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Incision rates of the Colorado River are integral to understanding the development of the Colorado Plateau. Here we calculate episodic incision rates of the Colorado River based on absolute ages of two levels of Quaternary deposits adjacent to Glen Canyon, Utah, along the north flank of Navajo Mountain. Minimum surface ages are determined by a combination of cosmogenic radionuclide surface exposure ages, uranium series and soil-development formation times. Bedrock incision rates of the Colorado River between c. 500 ka and c. 250 ka, and c. 250 ka to present are c. 0·4 m ka−1 and c. 0·7 m ka−1, respectively. These rates are more than double the rates reported in the Grand Canyon, suggesting that the Colorado...
Beavers (Castor canadensis Kuhl) can influence the competitive dynamics of plant species through selective foraging, collection of materials for dam creation, and alteration of hydrologic conditions. In the Grand Canyon National Park, the native Salix gooddingii C.R.Ball (Goodding?s willow) and Salix exigua Nutt. (coyote willow) are a staple food of beavers. Because Salix competes with the invasive Tamarix ramosissima Ledeb., land mangers are concerned that beavers may cause an increase in Tamarix through selective foraging of Salix. A spatial analysis was conducted to assess whether the presence of beavers correlates with the relative abundance of Salix and Tamarix. These methods were designed to detect a system-wide...
The Colorado River system exhibits the characteristics of a heavily over-allocated or ?closing water system?. In such systems, development of mechanisms to allow resource users to acknowledge interdependence and to engage in negotiations and agreements becomes necessary. Recently, after a decade of deliberations and environmental assessments, the Glen Canyon Dam Adaptive Management Program (GCDAMP) was established to monitor and analyze the effects of dam operations on the Grand Canyon ecosystem and recommend adjustments intended to preserve and enhance downstream physical, cultural and environmental values. The Glen Canyon Dam effectively separates the Colorado into its lower and upper basins. Dam operations and...
In many interstate river basins, the institutional arrangements for the governance and management of the shared water resource are not adequately designed to effectively address the many political, legal, social, and economic issues that arise when the demands on the resource exceed the available supplies. Even under normal hydrologic conditions, this problem is frequently seen in the Colorado River Basin. During severe sustained drought, it is likely that the deficiencies of the existing arrangements would present a formidable barrier to an effective drought response, interfering with efforts to quickly and efficiently conserve and reallocate available supplies to support a variety of critical needs. In the United...
Frequent and persistent droughts exacerbate the problems caused by the inherent scarcity of water in the semiarid to arid parts of the southwestern United States. The occurrence of drought is driven by climatic variability, which for years before about the beginning of the 20th century in the Southwest must be inferred from proxy records. As part of a multidisciplinary study of the potential hydrologic impact of severe sustained drought on the Colorado River, the physical basis and limitations of tree rings as indicators of severe sustained drought are reviewed, and tree-ring data are analyzed to delineate a “worst-case� drought scenario for the Upper Colorado River Basin (UCRB). Runs analysis of a 121-site...
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The Colorado River system in southern Utah and northern Arizona is continuing to adjust to the baselevel fall responsible for the carving of the Grand Canyon. Estimates of bedrock incision rates in this area vary widely, hinting at the transient state of the Colorado and its tributaries. In conjunction with these data, we use longitudinal profiles of the Colorado and tributaries between Marble Canyon and Cataract Canyon to investigate the incision history of the Colorado in this region. We find that almost all of the tributaries in this region steepen as they enter the Colorado River. The consistent presence of oversteepened reaches with similar elevation drops in the lower section of these channels, and their coincidence...
Environmental flows have become important restoration tools on regulated rivers. However, environmental flows are often constrained by other demands within the river system and thus typically are comprised of smaller water volumes than the natural flows they are meant to replace, which can limit their functional efficacy. We review environmental flow programs aimed at restoring riparian vegetation on four arid zone rivers: the Tarim River in China; the Bill Williams River in Arizona, U.S.; the delta of the Colorado River in Mexico; and the Murrumbidgee River in southern Australia. Our goal is to determine what worked and what did not work to accomplish restoration goals. The lower Tarim River in China formerly formed...
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The vegetation units on this map were determined through a series of image processing steps including unsupervised classification, ecological modeling and stereoscopic interpretation of aerial photographs supported by field sampling and ecological analysis. The vegetation boundaries were identified on the photographs by means of the photographic signature and collateral information on slope, hydrology, geography, and vegetation in accordance with the Standardized National Vegetation Classification System (October 1995). The mapped vegetation reflects conditions that existed during the specific year and season that the aerial photographs were taken. There is a margin of error inherent in the use of aerial photographs....
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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...
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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...
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These data were compiled to demonstrate new predictive mapping approaches and provide comprehensive gridded 30-meter resolution soil property maps for the Colorado River Basin above Hoover Dam. Random forest models related environmental raster layers representing soil forming factors with field samples to render predictive maps that interpolate between sample locations. Maps represented soil pH, texture fractions (sand, silt clay, fine sand, very fine sand), rock, electrical conductivity (ec), gypsum, CaCO3, sodium adsorption ratio (sar), available water capacity (awc), bulk density (dbovendry), erodibility (kwfact), and organic matter (om) at 7 depths (0, 5, 15, 30, 60, 100, and 200 cm) as well as depth to restrictive...
Tags: Arizona, Colorado, Colorado River, Colorado River Basin, Colorado River Basin above Hoover Dam, All tags...
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These data were compiled to demonstrate new predictive mapping approaches and provide comprehensive gridded 30-meter resolution soil property maps for the Colorado River Basin above Hoover Dam. Random forest models related environmental raster layers representing soil forming factors with field samples to render predictive maps that interpolate between sample locations. Maps represented soil pH, texture fractions (sand, silt clay, fine sand, very fine sand), rock, electrical conductivity (ec), gypsum, CaCO3, sodium adsorption ratio (sar), available water capacity (awc), bulk density (dbovendry), erodibility (kwfact), and organic matter (om) at 7 depths (0, 5, 15, 30, 60, 100, and 200 cm) as well as depth to restrictive...
Tags: Arizona, Colorado, Colorado River, Colorado River Basin, Colorado River Basin above Hoover Dam, All tags...
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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...
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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...
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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...
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These data were compiled for a manuscript in which 1) we develop a water temperature model for the major river segments and tributaries of the Colorado River basin, including the Colorado, Green, Yampa, White, and San Juan rivers; 2) we link modeled water temperature to fish population data to predict the probability native and nonnative species will be common in the future in a warming climate; and 3) assess the degree to which dams create thermal discontinuity in summer in river segments across the western US. Per goal #1, we developed a water temperature model using data spanning 1985-2015 that predicts water temperature every 1 mile (1.6-km) in rivers both now and in the future due to the potential influence...
Tags: Aquatic Biology, Arizona, Arkansas River basin, Black Rocks, Colorado, All tags...
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This metadata record describes the materials contained in stake folder 1506. Stake 1506 is located at latitude 36.38585, longitude -112.63963. This location was photographed in the following years: 1909 (no physical image) and 1990. The materials associated with this item include original best quality images from each repeat date (preserved as digitized film images or in some cases digitized print photographs, depending on availability), scanned film envelopes with camera metadata, records of repeat photography sheets, and all field notes and/or camera notes associated with this stake. All attachments follow the following naming convention: stake_date_material_type_Kanab. Some stakes will have multiple materials...


map background search result map search result map Episodic incision of the Colorado River in Glen Canyon, Utah Rapid incision of the Colorado River in Glen Canyon - insights from channel profiles, local incision rates, and modeling of lithologic controls Colorado National Monument Vegetation Mapping Project - Spatial Vegetation Data Riparian Vegetation and Environmental Variables, Colorado River, 2014—Data USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 1506 Geomorphology and Campsite Data, Colorado River, Marble and Grand Canyon, Arizona Laboratory experiment data—turbidity response to increasing silt and clay concentration Acoustic backscatter - Data and Python Code Riparian vegetation data used for comparing sampling methods along the Colorado River, Grand Canyon, Arizona Predictive soil property map: Sodium adsorption ratio Predictive soil property map: Very fine sand content Water temperature models, data and code for the Colorado, Green, San Juan, Yampa, and White rivers in the Colorado River basin USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010: Stake 1506 Riparian vegetation data used for comparing sampling methods along the Colorado River, Grand Canyon, Arizona Colorado National Monument Vegetation Mapping Project - Spatial Vegetation Data Episodic incision of the Colorado River in Glen Canyon, Utah Geomorphology and Campsite Data, Colorado River, Marble and Grand Canyon, Arizona Rapid incision of the Colorado River in Glen Canyon - insights from channel profiles, local incision rates, and modeling of lithologic controls Riparian Vegetation and Environmental Variables, Colorado River, 2014—Data Laboratory experiment data—turbidity response to increasing silt and clay concentration Acoustic backscatter - Data and Python Code Predictive soil property map: Sodium adsorption ratio Predictive soil property map: Very fine sand content Water temperature models, data and code for the Colorado, Green, San Juan, Yampa, and White rivers in the Colorado River basin