Search USGS⌕ Search

Geology topics

W. F. Hardt

Publications and source records attributed to W. F. Hardt.

6 recordsLinked to original sources
USGS1974

Hydrologic analysis of the Mojave River, California, using a mathematical model

The channel of the Mojave Rive'r in California is normally dry and is highly permeable over much of its length, and large quantities of water from natural floodflows in the channel infiltrate through the channel bed to the underlying ground-water body. From 1930 to 1972 only 18 floods at The Forks produced flow at Barstow, 55 miles (88 kilometres) downstream from The Forks. Peak discharges at Barstow from these floods ranged from 180 cubic feet per second (5 cubic metres per second) in 1967 to 64,300 cubic feet per second (1,820 cubic metres per second) in 1938. Total stream infiltration, primarily as ground-water recharge, ranged from 3,600 acre-feet (4.40 cubic hectometres) in 1935 to 50,400 acre-feet (62.1 cubic hectometres) in 1969 between The Forks and Victorville and from about 7,000 acre-feet (8.61 cubic hectometres) in 1935 to 128,000 acre-feet (158 cubic hectometres) in 1969 between Victorville and Barstow. The Mojave Water Agency is considering the use of the channel of the river to convey water imported from northern California through Silverwood Reservoir (5 miles or 8 kilometres upstream from The Forks) downstream to the Barstow area. The imported water would be used to replenish aquifers underlying the Barstow area. A mathematical model was developed that simulates the advance of discharge down the initially dry channel of the Mojave River, and the model was used to evaluate the potential of the channel to move imported water downstream to Barstow. Results of simulation by modeling indicate that the channel of the Mojave River can be used to efficiently convey imported water to Barstow only when the absorption capacity of the channel has been reduced by an antecedent flood. The volume of imported water that can reach Barstow depends on the volume and duration of the antecedent flood, on the volume of imported water released trom Silverwood Reservoir, and on the rate at which imported water is released. A release of 20,000 acre-feet (24.6 cubic hectometres) of imported water may produce at Barstow a maximum volume of imported water of 2,500, 8,000, 11,000, or 15,000 acre-feet (3.08, 9.86, 13.6, or 18.4 cubic hectometres) for a release rate of 500, 750, 1,000, or 2,000 cubic feet per second (14.2, 21.2, 28.3, or 56.8 cubic metres per second). For planning purposes in evaluating some of the hydraulic effects of recharge on the aquifer, a simulation of the aquifer near the Barstow area using an electrical analog model showed that a combination of no pumping and a yearly recharge of 5,000 acre-feet (6.17 cubic hectometres) for 10 years could raise ground-water levels at least 10 feet (3 metres) over an area of about 10 square miles (25 square kilometres). To obtain the water-level changes due to the combined effects of pumping and recharge, the above water-level changes should be superimposed on the separate effects of pumping.

California↗
USGS1969

Regional hydrogeology of the Navajo and Hopi Indian Reservations, Arizona, New Mexico, and Utah, with a section on vegetation

The Navajo and Hopi Indian Reservations have an area of about 25,000 square miles and are in the south-central part of the Colorado Plateaus physiographic province. The reservations are underlain by sedimentary rocks that range in age from Cambrian to Tertiary, but Permian and younger rocks are exposed in about 95 percent of the area. Igneous and metamorphic basement rocks of Precambrian age underlie the sedimentary rocks at depths ranging from 1,000 to 10,000 feet. Much of the area is mantled by thin alluvial, eolian, and terrace deposits, which mainly are 10 to 50 feet thick. The Navajo country was a part of the eastern shelf area of the Cordilleran geosyncline during Paleozoic and Early Triassic time and part of the southwestern shelf area of the Rocky Mountain geosyncline in Cretaceous time. The shelf areas were inundated frequently by seas that extended from the central parts of the geosynclines. As a result, complex intertonguing and rapid facies changes are prevalent in the sedimentary rocks and form some of the principal controls on the ground-water hydrology. Regional uplift beginning in Late Cretaceous time , destroyed. the Rocky Mountain geosyncline and formed the structural basius that influenced sedimentation and erosion throughout Cenozoic time.

Arizona, New Mexico, Utah↗
USGS1966

Salinity of the ground water in western Pinal County, Arizona

The chemical quality of the ground water in western Pinal County is nonuniform areally and stratigraphically. The main areas of highly mineralized water are near Casa Grande and near Coolidge. Striking differences have been noted in the quality of water from different depths in the same well. Water from one well, (D-6-7) 25cdd, showed an increase in chloride content from 248 ppm (parts per million) at 350 feet below the land surface to 6,580 ppm at 375 feet; the concentration of chloride increased to 10,400 ppm at 550 feet below the land surface. This change was accompanied by an increase in the total dissolved solids as indicated by conductivity measurements. The change in water quality can be correlated with sediment types. The upper and lower sand and gravel units seem to yield water of better quality than the intermediate silt and clay unit. In places the silt and clay unit contains zones of gypsum and common table salt. These zones yield water that contains large amounts of the dissolved minerals usually associated with water from playa deposits. Highly mineralized ground water in an area near Casa Grande has moved southward and westward as much as 4 miles. Similar water near Coolidge has moved a lesser distance. Good management practices and proper use of soil amendments have made possible the use of water that is high in salinity and alkali hazard for agricultural purposes in western Pinal County. The fluoride content of the ground water in western Pinal County is usually low; however, water from wells that penetrate either the bedrock or unconsolidated sediments that contain certain volcanic rocks may have as much as 9 ppm of fluoride.

Water Supply Paper↗
USGS1965

Description and analysis of the geohydrologic system in western Pinal County, Arizona

Western Pinal County is between Phoenix and Tucson in the Basin and Range physiographic province of southern Arizona and consists of about 2,000 square miles of valley floor with low relief surrounded by mountains. It is the second largest agricultural area in the State, and about 25 percent of the ground water pumped in the State is from this area. The study area has been divided into four parts. Three of these--the Casa Grande-Florence area, the Eloy area, and the Stanfield-Maricopa area--are in the lower Santa Cruz basin; the fourth--the Gila River area--is a long narrow strip along the Gila River from the Ashurst-Hayden Dam to the confluence of the Gila and Santa Cruz Rivers. The project was undertaken to provide a better understanding of the ground-water supply in relation to the present and potential water use in this area of extensive ground-water development. The arid climate of western Pinal County--combining high temperatures and low humidity--causes most of the precipitation to be returned to the atmosphere by evapotranspiration, which leaves only a very small part for recharge to the ground-water reservoir. The computed potential evapotranspiration--44. 97 inches--is five times greater than the average precipitation. In general, the subsurface materials in western Pinal County are unconsolidated alluvial deposits underlain by consolidated alluvium and crystalline rocks and bounded by mountains consisting of crystalline and minor sedimentary rocks. The crystalline and sedimentary rocks of the mountains are not known to be water bearing in western Pinal County. The impermeable rocks underlying the basin are called the hydrologic bedrock unit in this report. Although the unit may consist of several different rock types, the distinction between them is relatively unimportant in this study because none of them yield appreciable amounts of water. The lower Santa Cruz basin in western Pinal County is divided into two sections by a buried ridge of the hydrologic bedrock unit, referred to in this report as the Casa Grande ridge. The ridge trends in a north-south direction from the Sacaton to the Silver Reef Mountains. The unconsolidated deposits constitute the main storage reservoir for ground water in western Pins/ County. The deposits are divided into four units---the local gravel unit, the lower sand and gravel unit, the silt and clay unit, and the upper sand and gravel unit--all of which are major water-yielding units except the silt and clay unit. The local gravel unit, which is present only in the western section of the lower Santa Cruz basin, ranges in thickness from 0 to nearly 1,000 feet and is generally a productive aquifer. The lower sand and gravel unit, Which is a heterogeneous mixture of sand, gravel, and clay, ranges in thickness from 0 to about 500 feet. Where the lower sand and gravel unit is overlain by the silt and clay unit, it generally contains water under artesian conditions; where it is not overlain by the silt and clay unit, it is indistinguishable from the upper sand and gravel unit, and the water is under water-table conditions. The silt and clay unit is the least permeable deposit of the unconsolidated alluvium, and ranges in thickness from 0 to about 2, 000 feet. Generally it is less productive than the other units of the unconsolidated alluvium, although it yields moderate amounts of water from numerous thin stringers and lenses of highly permeable sand and gravel. The upper sand and gravel unit is at the land surface in most of the area; it ranges in thickness from less than 50 to about 600 feet. The unit has the highest average permeability of all the unconsolidated alluvial units; however, the permeability of the unit varies vertically and laterally, which results in a wide range of well yields. As of 1964, the static water levels in most wells in the basin were still in the upper sand and gravel unit. However, the unit is being dewatered in most of the basin, and water levels in

Open-File Report↗