Riparian vegetation has increased dramatically along the Colorado River downstream of Glen Canyon Dam since the closure of the dam in 1963. The spatial patterns and temporal rates of vegetation increase occur due to changes in river hydrology, dam operations, and climate. The increase in vegetation, particularly onto otherwise bare sandbars, has impacted recreational, geomorphological, biological, and cultural resources along the river. Some of the riparian vegetation is non-native, invasive Tamarix that has recently been subject to herbivory and defoliation by the northern tamarisk beetle which has been in the Grand Canyon region since approximately 2009. We use remote sensing of very high resolution multispectral imagery and lidar acquired from fixed-wind airplanes and helicopters to monitor and research the short- and long-term dynamics of riparian vegetation and associated environmental science issues in the region.
Background & Importance
The Grand Canyon Monitoring and Research Center (GCMRC) of the U.S. Geological Survey (USGS)’s Southwest Biological Science Center is the primary science provider for the Glen Canyon Dam Adaptive Management Program (GCDAMP). In support of that mission, GCMRC periodically collects airborne image and lidar data for the Colorado River corridor within Arizona, allowing scientists to study the operational effects of Glen Canyon Dam on the corridor’s natural and cultural resources. The segment of the Colorado River that flows through Glen, Marble and Grand Canyons is characterized by steep terrain and a predominantly narrow, sinuous riparian corridor, making many areas logistically difficult to study. These remote sensing data are used for environmental change detection analysis of the riparian ecosystem. The complete GCMRC remote sensing image archive includes four dates (2002, 2005, 2009 and 2013) of high spatial resolution multispectral image mosaic datasets since 2002, as well as a longer-term record of analog and film-based aerial photography.
General Methods
We use remote sensing change detection of data from the GCMRC archive to monitor and research the short- and long-term dynamics of riparian vegetation and associated environmental science issues in the region. Our methods include multispectral image classification, and lidar and multispectral data fusion to produce landcover data products that are analyzed with map-based change detection and interpreted as a function of other environmental geospatial datasets.
Important Results
Riparian vegetation has increased dramatically along the Colorado River downstream of Glen Canyon Dam since the closure of the dam in 1963. The spatial patterns and temporal rates of vegetation increase occur due to changes in river hydrology, dam operations, and climate. The increase in vegetation, particularly onto otherwise bare sandbars, has impacted recreational, geomorphological, biological, and cultural resources along the river. Some of the riparian vegetation is non-native, invasive Tamarix that has recently been subject to herbivory and defoliation by the northern tamarisk beetle which has been in the Grand Canyon region since approximately 2009.
Below are publications associated with this project.
Four-band image mosaic of the Colorado River corridor downstream of Glen Canyon Dam in Arizona, derived from the May 2013 airborne image acquisition
Remote sensing of tamarisk biomass, insect herbivory, and defoliation: Novel methods in the Grand Canyon Region, Arizona
Riparian vegetation, Colorado River, and climate: five decades of spatiotemporal dynamics in the Grand Canyon with river regulation
Below are partners associated with this project.
- Overview
Riparian vegetation has increased dramatically along the Colorado River downstream of Glen Canyon Dam since the closure of the dam in 1963. The spatial patterns and temporal rates of vegetation increase occur due to changes in river hydrology, dam operations, and climate. The increase in vegetation, particularly onto otherwise bare sandbars, has impacted recreational, geomorphological, biological, and cultural resources along the river. Some of the riparian vegetation is non-native, invasive Tamarix that has recently been subject to herbivory and defoliation by the northern tamarisk beetle which has been in the Grand Canyon region since approximately 2009. We use remote sensing of very high resolution multispectral imagery and lidar acquired from fixed-wind airplanes and helicopters to monitor and research the short- and long-term dynamics of riparian vegetation and associated environmental science issues in the region.
High resolution, multispectral imagery acquired in May of 2013. Image location is the confluence of the Colorado River and Little Colorado River. (Credit: Laura Durning, USGS. Public domain.) Background & Importance
The Grand Canyon Monitoring and Research Center (GCMRC) of the U.S. Geological Survey (USGS)’s Southwest Biological Science Center is the primary science provider for the Glen Canyon Dam Adaptive Management Program (GCDAMP). In support of that mission, GCMRC periodically collects airborne image and lidar data for the Colorado River corridor within Arizona, allowing scientists to study the operational effects of Glen Canyon Dam on the corridor’s natural and cultural resources. The segment of the Colorado River that flows through Glen, Marble and Grand Canyons is characterized by steep terrain and a predominantly narrow, sinuous riparian corridor, making many areas logistically difficult to study. These remote sensing data are used for environmental change detection analysis of the riparian ecosystem. The complete GCMRC remote sensing image archive includes four dates (2002, 2005, 2009 and 2013) of high spatial resolution multispectral image mosaic datasets since 2002, as well as a longer-term record of analog and film-based aerial photography.
General Methods
We use remote sensing change detection of data from the GCMRC archive to monitor and research the short- and long-term dynamics of riparian vegetation and associated environmental science issues in the region. Our methods include multispectral image classification, and lidar and multispectral data fusion to produce landcover data products that are analyzed with map-based change detection and interpreted as a function of other environmental geospatial datasets.
Helicopter acquisition of lidar data in summer of 2013 over the Colorado River (top panel), and the resultant lidar data used for riparian research and monitoring (bottom panel).(Credit: Joel Sankey, USGS. Public domain.) Important Results
Riparian vegetation has increased dramatically along the Colorado River downstream of Glen Canyon Dam since the closure of the dam in 1963. The spatial patterns and temporal rates of vegetation increase occur due to changes in river hydrology, dam operations, and climate. The increase in vegetation, particularly onto otherwise bare sandbars, has impacted recreational, geomorphological, biological, and cultural resources along the river. Some of the riparian vegetation is non-native, invasive Tamarix that has recently been subject to herbivory and defoliation by the northern tamarisk beetle which has been in the Grand Canyon region since approximately 2009.
Panels A and B are high resolution, multispectral imagery at the Kanab Creek confluence with the Colorado River in Grand Canyon showing dense stands of tamarisk vegetation that was green and healthy in May 2009 (panel A), but brown and defoliated in May 2013 due to herbivory by the tamarisk beetle (panel B). Panel C shows a lidar and multispectral image-based classification of tamarisk defoliation (“Tamarisk Decline” in legend) due to the tamarisk beetle along the Colorado River in Glen Canyon. (Credit: Joel Sankey, USGS. Public domain.) - Publications
Below are publications associated with this project.
Four-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. SankeyRemote 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 BedfordRiparian vegetation, Colorado River, and climate: five decades of spatiotemporal dynamics in the Grand Canyon with river regulation
Documentation of the interacting effects of river regulation and climate on riparian vegetation has typically been limited to small segments of rivers or focused on individual plant species. We examine spatiotemporal variability in riparian vegetation for the Colorado River in Grand Canyon relative to river regulation and climate, over the five decades since completion of the upstream Glen CanyonAuthorsJoel B. Sankey, Barbara E. Ralston, Paul E. Grams, John C. Schmidt, Laura E. Cagney - Partners
Below are partners associated with this project.