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These data were compiled during a laboratory experiment showing the turbidity response to increasing silt and clay concentration. The sediment used for the laboratory experiment was collected in the Grand Canyon study area, from the bank of the Little Colorado River, approximately 1 kilometer upstream from its confluence with the Colorado River. The sediment was passed through a 63 µm sieve to isolate the silt-and-clay-size fraction. The silt and clay was completely dried in an oven (at 105 degrees Celsius for 12 hours), weighed, mechanically disaggregated, and added in stages to a measured volume of water to calculate concentration. The sediment was kept in suspension with an electric stirrer and turbidity was...
We examined the biogeography of aquatic and semiaquatic Heteroptera (ASH) in the Grand Canyon (GC) ecoregion (GCE) on and adjacent to the southern Colorado Plateau. We report 89 ASH taxa in 86 species, 37 genera, and 14 families in the GCE, including 54 ASH taxa detected within or on the rims of GC and its major tributaries, a fauna 3.8-fold greater than previously reported. We tested 2 groups of biogeographic hypotheses to account for this high level of diversity, demonstrating an underlying pattern of mixed biogeographic affinity and strong landform-climate effects. Equal numbers of ASH taxa were derived from allochthonous (neotropical and nearctic) sources and autochthonous (range-centered) sources. A negative...
These data were compiled for investigating the relationship between acoustic backscattering by riverbeds composed of various riverbed substrates (bed sediment), and for developing and testing a probabilistic model for substrate classification based on high-frequency multibeam acoustic backscatter. The model is described in Buscombe et al. (2017). The data consist of various quantities on coincident grids, from various sites along the Colorado River in Grand Canyon, including water depth, bed roughness, the area (or footprint) of the acoustic beam, unfiltered and filtered backscatter magnitude, sediment classification (for each location, 1 of 5 sediment classes in a categorical scheme), and the probabilities for...
This ESRI geodatabase consists of 5 feature datsets with 23 individual polygon feature classes and two raster datasets. A master campsite polygon feature class represents the boundaries of campsites identified in the 1973, 1984, and 1991 campsite inventories of the Colorado River corridor in Grand Canyon, Arizona. The other polygon feature classes represent camp locations along the Colorado River corridor in Grand Canyon, Arizona during different survey periods using different surveying techniques. The raster datasets represent sub-aerial and sub-surface sandbar surfaces at 37 long term-monitoring sites between Lees Ferry and Diamond Creek, Arizona in Grand Canyon National Park, measured in September and October...
The RCMAP (Rangeland Condition Monitoring Assessment and Projection) dataset quantifies the percent cover of rangeland components across the western U.S. using Landsat imagery from 1985-2021. The RCMAP product suite consists of nine fractional components: annual herbaceous, bare ground, herbaceous, litter, non-sagebrush shrub, perennial herbaceous, sagebrush, shrub, and tree, in addition to the temporal trends of each component. Several enhancements were made to the RCMAP process relative to prior generations. First, we have trained time-series predictions directly from 331 high-resolution sites collected from 2013-2018 from Assessment, Inventory, and Monitoring (AIM) instead of using the 2016 “base” map as an intermediary....
These data represent total vegetation and surface water along approximately 12 kilometers of the Paria River upstream from the confluence of the Colorado River at Lees Ferry, Arizona. They are derived from airborne, multispectral imagery obtained in late May 2009, 2013, and 2021, collected with a push-broom sensor with 4 spectral bands depicting Blue, Green, Red and Near-Infrared wavelengths at a spatial resolution of 20 centimeters. The vegetation classification data were created using a supervised classification algorithm provided by Harris Geospatial in ENVI version 5.6.3 (Exelis Visual Information Solutions, Boulder, Colorado). The water data were created using a Green Normalized Difference Vegetation Index...
These data were compiled to create models that estimate entrainment rates and population growth rates of smallmouth bass below Glen Canyon Dam. Objective(s) of our study were to predict smallmouth bass entrainment rates and population growth under different future scenarios of Lake Powell elevations and management. These data represent parameters needed for associated models and data needed to produce figures. These data were collected from publicly available online sources including published papers and federal government datasets. These data were assembled by researchers from U.S. Geological Survey, Utah State University, Colorado State University, U.S. Fish and Wildlife Service. These data can be used to run...
This data release compiles the electron microprobe spot analyses of U, Th, and Pb concentrations in uraninite (U oxide) particles, and corresponding calculated age determinations, measured in samples of ore from two uranium-copper breccia pipe ore bodies, the Canyon (Pinyon Plain) and Hack II deposits. The U-rich samples that were analyzed typify the deposits hosted by solution-collapse breccia pipes in the Grand Canyon region of northwestern Arizona. Applying procedures outlined by Bowles (1990), the U, Pb, and Th measurements from each spot analysis were used to calculate a model age for the formation of each uraninite particle. The U, Pb, and Th analyses and calculated age determinations are provided as additional...
In May 2021, the Grand Canyon Monitoring and Research Center (GCMRC) of the U.S. Geological Survey’s (USGS), Southwest Biological Science Center (SBSC) acquired airborne multispectral high resolution data for the Colorado River in Grand Canyon in Arizona, USA. The imagery data consist of four bands (Band 1 – red, Band 2 – green, Band 3 – blue, and Band 4 – near infrared) with a ground resolution of 20 centimeters (cm). These image data are available to the public as 16-bit GeoTIFF files, which can be read and used by most geographic information system (GIS) and image-processing software. The spatial reference of the image data are in the State Plane (SP) map projection using the central Arizona zone (FIPS 0202)...
Climate change over the past century has altered vegetation community composition and species distributions across rangelands in the western United States. The scale and magnitude of climatic influences are largely unknown. We used fractional component cover data for rangeland functional groups and weather data from the 1985 to 2023 reference period in conjunction with soils and topography data to develop empirical models describing the spatio-temporal variation in component cover. To investigate the ramifications of future change across the western US, we extended models based on historical relationships over the reference period to model landscape effects based on future weather conditions from two emissions scenarios...
Lake Powell retains most of the phosphorus that it receives, leading to downstream phosphorus limitation. These data were compiled to examine controls on phosphorus cycling below Lake Powell in the Colorado River and from storm inputs from the Paria River. Objectives of our study were to determine how several forms of phosphorus, both organic and inorganic, were cycled under varying dissolved oxygen concentrations and pH, reflecting the range of values observed in the river over the years. These data represent nitrogen, phosphorus, calcium, and carbon concentrations, water quality parameters (pH, dissolved oxygen, temperature), sediment composition, total protein, and extracellular enzyme activity (alkaline phosphatase)....
These data were compiled for/to modeling efforts for U.S. Bureau of Reclamation National Environmental Policy Act (NEPA) analyses for the Colorado River in Grand Canyon, Arizona. Objective(s) of our study were to create revised monthly Lake Powell elevations and outflows from Bureau of Reclamation Colorado River Mid-term Modeling System (CRMMS) traces that incorporate the alternatives in the sEIS documents and indicate when potential actions may occur and how that changes water movement and storage. These data represent monthly hydrologies for Lake Powell: inflow, outflow, and elevation forecasts for 2024-2027, as well as volumes of water in outflows for different water mangement strategies in NEPA supplemental...
These data are comprised of measurements of gross alpha activity, gross beta activity, and radionuclide activities (isotopic U, isotopic Th, Ra-226) in small rodent bodies. Samples were collected at non-mining and U breccia pipe mining sites in various production stages, in the Grand Canyon watershed.
These data are comprised of histopathological analysis of liver and kidney tissues collected from small rodents collected in close proximity to brecchia pipe uranium mines in the Grand Canyon watershed.
These data are comprised of measurements of elements (e.g., uranium, cobalt, nickel, copper, zinc, cadmium, lead, etc.) in Canyon Mine containment pond invertebrate samples collected in calendar years 2017 and 2018.
These data are comprised of measurements of elements (e.g., uranium, cobalt, nickel, copper, zinc, cadmium, lead, etc.), major anions (chloride, nitrite+nitrate as nitrogen, sulfate, etc.), dissolved organic carbon, and general water quality characteristics in Canyon Mine containment pond water samples collected in calendar year 2019.
These data were compiled for an outreach article published in the Boatman's Quarterly Review, which is a magazine published by Grand Canyon River Guides Association. The objectives of our study was to describe the outcomes of the 2018-2020 Bug Flows experiment to a general audience. These data represent 10 years (2012-2021) of invertebrate data and 100 years (1921-2021) of flow data. These data were collected from the Colorado River in Glen Canyon National Recreation Area and Grand Canyon National Park. These data were collected by recreational river runners through a community science effort where we provided river runners with light trapping equipment to sample emergent aquatic insects each night of their expeditions....
These data were collected as part of a methodologial comparison for collecting riparian vegetation data. Two common methods for collecting vegetation data were used: line-point intercept and 1m2 ocular quadrats (visual cover estimates). At each site and transect, both methods were used to collect cover and composition data by four different observers. The same transects and quadrats were utilized for both methods and all observers. Field data collected included percent cover for total living foliar cover, each plant species encountered, litter, dead plant material that is still standing, and ground cover features (biological soil crust, rock, sand, and fine soil particles). Line-point intercept data were collected...
These data consist of species relative cover, percent cover of dead plant material, percent cover of soil and rock, and a variety of broad - and local- scale environmental variables. These data relate to sample sites along the Colorado River through Grand Canyon between Lees Ferry and river mile 245. The plant and ground cover data included here were originally collected as a part of annual vegetation monitoring by Grand Canyon Monitoring and Research Center. Environmental variables were either recorded in the field or obtained through other data sources. Species and ground cover data were collected in August and September 2014 at 96 randomly selected sample sites that were approximately evenly distributed along...
Types: Citation;
Tags: American Southwest,
Arizona,
Colorado River,
Environmental variables,
Grand Canyon,
View east and upriver toward Unkar Group of rocks, Cardenas Basalt sill (black), Bass Formation (light gray), Hakatai Shale (red), unconformably below overlying Cambrian Tapeats Sandstone, from south side of river mile 134.8.
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