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At least 739 records · Page 41Linked to original sources
USGS1977

Preliminary evaluation of flood frequency relations in the urban areas of Memphis, Tennessee

A storm-runoff relation for streams in the urban areas of Memphis was determined by a statistical evaluation of 59 flood discharges from 19 gaging stations. These flood discharges were related to drainage area, percent imperviousness of the drainage basin, and rainfall occurring over 120-minute periods. The defined relation is Q = (158.3A^(0.777A^(-0.02)))*((IMP+1)^(0.227))*((I120)^((0.539*(I120))^0.40)) where Q is flood discharge in cfs, A is drainage area in square miles, IMP is percent imperviousness in the basin, and 1120 is rainfall in inches, over 120 minute time period. The defined relation was used to synthesize sets of annual flood peaks for drainage basins ranging from .05 square miles to 10 square miles and imperviousness ranging from 0 to 80 percent for the period of rainfall record at Memphis. From these series of flood peaks, frequency relations were defined and presented for 2, 5, 10, 25, 50 and 100 year recurrent intervals.

Tennessee↗
USGS1995

Subsurface recharge to the Tesuque aquifer system from selected drainage basins along the western side of the Sangre de Cristo Mountains near Santa Fe, New Mexico

Water budgets developed for basins of five streams draining the western side of the Sangre de Cristo Mountains in northern New Mexico indicate that subsurface inflow along the mountain front is recharging the Tesuque aquifer system of the Espanola Basin. Approximately 14,700 acre-feet of water per year, or 12.7 percent of average annual precipitation over the mountains, is calculated to leave the mountain block and enter the basin as subsurface recharge from the drainage basins of the Rio Nambe, Rio en Medio, Tesuque Creek, Little Tesuque Creek, and Santa Fe River. About 5,520 acre- feet per year, or about 12 percent of average annual precipitation, is calculated to enter from the Rio Nambe drainage basin; about 1,710 acre- feet per year, or about 15 percent of average annual precipitation, is calculated to enter from the Rio en Medio drainage basin; about 1,530 acre- feet, or about 10 percent of average annual precipi- tation, is calculated to enter from the Tesuque Creek drainage basin; about 1,790 acre-feet, or about 19 percent of average annual precipitation, is calculated to enter from the Little Tesuque Creek drainage basin; and about 4,170 acre-feet per year, or about 12 percent average annual precipitation, is calculated to enter from the Santa Fe River drainage basin. Calculated subsurface recharge values were used to define maximum fluxes permitted along the specified-flux boundary defining the mountain front of the Sangre De Cristo Mountains in a numerical computer model of the Tesuque aquifer system near Santa Fe, New Mexico.

Water-Resources Investigations Report↗
USGS2001

Use of a precipitation-runoff model to simulate natural streamflow conditions in the Methow River basin, Washington

Management of the water resources of the Methow River Basin is changing in response to the listing of three species of fish under the Endangered Species Act and the Washington State-legislated watershed-planning process. Management options must be considered that minimize adverse effects on people but meet instream flow needs for fish. This report describes the construction and calibration of the Methow River Basin watershed model and evaluates the accuracy of the model as a predictive tool for assessing the natural instream flow conditions. The term ?natural? instream flow is stressed because surface water within the Basin is used for agricultural irrigation through an extensive system of diversions. The USGS Modular Modeling System was used for the watershed modeling component of the Methow River Basin study. The Geographic Information System Weasel characterized the physical properties of the basin, and the Precipitation-Runoff Modeling System simulated the natural streamflow. Natural streamflow conditions in the Basin were difficult to calibrate because six of the seven streamflow gaging stations are located below irrigation diversions and few streamflow measurements exist for the study area before the diversions were present. Therefore, limited records of natural streamflow conditions were available and estimations concerning some physical processes could not be quantified. Streamflow was simulated for water years 1992-99 to calibrate the model to measured streamflows. Simulated and measured streamflow generally showed close agreement, especially during spring runoff from snowmelt. Low-flow periods, most restrictive to fish habitation, were simulated reasonably well, yet possessed the most uncertainty. Simulations of the total annual runoff as a percentage of measured annual runoff for the 8-year calibration period at seven gaging stations ranged from -33.7 to +30.5 percent with 70 percent of the simulated values within 16 percent. Simulation of water years 1959-99 demonstrated great variability in monthly streamflow statistics. The simulated mean monthly flows for the seven streamflow-gaging stations were an average of 11.5 percent higher for the calibration period (1992-99) than for the entire simulation period (1959-99).

Water-Resources Investigations Report↗
USGS2003

Water-quality trend analysis and sampling design for streams in North Dakota, 1971-2000

This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the North Dakota Department of Health, to analyze historical water-quality trends in selected dissolved major ions, nutrients, and dissolved trace metals for 10 streams in southwestern and eastern North Dakota and to develop an efficient sampling design to monitor future water-quality trends. A time-series model for daily streamflow and constituent concentration was used to identify significant concentration trends, separate natural hydroclimatic variability in concentration from variability that could have resulted from anthropogenic causes, and evaluate various sampling designs to monitor future water-quality trends. The interannual variability in concentration as a result of variability in streamflow, referred to as the annual concentration anomaly, generally was high for all constituents and streams used in the trend analysis and was particularly sensitive to the severe drought that occurred in the late 1980's and the very wet period that began in 1993 and has persisted to the present (2002). Although climatic conditions were similar across North Dakota during the trend-analysis period (1971-2000), significant differences occurred in the annual concentration anomalies from constituent to constituent and location to location, especially during the drought and the wet period. Numerous trends were detected in the historical constituent concentrations after the annual concentration anomalies were removed. The trends within each of the constituent groups (major ions, nutrients, and trace metals) showed general agreement among the streams. For most locations, the largest dissolved major-ion concentrations occurred during the late 1970's and concentrations in the mid- to late 1990's were smaller than concentrations during the late 1970's. However, the largest concentrations for three of the Missouri River tributaries and one of the Red River of the North tributaries occurred during the mid- to late 1990's. Concentration trends for total ammonia plus organic nitrogen showed close agreement among the streams for which that constituent was evaluated. The largest concentrations occurred during the early 1980's, and the smallest concentrations occurred during the early 1990's. Nutrient data were not available for the early 1970's or late 1990's. Although a detailed analysis of the causes of the trends was beyond the scope of this report, a preliminary analysis of cropland, livestock-inventory, and oil-production data for 1971-2000 indicated the concentration trends may be related to the livestock-inventory and oil-production activities in the basins. Dissolved iron and manganese concentrations for the southwestern North Dakota streams generally remained stable during 1971-2000. However, many of the recorded concentrations for those streams were less than the detection limit, and trends that were masked by censoring may have occurred. Several significant trends were detected in dissolved iron and manganese concentrations for the eastern North Dakota streams. Concentrations for those streams either remained stable or increased during most of the 1970's and then decreased rapidly for about 2 years beginning in the late 1970's. The concentrations were relatively stable from the early 1980's to 2000 except at two locations where dissolved iron concentrations increased during the early 1990's. The most efficient overall sampling designs for the detection of annual trends (that is, trends that occur uniformly during the entire year) consisted of balanced designs in which the sampling dates and the number of samples collected remained fixed from year to year and in which the samples were collected throughout the year rather than in a short timespan. The best overall design for the detection of annual trends consisted of three samples per year, with samples collected near the beginning of December, April, and August. That design had acceptable sensitivity for the detection of trends in most constituents at all locations. Little improvement in sensitivity was achieved by collecting more than three samples per year. The sampling designs that were first evaluated for annual trends also were evaluated with regard to their sensitivity to detect seasonal trends that occurred during three seasons--April through August, August through December, and December through April. Design results indicated that an average of one extra sample per station per year resulted in an efficient design for detecting seasonal trends. However, allocation of the extra samples varied depending on the station, month, and constituent group (major ions, nutrients, and trace metals).

North Dakota↗
USGS1998

Regional rainfall-runoff relations for simulation of streamflow for watersheds in Du Page County, Illinois

Rainfall and streamflow data collected from July 1986 through September 1993 were utilized to calibrate and verify a continuous-simulation rainfall-runoff model for three watersheds (11.8--18.0 square miles in area) in Du Page County. Classification of land cover into three categories of pervious (grassland, forest/wetland, and agricultural land) and one category of impervious subareas was sufficient to accurately simulate the rainfall-runoff relations for the three watersheds. Regional parameter sets were obtained by calibrating jointly all parameters except fraction of ground-water inflow that goes to inactive ground water (DEEPFR), interflow recession constant (IRC), and infiltration (INFILT) for runoff from all three watersheds. DEEPFR and IRC varied among the watersheds because of physical differences among the watersheds. Two values of INFILT were obtained: one representing the rainfall-runoff process on the silty and clayey soils on the uplands and lake plains that characterize Sawmill Creek, St. Joseph Creek, and eastern Du Page County; and one representing the rainfall-runoff process on the silty soils on uplands that characterize Kress Creek and parts of western Du Page County. Regional rainfall-runoff relations, defined through joint calibration of the rainfall-runoff model and verified for independent periods, presented in this report, allow estimation of runoff for watersheds in Du Page County with an error in the total water balance less than 4.0 percent; an average absolute error in the annual-flow estimates of 17.1 percent with the error rarely exceeding 25 percent for annual flows; and correlation coefficients and coefficients of model-fit efficiency for monthly flows of at least 87 and 76 percent, respectively. Close reproduction of the runoff-volume duration curves was obtained. A frequency analysis of storm-runoff volume indicates a tendency of the model to undersimulate large storms, which may result from underestimation of the amount of impervious land cover in the watershed and errors in measuring rainfall for convective storms. Overall, the results of regional calibration and verification of the rainfall-runoff model indicate the simulated rainfall-runoff relations are adequate for stormwater-management planning and design for watersheds in Du Page County.

Water-Resources Investigations Report↗
USGS2026

Water use permits as of July 2024 and reported water use near the North Unit of Theodore Roosevelt National Park, North Dakota, 1980–2023

Starting in the early 2000s, increasing oil and gas development in western North Dakota created a need for additional water resources from surface-water and groundwater sources near the North Unit of Theodore Roosevelt National Park. To summarize the use of water in that area, the U.S. Geological Survey, in cooperation with the National Park Service, developed a map of surface-water and groundwater resources, aquifers, and water-use diversions, and plotted water-use trends from 1980 to 2023. Reported water used from permits in the map area has more than doubled since 2020, increasing from about 750 acre-feet in 2020 to about 2,300 acre-feet in 2022 and 2,000 acre-feet in 2023. Surface water provided the primary source of reported water used for the study period with an average of about 410 acre-feet per year from 1980 through 2017 and about 1,330 acre-feet per year from 2018 through 2023. After 2011, groundwater sourced from the Little Missouri River, Tobacco Garden Creek, Fox Hills, Fort Union, and Dakota aquifers became a larger portion of total annual reported water use from permits in the map area. From 1980 through 2015, water use for irrigation averaged 86 percent of the total annual reported surface-water and groundwater use in the map area. Starting in 2011, however, industrial uses became a proportionally larger total use of water, and in 2015, became the highest reported volume of water use in the map area. From 2011 to 2023, industrial use designated for water depots increased from 50 acre-feet to about 1,370 acre-feet, accounting for about 70 percent of total reported water use in the map area in 2023.

North Dakota↗
USGS2005

Occurrence of organic wastewater compounds in wastewater effluent and the Big Sioux River in the Upper Big Sioux River basin, South Dakota, 2003-2004

The U.S. Geological Survey (USGS) in cooperation with the East Dakota Water Development District conducted a reconnaissance study to determine the occurrence of organic wastewater compounds (OWCs) in wastewater effluent and the Big Sioux River at or near the cities of Watertown, Volga, and Brookings in the upper Big Sioux River Basin during August 2003 through June 2004. For each city, samples were collected from the wastewater treatment plant (WWTP) effluent and from Big Sioux River sites upstream and downstream from where the wastewater effluent discharges to the Big Sioux River. For Watertown and Brookings, samples were collected during a low-flow period (August 2003) and a runoff period (June 2004). For Volga, samples were collected during two low-flow periods (August 2003 and October 2003) and a runoff period (June 2004). A total of 125 different OWCs were analyzed for and were classified into six compound classes-human pharmaceutical compounds (HPCs), human and veterinary antibiotic compounds (HVACs), major agricultural herbicides (MAHs), household, industrial, and minor agricultural compounds (HIACs), polyaromatic hydrocarbons (PAHs), and sterol compounds (SCs). Of the 125 different OWCs, 45 had acceptable analytical method performance, were detected at concentrations greater than the study reporting levels, and were included in analyses and discussion related to occurrence of OWCs in wastewater effluents and the Big Sioux River. OWCs in all six compound classes were detected in water samples from sampling sites in the Watertown area. The Watertown WWTP discharged continuously to the Big Sioux River during both the low-flow August 2003 and runoff June 2004 sampling periods. Total OWC concentrations for Big Sioux River sites upstream from the Watertown WWTP discharge generally were small, less than 6 micrograms per liter (µg/L) for both sampling periods. SCs accounted for nearly all of the total OWC concentrations for upstream Big Sioux River sites for the low-flow August 2003 sampling period, and MAHs accounted for nearly all of the total OWC concentrations for the runoff June 2004 sampling period. Total OWC concentrations for samples collected from the Watertown wastewater effluent were relatively large for both sampling periods (estimated concentrations ranged from 20 to 41 µg/L), and primarily consisted of HIACs, SCs, and HVACs. Total OWC concentrations for Big Sioux River sites downstream from the Watertown WWTP discharge were relatively large for the low-flow August 2003 sampling period (estimated concentrations ranged from 6.9 to 19 µg/L) and smaller for the runoff June 2004 sampling period (estimated concentrations ranged from 3.3 to 6.5 µg/L), a pattern that probably reflects a greater fraction of the total flow of the Big Sioux River being derived from WWTP discharge during the low-flow sampling period. Major OWC classes contributing to total OWC concentrations for Big Sioux River sites downstream from the Watertown WWTP were HIACs, SCs, and HVACs. Total OWC concentrations decreased substantially between the two downstream Big Sioux River sites. Although confident conclusions could not be made primarily due to possible effects of non-Lagrangian sampling, OWC results for the Watertown area might indicate that (1) OWCs for upstream Big Sioux River sites probably were primarily contributed by nonpoint agricultural sources, with livestock agriculture accounting for most of the total OWC concentration for the low-flow August 2003 sampling period, and crop agriculture accounting for most of the total OWC concentration for the runoff June 2004 sampling period; (2) OWCs for downstream Big Sioux River sites were substantially influenced by contributions from the Watertown WWTP during both the low-flow and runoff sampling periods; and (3) contributions of OWCs that might be derived from nonpoint livestock agricultural sources increased in proportion for the most downstream site for both the low-flow and runoff sampling periods. Suspected endocrine-disrupting compounds (EDCs) were detected in all Big Sioux River samples in the Watertown area. For both the low-flow and runoff sampling periods, the numbers of EDCs detected, and EDC concentrations and loads generally were larger for downstream Big Sioux River sites than for upstream Big Sioux River sites. Combined EDC concentrations for downstream Big Sioux River sites consisted mostly of HIACs for the low-flow sampling period and both HIACs and MAHs for the runoff sampling period. OWCs in all compound classes except PAHs were detected in samples from sites in the Volga area. The Volga WWTP was not discharging to the Big Sioux River during the low-flow August 2003 and runoff June 2004 sampling periods, but was discharging continuously to the Big Sioux River during the low-flow October 2003 sampling period. For the low-flow August 2003 sampling period, the upstream Big Sioux River site had larger total OWC concentrations and loads than downstream Big Sioux River sites, and SCs accounted for most of the total OWC concentration for all Big Sioux River sites. For the low-flow October 2003 sampling period, when the Volga WWTP was discharging to the Big Sioux River, total OWC concentrations and loads were larger for the downstream Big Sioux River site than for the upstream site, and the increase in load corresponded well with the load contributed by the Volga wastewater effluent discharge, especially for HIACs. HIACs and SCs accounted for most of the total OWC concentrations for Big Sioux River sites for the October 2003 sampling period. For the June 2004 runoff sampling period, the upstream Big Sioux River site had smaller total OWC concentrations and loads than downstream Big Sioux River sites, and MAHs accounted for most of the total OWC concentrations for all Big Sioux River sites. Although confident conclusions could not be made due to possible effects of non-Lagrangian sampling, the data might indicate that (1) for the low-flow August 2003 sampling period, nonpoint livestock agricultural and/or human wastewater sources might have been the primary contributors to occurrence of OWCs at Big Sioux River sampling sites; (2) for the low-flow October 2003 sampling period, nonpoint livestock sources and upstream human wastewater sources primarily contributed to occurrence of OWCs at Big Sioux River sampling sites; (3) for the runoff June 2004 sampling period, nonpoint crop agricultural sources primarily contributed to occurrence of OWCs at Big Sioux River sampling sites; (4) for the low-flow August 2003 and runoff June 2004 sampling periods, seepage of water from the Volga WWTP had little effect on downstream OWC concentrations; and (5) for the low-flow October 2003 sampling period, the Volga wastewater effluent discharge contributed to downstream OWC concentrations. EDCs were detected in all samples collected from sampling sites in the Volga area. For all sampling periods, total EDC concentrations generally were similar between upstream and downstream Big Sioux River sites and consisted of HIACs and MAHs. HIACs accounted for most of the total EDC concentrations for the low-flow August 2003 and October 2003 sampling periods, and MAHs accounted for most of the total EDC concentrations for the runoff June 2004 sampling period for all Big Sioux River sites. OWCs in all compound classes except PAHs were detected in water samples from sampling sites in the Brookings area. The Brookings WWTP discharged continuously to the Big Sioux River during all sampling periods. For the low-flow August 2003 sampling period, the upstream site had slightly smaller total OWC concentrations and loads compared to the downstream Big Sioux River sites. SCs and HIACs accounted for most of the total OWC concentration in all Big Sioux River sampling sites, but the proportion of SCs increased at the most downstream site. For the runoff June 2004 sampling period, the upstream site generally had smaller total OWC concentrations and loads than downstream Big Sioux River sites. MAHs accounted for most of the total OWC concentration for all Big Sioux River sites, but the proportion of SCs increased at the most downstream site. Although confident conclusions could not be made due to possible effects of non-Lagrangian sampling, the data might indicate that (1) for the low-flow August 2003 sampling period, nonpoint livestock agricultural sources probably primarily contributed to occurrence of OWCs at all Big Sioux River sampling sites, and the Brookings WWTP wastewater effluent discharge contributed but did not have a substantial effect on concentrations at downstream sites; and (2) for the runoff June 2004 sampling period, nonpoint crop agricultural sources primarily contributed to occurrence of OWCs at all Big Sioux River sites, contributions of OWCs that might be derived from nonpoint livestock agricultural sources increased in proportion to other sources for the most downstream site, and the Brookings WWTP wastewater effluent discharge probably did not substantially contribute to total OWC concentrations at downstream sampling sites. EDCs were detected in all samples collected from sampling sites in the Brookings area. Total EDC concentrations for the upstream site consisted entirely of MAHs. Total EDC concentrations for downstream sites consisted of MAHs and HIACs. HIACs accounted for most of the total EDC concentrations for the low-flow August 2003 sampling period, and MAHs accounted for most of the total EDC concentrations for the runoff June 2004 sampling period for downstream Big Sioux River sites. The city of Watertown is located near the upstream part of the Big Sioux River Basin, where the mean annual flow of the Big Sioux River is less than 100 cubic feet per second (ft 3 /s). Watertown WWTP discharges can account for a substantial part of the flow in the Big Sioux River, especially during low-flow periods. Effects of the Watertown WWTP wastewater effluent discharges on the occurrence of OWCs in the Big Sioux River downstream were apparent during both the low-flow and runoff sampling periods. For Volga and Brookings, which are farther downstream and where the mean annual flow of the Big Sioux River exceeds 400 ft 3 /s, wastewater effluent discharges from the Volga and Brookings WWTPs probably influenced the occurrence of OWCs in the Big Sioux River, but probably did not substantially contribute to total OWC concentrations, especially during the runoff sampling period.

South Dakota↗
USGS2004

Estimating the magnitude of bankfull flows for streams in Idaho

Methods for estimating magnitudes of peak flows with recurrence intervals of 1.5 and 2.33 years were developed for ungaged sites on streams throughout Idaho. These peak flows represent the magnitudes at and near bankfull stage and are needed for quantification of water rights required to maintain or restore fish and wildlife habitats and riparian vegetation. Data from a previous report detailing methods for estimating magnitudes with recurrence intervals of 2 to 500 years were used in this study. Generalized least-squares regression techniques were used to calculate the final coefficients and measures of accuracy for the regression equations for each of nine regions. The equations relate basin and climatic characteristics to peak flows with recurrence intervals of 1.5 and 2.33 years. The basin and climatic characteristics used to develop the equations included drainage area, mean basin elevation, forested area, mean annual precipitation, basin slope, north-facing slopes greater than 30 percent, and slopes greater than 30 percent. Average standard errors of the regression model ranged from +150 to -60.1 percent, and average standard errors of prediction ranged from +165 to -62.2 percent. The range of prediction errors was narrowest, -48.9 to -32.9 percent, for region 5. A computer program was developed to automate the calculations required for the regional regression calculations. Results from this program comprised calculated peak flows, site-specific standard errors of prediction, and the 90-percent confidence intervals for the estimates.

Idaho;Montana;Nevada;Oregon;Washington;Wyoming↗
USGS2015

Spatiotemporal variation of surface shortwave forcing from fire-induced albedo change in interior Alaska

The albedo change caused by both fires and subsequent succession is spatially heterogeneous, leading to the need to assess the spatiotemporal variation of surface shortwave forcing (SSF) as a component to quantify the climate impacts of high-latitude fires. We used an image reconstruction approach to compare postfire albedo with the albedo assuming fires had not occurred. Combining the fire-caused albedo change from the 2001-2010 fires in interior Alaska and the monthly surface incoming solar radiation, we examined the spatiotemporal variation of SSF in the early successional stage of around 10 years. Our results showed that while postfire albedo generally increased in fall, winter, and spring, some burned areas could show an albedo decrease during these seasons. In summer, the albedo increased for several years and then declined again. The spring SSF distribution did not show a latitudinal decrease from south to north as previously reported. The results also indicated that although the SSF is usually largely negative in the early successional years, it may not be significant during the first postfire year. The annual 2005-2010 SSF for the 2004 fire scars was -1.30, -4.40, -3.31, -4.00, -3.42, and -2.47 Wm-2. The integrated annual SSF map showed significant spatial variation with a mean of -3.15 Wm-2 and a standard deviation of 3.26 Wm-2, 16% of burned areas having positive SSF. Our results suggest that boreal deciduous fires would be less positive for climate change than boreal evergreen fires. Future research is needed to comprehensively investigate the spatiotemporal radiative and non-radiative forcings to determine the effect of boreal fires on climate.

Alaska↗
USGS1968

Developing a state water plan: Ground-water conditions in Utah, spring of 1968

This report is the fifth in a series of annual reports that describe ground-water conditions in Utah. Reports in this series are prepared cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources and are designed to provide data to enable interested parties such as legislators, administrators, and planners to keep abreast of changing ground-water conditions. This report, like the others (see references, p. 105), contains information on well construction, ground-water withdrawals, water-level changes, and related changes in precipitation and streamflow. It also contains supplementary data that are related to ground-water use in some areas. In reports of this series, the inclusion of such supplementary data as graphs showing chemical quality of water and maps showing water-table configuration is intended only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions. The report includes individual discussions of the most important areas of ground-water withdrawal in the State for the calendar year 1967. Water-level fluctuations, however, are described for the period spring 1967 to spring 1968. Included for the first time in this series of annual reports is a (1) summation of the withdrawal of water from wells in the 5 years 1963-67 (table 3) and (2) maps and discussions of water-level changes for the 5-year period 1963-68. Many of the data used in the report were collected by the Geological Survey in cooperation with the Division of Water Rights, Utah Department of Natural Resources.

Utah↗
USGS2016

External quality assurance project report for the National Atmospheric Deposition Program’s National Trends Network and Mercury Deposition Network, 2013–14

The U.S. Geological Survey Branch of Quality Systems operated five distinct programs to provide external quality assurance monitoring for the National Atmospheric Deposition Program’s (NADP) National Trends Network and Mercury Deposition Network during 2013–14. The National Trends Network programs include (1) a field audit program to evaluate sample contamination and stability, (2) an interlaboratory comparison program to evaluate analytical laboratory performance, and (3) a colocated sampler program to evaluate bias from precipitation sampler upgrades. The Mercury Deposition Network programs include the (4) system blank program and (5) an interlaboratory comparison program. The results indicate that NADP data continue to be of sufficient quality for the analysis of spatial distributions and time trends for chemical constituents in wet deposition. The field audit program results indicate that sample contamination levels for calcium, nitrate, and sulfate continued to increase during the study period while sodium and chloride contamination decreased and magnesium, potassium, ammonium, and hydrogen-ion contamination have remained relatively constant. Analyte losses due to potential sample instability were negligible. The NADP Central Analytical Laboratory produced interlaboratory comparison results with low bias and variability compared to other domestic and international laboratories that support atmospheric deposition monitoring. Colocated sampler program results from dissimilar colocated collectors suggest that the retrofit of the National Trends Network with N-CON Systems precipitation collectors could cause shifts in NADP annual deposition (concentration multiplied by depth) values from +6.2 to +51 percent for ammonium, from +8.1 to +61 percent for nitrate, from 3.8 to 71 percent for sulfate, from –24 to +15 percent for hydrogenion deposition, and larger shifts (from –14 to +102 percent) for calcium, magnesium, sodium, potassium, and chloride. The N-CON Systems collector typically catches more precipitation than the NADP-approved Aerochem Metrics Model 301 collector, but it typically caught slightly less precipitation than the Aerochem Metrics collector at a wind-swept, high-altitude site during water year 2013. Paired, identical OTT Pluvio-2 and ETI Noah IV rain gages were operated at the same sites. Results of the colocated rain gages indicate from 0 to 3.7 percent median absolute percent difference for weekly precipitation-depth measurements and from 0.05 to 5.6 absolute percent difference for annual total precipitation depth. The Mercury Deposition Network programs include the system blank program and an interlaboratory comparison program. System blank results indicated that maximum total mercury contamination concentrations in samples were less than the third percentile of all Mercury Deposition Network sample concentrations. The Mercury Analytical Laboratory produced chemical concentration results with low bias and variability compared with other domestic and international laboratories that support atmospheric-deposition monitoring.

Scientific Investigations Report↗
USGS2006

Status of water levels and selected water-quality conditions in the Sparta-Memphis aquifer in Arkansas, Spring-Summer 2003

During the spring of 2003, water levels were measured in 341 wells in the Sparta-Memphis aquifer in Arkansas. Waterquality samples were collected for temperature and specificconductance measurements during the spring-summer of 2003 from 70 wells in Arkansas in the Sparta-Memphis aquifer. Maps of areal distribution of potentiometric surface, change in waterlevel measurements from 1999 to 2003, and specific-conductance data reveal spatial trends across the study area. The highest water-level altitude measured in Arkansas was 328 feet above National Geodetic Vertical Datum of 1929 (NGVD of 1929) in Craighead County; the lowest water-level altitude was 199 feet below NGVD of 1929 in Union County. Three large cones of depression are shown in the 2003 potentiometric surface map, centered in Columbia, Jefferson, and Union Counties in Arkansas as a result of large withdrawals for industrial and public supplies. A broad depression exists in western Poinsett County in Arkansas. The potentiometric surface indicates that large withdrawals have altered or reversed the natural direction of flow in most areas. In the northern third of the study area the flow is from the east, west, and north towards the broad depression in Poinsett County. In the central third of the study area the flow is dominated by the cone of depression centered in Jefferson County. In the southern third of the study area the flow is dominated by the two cones of depression in Union and Columbia Counties. A map of water-level changes from 1999 to 2003 was constructed using water-level measurements from 281 wells. The largest rise in water level measured was about 57.8 feet in Columbia County. The largest decline in water level measured was about -71.6 feet in Columbia County. Areas with a general rise are shown in Arkansas, Bradley, Calhoun, Cleveland, Columbia, Ouachita, and Union Counties. Areas with a general decline are shown in Craighead, Crittenden, Cross, Desha, Drew, Jefferson, Lonoke, Phillips, Poinsett, Prairie, and Woodruff Counties. Hydrographs were constructed for wells with a minimum of 25 years of water-level measurements. A trend line using a linear regression was calculated for the period of record from spring of 1978 to spring of 2003 to determine the annual decline or rise in feet per year for water levels in each well. The hydrographs were grouped by county. The mean values for county annual water-level decline or rise ranged from -1.42 to 0.27 foot per year. Specific conductance ranged from 82 microsiemens per centimeter at 25 degrees Celsius in Jefferson County to about 1,210 microsiemens per centimeter at 25 degrees Celsius in Lee County. The mean specific conductance was 400 microsiemens per centimeter at 25 degrees Celsius.

Scientific Investigations Report↗
USGS2007

Concentrations and Loads of Organic Compounds and Trace Elements in Tributaries to Newark and Raritan Bays, New Jersey

A study was undertaken to determine the concentrations and loads of sediment and chemicals delivered to Newark and Raritan Bays by five major tributaries: the Raritan, Passaic, Rahway, Elizabeth, and Hackensack Rivers. This study was initiated by the State of New Jersey as Study I-C of the New Jersey Toxics Reduction Workplan for the New York-New Jersey Harbor, working under the NY-NJ Harbor Estuary Program (HEP) Contaminant Assessment and Reduction Program (CARP). The CARP is a comprehensive effort to evaluate the levels and sources of toxic contaminants to the tributaries and estuarine areas of the NY-NJ Harbor, including Newark and Raritan Bays. The Raritan and Passaic Rivers are large rivers (mean daily discharges of 1,189 and 1,132 cubic feet per second (ft3/s), respectively), that drain large, mixed rural/urban basins. The Elizabeth and Rahway Rivers are small rivers (mean daily discharges of 25.9 and 49.1 ft3/s, respectively) that drain small, highly urbanized and industrialized basins. The Hackensack River drains a small, mixed rural/urban basin, and its flow is highly controlled by an upstream reservoir (mean daily discharge of 90.4 ft3/s). These rivers flow into urbanized estuaries and ultimately, to the Atlantic Ocean. Each of these tributaries were sampled during two to four storm events, and twice each during low-flow discharge conditions. Samples were collected using automated equipment installed at stations adjacent to U.S. Geological Survey streamflow-gaging stations near the heads-of-tide of these rivers. Large-volume (greater than 50 liters of water and a target of 1 gram of sediment), flow-weighted composite samples were collected for chemical analysis using filtration to collect suspended particulates and exchange resin (XAD-2) to sequester dissolved contaminants. Composite whole-water samples were collected for dissolved polycyclic aromatic hydrocarbons (PAH) and for trace element analysis. Additional discrete grab samples were collected throughout each event for trace-element analysis, and multiple samples were collected for suspended sediment (SS), particulate carbon (POC), and dissolved organic carbon (DOC) analysis. The suspended sediment and exchange resin were analyzed for 114 polychlorinated biphenyls (PCBs, by US EPA method 1668A, modified), seven 2,3,7,8-substituted chlorinated dibenzo-p-dioxins (CDD) and 10 dibenzo-p-difurans (CDF) (by US EPA method 1613), 24 PAHs (by low-resolution isotope dilution/mass-spectral methods), 27 organo-chlorine pesticides (OCPs) (by high resolution isotope dilution/mass-spectral methods), and the trace elements mercury (Hg), methyl-mercury (MeHg), lead (Pb), and cadmium (Cd). Isotope dilution methods using gas chromatography and high-and low-resolution mass spectral (GC/MS) detection were used to accurately identify and quantify organic compounds in the sediment and water phases. Trace elements were measured using inductively coupled plasma-mass spectrometry and cold-vapor atomic fluorescence spectrometry methods. The loads of sediment, carbon, and chemicals were calculated for each storm and low-flow event sampled. Because only a few storm events were sampled, yearly loads of sediment were calculated from rating curves developed using historical SS and POC data. The average annual loads of sediment and carbon were calculated for the period 1975-2000, along with the loads for the selected water years being modeled as part of the New York New Jersey Harbor Estuary Program CARP. Comparison of loads calculated using the rating curve method to loads measured during the sampled storm events indicated that the rating curve method likely underpredicts annual loads. Average annual loads of suspended sediment in the tributaries were estimated to be 395,000 kilograms per year (kg/yr) in the Hackensack River, 417,000 kg/yr in the Elizabeth River, 882,000 kg/yr in the Rahway River, 22,700,000 kg/yr in the Passaic River, and 93,100,000 kg/yr in the Raritan River. Averag

Scientific Investigations Report↗
USGS2007

Water quality in the upper Anacostia River, Maryland: Continuous and discrete monitoring with simulations to estimate concentrations and yields, 2003-05

From 2003 through 2005, continuous and discrete waterquality data were collected at two stations on the Anacostia River in Maryland: Northeast Branch at Riverdale, Maryland (U.S. Geological Survey Station 01649500) and Northwest Branch near Hyattsville, Maryland (Station 01651000). Both stations are above the heads of tide for the river, and measurements approximately represent contributions of chemicals from the nontidal watersheds in the Anacostia River. This study was a cooperative effort between the U.S. Geological Survey, the Prince George’s County Department of Environmental Resources, the Maryland Department of the Environment, the U.S. Environmental Protection Agency, and George Mason University. Samples were collected for suspended sediment, nutrients, and trace metals; data were used to calculate loads of selected chemical parameters, and to evaluate the sources and transport processes of contaminants. Enrichment factors were calculated for some trace metals and used to interpret patterns of occurrence over different flow regimes. Some metals, such as cadmium, lead, and zinc, were slightly enriched as compared to global averages for shales; overall, median values of enrichment factors for all metals were approximately 15 to 35. Stepwise linear regression models were developed on log-transformed concentrations to estimate the concentrations of suspended sediment, total nitrogen, and total phosphorus from continuous data of discharge and turbidity. The use of multiple explanatory variables improved the predictions over traditional rating curves that use only streamflow as the explanatory variable, because other variables such as turbidity measure the hysteretic effects of fine-grained suspended sediment over storm hydrographs. Estimates of the concentrations of suspended sediment from continuous discharge and turbidity showed coefficients of determination for the predictions (multiple R2) of 0.95 and biases of less than 4 percent. Models to estimate the concentrations of total phosphorus and total nitrogen had lower values of multiple R2 than suspended sediment, but the estimated bias for all the models was similar. The models for total nitrogen and total phosphorus tended to under-predict high concentrations and to over-predict low concentrations as compared to measured values. Annual yields (loads per square area in kilograms per year per square kilometer) were estimated for suspended sediment, total nitrogen, and total phosphorus using the U.S. Geological Survey models ESTIMATOR and LOADEST. The model LOADEST used hourly time steps and allowed the use of turbidity, which is strongly correlated to concentrations of suspended sediment, as a predictor variable. Annual yields for total nitrogen and total phosphorus were slightly higher but similar to previous estimates for other watersheds of the Chesapeake Bay, but annual yields for suspended sediment were higher by an order of magnitude for the two Anacostia River stations. Annual yields of suspended sediment at the two Anacostia River stations ranged from 131,000 to 248,000 kilograms per year per square kilometer for 2004 and 2005. LOADEST estimates were similar to those determined with ESTIMATOR, but had reduced errors associated with the estimates.

Maryland↗
USGS2011

Evapotranspiration over spatially extensive plant communities in the Big Cypress National Preserve, southern Florida, 2007-2010

Evapotranspiration (ET) was quantified over plant communities within the Big Cypress National Preserve (BCNP) using the eddy covariance method for a period of 3 years from October 2007 to September 2010. Plant communities selected for study included Pine Upland, Wet Prairie, Marsh, Cypress Swamp, and Dwarf Cypress. These plant communities are spatially extensive in southern Florida, and thus, the ET measurements described herein can be applied to other humid subtropical locations such as the Everglades. The 3-year mean annual ET was about 1,000, 1,050, 1,100, 930, and 900 mm (millimeters) at the Dwarf Cypress, Wet Prairie, Cypress Swamp, Pine Upland, and Marsh sites, respectively. Spatial differences in annual ET were considerable due to the recovery of the Marsh site from extensive forest fire and drought conditions. Temporal variability in annual ET was relatively small at sites that were well watered (Dwarf Cypress, Wet Prairie, Cypress Swamp, Pine Upland) over the 3-year study. In other words, locations that were well watered appeared to have similar annual ET rates. Diurnal water-level variability was observed in response to ET and was less at flooded sites than at dry sites. For example, surface-water levels declined about 1.5 mm in response to ET at the flooded Cypress Swamp site during July 18-22, 2008 and declined about 10 mm in response to ET at the flooded Dwarf Cypress site from April 18-27, 2008. Specific yield was computed using ET estimates and diurnal water-level variability measured at the dry Pine Upland site as a check on the accuracy of the eddy covariance method. Water levels repeatedly dropped about 15 mm on average in response to ET at the Pine Upland site from April 27 to May 4, 2008. ET was about 3 mm on each of these days, resulting in a reasonable estimate for specific yield of 0.2 for the sandy soils at the Pine Upland site. Monthly ET estimates exhibited seasonal variation. ET was generally greatest between March to October when solar radiation was relatively large, and least from November to February when solar radiation was small. Monthly ET was greatest in the spring and summer at the Cypress Swamp site, reaching rates as large as 140 mm. The large ET rates at this site coincide with the most active period of cypress growth during late spring and early summer. Cypress trees begin to senesce in late summer reducing transpiration. Net radiation and available energy explained most of the variability in ET observed at all five sites. Mean annual and monthly net radiation varied among the sites in response to cloud cover and the albedo of the land surface and plant community. Net radiation was greatest at the Cypress Swamp site, averaging about 130 W/m 2 (watts per square meter) during the 3-year study. Net radiation was generally less at the Dwarf Cypress site, averaging about 115 W/m 2 over 3 years. The Dwarf Cypress site apparently has the largest albedo, which likely is due to the sparse canopy and a highly reflective, calcareous, periphyton-covered land surface. Furthermore, mean annual net radiation was least in the first year of the study, which likely was due to greater cloud cover during a relatively wet year. In contrast, net radiation was greatest in the second year of the study, which likely was due to less cloud cover during a relatively dry year.

Scientific Investigations Report↗
USGS2015

Discharge, suspended sediment, bedload, and water quality in Clear Creek, western Nevada, water years 2010-12

Clear Creek is a small stream that drains the eastern Sierra Nevada near Lake Tahoe, flows roughly parallel to the U.S. Highway 50 corridor, and discharges to the Carson River near Carson City, Nevada. Historical and ongoing development in the drainage basin is thought to be affecting Clear Creek and its sediment-transport characteristics. A baseline study from water years 2004–07 collected and evaluated data at three Clear Creek sampling sites. These data included discharge, selected water-quality parameters, and suspended-sediment concentrations, loads, and yields. This study builds on what was learned from the baseline study in water years 2004–07 and serves as a continuation of the data collection and analyses of the Clear Creek discharge regime and associated water-quality and sediment concentrations and loads during water years 2010–12. During this study, total annual sediment loads ranged from 355 tons per year in 2010 to 1,768 tons per year in 2011 and were significantly lower than the previous study (water years 2004–07). Bedload represented between 29 and 38 percent of total sediment load in water years 2010–12, and between 72 and 90 percent of the total sediment load in water years 2004–07, which indicates a decrease in bedload between study periods. Annual suspended-sediment loads in water years 2010–12 indicated no significant change from water years 2004–07. Mean daily discharge was significantly lower in water years 2010–12 than in waters years 2004–07 and may be the reason for the decrease in bedload that resulted in a lower total sediment load.

Nevada↗
USGS2016

Changes in streamflow characteristics in Wisconsin as related to precipitation and land use

Streamflow characteristics were determined for 15 longterm streamflow-gaging stations for the periods 1915–2008, 1915–68, and 1969–2008 to identify trends. Stations selected represent flow characteristics for the major river basins in Wisconsin. Trends were statistically significant at the 95 percent confidence level at 13 of the 15 streamflow-gaging stations for various streamflow characteristics for 1915–2008. Most trends indicated increases in low flows for streams with agriculture as the dominant land use. The three most important findings are: increases in low flows and average flows in agricultural watersheds, decreases in flood peak discharge for many streams in both agricultural and forested watersheds, and climatic change occurred with increasing annual precipitation and changes in monthly occurrence of precipitation. When the 1915–68 period is compared to the 1969–2008 period, the annual 7-day low flow increased an average of 60 percent for nine streams in agricultural areas as compared to a 15 percent increase for the five forested streams. Average annual flow for the same periods increased 23 percent for the agriculture streams and 0.6 percent for the forested streams. The annual flood peak discharge for the same periods decreased 15 percent for agriculture streams and 8 percent for forested streams. The largest increase in the annual 7-day low flow was 117 percent, the largest increase in annual average flow was 41 percent, and the largest decrease in annual peak discharge was 51 percent. The trends in streamflow characteristics affect frequency characteristics, which are used for a variety of design and compliance purposes. The frequencies for the 1969–2008 period were compared to frequencies for the 1915–68 period. The 7-day, 10-year (Q7, 10) low flow increased 91 percent for nine agricultural streams, while the five forested streams had an increase of 18 percent. The 100-year flood peak discharge decreased an average of 15 percent for streams in the agriculture area and 27 percent for streams in the forested area. Increases in low flow for agriculture streams are attributed to changes in agricultural practices and land use as well as increased precipitation. The decrease in annual flood peak discharge with increased annual precipitation is less clear, but is attributed to increased infiltration from changes in agricultural practices and climatic changes. For future low-flow studies, the 1969–2008 period should be used to determine low-flow characteristics since it represents current (2014) conditions and was generally free of significant trends.

Wisconsin↗
USGS2017

Streamflow characteristics and trends along Soldier Creek, Northeast Kansas

Historical data for six selected U.S. Geological Survey streamgages along Soldier Creek in northeast Kansas were used in an assessment of streamflow characteristics and trends. This information is required by the Prairie Band Potawatomi Nation for the effective management of tribal water resources, including drought contingency planning. Streamflow data for the period of record at each streamgage were used to assess annual mean streamflow, annual mean base flow, mean monthly flow, annual peak flow, and annual minimum flow. Annual mean streamflows along Soldier Creek were characterized by substantial year-to-year variability with no pronounced long-term trends. On average, annual mean base flow accounted for about 20 percent of annual mean streamflow. Mean monthly flows followed a general seasonal pattern that included peak values in spring and low values in winter. Annual peak flows, which were characterized by considerable year-to-year variability, were most likely to occur in May and June and least likely to occur during November through February. With the exception of a weak yet statistically significant increasing trend at the Soldier Creek near Topeka, Kansas, streamgage, there were no pronounced long-term trends in annual peak flows. Annual 1-day, 30-day, and 90-day mean minimum flows were characterized by considerable year-to-year variability with no pronounced long-term trend. During an extreme drought, as was the case in the mid-1950s, there may be zero flow in Soldier Creek continuously for a period of one to several months.

Kansas↗