These data are remote sensing image-based classification maps of unvegetated river-derived sand along the Colorado River. One map is based on imagery acquired in May 2013 and is a classification of sand located above the wetted river channel in the imagery which was acquired at the approximate contemporary low-flow river discharge of 8,000 cubic feet per second (227 cubic meters per second) and extends from Glen Canyon Dam at Lake Powell to Separation Canyon at Lake Mead, a total distance of approximately 255 river miles (410 river kilometer). Three other maps are based on imagery acquired in May 2002, 2009, and 2013, respectively, and are classifications of sand located above the wetted river channel (at river discharge of approximately 8,000 cubic feet per second, or 227 cubic meters per second) and below the approximate maximum contemporary flood stage of the river at a discharge of 45,000 cubic feet per second (1,274 cubic meters per second). Those three maps extend from Lees Ferry (approximately 15 miles downstream of Glen Canyon Dam) to Diamond Creek, a total distance of approximately 226 river miles (364 river kilometers). These three maps only have sand classified within large sand deposition zones (SDZs) in the river corridor. Sand transported by the Colorado River through Grand Canyon is stored on the river bed and in recirculation zones, or eddies, that typically house separation or reattachment sandbars in the lee of debris fans (Schmidt, 1990; Hazel et al., 2006). Alternatively, sand can also be found lining pools and channel margins upstream of debris fans (Schmidt, 1990). The SDZs were identified by delineating individual large eddies and adjacent debris fans, pools and channel margins which contain a majority of the areas of exposed unvegetated river-derived sand that can be classified by multispectral image analysis. The more comprehensive 2013 sand map extends outside of the SDZs and encompasses all river-derived sand within the entire width and length of the river corridor above the low-flow river stage. Each classification map was derived from a combination of unsupervised and supervised image classification methods followed by exhaustive image interpretation and map editing to identify river-derived sand that was not vegetated and not obviously colonized by biologic soil crust. The sand classifications have the same 0.2-meter ground resolution as the imagery. No formal accuracy assessment has been completed at this time for these data.

These data were compiled to show where significant river-sourced aeolian sediment deposits are present along the Colorado River downstream of Glen Canyon Dam in the Grand Canyon from Lee’s Ferry to the Diamond Creek confluence located 225 miles downstream. These deposits represent 118 active aeolian dunefields and were created by the Grand Canyon Monitoring & Research Center using field data and 20-cm pixel resolution, four spectral band imagery collected in 2013 (Durning and others, 2016) and validated using field observations and oblique photography. River-sourced sediment associated with these dunfields were excluded that were within the modeled inundation extent during a 1,274 m3/s (45,000 ft3/s) river flow scenario, representing the contemporary maximum controlled river flood release from Glen Canyon Dam. Dunefields are termed source-bordering aeolian dunefields and are comprised of wind deposited, river-sourced sand.

These data area classified maps of water in the Colorado River at a discharge of approximately 227 meters squared/second in Grand Canyon from Glen Canyon Dam to Pearce Ferry in Arizona. The data are derived from interpretation of multispectral high resolution airborne imagery that was acquired in May 2013. The water classification data have the same 0.2-meter ground resolution as the imagery. These data have not undergone a statistical accuracy assessment, but they are based on methods that included image interpretation to exhaustively identify water which have been shown to produce very high classification accuracies and excellent correlation between maps of total vegetation produced by independent analysts and ground truth. When developing these data from the native raster format we also considered the differences in water origin, and differentiated between water in the Colorado River mainstem as opposed to within tributary channels. Backwaters with fluid connection to the mainstem river channel were categorized as mainstem water. Backwaters completely disconnected from the mainstem were grouped with the tributary water. We created a water classification dataset from multispectral high resolution imagery. All processing steps were completed in ENVI + IDL 5.3 a product of Harris Geospatial Solutions (copyright 2017 Exelis Visual Information Solutions, Inc., a subsidiary of Harris Corporation) and ArcGIS 10.3 a product of ESRI (copyright 2017).

These data were compiled to assess the risk of erosion to archaeological site preservation. The objective of the study is to evaluate changes in archaeological site condition over time as a function of two geomorphology based conceptual models that evaluate the extent to which sites are potentially affected by 1) erosion from gullies, and 2) wind-driven (aeolian) supply of river-sourced sand, respectively. These data represent the results of two classification metrics, based on the two conceptual models, applied to a population of 362 archaeological sites over multiple decades. Both conceptual models numerically rank geomorphic conditions with class values of 1 representing the best potential for archaeological site preservation and larger number class values (e.g. 2, 3, 4...) representing lower potential for archaeological site preservation. These data were collected in Grand Canyon National Park using interpretation of aerial photography acquired between 1973 and 2021, and field investigations conducted between 2000 and 2022. These data were collected by the U.S. Geological Survey and the National Park Service. These data can be used to assess the extent to which sites are affected by erosion from gullies controlled by the base-level of the Colorado River. These data can be used to evaluate how the wind-driven (aeolian) supply of river-sourced sand, essential for covering archaeological sites and protecting them from erosion, has changed over time. These data can be used to assess potential downstream effects of Glen Canyon Dam operations on archaeological site preservation. These data can be used to assess the extent to which dam regulated flows have influenced gully establishment and development as well as availability of the supply of river-sourced sand for wind-driven (aeolian) transport at each of the 362 archaeological sites over the last 5 decades. Observed changes in geomorphic condition can be used to infer potential changes in archaeological site integrity associated with decreased potential for archaeological site preservation.

These data were compiled to assess the risk of erosion to archaeological site preservation. The objective of the study is to evaluate changes in archaeological site condition over time as a function of two geomorphology based conceptual models that evaluate the extent to which sites are potentially affected by 1) erosion from gullies, and 2) wind-driven (aeolian) supply of river-sourced sand, respectively. These data represent the results of two classification metrics, based on the two conceptual models, applied to a population of 362 archaeological sites over multiple decades. Both conceptual models numerically rank geomorphic conditions with class values of 1 representing the best potential for archaeological site preservation and larger number class values (e.g. 2, 3, 4...) representing lower potential for archaeological site preservation. These data were collected in Grand Canyon National Park using interpretation of aerial photography acquired between 1973 and 2021, and field investigations conducted between 2000 and 2022. These data were collected by the U.S. Geological Survey and the National Park Service. These data can be used to assess the extent to which sites are affected by erosion from gullies controlled by the base-level of the Colorado River. These data can be used to evaluate how the wind-driven (aeolian) supply of river-sourced sand, essential for covering archaeological sites and protecting them from erosion, has changed over time. These data can be used to assess potential downstream effects of Glen Canyon Dam operations on archaeological site preservation. These data can be used to assess the extent to which dam regulated flows have influenced gully establishment and development as well as availability of the supply of river-sourced sand for wind-driven (aeolian) transport at each of the 362 archaeological sites over the last 5 decades. Observed changes in geomorphic condition can be used to infer potential changes in archaeological site integrity associated with decreased potential for archaeological site preservation.

These spatial data represent alluvial deposits of the Colorado River and tributary deposits adjacent to the Colorado River in Grand Canyon National Park. The map covers the river corridor from Lees Ferry, Arizona to the confluence with Diamond Creek 225 miles (362 km) downstream. The alluvial deposits of the Colorado River are mapped as either sand or gravel based on surface composition and the sand deposits are further subdivided based on sandbar type (Schmidt, 1990; Mueller and others, 2018). The alluvial deposits are also subdivided based on whether they are bare sediment or covered by dense riparian vegetation. The tributary deposits consist primarily of tributary debris fans, which are coarse-grained material transported by tributary flash floods and debris flows (Webb and others, 1989). The source data for creating the alluvial and tributary deposit features were orthorectified, 25-cm resolution, color aerial photographs (described in Davis, 2012). The map units, represented as vector polygon features, were hand digitized on-screen with these images as a background base layer. The map depicts conditions at the time the base images were collected, which was May 2009 while the Colorado River was flowing at a steady flow of approximately 8,000 ft3/s (227 m3/s). In addition to mapping the deposits exposed above the water surface, the wetted channel was also mapped and subdivided based on general hydraulic characteristics. The primary distinction was between portions of the channel with only downstream flow at 8,000 ft3/s and portions of the channel with lateral flow separation zones, or eddies. The alluvial, channel, and tributary fan deposits are also grouped based on the debris-fan eddy complex unit (Schmidt and Rubin, 1995).

These spatial data represent alluvial deposits of the Colorado River and tributary deposits adjacent to the Colorado River in Grand Canyon National Park. The map covers the river corridor from Lees Ferry, Arizona to the confluence with Diamond Creek 225 miles (362 km) downstream. The alluvial deposits of the Colorado River are mapped as either sand or gravel based on surface composition and the sand deposits are further subdivided based on sandbar type (Schmidt, 1990; Mueller and others, 2018). The alluvial deposits are also subdivided based on whether they are bare sediment or covered by dense riparian vegetation. The tributary deposits consist primarily of tributary debris fans, which are coarse-grained material transported by tributary flash floods and debris flows (Webb and others, 1989). The source data for creating the alluvial and tributary deposit features were orthorectified, 25-cm resolution, color aerial photographs (described in Davis, 2012). The map units, represented as vector polygon features, were hand digitized on-screen with these images as a background base layer. The map depicts conditions at the time the base images were collected, which was May 2009 while the Colorado River was flowing at a steady flow of approximately 8,000 ft3/s (227 m3/s). In addition to mapping the deposits exposed above the water surface, the wetted channel was also mapped and subdivided based on general hydraulic characteristics. The primary distinction was between portions of the channel with only downstream flow at 8,000 ft3/s and portions of the channel with lateral flow separation zones, or eddies. The alluvial, channel, and tributary fan deposits are also grouped based on the debris-fan eddy complex unit (Schmidt and Rubin, 1995).

Samples of aeolian (wind-transported) sediment were collected between 2003 and 2010 at multiple locations along the Colorado River corridor within Grand Canyon National Park, Arizona. At each site, sediment being actively transported by wind were collected using a set of four vertically stacked passive samplers (Big Spring Number Eight [BSNE] sand traps). Sediment samples were collected from the traps during site visits separated by days to months. Sediment sample weights were analyzed at the U.S. Geological Survey (USGS) Grand Canyon Monitoring and Research Center laboratory in Flagstaff, Arizona. Sediment-sample weights may be used to calculate rates of aeolian sediment transport at each location. The USGS gratefully acknowledges sampling permission granted by Grand Canyon National Park.

These data are a surface water classification map of surface water in the riparian corridor of Grand Canyon between Glen Canyon and Pearce Ferry, Arizona, published in ESRI shapefile format. The map was classified from 0.2 m resolution, multispectral imagery (Sankey and others, 2024) and are the same spatial resolution as the imagery. In order to differentiate between the boundary between each river reach in Grand Canyon, the map is categorized with a water channel name, including the mainstem Colorado River or other major tributaries by name. Data analyses were performed using ENVI V.5.6.1 and IDL V8.8.1, a registered trademark of NV5 Global, Inc. and ArcGIS PRO 3.3.1, a product of Esri, Inc.

These data are classification maps of total riparian vegetation along the Colorado River in Grand Canyon from Glen Canyon Dam to Pearce Ferry in Arizona. The data are derived from interpretation of multispectral high resolution airborne imagery that was acquired in May 2013. The total vegetation data have the same 0.2-meter ground resolution as the imagery. These data have not undergone a statistical accuracy assessment, but they are based on methods that included image interpretation to exhaustively identify total vegetation which have been shown to produce very high classification accuracies and excellent correlation between maps of total vegetation produced by independent analysts and ground truth. The data represent total vegetation that is primarily green and photosynthetically active at the time of image acquisition, and do not necessarily represent vegetation at various stages of senescence or defoliated/dead vegetation that may still be rooted and standing.