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At least 919 records · Page 51Linked to original sources
USGS2011

Geospatial characteristics of Florida's coastal and offshore environments: Administrative and political boundaries and offshore sand resources

The Geospatial Characteristics Geopdf of Florida's Coastal and Offshore Environments is a comprehensive collection of geospatial data describing the political and natural resources of Florida. This interactive map provides spatial information on bathymetry, sand resources, military areas, marine protected areas, cultural resources, locations of submerged cables, and shipping routes. The map should be useful to coastal resource managers and others interested in the administrative and political boundaries of Florida's coastal and offshore region. In particular, as oil and gas explorations continue to expand, the map may be used to explore information regarding sensitive areas and resources in the State of Florida. Users of this geospatial database will find that they have access to synthesized information in a variety of scientific disciplines concerning Florida's coastal zone. This powerful tool provides a one-stop assembly of data that can be tailored to fit the needs of many natural resource managers.

Scientific Investigations Map↗
USGS2016

Peak-flow frequency analyses and results based on data through water year 2011 for selected streamflow-gaging stations in or near Montana: Chapter C in Montana StreamStats

Chapter C of this Scientific Investigations Report documents results from a study by the U.S. Geological Survey, in cooperation with the Montana Department of Transportation and the Montana Department of Natural Resources, to provide an update of statewide peak-flow frequency analyses and results for Montana. The purpose of this report chapter is to present peak-flow frequency analyses and results for 725 streamflow-gaging stations in or near Montana based on data through water year 2011. The 725 streamflow-gaging stations included in this study represent nearly all streamflowgaging stations in Montana (plus some from adjacent states or Canadian Provinces) that have at least 10 years of peak-flow records through water year 2011. For 29 of the 725 streamflow-gaging stations, peak-flow frequency analyses and results are reported for both unregulated and regulated conditions. Thus, peak-flow frequency analyses and results are reported for a total of 754 analyses. Estimates of peak-flow magnitudes for 66.7-, 50-, 42.9-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities are reported. These annual exceedance probabilities correspond to 1.5-, 2-, 2.33-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals.

Montana↗
USGS2011

Geospatial characteristics of Florida's coastal and offshore environments: Coastal habitats, artificial reefs, wrecks, dumping grounds, harbor obstructions and offshore sand resources

The Geospatial Characteristics GeoPDF of Florida's Coastal and Offshore Environments is a comprehensive collection of geospatial data describing the political boundaries and natural resources of Florida. This interactive map provides spatial information on bathymetry, sand resources, coastal habitats, artificial reefs, shipwrecks, dumping grounds, and harbor obstructions. The map should be useful to coastal resource managers and others interested in marine habitats and submerged obstructions of Florida's coastal region. In particular, as oil and gas explorations continue to expand, the map may be used to explore information regarding sensitive areas and resources in the State of Florida. Users of this geospatial database will have access to synthesized information in a variety of scientific disciplines concerning Florida's coastal zone. This powerful tool provides a one-stop assembly of data that can be tailored to fit the needs of many natural resource managers. The map was originally developed to assist the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) and coastal resources managers with planning beach restoration projects. The BOEMRE uses a systematic approach in planning the development of submerged lands of the Continental Shelf seaward of Florida's territorial waters. Such development could affect the environment. BOEMRE is required to ascertain the existing physical, biological, and socioeconomic conditions of the submerged lands and estimate the impact of developing these lands. Data sources included the National Oceanic and Atmospheric Administration, BOEMRE, Florida Department of Environmental Protection, Florida Geographic Data Library, Florida Fish and Wildlife Conservation Commission, Florida Natural Areas Inventory, and the State of Florida, Bureau of Archeological Research. Federal Geographic Data Committee (FGDC) compliant metadata are provided as attached xml files for all geographic information system (GIS) layers.

Florida↗
USGS2024

Design, development, and implementation of IsoBank: A centralized repository for isotopic data

Stable isotope data have made pivotal contributions to nearly every discipline of the physical and natural sciences. As the generation and application of stable isotope data continues to grow exponentially, so does the need for a unifying data repository to improve accessibility and promote collaborative engagement. This paper provides an overview of the design, development, and implementation of IsoBank , a community-driven initiative to create an open-access repository for stable isotope data implemented online in 2021. A central goal of IsoBank is to provide a web-accessible database supporting interdisciplinary stable isotope research and educational opportunities. To achieve this goal, we convened a multi-disciplinary group of over 40 analytical experts, stable isotope researchers, database managers, and web developers to collaboratively design the database. This paper outlines the main features of IsoBank and provides a focused description of the core metadata structure. We present plans for future database and tool development and engagement across the scientific community. These efforts will help facilitate interdisciplinary collaboration among the many users of stable isotopic data while also offering useful data resources and standardization of metadata reporting across eco-geoinformatics landscapes.

PLoS ONE↗
USGS2008

Hydrogeologic Framework of Onslow County, North Carolina, 2008

The unconsolidated sediments that underlie the Onslow County area are composed of interlayered permeable and impermeable beds, which overlie the crystalline basement rocks. The aquifers, composed mostly of sand and limestone, are separated by confining units composed mostly of clay and silt. The aquifers from top to bottom are the surficial, Castle Hayne, Beaufort, Peedee, Black Creek, and Upper and Lower Cape Fear aquifers. For this study, the Castle Hayne aquifer is informally divided into the upper and lower Castle Hayne aquifers. The eight aquifers and seven confining units of the Tertiary and Cretaceous strata beneath Onslow County are presented in seven hydrogeologic sections. The hydrogeologic framework was refined from existing interpretations by using geophysical logs, driller's logs, and other available data from 123 wells and boreholes.

Scientific Investigations Map↗
USGS2004

A statistical model and national data set for partioning fish-tissue mercury concentration variation between spatiotemporal and sample characteristic effects

Many Federal, Tribal, State, and local agencies monitor mercury in fish-tissue samples to identify sites with elevated fish-tissue mercury (fish-mercury) concentrations, track changes in fish-mercury concentrations over time, and produce fish-consumption advisories. Interpretation of such monitoring data commonly is impeded by difficulties in separating the effects of sample characteristics (species, tissues sampled, and sizes of fish) from the effects of spatial and temporal trends on fish-mercury concentrations. Without such a separation, variation in fish-mercury concentrations due to differences in the characteristics of samples collected over time or across space can be misattributed to temporal or spatial trends; and/or actual trends in fish-mercury concentration can be misattributed to differences in sample characteristics. This report describes a statistical model and national data set (31,813 samples) for calibrating the aforementioned statistical model that can separate spatiotemporal and sample characteristic effects in fish-mercury concentration data. This model could be useful for evaluating spatial and temporal trends in fishmercury concentrations and developing fish-consumption advisories. The observed fish-mercury concentration data and model predictions can be accessed, displayed geospatially, and downloaded via the World Wide Web (http://emmma.usgs.gov). This report and the associated web site may assist in the interpretation of large amounts of data from widespread fishmercury monitoring efforts.

Scientific Investigations Report↗
USGS2006

Simulation of daily pesticide concentrations from watershed characteristics and monthly climatic data

A time-series model was developed to simulate daily pesticide concentrations for streams in the coterminous United States. The model was based on readily available information on pesticide use, climatic variability, and watershed charac-teristics and was used to simulate concentrations for four herbicides [atrazine, ethyldipropylthiocarbamate (EPTC), metolachlor, and trifluralin] and three insecticides (carbofuran, ethoprop, and fonofos) that represent a range of physical and chemical properties, application methods, national application amounts, and areas of use in the United States. The time-series model approximates the probability distributions, seasonal variability, and serial correlation characteristics in daily pesticide concentration data from a national network of monitoring stations. The probability distribution of concentrations for a particular pesticide and station was estimated using the Watershed Regressions for Pesticides (WARP) model. The WARP model, which was developed in previous studies to estimate the probability distribution, was based on selected nationally available watershed-characteristics data, such as pesticide use and soil characteristics. Normality transformations were used to ensure that the annual percentiles for the simulated concentrations agree closely with the percentiles estimated from the WARP model. Seasonal variability in the transformed concentrations was maintained by relating the transformed concentration to precipitation and temperature data from the United States Historical Climatology Network. The monthly precipitation and temperature values were estimated for the centroids of each watershed. Highly significant relations existed between the transformed concentrations, concurrent monthly precipitation, and concurrent and lagged monthly temperature. The relations were consistent among the different pesticides and indicated the transformed concentrations generally increased as precipitation increased but the rate of increase depended on a temperature-dependent growing-season effect. Residual variability of the transformed concentrations, after removal of the effects of precipitation and temperature, was partitioned into a signal (systematic variability that is related from one day to the next) and noise (random variability that is not related from one day to the next). Variograms were used to evaluate measurement error, seasonal variability, and serial correlation of the historical data. The variogram analysis indicated substantial noise resulted, at least in part, from measurement errors (the differences between the actual concen-trations and the laboratory concentrations). The variogram analysis also indicated the presence of a strongly correlated signal, with an exponentially decaying serial correlation function and a correlation time scale (the time required for the correlation to decay to e-1 equals 0.37) that ranged from about 18 to 66 days, depending on the pesticide type. Simulated daily pesticide concentrations from the time-series model indicated the simulated concentrations for the stations located in the northeastern quadrant of the United States where most of the monitoring stations are located generally were in good agreement with the data. The model neither consistently overestimated or underestimated concentrations for streams that are located in this quadrant and the magnitude and timing of high or low concentrations generally coincided reasonably well with the data. However, further data collection and model development may be necessary to determine whether the model should be used for areas for which few historical data are available.

Scientific Investigations Report↗
USGS2008

Evaluation of the Acoustic Doppler Velocity Meter for Computation of Discharge Records at Three Sites in Colorado, 2004-2005

The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board, conducted a study in 2004-2005 at three sites in Colorado: Bear Creek at Morrison, Clear Creek near Empire, and Redlands Canal near Grand Junction. The study was done to evaluate acoustic Doppler velocity meter (ADVM) technology in different hydrologic settings that are characteristic of many Colorado streamflow-gaging sites. ADVMs have been tested and used extensively in many parts of the United States by USGS but not in Colorado where relatively small, shallow, clear, coarse-bed streams that ice up in the winter may affect the ADVM suitability. In this study, ADVM instrumentation was successfully used and discharge computations compared favorably, generally within 5 to 10 percent, with conventional USGS stage/discharge methods at the three Colorado sites. However, two factors, encountered in this study, may adversely affect the use of ADVM technology in Colorado. First, for some streams, the depth required (about 1.5 feet for a side-looking instrument) cannot be met during low-flow periods of the year. Second, cold temperatures and freezing-thawing cycles can produce ice effects that could prevent collection of usable ADVM (and stage) data.

Scientific Investigations Report↗
USGS2011

Estimated loads of suspended sediment and selected trace elements transported through the Clark Fork basin, Montana, in selected periods before and after the breach of Milltown Dam (water years 1985-2009)

Milltown Reservoir is a National Priorities List Superfund site in the upper Clark Fork basin of western Montana where sediments enriched in trace elements from historical mining and ore processing have been deposited since the completion of Milltown Dam in 1908. Milltown Dam was breached on March 28, 2008, as part of Superfund remediation activities to remove the dam and excavate contaminated sediment that had accumulated in Milltown Reservoir. In preparation for the breach of Milltown Dam, permanent drawdown of Milltown Reservoir began on June 1, 2006, and lowered the water-surface elevation by about 10 to 12 feet. After the breach of Milltown Dam, the water-surface elevation was lowered an additional 17 feet. Hydrologic data-collection activities were conducted by the U.S. Geological Survey in cooperation with U.S. Environmental Protection Agency to estimate loads of suspended sediment and trace elements transported through the Clark Fork basin before and after the breach of Milltown Dam. This report presents selected results of the data-collection activities.

Scientific Investigations Report↗
USGS2011

Potential effects of roadside dry wells on groundwater quality on the Island of Hawai'i — Assessment using numerical groundwater models

Widespread use of dry wells to dispose of roadside runoff has raised concern about the potential effects on the quality of groundwater on the Island of Hawai‘i. This study used semi-generic numerical models of groundwater flow and contaminant transport to assess the potential effect of dry wells on groundwater quality on the Island of Hawai‘i. The semi-generic models are generalized numerical groundwater-flow and solute-transport models that have a range of aquifer properties and regional groundwater gradients that are characteristic for the island. Several semi-generic models were created to study the effect of dry wells in different hydrogeologic conditions, such as different unsaturated-zone thicknesses or different aquifer characteristics. Results indicate that mixing of contaminated water from the surface with contaminant-free water in the saturated aquifer immediately reduces the contaminant concentration. The amount the concentration is reduced depends on the hydraulic properties of the aquifer in a given area, the thickness of the unsaturated zone, and whether the infiltration is focused in a small area of a dry well or spread naturally over a larger area. Model simulations indicate that focusing infiltration of contaminated runoff through a dry well can substantially increase contaminant concentrations in the underlying saturated aquifer relative to infiltration under natural conditions. Simulated concentrations directly beneath a dry well were nearly 8 times higher than the simulated concentrations directly beneath a broad infiltration area representing the natural condition. Where dry wells are present, contaminant concentrations in the underlying saturated aquifer are lower when the unsaturated zone is thicker and higher when the unsaturated zone is thinner. Contaminant concentrations decline quickly as the contaminant plume migrates, with the regional groundwater flow, away from the dry well. The differences among concentrations resulting from the various unsaturated-zone thicknesses also diminish with distance from the dry well. At a horizontal distance of about 700 ft downgradient from the dry well, all simulated maximum concentrations were less than 1 percent of the concentration in the infiltration water; at about 0.5 mi downgradient from the dry well, all simulated concentrations were equal to or less than 0.1 percent. Actual concentrations may be even lower than indicated by the models because of processes such as decay and reaction that were not simulated. Hydrologic and geologic differences from one location to the next also affect contaminant concentrations—simulations using models with properties representative of aquifers in the Hilo area resulted in lower overall concentrations than models with properties representative of aquifers in the Kona area. Results from this study can be used to assess how contaminants entering a dry well may affect receiving waters in a variety of situations on the Island of Hawai‘i. Better assessment would be obtained by using results from models having the most similar conditions (such as climate, hydraulic properties, regional groundwater gradient) to the dry well in question. The results of this study can help determine which dry wells are likely to have the greatest effect on nearby receiving waters and where more specific data and analyses may be needed.

Hawaii↗
USGS2013

Circulation, mixing, and transport in nearshore Lake Erie in the vicinity of Villa Angela Beach and Euclid Creek, Cleveland, Ohio, September 11-12, 2012

Villa Angela Beach, on the Lake Erie lakeshore near Cleveland, Ohio, is adjacent to the mouth of Euclid Creek, a small, flashy stream draining approximately 23 square miles and susceptible to periodic contamination from combined sewer overflows (CSOs) (97 and 163 CSO events in 2010 and 2011, respectively). Concerns over high concentrations of Escherichia coli (E. coli) in water samples taken along this beach and frequent beach closures led to the collection of synoptic data in the nearshore area in an attempt to gain insights into mixing processes, circulation, and the potential for transport of bacteria and other CSO-related pollutants from various sources in Euclid Creek and along the lakefront. An integrated synoptic survey was completed by the U.S. Geological Survey on September 11–12, 2012, during low-flow conditions on Euclid Creek, which followed rain-induced high flows in the creek on September 8–9, 2012. Data-collection methods included deployment of an autonomous underwater vehicle and use of a manned boat equipped with an acoustic Doppler current profiler. Spatial distributions of water-quality measures and nearshore currents indicated that the mixing zone encompassing the mouth of Euclid Creek and Villa Angela Beach is dynamic and highly variable in extent, but can exhibit a large zone of recirculation that can, at times, be decoupled from local wind forcing. Observed circulation patterns during September 2012 indicated that pollutants from CSOs in Euclid Creek and water discharged from three shoreline CSO points within 2,000 feet of the beach could be trapped along Villa Angela Beach by interaction of nearshore currents and shoreline structures. In spite of observed coastal downwelling, denser water from Euclid Creek is shown to mix to the surface via offshore turbulent structures that span the full depth of flow. While the southwesterly longshore currents driving the recirculation pattern along the beach front were observed during the 2011–12 synoptic surveys, longshore currents with a southwesterly component capable of establishing the recirculation only occurred about 30 percent of the time from June 7 to October 6, 2012, based on continuous velocity data collected near Villa Angela Beach.

Ohio↗
USGS2017

A review of surface energy balance models for estimating actual evapotranspiration with remote sensing at high spatiotemporal resolution over large extents

Many approaches have been developed for measuring or estimating actual evapotranspiration ( ET a ), and research over many years has led to the development of remote sensing methods that are reliably reproducible and effective in estimating ET a . Several remote sensing methods can be used to estimate ET a at the high spatial resolution of agricultural fields and the large extent of river basins. More complex remote sensing methods apply an analytical approach to ET a estimation using physically based models of varied complexity that require a combination of ground-based and remote sensing data, and are grounded in the theory behind the surface energy balance model. This report, funded through cooperation with the International Joint Commission, provides an overview of selected remote sensing methods used for estimating water consumed through ET a and focuses on Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) and Operational Simplified Surface Energy Balance (SSEBop), two energy balance models for estimating ET a that are currently applied successfully in the United States. The METRIC model can produce maps of ET a at high spatial resolution (30 meters using Landsat data) for specific areas smaller than several hundred square kilometers in extent, an improvement in practice over methods used more generally at larger scales. Many studies validating METRIC estimates of ET a against measurements from lysimeters have shown model accuracies on daily to seasonal time scales ranging from 85 to 95 percent. The METRIC model is accurate, but the greater complexity of METRIC results in greater data requirements, and the internalized calibration of METRIC leads to greater skill required for implementation. In contrast, SSEBop is a simpler model, having reduced data requirements and greater ease of implementation without a substantial loss of accuracy in estimating ET a . The SSEBop model has been used to produce maps of ET a over very large extents (the conterminous United States) using lower spatial resolution (1 kilometer) Moderate Resolution Imaging Spectroradiometer (MODIS) data. Model accuracies ranging from 80 to 95 percent on daily to annual time scales have been shown in numerous studies that validated ET a estimates from SSEBop against eddy covariance measurements. The METRIC and SSEBop models can incorporate low and high spatial resolution data from MODIS and Landsat, but the high spatiotemporal resolution of ET a estimates using Landsat data over large extents takes immense computing power. Cloud computing is providing an opportunity for processing an increasing amount of geospatial “big data” in a decreasing period of time. For example, Google Earth Engine TM has been used to implement METRIC with automated calibration for regional-scale estimates of ET a using Landsat data. The U.S. Geological Survey also is using Google Earth Engine TM to implement SSEBop for estimating ET a in the United States at a continental scale using Landsat data.

Scientific Investigations Report↗
USGS2018

Flood frequency of rural streams in Mississippi, 2013

To improve flood-frequency estimates at rural streams in Mississippi, annual exceedance probability flows at gaged streams and regional regression equations used to estimate annual exceedance probability flows for ungaged streams were developed by using current geospatial data, new analytical methods, and annual peak-flow data through the 2013 water year. The regional regression equations were derived from statistical analyses of peak-flow data and basin characteristics for 281 streamgages and incorporated a newly developed study-specific skew coefficient at streamgages located in five subregional watersheds (Middle Tennessee-Elk, Mobile-Tombigbee, Lower Mississippi-Big Black, Pearl, and Pascagoula) in Mississippi. Three flood regions—A, B, and C—were identified based on residuals from the regional regression analyses and contain sites with similar basin characteristics. Analysis was not conducted for the fourth flood region, the Mississippi Alluvial Plain, because of insufficient long-term streamflow data and poorly defined basin characteristics.

Mississippi↗
USGS2020

Water withdrawals, uses, and trends in Florida, 2015

In 2015, the total amount of water withdrawn in Florida was estimated to be 15,319 million gallons per day (Mgal/d). Saline water accounted for 9,598 Mgal/d (63 percent) and freshwater accounted for 5,721 Mgal/d (37 percent) of the total. Groundwater accounted for 3,604 Mgal/d (63 percent) of freshwater withdrawals and surface water accounted for the remaining 2,117 Mgal/d (37 percent). Surface-water sources accounted for 9,401 Mgal/d (98 percent) of the saline-water withdrawals, and groundwater sources accounted for the remaining 198 Mgal/d (2 percent). The majority of groundwater withdrawals (almost 62 percent) in 2015 were from the Floridan aquifer system, which is used throughout most of the State while the majority of fresh surface-water withdrawals (52 percent) occurred in the Southern Florida Subregion, a hydrologic unit that includes Lake Okeechobee and canals in the Everglades Agricultural Area. Groundwater provided drinking water (public supplied and self-supplied) for 18.324 million people (92 percent of Florida’s population), and fresh surface water provided drinking water for 1.491 million people (8 percent). Overall, public supply accounted for 39 percent of the total freshwater withdrawals (ground and surface) and 53 percent of groundwater withdrawals, followed by agricultural self-supplied uses, which accounted for 37 percent of the total freshwater withdrawals and 28 percent of groundwater withdrawals. Other self-supplied groundwater withdrawals include commercial-industrial-mining self-supplied (8 percent), recreational-landscape irrigation and domestic self-supplied (5 percent each), and power generation (less than 1 percent). Agricultural self-supplied withdrawals accounted for 51 percent of fresh surface-water withdrawals, followed by power generation (19 percent), public supply (15 percent), recreational-landscape irrigation (10 percent), and commercial-industrial-mining self-supplied (5 percent). In 1975, agricultural water withdrawals accounted for 43 percent of the total freshwater withdrawals, followed by power generation (24 percent) and public supply (17 percent). By 2000, agricultural withdrawals increased to 48 percent of the total freshwater withdrawals, followed by public supply (30 percent). For 2015, agricultural self-supplied decreased to 37 percent of total freshwater withdrawals, and was surpassed by public supply at 39 percent. Over the 40-year period between 1975 and 2015, increases in freshwater withdrawals caused by large gains in population and the expansion of irrigated acreage were offset by decreases in water used for power generation and commercial-industrial-mining withdrawals. Since 2000, however, irrigated acreage has decreased statewide because of crop disease, storm damage, and urbanization. This decline, coupled with large gains in water conservation measures in the farming industry, has led to agricultural withdrawals in Florida being less than public-supply withdrawals for the first time since water-use data were first reported in 1965.

Florida↗
USGS2021

Estimating invertebrate response to changes in total nitrogen, total phosphorus, and specific conductance at sites where invertebrate data are unavailable

The purpose of this report is to describe a possible approach to estimate changes in invertebrate taxa richness at sites with known water-quality trends but no invertebrate data. In this study, data from 1,322 sites were used to describe invertebrate response to changes in total nitrogen, total phosphorus, or specific conductance, and to estimate changes in invertebrate taxa richness at 259 sites with reported water-quality trends but no invertebrate data. Sites were stratified using propensity score analysis to control for confounding factors (for example, climate, land use, land cover). Generalized linear models were developed to describe changes in invertebrate taxa richness along gradients of total nitrogen, total phosphorus, and specific conductance values. The magnitude and direction of invertebrate response to gradients of water quality varied among parameters and strata, with changes in invertebrate taxa richness per natural log unit change in concentration ranging from –7 to +6. However, estimated changes in invertebrate taxa richness at sites with known water-quality trends were much less and did not exceed three taxa until changes in concentration were greater than 50 percent. Applying this approach provides (1) a first screening to identify where changes in invertebrate taxa richness are likely to occur and (2) the necessary groundwork to improve estimation of invertebrate response to trends in water quality where biological data are lacking.

Scientific Investigations Report↗
USGS2023

External quality-assurance project report for the National Atmospheric Deposition Program’s National Trends Network and Mercury Deposition Network, 2019–20

The U.S. Geological Survey Precipitation Chemistry Quality Assurance project (PCQA) operated four distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program’s (NADP) National Trends Network (NTN) and Mercury Deposition Network (MDN) during 2019–20. The NTN programs included (1) a field audit program to evaluate sample contamination and stability, and (2) an interlaboratory comparison program to evaluate analytical laboratory performance. The MDN programs included the (3) system blank program to evaluate sample contamination and stability, and (4) an interlaboratory comparison program. The results indicated increased levels of sample contamination compared to previous years for NTN samples and decreased contamination in MDN samples. Strong analytical laboratory performance with low overall variability and bias in concentration data were indicated for the NTN’s Central Analytical Laboratory. A positive bias in the hydrogen ion concentrations in NTN samples during 2019 was eliminated by correction of a pH calibration protocol during 2020. The MDN’s Mercury Analytical Laboratory performance declined in 2020 compared to 2019 as indicated by increased variability in analytical results and a negative bias of approximately -1 nanogram per liter in the concentrations of total mercury. Slight perturbations in contamination levels in NTN samples and in analytical performance for MDN are considered small. The PCQA results indicate that NADP data continue to be of sufficient quality for applications in independent research and NADP data products, including spatial interpolations and time trends for chemical constituents in wet deposition. Small shifts in data quality indicated by the 2019–20 PCQA results are intended to be used for interpretation of the NADP data products.

Scientific Investigations Report↗
USGS2024

Hydrologic study of green infrastructure in poorly drained urbanized soils at RecoveryPark, Detroit, Michigan, 2014–21

Uncontrolled stormwater runoff volume is a legacy stressor on sewer-system capacity that is further compromised by the effects of aging infrastructure. Green stormwater infrastructure (GSI) has been used in a variety of designs and configurations (for example, bioretention) with the goal of increasing evapotranspiration and infiltration in the local water cycle. In practice, GSIs have variable effectiveness in reducing runoff volume. An urban residential site near Detroit, Michigan, called RecoveryPark was monitored for 8 years before and after GSI construction to evaluate how effectively the GSI reduced volumes of stormwater flowing to Detroit’s Water Resource Recovery Facility through combined sewer systems. In addition to the GSI, the study site included an urban farm where salad crops were grown in hoop houses. The monitoring approach was to characterize the urban water cycle through high-frequency measurements of inflows and outflows. Datasets included meteorological data, soils and sediment characteristics, groundwater levels, flows within the combined sewer system, and soils and water chemistry with specific focus on the disposition of road salt. Although land cover within the RecoveryPark sewershed was high-density residential in the 1950s, the sewershed included only one residence within the 8.74-acre sewershed during this study. Measurements of annual precipitation at the site exceeded long-term annual averages by more than 10 inches during 3 of the 8 years of study. Potential evapotranspiration was often greater than the measured precipitation that averaged 28–34 inches per year. As compared to underlying clay-rich sediments, soils data indicated relatively permeable sediments near land surface with estimated hydraulic conductivity of 0.75 inches per hour; however, these values decreased with increasing depth. Groundwater-level data revealed increases in groundwater storage as indicated by increases in seasonal groundwater levels and development of a groundwater mound adjacent to the GSI. These increases in groundwater levels were directly adjacent to swales designed to infiltrate stormwater and only became evident after installing the GSI. Flows within the combined sewer system included rainwater, septic effluent, groundwater infiltration, leakage from water-supply lines, and release of water stored in abandoned foundations. Dry-weather flows (no rain fell within the prior 3 days) averaged 7–10 gallons per minute, which were much greater than flows estimated by septic outflow alone. A set of estimated water budgets were compiled, and results showed large discrepancies in unaccounted flows. To further examine these discrepancies, dye-tracing within the combined sewer system helped examine the sources of water by relating flow volumes to drainage area. For one of the monitoring sites within the combined sewer system along the southeast side of the study area, flows estimated by dye concentrations were more than 10 percent greater than those measured by standard methods. Through peak-flow-regression analysis, a minimum of 2.4 million gallons of water per year were infiltrated or lost to evapotranspiration because of GSI construction. After site modifications were made by excavating gravel drains to improve drainage characteristics, estimated stormwater volumes within the combined sewer system returned to near preconstruction levels. The GSI was effectively bypassed to address slow infiltration rates and standing water; the bypass all but eliminated the potential benefits of volume reduction. Late in the project, a water-quality study was added to examine the transport of road salt and associated chloride within the GSI and the combined sewer system. Continuous specific conductance was used as a surrogate for chloride concentrations to estimate that 2,790 pounds of dissolved chloride passed through the sewershed during the winter months of late 2020 through early 2021. These data were collected after GSI modification, therefore most, if not all, of the chloride was transported directly to Detroit’s Water Resource Recovery Facility via the combined sewer system. Mixing diagrams using chloride and bromide concentrations of road salt, potable water, rainwater, groundwater, and water from the combined sewer system confirmed that water within the combined sewer system is a mix of these sources. The poor condition of the combined sewer system pipes and resulting unaccounted inflows added to the challenge of accurately monitoring and identifying sources and sinks of water within the RecoveryPark sewershed. Our research results suggest that—along with clear and quantifiable objectives—the catchment and site conditions should be well-characterized before determining the GSI design. In addition, the work presented in this report provides implications and lessons learned for effectiveness and future studies of GSI in urban settings. These efforts can be improved through increased communication between stakeholders, use of high-quality soils in GSI that have suitable hydraulic characteristics, redundant data-collection networks for critical data streams, and focusing meteorological-data collection within the GSI to obtain relevant evapotranspiration data.

Michigan↗
USGS2011

Geospatial characteristics of Florida's coastal and offshore environments: Distribution of important habitats for coastal and offshore biological resources and offshore sand resources

The Geospatial Characteristics GeoPDF of Florida's Coastal and Offshore Environments is a comprehensive collection of geospatial data describing the political boundaries and natural resources of Florida. This interactive map provides spatial information on bathymetry, sand resources, and locations of important habitats (for example, Essential Fish Habitats (EFH), nesting areas, strandings) for marine invertebrates, fish, reptiles, birds, and marine mammals. The map should be useful to coastal resource managers and others interested in marine habitats and submerged obstructions of Florida's coastal region. In particular, as oil and gas explorations continue to expand, the map can be used to explore information regarding sensitive areas and resources in the State of Florida. Users of this geospatial database will have access to synthesized information in a variety of scientific disciplines concerning Florida's coastal zone. This powerful tool provides a one-stop assembly of data that can be tailored to fit the needs of many natural resource managers. The map was originally developed to assist the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) and coastal resources managers with planning beach restoration projects. The BOEMRE uses a systematic approach in planning the development of submerged lands of the Continental Shelf seaward of Florida's territorial waters. Such development could affect the environment. BOEMRE is required to ascertain the existing physical, biological, and socioeconomic conditions of the submerged lands and estimate the impact of developing these lands. Data sources included the National Oceanic and Atmospheric Administration, BOEMRE, Florida Department of Environmental Protection, Florida Geographic Data Library, Florida Fish and Wildlife Conservation Commission, Florida Natural Areas Inventory, and the State of Florida, Bureau of Archeological Research. Federal Geographic Data Committee (FGDC) compliant metadata are provided as attached xml files for all geographic information system (GIS) layers.

Florida↗