Geology topics

Martyn J. Smith

Publications and source records attributed to Martyn J. Smith.

6 recordsLinked to original sources

USGS2017

StreamStats, version 4

Introduction StreamStats version 4, available at https://streamstats.usgs.gov , is a map-based web application that provides an assortment of analytical tools that are useful for water-resources planning and management, and engineering purposes. Developed by the U.S. Geological Survey (USGS), the primary purpose of StreamStats is to provide estimates of streamflow statistics for user-selected ungaged sites on streams and for USGS streamgages, which are locations where streamflow data are collected. Streamflow statistics, such as the 1-percent flood, the mean flow, and the 7-day 10-year low flow, are used by engineers, land managers, biologists, and many others to help guide decisions in their everyday work. For example, estimates of the 1-percent flood (which is exceeded, on average, once in 100 years and has a 1-percent chance of exceedance in any year) are used to create flood-plain maps that form the basis for setting insurance rates and land-use zoning. This and other streamflow statistics also are used for dam, bridge, and culvert design; water-supply planning and management; permitting of water withdrawals and wastewater and industrial discharges; hydropower facility design and regulation; and setting of minimum allowed streamflows to protect freshwater ecosystems. Streamflow statistics can be computed from available data at USGS streamgages depending on the type of data collected at the stations. Most often, however, streamflow statistics are needed at ungaged sites, where no streamflow data are available to determine the statistics.

Fact Sheet↗

USGS2015

Development of flood regressions and climate change scenarios to explore estimates of future peak flows

A new Web-based application, titled “Application of Flood Regressions and Climate Change Scenarios To Explore Estimates of Future Peak Flows”, has been developed by the U.S. Geological Survey, in cooperation with the New York State Department of Transportation, that allows a user to apply a set of regression equations to estimate the magnitude of future floods for any stream or river in New York State (exclusive of Long Island) and the Lake Champlain Basin in Vermont. The regression equations that are the basis of the current application were developed in previous investigations by the U.S. Geological Survey (USGS) and are described at the USGS StreamStats Web sites for New York ( http://water.usgs.gov/osw/streamstats/new_york.html ) and Vermont ( http://water.usgs.gov/osw/streamstats/Vermont.html ). These regression equations include several fixed landscape metrics that quantify aspects of watershed geomorphology, basin size, and land cover as well as a climate variable—either annual precipitation or annual runoff. The application uses predictions of future annual precipitation from five climate models and two future greenhouse gas emissions scenarios and provides results that are averaged over three future periods—2025 to 2049, 2050 to 2074, and 2075 to 2099. Results are presented in ensemble form as the mean, median, maximum, and minimum values among the five climate models for each greenhouse gas emissions scenario and period. These predictions of future annual precipitation are substituted into either the precipitation variable or a water balance equation for runoff to calculate potential future peak flows. This application is intended to be used only as an exploratory tool because (1) the regression equations on which the application is based have not been adequately tested outside the range of the current climate and (2) forecasting future precipitation with climate models and downscaling these results to a fine spatial resolution have a high degree of uncertainty. This report includes a discussion of the assumptions, uncertainties, and appropriate use of this exploratory application.

Open-File Report↗

USGS2015

Variations in water temperature and implications for trout populations in the Upper Schoharie Creek and West Kill, New York, USA

Water temperature is a key component of aquatic ecosystems because it plays a pivotal role in determining the suitability of stream and river habitat to most freshwater fish species. Continuous temperature loggers and airborne thermal infrared (TIR) remote sensing were used to assess temporal and spatial temperature patterns on the Upper Schoharie Creek and West Kill in the Catskill Mountains, New York, USA. Specific objectives were to characterize (1) contemporary thermal conditions, (2) temporal and spatial variations in stressful water temperatures, and (3) the availability of thermal refuges. In-stream loggers collected data from October 2010 to October 2012 and showed summer water temperatures exceeded the 1-day and 7-day thermal tolerance limits for trout survival at five of the seven study sites during both summers. Results of the 7 August 2012 TIR indicated there was little thermal refuge at the time of the flight. About 690,170 m 2 of water surface area were mapped on the Upper Schoharie, yet only 0.009% (59 m 2 ) was more than 1.0 °C below the median water surface temperature (BMT) at the thalweg and no areas were more than 2.0 °C BMT. On the West Kill, 79,098 m 2 were mapped and 0.085% (67 m 2 ) and 0.018% (14 m 2 ) were BMT by 1 and 2 °C, respectively. These results indicate that summer temperatures in the majority of the study area are stressful for trout and may adversely affect growth and survival. Validation studies are needed to confirm the expectation that resident trout are in poor condition or absent from the downstream portion of the study area during warm-water periods.

New York↗

USGS2011

Spatial patterns of mercury in macroinvertebrates and fishes from streams of contrasting forested landscapes in the eastern United States

Controls on mercury bioaccumulation in lotic ecosystems are not well understood. During 2007–2009, we studied mercury and stable isotope spatial patterns of macroinvertebrates and fishes from two medium-sized (<80 km 2 ) forested basins in contrasting settings. Samples were collected seasonally from multiple sites across the Fishing Brook basin (FBNY), in New York's Adirondack Mountains, and the McTier Creek basin (MCSC), in South Carolina's Coastal Plain. Mean methylmercury (MeHg) concentrations within macroinvertebrate feeding groups, and mean total mercury (THg) concentrations within most fish feeding groups were similar between the two regions. However, mean THg concentrations in game fish and forage fish, overall, were much lower in FBNY (1300 and 590 ng/g dw, respectively) than in MCSC (2300 and 780 ng/g dw, respectively), due to lower trophic positions of these groups from FBNY (means 3.3 and 2.7, respectively) than MCSC (means 3.7 and 3.3, respectively). Much larger spatial variation in topography and water chemistry across FBNY contributed to greater spatial variation in biotic Hg and positive correlations with dissolved MeHg and organic carbon in streamwater. Hydrologic transport distance (HTD) was negatively correlated with biotic Hg across FBNY, and was a better predictor than wetland density. The small range of landscape conditions across MCSC resulted in no consistent spatial patterns, and no discernable correspondence with local-scale environmental factors. This study demonstrates the importance of local-scale environmental factors to mercury bioaccumulation in topographically heterogeneous landscapes, and provides evidence that food-chain length can be an important predictor of broad-scale differences in Hg bioaccumulation among streams.

New York, South Carolina↗

USGS2011

Environmental settings of streams sampled for mercury in New York and South Carolina, 2005-09

This report summarizes the environmental settings of streams in New York and South Carolina, where the U.S. Geological Survey completed detailed investigations during 2005-09 into factors contributing to mercury bioaccumulation in top-predator fish and other stream organisms. Descriptions of location, land use/land cover, climate, precipitation, atmospheric deposition, hydrology, water temperature, and other characteristics are provided. Atmospheric deposition is the dominant mercury source in the studied basins where biota, sediment, soil, and water were sampled for mercury and for physical and chemical characteristics believed to be important in mercury methylation and transport.

New York, South Carolina↗

USGS2006

Magnitude and Frequency of Floods in New York

Techniques are presented for estimating the magnitude and frequency of flood discharges on rural, unregulated streams in New York, excluding Long Island. Peak-discharge-frequency data and basin characteristics from 388 streamflow-gaging stations in New York and adjacent states were used to develop multiple linear regression equations for flood discharges with recurrence intervals ranging from 1.25 to 500 years. A generalized least-squares (GLS) procedure was used to develop the regression equations. Separate sets of equations were developed for each of six hydrologic regions of New York; standard errors of prediction range from 14 to 43 percent. Statistically significant explanatory variables in the regression equations include drainage area, main-channel slope, percent basin storage, mean annual precipitation, percent forested area, a basin lag factor, a ratio of main-channel slope to basin slope, mean annual runoff, maximum snow depth, and percentage of basin above 1,200 feet. Drainage areas for the 388 sites used in the analyses ranged from 0.41 to 4,773 square miles. Methods of computing flood discharges from the regression equations differ, depending on whether the estimate is for a gaged or ungaged basin, and whether the basin crosses hydrologic-region or state boundaries. Examples of computations are included. Discharge-frequency estimates for an additional 122 streamflow-gaging stations with significant regulation or urbanization (including Long Island) are also included as at-site estimates. Basin characteristics, log-Pearson Type III statistics, and regression and weighted estimates of the discharge-frequency relations are tabulated for the streamflow-gaging stations used in the regression analyses. Sensitivity analyses showed that mean-annual precipitation, drainage area, mean annual runoff, and maximum snow depth are the variables to which computed discharges are most sensitive in the regression equations. Included with the report is a DVD that provides computation procedures and geographic information system spatial datasets to compute basin characteristics used in the regional regression equations and flood-frequency estimates at a specified location on a stream.

Scientific Investigations Report↗