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Research about upper Colorado River Basin

Source-linked reports with geographic coverage including upper Colorado River Basin.

5 recordsLinked to original sources
USGS2022

Tree rings reveal unmatched 2nd century drought in the Colorado River Basin

The ongoing 22 year drought in the Upper Colorado River Basin (UCRB) has been extremely severe, even in the context of the longest available tree-ring reconstruction of annual flow at Lees Ferry, Arizona, dating back to 762 CE. While many southwestern drought assessments have been limited to the past 1200 years, longer paleorecords of moisture variability do exist for the UCRB. Here, gridded drought-atlas data in the UCRB domain along with naturalized streamflow data from the instrumental period (1906–2021) are used in a K nearest neighbor (KNN) nonparametric algorithm to develop a streamflow reconstruction for the Lees Ferry gage starting in 1 CE. The reconstruction reveals a 2nd century drought unmatched in severity by the current drought or by well-documented medieval period droughts in the UCRB. Although data are sparse, analysis of individual long tree ring records and other paleoclimatic data also support the occurrence of an exceptional 2nd century drought.

Arizona, Colorado, New Mexico, Utah, Wyoming↗
USGS2021

How will baseflow respond to climate change in the Upper Colorado River Basin?

Baseflow is critical to sustaining streamflow in the Upper Colorado River Basin. Therefore, effective water resources management requires estimates of baseflow response to climatic changes. This study provides the first estimates of projected baseflow changes from historical (1984 – 2012) to thirty-year periods centered around 2030, 2050, and 2080 under warm/wet, median, and hot/dry climatic conditions using a hybrid statistical-deterministic baseflow model. Total baseflow supplied to the Lower Colorado River Basin may decline by up to 33%, although this value may increase in the near future by 6% under warm/wet conditions. The percentage of baseflow lost during in-stream transport is projected to increase by 1 - 5% relative to historical conditions. Results highlight that climate driven changes in high elevation hydrology have impacts on basin-wide water availability. Study results have implications for human and ecological water availability in one of the most heavily managed watersheds in the world.

Arizona, Colorado, New Mexico, Utah, Wyoming↗
USGS1987

Selected hydrologic and physical properties of Mesozoic formations in the Upper Colorado River Basin in Arizona, Colorado, Utah, and Wyoming: Excluding the San Juan Basin

Data for hydrologic and physical properties of Mesozoic formations in the Upper Colorado River Basin, excluding the San Juan Basin, have been collected by government agencies, private industry, property owners, and other sources. These data were compiled and analyzed so that they would be available for use by hydrologists, earth scientists, planners, and others. Five methods of data analysis are discussed. The results of these five methods are not directly comparable because of differences in the volume of an aquifer represented by each method. Aquifer tests represent the largest volume of an aquifer, specific capacity and drill-stem tests represent a smaller volume, slug-injection tests represent a still smaller volume, and laboratory tests represent the smallest volume. Because they represent large volumes of an aquifer, aquifer tests were considered to give the best estimates of hydrologic characteristics. Laboratory data for permeability to air and hydraulic conductivity were determined to be related by a simple power function.

Arizona, Colorado, Utah, Wyoming↗