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USGS2002

Analysis of the magnitude and frequency of the 4-day annual low flow and regression equations for estimating the 4-day, 3-year low-flow frequency at ungaged sites on unregulated streams in New Mexico

Two regression equations were developed for estimating the 4-day, 3-year (4Q3) low-flow frequency at ungaged sites on unregulated streams in New Mexico. The first, a statewide equation for estimating the 4Q3 low-flow frequency from drainage area and average basin mean winter precipitation, was developed from the data for 50 streamflow-gaging stations that had non-zero 4Q3 low-flow frequency. The 4Q3 low-flow frequency for the 50 gaging stations ranged from 0.08 to 18.7 cubic feet per second. For this statewide equation, the average standard error of estimate was 126 percent and the coefficient of determination was 0.48. The second, an equation for estimating the 4Q3 low-flowfrequency in mountainous regions from drainage area, average basin mean winter precipitation, and average basin slope, was developed from the data for 40 gaging stations located above 7,500 feet in elevation. For this regression equation, the average standard error of estimate was 94 percent and the coefficient of determination was 0.66. A U.S. Geological Survey computer-program interface for a geographical information system (GIS), called the GISWeasel,was used to determine basin and climatic characteristics for 84 gaging stations that were not affected by regulation. Mean monthly precipitation estimates from 1961 to 1990 were used in the GIS Weasel to compute the climatic characteristics of average basin winter precipitation and annual mean precipitation. The U.S. Geological Survey National Elevation Dataset, which currently consists of the 7.5-minute, 30-meter digital elevation model for each State, was used in the GISWeasel to compute the basin characteristics of drainage area, average basin slope, average basin elevation, and average basin aspect. Basin and climatic characteristics that were statistically significant in the regression equation with the 4Q3 lowflow frequency were drainage area, which ranged from 1.62 to 5,900 square miles; average basin mean winter precipitation, which ranged from 3.89 to 19.42 inches; and average basin slope, which ranged from 0.166 to 0.517 percent.

Water-Resources Investigations Report↗

USGS2013

Genomic analysis of avian influenza viruses from waterfowl in Western Alaska, USA

The Yukon-Kuskokwim Delta (Y-K Delta) in western Alaska is an immense and important breeding ground for waterfowl. Migratory birds from the Pacific Americas, Central Pacific, and East Asian-Australasian flyways converge in this region, providing opportunities for intermixing of North American- and Eurasian-origin hosts and infectious agents, such as avian influenza virus (AIV). We characterized the genomes of 90 low pathogenic (LP) AIV isolates from 11 species of waterfowl sampled on the Y-K Delta between 2006 and 2009 as part of an interagency surveillance program for the detection of the H5N1 highly pathogenic (HP) strain of AIV. We found evidence for subtype and genetic differences between viruses from swans and geese, dabbling ducks, and sea ducks. At least one gene segment in 39% of all isolates was Eurasian in origin. Target species (those ranked as having a relatively high potential to introduce HP H5N1 AIV to North America) were no more likely than nontarget species to carry viruses with genes of Eurasian origin. These findings provide evidence that the frequency at which viral gene segments of Eurasian origin are detected does not result from a strong species effect, but rather we suspect it is linked to the geographic location of the Y-K Delta in western Alaska where flyways from different continents overlap. This study provides support for retaining the Y-K Delta as a high priority region for the surveillance of Asian avian pathogens such as HP H5N1 AIV.

Alaska↗

USGS2010

Simulation of Runoff and Reservoir Inflow for Use in a Flood-Analysis Model for the Delaware River, Pennsylvania, New Jersey, and New York, 2004-2006

A model was developed to simulate inflow to reservoirs and watershed runoff to streams during three high-flow events between September 2004 and June 2006 for the main-stem subbasin of the Delaware River draining to Trenton, N.J. The model software is a modified version of the U.S. Geological Survey (USGS) Precipitation-Runoff Modeling System (PRMS), a modular, physically based, distributed-parameter modeling system developed to evaluate the impacts of various combinations of precipitation, climate, and land use on surface-water runoff and general basin hydrology. The PRMS model simulates time periods associated with main-stem flooding that occurred in September 2004, April 2005, and June 2006 and uses both daily and hourly time steps. Output from the PRMS model was formatted for use as inflows to a separately documented reservoir and riverrouting model, the HEC-ResSim model, developed by the U.S. Army Corps of Engineers Hydrologic Engineering Center to evaluate flooding. The models were integrated through a graphical user interface. The study area is the 6,780 square-mile watershed of the Delaware River in the states of Pennsylvania, New Jersey, and New York that drains to Trenton, N.J. A geospatial database was created for use with a geographic information system to assist model discretization, determine land-surface characterization, and estimate model parameters. The USGS National Elevation Dataset at 100-meter resolution, a Digital Elevation Model (DEM), was used for model discretization into streams and hydrologic response units. In addition, geospatial processing was used to estimate initial model parameters from the DEM and other data layers, including land use. The model discretization represents the study area using 869 hydrologic response units and 452 stream segments. The model climate data for point stations were obtained from multiple sources. These sources included daily data for 22 National Weather Service (NWS) Cooperative Climate Station network stations, hourly data for 15 stations from the National Climatic Data Center, hourly data for 1 station from the NWS Middle Atlantic River Forecast Center records, and daily and hourly data for 7 stations operated by the New York City Department of Environmental Protection. The NWS Multisensor Precipitation Estimate data set for 2001-2007 was used for computing daily precipitation for the model and for computing hourly precipitation for storm simulation periods. Calibration of the PRMS model included regression and optimization algorithms, as well as manual adjustments of model parameters. The general goal of the calibration procedure was to minimize the difference between discharge measured at USGS streamgages and the corresponding discharge simulated by the model. Daily streamflow data from 35 USGS streamgages were used in model calibration. The streamflow data represent areas draining from 20.2 to 6,780 square miles. The PRMS model simulates reservoir inflow and watershed runoff for use as input into HECResSim for the purpose of evaluating and comparing the effects of different watershed conditions on main-stem flooding in the Delaware River watershed draining to Trenton, N.J. The PRMS model is useful as a planning tool to simulate the effects of land-use changes and different antecedent conditions on local runoff and reservoir inflow and, as input to the HEC-ResSim model, on flood flows in the main stem of the Delaware River.

Open-File Report↗

USGS2001

Raster images of geologic maps of Middle Proterozoic Belt strata in parts of Benewah, Bonner, Kootenai and Shoshone Counties, Idaho and Lincoln, Mineral and Sanders Counties, Montana

Geologic maps of the western part of the Belt Basin of western Montana and northern Idaho were converted into digital raster (TIFF image) format to facilitate their manipulation in geographic information systems. The 85-mile x 100-mile map area mostly contains rocks belonging to the lower and middle Belt Supergroup. The area is of interest as these Middle Proterozoic strata contain vein-type lead-zinc-silver deposits in the Coeur d?Alene Mining District in the St. Regis and Revett formations and strata-bound copper-silver deposits, such as the Troy mine, within the Revett Formation. The Prichard Formation is also prospective for strata-bound lead-zinc deposits because equivalent Belt strata in southern British Columbia, Canada host the Sullivan lead-zinc deposit. Map data converted to digital images include 13 geological maps at scales ranging from 1:48,000 to 1:12,000. Geologic map images produced from these maps by color scanning were registered to grid tick coverages in a Universal Transverse Mercator (North American Datum of 1927, zone 11) projection using ArcView Image Analysis. Geo-registering errors vary from 10 ft to 114 ft.

Idaho, Montana↗

USGS2003

Genetic variation among interconnected populations of Catostomus occidentalis: Implications for distinguishing impacts of contaminants from biogeographical structuring

Exposure to contaminants can affect survivorship, recruitment, reproductive success, mutation rates and migration, and may play a significant role in the partitioning of genetic variation among exposed and nonexposed populations. However, the application of molecular population genetic data to evaluate such influences has been uncommon and often flawed. We tested whether patterns of genetic variation among native fish populations (Sacramento sucker, Catostomus occidentalis) in the Central Valley of California were consistent with long-term pesticide exposure history, or primarily with expectations based on biogeography. Field sampling was designed to rigorously test for both geographical and contamination influences. Fine-scale structure of these interconnected populations was detected with both amplified fragment length polymorphisms (AFLP) and microsatellite markers, and patterns of variation elucidated by the two marker systems were highly concordant. Analyses indicated that biogeographical hypotheses described the data set better than hypotheses relating to common historical pesticide exposure. Downstream populations had higher genetic diversity than upstream populations, regardless of exposure history, and genetic distances showed that populations from the same river system tended to cluster together. Relatedness among populations reflected primarily directions of gene flow, rather than convergence among contaminant-exposed populations. Watershed geography accounted for significant partitioning of genetic variation among populations, whereas contaminant exposure history did not. Genetic patterns indicating contaminant-induced selection, increased mutation rates or recent bottlenecks were weak or absent. We stress the importance of testing contaminant-induced genetic change hypotheses within a biogeographical context. Strategic application of molecular markers for analysis of fine-scale structure, and for evaluating contaminant impacts on gene pools, is discussed.

Molecular Ecology↗

USGS2019

Intensity and impact of the New York Railroad superstorm of May 1921

Analysis is made of low‐latitude ground‐based magnetometer data recording the magnetic superstorm of May 1921. By inference, the storm was driven by a series of interplanetary coronal mass ejections, one of which produced a maximum pressure on the magnetopause of ~64.5 nPa, sufficient to compress the subsolar magnetopause radius to ~5.3 Earth radii. Over the course of the storm, low‐latitude geomagnetic disturbance exhibited extreme local time (longitude) asymmetry that can be attributed to substorm disturbance extending to low latitudes. The storm attained an estimated maximum − Dst on 15 May of 907 ± 132 nT, an intensity comparable to that of the Carrington event of 1859. The May 1921 storm brought spectacular aurorae to the nighttime sky. It also interfered with and damaged telephone and telegraph systems associated with railroad systems in New York City and State. These later effects were due to a combination of three factors: the localized details of geomagnetic vector disturbance, the geographic expression of the Earth's surface impedance tensor, and the configurations and physical parameters of the electrical networks of the day.

New York↗

USGS2010

Assessment of arsenic concentrations in domestic well water, by town, in Maine 2005-09

Prior studies have established that approximately 10 percent of domestic wells in Maine have arsenic levels greater than the U.S. Environmental Protection Agency maximum contaminant limit (10 micrograms per liter (ug/L)). Of even greater concern are multiple discoveries of wells with very high arsenic levels (> 500 ug/L) in several areas of the State. A study was initiated to assist the Maine Center for Disease Control and Prevention (ME-CDC) in developing a better understanding of the statewide spatial occurrence of wells with elevated arsenic levels at the individual town level, identify areas of the State that should be targeted for increased efforts to promote well-water testing, and generate data for potential use in predicting areas of the State likely to have very high levels of arsenic. The State's Health and Environmental and Testing Laboratory (HETL) annually analyzes samples from thousands of domestic wells for arsenic. Results of arsenic analyses of domestic well water submitted to the HETL from 2005 to 2009 were screened and organized, by town, in order to summarize the results for all towns with samples submitted to the HETL. In order to preserve the privacy of well owners, the screening and organization of samples was conducted in the offices of the ME-CDC, following applicable Maine and United States laws, rules, and privacy policies. After screening, the database contained samples from 531 towns in Maine and from 11,111 individual wells. Of those towns, 385 had samples from 5 or more individual wells, 174 towns had samples from 20 or more individual wells, and 49 towns had samples from 60 or more wells. These samples, because they were submitted by homeowners and were not part of a random sample, may not be representative of all wells in a given area. The minimum, maximum, and median arsenic values for the towns with five or more samples were calculated, and the maximum and median values were mapped for the State. The percentages of samples exceeding 10, 50, 100, and 500 ug/L were calculated for the 174 towns with 20 or more sampled wells, and statewide maps were prepared for each of these categories. More than 25 percent of the sampled wells in 44 towns exceeded 10 ug/L. Many fewer towns had wells with samples that exceeded the 50, 100, or 500 ug/L categories. For 19 towns, more than 10 percent of the sampled wells had arsenic concentrations that exceeded 50 ug/L, and in 45 towns, 1 percent or more exceeded 100 ug/L. Of these, Surry in Hancock County had 120 wells tested, and 23 percent of those wells had arsenic concentrations that exceeded 100 ug/L, which is a much higher rate than for other towns. In only four towns (Danforth in Washington County, Surry and Blue Hill in Hancock County, and Woolwich in Sagadahoc County), 1 percent or more of the sampled wells had arsenic concentrations greater than 500 ug/L during 2005-09. The distribution of high arsenic concentrations in wells follows some geographic patterns, which are generally geologically controlled. There are clusters or belts of towns with high arsenic concentrations (> 50 ug/L), such as in southern coastal areas, the Kennebec County area, and towns along the central coastal part of Maine. In contrast, there are areas of the State with low arsenic concentrations, such as the northernmost towns, as well as towns in the western and west-central areas. There appear to be three distinct large-scale areas of high concentrations of arsenic in groundwater-one in southern coastal areas, one in central Kennebec County, and one in the town of Ellsworth (Hancock County) and the surrounding areas. In addition, several smaller clusters of isolated high concentrations of arsenic in groundwater exist. Earlier testing has identified other clusters of very high arsenic concentrations in groundwater in the towns of Northport, Buxton/Hollis, and Waldoboro, but those samples were collected before 2005 and did not factor in this analysis.

Scientific Investigations Report↗

USGS2007

Invasive species management and research using GIS

Geographical Information Systems (GIS) are powerful tools in the field of invasive species management. GIS can be used to create potential distribution maps for all manner of taxa, including plants, animals, and diseases. GIS also performs well in the early detection and rapid assessment of invasive species. Here, we used GIS applications to investigate species richness and invasion patterns in fish in the United States (US) at the 6-digit Hydrologic Unit Code (HUC) level. We also created maps of potential spread of the cane toad (Bufo marinus) in the southeastern US at the 8-digit HUC level using regression and environmental envelope techniques. Equipped with this potential map, resource managers can target their field surveys to areas most vulnerable to invasion. Advances in GIS technology, maps, data, and many of these techniques can be found on websites such as the National Institute of Invasive Species Science (www.NIISS.org). Such websites provide a forum for data sharing and analysis that is an invaluable service to the invasive species community.

Conference Paper↗

USGS2014

The shallow stratigraphy and sand resources offshore from Cat Island, Mississippi

In collaboration with the U.S. Army Corps of Engineers, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center collected over 487 line kilometers (> 300 miles) of high-resolution geophysical data around Cat Island, Mississippi, to improve understanding of the island's geologic evolution and identify potential sand resources for coastal restoration. In addition, 40 vibracores were collected on and around the island, generating more than 350 samples for grain-size analysis. The results indicate that the geologic evolution of Cat Island has been influenced by deltaic, lagoonal/estuarine, tidal, and oceanographic processes, resulting in a stratigraphic record that is quite complex. The region north of the island is dominated by lagoonal/estuarine deposition, whereas the region south of the island is dominated by deltaic and tidal deposition. In general, the veneer of modern sediment surrounding the island is composed of newly deposited sediment and highly reworked relict sediments. The region east of the island shows the interplay of antecedent barrier-island change with delta development despite a significant ravinement of sediments. The data show from little to no modern sediment east of the island, exposing relict sediments at the seafloor. Finally, the data reveal four subaqueous sand units around the island. Two of the units are northwest of the modern island and one is southwest. Given the dominant, westward, longshore transport along the Mississippi and Alabama barrier islands, the geographic location of these three units suggests that they do not contribute to the modern sediment budget of Cat Island. The last unit is directly east of the island and represents the antecedent island platform that has supplied sand over geologic time for creation of the spits that form the eastern shoreline. Because of its location east of the island, the antecedent island unit may still supply sediment to the island today.

Mississippi↗

USGS1986

Water demands in Kansas, 1944-84

The State of Kansas has administered water rights according to an appropriations doctrine since 1945. Water rights are issued by the Kansas State Board of Agriculture, Division of Water Resources, for eight categories of beneficial use. Water rights data and limited information on reported water use are stored on a computerized State data base; the U.S. Geological Survey cooperates with the State on maintenance of this system. This report analyzes trends in appropriations from 1944-84 for surface and groundwater for three major categories of use: irrigation, public supply, and industry. Demands for water, represented by these appropriations, are compared for three geographic areas within the State. These areas correspond to general patterns of water availability, population, and enterprises. As of 1984, 87% of the water appropriated for the three major types of use was for irrigation; most of this demand was for groundwater in the western one-third of the State. Seventy-five percent of the water demands in the central one-third of Kansas were met by groundwater; appropriations for irrigation represent the largest demand on water supplies in this area but must compete with appropriations for public supply and industry. Demands for surface water have increased substantially only in the eastern part of the State for industrial use and public supplies. The most prominent trends in water rights permit activity were related to climatic fluctuations, particularly the drought of the 1950's, legislative changes in the 1970 's requiring permits, and growth of urban populations in the central and eastern areas of the State. Analysis of trends in water appropriations can be useful in understanding the water issues facing Kansas in the future. (Author 's abstract)

Water-Resources Investigations Report↗

USGS2002

Geographic techniques and recent applications of remote sensing to landscape-water quality studies

This article overviews recent advances in studies of landscape-water quality relationships using remote sensing techniques. With the increasing feasibility of using remotely-sensed data, landscape-water quality studies can now be more easily performed on regional, multi-state scales. The traditional method of relating land use and land cover to water quality has been extended to include landscape pattern and other landscape information derived from satellite data. Three items are focused on in this article: 1) the increasing recognition of the importance of larger-scale studies of regional water quality that require a landscape perspective; 2) the increasing importance of remotely sensed data, such as the imagery-derived normalized difference vegetation index (NDVI) and vegetation phenological metrics derived from time-series NDVI data; and 3) landscape pattern. In some studies, using landscape pattern metrics explained some of the variation in water quality not explained by land use/cover. However, in some other studies, the NDVI metrics were even more highly correlated to certain water quality parameters than either landscape pattern metrics or land use/cover proportions. Although studies relating landscape pattern metrics to water quality have had mixed results, this recent body of work applying these landscape measures and satellite-derived metrics to water quality analysis has demonstrated their potential usefulness in monitoring watershed conditions across large regions.

Water, Air, & Soil Pollution↗

USGS2001

Fine-scale population structure Atlantic salmon from Maine's Penobscot River drainage

We report a survey of microsatellite DNA variation in Atlantic salmon from the unimpounded lower reaches of Maine's Penobscot River. Our analysis indicates that Atlantic salmon in the Penobscot River are distinct from other populations that have little or no history of human-mediated repopulation, including two of its tributaries, Cove Brook and Kenduskeag Stream, another Maine river, the Ducktrap, and Canada's Miramichi and Gander rivers. Significant heterogeneity was detected in allele frequency among all three subpopulations sampled in the Penobscot drainage. The high resolution of the 12-locussuite was quantified using maximum likelihood assignment tests, which correctly identified the source of 90.4–96.1% of individuals from within the Penobscot drainage. Current populations are clearly isolated from each other, however we are unable to determine from the present data whether the populations in Cove Brook and Kenduskeag Stream are recently diverged from populations stocked into the Penobscot River over the last century, or are aboriginal in origin. The degree of population structure identified in the Penobscot drainage is noteworthy in light of its lengthy history of systematic restocking, the geographic proximity of the subpopulations, and the extent of the differentiation. Similar population structure on this extremely limited geographic scale could exist among Atlantic salmon runs elsewhere in Maine and throughout the species' range and should be taken into account for future management decisions.

Maine↗

USGS2025

Peak streamflow trends in Montana and northern Wyoming and their relation to changes in climate, water years 1921–2020

Frequency analysis on annual peak streamflow (hereinafter, peak flow) is essential to water-resources management applications, including critical structure design (for example, bridges and culverts) and floodplain mapping. Nonstationarity is a statistical property of a peak-flow series such that the distributional properties (the mean, variance, or skew) change either gradually (monotonic trend) or abruptly (shift, step change or change point) through time. Not incorporating or accounting for observed nonstationarity into peak-flow frequency analysis might result in a poor representation of the true probability of large floods and thus misrepresent the actual flood risks to life and property. This report summarizes how hydroclimatic variability might affect the temporal and spatial distributions of peak-flow data in the State of Montana (and northern Wyoming) and is part of a larger study to document peak-flow nonstationarity and hydroclimatic changes across a nine-State region consisting of Illinois, Iowa, Michigan, Minnesota, Missouri, Montana, North Dakota, South Dakota, and Wisconsin. 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 flows. This study was completed in cooperation with the Montana Department of Natural Resources and Conservation. The purpose of this report is to characterize temporal and spatial patterns of nonstationarity in peak flows and hydroclimatology in Montana and northern Wyoming. In this evaluation, peak-flow, daily streamflow, and model-simulated gridded climatic data were examined for monotonic trends, change points, and other statistical properties that might indicate changing climatic and environmental conditions. This report includes background information on the study area, the history of U.S. Geological Survey peak-flow data collection and frequency analysis in Montana, and the review of research relating to hydroclimatic variability and change in Montana. This study might help provide a framework for addressing potential nonstationarity issues in peak-flow frequency updates that commonly are completed by the U.S. Geological Survey in cooperation with other agencies throughout the Nation. The analytical structure of this study includes analyses of monotonic trends and change points in numerous hydroclimatic variables in assigned 30-, 50-, 75-, and 100-year analysis periods. For Montana and part of Wyoming, the 30-, 50-, 75, and 100-year analyses included 157, 70, 48, and 12 streamgages, respectively. For those streamgages, nonstationarities were analyzed in the following variables: (1) climatic variables, including annual and seasonal (winter, spring, summer, and fall) temperature and precipitation; (2) daily streamflow variables, including the annual center of volume duration, annual center of volume median, and peaks over threshold with a mean of four events per year; and (3) annual peak-flow variables, including peak-flow timing and magnitude. A likelihood approach was used to express statistical confidence and assign the nonstationarity results as likely upward or downward (highest statistical confidence), somewhat likely upward or downward (less statistical confidence), or about as likely as not (little statistical confidence; hereinafter, neutral). For the nonstationarity analyses of the climatic, daily streamflow, and peak-flow variables, the results are presented in detail and discussed with respect to statewide patterns and geographic variability. For each of the 30-, 50-, and 75-year analyses, peak-flow change-point and monotonic trend analyses were compiled for streamgages classified with likely downward or likely upward trends. For those streamgages, the associated basin characteristics and nonstationarity results for peak-flow timing, daily streamflow, and climatic variables were investigated and statistically compared to discern associations among other variables that might contribute to the peak-flow nonstationarity results. The 50- and 75-year peak-flow nonstationarities identified in this study are mostly downward, in association with mostly upward temperature and potential evapotranspiration:precipitation monotonic trends. For the 50-, 75-, and 100-year analyses, the peak-flow change points are predominantly downward and are concentrated in the 1970s and 1980s, which indicates general consistency among the longer trend periods. These findings are in association with substantial research documenting globally rising temperature and atmospheric greenhouse gas concentrations that might be largely attributed to anthropogenic activities. Anthropogenic effects might represent long-term (on the order of several decades to more than a century) climate changes that might happen within highly variable natural climate fluctuations. Several paleo studies in the north-central United States have indicated that hydroclimatic extremes (that is, low- and high-streamflow conditions) before European settlement have been outside of extremes since the 1900s. Depending on the interactions of anthropogenic effects and natural climate variability, extreme high-streamflow conditions might occur in the future, even in the presence of long-term downward peak-flow trends.

Montana, Wyoming↗

USGS2022

Analysis of surface water trends for the conterminous United States using MODIS satellite data, 2003–2019

Satellite imagery is commonly used to map surface water extents over time, but many approaches yield discontinuous records resulting from cloud obstruction or image archive gaps. We applied the Dynamic Surface Water Extent (DSWE) model to downscaled (250-m) daily Moderate Resolution Imaging Spectroradiometer (MODIS) data in Google Earth Engine to generate monthly surface water maps for the conterminous United States (US) from 2003 through 2019. The aggregation of daily observations to monthly maps of maximum water extent produced records with diminished cloud and cloud shadow effects across most of the country. We used the continuous monthly record to analyze spatiotemporal surface water trends stratified within Environmental Protection Agency Ecoregions. Although not all ecoregion trends were significant ( p < 0.05), results indicate that much of the western and eastern US underwent a decline in surface water over the 17-year period, while many ecoregions in the Great Plains had positive trends. Trends were also generated from monthly streamgage discharge records and compared to surface water trends from the same ecoregion. These approaches agreed on the directionality of trend detected for 54 of 85 ecoregions, particularly across the Great Plains and portions of the western US, whereas trends were not congruent in select western deserts, the Great Lakes region, and the southeastern US. By describing the geographic distribution of surface water over time and comparing these records to instrumented discharge data across the conterminous US, our findings demonstrate the efficacy of using satellite imagery to monitor surface water dynamics and supplement traditional instrumented monitoring.

Water Resources Research↗

USGS2022

California Deepwater Investigations and Groundtruthing (Cal DIG) I, volume 3 — Benthic habitat characterization offshore Morro Bay, California

Coastal and Marine Ecological Classification Standard (CMECS) geoform, substrate, and biotic component geographic information system (GIS) products were developed for the U.S. Exclusive Economic Zone (U.S. EEZ) of south-central California in the region of Santa Lucia Bank motivated by interest in development of offshore wind-energy capacity and infrastructure. The Bureau of Ocean Energy Management (BOEM), in coordination with the State of California and many other members of the California Task Force, issued calls for information in 2018 for the study area offshore of Morro Bay, California. The study area is in depths of 500 to 1,200 meters (m) and adjacent to a decommissioned nuclear power plant with a developed electric grid connection, and in an area of high wind resource. BOEM is the lead agency responsible for planning and leasing in the U.S. EEZ and funded this project to assess baseline conditions of, and the potential effects on, the seafloor environment. This project, carried out by the U.S. Geological Survey (USGS), resulted in three reports: one on biological analysis of seafloor video data, one on analysis of the geologic framework and hazards, and this report on seafloor habitat. The study area consists of 8,424 square kilometers (km 2 ) of multibeam echo sounder (MBES) data acquired during five surveys from 2016 to 2019. Remotely operated vehicle (ROV) video was acquired in 2019 to supervise the classification of the MBES data into habitats. Derivatives of the MBES data were classified into 16 unique biotopes, 6 substrate types, 28 modifier groups, and 22 geoforms. The study area substrate is predominantly soft sediment (mud and fine sand) covering 7,804 km 2 (92.7 percent) of the area. Mixed substrate areas on rocky banks, channel scarps, and the shelf break comprise 404 km 2 (4.8 percent) of the study area. Hard substrate areas are found predominantly on the tops and flanks of banks and on bank ridges that separate canyons incising the banks. Hard substrates comprise 211 km 2 of the study area (2.5 percent). After the bathymetry and backscatter raster images (rasters) were classified, manual editing was also done to remove noise artifacts. This effort was not completely successful and there are numerous erroneous small areas in the rasters that have been passed on to the CMECS polygon product. Nearly 120,000 annotations of organisms and their habitat were made from 25 video transects selected from 185 hours of ROV video. In total, 2,714 km 2 of seafloor were successfully assigned to biotopes. Some biotopes were assigned to separate areas spatially distant from the transects that define the biotope. Expected relations between physical habitat and biota such as the number of species and the substrate induration and rugosity were verified. Slope is typically a predictive variable and was used in the classification of habitat, but the ground truth used for biotic component analysis included very little steeply sloping area. Ground-truth ROV operations were reduced by the sea state; additional ground truth could improve the biotic results and increase confidence in the spatial distribution of classifications reported here.

California↗

USGS2019

Flood-inundation maps for the Yellow River from River Drive to Centerville Highway, Gwinnett County, Georgia

Digital flood-inundation maps for a 16.4-mile reach of the Yellow River in Gwinnett County, Georgia, from 0.5 mile upstream from River Drive to Centerville Highway (Georgia State Route 124) were developed to depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at two U.S. Geological Survey (USGS) streamgages in the mapped area. The maps for the 9.0-mile reach from 0.5 mile upstream from River Drive to Stone Mountain Highway (U.S. Route 78) are referenced to the streamgage Yellow River near Snellville, Ga. (station 02206500), and the maps for the 7.4-mile reach from Stone Mountain Highway to Centerville Highway are referenced to the streamgage Yellow River at Ga. 124, near Lithonia, Ga. (02207120). Real-time stage information from these streamgages can be used with these maps to estimate near real-time areas of inundation. The forecasted peak-stage information for the USGS streamgages Yellow River near Snellville, Ga. (02206500), and Yellow River at Ga. 124, near Lithonia, Ga. (02207120), can be used in conjunction with the maps developed for this study to show predicted areas of flood inundation. A one-dimensional step-backwater model was developed using the U.S. Army Corps of Engineers Hydrologic Engineering Center's River Analysis System (HEC–RAS) software for the Yellow River and was used to compute flood profiles for a 16.4-mile reach of the Yellow River. The hydraulic model was then used to simulate 16 water-surface profiles at 1.0-foot (ft) intervals at the Yellow River near Snellville streamgage and 17 water-surface profiles at 1.0-ft intervals at the Yellow River near Lithonia streamgage. At the Yellow River near Snellville streamgage, the profiles ranged from a stage of 18.0 ft, which is 819.1 ft above the North American Vertical Datum of 1988 (NAVD 88), to a stage of 33.0 ft, which is 834.1 ft above NAVD 88. At the Yellow River near Lithonia streamgage, the profiles ranged from the National Weather Service action stage of 13.0 ft, which is 732.5 ft above NAVD 88, to a stage of 29.0 ft, which is 748.5 ft above NAVD 88. The simulated water-surface profiles were then combined with a geographic information system digital elevation model—derived from light detection and ranging (lidar) data having a 5.0-ft horizontal resolution—to delineate the area flooded at each 1.0-ft interval of stream stage for both streamgages.

Georgia↗

USGS1981

Compressing interpreted satellite imagery for geographic information systems applications over extensive regions

Image processing systems (IPS) and techniques effectively transform satellite imagery into data for input into a spatial database. Geographic information systems (GIS), consisting of graphic input and spatial database management subsystems, are capable of processing digital map and map overlay data to build and manipulate a spatial database. These systems can be successfully integrated to create a successful spatial data handling capability provided certain obstacle are understood and overcome. One of the obstacles faced by all spatial data handling activities involving the extensive regions is the tremendous volume of areal data. Raster formats for representing areal data provide a means of easily integrating IPS and GIS. A compressed raster format has been developed for handling map/image data which greatly reduce the volume of spatial data. By using compressed data strings as basic spatial entities for areal data sets, many complex data processing operations can be simplified. A second set of related problems deals with how this format and other representations of spatial entities, such as vector formats for point and line features, can be interrelated for manipulation, retrieval, and analysis by a spatial database management subsystem. Methods have been developed for interrelating areal data sets in the raster format with point and line data in a vector format and these are described.

Pecora VII Symposium↗

USGS2014

Genetic analysis of invasive Asian Black Carp ( Mylopharyngodon piceus ) in the Mississippi River Basin: evidence for multiple introductions

Invasive Asian Black Carp ( Mylopharyngodon piceus ) have been present in USA aquaculture facilities since the 1980s and wild Black Carp have been found in the Mississippi River Basin since the early 1990s. This study characterizes the genetic diversity and relatedness of the Basin’s Black Carp and clarifies the introduction history. Analyses focused on three mitochondrial markers (control region, cytochrome- b , and 16S) and seven nuclear microsatellite markers ( nDNA ), using aquaculture and wild-caught samples collected in the upper and lower Mississippi Basin. Of the three mitochondrial haplotypes, two were shared between the aquaculture and wild populations, while a third was only present in upper Mississippi wild-caught specimens. Due to the presence of diploid and triploid fish, microsatellite markers were scored as pseudodominant and revealed low polymorphism (N A = 4.6, N A Ave = 1.5). Nuclear Bayesian clustering analyses identified two genetically distinct groups and four subclusters, each primarily composed of a unique haplotype. Samples from three aquaculture farms were assigned to group 1, while a fourth farm included samples from both groups 1 and 2. Wild-caught fish from the upper Basin were predominantly group 1, whereas wild samples from the lower Mississippi were assigned to both genetic groups. The presence of divergent haplotypes and distinct nDNA groups, along with geographic distribution patterns, indicate that wild populations in the basin likely resulted from multiple introductions. Genetic similarities between wild and captive populations support claims that aquaculture is the introduction source, but a shortage of samples and a history of repeated transfers among facilities obscure the precise pathway.

Mississippi River Basin↗