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At least 577 records · Page 32Linked to original sources
USGS2015

High-resolution digital elevation model of lower Cowlitz and Toutle Rivers, adjacent to Mount St. Helens, Washington, based on an airborne lidar survey of October 2007

The lateral blast, debris avalanche, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the surrounding landscape. Lava domes were extruded during the subsequent eruptive periods of 1980–1986 and 2004–2008. More than three decades after the emplacement of the 1980 debris avalanche, high sediment production persists in the Toutle River basin, which drains the northern and western flanks of the volcano. Because this sediment increases the risk of flooding to downstream communities on the Toutle and lower Cowlitz Rivers, the U.S. Army Corps of Engineers (USACE), under the direction of Congress to maintain an authorized level of flood protection, continues to monitor and mitigate excess sediment in North and South Fork Toutle River basins to help reduce this risk and to prevent sediment from clogging the shipping channel of the Columbia River. From October 22–27, 2007, Watershed Sciences, Inc., under contract to USACE, collected high-precision airborne lidar (light detection and ranging) data that cover 273 square kilometers (105 square miles) of lower Cowlitz and Toutle River tributaries from the Columbia River at Kelso, Washington, to upper North Fork Toutle River (below the volcano's edifice), including lower South Fork Toutle River. These data provide a digital dataset of the ground surface, including beneath forest cover. Such remotely sensed data can be used to develop sediment budgets and models of sediment erosion, transport, and deposition. The U.S. Geological Survey (USGS) used these lidar data to develop digital elevation models (DEMs) of the study area. DEMs are fundamental to monitoring natural hazards and studying volcanic landforms, fluvial and glacial geomorphology, and surface geology. Watershed Sciences, Inc., provided files in the LASer (LAS) format containing laser returns that had been filtered, classified, and georeferenced. The USGS produced a hydro-flattened DEM from ground-classified points at Castle and Coldwater Lakes. Final results averaged about two laser last-return points per square meter. As reported by Watershed Sciences, Inc., vertical accuracy is 10 centimeters (cm) at the 95-percent confidence interval on bare road surfaces; however, over natural terrain, USGS found vertical accuracy to be 10–50 cm. This USGS data series contains the bare-earth lidar data as 1- and 10-meter (m) resolution Esri grid files. Digital-elevation data can be downloaded (1m_DEM.zip and 10m_DEM.zip), as well as a 1-m resolution hillshade image with pyramids (1m_hillshade.zip). These geospatial data files require geographic information system (GIS) software for viewing.

Washington↗
USGS1971

Geochemical Survey of Missouri: Plans and progress for fourth six-month period (January-June 1971)

This is the fourth six-month progress report on a reconnaissance geochemical survey of the State of Missouri. The survey was initiated in July, 1969, to provide epidemiologists of the Environmental Health Center of the University of Missouri with data on the variability in the geochemical environment throughout the State. It is a pilot program in that it is the first attempt to provide information of this kind for so large an area (69,420 sq. mi.), and it is expected that the approaches being developed will be applicable to other reconnaissance investigations designed for similar purposes. The general approach--common to all four phases of the program (rocks, soils, vegetation, and water)--now appears to have taken a final form. The approach to sampling has been described in a following section of the present report. The principal task remaining in the reconnaissance geochemical survey is to follow the general approach through to completion. Some special investigations of selected small areas have been completed (Connor, Shacklette, and Erdman, 1971; Connor, Erdman, Sims, and Ebens, 1971), others are underway, and still others may be started--depending on local situations, or problems, that are identified by us or brought to our attention by others. One important purpose of the reconnaissance survey is to provide background data on the general geochemical setting which may allow more meaningful assessments of local geochemical conditions.

Missouri↗
USGS1979

Test monitoring of prototype injection well, Waiale, Maui, Hawaii

A high-capacity prototype injection well was tested in the isthmus area of Maui, Hawaii. Pumping tests were made on April 14 and 15, 1978, and 10 injection tests were made between May 12 and June 30, 1978. Selected tests were monitored in order to obtain data which could be used to assess the effects of subsurface disposal on the ground water in the basal aquifer. Pumping and injection rates were measured. Basal-water head responses to pumping and injection were observed at the prototype well and at two observation wells located 435 and 6 ,100 feet from the prototype well. Water-quality samples were collected at the prototype well and the nearest observation well prior to testing. Samples of the injection water, as well as samples from the observation wells, were collected prior to and after the final test. The head data and water-quality data are presented in this report.

Hawaii↗
USGS2016

Water-level changes in the High Plains aquifer, Republican River Basin in Colorado, Kansas, and Nebraska, 2002 to 2015

The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. More than 95 percent of the water withdrawn from the High Plains aquifer is used for irrigation. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigation with groundwater in the aquifer area (about 1950). The Republican River Basin is 15.9 million acres (about 25,000 square miles) and is located in northeast Colorado, northern Kansas, and southwest Nebraska. The Republican River Basin overlies the High Plains aquifer for 87 percent of the basin area. Water-level declines had begun in parts of the High Plains aquifer within the Republican River Basin by 1964. In 2002, management practices were enacted in the Middle Republican Natural Resources District in Nebraska to comply with the Republican River Compact Final Settlement. The U.S. Geological Survey, in cooperation with the Middle Republican Natural Resources District, completed a study of water-level changes in the High Plains aquifer within the Republican River Basin from 2002 to 2015 to enable the Middle Republican Natural Resources District to assess the effect of the management practices, which were specified by the Republican River Compact Final Settlement. Water-level changes determined from this study are presented in this report. Water-level changes from 2002 to 2015 in the High Plains aquifer within the Republican River Basin, by well, ranged from a rise of 9.4 feet to a decline of 43.2 feet. The area-weighted, average water-level change from 2002 to 2015 in this part of the aquifer was a decline of 4.5 feet.

Colorado, Kansas, Nebraska↗
USGS2006

Water Quality and Algal Data for the North Umpqua River Basin, Oregon, 2005

The upper North Umpqua River Basin has experienced a variety of water-quality problems since at least the early 1990's. Several reaches of the North Umpqua River are listed as water-quality limited under section 303(d) of the Clean Water Act. Diamond Lake, a eutrophic lake that is an important source of water and nutrients to the upper North Umpqua River, is also listed as a water-quality limited waterbody (pH, nuisance algae). A draft Total Maximum Daily Load (TMDL) was proposed for various parameters and is expected to be adopted in full in 2006. Diamond Lake has supported potentially toxic blue-green algae blooms since 2001 that have resulted in closures to recreational water contact and impacts to the local economy. Increased populations of the invasive tui chub fish are reportedly responsible, because they feed on zooplankton that would otherwise control the algal blooms. The Final Environmental Impact Statement (FEIS) for the Diamond Lake Restoration Project advocates reduced fish biomass in Diamond Lake in 2006 as the preferred alternative. A restoration project scheduled to reduce fish biomass for the lake includes a significant water-level drawdown that began in January 2006. After the drawdown of Diamond Lake, the fish toxicant rotenone was applied to eradicate the tui chub. The lake will be refilled and restocked with game fish in 2007. Winter exports of nutrients from Diamond Lake during the restoration project could affect the summer trophic status of the North Umpqua River if retention and recycling in Lemolo Lake are significant. The FEIS includes comprehensive monitoring to assess the water quality of the restored Diamond Lake and the effects of that restoration downstream. One component of the monitoring is the collection of baseline data, in order to observe changes in the river's water quality and algal conditions resulting from the restoration of Diamond Lake. During July 2005, the USGS, in cooperation with Douglas County, performed a synoptic survey of water quality and algal conditions, the results of which can be used for comparison with post-restoration conditions in the river as well as with those documented in an earlier study in 1995. This report presents data from that survey.

Oregon↗
USGS1972

Low flows and temperatures of streams in the Seattle-Tacoma urban complex and adjacent areas, Washington

Data on the minimum flows of streams and water temperature are necessary for the proper planning and development of the water resources of urban Seattle-Tacoma and adjacent areas. The data on low flows are needed for such purposes as (1) designing and operating municipal and industrial water-supply systems; (2) classifying streams as to their potential for waste disposal; (3) defining the amount of water available for irrigation, for maintaining streamflow as required by law or agreement, and for fish propagation; and (4) designing water-storage facilities. Data on stream temperatures are important to many water users because of the many biological, chemical, and physical properties of water that are dependent on temperature. Agricultural and domestic users as well as municipal, industrial and fishery agencies are concerned with water temperatures. In this report, low-flow data are accompanied by information on seasonal variations in water temperatures at sites selected as representing regional stream-temperature patterns. Because low flows and high water temperatures commonly occur together, they may impose constraints on various uses of the region's streams. The following discussion deals first with low-flow trends in the region, then with stream temperatures, and finally with some of the resulting constraints.

Washington↗
USGS1995

Water-quality characteristics of five tributaries to the Chesapeake Bay at the Fall Line, Virginia, July 1988 through June 1993

Development in the Chesapeake Bay region has adversely affected the water quality of the Bay. The general degradation in the Bay has resulted in the decline of commercial fishing industries and has reduced the area of aquatic vegetation that provides food and habitat for fish and shellfish. In order to assess the effectiveness of programs aimed at reducing the effects of excess nutrients and suspended solids on Chesapeake Bay, it is necessary to quantify the loads of these constituents into the Bay, and to evaluate the trends in water quality. This report presents the results of a study funded by the Virginia Department of Environmental Quality Chesapeake Bay and Coastal Programs and the U.S. Geological Survey, to monitor and estimate loads of selected nutrients and suspended solids discharged to Chesapeake Bay from five major tributaries in Virginia. The water-quality data and load estimates provided in this report also will be used to calibrate computer models of Chesapeake Bay. Water-quality constituents were monitored in the James and Rappahannock Rivers over a 5-year period, and in the Pamunkey, Appomattox, and Mattaponi Rivers over a 4-year period. Water-quality samples were collected from July 1, 1988 through June 30, 1993, for the James and Rappahannock Rivers; from July 1, 1989 through June 30, 1993, for the Pamunkey and Appomattox Rivers; and from September 1,1989 through June 30, 1993, for the Mattaponi River. Water-quality samples were collected on a scheduled basis and during stormflow to cover a range in discharge conditions. Monitore water-quality constituents, for which loads were estimated include total suspended solids (residue, total at 105° Celsius), dissolved nitrite-plus-nitrate nitrogen, dissolved ammonia nitrogen, total Kjeldahl nitrogen, total nitrogen, total phosphorus, dissolved orthophosphorus, total organic carbon, and dissolved silica. Organic nitrogen concentrations were calculated from measurements of ammonia and total Kjeldahl nitrogen, and organic nitrogen loads were estimated using these calculations. Other selected water-quality constituents were monitored for which loads were not calculated. Daily mean load estimates of each constituent were computed by use of a seven-parameter log-linear regression model that uses variables of time, discharge, and seasonality. Concentration of total nitrogen ranged from less than 0.14 to 3.41 mg/L (milligrams per liter), with both extreme values occurring at the Rappahannock River. Concentration of total Kjeldahl nitrogen ranged from less than 0.1 mg/L in the James, Rappahannock, and Appomattox Rivers to 3.0 mg/L in the James River. Organic nitrogen was the predominant form of nitrogen at all stations except the Rappahannock River, where nitrite plus-nitrate nitrogen was predominant, and organic nitrogen comprised the majority of the measured total Kjeldahl nitrogen at all stations, ranging from 0.01 mg/L in the Appomattox River to 2.86 mg/L in the James River. Concentration of dissolved ammonia nitrogen ranged from 0.01 mg/L in the Pamunkey River to 0.54 mg/L at the James River. Concentration of nitrite-plusnitrate nitrogen ranged from 0.02 to 1.05 mg/L in the James River. Concentrations of total phosphorus ranged from less than 0.01 mg/L in the Rappahannock and the Mattaponi Rivers to 1.4 mg/L in the James River. Dissolved orthophosphorus ranged from less than 0.01 mg/L in all five rivers to 0.51 mg/L in the James River. Total suspended solids ranged from a concentration of less than 1 mg/L in all five rivers to 844 mg/L in the Rappahannock River. Total organic carbon ranged from 1.1 mg/L in the Appomattox River to 110 mg/L in the Rappahannock River. Dissolved silica ranged from 2.4 mg/L in the James River to 18 mg/L in the Appomattox River. The James and Rappahannock Rivers had high median concentrations and large ranges in concentrations for most constituents, probably because of a greater number of point and nonpoint sources of nutrients and suspended solids, and differences in land use when compared with the other basins. A significantly higher median concentration and greater range of dissolved orthophosphorus generally occurred at the James River than in all other rivers, which primarily is due to the greater number of point sources, such as municipal waste-water treatment plants. The Rappahannock River had significantly higher median concentrations and greater ranges of dissolved nitrite-plus-nitrate nitrogen and total nitrogen than other rivers, probably derived from agricultural sources. Total organic carbon was highest in the Mattaponi and Pamunkey River Basins that contain expanses of wetlands. The Appomattox River had the highest concentration of dissolved silica. The median monthly load of total nitrogen ranged from 16,500 kg (kilogram) in the Mattaponi River to 371,000 kg in the James River. Total Kjeldahl nitrogen ranged from a median monthly load of 12,500 kg in the Mattaponi River to 205,500 kg, also in the James River. Organic nitrogen comprised the majority of the total Kjeldahl nitrogen load in all five rivers, ranging from a median monthly load of 11,251 kg in the Mattaponi River to 3,299,500 kg in the James River. The median monthly load of dissolved ammonia nitrogen was 1,130 kg in the Mattaponi River and was as much as 21,050 kg in the James River, whereas nitrite-plus-nitrate nitrogen ranged from a median monthly load of 4,065 kg in the Mattaponi River to 156,500 kg in the James River. The median monthly load of total phosphorus ranged from 1,670 kg in the Mattaponi River to 61,600 kg in the James River, whereas the median monthly load of dissolved orthophosphorus ranged from 350 kg in the Mattaponi River to 25,900 kg in the James River. Total suspended solids ranged from a median monthly load of 241,500 kg in the Mattaponi River to 20,050,000 kg in the James River. Total organic carbon ranged from a median monthly load of 167,000 kg in the Mattaponi River to 2,100,000 kg in the James River. The median monthly load of dissolved silica ranged from 209,500 kg in the Mattaponi River to 3,625,000 kg in the James River. In general, annual loads for complete years of data collection were greatest at the James River for all constituents, probably because of the much higher discharge, greater basin size, and higher rates of runoff. Yields, or computations of loads per square mile of basin area, were generally highest at the Rappahannock River for total suspended solids, total Kjeldahl nitrogen, nitrite-plusnitrate nitrogen, and total nitrogen. Dissolved orthophosphorus was the only constituent with a yield consistently greater at the James River. Yields of total phosphorus were highest for the James and Rappahannock River basins, whereas yields of dissolved ammonia nitrogen, total organic carbon, and dissolved silica were similar for all five river basins. Quality-assurance analyses that compare the results of the Virginia Division of Consolidated Laboratory Services and the U.S. Geological Survey Laboratory indicate that there are statistically significant differences between the laboratories for several constituents. Differences between laboratories were found to be caused by differences in analytical reporting limits, differences in analytical technique, or a slight bias at both laboratories. Quality-assurance data were used to address analytical technique problems, and to qualify final concentrations and loads.

Virginia↗
USGS2017

Synthesis of data from high-frequency nutrient and associated biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California

Executive Summary This report is the second in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San Joaquin Delta of northern California (Delta). The purpose of this report is to synthesize the data available from a nutrient and water-quality HF (about every 15 minutes) monitoring network operated by the U.S. Geological Survey in the northern Delta. In this report, we describe the network and focus on the purpose of each station. We then present and discuss the available data, at various timescales—first at the monthly, seasonal, and inter-annual timescales, and second, for comparison, at the tidal and event timescales. As expected, we determined that there is substantial variability in nitrate-N concentrations at short timescales within hours, but also significant variability at longer timescales such as months or years. Resolving this variability is made possible by the HF data, with the largest variability caused by storms, tides, and diel biological processes. Given this large temporal variability, calculations of cumulative nutrient fluxes (for example, daily, monthly, or annual loads) is difficult without HF data. For example, in the Cache Slough, calculation of the annual load without the tidal variability resulted in a 30 percent underestimation of the true annual load value. We conclude that HF measurements are important for accurate determination of fluxes and loads in tidal environments, but, more importantly, provide important insights into processes and rates of nutrient cycling. This report, along with the other two reports of this series (Bergamaschi and others, 2017; Kraus, Bergamaschi, and others, 2017), was drafted in cooperation with the Delta Regional Monitoring Program to help scientists, managers, and planners understand how HF data improve our understanding of nutrient sources and sinks, drivers, and effects in the Delta. The first report in the series (Kraus, Bergamaschi, and others, 2017) provides an introduction to the reasons for and fundamental concepts behind using HF monitoring measurements, including a brief summary of nutrient status and trends in the Delta and an extensive literature review showing how and where other research and monitoring programs have used HF monitoring to improve our understanding of nutrient cycling. The report covers the various technologies available for HF nutrient monitoring and presents the different ways HF monitoring instrumentation may be used for fixed station and spatial assessments. Finally, it presents numerous examples of how HF measurements are currently (2017) being used in the Delta to examine how nutrients and nutrient cycling are related to aquatic habitat conditions. The third report in the series (Bergamaschi and others, 2017) provides the background, principles, and considerations for designing an HF nutrient-monitoring network for the Delta to address high-priority, nutrient-management questions. The report starts with discussion of the high‑priority management questions to be addressed, continues through discussion of the questions and considerations that place demands and constraints on network design, discusses the principles applicable to network design, and concludes with the presentation of three example nutrient-monitoring network designs for the Delta, proposed to address high-priority questions identified by the Delta Regional Monitoring Program (Delta Regional Monitoring Program Technical Advisory Committee, 2015).

California↗
USGS2007

Integrated geoscience studies in the Greater Yellowstone Area - Volcanic, tectonic, and hydrothermal processes in the Yellowstone geoecosystem

Yellowstone National Park, rimmed by a crescent of older mountainous terrain, has at its core the Quaternary Yellowstone Plateau, an undulating landscape shaped by forces of volcanism, tectonism, and later glaciation. Its spectacular hydrothermal systems cap this landscape. From 1997 through 2003, the United States Geological Survey Mineral Resources Program conducted a multidisciplinary project of Yellowstone National Park entitled Integrated Geoscience Studies of the Greater Yellowstone Area, building on a 130-year foundation of extensive field studies (including the Hayden survey of 1871, the Hague surveys of the 1880s through 1896, the studies of Iddings, Allen, and Day during the 1920s, and NASA-supported studies starting in the 1970s—now summarized in USGS Professional Paper 729 A through G) in this geologically dynamic terrain. The project applied a broad range of scientific disciplines and state-of-the-art technologies targeted to improve stewardship of the unique natural resources of Yellowstone and enable the National Park Service to effectively manage resources, protect park visitors from geologic hazards, and better educate the public on geologic processes and resources. This project combined a variety of data sets in characterizing the surficial and subsurface chemistry, mineralogy, geology, geophysics, and hydrothermal systems in various parts of the park. The sixteen chapters presented herein in USGS Professional Paper 1717, Integrated Geoscience Studies in the Greater Yellowstone Area—Volcanic, Tectonic, and Hydrothermal Processes in the Yellowstone Geoecosystem , can be divided into four major topical areas: (1) geologic studies, (2) Yellowstone Lake studies, (3) geochemical studies, and (4) geophysical studies. The geologic studies include a paper by Ken Pierce and others on the influence of the Yellowstone hotspot on landscape formation, the ecological effects of the hotspot, and the human experience and human geography of the greater Yellowstone ecosystem as influenced by the Yellowstone hotspot. Another paper by Paul Carrara describes the recent movement of a large landslide block dated by tree-ring analyses in the Tower Falls area. The section under Yellowstone Lake studies begins with a classic paper by J. David Love and others on ancestral Lake Yellowstone. Other papers in this section include results and interpretation of the high-resolution bathymetric, seismic reflection, and submersible studies by Lisa Morgan and others. Ken Pierce and others describe results from their studies of shorelines along Yellowstone Lake and their interpretation of inflation-deflation cycles, tilting, and faulting in the Yellowstone caldera. The influence of sublacustrine hydrothermal vent fluids on the geochemistry of Yellowstone Lake is described by Laurie Balistrieri and others. In Pat Shanks and others’ chapter, hydrothermal reactions, stable-isotope systematics, sinter deposition, and spire formation are related to the geochemistry of sublacustrine hydrothermal deposits in Yellowstone Lake. The geochemical studies section considers park-wide geochemical systems in Yellowstone National Park. In Bob Rye and Alfred Truesdell’s paper, the question of recharge to the deep thermal reservoir underlying the geysers and hot springs of Yellowstone National Park is discussed. Irving Friedman and Dan Norton report on the chloride flux emissions from Yellowstone in their paper questioning whether Yellowstone is losing its steam. Wildlife issues as addressed by examining trace-element and stable-isotope geochemistry are discussed in a chapter by Maurice Chaffee and others. In another chapter by Chaffee and others, natural and anthropogenic anomalies and their potential impact on the environment using geochemistry is reported. Pam Gemery-Hill and others present geochemical data for selected rivers, lake waters, hydrothermal vents, and subaerial geysers for the time interval of 1996–2004. The life cycle of gold deposits near the northeast corner of the park is discussed by Brad Van Gosen. Under the geophysical studies segment, Ray Kokaly and others use AVIRIS (Airborne Visible and Infrared Spectroscopy) data to map vegetation cover and microbial communities in Yellowstone National Park. Eric Livo and others report their results using AVIRIS data on hydrothermally altered rock and hot-spring deposits. In his final paper following a half century of scientific research, Irving Friedman presents data on monitoring changes in geothermal activity at Norris Geyser Basin using satellite telemetry. These papers summarize a near-decade-long effort by the USGS from the late 1990s to mid-2000s. In 2001, the USGS in cooperation with the National Park Service (Yellowstone National Park) and the University of Utah established the Yellowstone Volcano Observatory, the 5th volcano observatory in the United States.

Idaho, Montana, Wyoming↗
USGS2017

Designing a high-frequency nutrient and biogeochemical monitoring network for the Sacramento–San Joaquin Delta, northern California

Executive Summary This report is the third in a series of three reports that provide information about how high-frequency (HF) nutrient monitoring may be used to assess nutrient inputs and dynamics in the Sacramento–San Joaquin Delta, California (Delta). The purpose of this report is to provide the background, principles, and considerations for designing an HF nutrient-monitoring network for the Delta to address high-priority, nutrient-management questions. The report starts with discussion of the high-priority management questions to be addressed, continues through discussion of the questions and considerations that place demands and constraints on network design, discusses the principles applicable to network design, and concludes with the presentation of three example nutrient-monitoring network designs for the Delta. For three example network designs, we assess how they would address high-priority questions that have been identified by the Delta Regional Monitoring Program (Delta Regional Monitoring Program Technical Advisory Committee, 2015). This report, along with the other two reports of this series (Kraus and others, 2017; Downing and others, 2017), was drafted in cooperation with the Delta Regional Monitoring Program to help scientists, managers, and planners understand how HF data improve our understanding of nutrient sources and sinks, drivers, and effects in the Delta. The first report in the series (Kraus and others, 2017) provides an introduction to the reasons for and fundamental concepts behind using HF monitoring measurements, including a brief summary of nutrient status and trends in the Delta and an extensive literature review showing how and where other research and monitoring programs have used HF monitoring to improve our understanding of nutrient cycling. The report covers the various technologies available for HF nutrient monitoring and presents the different ways HF monitoring instrumentation may be used for both fixed station and spatial assessments. Finally, it presents numerous examples of how HF measurements are currently (2017) being used in the Delta to examine how nutrients and nutrient cycling are related to aquatic habitat conditions. The second report in the series (Downing and others, 2017) summarizes information about HF nutrient and associated biogeochemical monitoring in the north Delta. The report synthesizes data available from the nutrient and water quality monitoring network currently (2017) operated by the U.S. Geological Survey in this ecologically important region of the Delta. In the report, we present and discuss the available data at various timescales—first at the monthly, seasonal, and inter-annual timescales; and, second, for comparison, at the tidal and event timescales. As expected, we determined that there is substantial variability in nitrate concentrations at short timescales, such as within a few hours, but also significant variability at longer timescales such as months or years. This high variability affects calculation of fluxes and loads, indicating that HF monitoring is necessary for understanding and assessing flux-based processes and outcomes in Delta tidal environments.

California↗
USGS2015

Using a laboratory-based growth model to estimate mass- and temperature-dependent growth parameters across populations of juvenile Chinook Salmon

To estimate the parameters that govern mass- and temperature-dependent growth, we conducted a meta-analysis of existing growth data from juvenile Chinook Salmon Oncorhynchus tshawytscha that were fed an ad libitum ration of a pelleted diet. Although the growth of juvenile Chinook Salmon has been well studied, research has focused on a single population, a narrow range of fish sizes, or a narrow range of temperatures. Therefore, we incorporated the Ratkowsky model for temperature-dependent growth into an allometric growth model; this model was then fitted to growth data from 11 data sources representing nine populations of juvenile Chinook Salmon. The model fit the growth data well, explaining 98% of the variation in final mass. The estimated allometric mass exponent (b) was 0.338 (SE = 0.025), similar to estimates reported for other salmonids. This estimate of b will be particularly useful for estimating mass-standardized growth rates of juvenile Chinook Salmon. In addition, the lower thermal limit, optimal temperature, and upper thermal limit for growth were estimated to be 1.8°C (SE = 0.63°C), 19.0°C (SE = 0.27°C), and 24.9°C (SE = 0.02°C), respectively. By taking a meta-analytical approach, we were able to provide a growth model that is applicable across populations of juvenile Chinook Salmon receiving an ad libitum ration of a pelleted diet.

Transactions of the American Fisheries Society↗
USGS2003

Effects of hydrology on red mangrove recruits

Coastal wetlands along the Gulf of Mexico have been experiencing significant shifts in hydrology and salinity levels over the past century as a result of changes in sea level and freshwater drainage patterns. Local land management in coastal zones has also impacted the hydrologic regimes of salt marshes and mangrove areas. Parks and refuges in south Florida that contain mangrove forests have, in some cases, been ditched or impounded to control mosquito outbreaks and to foster wildlife use. And while mangroves dominate the subtropical coastlines of Florida and thrive in saltwater environments, little is known about how they respond to changes in hydrology under managed or variable tidal conditions. USGS researchers designed a study to evaluate the basic hydrological requirements of mangroves so that their health and survival may be more effectively managed in controlled impoundments and restored wetlands. Mangroves are commonly found in the intertidal zone (between low and high tides) in a rather broad spectrum of hydrologic settings. Because they thrive at the interface of land and sea, mangroves are subject to changes in freshwater flow (flow rate, nutrients, pollutants) and to marine influences (sea-level rise, salinity). Salinity has long been recognized as a controlling factor that determines the health and distribution of mangrove forests. Field and experimental observations indicate that most mangrove species achieve their highest growth potential under brackish conditions (modest salinity) between 10 and 20 parts per thousand (ppt). Yet, if provided with available propagules, successful regeneration, and limited competition from other plants, then mangroves can survive and thrive in freshwater systems as well. Because little is known about the growthand survival patterns of mangrove species relative to changing hydrology, USGS scientists conducted greenhouse and field experiments to determine how flooded or drained patterns of hydrology would influence growth of the red mangrove, Rhizophora mangle (fig. 1). Red mangrove propagules (recruits) of select sizes and genotypes (i.e., genetically similar groups) were planted both in greenhouses and in the field. Seedling growth was monitored in both studies on a quarterly basis for over a year; measurements included shoot growth, seedling height, and a final harvest of plant biomass.

Fact Sheet↗
USGS2005

Topogrid Derived 10 Meter Resolution Digital Elevation Model of Charleston, and Parts of Berkeley, Colleton, Dorchester and Georgetown Counties, South Carolina

EXPLANATION The purpose of developing a new 10m resolution digital elevation model (DEM) of the Charleston Region was to more accurately depict geologic structure, surfical geology, and landforms of the Charleston County Region. Previously, many areas northeast and southwest of Charleston were originally mapped with a 20 foot contour interval. As a result, large areas within the National Elevation Dataset (NED) depict flat terraced topography where there was a lack of higher resolution elevation data. To overcome these data voids, the new DEM is supplemented with additional elevation data and break-lines derived from aerial photography and topographic maps. The resultant DEM is stored as a raster grid at uniform 10m horizontal resolution. The elevation model contained in this publication was prodcued utilizing the ANUDEM algorthim. ANUDEM allows for the inclusion of contours, streams, rivers, lake and water body polygons as well as spot height data to control the development of the elevation model. A preliminary statistical analysis using over 788 vertical elevation check points, primarily located in the northeastern part of the study area, derived from USGS 7.5 Minute Topographic maps reveals that the final DEM, has a vertical accuracy of ?3.27 meters. A table listing the elevation comparison between the elevation check points and the final DEM is provided.

Open-File Report↗
USGS2006

Seaside, Oregon tsunami pilot study— Modernization of FEMA flood hazard maps

FEMA Flood Insurance Rate Map (FIRM) guidelines do not currently exist for conducting and incorporating tsunami hazard assessments that reflect the substantial advances in tsunami research achieved in the last two decades; this conclusion is the result of two FEMA-sponsored workshops and the associated Tsunami Focused Study. Therefore, as part of FEMA's Map Modernization Program, a Tsunami Pilot Study was carried out in the Seaside/Gearhart, Oregon, area to develop an improved Probabilistic Tsunami Hazard Assessment (PTHA) methodology and to provide recommendations for improved tsunami hazard assessment guidelines. The Seaside area was chosen because it is typical of many coastal communities in the section of the Pacific Coast from Cape Mendocino to the Strait of Juan de Fuca, and because State Agencies and local stakeholders expressed considerable interest in mapping the tsunami threat to this area. The study was an interagency effort by FEMA, U.S. Geological Survey and the National Oceanic and Atmospheric Administration, in collaboration with the University of Southern California, Middle East Technical University. Portland State University, Horning Geosciences, Northwest Hydraulics Consultants, and the Oregon Department of Geological and Mineral Industries. Draft copies and a briefing on the contents, results and recommendations of this document were provided to FEMA officials before final publication.

Oregon↗
USGS2015

Peak flow regression equations For small, ungaged streams in Maine: Comparing map-based to field-based variables

Regression equations to estimate peak streamflows with 1- to 500-year recurrence intervals (annual exceedance probabilities from 99 to 0.2 percent, respectively) were developed for small, ungaged streams in Maine. Equations presented here are the best available equations for estimating peak flows at ungaged basins in Maine with drainage areas from 0.3 to 12 square miles (mi 2 ). Previously developed equations continue to be the best available equations for estimating peak flows for basin areas greater than 12 mi 2 . New equations presented here are based on streamflow records at 40 U.S. Geological Survey streamgages with a minimum of 10 years of recorded peak flows between 1963 and 2012. Ordinary least-squares regression techniques were used to determine the best explanatory variables for the regression equations. Traditional map-based explanatory variables were compared to variables requiring field measurements. Two field-based variables—culvert rust lines and bankfull channel widths—either were not commonly found or did not explain enough of the variability in the peak flows to warrant inclusion in the equations. The best explanatory variables were drainage area and percent basin wetlands; values for these variables were determined with a geographic information system. Generalized least-squares regression was used with these two variables to determine the equation coefficients and estimates of accuracy for the final equations.

Maine↗
USGS2007

Time-optimum packet scheduling for many-to-one routing in wireless sensor networks

This paper studies the WSN application scenario with periodical traffic from all sensors to a sink. We present a time-optimum and energy-efficient packet scheduling algorithm and its distributed implementation. We first give a general many-to-one packet scheduling algorithm for wireless networks, and then prove that it is time-optimum and costs max(2N(u1) - 1, N(u 0) -1) time slots, assuming each node reports one unit of data in each round. Here N(u0) is the total number of sensors, while N(u 1) denotes the number of sensors in a sink's largest branch subtree. With a few adjustments, we then show that our algorithm also achieves time-optimum scheduling in heterogeneous scenarios, where each sensor reports a heterogeneous amount of data in each round. Then we give a distributed implementation to let each node calculate its duty-cycle locally and maximize efficiency globally. In this packet scheduling algorithm, each node goes to sleep whenever it is not transceiving, so that the energy waste of idle listening is also eliminated. Finally, simulations are conducted to evaluate network performance using the Qualnet simulator. Among other contributions, our study also identifies the maximum reporting frequency that a deployed sensor network can handle. ??2006 IEEE.

Conference Paper↗
USGS2007

Time-optimum packet scheduling for many-to-one routing in wireless sensor networks

This paper studies the wireless sensor networks (WSN) application scenario with periodical traffic from all sensors to a sink. We present a time-optimum and energy-efficient packet scheduling algorithm and its distributed implementation. We first give a general many-to-one packet scheduling algorithm for wireless networks, and then prove that it is time-optimum and costs [image omitted], N(u0)-1) time slots, assuming each node reports one unit of data in each round. Here [image omitted] is the total number of sensors, while [image omitted] denotes the number of sensors in a sink's largest branch subtree. With a few adjustments, we then show that our algorithm also achieves time-optimum scheduling in heterogeneous scenarios, where each sensor reports a heterogeneous amount of data in each round. Then we give a distributed implementation to let each node calculate its duty-cycle locally and maximize efficiency globally. In this packet-scheduling algorithm, each node goes to sleep whenever it is not transceiving, so that the energy waste of idle listening is also mitigated. Finally, simulations are conducted to evaluate network performance using the Qualnet simulator. Among other contributions, our study also identifies the maximum reporting frequency that a deployed sensor network can handle.

International Journal of Parallel, Emergent and Di↗
USGS2010

Estimated minimum discharge rates of the Deepwater Horizon spill— Interim report to the flow rate technical group from the Mass Balance Team

All of the calculations and results in this report are preliminary and intended for the purpose, and only for the purpose, of aiding the incident team in assessing the extent of the spilled oil for ongoing response efforts. Other applications of this report are not authorized and are not considered valid. Because of time constraints and limitations of data available to the experts, many of their estimates are approximate, are subject to revision, and certainly should not be used as the Federal Government's final values for assessing volume of the spill or its impact to the environment or to coastal communities. Each expert that contributed to this report reserves the right to alter his conclusions based upon further analysis or additional information. An estimated minimum total oil discharge was determined by calculations of oil volumes measured as of May 17, 2010. This included oil on the ocean surface measured with satellite and airborne images and with spectroscopic data (129,000 barrels to 246,000 barrels using less and more aggressive assumptions, respectively), oil skimmed off the surface (23,500 barrels from U.S. Coast Guard [USCG] estimates), oil burned off the surface (11,500 barrels from USCG estimates), dispersed subsea oil (67,000 to 114,000 barrels), and oil evaporated or dissolved (109,000 to 185,000 barrels). Sedimentation (oil captured from Mississippi River silt and deposited on the ocean bottom), biodegradation, and other processes may indicate significant oil volumes beyond our analyses, as will any subsurface volumes such as suspended tar balls or other emulsions that are not included in our estimates. The lower bounds of total measured volumes are estimated to be within the range of 340,000 to 580,000 barrels as of May 17, 2010, for an estimated average minimum discharge rate of 12,500 to 21,500 barrels per day for 27 days from April 20 to May 17, 2010.

Louisiana↗