Geology Reports⌕ Search

Geology topics

W.M. Alley

Publications and source records attributed to W.M. Alley.

13 recordsLinked to original sources
USGS2011

Towards sustainable groundwater use: Setting long-term goals, backcasting, and managing adaptively

The sustainability of crucial earth resources, such as groundwater, is a critical issue. We consider groundwater sustainability a value‐driven process of intra‐ and intergenerational equity that balances the environment, society, and economy. Synthesizing hydrogeological science and current sustainability concepts, we emphasize three sustainability approaches: setting multigenerational sustainability goals, backcasting, and managing adaptively. As most aquifer problems are long‐term problems, we propose that multigenerational goals (50 to 100 years) for water quantity and quality that acknowledge the connections between groundwater, surface water, and ecosystems be set for many aquifers. The goals should be set by a watershed‐ or aquifer‐based community in an inclusive and participatory manner. Policies for shorter time horizons should be developed by backcasting, and measures implemented through adaptive management to achieve the long‐term goals. Two case histories illustrate the importance and complexity of a multigenerational perspective and adaptive management. These approaches could transform aquifer depletion and contamination to more sustainable groundwater use, providing groundwater for current and future generations while protecting ecological integrity and resilience.

Ground Water↗
USGS2006

Ground water for oil-shale development, Piceance Basin, Colorado

Vast deposits of oil shale are contained in the Piceance basin in northwestern Colorado. The basin may contain as much as 40 million acre-feet of stored water associated with these deposits, much of which may have to be drained for mining. Yet, most analyses of watersupply for oil-shale development have focused on surface water with only brief mention of ground water. This study used a synthetic streamflow model to investigate the effects of using conservative estimates of ground water on the required active storage capacity of a hypothetical reservoir on the White River. Results of the study indicate that use of ground water from mine drainage and/or auxiliary wells may have a significant impact on the size and timing of surface-water reservoirs. Thus, ground water may be an important source of supply, particularly during early development of an oil-shale industry. The study results strongly suggest that further investigations are needed on the physical availability of ground water as well as the institutional, legal and waterquality constraints on its use.

Ground Water↗
USGS2005

The Journey from Safe Yield to Sustainability

Safe-yield concepts historically focused attention on the economic and legal aspects of ground water development. Sustainability concerns have brought environmental aspects more to the forefront and have resulted in a more integrated outlook. Water resources sustainability is not a purely scientific concept, but rather a perspective that can frame scientific analysis. The evolving concept of sustainability presents a challenge to hydrologists to translate complex, and sometimes vague, socioeconomic and political questions into technical questions that can be quantified systematically. Hydrologists can contribute to sustainable water resources management by presenting the longer-term implications of ground water development as an integral part of their analyses.

Ground Water↗
USGS1991

A scientifically based nationwide assessment of groundwater quality in the United States

Beginning in 1986, the U.S. Geological Survey began an effort to develop a National Water-Quality Assessment Program. The basic premise underlying this initiative is that a better understanding of the quality of water resources across the country, both surface- and groundwater, is needed to develop effective programs and policies to meet the nation's water-quality concerns. The program will focus on water-quality conditions that are prevalent or large in scale, such as occur from nonpoint sources of pollution or from a high density of point sources. The design of the program is substantially different from the traditional approach of a diffuse national monitoring network. The major activities of the assessment program will be clustered within a set of hydrologic systems (river basins and aquifer systems), referred to as study units. In aggregate, the study units will account for a large part of the nation's water use and represent a wide range of settings across the country. Unique attributes of the program include: (1) the use of consistent study approaches, field and laboratory methods, water-quality measurements, and ancillary data measurements for all study units; (2) the development of a progressive understanding of water-quality conditions and trends in each study unit through long-term studies that rotate periods of intensive data collection and analysis with periods during which the assessment activities are less intensive; and (3) the focus of considerable effort on synthesizing results from among the study units to provide information on regional and national water-quality issues. ?? 1991 Springer-Verlag New York Inc.

Environmental Geology and Water Sciences↗
USGS1989

Well installation and documentation, and ground-water sampling protocols for the pilot National Water-Quality Assessment Program

Several pilot projects are being conducted as part of the National Water Quality Assessment (NAWQA) Program. The purpose of the pilot program is to test and refine concepts for a proposed full-scale program. Three of the pilot projects are specifically designed to assess groundwater. The purpose of this report is to describe the criteria that are being used in the NAWQA pilot projects for selecting and documenting wells, installing new wells, and sampling wells for different water quality constituents. Guidelines are presented for the selection of wells for sampling. Information needed to accurately document each well includes site characteristics related to the location of the well, land use near the well, and important well construction features. These guidelines ensure the consistency of the information collected and will provide comparable data for interpretive purposes. Guidelines for the installation of wells are presented and include procedures that need to be followed for preparations prior to drilling, the selection of the drilling technique and casing type, the grouting procedure, and the well-development technique. A major component of the protocols is related to water quality sampling. Tasks are identified that need to be completed prior to visiting the site for sampling. Guidelines are presented for purging the well prior t sampling, both in terms of the volume of water pumped and the chemical stability of field parameters. Guidelines are presented concerning sampler selection as related to both inorganic and organic constituents. Documentation needed to describe the measurements and observations related to sampling each well and treating and preserving the samples are also presented. Procedures are presented for the storage and shipping of water samples, equipment cleaning, and quality assurance. Quality assurance guidelines include the description of the general distribution of the various quality assurance samples (blanks, spikes, duplicates, and reference samples) that will be used in the pilot program. (Lantz-PTT)

Open-File Report↗
USGS1988

A summary of the U.S. Geological Survey National Water-Quality Assessment program

Beginning in 1986, the Congress appropriated funds for the U.S. Geological Survey to test and refine concepts for a National Water Quality Assessment Program. At present, the program is in a pilot phase with field studies occurring in seven areas around the Nation. In 1990, a committee of the National Academy of Sciences will complete an evaluation of the design and potential utility of the program. A decision about moving to full-scale implementation will be made upon completion of this evaluation. The program is intended to address a wide range of national water quality issues that include chemical contamination, acidification, eutrophication, salinity, sedimentation, and sanitary quality. The goals of the program are to: (1) provide nationally consistent descriptions of current water quality conditions for a large part of the Nation 's water resources; (2) define long-term trends (or lack of trends) in water quality; and (3) identify and describe the relations of both current conditions and trends in water quality to natural and human factors. This information will be provided to water managers, policy makers, and the public to provide an improved scientific basis for evaluating the effectiveness of water quality management programs and for predicting the likely effects of contemplated changes in land- and water-management practices. (USGS)

Open-File Report↗
USGS1986

Groundwater model of the Blue River basin, Nebraska-Twenty years later

Groundwater flow models have become almost a routine tool of the practicing hydrologist. Yet, surprisingly little attention has been given to true verification analysis of studies using these models. This paper examines predictions for 1982 of water-level declines and streamflow depletions that were made in 1965 using an electric analog groundwater model of the Blue River basin in southeastern Nebraska. Analysis of the model's predictions suggests that the analog model used too low an estimate of net groundwater withdrawals, yet overestimated water-level declines. The model predicted that almost all of the net groundwater pumpage would come from storage in the Pleistocene aquifer within the Blue River basin. It appears likely that the model underestimated the contributions of other sources of water to the pumpage, and that the aquifer storage coefficients used in the model were too low. There is some evidence that groundwater pumpage has had a greater than predicted effect on streamflow. Considerable uncertainty about the basic conceptualization of the hydrology of the Blue River basin greatly limits the reliability of groundwater models developed for the basin. The paper concludes with general perspectives on groundwater modeling gained from this post-audit analysis.

Nebraska↗
USGS1984

The Palmer Drought Severity Index: limitations and assumptions.

The structure of the Palmer Drought Severity Index (PDSI), which is perhaps the most widely used regional index of drought, is examined. The PDSI addresses two of the most elusive properties of droughts: their intensity and their beginning and ending times. Under certain conditions, the PDSI values are very sensitive to the criteria for ending an 'established' drought and precipitation during a month can have a very large effect on the PDSI values for several previous months. -from Author

Journal of Climate and Applied Meteorology↗
USGS1983

Mixed-station extension of monthly streamflow records.

Monthly streamflow records at a site are sometimes extended by exploiting interstation correlation of streamflow, often through simple linear regression with a base station having a long-term record. An approach is presented which selects a base station from among several in a region for filling in missing data. It differs from traditional approaches in that different stations can be selected as the base station to fill in different values. Application of the approach demonstrated large reductions in the streamflow prediction error for two sites in Colorado.-from ASCE Publications Information

Journal of Hydraulic Engineering↗
USGS1982

The relative importance of ground-water and surface-water supplies to oil-shale development, Piceance Basin, Colorado

A sensitivity analysis was perfomed of the required active storage capacity (VMAX) of a hypothetical reservoir on the White River to different assumptions about water demands for oil-shale development and the contributions from various sources of water. Estimates of VMAX were found to be sensitive to estimates of the supply of water available from the oil-shale aquifers. For example, the current estimate of average natural recharge to the oil-shale aquifers is approximately equal to the amount of water required by an oil-shale industry producing 250,000 barrels of oil per day and requiring 3 barrels of water per barrel of shale-oil produced. Estimates of VMAX were also sensitive to estimates of the supply of water available from the Colorado River and the requirements for downstream releases on the White River. The sensitivity of VMAX to use of water from the four main streams in the Piceance basin (Parachute, Roan, Piceance, and Yellow Creeks) was less than its sensitivity to these factors. Compared to the uncertainty in other factors, water-supply estimates are shown to be insensitive to uncertainty in evaporation estimates. A transient analysis was performed using a synthetic streamflow model to generate 500 equally likely periods of monthly inflows to the hypothetical reservoir. An oil-shale industry was assumed to expand from 0 to 1 million barrels of oil per day over a 30-year time period, and mine water was assumed to be available at an increasing rate that averaged one-half the current estimated natural recharge rate to the Piceance basin. Use of this mine water to supply part of the water demand resulted in reductions in surface-storage requirements (VMAX) on the order of 15-20 thousand acre-ft over many of the 500 streamflow sequences. (USGS)

Open-File Report↗
USGS1982

Distributed routing rainfall-runoff model; version II

A computer program of a watershed model for routing storm runoff through a branched system of pipes and (or) natural channels using rainfall as input is described. The model provides detailed simulation of storm-runoff periods selected by the user and a daily soil-moisture accounting between storms. A drainage basin is represented as a set of overland-flow, channel, and reservoir seqments which ,jointly describe the drainage features of the basin. Kinematic wave theory is used for routing flows over contributing overland-flow areas and through the channel network. A set of model segments can be arranged into a network that will represent many complex drainage basins. The model is intended primarily for application to urban watersheds, but may have limited applications to rural watersheds.

Open-File Report↗
USGS1982

Multi-event urban runoff quality model

A computer model is presented for simulating the quality of surface runoff from urban watersheds. The model can simulate impervious area, pervious area, and precipitation contributions to runoff quality as well as the effects of street sweeping and (or) detention storage. Within-storm variations of runoff quality are simulated for user-specified storm-runoff periods. Between these storms, a daily accounting of the accumulation and washoff of water-quality constituents on effective impervious areas is maintained. The time step of the within-storm simulations can range from 1 to 60 minutes. The model can be operated as a lumped-parameter model or as a distributed-parameter model. As a lumped-parameter model, no spatial variations in model parameters are accounted for, and input to the model requires flow hydrographs only at the outlet of the watershed. The outlet hydrographs can be either observed or simulated. As a distributed-parameter model, the model requires flow hydrographs at many points in the watershed, as defined by basin segmentation. These hydrographs will normally be simulated by the Distributed Routing Rainfall-Runoff Model. This report includes a presentation of the theory and limitations of the model, as well as a program listing, instructions for running the program, and example simulations.

Open-File Report↗