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USGS2012

How well do the rosgen classification and associated "natural channel design" methods integrate and quantify fluvial processes and channel response?

Over the past 10 years the Rosgen classification system and its associated methods of "natural channel design" have become synonymous (to many without prior knowledge of the field) with the term "stream restoration" and the science of fluvial geomorphology. Since the mid 1990s, this classification approach has become widely, and perhaps dominantly adopted by governmental agencies, particularly those funding restoration projects. For example, in a request for proposals for the restoration of Trout Creek in Montana, the Natural Resources Conservation Service required "experience in the use and application of a stream classification system and its implementation." Similarly, classification systems have been used in evaluation guides for riparian areas and U.S. Forest Service management plans. Most notably, many highly trained geomorphologists and hydraulic engineers are often held suspect, or even thought incorrect, if their approach does not include reference to or application of a classification system. This, combined with the para-professional training provided by some involved in "natural channel design" empower individuals and groups with limited backgrounds in stream and watershed sciences to engineer wholesale re-patterning of stream reaches using 50-year old technology that was never intended for engineering design. At Level I, the Rosgen classification system consists of eight or nine major stream types, based on hydraulic-geometry relations and four other measures of channel shape to distinguish the dimensions of alluvial stream channels as a function of the bankfull stage. Six classes of the particle size of the boundary sediments are used to further sub-divide each of the major stream types, resulting in 48 or 54 stream types. Aside from the difficulty in identifying bankfull stage, particularly in incising channels, and the issue of sampling from two distinct populations (beds and banks) to classify the boundary sediments, the classification provides a consistent and reproducible means for practitioners to describe channel morphology although difficulties have been encountered in lower-gradient stream systems. Use of the scheme to communicate between users or as a conceptual model, however, has not justified its use for engineering design or for predicting river behavior; its use for designing mitigation projects, therefore, seems beyond its technical scope. Copyright ASCE 2005.

Conference Paper↗

USGS2011

Biomarker chemistry and flux quantification methods for natural petroleum seeps and produced oils, offshore southern California

Sustained, natural oil seepage from the seafloor is common off southern California, and is of great interest to resource managers, who are tasked with distinguishing natural from anthropogenic oil sources. The major purpose of this study was to build upon the work previously funded by the Bureau of Ocean Energy Management (BOEM) and the U.S. Geological Survey (USGS) that has refined the oil-fingerprinting process to enable differentiation of the highly similar Monterey Formation oils from Outer Continental Shelf (OCS) production and adjacent natural seeps. In these initial studies, biomarker and stable carbon isotope ratios were used to infer the age, lithology, organic-matter input, and depositional environment of the source rocks for 388 samples of produced crude oil, seep oil, and tarballs mainly from coastal California. The analysis resulted in a predictive model of oil source families that could be applied to samples of unknown origin.

California↗

USGS2017

Review of dynamic optimization methods in renewable natural resource management

In recent years, the applications of dynamic optimization procedures in natural resource management have proliferated. A systematic review of these applications is given in terms of a number of optimization methodologies and natural resource systems. Optimization methods are characterized by (1) the mathematical model used to describe a natural resource system, (2) a set of feasible strategies available to the resource manager, and (3) an objective functional by which to measure benefits and costs of strategies. A formal statement of the control problem is used to describe six approaches to optimal utilization of renewable natural resources: variational mathematics, specifically Pontryagin's Maximum Principle; dynamic programming; linear programming; nonlinear programming; simulation-optimization; and classical procedures. Solution methodologies are illustrated for each of these approaches, and examples from the ecological and natural resource literature are described for various subject matter areas. Applications are highlighted in terms of model structures, objective functionals, and system constraints. To the extent possible, optimal management patterns are characterized. Finally, the applicability of the methods to renewable natural resource systems are compared in terms of system complexity, system size, and precision of the optimal solutions. Recommendations are made concerning the appropriate methods for certain kinds of biological resource problems.

Natural Resource Modeling↗

USGS2009

An interpolation method for stream habitat assessments

Interpolation of stream habitat can be very useful for habitat assessment. Using a small number of habitat samples to predict the habitat of larger areas can reduce time and labor costs as long as it provides accurate estimates of habitat. The spatial correlation of stream habitat variables such as substrate and depth improves the accuracy of interpolated data. Several geographical information system interpolation methods (natural neighbor, inverse distance weighted, ordinary kriging, spline, and universal kriging) were used to predict substrate and depth within a 210.7-m 2 section of a second-order stream based on 2.5% and 5.0% sampling of the total area. Depth and substrate were recorded for the entire study site and compared with the interpolated values to determine the accuracy of the predictions. In all instances, the 5% interpolations were more accurate for both depth and substrate than the 2.5% interpolations, which achieved accuracies up to 95% and 92%, respectively. Interpolations of depth based on 2.5% sampling attained accuracies of 49–92%, whereas those based on 5% percent sampling attained accuracies of 57–95%. Natural neighbor interpolation was more accurate than that using the inverse distance weighted, ordinary kriging, spline, and universal kriging approaches. Our findings demonstrate the effective use of minimal amounts of small-scale data for the interpolation of habitat over large areas of a stream channel. Use of this method will provide time and cost savings in the assessment of large sections of rivers as well as functional maps to aid the habitat-based management of aquatic species.

West Virginia↗

USGS2011

Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation

Collecting and preserving undamaged core samples containing gas hydrates from depth is difficult because of the pressure and temperature changes encountered upon retrieval. Hydrate-bearing core samples were collected at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well in February 2007. Coring was performed while using a custom oil-based drilling mud, and the cores were retrieved by a wireline. The samples were characterized and subsampled at the surface under ambient winter arctic conditions. Samples thought to be hydrate bearing were preserved either by immersion in liquid nitrogen (LN), or by storage under methane pressure at ambient arctic conditions, and later depressurized and immersed in LN. Eleven core samples from hydrate-bearing zones were scanned using x-ray computed tomography to examine core structure and homogeneity. Features observed include radial fractures, spalling-type fractures, and reduced density near the periphery. These features were induced during sample collection, handling, and preservation. Isotopic analysis of the methane from hydrate in an initially LN-preserved core and a pressure-preserved core indicate that secondary hydrate formation occurred throughout the pressurized core, whereas none occurred in the LN-preserved core, however no hydrate was found near the periphery of the LN-preserved core. To replicate some aspects of the preservation methods, natural and laboratory-made saturated porous media samples were frozen in a variety of ways, with radial fractures observed in some LN-frozen sands, and needle-like ice crystals forming in slowly frozen clay-rich sediments. Suggestions for hydrate-bearing core preservation are presented.

Alaska↗

USGS1978

Method of estimating natural recharge to the Edwards Aquifer in the San Antonio area, Texas

The method of estimating annual recharge is based on data collected from a network of stream-gaging stations and on assumptions related to applying the runoff characteristics from gaged areas to ungaged areas. The basic approach is a water-balance equation, in which recharge within a stream basin is the difference between measured streamflow above and below the infiltration area of the aquifer plus the estimated runoff in the zone that includes the infiltration area. Recharge in the Medina River basin also includes seepage losses from Medina Lake and Diversion Reservoir. The principal errors in the estimates of annual recharge are related to errors in estimating runoff in ungaged areas, which represent about 30 percent of the infiltration area. The estimated long-term average annual recharge in each basin, however, is probably representative of the actual recharge because the averaging procedure tends to cancel out the major errors.

Texas↗

USGS2026

A method to implement natural flow regimes for regulated rivers

Rivers throughout the world have been dammed for flood control, irrigation, hydropower, and water storage for centuries. Dams service the economic and development needs of societies, but degrade the ecology of rivers. To conserve diminishing aquatic species and their habitats, methods are needed to help managers implement flow releases with timescales and patterns that are relevant to aquatic species and physical processes. We present a method to synchronize flow releases from dams with local hydrology, while ensuring constraints of flood control and water allocations are met. We demonstrate an optimization technique that scales flows of a proximal unregulated river and results in discharges that are synchronized with natural hydrologic patterns. Importantly, our method preserves operational and regulatory requirements such as water allocation volumes and flood control thresholds. This technique can be used at various timescales, and can incorporate many system-specific constraints. We selected the Trinity River, California as an example, and scale flows according to a proximal gage on the Salmon River in California. We evaluate our technique using an array of flow regime metrics from the literature, and our method produced hydrographs with greater flow variation throughout a larger portion of the water year than current management strategies. These hydrographs yielded flow metrics more similar to those from unimpaired flow patterns, including those measuring within and among year flow variability. The Real Time Management framework is a new tool that can be implemented to improve the health of rivers and the aquatic species that depend upon them.

California↗

USGS2021

Isotopic composition of natural and synthetic chlorate (δ18O, Δ17O, δ37Cl, 36Cl/Cl): Methods and initial results

Natural chlorate (ClO 3 − ) is widely distributed in terrestrial and extraterrestrial environments. To improve understanding of the origins and distribution of ClO 3 − , we developed and tested methods to determine the multi-dimensional isotopic compositions (δ 18 O, Δ 17 O, δ 37 Cl, 36 Cl/Cl) of ClO 3 − and then applied the methods to samples of natural nitrate-rich caliche-type salt deposits in the Atacama Desert, Chile, and Death Valley, USA. Tests with reagents and artificial mixed samples indicate stable-isotope ratios were minimally affected by the purification processes. Chlorate extracted from Atacama samples had δ 18 O = +7.0 to +11.1‰, Δ 17 O = +5.7 to +6.4‰, δ 37 Cl = −1.4 to +1.3‰, and 36 Cl/Cl = 48 × 10 −15 to 104 × 10 −15 . Chlorate from Death Valley samples had δ 18 O = −6.9 to +1.6‰, Δ 17 O = +0.4 to +2.6‰, δ 37 Cl = +0.8 to +1.0‰, and 36 Cl/Cl = 14 × 10 −15 to 44 × 10 −15 . Positive Δ 17 O values of natural ClO 3 − indicate that its production involved reaction with O 3 , while its Cl isotopic composition is consistent with a tropospheric or near-surface source of Cl. The Δ 17 O and δ 18 O values of natural ClO 3 − are positively correlated, as are those of ClO 4 − and NO 3 − from the same localities, possibly indicating variation in the relative contributions of O 3 as a source of O in the formation of the oxyanions. Additional isotopic analyses of ClO 3 − could provide stronger constraints on its production mechanisms and/or post-formational alterations, with applications for environmental forensics, global biogeochemical cycling of Cl, and the origins of oxyanions detected on Mars.

Chemosphere↗

USGS2012

A new method of calculating electrical conductivity with applications to natural waters

A new method is presented for calculating the electrical conductivity of natural waters that is accurate over a large range of effective ionic strength (0.0004–0.7 mol kg −1 ), temperature (0–95 °C), pH (1–10), and conductivity (30–70,000 μS cm −1 ). The method incorporates a reliable set of equations to calculate the ionic molal conductivities of cations and anions (H + , Li + , Na + , K + , Cs + , NH 4 + , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , F − , Cl − , Br − , SO 4 2- , HCO 3 - , CO 3 2- , NO 3 - , and OH − ), environmentally important trace metals (Al 3+ , Cu 2+ , Fe 2+ , Fe 3+ , Mn 2+ , and Zn 2+ ), and ion pairs (HSO 4 - , NaSO 4 - , NaCO 3 - , and ). These equations are based on new electrical conductivity measurements for electrolytes found in a wide range of natural waters. In addition, the method is coupled to a geochemical speciation model that is used to calculate the speciated concentrations required for accurate conductivity calculations. The method was thoroughly tested by calculating the conductivities of 1593 natural water samples and the mean difference between the calculated and measured conductivities was −0.7 ± 5%. Many of the samples tested were selected to determine the limits of the method and include acid mine waters, geothermal waters, seawater, dilute mountain waters, and river water impacted by municipal waste water. Transport numbers were calculated and H + , Na + , Ca 2+ , Mg 2+ , NH 4 + , K + , Cl − , SO 4 2- , HCO 3 - , CP 3 2- , F − , Al 3+ , Fe 2+ , NO 3 - , and substantially contributed (>10%) to the conductivity of at least one of the samples. Conductivity imbalance in conjunction with charge imbalance can be used to identify whether a cation or an anion measurement is likely in error, thereby providing an additional quality assurance/quality control constraint on water analyses.

Geochimica et Cosmochimica Acta↗

USGS2002

Concentration method for the spectrochemical determination of seventeen minor elements in natural water

A method for the quantitative spectrochemical determination of microgram amounts of 17 minor elements in water is given. The chelating reagents 8-quinolinol, tannic acid, and thionalide are utilized to concentrate traces (1 to 500 μ g.) of aluminum, cobalt, chromium, copper, iron, gallium, germanium, manganese, nickel, titanium, vanadium, bismuth, lead, molybdenum, cadmium, zinc, and beryllium. Indium is added as a buffer, and palladium is used as an internal standard. The ashed oxides of these 17 metals are subsequently subjected to direct current arcing conditions during spectrum analysis. The method can be used to analyze waters with dissolved solids ranging from less than 100 to more than 100,000 p.p.m. There is no limiting concentration range for the determination of the heavy metals since any volume of sample can be used that will contain a heavy metal concentration within the analytical range of the method. Both the chemical and spectrographic procedures are described, and precision and accuracy data are given.

Analytical Chemistry↗

USGS2007

Comparison of peak-flow estimation methods for small drainage basins in Maine

Understanding the accuracy of commonly used methods for estimating peak streamflows is important because the designs of bridges, culverts, and other river structures are based on these flows. Different methods for estimating peak streamflows were analyzed for small drainage basins in Maine. For the smallest basins, with drainage areas of 0.2 to 1.0 square mile, nine peak streamflows from actual rainfall events at four crest-stage gaging stations were modeled by the Rational Method and the Natural Resource Conservation Service TR-20 method and compared to observed peak flows. The Rational Method had a root mean square error (RMSE) of -69.7 to 230 percent (which means that approximately two thirds of the modeled flows were within -69.7 to 230 percent of the observed flows). The TR-20 method had an RMSE of -98.0 to 5,010 percent. Both the Rational Method and TR-20 underestimated the observed flows in most cases. For small basins, with drainage areas of 1.0 to 10 square miles, modeled peak flows were compared to observed statistical peak flows with return periods of 2, 50, and 100 years for 17 streams in Maine and adjoining parts of New Hampshire. Peak flows were modeled by the Rational Method, the Natural Resources Conservation Service TR-20 method, U.S. Geological Survey regression equations, and the Probabilistic Rational Method. The regression equations were the most accurate method of computing peak flows in Maine for streams with drainage areas of 1.0 to 10 square miles with an RMSE of -34.3 to 52.2 percent for 50-year peak flows. The Probabilistic Rational Method was the next most accurate method (-38.5 to 62.6 percent). The Rational Method (-56.1 to 128 percent) and particularly the TR-20 method (-76.4 to 323 percent) had much larger errors. Both the TR-20 and regression methods had similar numbers of underpredictions and overpredictions. The Rational Method overpredicted most peak flows and the Probabilistic Rational Method tended to overpredict peak flows from the smaller (less than 5 square miles) drainage basins and underpredict peak flows from larger drainage basins. The results of this study are consistent with the most comprehensive analysis of observed and modeled peak streamflows in the United States, which analyzed statistical peak flows from 70 drainage basins in the Midwest and the Northwest.

Maine↗

USGS2011

Electrical conductivity of electrolytes applicable to natural waters from 0 to 100 degrees C

The electrical conductivities of 34 electrolyte solutions found in natural waters ranging from (10 -4 to 1) molkg -1 in concentration and from (5 to 90) °C have been determined. High-quality electrical conductivity data for numerous electrolytes exist in the scientific literature, but the data do not span the concentration or temperature ranges of many electrolytes in natural waters. Methods for calculating the electrical conductivities of natural waters have incorporated these data from the literature, and as a result these methods cannot be used to reliably calculate the electrical conductivity over a large enough range of temperature and concentration. For the single-electrolyte solutions, empirical equations were developed that relate electrical conductivity to temperature and molality. For the 942 molar conductivity determinations for single electrolytes from this study, the mean relative difference between the calculated and measured values was 0.1 %. The calculated molar conductivity was compared to literature data, and the mean relative difference for 1978 measurements was 0.2 %. These data provide an improved basis for calculating electrical conductivity for most natural waters.

Journal of Chemical and Engineering Data↗

USGS1984

Areal lithologic changes in bedrock aquifers in southeastern Minnesota as determined from natural-gamma borehole logs methods

Sedimentary rocks of Paleozoic age in the Hollandale embayment in southeastern Minnesota are as much as 2,000 feet thick and, with the underlying Hinckley sandstone of Proterozoic age, comprise the following five layered aquifers (beginning with the oldest): the Mount Simon-Hinckley, Ironton-Galesville, Prairie du Chien-Jordan, St. Peter and Upper Carbonate. Many of the Paleozoic formations show transitional facies changes from a deep marine depositional environment in the middle of the embayment to a near shore environment along the periphery. Borehole natural-gamma logs were collected to investigate the effects of regional lithologic changes on the hydrology of the Ironton-Galesville, Prairie du Chien-Jordan and St. Peter aquifers. Interpretation of natural-gamma logs shows that a fine-grained sandstone at the base of the Galesville sandstone (basal part of the Ironton-Galesville aquifer) thickens toward the central part of the embayment, which may account for the decrease in hydraulic conductivity of the Ironton-Galesville aquifer in that direction. The Jordan sandstone, which underlies the Prairie du Chien Group, consists of three members in southeastern Minnesota: the basal Norwalk member, a silty, fine-grained sandstone; the middle Van Oser member, a coarse- to medium-grained quartzose sandstone; and the upper Sunset Point member, a clayey dolomitic sandstone. The Norwalk and Van Oser members were identified by interpretation of natural-gamma logs. Hydraulic conductivity of the Prairie du Chien-Jordan aquifer generally is highest in the Twin City basin (50 feet per day) where the Van Oser is the predominant member; it is lowest to the east and southeast (25 feet per day) where the Norwalk member thickens. Interpretation of natural-gamma logs indicates that the shaley and silty sandstones that comprise the basal St. Peter confining bed, which separates the St. Peter and Prairie du Chien aquifers, are as much as 80 feet thick in the Twin City basin, but are absent in the southern part of the embayment. Differences in potentiometric head across the basal St. Peter are about 30 feet in the Twin City basin where the confining bed is present but only 5 to 10 feet to the south where the confining bed is absent and where the St. Peter aquifer directly overlies the Prairie du Chien-Jordan aquifer.

Minnesota↗

USGS2003

Analytical method for optimal source reduction with monitored natural attenuation in contaminated aquifers

A method is developed for optimizing monitored natural attenuation (MNA) and the reduction in the aqueous source zone concentration (??C) required to meet a site-specific regulatory target concentration. The mathematical model consists of two one-dimensional equations of mass balance for the aqueous phase contaminant, to coincide with up to two distinct zones of transformation, and appropriate boundary and intermediate conditions. The solution is written in terms of zone-dependent Peclet and Damko??hler numbers. The model is illustrated at a chlorinated solvent site where MNA was implemented following source treatment using in-situ chemical oxidation. The results demonstrate that by not taking into account a variable natural attenuation capacity (NAC), a lower target ??C is predicted, resulting in unnecessary source concentration reduction and cost with little benefit to achieving site-specific remediation goals.

Conference Paper↗

USGS2021

Coalescent methods reconstruct contributions of natural colonization and stocking to origins of Michigan inland Cisco (Coregonus artedi)

Fish population structure in previously glaciated regions is often influenced by natural colonization processes and human-mediated dispersal, including fish stocking. Endemic populations are of conservation interest because they may contain rare and unique genetic variation. While coregonines are native to certain Michigan inland lakes, some were stocked with fish from Great Lakes sources, calling into question the origin of extant populations. While most stocking targeted lake whitefish ( Coregonus clupeaformis ), cisco ( C. artedi ) were also stocked from the Great Lakes to inland waterbodies. We used population genetic data (microsatellite genotypes and mitochondrial (mt)DNA sequences), coalescent modeling, and approximate Bayesian computation to investigate the origins of 12 inland Michigan cisco populations. The spatial distribution of mtDNA haplotypes suggests Michigan is an introgression zone for two ancestral cisco lineages associated with separate glacial refugia. Low levels of genetic diversity and high levels of genetic divergence were observed for populations located well inland of the Great Lakes relative to populations occupying waterbodies near the Great Lakes. Estimates of recent Great Lakes gene flow ranged from 27 to 48% for populations near the Great Lakes shoreline but were substantially lower (under 8%) for populations further inland. Inland lakes with elevated recent gene flow estimates may have been recipients of stocked coregonine fry, including cisco. Low levels of genetic diversity paired with a high likelihood of endemism as indicated by strong genetic divergence and low Great Lakes population inputs suggest the analyzed cisco populations occupying southern Michigan kettle lakes are of elevated conservation interest.

Michigan↗

USGS2018

A method to value nature-related webcam viewing: The value of virtual use with application to brown bear webcam viewing

There are an estimated 16,000 nature related remote web cameras that provide users around the world with an opportunity to view wildlife. Because there is no monetary price to view the webcams, we utilise variations in the viewers’ opportunity cost of time to estimate consumer surplus. We apply this model to a large sample ( n = 2649) of the more than 10 million viewers of Alaska's Katmai National Park and Preserve brown bear webcams. The resulting consumer surplus is around \$11 per hour of viewing. When applied to the 2.42 million viewer hours, this yields a benefit of \$27 million annually. Since there are limits on the number of visitors as well as high costs of visiting this remote site, the aggregate webcam viewing value is more than twice the aggregate on-site viewing value. With minimal survey data required to apply this model, we believe it has broad applicability to other nature-related webcams around the world.

Journal of Environmental Economics and Policy↗

USGS2024

Studies to assess natural resource recovery and evaluate monitoring methods for restored bottomland hardwood forests

The Natural Resource Damage Assessment and Restoration process assesses natural resource injury due to oil or chemical spills and calculates the damages to compensate the public for those injuries. Ecological restoration provides a means for recovering resources injured or lost due to contamination from oil or chemical spills by restoring the injured site after remediation, or acquiring or reconstructing equivalent resources off site to replace those lost due to the spill. In the case of restored forests, once restoration is implemented, monitoring of forest ecology helps keep recovery on track, with the maturation of forest vegetation, recovered soil conditions, and development of microbial, fungal, and faunal communities, necessary for ecologically functioning forests. This series of papers focuses on applying methods for monitoring restoration progress in forest vegetation and soils, and amphibian, avian, and mammalian communities, assessing strengths and weaknesses of different methods, and evaluating levels of effort needed to obtain accurate indications of forest ecological condition.

Integrated Environmental Assessment and Management↗

USGS1989

Atlantic salmon brood stock management and breeding handbook

Anadromus runs of Atlantic salmon have been restored to the Connecticut, Merrimack, Pawcatuck, Penobscot, and St. Croix rivers in New England by the stocking of more than 8 million smolts since 1948. Fish-breeding methods have been developed that minimize inbreeding and domestication and enhance natural selection. Methods are available to advance the maturation of brood stock, control the sex of production lots and store gametes. Current hatchery practices emphasize the use of sea-run brood stock trapped upon return to the rivers and a limited number of captive brood stock and rejuvenated kelts. Fish are allowed to mature naturally, after which they are spawned and incubated artificially. Generally, 1-year smolts are produced, and excess fish are stocked as fry in headwater streams. Smolts are stocked during periods of rising water in spring. Self-release pools are planned that enable smolts to choose the emigration time. Culturists keep good records that permit evaluation of the performance of strains and the effects of breeding practices. As Atlantic salmon populations expand, culturists must use sound breeding methods that enhance biotic potential while maintaining genetic diversity and protecting unique gene pools.

Biological Report↗