Publications

The hydrogeologic system in the Sierra Vista subwatershed of the Upper San Pedro Basin in southeastern Arizona was investigated for the purpose of developing a better understanding of stream-aquifer interactions. The San Pedro River is an intermittent stream that supports a narrow corridor of riparian vegetation. Withdrawal of ground water will result in reduced discharge from the basin through re

Aquifer storage was monitored using gravity methods in the Lower Canada del Oro subbasin from 1996 through 1998 to determine areas of infiltration and amounts of recharge along the Canada del Oro Wash after major surface flow and to estimate aquifer-storage change and specific-yield values for the regional aquifer.  Both purposes were addressed by periodic monitoring of changes in aquifer storage

Ground-water quality data (1917-96) from 772 wells in 16 alluvial basins that have minimal urban development were used to determine the effect of nonurban factors on ground-water quality in south- central Arizona. Characterization of the spatial variability of ground-water quality within and among alluvial basins that have minimal urban development will provide a baseline to which water- quality p

No abstract available.

No abstract available.

The Black Mesa monitoring program is designed to document long-term effects of ground-water from the N aquifer by industrial and municipal users. The N aquifer is the major source of water in the 5,400-square-mile Black Mesa area, and the ground water occurs under confined and unconfined conditions. Monitoring activities include continuous and periodic measurements of (1) ground-water pumpage fr

A release from Glen Canyon Dam during March-April 1996 was designed to test the effectiveness with which the riparian environment could be renewed with discharges greatly in excess of the normal powerplant-restricted maximum. Of primary concern was the rebuilding of sand deposits along the channel sides that are important to the flora and fauna along the river corridor and that provide the only

The availability of ground water is of extreme importance in areas, such as southern Arizona, where it is the main supply for agricultural, industrial, or domestic purposes. Where ground-water use exceeds recharge, monitoring is critical for managing water supplies. Typically, monitoring has been done by measuring water levels in wells; however, this technique only partially describes ground-water

The Central Arizona Basins study area in central and southern Arizona and northern Mexico is one of 60 study units that are part of the U.S. Geological Survey's National Water-Quality Assessment program. The purpose of this report is to describe the physical, chemical, and environmental characteristics that may affect water quality in the Central Arizona Basins study area and present an overview o

The United States Geological Survey Flagstaff Field Center was founded by the late Eugene Shoemaker in 1963 as a research site for the new science of planetary geology. Flagstaffs clear air and high elevation made it a desirable location for telescope observations of the Moon and planets and nearby Meteor Crater was a superb training ground for the Apollo astronauts. There, and in the volcanic fie

The Navajo Nation and Hopi Tribe of the Black Mesa area, Arizona, depend on ground water from the N aquifer to meet most tribal and industrial needs. Increasing use of this aquifer is creating concerns about possible adverse effects of increased ground-water withdrawals on the water resources of the region. A thorough understanding of the N aquifer is necessary to assess the aquifer's response to

The temporal-gravity method was used to estimate ground-water storage change and specific -yield values at wells near Rillito Creek, Tucson, Arizona, between early December 1992 and early January 1994. The method applies Newton's Law of Gravitation to measure changes in the local gravitational field of the Earth that are caused by changes in the mass and volume of ground water. Gravity at 50 stati