In the midwestern United States, expansion of corn cropping for ethanol production during the last decade, led to increasing N application rates in the 2000’s during a period of extreme variability of annual precipitation. The analysis of several decades of nitrate concentration and flow data from 10 major Iowa Rivers indicated that flow-normalized concentrations of nitrate+nitrite-N decreased from 2000 to 2012 in all basins. The recent declining concentration trends can be attributed to both very high and very low discharge in the 2000s and to the long (e.g., 8 year) subsurface residence times in some basins. Dilution of N and depletion of stored N occurs in years with high discharge. Reduced N transport and increased N storage occurs in low-discharge years. Central Iowa basins had the greatest reduction in flow-normalized concentrations, likely because of smaller storage volumes and shorter residence times. Effects of land-use changes on the water quality of major Iowa
Rivers may not be noticeable for years or decades in peripheral basins of Iowa, and may be obscured in the central basins where extreme flows strongly affect annual concentration trends.
Scientists from the USGS North Dakota Water Science Center and North Dakota State University conducted research on changes in run-off in the north central United States over the last century. Precipitation, temperature and streamflow records were used to compare changes in precipitation potential evapotranspiration to changes in runoff within 25 stream basins including 7 stream basins in Iowa
Research has shown that environmental contamination from pharmaceuticals is a global concern. The USGS Toxic Substances Hydrology Program is a world leader in the study of the occurrence, fate, and effects of pharmaceutical contamination.
To promote the collection and disposal of unused/unwanted drugs in a safe and approved manner, The Great Lakes Clean Water Organization (GLCW) has developed the Yellow Jug Old Drugs/256 Program. GLWC and Stone Bridge Productions, with financial support from Michigan DEQ, teamed up to produce a documentary focusing on the emerging issue of pharmaceuticals in water and what is being done to help prevent such contamination.
As part of this documentary, Dana Kolpin (research hydrologist from the USGS Iowa Water Science Center and team leader of the Toxics Program's Contaminants of Emerging Concern Project) was interviewed to provide his expertise on the topic of pharmaceuticals in the environment. His interview took place at Fourmile Creek in central Iowa (a stream being used by the USGS Toxics Program as a field laboratory to understand fate and effects of pharmaceuticals).
This documentary is being broadcast on all Michigan PBS stations in November and December 2013.
Heavy snow and early spring rainfall in the upper part of the Missouri River Basin in 2011 exceeded the storage capacity of the Missouri River main stem reservoirs and unprecedented amounts of water were released into the lower parts of the basin resulting in record floods from June through September on the Missouri River in Iowa and Nebraska and extending into Kansas and Missouri. Runoff from the Missouri River Basin in April through September 2011 was 68,400,000 acre feet that was only exceeded during flooding in 1993 when runoff was 90,700,000 acre feet. Nitrate and total phosphorus concentrations in the Missouri River and selected tributaries during the flood generally were within the expected range of concentrations measured during the last 30 years. The Missouri River transported an estimated 87,700 tons of nitrate and 41,900 tons of total phosphorus to the Mississippi River from April through September 2011. This was less than 20 percent of the combined total nitrate flux and was about 39 percent of the combined total phosphorus flux from the Upper Mississippi and Missouri River Basins. Substantially more nitrate but less total phosphorus was transported from the Missouri River Basin during the historic 1993 than during the 2011 flood.
A total of 116 water samples were collected at 32 streams and 3 wastewater treatment plants during 2010.
The detections of mycotoxins were nearly ubiquitous (94% of samples) even though basin size spanned 4 orders of magnitude.
The most frequently detected mycotoxins included deoxynivalenol (77%), nivalenol (59%), and beauvericin (43%).
Levels exceeding 100 ng/L were measured during spring snowmelt conditions in agricultural settings and in WWTP effluent.
Both diffuse and point sources are important environmental pathways for mycotoxin transport to streams.
This report presents estimates of nitrate concentration and flux at eight sites in the Mississippi river basin from 1980 through 2010. It also examines the variability of expected nitrate concentrations in relation to season and streamflow at each of the eight sites for a recent period from 2000 through 2010.
From April through July 2011, the U.S. Geological Survey collected surface-water samples from 69 water-quality stations and 3 flood-control structures in 4 major subbasins of the Mississippi River Basin to characterize the water quality during the 2011 Mississippi River flood. Most stations were sampled at least monthly for field parameters suspended sediment, nutrients, and selected pesticides. Samples were collected at daily to biweekly frequencies at selected sites in the case of suspended sediment. Hydro-carbon analysis was performed on samples collected at two sites in the Atchafalaya River Basin to assess the water-quality implications of opening the Morganza Floodway. Water-quality samples obtained during the flood period were collected at flows well above normal streamflow conditions at the majority of the stations throughout the Mississippi River Basin and its subbasins.
This report provides information about selection and use of UV nitrate sensors to facilitate the collection of high-quality nitrate nitrogen concentration data. This report addresses the operating principles, key features and sensor design, sensor characterization techniques and typical interferences, and approaches for sensor deployment. Key sections in this report address maintenance and calibration protocols, quality-assurance techniques, and data formats and reporting. Although the focus of this report is UV nitrate sensors, many of the principles can be applied to other in situ optical sensors for water-quality studies.
Learn About the Land: RAGBRAI 2013 Brochures
Once again, the USGS, Iowa Water Science Center, the IDNR Geological & Water Survey and the Iowa Limestone Producers have teamed up to provide the Learn About The Land daily trip logs describing interesting landscape, geologic, and other natural and historical features and resources along the RAGBRAI trail. Look for USGS volunteers as they distribute these brochures in the RAGBRAI campgrounds.
Click on each days brochure to learn more about the land of Iowa.
On the Welcome to StreamStats webpage, click on the State Applications link and on the next webpage click on the State of Iowa on the map of the United States to access the introductory page for Iowa StreamStats. Please read the Warnings on the introductory page to become familiar with Iowa StreamStats. Click on the Interactive Map link to open Iowa StreamStats.
StreamStats is a U.S. Geological Survey Web-based Geographic Information System (GIS) that provides users with access to an assortment of analytical tools that are useful for water-resources planning and management, and for engineering design applications, such as the design of bridges. StreamStats allows users to easily obtain streamflow statistics, drainage-basin characteristics, and other information for user-selected sites on streams.Users can select stream site locations of interest from an interactive map and can obtain information for these locations. If a user selects the location of a USGS streamgage, the user will receive previously published information for the streamgage from a database. If a user selects a location where no data are available (an ungaged site), StreamStats will delineate the drainage-basin boundary, measure basin characteristics and estimate streamflow statistics for the site. These estimates assume natural flow conditions at the site. StreamStats also allows users to identify stream reaches that are upstream or downstream from user-selected sites, and to identify and obtain information for locations along the streams where activities that may affect streamflow conditions are occurring.The results are presented in a table and a map showing the basin-boundary outline. The estimates are applicable for stream sites not significantly affected by regulation, diversions, channelization, backwater, or urbanization.
A variety of individuals from water resource managers to recreational users need streamflow information for planning and decisionmaking at locations where there are no streamgages. To address this problem, two statistically based methods, the Flow Duration Curve Transfer method and the Flow Anywhere method, were developed for statewide application and the two physically based models, the Precipitation Runoff Modeling-System and the Soil and Water Assessment Tool, were only developed for application for the Cedar River Basin. Observed and estimated streamflows for the two methods and models were compared for goodness of fit at 13 streamgages modeled in the Cedar River Basin by using the Nash-Sutcliffe and the percent-bias efficiency values.
A statewide study was performed to develop regional regression equations for estimating selected annual exceedance-probability statistics for ungaged stream sites in Iowa. The study area comprises streamgages located within Iowa and 50 miles beyond the State’s borders. Annual exceedance-probability estimates were computed for 518 streamgages by using the expected moments algorithm to fit a Pearson Type III distribution to the logarithms of annual peak discharges for each streamgage using annual peak-discharge data through 2010. The estimation of the selected statistics included a Bayesian weighted least-squares/generalized least-squares regression analysis to update regional skew coefficients for the 518 streamgages. Low-outlier and historic information were incorporated into the annual exceedance-probability analyses, and a generalized Grubbs-Beck test was used to detect multiple potentially influential low flows. Also, geographic information system software was used to measure 59 selected basin characteristics for each streamgage.
Regional regression analysis, using generalized least-squares regression, was used to develop a set of equations for each flood region in Iowa for estimating discharges for ungaged stream sites with 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities, which are equivalent to annual flood-frequency recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years, respectively. A total of 394 streamgages were included in the development of regional regression equations for three flood regions (regions 1, 2, and 3) that were defined for Iowa based on landform regions and soil regions.
The U.S. Geological Survey, in cooperation with the Iowa Department of Natural Resources, used the Soil and Water Assessment Tool to simulate streamflow and nitrate loads within the Cedar River Basin, Iowa. The goal was to assess the ability of the Soil and Water Assessment Tool to estimate streamflow and nitrate loads in gaged and ungaged basins in Iowa. The Cedar River Basin model uses measured streamflow data from 12 U.S. Geological Survey streamflow-gaging stations for hydrology calibration. The U.S. Geological Survey software program, Load Estimator, was used to estimate annual and monthly nitrate loads based on measured nitrate concentrations and streamflow data from three Iowa Department of Natural Resources Storage and Retrieval/Water Quality Exchange stations, located throughout the basin, for nitrate load calibration. The hydrology of the model was calibrated for the period of January 1, 2000, to December 31, 2004, and validated for the period of January 1, 2005, to December 31, 2010.
In this study, Lagrangian sampling, in which the same approximate parcel of water is tracked as it moves downstream, was conducted at Boulder Creek, Colorado and Fourmile Creek, Iowa to determine in-stream transport and attenuation of more than 200 organic contaminants (including metal complexing agents, nonionic surfactant degradates, personal care products, pharmaceuticals, steroidal hormones, and pesticides) discharged from two secondary WWTPs. Similar stream reaches were evaluated, and samples were collected at multiple sites during summer and spring hydrologic conditions. After accounting for in-stream dilution, a complex mixture of contaminants showed little attenuation and was persistent in the receiving streams at concentrations with potential ecosystem implications.
The concentrations of electron donors and sediment propoerties of aquifer sediments near the South Fork Iowa River were conducted on 50 samples collected from below the water table in 11 boreholes. Samples were analyzed for gravel, sand (coarse, medium, and fine), silt, clay, Munsell soil color, inorganic carbon content, and for the following electron donors: organic carbon, ferrous iron, and inorganic sulfide. Sediment mineralogy was analyzed by using x-ray diffraction (XRD)
« Previous |