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Some statistical tools in hydrology
This chapter of 'Techniques of Water-Resources Investigations' provides background material needed for understanding the statistical procedures most useful in hydrology; it furnishes detailed procedures, with examples, of regression analyses; it describes analysis of variance and covariance and discusses the characteristics of hydrologic data.
Methods for analysis of selected metals in water by atomic absorption
This manual describes atomic-absorption-spectroscopy methods for determining calcium, copper, lithium, magnesium, manganese, potassium, sodium, strontium and zinc in atmospheric precipitation, fresh waters, and brines. The procedures are intended to be used by water quality laboratories of the Water Resources Division of the U.S. Geological Survey. Detailed procedures, calculations, and methods for the preparation of reagents are given for each element along with data on accuracy, precision, and sensitivity. Other topics discussed briefly are the principle of atomic absorption, instrumentation used, and special analytical techniques.
pH measurement of low-conductivity waters
pH is an important and commonly measured parameter of precipitation and other natural waters. The various sources of errors in pH measurement were analyzed and procedures for improving the accuracy and precision of pH measurements in natural waters with conductivities of < 100 uS/cm at 25 C are suggested. Detailed procedures are given for the preparation of dilute sulfuric acid standards to evaluate the performance of pH electrodes in low conductivity waters. A daily check of the pH of dilute sulfuric acid standards and deionized water saturated with a gas mixture of low carbon dioxide at partial pressure (air) prior to the measurement of the pH of low conductivity waters is suggested. (Author 's abstract)
Field and laboratory procedures used in a soil chronosequence study
In 1978, the late Denis Marchand initiated a research project entitled "Soil Correlation and Dating at the U.S. Geological Survey" to determine the usefulness of soils in solving geologic problems. Marchand proposed to establish soil chronosequences that could be dated independently of soil development by using radiometric and other numeric dating methods. In addition, by comparing dated chronosequences in different environments, rates of soil development could be studied and compared among varying climates and mineralogical conditions. The project was fundamental in documenting the value of soils in studies of mapping, correlating, and dating late Cenozoic deposits and in studying soil genesis. All published reports by members of the project are included in the bibliography. The project demanded that methods be adapted or developed to ensure comparability over a wide variation in soil types. Emphasis was placed on obtaining professional expertise and on establishing consistent techniques, especially for the field, laboratory, and data-compilation methods. Since 1978, twelve chronosequences have been sampled and analyzed by members of this project, and methods have been established and used consistently for analysis of the samples. The goals of this report are to: Document the methods used for the study on soil chronosequences, Present the results of tests that were run for precision, accuracy, and effectiveness, and Discuss our modifications to standard procedures. Many of the methods presented herein are standard and have been reported elsewhere. However, we assume less prior analytical knowledge in our descriptions; thus, the manual should be easy to follow for the inexperienced analyst. Each chapter presents one or more references of the basic principle, an equipment and reagents list, and the detailed procedure. In some chapters this is followed by additional remarks or example calculations. The flow diagram in figure 1 outlines the step-by-step procedures used to obtain and analyze soil samples for this study. The soils analyzed had a wide range of characteristics (such as clay content, mineralogy, salinity, and acidity). Initially, a major task was to test and select methods that could be applied and interpreted similarly for the various types of soils. Tests were conducted to establish the effectiveness and comparability of analytical techniques, and the data for such tests are included in figures, tables, and discussions. In addition, many replicate analyses of samples have established a "standard error" or "coefficient of variance" which indicates the average reproducibility of each laboratory procedure. These averaged errors are reported as percentage of a given value. For example, in particle-size determination, 3 percent error for 10 percent clay content equals 10 ± 0.3 percent clay. The error sources were examined to determine, for example, if the error in particle-size determination was dependent on clay content. No such biases were found, and data are reported as percent error in the text and in tables of reproducibility.
A procedure for estimating Bacillus cereus spores in soil and stream-sediment samples — A potential exploration technique
The presence of bacterial spores of the Bacillus cereus group in soils and stream sediments appears to be a sensitive indicator of several types of concealed mineral deposits, including vein-type gold deposits. The B. cereus assay is rapid, inexpensive, and inherently reproducible. The test, currently under investigation for its potential in mineral exploration, is recommended for use on a research basis. Among the aerobic spore-forming bacilli, only B. cereus and closely related strains produce an opaque zone in egg-yolk emulsion agar. This characteristic, also known as the Nagler of lecitho-vitellin reaction, has long been used to rapidly indentify and estimate presumptive B. cereus . The test is here adapted to permit rapid estimation of B. cereus spores in soil and stream-sediment samples. Relative standard deviation was 10.3% on counts obtained from two 40-replicate pour-plate determinations. As many as 40 samples per day can be processed. Enough procedural detail is included to permit investigation of the test in conventional geochemical laboratories using standard microbiological safety precautions.
Identifying the origin of waterbird carcasses in Lake Michigan using a neural network source tracking model
Avian botulism type E is responsible for extensive waterbird mortality on the Great Lakes, yet the actual site of toxin exposure remains unclear. Beached carcasses are often used to describe the spatial aspects of botulism mortality outbreaks, but lack specificity of offshore toxin source locations. We detail methodology for developing a neural network model used for predicting waterbird carcass motions in response to wind, wave, and current forcing, in lieu of a complex analytical relationship. This empirically trained model uses current velocity, wind velocity, significant wave height, and wave peak period in Lake Michigan simulated by the Great Lakes Coastal Forecasting System. A detailed procedure is further developed to use the model for back-tracing waterbird carcasses found on beaches in various parts of Lake Michigan, which was validated using drift data for radiomarked common loon ( Gavia immer ) carcasses deployed at a variety of locations in northern Lake Michigan during September and October of 2013. The back-tracing model was further used on 22 non-radiomarked common loon carcasses found along the shoreline of northern Lake Michigan in October and November of 2012. The model-estimated origins of those cases pointed to some common source locations offshore that coincide with concentrations of common loons observed during aerial surveys. The neural network source tracking model provides a promising approach for identifying locations of botulinum neurotoxin type E intoxication and, in turn, contributes to developing an understanding of the dynamics of toxin production and possible trophic transfer pathways.
Protocol for monitoring and analyzing pheromone-mediated behavioral response of sea lamprey in a natural system
Olfactory-mediated behaviors in fish are often examined in artificial microcosms that enable well-controlled treatments but fail to replicate environmental and social contexts. However, observing these behaviors in nature poses challenges. Here, we describe a protocol for recording sea lamprey (Petromyzon marinus) behaviors in a natural system. We describe steps for administering and verifying accurate odorant concentrations, surveying sea lamprey abundance, and tracking sea lamprey movements. We also detail procedures to analyze treatment effects on pheromone-mediated spawning in a high-density population.
How to overcome inter-electrode variability and instability to quantify dissolved oxygen, Fe(II), mn(II), and S(−II) in undisturbed soils and sediments using voltammetry
Background - Although uniquely capable of measuring multiple redox constituents nearly simultaneously with no or minimal sample pretreatment, voltammetry is currently underutilized in characterizing redox conditions in aquatic and terrestrial systems. Investigation of undisturbed media such as pore water requires a solid-state electrode, and such electrodes can be difficult to fabricate reproducibly. An approach to determine the concentrations of electroactive constituents using indirectly calibrated electrodes has been developed, but the protocol for and accuracy of this approach—the pilot ion method—has not been documented in detail. Results - A detailed procedure for testing electrode quality is provided, and the application and limitations of the pilot ion method have been documented. To quantify Fe(II) and Mn(II), subtraction of non-linear baseline functions from voltammetric signals produced better calibration curves than did linear baselines, enabled lower detection limits and reliable deconvolution of overlapping signals, and was successfully applied to sediment pore water signals. We observed that electrode sensitivities often vary by tens of percent, and that the sensitivity declines over time. The ratio of calibration slopes of Mn(II) to Fe(II) varied by no more than 11% from one Hg/Au electrode to another and Fe(II) concentrations predicted by the Mn(II) pilot ion were, on average, 13% different from their actual values. However, concentration predictions by the pilot ion method were worse for less than 15 μM Fe(II) (46% different on average). The ratio of calibration slopes of Mn(II) to S(−II) varied by almost 20% from one Hg/Au electrode to another, and S(−II) predicted concentrations were as much as 58% different from their actual values. These predictions of Fe(II) and S(−II) concentrations indicate that the accuracy of the pilot ion method depends on how independent calibration slope ratios are from the electrode used. At medium-to-high concentration for the ocean, naturally derived dissolved organic carbon did not significantly affect the baseline-corrected electrode response of Mn(II) and Fe(II), but did significantly affect the response of S(−II). Conclusions - Despite their intrinsic variability, Hg/Au electrodes fabricated by hand can be used to quantify O2, S(−II), Fe(II), and Mn(II) without calibrating every electrode for every constituent of interest. The pilot ion method can achieve accuracies to within 20% or less, provided that the underlying principle—the independence of slope ratios—is demonstrated for all voltammetric techniques used, and effects of the physicochemical properties of the system on voltammetric signals are addressed through baseline subtraction.
The U.S.G.S. phosphate-fluoride-iodate method for the determination of very small amounts of thorium in naturally occurring materials
Detailed procedures are presented for the determination of very small percentages of thorium. The methods are designed to determine 0.001% of thorium oxide as the lower limit and are applicable to nearly all types of rocks. For quantities below a milligram of ThO 2 , the thorium is determined nephelometrically as the iodate or photemetrically with p-dimethylamineasephenylarsonic acid. For quantities of thorium above one milligram of ThO 2 , the thorium is determined gravimetrically. A discussion of the important feature of the methods and a summary of the more important experimental work that lead to the adoption of the procedures.
U.S. Geological Survey Library classification system
The U.S. Geological Survey library classification system has been designed for an earth science library. It is a tool for assigning classification numbers to earth science and allied pure science library materials in order to collect these materials into related subject groups on the library shelves and arrange them alphabetically by author and title. It can also be used as a retrieval system to access these materials through the subject and visible geographic classification numbers. The classification scheme has been developed over the years since 1904 to meet the ever-changing needs of increased specialization and new areas of study in the earth sciences. This system contains seven schedules: Subject schedule Geological survey schedule Earth science periodical schedule Government documents periodical schedule General science periodical schedule Earth science maps schedule Geographic schedule A geographic number, from the geographic schedule, is distinguished from other numbers in the system in that it is always enclosed in parentheses; for example, (200) is the geographic number for the United States. The geographic number is used in conjunction with the six other previously listed schedules, and it represents slightly different nuances of meanings, in respect to geographic locale, for each schedule. When used with a subject number, the geographic number indicates the country, state, province, or region in which the research was made. The subject number, 203, geology, when combined with the geographic number, (200), for example 203(200), is the classification number for library materials on the geology of the United States. The geographic number, combined with the capital letter G, for example, G(211), is the classification number for an earth science periodical issued by a geological association or university geology department in the State of Maine. When the letter S is combined with a geographic number, for example, S(276), it represents a general science periodical for a university or association in California. When the letter P is combined with a geographic number, for example, P(200), it represents a governmental periodical issued by the United States Federal Government. Geographic numbers standing alone represent classification numbers for the publications of geological surveys; for example, (200) represents publications of the U.S. Geological Survey. Map call numbers have a geographic number preceded by the capital letter M, followed by an abbreviated subject number. For example: M(200)2 where: M = Map (200) = Geographic region of the United States 2 = Abbreviation for the subject number 203— geology. The introduction, which follows this abstract, provides detailed procedures on the construction of complete call numbers for works falling into the framework of the aforesaid classification schedules. The tables following the introduction can be quickly accessed through the use of the newly expanded subject index. The purpose of this publication is to provide the earth science community with a classification and retrieval system for earth science materials, to provide sufficient explanation of its structure and use, and to enable library staff and clientele to classify or access research materials in a library collection.
Users guide for the Water Resources Division bibliographic retrieval and report generation system
The WRDBIB Retrieval and Report-generation system has been developed by applying Multitrieve (CSD 1980, Reston) software to bibliographic data files. The WRDBIB data base includes some 9 ,000 records containing bibliographic citations and descriptors of WRD reports released for publication during 1968-1982. The data base is resident in the Reston Multics computer and may be accessed by registered Multics users in the field. The WRDBIB Users Guide provides detailed procedures on how to run retrieval programs using WRDBIB library files, and how to prepare custom bibliographic reports and author indexes. Users may search the WRDBIB data base on the following variable fields as described in the Data Dictionary: Authors, organizational source, title, citation, publication year, descriptors, and the WRSIC (accession) number. The Users Guide provides ample examples of program runs illustrating various retrieval and report generation aspects. Appendices include Multics access and file manipulation procedures; a ' Glossary of Selected Terms'; and a complete ' Retrieval Session ' with step-by-step outlines. (USGS)
Evaluation of the use of remote-sensing data to identify crop types and estimate irrigated acreage, Uvalde and Medina counties, Texas, 1989
Remote-sensing data were used to estimate that 190,000 acre-feet of water was pumped from the Edwards aquifer in 1989 to irrigate crops in Uvalde and Medina Counties. Landsat digital satellite images for March and July 1989 were combined and classified to identify the areas of crops irrigated with water from the Edwards aquifer in the two counties. Normalized difference, the difference between the infrared and red reflectance values divided by the total of those values, was used to discriminate vegetative from nonvegetative ground cover. The images subsequently were classified using maximum likelihood, an unsupervised classification procedure. Detailed vegetation distribution maps of two calibration sites in the study area, and boundaries of the areas probably irrigated in 1989, helped to interpret the results and to separate probable irrigated areas from the rest of the image. Results were verified using crop acreages reported by the U.S. Department of Agriculture, Agricultural Stabilization and Conservation Service (ASCS). The total areas for all irrigated crops estimated using remote-sensing data were about 8 percent higher for Uvalde County and about 4 percent higher for Medina County than the areas reported by the ASCS. Irrigated-crop areas subsequently were multiplied by the respective duties of water to calculate the total quantity of water pumped from the aquifer for irrigation. Pumpage did not differ for the two estimates of crop areas for Uvalde County and differed by about 3 percent for Medina County.
Methods for collection and analysis of geopressured geothermal and oil field waters
Present methods are described for the collection, preservation, and chemical analysis of waters produced from geopressured geothermal and petroleum wells. Detailed procedures for collection include precautions and equipment necessary to ensure that the sample is representative of the water produced. Procedures for sample preservation include filtration, acidification, dilution for silica, methyl isobutyl ketone (MIBK) extraction of aluminum, addition of potassium permanganate to preserve mercury, and precipitation of carbonate species as strontium carbonate for stable carbon isotopes and total dissolved carbonate analysis. Characteristics determined at the well site are sulfide, pH, ammonia, and conductivity. Laboratory procedures are given for the analysis of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, iron, manganese, zinc, lead, aluminum, .and mercury by atomic absorption and flame emission spectroscopy. Chloride is determined by silver nitrate titration and fluoride by ion-specific electrode. Bromide and iodide concentrations are determined by the hypochlorite oxidation method. Sulfate is analyzed by titration using barium chloride with thorin indicator after pretreatment with alumina. Boron and silica are determined colorimetrically by the carmine and molybdate-blue methods, respectively. Aliphatic acid anions (C2 through C5) are determined by gas chromatography after separation and concentration in a chloroform-butanol mixture.
The microgravimetric determination of acid-insoluble impurities in the complete analysis of small samples of acid-soluble minerals
The acid-insoluble impurities of small samples of minerals are determined by a microgravimetric procedure. A Schwarz von Bergkampf glass filter stick with paper filter medium is used to separate the insoluble material. The filtration apparatus and procedural details are described.
Method and importance of obtaining humic and fulvic acids of high purity
A detailed procedure incorporating centrifugation, pressure filtration, dialysis, resin exchange, and freeze drying is given for the extraction and purification of fulvic and humic acids from soils and sediments. By use of the procedure humic acids have been prepared which have less than 0.22 percent ash. The isolation of relatively ash-free natural organic matter preparations is an essential prerequisite to the characterization of organic reactivity in natural systems. Inorganic impurities of amorphous and crystalline clay minerals and various inorganic metal ions often lead to numerous complications and errors during experimentation with organic matter because the inorganic substances associated with the organic phase cause variable reactivity of the organic substances.
Guidelines on preparedness before, during, and after an ashfall
This document has been prepared by the International Volcanic Health Hazard Network (IVHHN), Cities and Volcanoes Commission, GNS Science and the United States Geological Survey (USGS) to promote the safety of those who experience volcanic ashfall. It details procedures to follow if warning of a volcanic ashfall is given, recommends what to do during ashfall, and what methods are most effective for cleaning up volcanic ash after the event.