Publications
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Improving groundwater model calibration with repeat microgravity measurements
Groundwater-flow models depend on hydraulic head and flux observations for evaluation and calibration. A different type of observation—change in storage measured using repeat microgravity—can also be used for parameter estimation by simulating the expected change in gravity from a groundwater model and including the observation misfit in the objective function. The method is demonstrated using new
Authors
Jeffrey Kennedy, Libby M. Kahler, Jacob E. Knight, Joshua D. Larson
Preliminary geohydrologic assessment of Buenos Aires National Wildlife Refuge, Altar Valley, southeastern Arizona
The Buenos Aires National Wildlife Refuge is located in the southern part of Altar Valley, southwest of Tucson in southeastern Arizona. The primary water-supply well at the Buenos Aires National Wildlife Refuge has experienced a two-decade decrease in groundwater levels in the well, as have other wells in the southern part of Altar Valley. In part to understand this trend, a study was undertaken b
Authors
Sandra J. Owen-Joyce, James B. Callegary, Amy Elizabeth Rosebrough
Developing climate resilience in aridlands using rock detention structures as green infrastructure
The potential of ecological restoration and green infrastructure has been long suggested in the literature as adaptation strategies for a changing climate, with an emphasis on revegetation and, more recently, carbon sequestration and stormwater management. Tree planting and “natural” stormwater detention structures such as bioswales, stormwater detention basins, and sediment traps are popular appr
Authors
Laura M. Norman, Benjamin L. Ruddell, Deborah Tosline, Michael Fell, Blair P. Greimann, Jay Cederberg
Assessing potential groundwater-level declines from future withdrawals in the Hualapai Valley, northwestern Arizona
A numerical groundwater flow model of the Hualapai Valley Basin in northwestern Arizona was developed to assist water-resource managers in understanding the potential effects of projected groundwater withdrawals on groundwater levels in the basin. The Hualapai Valley Hydrologic Model (HVHM) simulates the hydrologic system for the years 1935 through 2219, including future withdrawal scenarios that
Authors
Jacob E. Knight, Bruce Gungle, Jeffrey R. Kennedy
Occurrence, fate, and transport of aerially applied herbicides to control invasive buffelgrass within Saguaro National Park Rincon Mountain District, Arizona, 2015–18
The spread of the invasive and fire-adapted buffelgrass (Cenchrus ciliaris L.) threatens desert ecosystems by competing for resources, increasing fuel loads, and creating wildfire connectivity. The Rincon Mountain District of Saguaro National Park addressed this natural resource threat with the use of glyphosate-based herbicides (GBHs). In 2010, the Rincon Mountain District initiated an aerial res
Authors
Nicholas V. Paretti, Kimberly R. Beisner, Bruce Gungle, Michael T. Meyer, Bethany K. Kunz, Edyth Hermosillo, Jay R. Cederberg, Justine P. Mayo
Estimation of dissolved-solids concentrations using continuous water-quality monitoring and regression models at four sites in the Yuma area, Arizona and California, January 2017 through March 2019
Multiple linear regression models were developed to estimate dissolved-solids concentrations in water at four sites in the Yuma area between Imperial Dam, Arizona and California and the southerly international boundary with Mexico at San Luis, Arizona. Continuous and discrete water-quality data were collected at gaging stations in the Colorado River upstream from Imperial Dam, Arizona-California,
Authors
Jay R. Cederberg, Nicholas V. Paretti, Alissa L. Coes, Edyth Hermosillo, Lucia Andrade
Historical floods and geomorphic change in the lower Little Colorado River during the late 19th to early 21st centuries
The Little Colorado River is a major tributary to the Colorado River with a confluence at the boundary between Marble and Grand Canyons within Grand Canyon National Park, Arizona. The bedrock gorge of the lower Little Colorado River is home to the largest known population of Gila cypha (humpback chub), an endangered fish endemic to the Colorado River Basin. Channel conditions might affect the spaw
Authors
Joel A. Unema, David J. Topping, Keith Kohl, Michael J. Pillow, Joshua J. Caster
Groundwater and surface-water data from the C-aquifer monitoring program, Northeastern Arizona, 2012–2019
The Coconino aquifer (C aquifer) is a regionally extensive multiple-aquifer system supplying water for municipal, agricultural, and industrial use in northeastern Arizona, northwestern New Mexico, and southeastern Utah. This report focuses on the C aquifer in the arid to semi-arid area between St. Johns, Ariz., and Flagstaff, Ariz., along the Interstate-40 corridor where an increase in groundwater
Authors
Casey J.R. Jones, Michael J. Robinson
Preliminary assessment of carbon and nitrogen sequestration potential of wildfire-derived sediments stored by erosion control structures in forest ecosystems, southwest USA
The role of pyrogenic carbon (PyC) in the global carbon cycle is still incompletely characterized. Much work has been done to characterize PyC on landforms and in soils where it originates or in “terminal” reservoirs such as marine sediments. Less is known about intermediate reservoirs such as streams and rivers, and few studies have characterized hillslope and in-stream erosion control structures
Authors
James B. Callegary, Laura M. Norman, Christopher J. Eastoe, Joel B. Sankey, Ann Youberg
Groundwater conditions and trends, 2009–19, Saipan, Commonwealth of the Northern Mariana Islands
Groundwater is the primary source of municipal water for Saipan. Nearly all groundwater for the municipal water supply is withdrawn from a freshwater-lens system with a limited amount of freshwater that is susceptible to saltwater intrusion. The status of Saipan’s groundwater resources has not been thoroughly assessed since 2003. The U.S. Geological Survey—in cooperation with the Office of Grants
Authors
Jackson N. Mitchell, Todd K. Presley, Robert L. Carruth
Groundwater, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona—2016–2018
The Navajo (N) aquifer is the primary source of groundwater in the 5,400-square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in the Black Mesa area because of continued water requirements for industrial and municipal use by a growing population and because of its arid climate. Precipitation in the area typically ranges from less than 6 to more than 16 i
Authors
Jon P. Mason
Enumerating white-tailed deer using unmanned aerial vehicles
The white‐tailed deer (Odocoileus virginianus) is an ecologically important species in forests of North America. Effective management of forests requires accurate, precise estimates of deer population abundance to plan and justify management actions. Spotlight surveys in combination with distance sampling are a common method of estimating deer population abundance; however, spotlight surveys are k
Authors
Todd M. Preston, Mark L. Wildhaber, Nicholas S. Green, Janice L. Albers, Geoffrey P. Debenedetto