Search USGS⌕ Search

SEARCH · Search USGS

Results for “Journal for the American Water Resource Association”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
USGS2007

Analysis and modeling of long‐term stream temperatures on the Steamboat Creek Basin, Oregon: Implications for land use and fish habitat

Steamboat Creek basin is an important source of timber and provides crucial spawning and rearing habitat for anadromous steelhead trout ( Oncorhynchus mykiss ). Because stream temperatures are near the upper limit of tolerance for the survival of juvenile steelhead, the possible long‐term effect of clear‐cut logging on stream temperatures was assessed. Twenty‐year (1969–1989) records of summer stream temperature and flow from four tributaries and two reaches of Steamboat Creek and Boulder Creek (a nearby unlogged watershed) were analyzed. Logging records for the Steamboat Creek basin and air temperature records also were used in the analysis. A time‐series model of the components of stream temperature (seasonal cycle of solar radiation, air temperature, streamflow, an autoregressive term of order 1, and a linear trend variable) was fitted to the water‐temperature data. The linear trend variable was significant in all the fitted models except Bend Creek (a tributary fed by cool ground‐water discharge) and Boulder Creek. Because no trends in either climate (i.e., air temperature) or streamflow were found in the data, the trend variable was associated with the pre‐1969 loss and subsequent regrowth of riparian vegetation and shading canopies.

Oregon↗
USGS2022

Evaluation of select velocity measurement techniques for estimating discharge in small streams across the United States

Multiple instruments and methods exist for collecting discrete streamflow measurements in small streams with low flows, defined here as less than 5.7 m 3 /s (200 ft3/s). Included in the available methods are low-cost approaches that are infrequently used, in part, because their uncertainty is not well known. In this work, we evaluated the accuracy and suitability of three low-cost velocity measurement methods (surface float [SF], velocity head rod [VR], and rising body [RB]) and three conventional current meters (acoustic Doppler velocimeter, and mechanical Price type AA and Price Pygmy meters) relative to discharge calculated from stable artificial hydraulic controls. A total of 231 measurements were made by 20 individuals during 88 site visits to 24 sites in eight states. Accuracies were assessed for all methods and precision was evaluated for the low-cost methods. The median percent error was below 5% for conventional methods, and below 20% for the low-cost methods. The SF was the most accurate (median absolute percent error 14%) and precise (mean percent precision of 11%) low-cost method. The RB and VR, respectively, had 15% and 20% median absolute percent error and 29% and 12% mean percent precision. Results suggest that low-cost methods, when used appropriately, can be used to estimate discharge data under low flow conditions when measurements with conventional methods are not feasible and the associated accuracies meet end-user measurement objectives.

continental United States↗
USGS2014

Glyphosate and its degradation product AMPA occur frequently and widely in U.S. soils, surface water, groundwater, and precipitation

Glyphosate use in the United States increased from less than 5,000 to more than 80,000 metric tons/yr between 1987 and 2007. Glyphosate is popular due to its ease of use on soybean, cotton, and corn crops that are genetically modified to tolerate it, utility in no-till farming practices, utility in urban areas, and the perception that it has low toxicity and little mobility in the environment. This compilation is the largest and most comprehensive assessment of the environmental occurrence of glyphosate and aminomethylphosphonic acid (AMPA) in the United States conducted to date, summarizing the results of 3,732 water and sediment and 1,018 quality assurance samples collected between 2001 and 2010 from 38 states. Results indicate that glyphosate and AMPA are usually detected together, mobile, and occur widely in the environment. Glyphosate was detected without AMPA in only 2.3% of samples, whereas AMPA was detected without glyphosate in 17.9% of samples. Glyphosate and AMPA were detected frequently in soils and sediment, ditches and drains, precipitation, rivers, and streams; and less frequently in lakes, ponds, and wetlands; soil water; and groundwater. Concentrations of glyphosate were below the levels of concern for humans or wildlife; however, pesticides are often detected in mixtures. Ecosystem effects of chronic low-level exposures to pesticide mixtures are uncertain. The environmental health risk of low-level detections of glyphosate, AMPA, and associated adjuvants and mixtures remain to be determined.

Journal of the American Water Resources Associatio↗
USGS2007

Nutrient mass balance and trends, Mobile River Basin, Alabama, Georgia, and Mississippi

A nutrient mass balance - accounting for nutrient inputs from atmospheric deposition, fertilizer, crop nitrogen fixation, and point source effluents; and nutrient outputs, including crop harvest and storage - was calculated for 18 subbasins in the Mobile River Basin, and trends (1970 to 1997) were evaluated as part of the U.S. Geological Survey National Water Quality Assessment (NAWQA) Program. Agricultural nonpoint nitrogen and phosphorus sources and urban nonpoint nitrogen sources are the most important factors associated with nutrients in this system. More than 30 percent of nitrogen yield in two basins and phosphorus yield in eight basins can be attributed to urban point source nutrient inputs. The total nitrogen yield (1.3 tons per square mile per year) for the Tombigbee River, which drains a greater percentage of agricultural (row crop) land use, was larger than the total nitrogen yield (0.99 tons per square mile per year) for the Alabama River. Decreasing trends of total nitrogen concentrations in the Tombigbee and Alabama Rivers indicate that a reduction occurred from 1975 to 1997 in the nitrogen contributions to Mobile Bay from the Mobile River. Nitrogen concentrations also decreased (1980 to 1995) in the Black Warrior River, one of the major tributaries to the Tombigbee River. Total phosphorus concentrations increased from 1970 to 1996 at three urban influenced sites on the Etowah River in Georgia. Multiple regression analysis indicates a distinct association between water quality in the streams of the Mobile River drainage basin and agricultural activities in the basin.

Alabama, Georgia, Mississippi↗
USGS2007

Regression models of herbicide concentrations in outflow from reservoirs in the midwestern USA, 1992-1993

Reservoirs are used to store water for public water supply, flood control, irrigation, recreation, hydropower, and wildlife habitat, but also often store undesirable substances such as herbicides. The outflow from 76 reservoirs in the midwestern USA, was sampled four times in 1992 and four times in 1993. At least one herbicide was detected in 82.6 percent of all samples, and atrazine was detected in 82.1 percent of all samples. Herbicide properties; topography, land use, herbicide use, and soil type in the contributing drainage area; residence time of water in reservoirs; and timing of inflow, release, and rainfall all can affect the concentration of herbicides in reservoirs. A GIS was used to quantify characteristics of land use, agricultural chemical use, climatic conditions, topographic character, and soil type by reservoir drainage basins. Multiple linear and logistic regression equations were used to model mean herbicide concentrations in reservoir outflow as a function of these characteristics. Results demonstrate a strong association between mean herbicide concentrations in reservoir outflow and herbicide use rates within associated drainage basins. Results also demonstrate the importance of including soils and basin hydrologic characteristics in models used to estimate mean herbicide concentrations.

Journal of the American Water Resources Associatio↗
USGS2014

Reach-scale comparison of habitat and mollusk assemblages for select sites in the Clinch River with regional context

Several hypotheses, including habitat degradation and variation in fluvial geomorphology, have been posed to explain extreme spatial and temporal variation in Clinch River mollusk assemblages. We examined associations between mollusk assemblage metrics (richness, abundance, recruitment) and physical habitat (geomorphology, streambed composition, fish habitat, and riparian condition) at 10 sites selected to represent the range of current assemblage condition in the Clinch River. We compared similar geomorphological units among reaches, employing semi-quantitative and quantitative protocols to characterize mollusk assemblages and a mix of visual assessments and empirical measurements to characterize physical habitat. We found little to no evidence that current assemblage condition was associated with 54 analyzed habitat metrics. When compared to other sites in the Upper Tennessee River Basin (UTRB) that once supported or currently support mollusk assemblages, Clinch River sites were more similar to each other, representing a narrower range of conditions than observed across the larger geographic extent of the UTRB. A post-hoc analysis suggested stream size and average boundary shear stress at bankfull stage may have historically limited species richness in the UTRB (p < 0.001). Associations between mollusk assemblages and physical habitat in the UTRB and Clinch River currently appear obscured by other factors limiting richness, abundance, and recruitment.

Tennessee, Virginia↗
USGS2007

Problems and methods involved in relating land use to ground-water quality

Efforts to relate shallow ground-water quality to the land use near a well lead to several statistical difficulties. These include potential uncertainty in land-use categorical data due to misclassification, data closure, distributional skewing, and spatial autocorrelation. Methods of addressing these problems are, respectively, the establishment of limits on minimum buffer radius, the estimation of contrasts, rank-based tests of association, and sub-sampling to prevent buffer overlap. Relations between the presence of purgeable organic compounds in ground water and land use are used to illustrate these problems and methods.

Journal of the American Water Resources Associatio↗
USGS2014

Featured collection introduction: contaminants of emerging concern II

This collection of 13 articles focuses on CECs, and each of the articles highlights a specific aspect of this broad topic. The articles were solicited from researchers who participated in the second summer specialty conference on this topic, organized by the American Water Resources Association. The title of the conference was “CECs in Water Resources II: Research, Engineering and Community Action,” and the conference, as well as the articles in this featured collection, focus on a better and more comprehensive understanding of these contaminants. The conference was held in Denver, Colorado, on June 25-27, 2012, and approximately 125 conference attendees participated in an interdisciplinary forum of more than 75 presentations including keynote or plenary presentations by Dana Kolpin, Jorg Drewes, Heiko Schoenfuss, Chris Metcalfe, Vicki Blazer, and Tyrone Hayes. The first conference was held in 2007 and also produced a featured collection of articles (Battaglin and Kolpin, 2009).

Journal of the American Water Resources Associatio↗
USGS2013

Statistical evaluation of variables affecting occurrence of hydrocarbons in aquifers used for public supply, California

The variables affecting the occurrence of hydrocarbons in aquifers used for public supply in California were assessed based on statistical evaluation of three large statewide datasets; gasoline oxygenates also were analyzed for comparison with hydrocarbons. Benzene is the most frequently detected (1.7%) compound among 17 hydrocarbons analyzed at generally low concentrations (median detected concentration 0.024 μg/l) in groundwater used for public supply in California; methyl tert-butyl ether (MTBE) is the most frequently detected (5.8%) compound among seven oxygenates analyzed (median detected concentration 0.1 μg/l). At aquifer depths used for public supply, hydrocarbons and MTBE rarely co-occur and are generally related to different variables; in shallower groundwater, co-occurrence is more frequent and there are similar relations to the density or proximity of potential sources. Benzene concentrations are most strongly correlated with reducing conditions, regardless of groundwater age and depth. Multiple lines of evidence indicate that benzene and other hydrocarbons detected in old, deep, and/or brackish groundwater result from geogenic sources of oil and gas. However, in recently recharged (since ~1950), generally shallower groundwater, higher concentrations and detection frequencies of benzene and hydrocarbons were associated with a greater proportion of commercial land use surrounding the well, likely reflecting effects of anthropogenic sources, particularly in combination with reducing conditions.

California↗
USGS2014

Associations between water physicochemistry and Prymnesium parvum presence, abundance, and toxicity in west Texas reservoirs

Toxic blooms of golden alga ( Prymnesium parvum ) have caused substantial ecological and economic harm in freshwater and marine systems throughout the world. In North America, toxic blooms have impacted freshwater systems including large reservoirs. Management of water chemistry is one proposed option for golden alga control in these systems. The main objective of this study was to assess physicochemical characteristics of water that influence golden alga presence, abundance, and toxicity in the Upper Colorado River basin (UCR) in Texas. The UCR contains reservoirs that have experienced repeated blooms and other reservoirs where golden alga is present but has not been toxic. We quantified golden alga abundance (hemocytometer counts), ichthyotoxicity (bioassay), and water chemistry (surface grab samples) at three impacted reservoirs on the Colorado River; two reference reservoirs on the Concho River; and three sites at the confluence of these rivers. Sampling occurred monthly from January 2010 to July 2011. Impacted sites were characterized by higher specific conductance, calcium and magnesium hardness, and fluoride than reference and confluence sites. At impacted sites, golden alga abundance and toxicity were positively associated with salinity-related variables and blooms peaked at ~10&deg;C and generally did not occur above 20&deg;C. Overall, these findings suggest management of land and water use to reduce hardness or salinity could produce unfavorable conditions for golden alga.

Journal of the American Water Resources Associatio↗
USGS2014

Spatiotemporal associations of reservoir nutrient characteristics and the invasive, harmful alga Prymnesium parvum in West Texas

Golden alga ( Prymnesium parvum ) is a harmful alga that has caused ecological and economic harm in freshwater and marine systems worldwide. In inland systems of North America, toxic blooms have nearly eliminated fish populations in some systems. Modifying nutrient profiles through alterations to land or water use may be a viable alternative for golden alga control in reservoirs. The main objective of this study was to improve our understanding of the nutrient dynamics that influence golden alga bloom formation and toxicity in west Texas reservoirs. We examined eight sites in the Upper Colorado River basin, Texas: three impacted reservoirs that have experienced repeated golden alga blooms; two reference reservoirs where golden alga is present but nontoxic; and three confluence sites downstream of the impacted and reference sites. Total, inorganic, and organic nitrogen and phosphorus and their ratios were quantified monthly along with golden alga abundance and ichthyotoxicity between December 2010 and July 2011. Blooms persisted for several months at the impacted sites, which were characterized by high organic nitrogen and low inorganic nitrogen. At impacted sites, abundance was positively associated with inorganic phosphorus and bloom termination coincided with increases in inorganic nitrogen and decreases in inorganic phosphorus in late spring. Management of both inorganic and organic forms of nutrients may create conditions in reservoirs unfavorable to golden alga.

Journal of the American Water Resources Associatio↗
USGS2022

Water storage decisions and consumptive use may constrain ecosystem management under severe sustained drought

Drought has impacted the Colorado River basin for the past 20 years and is predicted to continue. In response, decisions about how much water should be stored in large reservoirs and how much water can be consumptively used will be necessary. These decisions have the potential to limit riverine ecosystem management options through the effect water-supply decisions have on reservoir elevations. We used projected hydrology and river temperatures to compare the outcome of combinations of water storage scenarios and consumptive use limits on metrics associated with ecosystem management of the Colorado River in Grand Canyon. Ecosystem management metrics included the ability to implement designer flows, temperature suitability for fishes, and fragmentation. We compared current water management operations to prioritizing storage in either Lake Mead or Lake Powell combined with three levels of consumptive use. Projected reservoir levels limited environmental flow delivery and increased fragmentation regardless of where water was stored if consumptive use was not limited. Warmer river temperatures associated with low reservoir levels are likely, creating suitable conditions for non-native species of concern, such as smallmouth bass. Water storage decisions provided variability and management flexibility, but water storage was less important when less water was available, highlighting the importance of keeping water in the system to provide flexibility for achieving ecosystem goals.

Arizona, Utah↗
USGS2026

Long-term monotonic trends in water budget components in the contiguous United States: Insights from two hydrologic models

Characterizing changes to water availability for domestic, industrial, agricultural, and other uses is essential to support water management. To better quantify these changes, the U.S. Geological Survey and National Science Foundation National Center for Atmospheric Research produced two hydrologic models simulating water budget components from 1980 to 2021 over the contiguous United States (CONUS). Both hydrologic models were driven by a common atmospheric forcing dataset and aggregated to common spatial and temporal scales, which enables a novel evaluation of congruency between the models. We present annual and seasonal trends in six water budget components (precipitation, evapotranspiration, streamflow, groundwater recharge, soil saturation, and snow water equivalent) based on the Mann–Kendall test for monotonic trend and Theil-Sen slope estimate for the water year 1983–2021 period for ~86,000 catchments in CONUS. Additional components and metrics from our analysis pipeline are available in an associated published dataset, which contains more than 46 million trend results. The water budget trends showed broad agreement with prior observational and modeling studies that indicate increasing trends in the northeast and decreasing trends in southwestern CONUS. We found the seasonal variability in water budget trends was greatest in the southern, central, and northwest CONUS. These findings support integrated trend assessments when coupled with trends in water quality and use.

Contiguous United States↗
USGS2017

A hydrologic drying bias in water-resource impact analyses of anthropogenic climate change

For water-resource planning, sensitivity of freshwater availability to anthropogenic climate change (ACC) often is analyzed with “offline” hydrologic models that use precipitation and potential evapotranspiration ( E p ) as inputs. Because E p is not a climate-model output, an intermediary model of E p must be introduced to connect the climate model to the hydrologic model. Several E p methods are used. The suitability of each can be assessed by noting a credible E p method for offline analyses should be able to reproduce climate models’ ACC-driven changes in actual evapotranspiration in regions and seasons of negligible water stress ( E w ). We quantified this ability for seven commonly used E p methods and for a simple proportionality with available energy (“energy-only” method). With the exception of the energy-only method, all methods tend to overestimate substantially the increase in E p associated with ACC. In an offline hydrologic model, the E p -change biases produce excessive increases in actual evapotranspiration ( E ), whether the system experiences water stress or not, and thence strong negative biases in runoff change, as compared to hydrologic fluxes in the driving climate models. The runoff biases are comparable in magnitude to the ACC-induced runoff changes themselves. These results suggest future hydrologic drying (wetting) trends likely are being systematically and substantially overestimated (underestimated) in many water-resource impact analyses.

Journal of the American Water Resources Associatio↗
USGS2011

Digital hydrologic networks supporting applications related to spatially referenced regression modeling

Digital hydrologic networks depicting surface-water pathways and their associated drainage catchments provide a key component to hydrologic analysis and modeling. Collectively, they form common spatial units that can be used to frame the descriptions of aquatic and watershed processes. In addition, they provide the ability to simulate and route the movement of water and associated constituents throughout the landscape. Digital hydrologic networks have evolved from derivatives of mapping products to detailed, interconnected, spatially referenced networks of water pathways, drainage areas, and stream and watershed characteristics. These properties are important because they enhance the ability to spatially evaluate factors that affect the sources and transport of water-quality constituents at various scales. SPAtially Referenced Regressions On Watershed attributes (SPARROW), a process-based &frasl; statistical model, relies on a digital hydrologic network in order to establish relations between quantities of monitored contaminant flux, contaminant sources, and the associated physical characteristics affecting contaminant transport. Digital hydrologic networks modified from the River Reach File (RF1) and National Hydrography Dataset (NHD) geospatial datasets provided frameworks for SPARROW in six regions of the conterminous United States. In addition, characteristics of the modified RF1 were used to update estimates of mean-annual streamflow. This produced more current flow estimates for use in SPARROW modeling.

Journal of the American Water Resources Associatio↗
USGS2012

Changes in shallow groundwater quality beneath recently urbanized areas in the Memphis, Tennessee area

Memphis, the largest city in the state of Tennessee, and its surrounding suburbs depend on a confined aquifer, the Memphis aquifer, for drinking water. Concern over the potential for downward movement of water from an overlying shallow aquifer to the underlying Memphis aquifer provided impetus for monitoring groundwater quality within the shallow aquifer. The occurrence of volatile organic compounds (VOCs), nitrate, and pesticides in samples from the shallow well network indicate a widespread affect on water quality from the overlying urban land use. Total pesticide concentration was generally higher in more recently recharged groundwater indicating that as the proportion of recent water increases, the occurrence of pesticides related to the current urban land use also increases. Groundwater samples with nitrate concentrations greater than 1.5 mg/l and detectable concentrations of the pesticides atrazine and simazine also had higher concentrations of chloroform, a VOC primarily associated with urban land use, than in other samples. The age of the water from these wells indicates that these concentrations are most likely not representative of past agricultural use, but of more recent urban use of these chemicals. Given that the median age of water represented by the shallow well network was 21 years, a lag time likely exists between changes in land use and the occurrence of constituents related to urbanization in shallow groundwater.

Journal of the American Water Resources Associatio↗
USGS2007

Hydrogeology and paths of flow in the carbonate bedrock aquifer, northwestern Indiana

The U.S. Geological Survey (USGS) is assessing the ground.water resources of the carbonate bedrock aquifers in Indiana and Ohio as part of their Regional Aquifer Systems Analysis program. Part of this assessment includes the determination of unknown aspects of the hydraulic characteristics, boundaries, and flow paths of the carbonate aquifer. To accomplish this, the USGS drilled three wells through the carbonate aquifer near the Kankakee River in northwestern Indiana. Geophysical logs were used to help determine depths and thicknesses for testing and to help describe geology at the three wells. Packer tests were used to determine direction of ground-water flow and to provide data for an analysis of the distribution of transmissivity in the carbonate aquifer. Transmissivity of the carbonates is associated with two physical characteristics of the rocks: fractures and interconnected porosity. Almost all of the transmissivity is derived from horizontal fracturing; however, only a few of the fractures present in the carbonate are transmissive. Some transmissivity is associated with a zone of fossiliferous, vuggy dolomite, which yields water from the rock matrix. Most of the transmissivity is associated with large fractures and solution crevices in the upper 30 feet of the bedrock; less transmissivity is associated with the deeper vuggy reef material, even where extensively fractured. Transmissivity of individual fractures and fossiliferous zones ranges from 300 to 27,000 feet squared per day. The aquifer bottom is defined by a lack of transmissive fractures and an increased shale content near the contact of the Silurian and Ordovician sections. Water-level data from the three wells indicate that flow is horizontal at well site 1 north of the Kankakee River, upward at well site 2 near the river, and downward at well site 3 south of the river. Most of the flow occurs in the upper part of the carbonate bedrock where fracturing and solution-enlarged crevices are most developed. Water levels indicate the the Kankakee River is a hydrologic boundary for the regional carbonate bedrock aquifer.

Indiana↗
USGS2026

Low streamflows in Massachusetts: Variability over space and time and relations with climatic and basin variables

Streamflows in Massachusetts have set record lows in recent years despite generally wetter conditions than during the drought of the 1960s, and the reasons for this are not known. To analyse potential drivers of low streamflows in Massachusetts, six low-flow metrics were computed at 107 streamgages. These metrics represent low-flow magnitude, magnitude normalized to median flows, and duration. Multiple linear regressions were used to analyse the variability of low flows over space and time. Potential explanatory variables were computed using climatic, land use, water use, and basin data. For all low-flow metrics, the ratio of precipitation to potential evapotranspiration (P/PET) in July–August explained the most variability, with decreasing P/PET largely explained by lower precipitation. Water/wetland area was a significant explanatory variable in all the normalized-magnitude and duration models, with greater area associated with lower normalized magnitudes and with shorter durations of low flows. Human influence (characterized by development, population, water use, and artificial water storage) had mixed effects. Trends from 1983 to 2022 in summer P/PET and human influence have been strongest in the eastern part of the state where the strongest decreases in flows are observed. Low flows in Massachusetts seem to be driven by a combination of low summer precipitation and human effects, though the specific mechanisms of human influence on flow likely vary between basins.

Massachusetts↗