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At least 109 records · Page 6Linked to original sources
USGS2010

Computing time-series suspended-sediment concentrations and loads from in-stream turbidity-sensor and streamflow data

Over the last decade, use of a method for computing suspended-sediment concentration and loads using turbidity sensors—primarily nephelometry, but also optical backscatter—has proliferated. Because an in- itu turbidity sensor is capa le of measuring turbidity instantaneously, a turbidity time series can be recorded and related directly to time-varying suspended-sediment concentrations. Depending on the suspended-sediment characteristics of the measurement site, this method can be more reliable and, in many cases, a more accurate means for computing suspended-sediment concentrations and loads than traditional U.S. Geological Survey computational methods. Guidelines and procedures for estimating time s ries of suspended-sediment concentration and loading as a function of turbidity and streamflow data have been published in a U.S. Geological Survey Techniques and Methods Report, Book 3, Chapter C4. This paper is a summary of these guidelines and discusses some of the concepts, s atistical procedures, and techniques used to maintain a multiyear suspended sediment time series.

Conference Paper↗
USGS1957

The application, technique, and theory of Gish-Rooney instruments, methods, and interpretation in electrical resistivity measurements

The foundations of electrical prospecting were laid by Fox (1830) and Barus (1882). The former discovered that electrical currents and potentials were developed by certain ore deposits in Cornwall, England. Fox made measurements of these potentials and determined the resistivities of the minerals and surrounding rocks also. The latter, invented the non-polarizing electrode with which he overcame the polarizing effects of direct current, and was able to trace and extend the Comstock lode. According to Slichter (1934, p.234), F. Neumann proposed as early as 1884 determining the resistivity of the earth by a four-electrode method nearly like our present technique, and carefully developed the mathematical theory of the method. Wells (1914) followed the work of Barus with studies of the electric activity in ore deposits. Ambronn (1926) gives an extensive bibliography of the early work in geophysics. The classical work of Wenner (1917) and, almost at the same time and independently, that of Schlumberger (1920) laid the foundations for resistivity measurements on the surface of the earth. While Schlumberger was actually making measurements of earth resistivity related to structural studies as early as 1912 in France, work in this country was slow in developing from the work of Wenner, but it was gaining adherents following the pioneering work of Kelley (1922) and Gish (1923). Probably the work of Gish and Rooney (1925) Who redesigned the apparatus of McCollum (1925) was the largest contributing cause in this country for the sudden interest and expansion of electrical methods. Their work was followed by many others in the late 1920's, some of which are: Gish (1926); Rooney and Gish (1927); Rooney (1927); Gish and Rooney (1927); Lee (1928); Hotchkiss, Rooney, and Fisher (1929); Weaver (1929); Lundberg (1929); Leonardon and. Kelley (1929); Crosby and Leonardon (1929); Carretta and Kelly (1929); Koenigsberger (1929}; Runkel (1928, 1929); Heiland (1929); and many others.

Open-File Report↗
USGS2021

An efficient method to calculate depth-integrated, phase-averaged momentum balances in non-hydrostatic models

Analysis of the mean (wave-averaged) momentum balance is a common approach used to explain the physical forcing driving wave set-up and mean currents in the nearshore zone. Traditionally this approach has been applied to phase-averaged models but has more recently been applied to phase-resolving models using post-processing, whereby model output is used to calculate each of the momentum terms. While phase-resolving models have the advantage of capturing the nonlinear properties of waves propagating in the nearshore (making them advantageous to enhance understanding of nearshore processes), the post-processing calculation of the momentum terms does not guarantee that the momentum balance closes. We show that this is largely due to the difficulty (or impossibility) of being consistent with the numerical approach. If the residual is of a similar magnitude as any of the relevant momentum terms (which is common with post-processing methods as we show), the analysis is largely compromised. Here we present a new method to internally calculate and extract the depth-integrated, mean momentum terms in the phase-resolving non-hydrostatic wave-flow model SWASH in a manner that is consistent with the numerical implementation. Further, we demonstrate the utility of the new method with two existing physical model studies. By being consistent with the numerical framework, the internal method calculates the momentum terms with a much lower residual at computer precision, combined with greatly reduced calculation time and output storage requirements compared to post-processing techniques. The method developed here allows the accurate evaluation of the depth-integrated, mean momentum terms of wave-driven flows while taking advantage of the more complete representation of the wave dynamics offered by phase-resolving models. Furthermore, it provides an opportunity for advances in the understanding of nearshore processes particularly at more complex sites where wave nonlinearity and energy transfers are important.

Ocean Modelling↗
USGS1990

Evaluation of selected methods for determining streamflow during periods of ice effect

Seventeen methods for estimating ice-affected streamflow are evaluated for potential use for the U.S. Geological Survey streamflow-gaging station network. The methods evaluated were identified by written responses from U.S. Geological Survey field offices and by a comprehensive literature search. The methods selected and techniques used for applying the methods are described in the report. The methods are evaluated by comparing estimated results to data collected at three streamflow-gaging stations in Iowa during the winter of 1987-88. Discharge measurements were obtained at 1- to 5-day intervals during the ice-affected periods at the three stations to define an accurate baseline record. Discharge records were compiled for each method based on data available assuming a 6-week field schedule. The methods are classified into two general categories, subjective and analytical, depending on whether individual judgement is necessary for method application. On the basis of results of the evaluation for the three Iowa stations, two of the subjective methods (discharge ratio and hydrographic-and-climatic comparison) were more accurate than the other subjective methods, and approximately as accurate as the best analytical method. Three of the analytical methods (index velocity, adjusted rating curve, and uniform flow) could potentially be used for streamflow-gaging stations where the need for accurate ice-affected discharge estimates justifies the expense of collecting additional field data. One analytical method (ice adjustment factor) may be appropriate for use for stations with extremely stable stage-discharge ratings and measuring sections. Further research is needed to refine the analytical methods. The discharge ratio and multiple regression methods produce estimates of streamflow for varying ice conditions using information obtained from the existing U.S. Geological Survey streamflow-gaging network.

Iowa↗
USGS1992

Evaluation of selected methods for determining streamflow during periods of ice effect

Seventeen methods for estimating ice-affected streamflow are evaluated for potential use with the U.S. Geological Survey streamflow-gaging station network. The methods evaluated were identified by written responses from U.S. Geological Survey field offices and by a comprehensive literature search. The methods selected and techniques used for applying the methods are described in this report. The methods are evaluated by comparing estimated results with data collected at three streamflow-gaging stations in Iowa during the winter of 1987-88. Discharge measurements were obtained at 1- to 5-day intervals during the ice-affected periods at the three stations to define an accurate baseline record. Discharge records were compiled for each method based on data available, assuming a 6-week field schedule. The methods are classified into two general categories-subjective and analytical--depending on whether individual judgment is necessary for method application. On the basis of results of the evaluation for the three Iowa stations, two of the subjective methods (discharge ratio and hydrographic-and-climatic comparison) were more accurate than the other subjective methods and approximately as accurate as the best analytical method. Three of the analytical methods (index velocity, adjusted rating curve, and uniform flow) could potentially be used at streamflow-gaging stations, where the need for accurate ice-affected discharge estimates justifies the expense of collecting additional field data. One analytical method (ice-adjustment factor) may be appropriate for use at stations with extremely stable stage-discharge ratings and measuring sections. Further research is needed to refine the analytical methods. The discharge-ratio and multiple-regression methods produce estimates of streamflow for varying ice conditions using information obtained from the existing U.S. Geological Survey streamflow-gaging network.

Iowa↗
USGS2016

Assessing groundwater depletion and dynamics using GRACE and InSAR: Potential and limitations

In the last decade, remote sensing of the temporal variation of ground level and gravity has improved our understanding of groundwater dynamics and storage. Mass changes are measured by GRACE (Gravity Recovery and Climate Experiment) satellites, whereas ground deformation is measured by processing synthetic aperture radar satellites data using the InSAR (Interferometry of Synthetic Aperture Radar) techniques. Both methods are complementary and offer different sensitivities to aquifer system processes. GRACE is sensitive to mass changes over large spatial scales (more than 100,000 km 2 ). As such, it fails in providing groundwater storage change estimates at local or regional scales relevant to most aquifer systems, and at which most groundwater management schemes are applied. However, InSAR measures ground displacement due to aquifer response to fluid-pressure changes. InSAR applications to groundwater depletion assessments are limited to aquifer systems susceptible to measurable deformation. Furthermore, the inversion of InSAR-derived displacement maps into volume of depleted groundwater storage (both reversible and largely irreversible) is confounded by vertical and horizontal variability of sediment compressibility. During the last decade, both techniques have shown increasing interest in the scientific community to complement available in situ observations where they are insufficient. In this review, we present the theoretical and conceptual bases of each method, and present idealized scenarios to highlight the potential benefits and challenges of combining these techniques to remotely assess groundwater storage changes and other aspects of the dynamics of aquifer systems.

Groundwater↗
USGS2015

Shifts in the eruptive styles at Stromboli in 2010–2014 revealed by ground-based InSAR data

Ground-Based Interferometric Synthetic Aperture Radar (GBInSAR) is an efficient technique for capturing short, subtle episodes of conduit pressurization in open vent volcanoes like Stromboli (Italy), because it can detect very shallow magma storage, which is difficult to identify using other methods. This technique allows the user to choose the optimal radar location for measuring the most significant deformation signal, provides an exceptional geometrical resolution, and allows for continuous monitoring of the deformation. Here, we present and model ground displacements collected at Stromboli by GBInSAR from January 2010 to August 2014. During this period, the volcano experienced several episodes of intense volcanic activity, culminated in the effusive flank eruption of August 2014. Modelling of the deformation allowed us to estimate a source depth of 482 ± 46 m a.s.l. The cumulative volume change was 4.7 ± 2.6 × 105 m3. The strain energy of the source was evaluated 3–5 times higher than the surface energy needed to open the 6–7 August eruptive fissure. The analysis proposed here can help forecast shifts in the eruptive style and especially the onset of flank eruptions at Stromboli and at similar volcanic systems (e.g. Etna, Piton de La Fournaise, Kilauea).

Stromboli↗
USGS2012

A multi-metric assessment of environmental contaminant exposure and effects in an urbanized reach of the Charles River near Watertown, Massachusetts

The Charles River Project provided an opportunity to simultaneously deploy a combination of biomonitoring techniques routinely used by the U.S. Geological Survey National Water Quality Assessment Program, the Biomonitoring of Environmental Status and Trends Project, and the Contaminant Biology Program at an urban site suspected to be contaminated with polycyclic aromatic hydrocarbons. In addition to these standardized methods, additional techniques were used to further elucidate contaminant exposure and potential impacts of exposure on biota. The purpose of the study was to generate a comprehensive, multi-metric data set to support assessment of contaminant exposure and effects at the site. Furthermore, the data set could be assessed to determine the relative performance of the standardized method suites typically used by the National Water Quality Assessment Program and the Biomonitoring of Environmental Status and Trends Project, as well as the additional biomonitoring methods used in the study to demonstrate ecological effects of contaminant exposure. The Contaminant Effects Workgroup, an advisory committee of the U.S. Geological Survey/Contaminant Biology Program, identified polycyclic aromatic hydrocarbons as the contaminant class of greatest concern in urban streams of all sizes. The reach of the Charles River near Watertown, Massachusetts, was selected as the site for this study based on the suspected presence of polycyclic aromatic hydrocarbon contamination and the presence of common carp ( Cyprinus carpio ), largemouth bass ( Micropterus salmoides ), and white sucker ( Catostomus commersoni ). All of these fish have extensive contaminant-exposure profiles related to polycyclic aromatic hydrocarbons and other environmental contaminants. This project represented a collaboration of universities, Department of the Interior bureaus including multiple components of the USGS (Biological Resources Discipline and Water Resources Discipline Science Centers, the Contaminant Biology Program, and the Status and Trends of Biological Resources Program), and the U.S. Fish and Wildlife Service. Samples for analyzing water chemistry, sediment chemistry and toxicity, fish community structure, tissue chemistry, and fish (20 carp, 20 bass, and 40 white sucker) and invertebrate pathology were collected in late August, 2005. This report provides results from the analyses of fish pathology, biomarkers of exposure and effects (reproductive, carcinogenic, genotoxic, and immunologic), sediment chemistry, toxicity, and fish and invertebrate community structure.

Massachusetts↗
USGS2010

Implementation of local grid refinement (LGR) for the Lake Michigan Basin regional groundwater-flow model

The U.S. Geological Survey is evaluating water availability and use within the Great Lakes Basin. This is a pilot effort to develop new techniques and methods to aid in the assessment of water availability. As part of the pilot program, a regional groundwater-flow model for the Lake Michigan Basin was developed using SEAWAT-2000. The regional model was used as a framework for assessing local-scale water availability through grid-refinement techniques. Two grid-refinement techniques, telescopic mesh refinement and local grid refinement, were used to illustrate the capability of the regional model to evaluate local-scale problems. An intermediate model was developed in central Michigan spanning an area of 454 square miles (mi2) using telescopic mesh refinement. Within the intermediate model, a smaller local model covering an area of 21.7 mi2 was developed and simulated using local grid refinement. Recharge was distributed in space and time using a daily output from a modified Thornthwaite-Mather soil-water-balance method. The soil-water-balance method derived recharge estimates from temperature and precipitation data output from an atmosphere-ocean coupled general-circulation model. The particular atmosphere-ocean coupled general-circulation model used, simulated climate change caused by high global greenhouse-gas emissions to the atmosphere. The surface-water network simulated in the regional model was refined and simulated using a streamflow-routing package for MODFLOW. The refined models were used to demonstrate streamflow depletion and potential climate change using five scenarios. The streamflow-depletion scenarios include (1) natural conditions (no pumping), (2) a pumping well near a stream; the well is screened in surficial glacial deposits, (3) a pumping well near a stream; the well is screened in deeper glacial deposits, and (4) a pumping well near a stream; the well is open to a deep bedrock aquifer. Results indicated that a range of 59 to 50 percent of the water pumped originated from the stream for the shallow glacial and deep bedrock pumping scenarios, respectively. The difference in streamflow reduction between the shallow and deep pumping scenarios was compensated for in the deep well by deriving more water from regional sources. The climate-change scenario only simulated natural conditions from 1991-2044, so there was no pumping stress simulated. Streamflows were calculated for the simulated period and indicated that recharge over the period generally increased from the start of the simulation until approximately 2017, and decreased from then to the end of the simulation. Streamflow was highly correlated with recharge so that the lowest streamflows occurred in the later stress periods of the model when recharge was lowest.

Scientific Investigations Report↗
USGS2024

Introduction and methods of analysis for peak streamflow trends and their relation to changes in climate in Illinois, Iowa, Michigan, Minnesota, Missouri, Montana, North Dakota, South Dakota, and Wisconsin

Flood-frequency analysis, also called peak-flow frequency or flood-flow frequency analysis, is essential to water resources management applications including critical structure design and floodplain mapping. Federal guidelines for doing flood-frequency analyses are presented in a U.S. Geological Survey Techniques and Methods Report known as Bulletin 17C. A basic assumption within Bulletin 17C is that for drainage basins without major hydrologic alterations, statistical properties of the distribution of annual peak streamflows (peak flows) are stationary; that is, the mean, variance, and skew are constant. The stationarity assumption has been widely accepted within the flood-frequency community; however, a better understanding of long-term climatic persistence and concerns about potential climate change and land-use change has caused a reexamination of the stationarity assumption. Flood-frequency analyses that do not incorporate observed trends and abrupt changes may result in a poor representation of the true flood risk. Bulletin 17C does not offer guidance for incorporating nonstationarities when estimating floods, and it describes a need for studies that incorporate changing climate or basin characteristics. In response to this need and a history of concern regarding nonstationarity peak flows in the region, this study was done by the U.S. Geological Survey, in cooperation with the Departments of Transportation of Illinois, Iowa, Michigan, Minnesota, Missouri, South Dakota, and Wisconsin; the Montana Department of Natural Resources and Conservation; and the North Dakota Department of Water Resources, to assess potential nonstationarity in peak flows in the north-central United States. This chapter summarizes the methods used to detect hydroclimatic changes in peak-flow data in the study region. A wide range of analyses and statistical approaches are applied to document the primary mechanisms controlling floods and characterize temporal changes in hydroclimatic variables and peak flow. Four periods were selected for analysis of peak flow, daily streamflow, and climate data. The periods are (1) a 100-year period, 1921–2020; (2) a 75-year period, 1946–2020; (3) a 50-year period, 1971–2020; and (4) a 30-year period, 1991–2020. The climate data consist of monthly time series estimates of temperature, precipitation, potential evapotranspiration, actual evapotranspiration, snowfall, soil moisture storage, snow water equivalent, and runoff on a 3.1-mile by 3.1-mile grid for the conterminous United States. Statistical and graphical analyses were used to investigate potential changes in hydrology and climate. The starting point for these analyses was the initial data analysis of peak flow described in Bulletin 17C, which includes plotting the peak flow and checking for autocorrelation, monotonic trends, and changes points. Analyses were added to examine additional features in the data. To examine potential causal drivers of changes, the climate data were analyzed graphically and statistically. Results are provided in a U.S. Geological Survey data release. The study limitations are documented for users of the results.

Iowa, Illinois, Michigan, Missouri, Minnesota, Mon↗
USGS2025

Preparation and analysis methods for fish tissue collected from Lake Koocanusa, Montana

Lake Koocanusa, a reservoir, receives mine wastes from metallurgical coal mines in the Elk River Valley of British Columbia, Canada. Selenium and other elements discharged by the mines into the waters of the United States can pose unknown risks to aquatic life. The U.S. Geological Survey Wyoming-Montana Water Science Center can collaborate with Montana Fish, Wildlife and Parks and other State and Federal agencies to design studies and to collect fish tissues to help fill this knowledge gap. This report describes the processes, techniques, and methods used to collect and analyze fish tissue collected from Lake Koocanusa; and procedures used to review and manage data, including quality assurance and quality control procedures used by the U.S. Geological Survey Wyoming-Montana Water Science Center and supporting analytical laboratories. These fish tissue collections began in 2021.

Montana↗
USGS2025

The acoustic-Doppler current profiler (ADCP): A comprehensive tool for river-reach hydromorphodynamics

This paper introduces the use of acoustic Doppler current profiler (ADCP) measurements as input for the Acoustic Mapping Velocimetry (AMV) method, a technique for characterizing the dynamics of riverine bedforms. The performance of this new approach, ADCP-AMV, is compared with input from a multibeam echosounder through a field study conducted on the Mississippi River (USA). A virtual ADCP tool has been created to support the ADCP-AMV measurements with optimal data density predictions. To the authors’ knowledge, this is the first time ADCP measurements have been used in conjunction with the AMV dune-tracking method. Subsequently, the paper discusses the coupling of ADCP-AMV measurements with ancillary data extracted from the ADCP. These ancillary data are processed using previously developed protocols to characterize hydrodynamics and the suspended sediment distribution in the water column. This paper emphasizes the capability of ADCPs to characterize open-channel river hydromorphodynamic parameters with high spatiotemporal resolution. Recommendations to accurately and efficiently acquire these multi-variable measurements and derived datasets are discussed.

Tennessee↗
USGS2010

Assessing the validity of the channel model of fracture aperture under field conditions

I n recent investigations of fluid and solute movement in discrete fractures, spatial heterogeneity of the fracture aperture has been conceptualized as a series of noninterconnecting constant aperture flow paths, or channels. Two methods of estimating the distribution of the aperture sizes are presented using information from a single-hole pumping test and a radially converging tracer test. The first method uses the transmissivity of the fracture and mean arrival time of the tracer, while the second method uses the mean and variance of the solute arrival time. If the fracture can be conceptualized as a series of nonintersecting flow paths of constant aperture, the two methods should yield identical estimates for the parameters of the distribution. The validity of the channel model can be assessed by comparing the parameters of the distribution that are estimated by the two methods. This technique was demonstrated using hydraulic and tracer tests conducted in a discrete, areally extensive, horizontal fracture in the Silurian dolomite in the northeastern Illinois. A lognormal and a truncated gamma distribution were used to describe the distribution of constant aperture flow paths. The lognormal distribution could not reproduce the abrupt rising limb and maximum rate of mass arrival that characterized the tracer tests. The gamma distribution more accurately predicted the shape of the breakthrough curves; however, the two methods of estimating the parameters of the distribution provided significantly different estimates of the variances of the aperture sizes. The mean aperture as estimated by the two methods was similar. The difference in the variance of the aperture as estimated by the two methods indicates that alternative conceptual models of aperture heterogeneity are required to more accurately describe both fluid and solute movement in this field situation.

Water Resources Research↗
USGS2004

Novel geophysical and geochemical techniques used to study submarine groundwater discharge in Biscayne Bay, Florida

Introduction Submarine groundwater discharge (SGD) is a problem of major proportions on a world-wide scale. The ubiquitous nature of SGD along varied coastlines and its importance to coastal water and geochemical budgets have recently been thrust into the global spotlight . For example, the discharge of nutrient-enriched groundwater into coastal waters may cause nutrient imbalances that can lead to eutrophication or near-shore micro-organism blooms . Similarly, SGD can also directly affect threatened coastal freshwater resources and impact fragile coastal ecosystems, such as coral reefs. Recently, much effort has been devoted to developing and adapting new tracer techniques and methods for the identification and quantification of SGD. As the discharge of coastal groundwater most often occurs as diffuse seepage rather than through a single vent feature, assessing SGD has remained difficult for both oceanographers and hydrologists alike. Burnett and colleagues have developed a systematic approach to investigate SGD by using a combination of both physical seepage measurements and a suite of naturally occurring isotopic tracers in the U/Th decay chain – 222 Rn and 223,224,226,228 Ra. Manheim et al. further extended SGD investigations by adapting geophysical resistivity techniques to examine fine-scale change in conductivity fields within coastal sediments. Such streaming resistivity profiling has been successfully applied to identify sites of SGD, as well as the dynamic position of the fresh water/saltwater interface.

Florida↗
USGS1999

New method for the direct determination of dissolved Fe(III) concentration in acid mine waters

A new method for direct determination of dissolved Fe(III) in acid mine water has been developed. In most present methods, Fe(III) is determined by computing the difference between total dissolved Fe and dissolved Fe(II). For acid mine waters, frequently Fe(II) ≫ Fe(III); thus, accuracy and precision are considerably improved by determining Fe(III) concentration directly. The new method utilizes two selective ligands to stabilize Fe(III) and Fe(II), thereby preventing changes in Fe reduction−oxidation distribution. Complexed Fe(II) is cleanly removed using a silica-based, reversed-phase adsorbent, yielding excellent isolation of the Fe(III) complex. Iron(III) concentration is measured colorimetrically or by graphite furnace atomic absorption spectrometry (GFAAS). The method requires inexpensive commercial reagents and simple procedures that can be used in the field. Calcium(II), Ni(II), Pb(II), Al(III), Zn(II), and Cd(II) cause insignificant colorimetric interferences for most acid mine waters. Waters containing >20 mg of Cu/L could cause a colorimetric interference and should be measured by GFAAS. Cobalt(II) and Cr(III) interfere if their molar ratios to Fe(III) exceed 24 and 5, respectively. Iron(II) interferes when its concentration exceeds the capacity of the complexing ligand (14 mg/L). Because of the GFAAS elemental specificity, only Fe(II) is a potential interferent in the GFAAS technique. The method detection limit is 2 μg/L (40 nM) using GFAAS and 20 μg/L (0.4 μM) by colorimetry.

Environmental Science & Technology↗
USGS1995

A strategy for delineating the area of ground-water contribution to wells completed in fractured bedrock aquifers in Pennsylvania

Delineating a contributing area to a well completed in a fractured bedrock aquifer in Pennsylvania is difficult because the hydrogeologic characteristics of fractured rocks are extremely complex. Because of this complexity, a single method or technique to delineate a contributing area will not be applicable for all wells completed in fractured-bedrock aquifers. Therefore, a strategy for refining the understanding of boundary conditions and major heterogeneities that control ground-water flow and sources of water to a supply well is suggested. The strategy is based on developing and refining a conceptual model for the sources of water to the well. Specifically, the strategy begins with an initial conceptual model of the ground-water-flow system, then requires the collection of hydrogeologic information to refine the conceptual model in a stepwise manner from one or more of sic categories: (1) hydrogeologic mapping, (2) water-level and streamflow measurements, (3) geochemistry, (4) geophysics and borehole flowmetering, (5) aquifer testing, and (6) tracer testing. During the refinement process, the applicability of treating the fratured-rock aquifer as a hydrologic continuum is evaluated, and the contributing area is delineated. Choice of the method used to delineate the contributing area is less important than insuring that the method is consistent with the refined conceptual model. By use of such a strategy, the improved understanding of the ground-water-flow system will lead to a technically defensible delineation of the contributing area.

Water-Resources Investigations Report↗
USGS2025

Adaptive instrument design strategy for collecting water, sediment samples and stage data in remote, ephemeral arroyos in the arid southwestern United States

Methods for collecting water, suspended sediment samples, and streamflow from rivers and streams have been documented in the literature by various science agencies. However, some projects may require data collected in difficult conditions including remote sites, sites that have limited accessibility during storms, and streamflow that occurs rarely. For these studies, adaptive approaches to sampler instrument design can yield valuable sample and streamflow data previously unobtainable. Tracking the source(s) of metals to the San Juan River required water chemistry samples, suspended sediment samples, and streamflow data collected on 28 ephemeral arroyos and five perennial streams. These tributaries to the San Juan River presented many challenges because of their remote locations, inaccessibility during storms, and ephemeral nature. A novel design, following on previous adaptive instrument designs, was created for this specific project. The design includes readily available materials (i.e. sourced from hardware stores), low cost, and allows for ease of replacement. Three instruments were designed following these design goals: a siphon sampler (water chemistry), sediment trap (suspended sediments), and a stage sensor (water level). These instruments were mounted to a t-post array in the stream channel. This installation approach, collectively named the “sed-chem gage”, was operated at each ephemeral arroyo for two consecutive field seasons. The instrument design approach, parts list, and results of operation are presented herein. This approach will be useful to scientists, water managers, and communities who need to evaluate water flow and water and sediment chemistry in a large, remote area where traditional techniques and methods may be cost prohibitive.

Arizona, Colorado, New Mexico, Utah↗
USGS1991

User's guide to the wetland creation/restoration data base, version 2

Wetland creation or restoration projects are frequently proposed as mitigation for unavoidable wetland losses, as components of wetland enhancement programs, and as tools to accomplish specific objectives such as waterfowl production or flood control. There is considerable controversy concerning the effectiveness of such projects as well as the most appropriate and efficient techniques to employ. The importance of the resource and the long time scales involved in fully evaluating a creation or restoration effort make it imperative to consider existing information as fully as possible in the development and evaluation of wetland creation or restoration proposals. To aid in the evaluation of wetland/creation efforts, the U.s. Fish and Wildlife Service (FWS), National Ecology Research Center, has developed the Wetland Creation/Restoration (WCR) Data Base. The data base is a highly indexed or keyworded bibliography of wetland creation or restoration articles. ("Articles" refers to any type of publication that deals specifically with wetland creation/restoration projects or studies.) The scope of the articles is international, although most of them are concerned with projects conducted in the United States. Information coded for each article includes author; citation; type of wetland and its location in terms of state, ecoregion, and FWS region; type of study undertaken; objectives in creating or restoring the wetland; actions performed to realize those objectives; length of time encompassed by the study; evaluation of results and responses to the wetland creation/restoration actions; and a listing of plant species significant to the project. A brief annotation summarizes the article and includes any significant additional information that may not be adequately reflected in the above described fields. Many of these articles describe only one or two components of a total wetland restoration effort. Planning a project that is designed to restore a wetland system (including at least some of its functions) is similar to constructing a picture from a number of puzzle pieces--missing pieces represent data gaps or information that is not available. Articles range from specific case studies, to overviews of restoration methods and techniques, to planning restoration projects and assessing programmatic and administrative backgrounds and interactions. In this data base, the term "restoration" is applied loosely to include rehabilitation of wetlands. It may refer to a number of situations or actions including, but not limited to: 1. breaching dikes or plugging drains; 2. water pollution clean-up; 3. conversion of eutrophic conditions; 4. wastewater treatment; 5. recolonization of previously disturbed or denuded areas; 6. amelioration of adverse conditions (erosion, wave, or wind action); 7. soil treatment --mulching, fertilization; 8. rerouting streams --may include construction of meander patterns; 9. monitoring natural vegetation; or 0. excluding grazers (geese, cattle) and monitoring results. This report describes the format and content of Version 2 of the WCR data base. Version 2 differs from the previous version described in SchnellerMcDonald et al. (1988): several fields have been dropped and condensed and new records have been added. Version 2 includes all records distributed with the earlier version and its updates. We recommend you replace any previous version with Version 2.

Book↗