Arizona Water Science Center
Groundwater-storage change and land-surface elevation change in Tucson Basin and Avra Valley, south-central Arizona—2003–2016
The U.S. Geological Survey monitors groundwater-storage change and land-surface elevation change caused by groundwater withdrawal in Tucson Basin and Avra Valley—the two most populated alluvial basins within the Tucson Active Management Area. The Tucson Active Management Area is one of five active management areas in Arizona established by the...Carruth, Robert L.; Kahler, Libby M.; Conway, Brian D.
Filtering of periodic infiltration in a layered vadose zone: 2. Applications and a freeware screening tool
We have developed a screening tool to visualize and conceptualize the filtering properties of a layered vadose zone. Climate projections indicate that rainfall timing and magnitude may change and impact groundwater resources. This increases the importance of understanding how the vadose zone filters infiltration variability and ultimately affects...Dickinson, Jesse E.; Ferre, T.P.A
Findings and lessons learned from the assessment of the Mexico-United States transboundary San Pedro and Santa Cruz aquifers: The utility of social science in applied hydrologic research
Study RegionThis study region encompasses the Transboundary San Pedro and Santa Cruz aquifers which are shared between the states of Sonora (Mexico) and Arizona (US). Special regional considerations include a semi-arid climate, basin-fill aquifers with predominantly montane recharge areas, economic drivers in the mining, trade, and military...Callegary, James B.; Megdal, Sharon B.; Tapia Villaseñor, Elia María; Petersen-Perlman, Jacob D.; Minjárez Sosa, Ismael; Monreal, R.; Gray, F.; Grijalva Noriega, Francisco
Assessment of environmental flows in the middle Verde River watershed, Arizona
This report summarizes analyses of middle Verde River watershed environmental flows detailed in U.S. Geological Survey Scientific Investigations Report 2017-5100, “Preliminary synthesis and assessment of environmental flows in the middle Verde River watershed, Arizona," by N.V. Paretti, A.M.D. Brasher, S.L. Pearlstein, D.M. Skow, B. Gungle, and B....Gungle, Bruce W.; Paretti, Nicholas V.
Changes in Earth’s gravity reveal changes in groundwater storage
Changes in the amount of water stored in underground aquifers cause small changes in Earth’s gravitational field. The U.S. Geological Survey’s Southwest Gravity Program has developed methods for measuring terrestrial gravity changes with part-per-billion precision. The measurements allow scientists to map changes in groundwater storage and to...Kennedy, Jeffrey R.
Conceptual and numerical models of dissolved solids in the Colorado River, Hoover Dam to Imperial Dam, and Parker Dam to Imperial Dam, Arizona, California, and Nevada
Conceptual and numerical models were developed to understand and simulate monthly flow-weighted dissolved-solids concentrations in the Colorado River at Imperial Dam. The ability to simulate dissolved-solids concentrations at this location will help the Bureau of Reclamation satisfy the binational agreement on the volume and salinity of Colorado...Anning, David W.; Coes, Alissa L.; Mason, Jon P.
Effect of spatial and temporal scale on simulated groundwater recharge investigations
Hydrologic model input datasets such as climate, land use, elevation, soil, and geology information are available in a range of scales for use in water resources investigations. Smaller spatial and temporal scale input data allow groundwater recharge models to simulate more physically realistic processes and presumably result in more accurate...Tillman, Fred; Pruitt, Tom; Gangopadhyay, Subhrendu
Brackish groundwater and its potential as a resource in the southwestern United States
Secure, reliable, and sustainable water resources are fundamental to food production, energy independence, and the health of humans and ecosystems. But the large-scale development of fresh groundwater resources has stressed aquifers in some areas, causing declines in the amount of groundwater in storage and decreases in discharge to surface-water...Anning, David W.; Beisner, Kimberly R.; Paul, Angela P.; Stanton, Jennifer S.; Thiros, Susan A.
Geochemical characterization and modeling of regional groundwater contributing to the Verde River, Arizona between Mormon Pocket and the USGS Clarkdale gage
We use synoptic surveys of stream discharge, stable isotopes, and dissolved noble gases to identify the source of groundwater discharge to the Verde River in central Arizona. The Verde River more than doubles in discharge in Mormon Pocket over a 1.4 km distance that includes three discrete locations of visible spring input to the river and other...Beisner, Kimberly R.; Gardner, W. Payton; Hunt, Andrew G.
Managing salinity in Upper Colorado River Basin streams: Selecting catchments for sediment control efforts using watershed characteristics and random forests models
Elevated concentrations of dissolved-solids (salinity) including calcium, sodium, sulfate, and chloride, among others, in the Colorado River cause substantial problems for its water users. Previous efforts to reduce dissolved solids in upper Colorado River basin (UCRB) streams often focused on reducing suspended-sediment transport to streams, but...Tillman, Fred; Anning, David W.; Heilman, Julian A.; Buto, Susan G.; Miller, Matthew P.
Effect of river confinement on depth and spatial extent of bed disturbance affecting salmon redds
Human impacts on rivers threaten the natural function of riverine ecosystems. This paper assesses how channel confinement affects the scour depth and spatial extent of bed disturbance and discusses the implications of these results for salmon-redd disturbance in gravel-bedded rivers. Two-dimensional hydrodynamic models of relatively confined and...Christiana R. Czuba; Czuba, Jonathan A. ; Magirl, Christopher S.; Gendaszek, Andrew S.; Konrad, Christopher P.
Preliminary synthesis and assessment of environmental flows in the middle Verde River watershed, Arizona
A 3-year study was undertaken to evaluate the suitability of the available modeling tools for characterizing environmental flows in the middle Verde River watershed of central Arizona, describe riparian vegetation throughout the watershed, and estimate sediment mobilization in the river. Existing data on fish and macroinvertebrates were analyzed...Paretti, Nicholas V.; Brasher, Anne M. D.; Pearlstein, Susanna L.; Skow, Dena M.; Gungle, Bruce W.; Garner, Bradley D.