua J. Caster, Stephen B. DeLong, Whitney Henderson-DeLong, Jon D. PelletierScientific monitoring plan in support of the selected alternative of the Glen Canyon Dam Long-Term Experimental and Management Plan
IntroductionThe purpose of this document is to describe a strategy by which monitoring and research data in the natural and social sciences will be collected, analyzed, and provided to the U.S. Department of the Interior (DOI), its bureaus, and to the Glen Canyon Dam Adaptive Management Program (GCDAMP) in support of implementation of the Glen Canyon Dam Long-Term Experimental and Management PlanAuthorsScott P. Vanderkooi, Theodore A. Kennedy, David J. Topping, Paul E. Grams, David L. Ward, Helen C. Fairley, Lucas S. Bair, Joel B. Sankey, Charles B. Yackulic, John C. SchmidtLinking fluvial and aeolian morphodynamics in the Grand Canyon, USA
In river valleys, fluvial and upland landscapes are intrinsically linked through sediment exchange between the active channel, near-channel fluvial deposits, and higher elevation upland deposits. During floods, sediment is transferred from channels to low-elevation nearchannel deposits [Schmidt and Rubin, 1995]. Particularly in dryland river valleys, subsequent aeolian reworking of these flood depAuthorsAlan Kasprak, Sara G. Bangen, Daniel Buscombe, Joshua Caster, Amy E. East, Paul E. Grams, Joel B. SankeyFour-band image mosaic of the Colorado River corridor downstream of Glen Canyon Dam in Arizona, derived from the May 2013 airborne image acquisition
In May 2013, the U.S. Geological Survey’s Grand Canyon Monitoring and Research Center acquired airborne multispectral high-resolution data for the Colorado River in the Grand Canyon, Arizona. The image data, which consist of four color bands (blue, green, red, and near-infrared) with a ground resolution of 20 centimeters, are available to the public as 16-bit geotiff files at http://dx.doi.org/10.AuthorsLaura E. Durning, Joel B. Sankey, Philip A. Davis, Temuulen T. SankeyChannel-planform evolution in four rivers of Olympic National Park, Washington, U.S.A.: The roles of physical drivers and trophic cascades
Identifying the relative contributions of physical and ecological processes to channel evolution remains a substantial challenge in fluvial geomorphology. We use a 74-year aerial photographic record of the Hoh, Queets, Quinault, and Elwha Rivers, Olympic National Park, Washington, U.S.A., to investigate whether physical or trophic-cascade-driven ecological factors—excessive elk impacts after wolveAuthorsAmy E. East, Kurt J. Jenkins, Patricia J. Happe, Jennifer A. Bountry, Timothy J. Beechie, Mark C. Mastin, Joel B. Sankey, Timothy J. RandleRemote sensing of tamarisk biomass, insect herbivory, and defoliation: Novel methods in the Grand Canyon Region, Arizona
Tamarisk is an invasive, riparian shrub species in the southwestern USA. The northern tamarisk beetle (Diorhabda carinulata) has been introduced to several states to control tamarisk. We classified tamarisk distribution in the Glen Canyon National Recreation Area, Arizona using a 0.2 m resolution, airborne multispectral data and estimated tamarisk beetle effects (overall accuracy of 86 percent) leAuthorsTemuulen T. Sankey, Joel B. Sankey, Rene Horne, Ashton BedfordConditions and processes affecting sand resources at archeological sites in the Colorado River corridor below Glen Canyon Dam, Arizona
This study examined links among fluvial, aeolian, and hillslope geomorphic processes that affect archeological sites and surrounding landscapes in the Colorado River corridor downstream from Glen Canyon Dam, Arizona. We assessed the potential for Colorado River sediment to enhance the preservation of river-corridor archeological resources through aeolian sand deposition or mitigation of gully erosAuthorsAmy E. East, Brian D. Collins, Joel B. Sankey, Skye C. Corbett, Helen C. Fairley, Joshua J. CasterVariability in rainfall at monitoring stations and derivation of a long-term rainfall intensity record in the Grand Canyon Region, Arizona, USA
In this study, we examine rainfall datasets of varying temporal length, resolution, and spatial distribution to characterize rainfall depth, intensity, and seasonality for monitoring stations along the Colorado River within Marble and Grand Canyons. We identify maximum separation distances between stations at which rainfall measurements might be most useful for inferring rainfall characteristics aAuthorsJoshua J. Caster, Joel B. SankeyPredicting watershed post-fire sediment yield with the InVEST sediment retention model: Accuracy and uncertainties
Increased sedimentation following wildland fire can negatively impact water supply and water quality. Understanding how changing fire frequency, extent, and location will affect watersheds and the ecosystem services they supply to communities is of great societal importance in the western USA and throughout the world. In this work we assess the utility of the InVEST (Integrated Valuation of EcosysAuthorsJoel B. Sankey, Jason McVay, Jason R. Kreitler, Todd Hawbaker, Nicole Vaillant, Scott Lowe - News