Control of Culex quinquefasciatus in a storm drain system in Florida with attractive toxic sugar baits (ATSB)

USDA-ARS?s Scientific Manuscript database

Mosquitoes of the Culex pipiens group, including Culex quinquefasciatus, are important vectors of West Nile virus and other viruses around the world. Control of these mosquitoes in urban areas is often difficult because of the use of storm drains and other man-made structures as larval habitats. I...

Regression Techniques for Determining the Effective Impervious Area in Southern California Watersheds

NASA Astrophysics Data System (ADS)

Sultana, R.; Mroczek, M.; Dallman, S.; Sengupta, A.; Stein, E. D.

2016-12-01

The portion of the Total Impervious Area (TIA) that is hydraulically connected to the storm drainage network is called the Effective Impervious Area (EIA). The remaining fraction of impervious area, called the non-effective impervious area, drains onto pervious surfaces which do not contribute to runoff for smaller events. Using the TIA instead of EIA in models and calculations can lead to overestimates of runoff volumes peak discharges and oversizing of drainage system since it is assumed all impervious areas produce urban runoff that is directly connected to storm drains. This makes EIA a better predictor of actual runoff from urban catchments for hydraulic design of storm drain systems and modeling non-point source pollution. Compared to TIA, determining the EIA is considerably more difficult to calculate since it cannot be found by using remote sensing techniques, readily available EIA datasets, or aerial imagery interpretation alone. For this study, EIA percentages were calculated by two successive regression methods for five watersheds (with areas of 8.38 - 158mi2) located in Southern California using rainfall-runoff event data for the years 2004 - 2007. Runoff generated from the smaller storm events are considered to be emanating only from the effective impervious areas. Therefore, larger events that were considered to have runoff from both impervious and pervious surfaces were successively removed in the regression methods using a criterion of (1) 1mm and (2) a max (2 , 1mm) above the regression line. MSE is calculated from actual runoff and runoff predicted by the regression. Analysis of standard deviations showed that criterion of max (2 , 1mm) better fit the regression line and is the preferred method in predicting the EIA percentage. The estimated EIAs have shown to be approximately 78% to 43% of the TIA which shows use of EIA instead of TIA can have significant impact on the cost building urban hydraulic systems and stormwater capture devices.

Diazinon and chlorpyrifos loads in precipitation and urban and agricultural storm runoff during January and February 2001 in the San Joaquin River basin, California

USGS Publications Warehouse

Zamora, Celia; Kratzer, Charles R.; Majewski, Michael S.; Knifong, Donna L.

2003-01-01

The application of diazinon and chlorpyrifos on dormant orchards in 2001 in the San Joaquin River Basin was 24 percent less and 3.2 times more than applications in 2000, respectively. A total of 16 sites were sampled during January and February 2001 storm events: 7 river sites, 8 precipitation sites, and 1 urban storm drain. The seven river sites were sampled weekly during nonstorm periods and more frequently during storm runoff from a total of four storms. The monitoring of storm runoff at a city storm drain in Modesto, California, occurred simultaneously with the collection of precipitation samples from eight sites during a January 2001 storm event. The highest concentrations of diazinon occurred during the storm periods for all 16 sites, and the highest concentrations of chlorpyrifos occurred during weekly nonstorm sampling for the river sites and during the January storm period for the urban storm drain and precipitation sites. A total of 60 samples (41 from river sites, 10 from precipitation sites, and 9 from the storm drain site) had diazinon concentrations greater than 0.08 ?g/L, the concentration being considered by the California Department of Fish and Game as its criterion maximum concentration for the protection of aquatic habitats. A total of 18 samples (2 from river sites, 9 from precipitation sites, and 7 from the storm drain site) exceeded the equivalent California Department of Fish and Game guideline of 0.02 ?g/L for chlorpyrifos. The total diazinon load in the San Joaquin River near Vernalis during January and February 2001 was 23.8 pounds active ingredient; of this amount, 16.9 pounds active ingredient were transported by four storms, 1.06 pounds active ingredient were transported by nonstorm events, and 5.82 pounds active ingredient were considered to be baseline loads. The total chlorpyrifos load in the San Joaquin River near Vernalis during January and February 2001 was 2.17 pounds active ingredient; of this amount, 0.702 pound active ingredient was transported during the four storms, and 1.47 pounds active ingredient were considered as baseline load. The total January and February diazinon load in the San Joaquin River near Vernalis was 0.27 percent of dormant application; the total January and February chlorpyrifos load was 0.02 percent of dormant application. The precipitation samples collected during the January 2001 storm event were analyzed for pesticides to evaluate their potential contribution to pesticide loads in the study area. When the average concentrations of diazinon and chlorpyrifos in the precipitation samples were compared with concentrations in urban storm runoff samples, 68 percent of the diazinon concentration in the runoff could be accounted for in the precipitation. Chlorpyrifos, however, had average precipitation concentrations that were 2.5 times higher than what was detected in the runoff. Although no firm conclusions can be made from one storm event, preliminary results indicate that pesticides in precipitation can significantly contribute to pesticide loads in storm runoff.

Remediation of Mercury-Contaminated Storm Sewer Sediments from the West End Mercury Area at the Y-12 National Security Complex in Oak Ridge, Tennessee - 12061

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tremaine, Diana; Douglas, Steven G.

2012-07-01

The Y-12 National Security Complex in Oak Ridge, TN has faced an ongoing challenge from mercury entrapped in soils beneath and adjacent to buildings, storm sewers, and process pipelines. Previous actions to reduce the quantity and/or mobilization of mercury-contaminated media have included plugging of building floor drains, cleaning of sediment and sludge from sumps, manholes, drain lines, and storm sewers, lining/relining of storm sewers and replacement of a portion of the storm sewer trunk line, re-routing and removal of process piping, and installation of the Central Mercury Treatment System to capture and treat contaminated sump water. Despite the success ofmore » these actions, mercury flux in the storm sewer out-falls that discharge to Upper East Fork Poplar Creek (UEFPC) continues to pose a threat to long-term water quality. A video camera survey of the storm sewer network revealed several sections of storm sewer that had large cracks, separations, swells, and accumulations of sediment/sludge and debris. The selected remedy was to clean and line the sections of storm sewer pipe that were determined to be primary contributors to the mercury flux in the storm sewer out-falls. The project, referred to as the West End Mercury Area (WEMA) Storm Sewer Remediation Project, included cleaning sediment and debris from over 2,460 meters of storm sewer pipe followed by the installation of nearly 366 meters of cure-in-place pipe (CIPP) liner. One of the greatest challenges to the success of this project was the high cost of disposal associated with the mercury-contaminated sludge and wastewater generated from the storm sewer cleaning process. A contractor designed and operated an on-site wastewater pre-treatment system that successfully reduced mercury levels in 191 cubic meters of sludge to levels that allowed it to be disposed at Nevada Nuclear Security Site (NNSS) disposal cell as a non-hazardous, low-level waste. The system was also effective at pre-treating over 1,514,000 liters of wastewater to levels that met the waste acceptance criteria for the on-site West End [wastewater] Treatment Facility (WETF). This paper describes the storm sewer cleaning and lining process and the methods used to process the mercury-contaminated sludge and wastewater, as well as several 'lessons learned' that would be relevant to any future projects involving storm sewer cleaning and debris remediation. (authors)« less

Drained coastal peatlands: A potential nitrogen source to marine ecosystems under prolonged drought and heavy storm events-A microcosm experiment.

PubMed

Wang, Hongjun; Richardson, Curtis J; Ho, Mengchi; Flanagan, Neal

2016-10-01

Over the past several decades there has been a massive increase in coastal eutrophication, which is often caused by increased runoff input of nitrogen from landscape alterations. Peatlands, covering 3% of land area, have stored about 12-21% of global soil organic nitrogen (12-20Pg N) around rivers, lakes and coasts over millennia and are now often drained and farmed. Their huge nitrogen pools may be released by intensified climate driven hydrologic events-prolonged droughts followed by heavy storms-and later transported to marine ecosystems. In this study, we collected peat monoliths from drained, natural, and restored coastal peatlands in the Southeastern U.S., and conducted a microcosm experiment simulating coupled prolonged-drought and storm events to (1) test whether storms could trigger a pulse of nitrogen export from drought-stressed peatlands and (2) assess how differentially hydrologic managements through shifting plant communities affect nitrogen export by combining an experiment of nitrogen release from litter. During the drought phase, we observed a significant temporal variation in net nitrogen mineralization rate (NMR). NMR spiked in the third month and then decreased rapidly. This pattern indicates that drought duration significantly affects nitrogen mineralization in peat. NMR in the drained site reached up to 490±110kgha(-1)year(-1), about 5 times higher than in the restored site. After the 14-month drought phase, we simulated a heavy storm by bringing peat monoliths to saturation. In the discharge waters, concentrations of total dissolved nitrogen in the monoliths from the drained site (72.7±16.3mgL(-1)) was about ten times as high as from the restored site. Our results indicate that previously drained peatlands under prolonged drought are a potent source of nitrogen export. Moreover, drought-induced plant community shifts to herbaceous plants substantially raise nitrogen release with lasting effects by altering litter quality in peatlands. Copyright © 2016 Elsevier B.V. All rights reserved.

Pesticides in storm runoff from agricultural and urban areas in the Tuolumne River basin in the vicinity of Modesto, California

USGS Publications Warehouse

Kratzer, Charles R.

1998-01-01

The occurrence, concentrations, and loads of dissolved pesticides in storm runoff were compared for two contrasting land uses in the Tuolumne River Basin, California, during two different winter storms: agricultural areas (February 1994) and the Modesto urban area (February 1995). Both storms followed the main application period of pesticides on dormant almond orchards. Eight samples of runoff from agricultural areas were collected from a Tuolumne River site, and 10 samples of runoff from urban areas were collected from five storm drains. All samples were analyzed for 46 pesticides. Six pesticides were detected in runoff from agricultural areas, and 15 pesticides were detected in runoff from urban areas. Chlorpyrifos, diazinon, dacthal (DCPA), metolachlor, and simazine were detected in almost every sample. Median concentrations were higher in the runoff from urban areas for all pesticides except napropamide and simazine. The greater occurrence and concentrations in storm drains is partly attributed to dilution of agricultural runoff by nonstorm base-flow in the Tuolumne River and by storm runoff from nonagricultural and nonurban land. In most cases, the occurrence and relative concentrations of pesticides found in storm runoff from agricultural and urban areas were related to reported pesticide application. Pesticide concentrations in runoff from agricultural areas were more variable during the storm hydrograph than were concentrations in runoff from urban areas. All peak pesticide concentrations in runoff from agricultural areas occurred during the rising limb of the storm hydrograph, whereas peak concentrations in the storm drains occurred at varying times during the storm hydrograph. Transport of pesticides from agricultural areas during the February 1994 storm exceeded transport from urban areas during the February 1995 storm for chlorpyrifos, diazinon, metolachlor, napropamide, and simazine. Transport of DCPA was about the same from agricultural and urban sources, and the main source of transport for the other pesticides could not be determined because of concentrations less than the method detection limit.

Evaluation of trench and slotted drain maintenance and cleaning : Phase 1 : final report.

DOT National Transportation Integrated Search

2017-03-01

Trench and slotted drains are increasingly being used by ODOT to remove storm water from the roadways. These drains have to be properly cleaned and maintained to prevent vehicles from hydroplaning, eliminate flooding and avoid premature roadway failu...

The Use of Stimulable Bioluminescence from Marine Dinoflagellates as a Means of Detecting Toxicity in the Marine Environment

DTIC Science & Technology

1993-04-01

measure the acute and sublethal effects of heavy metals ( tributyltin , copper, and zinc) and storm drain effluent on the light output from marine...heavy metals ( tributyltin , copper, and zinc) and storm drain effluent on the light output from marine bioluminescent dinoflagellates (Pyrocystis...pentahydrate and zinc sulfate heptahydrate (Aldrich Chemical Co.); tributyltin chloride (Aldrich Chemical Co.); American Society for Testing and Materials

A 24 h investigation of the hydrogeochemistry of baseflow and stormwater in an urban area impacted by mining: Butte, Montana

USGS Publications Warehouse

Gammons, Christopher H.; Shope, Christopher L.; Duaime, Terence E.

2005-01-01

Changes in water quality during a storm event were continuously monitored over a 24 h period at a single location along an urban stormwater drain in Butte, Montana. The Butte Metro Storm Drain (MSD) collects groundwater baseflow and stormwater draining Butte Hill, a densely populated site that has been severely impacted by 130 years of mining, milling, and smelting of copper-rich, polymetallic mineral deposits. On the afternoon of 26 June 2002, a heavy thunderstorm caused streamflow in the MSD to increase 100-fold, from 0·2 ft3 s−1 to more than 20 ft3 s−1. Hourly discharge and water quality data were collected before, during, and following the storm. The most significant finding was that the calculated loads (grams per hour) of both dissolved and particulate copper passing down the MSD increased more than 100-fold in the first hour following the storm, and remained elevated over baseline conditions for the remainder of the study period. Other metals, such as zinc, cadmium, and manganese, showed a decrease in load from pre-storm to post-storm conditions. In addition to the large flush of copper, loads of soluble phosphorus increased during the storm, whereas dissolved oxygen dropped to low levels (<2 mg l−1). These results show that infrequent storm events in Butte have the potential to generate large volumes of runoff that exceed Montana water quality standards for acute exposure of aquatic life to copper, as well as depressed levels of dissolved oxygen. This study has important implications to ongoing reclamation activities in the upper Clark Fork Superfund site, particularly with respect to management of storm flow, and may be applicable to other watersheds impacted by mining activities.

Modeling of coastal water contamination in Fortaleza (Northeastern Brazil).

PubMed

Pereira, S P; Rosman, P C C; Alvarez, C; Schetini, C A F; Souza, R O; Vieira, R H S F

2015-01-01

An important tool in environmental management projects and studies due to the complexity of environmental systems, environmental modeling makes it possible to integrate many variables and processes, thereby providing a dynamic view of systems. In this study the bacteriological quality of the coastal waters of Fortaleza (a state capital in Northeastern Brazil) was modeled considering multiple contamination sources. Using the software SisBaHiA, the dispersion of thermotolerant coliforms and Escherichia coli from three sources of contamination (local rivers, storm drains and submarine outfall) was analyzed. The models took into account variations in bacterial decay due to solar radiation and other environmental factors. Fecal pollution discharged from rivers and storm drains is transported westward by coastal currents, contaminating strips of beach water to the left of each storm drain or river. Exception to this condition only occurs on beaches protected by the breakwater of the harbor, where counterclockwise vortexes reverse this behavior. The results of the models were consistent with field measurements taken during the dry and the rainy season. Our results show that the submarine outfall plume was over 2 km from the nearest beach. The storm drains and the Maceió stream are the main factors responsible for the poor water quality on the waterfront of Fortaleza. The depollution of these sources would generate considerable social, health and economic gains for the region.

Contrasting nitrogen and phosphorus budgets in urban watersheds and implications for managing urban water pollution

PubMed Central

Janke, Benjamin D.; Nidzgorski, Daniel A.; Millet, Dylan B.; Baker, Lawrence A.

2017-01-01

Managing excess nutrients remains a major obstacle to improving ecosystem service benefits of urban waters. To inform more ecologically based landscape nutrient management, we compared watershed inputs, outputs, and retention for nitrogen (N) and phosphorus (P) in seven subwatersheds of the Mississippi River in St. Paul, Minnesota. Lawn fertilizer and pet waste dominated N and P inputs, respectively, underscoring the importance of household actions in influencing urban watershed nutrient budgets. Watersheds retained only 22% of net P inputs versus 80% of net N inputs (watershed area-weighted averages, where net inputs equal inputs minus biomass removal) despite relatively low P inputs. In contrast to many nonurban watersheds that exhibit high P retention, these urban watersheds have high street density that enhanced transport of P-rich materials from landscapes to stormwater. High P exports in storm drainage networks and yard waste resulted in net P losses in some watersheds. Comparisons of the N/P stoichiometry of net inputs versus storm drain exports implicated denitrification or leaching to groundwater as a likely fate for retained N. Thus, these urban watersheds exported high quantities of N and P, but via contrasting pathways: P was exported primarily via stormwater runoff, contributing to surface water degradation, whereas N losses additionally contribute to groundwater pollution. Consequently, N management and P management require different strategies, with N management focusing on reducing watershed inputs and P management also focusing on reducing P movement from vegetated landscapes to streets and storm drains. PMID:28373560

Monitoring coastal marine waters for spore-forming bacteria of faecal and soil origin to determine point from non-point source pollution.

PubMed

Fujioka, R S

2001-01-01

The US Environmental Protection Agency (USEPA) and the World Health Organization (WHO) have established recreational water quality standards limiting the concentrations of faecal indicator bacteria (faecal coliform, E. coli, enterococci) to ensure that these waters are safe for swimming. In the application of these hygienic water quality standards, it is assumed that there are no significant environmental sources of these faecal indicator bacteria which are unrelated to direct faecal contamination. However, we previously reported that these faecal indicator bacteria are able to grow in the soil environment of humid tropical island environments such as Hawaii and Guam and are transported at high concentrations into streams and storm drains by rain. Thus, streams and storm drains in Hawaii contain consistently high concentrations of faecal indicator bacteria which routinely exceed the EPA and WHO recreational water quality standards. Since, streams and storm drains eventually flow out to coastal marine waters, we hypothesize that all the coastal beaches which receive run-off from streams and storm drains will contain elevated concentrations of faecal indicator bacteria. To test this hypothesis, we monitored the coastal waters at four beaches known to receive water from stream or storm drains for salinity, turbidity, and used the two faecal indicator bacteria (E. coli, enterococci) to establish recreational water quality standards. To determine if these coastal waters are contaminated with non-point source pollution (streams) or with point source pollution (sewage effluent), these same water samples were also assayed for spore-forming bacteria of faecal origin (Cl. perfringens) and of soil origin (Bacillus species). Using this monitoring strategy it was possible to determine when coastal marine waters were contaminated with non-point source pollution and when coastal waters were contaminated with point source pollution. The results of this study are most likely applicable to all countries in the warm and humid region of the world.

Solute load concentrations in some streams in the Upper Osun and Owena drainage basins, central western Nigeria

NASA Astrophysics Data System (ADS)

Jeje, L. K.; Ogunkoya, O. O.; Oluwatimilehin, J. M.

1999-12-01

The solute load dynamics of 12 third-order streams in central western Nigeria are presented, during storm and non-storm runoff events. The relevance of the Walling and Foster model for explaining storm period solute load dynamics in the humid tropical environment was assessed and it was found that this model was generally applicable to the study area. Exceptions appear to be streams draining settlements and/or farms where fertilizers are applied heavily. The solute load ranged from 5 mg l -1 to 580 mg l -1 with streams draining basins with tree-crop plantations ( Theobroma cacao, Cola sp.) as the dominant land cover having the highest solute load.

Basin-Scale Reconstruction of Flood Characteristics in a Small Urban Waterhsed

NASA Astrophysics Data System (ADS)

Miller, A. J.; Smith, J. A.; Baeck, M. L.

2006-05-01

Intense short-duration summer thunderstorms are primarily responsible for the occurrence of extreme floods in small, highly urban watersheds. In these systems hydrologic response is rapid and the role of urban infrastructure (impervious cover, storm drain networks, stormwater retention facilities, engineered channels, road embankments, bridges and culverts, and floodplain fill and regrading) has potentially important consequences for runoff generation and for flood-wave propagation. The occurrence of even a single well- documented extreme event provides an opportunity to improve our understanding of the relationships between temporal and spatial patterns of precipitation, natural and anthropogenic landscape features, and the dynamics of flood behavior. We report on combined field and modeling studies of a record flood (Qpk ~ 250 m3s-1) that occurred on 7 July 2004 in the 14.3 km2 Dead Run watershed in suburban Baltimore, Maryland. Flood peaks were reconstructed for nine locations in the watershed and streamflow hydrographs were derived for four locations where complete or partial stage records were recovered; these were compared with precipitation mass-balance estimates using bias-corrected radar rainfall data in order to examine the spatial pattern of runoff ratios, lag times, and cumulative properties of the flood wave as it advanced downstream. Flood behavior in part reflects the role of capacity constraints in the storm drain network and of ponding and storage of overbank flow by physical barriers such as road embankments and culverts. The results can be used to improve predictions of flood response to other hydrometeorological events and provide insight on sensitivity of flood behavior to patterns of urban development and infrastructure.

Postwildfire debris-flow hazard assessment of the area burned by the 2013 West Fork Fire Complex, southwestern Colorado

USGS Publications Warehouse

Verdin, Kristine L.; Dupree, Jean A.; Stevens, Michael R.

2013-01-01

This report presents a preliminary emergency assessment of the debris-flow hazards from drainage basins burned by the 2013 West Fork Fire Complex near South Fork in southwestern Colorado. Empirical models derived from statistical evaluation of data collected from recently burned basins throughout the intermountain western United States were used to estimate the probability of debris-flow occurrence, potential volume of debris flows, and the combined debris-flow hazard ranking along the drainage network within and just downstream from the burned area, and to estimate the same for 54 drainage basins of interest within the perimeter of the burned area. Input data for the debris-flow models included topographic variables, soil characteristics, burn severity, and rainfall totals and intensities for a (1) 2-year-recurrence, 1-hour-duration rainfall, referred to as a 2-year storm; (2) 10-year-recurrence, 1-hour-duration rainfall, referred to as a 10-year storm; and (3) 25-year-recurrence, 1-hour-duration rainfall, referred to as a 25-year storm. Estimated debris-flow probabilities at the pour points of the 54 drainage basins of interest ranged from less than 1 to 65 percent in response to the 2-year storm; from 1 to 77 percent in response to the 10-year storm; and from 1 to 83 percent in response to the 25-year storm. Twelve of the 54 drainage basins of interest have a 30-percent probability or greater of producing a debris flow in response to the 25-year storm. Estimated debris-flow volumes for all rainfalls modeled range from a low of 2,400 cubic meters to a high of greater than 100,000 cubic meters. Estimated debris-flow volumes increase with basin size and distance along the drainage network, but some smaller drainages also were predicted to produce substantial debris flows. One of the 54 drainage basins of interest had the highest combined hazard ranking, while 9 other basins had the second highest combined hazard ranking. Of these 10 basins with the 2 highest combined hazard rankings, 7 basins had predicted debris-flow volumes exceeding 100,000 cubic meters, while 3 had predicted probabilities of debris flows exceeding 60 percent. The 10 basins with high combined hazard ranking include 3 tributaries in the headwaters of Trout Creek, four tributaries to the West Fork San Juan River, Hope Creek draining toward a county road on the eastern edge of the burn, Lake Fork draining to U.S. Highway 160, and Leopard Creek on the northern edge of the burn. The probabilities and volumes for the modeled storms indicate a potential for debris-flow impacts on structures, reservoirs, roads, bridges, and culverts located within and immediately downstream from the burned area. U.S. Highway 160, on the eastern edge of the burn area, also is susceptible to impacts from debris flows.

Microcomputer software for storm drain hydraulic gradeline computation.

DOT National Transportation Integrated Search

1987-01-01

A microcomputer software module was developed for the computation of hydraulic gradeline in storm sewer systems. The computer module has been attached to the program '"HYDRA", which is being adopted by the FHWA organized Pooled Fund Study. on Integra...

Rainfall, Discharge, and Water-Quality Data During Stormwater Monitoring, July 1, 2007, to June 30, 2008; Halawa Stream Drainage Basin and the H-1 Storm Drain, Oahu, Hawaii

USGS Publications Warehouse

Presley, Todd K.; Jamison, Marcael T.J.; Young, Stacie T.M.

2008-01-01

Storm runoff water-quality samples were collected as part of the State of Hawaii Department of Transportation Stormwater Monitoring Program. The program is designed to assess the effects of highway runoff and urban runoff on Halawa Stream and to assess the effects from the H-1 storm drain on Manoa Stream. For this program, rainfall data were collected at three stations, continuous discharge data at four stations, and water-quality data at six stations, which include the four continuous discharge stations. This report summarizes rainfall, discharge, and water-quality data collected between July 1, 2007, and June 30, 2008. A total of 16 environmental samples were collected over two storms during July 1, 2007, to June 30, 2008, within the Halawa Stream drainage area. Samples were analyzed for total suspended solids, total dissolved solids, nutrients, chemical oxygen demand, and selected trace metals (cadmium, chromium, copper, lead, and zinc). Additionally, grab samples were analyzed for oil and grease, total petroleum hydrocarbons, fecal coliform, and biological oxygen demand. Some samples were analyzed for only a partial list of these analytes because an insufficient volume of sample was collected by the automatic samplers. Three additional quality-assurance/quality-control samples were collected concurrently with the storm samples. A total of 16 environmental samples were collected over four storms during July 1, 2007, to June 30, 2008 at the H-1 Storm Drain. All samples at this site were collected using an automatic sampler. Samples generally were analyzed for total suspended solids, nutrients, chemical oxygen demand, oil and grease, total petroleum hydrocarbons, and selected trace metals (cadmium, chromium, copper, lead, nickel, and zinc), although some samples were analyzed for only a partial list of these analytes. During the storm of January 29, 2008, 10 discrete samples were collected. Varying constituent concentrations were detected for the samples collected at different times during this storm event. Two quality-assurance/quality-control samples were collected concurrently with the storm samples. Three additional quality-assurance/quality-control samples were collected during routine sampler maintenance to check the effectiveness of equipment-cleaning procedures.

Hydrogen sulfide removal from sediment and water in box culverts/storm drains by iron-based granules.

PubMed

Sun, J L; Shang, C; Kikkert, G A

2013-01-01

A renewable granular iron-based technology for hydrogen sulfide removal from sediment and water in box culverts and storm drains is discussed. Iron granules, including granular ferric hydroxide (GFH), granular ferric oxide (GFO) and rusted waste iron crusts (RWIC) embedded in the sediment phase removed aqueous hydrogen sulfide formed from sedimentary biological sulfate reduction. The exhausted iron granules were exposed to dissolved oxygen and this regeneration process recovered the sulfide removal capacities of the granules. The recovery is likely attributable to the oxidation of the ferrous iron precipitates film and the formation of new reactive ferric iron surface sites on the iron granules and sand particles. GFH and RWIC showed larger sulfide removal capacities in the sediment phase than GFO, likely due to the less ordered crystal structures on their surfaces. This study demonstrates that the iron granules are able to remove hydrogen sulfide from sediment and water in box culverts and storm drains and they have the potential to be regenerated and reused by contacting with dissolved oxygen.

Rainfall, Discharge, and Water-Quality Data During Stormwater Monitoring, July 1, 2008, to June 30, 2009 - Halawa Stream Drainage Basin and the H-1 Storm Drain, Oahu, Hawaii

USGS Publications Warehouse

Presley, Todd K.; Jamison, Marcael T.J.

2009-01-01

Storm runoff water-quality samples were collected as part of the State of Hawaii Department of Transportation Stormwater Monitoring Program. The program is designed to assess the effects of highway runoff and urban runoff on Halawa Stream, and to assess the effects from the H-1 storm drain on Manoa Stream. For this program, rainfall data were collected at three stations, continuous discharge data at five stations, and water-quality data at six stations, which include the five continuous discharge stations. This report summarizes rainfall, discharge, and water-quality data collected between July 1, 2008, and June 30, 2009. Within the Halawa Stream drainage area, three storms (October 25 and December 11, 2008, and February 3, 2009) were sampled during July 1, 2008, to June 30, 2009. A total of 43 environmental samples were collected during these three storms. During the storm of October 25, 2009, 31 samples were collected and analyzed individually for metals only. The other 12 samples from the other two storms were analyzed for some or all of the following analytes: total suspended solids, total dissolved solids, nutrients, chemical oxygen demand, and selected trace metals (cadmium, chromium, copper, lead, and zinc). Additionally, grab samples were analyzed for some or all of the following analytes: oil and grease, total petroleum hydrocarbons, fecal coliform, and biological oxygen demand. Some grab and composite samples were analyzed for only a partial list of these analytes, either because samples could not be delivered to the laboratory in a timely manner, or an insufficient volume of sample was collected by the automatic samplers. Two quality-assurance/quality-control samples were collected after cleaning automatic sampler lines to verify that the sampling lines were not contaminated. Four environmental samples were collected at the H-1 Storm Drain during July 1, 2008, to June 30, 2009. An oil and grease sample and a composite sample were collected during the storm on November 15, 2008, and two composite samples were collected during the January 11, 2009, storm. All samples at this site were collected using an automatic sampler. Samples were analyzed for some or all of the following analytes: total suspended solids, nutrients, oil and grease, total petroleum hydrocarbons, and selected trace metals (cadmium, chromium, copper, lead, nickel, and zinc). One qualityassurance/quality-control sample was collected after cleaning automatic sampler lines to verify that the sampling lines were not contaminated. During the storm of January 11, 2009, the two composite samples collected at H-1 Storm Drain were collected about three hours apart. Higher constituent concentrations were detected in the first 2 composite sample relative to the second composite sample, although the average discharge was higher during the period when the second sample was collected.

Tile drainage as karst: Conduit flow and diffuse flow in a tile-drained watershed

USGS Publications Warehouse

Schilling, K.E.; Helmers, M.

2008-01-01

The similarity of tiled-drained watersheds to karst drainage basins can be used to improve understanding of watershed-scale nutrient losses from subsurface tile drainage networks. In this study, short-term variations in discharge and chemistry were examined from a tile outlet collecting subsurface tile flow from a 963 ha agricultural watershed. Study objectives were to apply analytical techniques from karst springs to tile discharge to evaluate water sources and estimate the loads of agricultural pollutants discharged from the tile with conduit, intermediate and diffuse flow regimes. A two-member mixing model using nitrate, chloride and specific conductance was used to distinguish rainwater versus groundwater inputs. Results indicated that groundwater comprised 75% of the discharge for a three-day storm period and rainwater was primarily concentrated during the hydrograph peak. A contrasting pattern of solute concentrations and export loads was observed in tile flow. During base flow periods, tile flow consisted of diffuse flow from groundwater sources and contained elevated levels of nitrate, chloride and specific conductance. During storm events, suspended solids and pollutants adhered to soil surfaces (phosphorus, ammonium and organic nitrogen) were concentrated and discharged during the rapid, conduit flow portion of the hydrograph. During a three-day period, conduit flow occurred for 5.6% of the time but accounted for 16.5% of the total flow. Nitrate and chloride were delivered primarily with diffuse flow (more than 70%), whereas 80-94% of total suspended sediment, phosphorus and ammonium were exported with conduit and intermediate flow regimes. Understanding the water sources contributing to tile drainage and the manner by which pollutant discharge occurs from these systems (conduit, intermediate or diffuse flow) may be useful for designing, implementing and evaluating non-point source reduction strategies in tile-drained landscapes. ?? 2007 Elsevier B.V. All rights reserved.

LAND USE AND SEASONAL EFFECTS ON URBAN STORMWATER RUNOFF MICROORGANISM CONCENTRATIONS

EPA Science Inventory

Stormwater samples collected from storm sewers draining small municipal separate storm sewer systems shown to be free of cross connections within an urban watershed dominated by a single land use were analyzed for pathogens (Pseudomonas aeruginosa and Staphylococcus aureus) and i...

EFFECTS OF LAND USE AND SEASON ON MICROORGANISM CONCENTRATIONS IN URBAN STORMWATER RUNOFF

EPA Science Inventory

This study investigated differences in pathogen and indicator organism concentrations in stormwater runoff between different urban land uses and seasons. Stormwater samples collected from storm sewers draining small municipal separate storm sewer systems shown to be free of cros...

Using Automatic Control Approach In Detention Storages For Storm Water Management In An Urban Watershed

NASA Astrophysics Data System (ADS)

Goyal, A.; Yadav, H.; Tyagi, H.; Gosain, A. K.; Khosa, R.

2017-12-01

Increased imperviousness due to rapid urbanization have changed the urban hydrological cycle. As watersheds are urbanized, infiltration and groundwater recharge have decreased, surface runoff hydrograph shows higher peak indicating large volumes of surface runoff in lesser time durations. The ultimate panacea is to reduce the peak of hydrograph or increase the retention time of surface flow. SWMM is widely used hydrologic and hydraulic software which helps to simulate the urban storm water management with the provision to apply different techniques to prevent flooding. A model was setup to simulate the surface runoff and channel flow in a small urban catchment. It provides the temporal and spatial information of flooding in a catchment. Incorporating the detention storages in the drainage network helps achieve reduced flooding. Detention storages provided with predefined algorithms were for controlling the pluvial flooding in urban watersheds. The algorithm based on control theory, automated the functioning of detention storages ensuring that the storages become active on occurrence of flood in the storm water drains and shuts down when flooding is over. Detention storages can be implemented either at source or at several downstream control points. The proposed piece of work helps to mitigate the wastage of rainfall water, achieve desirable groundwater and attain a controlled urban storm water management system.

The legacy of lead (Pb) in fluvial bed sediments of an urban drainage basin, Oahu, Hawaii.

PubMed

Hotton, Veronica K; Sutherland, Ross A

2016-03-01

The study of fluvial bed sediments is essential for deciphering the impact of anthropogenic activities on water quality and drainage basin integrity. In this study, a systematic sampling design was employed to characterize the spatial variation of lead (Pb) concentrations in bed sediment of urban streams in the Palolo drainage basin, southeastern Oahu, Hawaii. Potentially bioavailable Pb was assessed with a dilute 0.5 N HCl extraction of the <63 μm grain-size fraction from the upper bed sediment layer of 169 samples from Palolo, Pukele, and Waiomao streams. Contamination of bed sediments was associated with the direct transport of legacy Pb from the leaded gasoline era to stream channels via a dense network of storm drains linked to road surfaces throughout the basin. The Palolo Stream had the highest median Pb concentration (134 mg/kg), and the greatest road and storm drain densities, the greatest population, and the most vehicle numbers. Lower median Pb concentrations were associated with the less impacted Pukele Stream (24 mg/kg), and Waiomao Stream (7 mg/kg). The median Pb enrichment ratio values followed the sequence of Palolo (68) > Pukele (19) > Waiomao (8). Comparisons to sediment quality guidelines and potential toxicity estimates using a logistic regression model (LRM) indicated a significant potential risk of Palolo Stream bed sediments to bottom-dwelling organisms.

Canine scent detection and microbial source tracking of human waste contamination in storm drains.

PubMed

Van De Werfhorst, Laurie C; Murray, Jill L S; Reynolds, Scott; Reynolds, Karen; Holden, Patricia A

2014-06-01

Human fecal contamination of surface waters and drains is difficult to diagnose. DNA-based and chemical analyses of water samples can be used to specifically quantify human waste contamination, but their expense precludes routine use. We evaluated canine scent tracking, using two dogs trained to respond to the scent of municipal wastewater, as a field approach for surveying human fecal contamination. Fecal indicator bacteria, as well as DNA-based and chemical markers of human waste, were analyzed in waters sampled from canine scent-evaluated sites (urban storm drains and creeks). In the field, the dogs responded positively (70% and 100%) at sites for which sampled waters were then confirmed as contaminated with human waste. When both dogs indicated a negative response, human waste markers were absent. Overall, canine scent tracking appears useful for prioritizing sampling sites for which DNA-based and similarly expensive assays can confirm and quantify human waste contamination.

Effect of tillage on macropore flow and phosphorus transport to tile drains

USDA-ARS?s Scientific Manuscript database

Elevated phosphorus (P) concentrations in subsurface drainage water are thought to be the result of P bypassing the soil matrix via macropore flow. The objectives of this study were to quantify event water delivery to tile drains via macropore flow paths during storm events and to determine the effe...

Changes in the character of DOC in streams during storms in two Midwestern watersheds with contrasting land uses

USGS Publications Warehouse

Vidon, P.; Wagner, L.E.; Soyeux, E.

2008-01-01

Dissolved organic carbon (DOC) dynamics in streams is important, yet few studies focus on DOC dynamics in Midwestern streams during storms. In this study, stream DOC dynamics during storms in two Midwestern watersheds with contrasting land uses, the change in character of stream DOC during storms, and the usability of DOC as a hydrologic tracer in artificially drained landscapes of the Midwest are investigated. Major cation/DOC concentrations, and DOC specific UV absorbance (SUVA) and fluorescence index (FI) were monitored at 2-4 h intervals during three spring storms. Although DOC is less aromatic in the mixed land use watershed than in the agricultural watershed, land use has little impact on stream DOC concentration during storms. For both watersheds, DOC concentration follows discharge, and SUVA and FI values indicate an increase in stream DOC aromaticity and lignin content during storms. The comparison of DOC/major cation flushing dynamics indicates that DOC is mainly exported via overland flow/macropore flow. In both watersheds, the increase in DOC concentration in the streams during storms corresponds to a shift in the source of DOC from DOC originating from mineral soil layers of the soil profile at baseflow, to DOC originating from surficial soil layers richer in aromatic substances and lignin during storms. Results also suggest that DOC, SUVA and FI could be used as hydrologic tracers in artificially drained landscapes of the Midwest. These results underscore the importance of sampling streams for DOC during high flow periods in order to understand the fate of DOC in streams. ?? 2008 Springer Science+Business Media B.V.

A novel approach to model dynamic flow interactions between storm sewer system and overland surface for different land covers in urban areas

NASA Astrophysics Data System (ADS)

Chang, Tsang-Jung; Wang, Chia-Ho; Chen, Albert S.

2015-05-01

In this study, we developed a novel approach to simulate dynamic flow interactions between storm sewers and overland surface for different land covers in urban areas. The proposed approach couples the one-dimensional (1D) sewer flow model (SFM) and the two-dimensional (2D) overland flow model (OFM) with different techniques depending on the land cover type of the study areas. For roads, pavements, plazas, and so forth where rainfall becomes surface runoff before entering the sewer system, the rainfall-runoff process is simulated directly in the 2D OFM, and the runoff is drained to the sewer network via inlets, which is regarded as the input to 1D SFM. For green areas on which rainfall falls into the permeable ground surface and the generated direct runoff traverses terrain, the deduction rate is applied to the rainfall for reflecting the soil infiltration in the 2D OFM. For flat building roofs with drainage facilities allowing rainfall to drain directly from the roof to sewer networks, the rainfall-runoff process is simulated using the hydrological module in the 1D SFM where no rainfall is applied to these areas in the 2D OFM. The 1D SFM is used for hydraulic simulations in the sewer network. Where the flow in the drainage network exceeds its capacity, a surcharge occurs and water may spill onto the ground surface if the pressure head in a manhole exceeds the ground elevation. The overflow discharge from the sewer system is calculated by the 1D SFM and considered a point source in the 2D OFM. The overland flow will return into the sewer network when it reaches an inlet that connects to an un-surcharged manhole. In this case, the inlet is considered as a point sink in the 2D OFM and an inflow to a manhole in the 1D SFM. The proposed approach was compared to other five urban flood modelling techniques with four rainfall events that had previously recorded inundation areas. The merits and drawbacks of each modelling technique were compared and discussed. Based on the simulated results, the proposed approach was found to simulate floodings closer to the survey records than other approaches because the physical rainfall-runoff phenomena in urban environment were better reflected.

Evaluation of the novel crAssphage marker for sewage pollution tracking in storm drain outfalls in Tampa, Florida.

PubMed

Ahmed, Warish; Lobos, Aldo; Senkbeil, Jacob; Peraud, Jayme; Gallard, Javier; Harwood, Valerie J

2017-12-24

CrAssphage are recently-discovered DNA bacteriophages that are prevalent and abundant in human feces and sewage. We assessed the performance characteristics of a crAssphage quantitative PCR (qPCR) assay for quantifying sewage impacts in stormwater and surface water in subtropical Tampa, Florida. The mean concentrations of crAssphage in untreated sewage ranged from 9.08 to 9.98 log 10 gene copies/L. Specificity was 0.927 against 83 non-human fecal reference samples and the sensitivity was 1.0. Cross-reactivity was observed in DNA extracted from soiled poultry litter but the concentrations were substantially lower than untreated sewage. The presence of the crAssphage marker was monitored in water samples from storm drain outfalls during dry and wet weather conditions in Tampa, Florida. In dry weather conditions, 41.6% of storm drain outfalls samples were positive for the crAssphage marker and the concentrations ranged from 3.60 to 4.65 log 10 gene copies/L of water. After a significant rain event, 66.6% of stormwater outlet samples were positive for the crAssphage marker and the concentration ranged from 3.62 to 4.91 log 10 gene copies/L of water. The presence of the most commonly used Bacteroides HF183 marker in storm drain outfalls was also tested along with the crAssphage. Thirteen samples (55%) were either positive (i.e., both markers were present) or negative (i.e., both markers were absent) for both the markers. Due to the observed cross-reactivity of this marker with DNA extracted from poultry litter samples, it is recommended that this marker should be used in conjunction with additional markers such as HF183. Our data indicate that the crAssphage marker is highly sensitive to sewage, is adequately specific, and will be a valuable addition to the MST toolbox. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Occurrence and Transport of Agricultural Chemicals in Leary Weber Ditch Basin, Hancock County, Indiana, 2003-04

USGS Publications Warehouse

Baker, Nancy T.; Stone, Wesley W.; Wilson, John T.; Meyer, Michael T.

2006-01-01

Leary Weber Ditch Basin, Hancock County, Indiana, is one of seven first-order basins selected from across the United States as part of the Agricultural Chemicals: Source, Transport, and Fate study conducted by the National Water-Quality Assessment Program of the U.S. Geological Survey. The nationwide study was designed to increase the understanding of the links between the sources of water and agricultural chemicals (nutrients and pesticides) and the transport and fate of these chemicals through the environment. Agricultural chemicals were detected in Leary Weber Ditch and in every associated hydrologic compartment sampled during 2003 and 2004. Pesticides were detected more frequently in samples collected from overland flow and from the ditch itself and less frequently in ground-water samples. The lowest concentrations of pesticides and nutrients were detected in samples of rain, soil water, and ground water. The highest concentrations of pesticides and nutrients were detected in samples of tile-drain water, overland flow, and water from Leary Weber Ditch. Samples collected from the tile drain, overland flow and Leary Weber Ditch soon after chemical applications to the fields and coincident with rainfall and increased streamflow had higher concentrations of pesticides and nutrients than samples collected a longer time after the chemicals were applied. A mass-balance mixing analysis based on potassium concentrations indicated that tile drains are the primary contributor of water to Leary Weber Ditch, but overland flow is also an important contributor during periods of high-intensity rainfall. When maximum rainfall intensity was 0.5 inches per hour or lower, overland flow contributed about 10 percent and tile drains contributed about 90 percent of the flow to Leary Weber Ditch. When maximum rainfall intensity was 0.75 inches per hour or greater, overland flow contributed about 40 percent and tile drains contributed about 60 percent of the flow to the ditch. Ground-water flow to Leary Weber Ditch was negligible. Tile drains are an important agricultural-chemical transport path to Leary Weber Ditch, based on the hydrologic contributions of overland flow and tile drains to the ditch. Overland flow is also an important agricultural-chemical transport pathway during high-intensity rainfall; however, storms with high-intensity rainfall are sporadic throughout the year. Tile drains and the soil water moving to the tile drains are the primary transport pathway for agricultural-chemical transport to Leary Weber Ditch during most storms as well as between storms.

Post-fire debris-flow hazard assessment of the area burned by the 2013 Beaver Creek Fire near Hailey, central Idaho

USGS Publications Warehouse

Skinner, Kenneth D.

2013-01-01

A preliminary hazard assessment was developed for debris-flow hazards in the 465 square-kilometer (115,000 acres) area burned by the 2013 Beaver Creek fire near Hailey in central Idaho. The burn area covers all or part of six watersheds and selected basins draining to the Big Wood River and is at risk of substantial post-fire erosion, such as that caused by debris flows. Empirical models derived from statistical evaluation of data collected from recently burned basins throughout the Intermountain Region in Western United States were used to estimate the probability of debris-flow occurrence, potential volume of debris flows, and the combined debris-flow hazard ranking along the drainage network within the burn area and to estimate the same for analyzed drainage basins within the burn area. Input data for the empirical models included topographic parameters, soil characteristics, burn severity, and rainfall totals and intensities for a (1) 2-year-recurrence, 1-hour-duration rainfall, referred to as a 2-year storm (13 mm); (2) 10-year-recurrence, 1-hour-duration rainfall, referred to as a 10-year storm (19 mm); and (3) 25-year-recurrence, 1-hour-duration rainfall, referred to as a 25-year storm (22 mm). Estimated debris-flow probabilities for drainage basins upstream of 130 selected basin outlets ranged from less than 1 to 78 percent with the probabilities increasing with each increase in storm magnitude. Probabilities were high in three of the six watersheds. For the 25-year storm, probabilities were greater than 60 percent for 11 basin outlets and ranged from 50 to 60 percent for an additional 12 basin outlets. Probability estimates for stream segments within the drainage network can vary within a basin. For the 25-year storm, probabilities for stream segments within 33 basins were higher than the basin outlet, emphasizing the importance of evaluating the drainage network as well as basin outlets. Estimated debris-flow volumes for the three modeled storms range from a minimal debris flow volume of 10 cubic meters [m3]) to greater than 100,000 m3. Estimated debris-flow volumes increased with basin size and distance downstream. For the 25-year storm, estimated debris-flow volumes were greater than 100,000 m3 for 4 basins and between 50,000 and 100,000 m3 for 10 basins. The debris-flow hazard rankings did not result in the highest hazard ranking of 5, indicating that none of the basins had a high probability of debris-flow occurrence and a high debris-flow volume estimate. The hazard ranking was 4 for one basin using the 10-year-recurrence storm model and for three basins using the 25-year-recurrence storm model. The maps presented herein may be used to prioritize areas where post-wildfire remediation efforts should take place within the 2- to 3-year period of increased erosional vulnerability.

Coupled 1-D sewer and street networks and 2-D flooding model to rapidly evaluate surface inundation

NASA Astrophysics Data System (ADS)

Kao, Hong-Ming; Hsu, Hao-Ming

2017-04-01

Flash floods have occurred frequently in the urban areas around the world and cause the infrastructure and people living to expose continuously in the high risk level of pluvial flooding. According to historical surveys, the major reasons of severe surface inundations in the urban areas can be attributed to heavy rainfall in the short time and/or drainage system failure. In order to obtain real-time flood forecasting with high accuracy and less uncertainty, an appropriate system for predicting floods is necessary. For the reason, this study coupled 1-D sewer and street networks and 2-D flooding model as an operational modelling system for rapidly evaluating surface inundation. The proposed system is constructed by three significant components: (1) all the rainfall-runoff of a sub-catchment collected via gullies is simulated by the RUNOFF module of the Storm Water Management Model (SWMM); (2) and directly drained to the 1-D sewer and street networks via manholes as inflow discharges to conduct flow routing by using the EXTRAN module of SWMM; (3) after the 1-D simulations, the surcharges from manholes are considered as point sources in 2-D overland flow simulations that are executed by the WASH123D model. It can thus be used for urban flood modelling that reflects the rainfall-runoff processes, and the dynamic flow interactions between the storm sewer system and the ground surface in urban areas. In the present study, we adopted the Huwei Science and Technology Park, located in the south-western part of Taiwan, as the demonstration area because of its high industrial values. The region has an area about 1 km2 with approximately 1 km in both length and width. It is as isolated urban drainage area in which there is a complete sewer system that collects the runoff and drains to the detention pond. Based on the simulated results, the proposed modelling system was found that the simulated floods fit to the survey records because the physical rainfall-runoff phenomena in urban environment were better reflected. Keywords: SWMM, WASH123D, surface inundation, real-time.

Measuring fallout radionuclides to constrain the origin and the dynamics of suspended sediment in an agricultural drained catchment (Loire River basin, France)

NASA Astrophysics Data System (ADS)

Le Gall, Marion; Evrard, Olivier; Foucher, Anthony; Laceby, J. Patrick; Salvador-Blanes, Sébastien; Lefèvre, Irène; Cerdan, Olivier; Ayrault, Sophie

2015-04-01

Soil erosion reaches problematic levels in agricultural areas of Northwestern Europe where tile drains may accelerate sediment transfer to rivers. This supply of large quantities of fine sediment to the river network leads to the degradation of water quality by increasing water turbidity, filling reservoirs and transporting contaminants. Agricultural patterns and landscapes features have been largely modified by human activities during the last century. To investigate erosion and sediment transport in lowland drained areas, a small catchment, the Louroux (24 km²), located in the French Loire River basin was selected. In this catchment, channels have been reshaped and more than 220 tile drains outlets have been installed after World War II. As a result, soil erosion and sediment fluxes strongly increased. Sediment supply needs to be better understood by quantifying the contribution of sources and the residence times of particles within the catchment. To this end, a network of river monitoring stations was installed, and fallout radionuclides (Cs-137, excess Pb-210 and Be-7) were measured in rainwater (n=3), drain tile outlets (n=4), suspended sediment (n=15), soil surface (n=30) and channel bank samples (n=15) between January 2013 and February 2014. Cs-137 concentrations were used to quantify the contribution of surface vs. subsurface sources of sediment. Results show a clear dominance of particles originating from surface sources (99 ± 1%). Be-7 and excess Pb-210 concentrations and calculation of Be-7/excess Pb-210 ratios in rainfall and suspended sediment samples were used to estimate percentages of recently eroded sediment in rivers. The first erosive winter storm mainly exported sediment depleted in Be-7 that likely deposited on the riverbed during the previous months. Then, during the subsequent floods, sediment was directly eroded and exported to the catchment outlet. Our results show the added value of combining spatial and temporal tracers to characterize and quantify sources of sediment and particle transport processes within an agricultural catchment.

Occurrence and Transport of Diazinon in the Sacramento River and Selected Tributaries, California, during Two Winter Storms, January?February 2001

USGS Publications Warehouse

Dileanis, Peter D.; Brown, David L.; Knifong, Donna L.; Saleh, Dina

2003-01-01

Diazinon, an organophosphate insecticide, is applied as an orchard dormant spray in the Sacramento Valley during the winter months when the area receives most of its annual rainfall. During winter rainstorms that frequently follow dormant spray applications, some of the applied pesticide is transported in storm runoff to the Sacramento River and its tributaries. Diazinon is also used to control insect pests on residential and commercial properties in urban areas and is frequently detected in urban storm runoff draining into the Sacramento River system. Between January 24 and February 14, 2001, diazinon concentrations and loads were measured in the Sacramento River and selected tributaries during two winter storms that occurred after dormant spray applications were made to orchards in the Sacramento Valley. Water samples were collected at 21 sites that represented agricultural and urban inputs on a variety of scales, from small tributaries and drains representing local land use to main-stem river sites representing regional effects. Concentrations of diazinon ranged from below laboratory reporting levels to 1,380 nanograms per liter (ng/L), with a median of 55 ng/L during the first monitored storm and 26 ng/L during the second. The highest concentrations were observed in small channels draining predominantly agricultural land. About 26,000 pounds of diazinon were reported applied to agricultural land in the study area just before and during the monitoring period. About 0.2 percent of the applied insecticide appeared to be transported to the lower Sacramento River during that period. The source of about one third of the total load measured in the lower Sacramento River appears to be in the portion of the drainage basin upstream of the city of Colusa. About 12 percent of the diazinon load in the lower Sacramento River was transported from the Feather River Basin, which drains much of the mountainous eastern portions of the Sacramento River Basin. Diazinon use in the study area during the 2000?2001 dormant spray season continued a declining trend observed since 1993. The maximum concentrations of diazinon observed during the last 2 years of monitoring were lower than concentrations observed in previous years when larger amounts of diazinon had been applied as dormant sprays.

Flood of May 26-27, 1984 in Tulsa, Oklahoma

USGS Publications Warehouse

Bergman, DeRoy L.; Tortorelli, Robert L.

1988-01-01

The greatest flood disaster in the history of Tulsa, Oklahoma occurred during 8 hours from 2030 hours May 26 to 0430 hours May 27, 1984, as a result of intense rainfall centered over the metropolitan area. Storms of the magnitude that caused this flood are not uncommon to the southern great plains. Such storms are seldom documented in large urban areas. Total rainfall depth and rainfall distribution in the Tulsa metropolitan area during the May 26-27 storm were recorded by 16 recording rain gages. This report presents location of recording rain gages with corresponding rainfall histograms and mass curves, lines of equal rainfall depth (map A), and flood magnitudes and inundated areas of selected streams within the city (map B). The limits of the study areas (fig. 1) are the corporate boundaries of Tulsa, an area of about 185 square miles. Streams draining the city are: Dirty Butter, Coal, and Mingo Creeks which drain northward into Bird Creek along the northern boundary of the city; and Cherry, Crow, Harlow, Joe Haikey, Fry, Vensel, Fred, and Mooser Creeks which flow into the Arkansas River along the southern part of the city. Flooding along Haikey, Fry, Fred, Vensel, and Mooser Creeks was not documented for this report. The Arkansas River is regulated by Keystone Dam upstream from Tulsa (fig. 1). The Arkansas River remained below flood stage during the storm. Flooded areas in Tulsa (map B) were delineated on the topographic maps using flood profiles based on surveys of high-water marks identified immediately after the flood. The flood boundaries show the limits of stream flooding. Additional areas flooded because of overfilled storm drains or by sheet runoff are not shown in this report. Data presented in this report, including rainfall duration and frequency, and flood discharges and elevations, provide city officials and consultants a technical basis for making flood-plain management decisions.

Tracking nonpoint source nitrogen pollution in human-impacted watersheds

USGS Publications Warehouse

Kaushal, Sujay S.; Groffman, Peter M; Band, Lawrence; Elliott, Emily M.; Shields, Catherine A.; Kendall, Carol

2011-01-01

Nonpoint source nitrogen (N) pollution is a leading contributor to U.S. water quality impairments. We combined watershed N mass balances and stable isotopes to investigate fate and transport of nonpoint N in forest, agricultural, and urbanized watersheds at the Baltimore Long-Term Ecological Research site. Annual N retention was 55%, 68%, and 82% for agricultural, suburban, and forest watersheds, respectively. Analysis of δ15N-NO3–, and δ18O-NO3– indicated wastewater was an important nitrate source in urbanized streams during baseflow. Negative correlations between δ15N-NO3– and δ18O-NO3– in urban watersheds indicated mixing between atmospheric deposition and wastewater, and N source contributions changed with storm magnitude (atmospheric sources contributed ∼50% at peak storm N loads). Positive correlations between δ15N-NO3– and δ18O-NO3– in watersheds suggested denitrification was removing septic system and agriculturally derived N, but N from belowground leaking sewers was less susceptible to denitrification. N transformations were also observed in a storm drain (no natural drainage network) potentially due to organic carbon inputs. Overall, nonpoint sources such as atmospheric deposition, wastewater, and fertilizer showed different susceptibility to watershed N export. There were large changes in nitrate sources as a function of runoff, and anticipating source changes in response to climate and storms will be critical for managing nonpoint N pollution.

Environmental Assessment: Conestoga Reservoir Maintenance and Aquatic Habitat Rehabilitation Project Lancaster County, Nebraska

DTIC Science & Technology

2014-06-01

use and camping facilities, a boat launch and mooring area, sanitary facilities, and wells for drinking water at Conestoga Reservoir. Additional...gently sloping to very steep, well drained, loamy clay soils that formed in glacial till. The Sharpsburg series is a deep, moderately drained soil...Unfortunately, due to the number of potential sources ( sanitary wastewater, storm water, Conestoga Reservoir Rehabilitation Project U.S. Army Corps of

Storms and flooding in California in December 2005 and January 2006 - a preliminary assessment

USGS Publications Warehouse

Parrett, Charles; Hunrichs, Richard A.

2006-01-01

A series of storms beginning before Christmas 2005 and ending after New Year's Day 2006 produced significant runoff over much of northern California. The storms resulted in an estimated $300 million in damages and Federal disaster declarations in 10 counties. Several precipitation stations in the Sierra Nevada had precipitation totals greater than 20 inches for the period December 24 through January 3, and several stations in the Coastal Range had precipitation totals greater than 18 inches. The peak stream discharges resulting from the storms in the north coast area generally had recurrence intervals in the 10- to 25-year range, although the recurrence interval for peak discharge at one station on Sonoma Creek near Agua Caliente was greater than 100 years. In the San Francisco Bay area, peak discharges also generally had recurrence intervals in the 10- to 25-year range. Further south along the central coast and in southern California, peak discharges had smaller recurrence intervals, in the 2- to 5-year range. Upper Sacramento River tributaries draining from the west had peak flows with recurrence intervals in the 2- to 5-year range, whereas upper tributaries draining from the east side had recurrence intervals in the 5- to 10-year range. Further south, Sacramento River tributaries such as the Yuba and American Rivers had peak discharges with recurrence intervals in the 10- to 25-year range. On the east side of the central Sierra around Lake Tahoe, peak discharges had recurrence intervals in the 10- to 25-year range. Further south in the Sierra, streams draining into the San Joaquin River Basin had flows with recurrence intervals ranging from 2 to 5 years.

Hydrochemical processes in lowland rivers: insights from in situ, high-resolution monitoring

NASA Astrophysics Data System (ADS)

Wade, A. J.; Palmer-Felgate, E. J.; Halliday, S. J.; Skeffington, R. A.; Loewenthal, M.; Jarvie, H. P.; Bowes, M. J.; Greenway, G. M.; Haswell, S. J.; Bell, I. M.; Joly, E.; Fallatah, A.; Neal, C.; Williams, R. J.; Gozzard, E.; Newman, J. R.

2012-11-01

This paper introduces new insights into the hydrochemical functioning of lowland river systems using field-based spectrophotometric and electrode technologies. The streamwater concentrations of nitrogen species and phosphorus fractions were measured at hourly intervals on a continuous basis at two contrasting sites on tributaries of the River Thames - one draining a rural catchment, the River Enborne, and one draining a more urban system, The Cut. The measurements complement those from an existing network of multi-parameter water quality sondes maintained across the Thames catchment and weekly monitoring based on grab samples. The results of the sub-daily monitoring show that streamwater phosphorus concentrations display highly complex dynamics under storm conditions dependent on the antecedent catchment wetness, and that diurnal phosphorus and nitrogen cycles occur under low flow conditions. The diurnal patterns highlight the dominance of sewage inputs in controlling the streamwater phosphorus and nitrogen concentrations at low flows, even at a distance of 7 km from the nearest sewage treatment works in the rural River Enborne. The time of sample collection is important when judging water quality against ecological thresholds or standards. An exhaustion of the supply of phosphorus from diffuse and multiple septic tank sources during storm events was evident and load estimation was not improved by sub-daily monitoring beyond that achieved by daily sampling because of the eventual reduction in the phosphorus mass entering the stream during events. The results highlight the utility of sub-daily water quality measurements and the discussion considers the practicalities and challenges of in situ, sub-daily monitoring.

Alternative methods to trench backfill.

DOT National Transportation Integrated Search

2005-04-30

Conduit structures dealing with hydraulic drainage needs in the Louisiana highway system include pipe culverts, pipe arch culverts, storm drains, sewers, etc. Although the Louisiana Department of Transportation and Development (LADOTD) has standard s...

24 CFR 200.925b - Residential and institutional building code comparison items.

Code of Federal Regulations, 2010 CFR

2010-04-01

...., materials, allowable stresses, design; (6) Excavation; (e) Materials standards. (f) Construction components...) Plumbing fixtures; (7) Water supply and distribution; (8) Storm drain systems. (j) Electrical. (1) Wiring...

24 CFR 200.925b - Residential and institutional building code comparison items.

Code of Federal Regulations, 2011 CFR

2011-04-01

...., materials, allowable stresses, design; (6) Excavation; (e) Materials standards. (f) Construction components...) Plumbing fixtures; (7) Water supply and distribution; (8) Storm drain systems. (j) Electrical. (1) Wiring...

A Case Study on Nitrogen Uptake and Denitrification in a ...

EPA Pesticide Factsheets

Restoring urban infrastructure and managing the nitrogen cycle represent emerging challenges for urban water quality. We investigated whether stormwater control measures (SCMs), a form of green infrastructure, integrated into restored and degraded urban stream networks can influence watershed nitrogen loads. We hypothesized that hydrologically connected floodplains and SCMs are “hot spots” for nitrogen removal through denitrification because they have ample organic carbon, low dissolved oxygen levels, and extended hydrologic residence times. We tested this hypothesis by comparing nitrogen retention metrics in two urban stream networks (one restored and one urban degraded) that each contain SCMs, and a forested reference watershed at the Baltimore Long-Term Ecological Research site. We used an urban watershed continuum approach which included sampling over both space and time with a combination of: (1) longitudinal reach-scale mass balances of nitrogen and carbon conducted over 2 years during baseflow and storms (n = 24 sampling dates × 15 stream reaches = 360) and (2) 15N push–pull tracer experiments to measure in situ denitrification in SCMs and floodplain features (n = 72). The SCMs consisted of inline wetlands installed below a storm drain outfall at one urban site (restored Spring Branch) and a wetland/wet pond configured in an oxbow design to receive water during high flow events at another highly urbanized site (Gwynns Run). The SCMs significantly d

Urban Runoff and Nutrients Loading Control from Sustainable BMPs (Invited)

NASA Astrophysics Data System (ADS)

Xiao, Q.

2009-12-01

Climate change alters hydrodynamic and nutrient dynamic in both large and small geographic scales. These changes in our freshwater system directly affect drinking water, food production, business, and all aspects of our life. Along with climate change is increasing urbanization which alters natural landscape. Urban runoff has been identified as one of many potential drivers of the decline of pelagic fishes in san Francisco Bay-Delta region. Recent found of Pyrethroids in American River has increased scientists, public, and policy makers’ concern about our fresh water system. Increasing our understanding about the fundamental hydrodynamic, nutrient dynamics, and the transport mechanics of runoff and nutrients are important for future water resource and ecosystem management. Urbanization has resulted in significantly increasing the amount of impervious land cover. Most impervious land covers are hydrophobic that alters surface runoff because of the effects on surface retention storage, rainfall interception, and infiltration. Large volumes of excess storm runoff from urbanized areas cause flooding, water pollution, groundwater recharge deficits, destroyed habitat, beach closures, and toxicity to aquatic organisms. Parking lot alone accounts for more than 11% of these impervious surfaces. Contrast to impervious parking lot, turfgrass can accouter for 12% of urban land in California. Irrigated urban landscapes create considerable benefits to our daily living. However, the use of fertilizers and pesticides has caused environmental problems. Preventing fertilizers and pesticides from entering storm drains is an important goal for both landscape and storm runoff managers. Studies of urban runoff have found that the most fertilizers and pesticides are from dry weather runoff which conveys pollutants to sidewalks, streets, and storm drains. Controlling surface runoff is critical to preventing these pollutants from entering storm drains and water bodies. Large scale construction of runoff retention basins and treatment facilities to meet TMDL (Total Maximum Daily Load) regulations are not cost-effective or practical. An alternative approach is to control runoff and nutrients on-site through installation of decentralized BMPs that detain and infiltrate runoff before it reaches storm drains. Recent developed green-infrastructure which integrating engineered soil and trees to reduce runoff and nutrients loading is a self-sustained best management practice (BMP). This BMP has been testing and used in urban runoff control. In Davis, CA this type of BMPs were installed in a parking lot and a residential property to evaluate the system’s effectiveness on reducing storm runoff and pollutant loading from the parking lot and irrigated landscape. Storm runoff and pollutant loading were measured and monitored during February 2007 thru May 2009 from the parking lot. The BMP reduced surface runoff and nutrients by 88.8% and 95.3%, respectively. In the residential irrigated landscape, the dry-weather runoff was monitored during 2007 irrigation season, the BMP captured almost all dry weather runoff. The performance of these BMPs demonstrated their potential use for reducing runoff and nutrients loading. Control urban runoff from these 23% landscape (i.e., parking lot and irrigated turf grass) could largely alter the runoff and nutrients transport and their dynamic in our water system.

Hydrological Controls on Nutrient Concentrations and Fluxes in Agricultural Catchments

NASA Astrophysics Data System (ADS)

Petry, J.; Soulsby, C.

2002-12-01

This investigation into diffuse agricultural pollution and the hydrological controls that exert a strong influence on both nutrient concentrations and fluxes, was conducted in an intensively farmed lowland catchment in north-east Scotland. The study focuses on spatial and seasonal variations in nutrient concentrations and fluxes at the catchment scale, over a 15-month period. The water quality of the 14.5 km2 Newmills Burn catchment has relatively high nutrient levels with mean concentrations of NO3-N and NH3-N at 6.09 mg/l and 0.28 mg/l respectively. Average PO4-P concentrations are 0.06 mg/l. Over short timescales nutrient concentrations and fluxes are greatest during storm events when PO4-P and NH3-N are mobilised by overland flow in riparian areas, where soils have been compacted by livestock or machinery. Delivery of deeper soil water in subsurface storm flow, facilitated by agricultural under-drainage, produces a marked increase in NO3-N (6.9 mg/l) concentrations on the hydrograph recession limb. A more detailed insight into the catchment response to storm events, and in particular the response of the hydrological pathways which provide the main sources of runoff during storm events, was gained by sampling stream water at 2-hourly intervals during 5 events. End Member Mixing Analysis (EMMA) was carried out using event specific end-member chemistries to differentiate three catchment-scale hydrological pathways (overland flow, subsurface storm flow, groundwater flow) on the basis of observed Si and NO3-N concentrations in sampled source waters. Results show that overland flow generally dominates the storm peak and provides the main flow path by which P is transferred to stream channels during storm events, whilst subsurface storm flows usually dominate the storm hydrograph volumetrically and route NO3-rich soil water to the stream. The study shows that altering hydrological pathways in a catchment can have implications for nutrient management. Whilst buffer strips can reduce the delivery of NH3-N and PO4-P by overland flow to stream channels during storm events, the management of N-rich storm runoff as NO3 via sub-surface drains would require significant interference with the drainage network. This could have a negative impact on agricultural production in the catchment.

Culvert management case studies : Vermont, Oregon, Ohio and Los Angeles county.

DOT National Transportation Integrated Search

2014-04-01

Transportation agencies a re responsible for the operation and maintenance of hydraulic control structures including culverts, drop : systems, and storm drains. It is difficult for transportation agencies to develop accurate and effective performance...

Annual Report: 2010-2011 Storm Season Sampling For NON-DRY DOCK STORMWATER MONITORING FOR PUGET SOUND NAVAL SHIPYARD, BREMERTON, WA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brandenberger, Jill M.; Metallo, David; Johnston, Robert K.

2012-09-01

This interim report summarizes the stormwater monitoring conducted for non-dry dock outfalls in both the confined industrial area and the residential areas of Naval Base Kitsap within the Puget Sound Naval Shipyard (referred to as the Shipyard). This includes the collection, analyses, and descriptive statistics for stormwater sampling conducted from November 2010 through April 2011. Seven stormwater basins within the Shipyard were sampled during at least three storm events to characterize non-dry dock stormwater discharges at selected stormwater drains located within the facility. This serves as the Phase I component of the project and Phase II is planned for themore » 2011-2012 storm season. These data will assist the Navy, USEPA, Ecology and other stakeholders in understanding the nature and condition of stormwater discharges from the Shipyard and inform the permitting process for new outfall discharges. The data from Phase I was compiled with current stormwater data available from the Shipyard, Sinclair/Dyes Inlet watershed, and Puget Sound in order to support technical investigations for the Draft NPDES permit. The permit would require storm event sampling at selected stormwater drains located within the Shipyard. However, the data must be considered on multiple scales to truly understand potential impairments to beneficial uses within Sinclair and Dyes Inlets.« less

Environmental Impact Analysis Process. Environmental Impact Statement for the Closure of Pease Air Force Base. Volume 1

DTIC Science & Technology

1990-05-01

initially known as Portsmouth AFB. In 1957, it was rededicated as Pease AFB in honor of Captain Harl Pease, Jr., a native of Plymouth , Now Hampshire. During... barren soil, up-gradient from storm drains, or in close proximity of floor drains. Corrective action currently being taken is the prompt disposal of...Plant communities on base are indicative of the pine / northern hardwood ecosystem.. The forest resources of. Pease AFB are substantial. More than one

Characterization and statistical modeling of bacterial (Escherichia coli) outflows from watersheds that discharge into Southern Lake Michigan

USGS Publications Warehouse

Olyphant, G.A.; Thomas, Joan; Whitman, R.L.; Harper, D.

2003-01-01

Two watersheds in northwestern Indiana were selected for detailed monitoring of bacterially contaminated discharges (Escherichia coli) into Lake Michigan. A large watershed that drains an urbanized area with treatment plants that release raw sewage during storms discharges into Lake Michigan at the outlet of Burns Ditch. A small watershed drains part of the Great Marsh, a wetland complex that has been disrupted by ditching and limited residential development, at the outlet of Derby Ditch. Monitoring at the outlet of Burns Ditch in 1999 and 2000 indicated that E. coli concentrations vary over two orders of magnitude during storms. During one storm, sewage overflows caused concentrations to increase to more than 10,000 cfu/100 mL for several hours. Monitoring at Derby Ditch from 1997 to 2000 also indicated that E. coli concentrations increase during storms with the highest concentrations generally occurring during rising streamflow. Multiple regression analysis indicated that 60% of the variability in measured outflows of E. coli from Derby Ditch (n = 88) could be accounted for by a model that utilizes continuously measured rainfall, stream discharge, soil temperature and depth to water table in the Great Marsh. A similar analysis indicated that 90% of the variability in measured E. coli concentrations at the outlet of Burns Ditch (n = 43) during storms could be accounted for by a combination of continuously measured water-quality variables including nitrate and ammonium. These models, which utilize data that can be collected on a real-time basis, could form part of an Early Warning System for predicting beach closures.

From existing in situ, high-resolution measurement technologies to lab-on-a-chip - the future of water quality monitoring?

NASA Astrophysics Data System (ADS)

Wade, A. J.; Palmer-Felgate, E. J.; Halliday, S. J.; Skeffington, R. A.; Loewenthal, M.; Jarvie, H. P.; Bowes, M. J.; Greenway, G. M.; Haswell, S. J.; Bell, I. M.; Joly, E.; Fallatah, A.; Neal, C.; Williams, R. J.; Gozzard, E.; Newman, J. R.

2012-05-01

This paper introduces new insights into the hydrochemical functioning of lowland river-systems using field-based spectrophotometric and electrode technologies. The streamwater concentrations of nitrogen species and phosphorus fractions were measured at hourly intervals on a continuous basis at two contrasting sites on tributaries of the River Thames, one draining a rural catchment, the River Enborne, and one draining a more urban system, The Cut. The measurements complement those from an existing network of multi-parameter water quality sondes maintained across the Thames catchment and weekly monitoring based on grab samples. The results of the sub-daily monitoring show that streamwater phosphorus concentrations display highly complex, seemingly chaotic, dynamics under storm conditions dependent on the antecedent catchment wetness, and that diurnal phosphorus and nitrogen cycles occur under low flow conditions. The diurnal patterns highlight the dominance of sewage inputs in controlling the streamwater phosphorus and nitrogen concentrations at low flows, even at a distance of 7 km from the nearest sewage works in the rural, River Enborne, and that the time of sample collection is important when judging water quality against ecological thresholds or standards. An exhaustion of the supply of phosphorus from diffuse and septic tank sources during storm events was evident and load estimation was not improved by sub-daily monitoring beyond that achieved by daily sampling because of the eventual reduction in the phosphorus mass entering the stream during events. The dominance of respiration over photosynthesis in The Cut indicated a prevalence of heterotrophic algae, and the seasonal patterns in respiration and photosynthesis corresponded with those of temperature and light in this nutrient over-enriched stream. These results highlight the utility of sub-daily water quality measurements but the deployment of modified wet-chemistry technologies into the field was limited by mains electricity availability. A new approach is therefore needed to allow measurement of a wide range of analytes at a broader range of locations for the development of water quality web-sensor networks. The development and field deployment of a miniaturised "lab-on-a-chip" ion chromatograph is proposed and justified.

Children's Health Curriculum Lesson 6: Keeping All of Our Waterways Clean

EPA Pesticide Factsheets

This lesson helps kids understand the importance of water in our lives and describes the life cycle of freshwater. It also discusses how to keep trash from getting in storm drains and polluting our waterways.

NPDES Permit for Denver Federal Center Building 52A in Colorado

EPA Pesticide Factsheets

Under NPDES permit CO-0034860, the GSA is authorized to discharge wastewater from construction dewatering activities at Denver Federal Center Building 52A in Lakewood, Colo., to to the storm drain system entering McIntyre Gulch.

VARIATION OF PATHOGEN DENSITIES IN URBAN STORMWATER RUNOFF WITH LAND USE

EPA Science Inventory

Stormwater runoff samples were collected from outfalls draining small municipal separate storm sewer systems. The samples were collected from three land use areas (high-density residential, low-density residential, and landscaped commercial). The concentrations of organisms in ...

VARIATION OF PATHOGEN DENSITITES IN URBAN STORMWATER RUNOFF WITH LAND USE

EPA Science Inventory

Stormwater runoff samples were collected from outfalls draining small municipal separate storm sewer systems. The samples were collected from three land use areas (high-density residential, low-density residential, and landscaped commercial). The concentrations of organisms in ...

Runoff thresholds and land-to-marine ecosystem connectivity in a dry tropical setting: St. John, US Virgin Islands

NASA Astrophysics Data System (ADS)

Ramos-Scharron, C. E.; LaFevor, M. C.; Roy, J.

2017-12-01

Developing a conceptually sound yet practical understanding of runoff and sediment delivery from human occupied lands to tropical ocean waters still represents a pivotal need of coral reef management worldwide. In the dry tropical and ephemeral streamflow setting that typifies the small watersheds ( 1s km2) draining the US Virgin Islands, changes in hydrologic and sediment delivery dynamics provoked by unsurfaced road networks represent a major threat to coral reefs and other sensitive marine ecosystems. Through a combined empirical and modeling approach, this study evaluates how road building and associated stormflow restoration strategies affect rainfall thresholds for runoff generation at varying spatial scales and their impact on land-to-sea connectivity. Rainfall thresholds and runoff coefficients for precipitation excess on unpaved roads are 2-3 mm and 22-30% (respectively) or a full order of magnitude different from those for undisturbed hillslopes and watersheds. Here we discuss the use of a `volume-to-breakthrough' inspired index to predict the potential of road runoff to reach downslope portions of the watershed and the coastline as runon. The index integrates the effects of storm-by-storm runoff accumulation for every road drainage point with its flow distance to specific locations along the stream network. While large runoff volumes and short flow distances imply a relatively high connectivity potential, small volumes and long distances are associated to low delivery potential. The index has proven able to discern observed runoff responses under a variety of road-stream network scenarios and rainfall conditions. These results enhance our understanding of ephemeral stream hydrology and are serving to improve coral reef management strategies throughout the Northeastern Caribbean.

Extraordinary flood response of a small urban watershed to short-duration convective rainfall

USGS Publications Warehouse

Smith, J.A.; Miller, A.J.; Baeck, M.L.; Nelson, P.A.; Fisher, G.T.; Meierdiercks, K.L.

2005-01-01

The 9.1 km2 Moores Run watershed in Baltimore, Maryland, experiences floods with unit discharge peaks exceeding 1 m3 s-1 km-2 12 times yr-1, on average. Few, if any, drainage basins in the continental United States have a higher frequency. A thunderstorm system on 13 June 2003 produced the record flood peak (13.2 m3 s-1 km-2) during the 6-yr stream gauging record of Moores Run. In this paper, the hydrometeorology, hydrology, and hydraulics of extreme floods in Moores Run are examined through analyses of the 13 June 2003 storm and flood, as well as other major storm and flood events during the 2000-03 time period. The 13 June 2003 flood, like most floods in Moores Run, was produced by an organized system of thunderstorms. Analyses of the 13 June 2003 storm, which are based on volume scan reflectivity observations from the Sterling, Virginia, WSR-88D radar, are used to characterize the spatial and temporal variability of flash flood producing rainfall. Hydrology of flood response in Moores Run is characterized by highly efficient concentration of runoff through the storm drain network and relatively low runoff ratios. A detailed survey of high-water marks for the 13 June 2003 flood is used, in combination with analyses based on a 2D, depth-averaged open channel flow model (TELEMAC 2D) to examine hydraulics of the 13 June 2003 flood. Hydraulic analyses are used to examine peak discharge estimates for the 13 June flood peak, propagation of flood waves in the Moores Run channel, and 2D flow features associated with channel and floodplain geometry. ?? 2005 American Meteorological Society.

Comparison of permeable pavement types : hydrology, design, installation, maintenance and cost.

DOT National Transportation Integrated Search

2012-01-13

"WisDOTs regional storm water engineer for the Southeast Region is interested in developing a park-and-ride with : porous pavement, possibly with the PaveDrain brand of permeable block. Research was needed to determine how : well permeable pavemen...

VARIATIONS OF MICROORGANISM CONCENTRATIONS IN URBAN STORMWATER RUNOFF WITH LAND USE AND SEASONS

EPA Science Inventory

Stormwater runoff samples were collected from outfalls draining small municipal separate storm sewer systems. The samples were collected from three different land use areas based on local designation (high-density residential, low-density residential, and landscaped commercial)....

System of GIS-Based Hydrologic and Hydraulic Applications for Highway Engineering: Summary Report

DOT National Transportation Integrated Search

1999-10-01

A significant part of the cost of most highway projects is attributable to drainage facilities, such as bridges, highway culverts, storm drains, and water quality and quantity control structures. Design of these facilities involves a hydrologic analy...

Storm water runoff measurements of copper from a naturally patinated roof and from a parking space. Aspects on environmental fate and chemical speciation.

PubMed

Odnevall Wallinder, I; Hedberg, Y; Dromberg, P

2009-12-01

Release of copper from a naturally aged copper roof on a shopping centre building in a suburban site of Stockholm has been measured during different rain events after its interaction with the internal drainage system and storm drains made of cast iron and concrete. Concentrations of copper removed by means of urban storm water from a nearby parking space have been determined for comparison. Predictions and measurements of the chemical speciation of released copper are discussed compared to the total concentration, and to threshold values for freshwater and drinking water. The results clearly illustrate that the major part of the released copper from the roof is readily retained already during transport through the internal drainage system of the building, a pathway that also changes the chemical speciation of released copper and its bioavailable fraction. Most copper, not retained by cast iron and concrete surfaces, was strongly complexed to organic matter. The median concentration of free cupric ions and weak copper complexes was less than, or within the range of reported no effect concentrations, NOECs, of copper in surface waters. The parking space contributed with significantly higher and time-dependent concentrations of total copper compared to measured concentrations of copper from the roof after the interaction with the drainage system. Most copper in the surface runoff water was strongly complexed with organic matter, hence reducing the bioavailable fraction significantly to concentrations within the NOEC range. Dilution with other sources of urban storm water will reduce the released concentration of copper even further. The results illustrate that already the internal drainage system and the storm drains made of cast iron and concrete act as efficient sinks for released copper which means that any installation of additional infiltration devices is redundant.

Results of the flowmeter-injection test in the Long Valley Exploratory Well (Phase II), Long Valley, California

USGS Publications Warehouse

Morin, R.H.; Sorey, M.L.; Jacobson, R.D.

1993-01-01

Bayboro Harbor and the Port of St. Petersburg, Florida, form a manmade basin adjacent to Tampa Bay that may supply turbid water to the bay and subsequently affect light penetration in water in the bay. To address concerns about the nature and extent of this potential problem, resuspension of bottom sediments, sedimentation, and tributary storm discharge in the basin were studied. Study results indicated that tidal currents, wind waves, and seiche motions do not resuspend bottom sediments. The maneuvering of a cruise ship in the port resuspended bottom sediments, but these sediments settled within 2 hours. Tidal currents and wave action were not large enough o prevent the resuspended sediments from settling in the basin. Analysis of bathymetric surveys of the port made in 1981, 1986, 1987, and 1989 indicates that the cruise ship has deepened the port along its route and that the displaced sediment has been deposited elsewhere within the port. The storm discharge from two tributaries and the effect of tributary storm runoff on the water quality of the harbor were studied during a storm on November 9, 1989. Booker Creek, which drains an urban watershed, was stratified with a thin layer of turbid freshwater flowing into the harbor over a layer of less turbid saltwater. Salt Creek, which primarily drains Lake Maggiore, was only partially stratified and was less turbid. The turbid water from the creeks increased the turbidity only slightly in the harbor, probably because of mixing with less turbid water and particle settling. Thus, the basin provides mixing and settling, which diminish and eliminate the potentially adverse effect on Tampa Bay from tributary storm runoff and large vessel traffic in the basin.

Use of stimulable bioluminescence from dinoflagellates as a means of detecting toxicity in the marine environment. (Reannouncement with new availability information). Professional paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lapota, D.; Moskowitz, G.; Grovhoug, J.

1993-03-01

Phytoplankton bioassays have been used as biological tools in assessing environmental contamination. In our laboratory, a simple bioassay has been developed which measures the light output from bioluminescence dinoflagellates for assessment of toxic effects when exposed to a single toxicant or mixture. Successful use of this type of bioassay has provided data on the acute response and has demonstrated the chronic effects, from hours up to 11 days, on dinoflagellate cells of Pyrocystis lunula and Gonyaulax polyedra upon exposure to several metals and storm drain effluent. Dinoflagellate cells were exposed to various concentrations of tributyltin chloride (TBTCI), copper (11) sulfatemore » (CUS04), zinc sulfate (ZnSO4), or storm drain effluent. Stimulable bioluminescence was measured at each test period (3 or 4 h, 24 h, 48 h, 72 h, etc.) following setup for all assays. Cells were kept in the dark for 3 or 4 h prior to testing. Stirring the cells within the chamber stimulated maximum bioluminescence from the dinoflagellates. An IC50 (an estimated concentration that is likely to cause a 50% reduction in light output) was estimated for all assays. The trend of light reduction as a response to increasing dose level of test article was observed in all assays. A reduction in light output was measured from cells exposed to 1.6, 4.2, and 12.8 ug/L TBTCI. The IC50 decreased from 8.5 ug/L at 120 h to 3.0 ug/L at 264 h. The cells exposed to 6.25%, 12.5%, and 25.0% storm drain effluent exhibited a statistically significant (P=0.05) reduction in light output in as little as 3 h exposure....Plankton, Oceanography, Bioluminescence.« less

Water table dynamics in undisturbed, drained and restored blanket peat

NASA Astrophysics Data System (ADS)

Holden, J.; Wallage, Z. E.; Lane, S. N.; McDonald, A. T.

2011-05-01

SummaryPeatland water table depth is an important control on runoff production, plant growth and carbon cycling. Many peatlands have been drained but are now subject to activities that might lead to their restoration including the damming of artificial drains. This paper investigates water table dynamics on intact, drained and restored peatland slopes in a blanket peat in northern England using transects of automated water table recorders. Long-term (18 month), seasonal and short-term (storm event) records are explored. The restored site had drains blocked 6 years prior to monitoring commencing. The spatially-weighted mean water table depths over an 18 month period were -5.8 cm, -8.9 cm and -11.5 cm at the intact, restored and drained sites respectively. Most components of water table behaviour at the restored site, including depth exceedance probability curves, seasonality of water table variability, and water table responses to individual rainfall events were intermediate between that of the drained and intact sites. Responses also depended on location with respect to the drains. The results show that restoration of drained blanket peat is difficult and the water table dynamics may not function in the same way as those in undisturbed blanket peat even many years after management intervention. Further measurement of hydrological processes and water table responses to peatland restoration are required to inform land managers of the hydrological success of those projects.

Quantitative and qualitative hydrologic balance for a suburban watershed with a separate sewer system (Nantes, France).

PubMed

Ruban, V; Larrarte, F; Berthier, M; Favreau, L; Sauvourel, Y; Letellier, L; Mosisni, M L; Raimbault, G

2005-01-01

A qualitative and quantitative budget at the outlet of the storm-water runoff system of a small suburban watershed is presented together with some data regarding waste-water. 445,000 m3 (34% of the rain-water volume) were drained by the storm-water runoff system and 40,879 m3 by the waste-water system from September 2002 to March 2004. Storm-water runoff is generally not heavily polluted with regard to trace metals but concentrations occasionally exceed the standards for surface water of good quality. On the contrary, pesticides (diuron and glyphosate) have very high concentrations especially in spring and autumn when their use is maximum. As the St Joseph storm-water runoff is finally discharged into the Erdre River, measures to reduce the use of these pollutants should be considered.

Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

USDA-ARS?s Scientific Manuscript database

Controls on baseflow nutrient concentrations in agroecosystems are poorly characterized in comparison with storm events. However, in landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can drive deleterious environm...

City of El Monte Stormwater System Improvement Project FONSI and EA

EPA Pesticide Factsheets

The U.S. Environmental Protection Agency (EPA) Region 9 intends to award a grant to the City of El Monte, California, in accordance with the in accordance with the Consolidated Appropriations Act of FY2009 for the Garvey Storm Drain Reconstruction Project.

Stormwater Volume Control to Prevent Increases in Lake Flooding and Dam Failure Risk

NASA Astrophysics Data System (ADS)

Potter, K. W.

2017-12-01

Urban expansion is not often considered a major factor contributing to dam failure. But if urbanization occurs without mitigation of the hydrologic impacts, the risk of dam failure will increase. Of particular concern are increases in the volume of storm runoff resulting from increases in the extent of impervious surfaces. Storm runoff volumes are not regulated for much the U.S, and where they are, the required control is commonly less than 100%. Unmitigated increases in runoff volume due to urbanization can pose a risk to dams. A recent technical advisory committee of Dane County has recommended that the county require 100% control of stormwater volumes for new developments. The primary motivation was to prevent increases in the water levels in the Yahara Lakes, slowly draining lakes that are highly sensitive to runoff volume. The recommendations included the use of "volume trading" to achieve efficient compliance. Such recommendations should be considered for other slowly draining lakes, including those created by artificial structures.

Environmental Assessment: North Ditch Crossing Culvert Replacement at West of Grand Forks AFB, North Dakota

DTIC Science & Technology

2003-08-09

this area. Wood nettle (Laportea canadensis), stinging nettle (Urtica dioica), beggars’ ticks (Bidens frondosa), and waterleaf (Hydrophyllum viginianum...materials, herbicides, and insecticides from entering public waters (this includes eliminating sediment from entering the storm drain inlets). Water used

Hydrology and Water and Sediment Quality at James Campbell National Wildlife Refuge near Kahuku, Island of Oahu, Hawaii

USGS Publications Warehouse

Hunt, Charles D.; De Carlo, Eric H.

2000-01-01

The James Campbell National Wildlife Refuge occupies two lowland marsh and pond complexes on the northern coastal plain of Oahu: the mostly natural ponds and wetlands of the Punamano Unit and the constructed ponds of the Kii Unit. The U.S. Fish and Wildlife Service manages the Refuge primarily to protect and enhance habitat for four endangered species of Hawaiian waterbirds. Kii Unit is fed by artesian wells and rainfall, whereas Punamano Unit is fed naturally by rainfall, runoff, and ground-water seepage. Streams drain from the uplands into lowland ditches that pass through Kii Unit on their way to the ocean. A high-capacity pump transfers water from the inner ditch terminus at Kii to the ocean outlet channel. Stormwaters also exit the inner ditch system over flood-relief swales near the outlet pump and through a culvert with a one-way valve. A hydrologic investigation was done from November 1996 through February 1998 to identify and quantify principal inflows and outflows of water to and from the Refuge, identify hydraulic factors affecting flooding, document ground-water/surface-water interactions, determine the adequacy of the current freshwater supply, and determine water and sediment quality. These goals were accomplished by installing and operating a network of stream-gaging stations, meteorology stations, and shallow ground-water piezometers, by computing water budgets for the two Refuge units, and by sampling and analyzing water and pond-bottom sediments for major ions, trace metals, and organic compounds. Streamflow during the study was dominated by winter stormflows, followed by a gradual recession of flow into summer 1997, as water that had been stored in alluvial fans drained to lowland ditches. Outflow at the ditch terminus in 1997 was 125 million gallons greater than measured inflow to the coastal plain, mainly reflecting gains from ground water along the ditches between outlying gages and the ditch terminus. Of the measured 1997 outflow, 98 percent was through the Kii outlet pump, with the outlet culvert valve only opening for brief periods during storms. Large volumes of stormflow overflowed the flood-relief swales unmeasured. The largest storm of the study, in November 1996, was estimated to have a flood frequency of about 3 to 4 years. Streamflow exceeded culvert capacity and overtopped Kamehameha Highway at Kalaeokahipa Stream and Hospital ditch. Slight overbank flooding in Kii ditch resulted strictly from high discharge. Minor overbank flooding farther out on the coastal plain probably was caused mainly by the small hydraulic gradients available to convey stormflows along the lowland ditches. Stormwaters flooded Kii ponds and flowed back upstream along Punamano ditch into Punamano marsh, introducing suspended sediment and possibly other contaminants to the Refuge. Two smaller storms in January 1997 resulted in smaller flows and no overbank flooding. The Kii outlet pump ran continuously for 7 days during the November 1996 storm and for 1 to 2 days during the January 1997 storms. During all three storms, the outlet culvert valve opened and the inner ditches overtopped the flood-relief swales, allowing free outflow of water from the inner ditch. Backwater effects hindered drainage during the January 1997 storms at Hospital ditch at Kamehameha Highway, and at Punamano ditch at Nudist Camp Road (where the backflow into Punamano marsh in November 1996 constituted an extreme backwater effect). A probable marine backwater effect was imposed at the ocean outlet ditch during the November 1996 storm through a combination of high spring tides and wave setup from large surf. Whether this backwater effect propagated upstream in the ditches to affect inland sites could not be determined conclusively. A sand plug may have built up in the ocean outlet channel before the November 1996 storm, but if so, it probably washed out prior to, or early in the storm, and was not present at the time of peak stage at inlan

Travel time analysis for a subsurface drained sub-watershed in Upper Big Walnut Creek Watershed, Ohio

USDA-ARS?s Scientific Manuscript database

Runoff travel time, which is a function of watershed and storm characteristics, is an important parameter affecting the prediction accuracy of hydrologic models. Although, time of concentration (tc) is a most widely used time parameter, it has multiple conceptual and computational definitions. Most ...

Understanding Sediment Processes of Los Laureles Canyon in the Binational Tijuana River watershed

EPA Science Inventory

Tijuana River Basin originates in Mexico and drains 4465 km2 into the Tijuana River Estuary National Research Reserve, a protected coastal wetland in California that supports 400 species of birds. During storms, excessive erosion in Tijuana produces sediment loads that bury nativ...

An Inevitable Moment: US Brain Drain

ERIC Educational Resources Information Center

Coppola, Brian P.

2015-01-01

In this article, Brian Coppola begins by discussing the 2007 National Academies of Sciences (NAS) publication, "Rising Above the Gathering Storm" which called for for reprioritizing investments because "the world is changing rapidly, and our advantages are no longer unique. Without a renewed effort to bolster the foundations of our…

Magnitude-Based Postfire Debris Flow Rainfall Accumulation-Duration Thresholds for Emergency-Response Planning

NASA Astrophysics Data System (ADS)

Cannon, S. H.; Boldt, E. M.; Laber, J. L.; Kean, J. W.; Staley, D. M.

2011-12-01

Following wildfires, emergency-response and public-safety agencies can be faced with evacuation and resource-deployment decisions well in advance of coming winter storms and during storms themselves. Information critical to these decisions is needed for recently burned areas in the San Gabriel Mountains of southern California. A compilation of information on the hydrologic response to winter storms from recently burned areas in southern California steeplands is used to develop a system for classifying magnitudes of hydrologic response in this setting. The four-class system describes combinations of reported volumes of individual debris flows, consequences of debris flows and floods in an urban setting, and spatial extents of the hydrologic response. Magnitude 0 events show a negligible response, while Magnitude I events are characterized by small (<1,000 m3) debris flows or low-discharge floods produced from one or two drainage basins. A few culverts and storm drains may be blocked, a few streets may be partially flooded or blocked by water and debris, and a few buildings near the mountain front may be damaged. Magnitude II events are characterized by two to five moderately-sized (1,000 to 10,000 m3) debris flows or one large (>10,000 m3) event. Several culverts or storm drains may be blocked or fail, several streets may be flooded or completely blocked by water and debris, and buildings, streets, and bridges may be damaged or destroyed. Magnitude III events consist of widespread and abundant debris flows of volumes >10,000 m3 and high discharge flooding causing significant impact to the built environment. Many streets, storm drains, and streets may be completely blocked by debris, making many streets unsafe for travel. Several large buildings, sections of infrastructure corridors and bridges may be damaged or destroyed. The range of rainfall conditions associated with different magnitude classes are defined by correlating local rainfall data with the response magnitude information. Magnitude 0 events can be expected when within-storm rainfall accumulations (A) of given durations (D) fall below the threshold A=0.4D0.5. Magnitude I events can be expected when storm rainfall conditions are above the threshold A=0.4D0.5 and below A=0.5D0.6 for durations greater than 1 hour. Magnitude II events will be generated in response to rainfall accumulations and durations between A=0.4D0.5 and A=0.9D0.5 for durations less than one hour, and between A=0.5D0.6 and A=0.9D0.5 for durations greater than one hour. Magnitude III events can be expected in response to rainfall conditions above the threshold A=0.9D 0.5. Rainfall threshold-magnitude relations are linked with potential emergency-response actions as an emergency-response decision chart, which leads a user through steps to determine potential event magnitudes and identify possible evacuation and resource-deployment levels. Use of this information in the planning and response decision-making process could result in increased safety for both the public and emergency responders.

Combined effect of storm movement and drainage network configuration on flood peaks

NASA Astrophysics Data System (ADS)

Seo, Yongwon; Son, Kwang Ik; Choi, Hyun Il

2016-04-01

This presentation reports the combined effect of storm movement and drainage network layout on resulting hydrographs and its implication to flood process and also flood mitigation. First, we investigate, in general terms, the effects of storm movement on the resulting flood peaks, and the underlying process controls. For this purpose, we utilize a broad theoretical framework that uses characteristic time and space scales associated with stationary rainstorms as well as moving rainstorms. For a stationary rainstorm the characteristic timescales that govern the peak response include two intrinsic timescales of a catchment and one extrinsic timescale of a rainstorm. On the other hand, for a moving rainstorm, two additional extrinsic scales are required; the storm travel time and storm size. We show that the relationship between the peak response and the timescales appropriate for a stationary rainstorm can be extended in a straightforward manner to describe the peak response for a moving rainstorm. For moving rainstorms, we show that the augmentation of peak response arises from both effect of overlaying the responses from subcatchments (resonance condition) and effect of increased responses from subcatchments due to increased duration (interdependence), which results in maximum peak response when the moving rainstorm is slower than the channel flow velocity. Second, we show the relation between channel network configurations and hydrograph sensitivity to storm kinematics. For this purpose, Gibbs' model is used to evaluate the network characteristics. The results show that the storm kinematics that produces the maximum peak discharge depends on the network configuration because the resonance condition changes with the network configuration. We show that an "efficient" network layout is more sensitive and results in higher increase in peak response compared to "inefficient" one. These results imply different flood potential risks for river networks depending on network characteristics. In addition, they imply a possibility of an alternative drainage network layout as an effective measure for flood mitigation in urban environments.

76 FR 66629 - Establishment of the Pine Mountain-Cloverdale Peak Viticultural Area

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

... explains. The petition states that local growers report that Pine Mountain vineyards are naturally free of.... Southern storms often stall over Pine Mountain and the Mayacmas range, dropping more rain than in other..., and very well to excessively well-drained. Also, these mountain soils include large amounts of sand...

The burial of headwater streams in drainage pipes reduces in-stream nitrate retention: results from two US metropolitan areas

EPA Science Inventory

Urbanization causes stream degradation in various ways, but perhaps the most extreme example is the burial of streams in underground storm drains to facilitate above ground development or to promote the rapid conveyance of stormwater. Stream burial is extensive in urban basins (...

Evaluating the SWAT model for a low-gradient forested watershed in coastal South Carolina

Treesearch

D.M. Amatya; M.K. Jha.

2011-01-01

Modeling the hydrology of low�]gradient forested watersheds on shallow, poorly drained soils of the coastal plain is a challenging task due to complexities in watershed delineation, microtopography, evapotranspiration, runoff generation processes and pathways including flooding and submergence caused by tropical storms, and complexity of vegetation species....

76 FR 18066 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-01

...-site) 518 tons of contaminated soil. During the removal, water samples taken from the storm drain... demolition phase took place immediately prior to and in connection with the relocation of soil and sediment... informing the public that the deletion will not take effect. ADDRESSES: Submit your comments, identified by...

The role of storm scale, position and movement in controlling urban flood response

NASA Astrophysics Data System (ADS)

ten Veldhuis, Marie-claire; Zhou, Zhengzheng; Yang, Long; Liu, Shuguang; Smith, James

2018-01-01

The impact of spatial and temporal variability of rainfall on hydrological response remains poorly understood, in particular in urban catchments due to their strong variability in land use, a high degree of imperviousness and the presence of stormwater infrastructure. In this study, we analyze the effect of storm scale, position and movement in relation to basin scale and flow-path network structure on urban hydrological response. A catalog of 279 peak events was extracted from a high-quality observational dataset covering 15 years of flow observations and radar rainfall data for five (semi)urbanized basins ranging from 7.0 to 111.1 km2 in size. Results showed that the largest peak flows in the event catalog were associated with storm core scales exceeding basin scale, for all except the largest basin. Spatial scale of flood-producing storm events in the smaller basins fell into two groups: storms of large spatial scales exceeding basin size or small, concentrated events, with storm core much smaller than basin size. For the majority of events, spatial rainfall variability was strongly smoothed by the flow-path network, increasingly so for larger basin size. Correlation analysis showed that position of the storm in relation to the flow-path network was significantly correlated with peak flow in the smallest and in the two more urbanized basins. Analysis of storm movement relative to the flow-path network showed that direction of storm movement, upstream or downstream relative to the flow-path network, had little influence on hydrological response. Slow-moving storms tend to be associated with higher peak flows and longer lag times. Unexpectedly, position of the storm relative to impervious cover within the basins had little effect on flow peaks. These findings show the importance of observation-based analysis in validating and improving our understanding of interactions between the spatial distribution of rainfall and catchment variability.

Stormwater Pollution Prevention Plan (SWPPP) for Coal Storage Area Stabilization Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Project and Design Engineering

2011-03-01

The scope of this project is to stabilize the abandoned coal storage area and redirect the storm water runoff from sanitary sewer system to the storm drain system. Currently, the existing storm water runoff is directed to a perimeter concrete drainage swale and collected in a containment basin. The collected water is then pumped to a treatment facility and after treatment, is discharged to the Y-12 sanitary sewer system. The existing drainage swale and collection basin along with silt fencing will be used during aggregate placement and grading to provide erosion and sediment control. Inlet protection will also be installedmore » around existing structures during the storm water diversion construction. This project scope will include the installation of a non-woven geotextile fabric and compacted mineral aggregate base (paving optional) to stabilize the site. The geotextile specifications are provided on the vendor cut sheets in Appendix B. The installation of a storm water collection/retention area will also be installed on the southern side of the site in accordance with EPA Technical Guidance on Implementing the Stormwater Runoff Requirements for federal Projects under Section 438 of the Energy Independence and Security Act. The total area to be disturbed is approximately 2.5 acres. The order of activities for this Stormwater Pollution Prevention Plan (SWPPP) will be: (1) post notice of coverage (NOC) in a prominent display near entrance of the site; (2) install rain gauge on site or contact Y-12 Plant Shift Superintendent daily for Met tower rain gauge readings; (3) install stabilized construction exit on site; (4) install silt fencing along perimeter as indicated on the attached site plan; (5) regrade site; (6) install geotextile fabric and compacted mineral aggregate base; (7) install catch basin inlet protection where required; (8) excavate and lower existing catch basin tops, re-grade and asphalt to drain; and (9) when all disturbed areas are re-stabilized, remove silt fencing and any other temporary erosion control.« less

Evaluating the critical source area concept of phosphorus loss from soils to water-bodies in agricultural catchments.

PubMed

Shore, M; Jordan, P; Mellander, P-E; Kelly-Quinn, M; Wall, D P; Murphy, P N C; Melland, A R

2014-08-15

Using data collected from six basins located across two hydrologically contrasting agricultural catchments, this study investigated whether transport metrics alone provide better estimates of storm phosphorus (P) loss from basins than critical source area (CSA) metrics which combine source factors as well. Concentrations and loads of P in quickflow (QF) were measured at basin outlets during four storm events and were compared with dynamic (QF magnitude) and static (extent of highly-connected, poorly-drained soils) transport metrics and a CSA metric (extent of highly-connected, poorly-drained soils with excess plant-available P). Pairwise comparisons between basins with similar CSA risks but contrasting QF magnitudes showed that QF flow-weighted mean TRP (total molybdate-reactive P) concentrations and loads were frequently (at least 11 of 14 comparisons) more than 40% higher in basins with the highest QF magnitudes. Furthermore, static transport metrics reliably discerned relative QF magnitudes between these basins. However, particulate P (PP) concentrations were often (6 of 14 comparisons) higher in basins with the lowest QF magnitudes, most likely due to soil-management activities (e.g. ploughing), in these predominantly arable basins at these times. Pairwise comparisons between basins with contrasting CSA risks and similar QF magnitudes showed that TRP and PP concentrations and loads did not reflect trends in CSA risk or QF magnitude. Static transport metrics did not discern relative QF magnitudes between these basins. In basins with contrasting transport risks, storm TRP concentrations and loads were well differentiated by dynamic or static transport metrics alone, regardless of differences in soil P. In basins with similar transport risks, dynamic transport metrics and P source information additional to soil P may be required to predict relative storm TRP concentrations and loads. Regardless of differences in transport risk, information on land use and management, may be required to predict relative differences in storm PP concentrations between these agricultural basins. Copyright © 2014 Elsevier B.V. All rights reserved.

Streams in the urban heat island: spatial and temporal variability in temperature

USGS Publications Warehouse

Somers, Kayleigh A.; Bernhardt, Emily S.; Grace, James B.; Hassett, Brooke A.; Sudduth, Elizabeth B.; Wang, Siyi; Urban, Dean L.

2013-01-01

Streams draining urban heat islands tend to be hotter than rural and forested streams at baseflow because of warmer urban air and ground temperatures, paved surfaces, and decreased riparian canopy. Urban infrastructure efficiently routes runoff over hot impervious surfaces and through storm drains directly into streams and can lead to rapid, dramatic increases in temperature. Thermal regimes affect habitat quality and biogeochemical processes, and changes can be lethal if temperatures exceed upper tolerance limits of aquatic fauna. In summer 2009, we collected continuous (10-min interval) temperature data in 60 streams spanning a range of development intensity in the Piedmont of North Carolina, USA. The 5 most urbanized streams averaged 21.1°C at baseflow, compared to 19.5°C in the 5 most forested streams. Temperatures in urban streams rose as much as 4°C during a small regional storm, whereas the same storm led to extremely small to no changes in temperature in forested streams. Over a kilometer of stream length, baseflow temperature varied by as much as 10°C in an urban stream and as little as 2°C in a forested stream. We used structural equation modeling to explore how reach- and catchment-scale attributes interact to explain maximum temperatures and magnitudes of storm-flow temperature surges. The best predictive model of baseflow temperatures (R2  =  0.461) included moderately strong pathways directly (extent of development and road density) and indirectly, as mediated by reach-scale factors (canopy closure and stream width), from catchment-scale factors. The strongest influence on storm-flow temperature surges appeared to be % development in the catchment. Reach-scale factors, such as the extent of riparian forest and stream width, had little mitigating influence (R2  =  0.448). Stream temperature is an essential, but overlooked, aspect of the urban stream syndrome and is affected by reach-scale habitat variables, catchment-scale urbanization, and stream thermal regimes.

Ground-water recharge from streamflow data, NW Florida

USGS Publications Warehouse

Vecchioli, John; Bridges, W.C.; Rumenik, Roger P.; Grubbs, J.W.

1991-01-01

Annual base flows of streams draining Okaloosa County and adjacent areas in northwest Florida were determined through hydrograph separation and correlation techniques for purposes of evaluating variations in ground-water recharge rates. Base flows were least in the northern part of the county and greatest in the southern part. Topographic and soils data were then superimposed on the distribution of base flow by subbasin to produce a map showing distribution of ground-water recharge throughout the county. The highest recharge rate occurs in the southern part of the county where relatively flat upland areas underlain by excessively drained sandy soils result in minimal storm runoff and evapotranspiration.

Evaluation of Deep Learning Representations of Spatial Storm Data

NASA Astrophysics Data System (ADS)

Gagne, D. J., II; Haupt, S. E.; Nychka, D. W.

2017-12-01

The spatial structure of a severe thunderstorm and its surrounding environment provide useful information about the potential for severe weather hazards, including tornadoes, hail, and high winds. Statistics computed over the area of a storm or from the pre-storm environment can provide descriptive information but fail to capture structural information. Because the storm environment is a complex, high-dimensional space, identifying methods to encode important spatial storm information in a low-dimensional form should aid analysis and prediction of storms by statistical and machine learning models. Principal component analysis (PCA), a more traditional approach, transforms high-dimensional data into a set of linearly uncorrelated, orthogonal components ordered by the amount of variance explained by each component. The burgeoning field of deep learning offers two potential approaches to this problem. Convolutional Neural Networks are a supervised learning method for transforming spatial data into a hierarchical set of feature maps that correspond with relevant combinations of spatial structures in the data. Generative Adversarial Networks (GANs) are an unsupervised deep learning model that uses two neural networks trained against each other to produce encoded representations of spatial data. These different spatial encoding methods were evaluated on the prediction of severe hail for a large set of storm patches extracted from the NCAR convection-allowing ensemble. Each storm patch contains information about storm structure and the near-storm environment. Logistic regression and random forest models were trained using the PCA and GAN encodings of the storm data and were compared against the predictions from a convolutional neural network. All methods showed skill over climatology at predicting the probability of severe hail. However, the verification scores among the methods were very similar and the predictions were highly correlated. Further evaluations are being performed to determine how the choice of input variables affects the results.

(abstract) Application of the GPS Worldwide Network in the Study of Global Ionospheric Storms

NASA Technical Reports Server (NTRS)

Ho, C. M.; Mannucci, A. J.; Lindqwister, U. J.; Pi, X.; Sparks, L. C.; Rao, A. M.; Wilsion, B. D.; Yuan, D. N.; Reyes, M.

1997-01-01

Ionospheric storm dynamics as a response to the geomagnetic storms is a very complicated global process involving many different mechanisms. Studying ionospheric storms will help us to understand the energy coupling process between the Sun and Earth and possibly also to effectively forecast space weather changes. Such a study requires a worldwide monitoring system. The worldwide GPS network, for the first time, makes near real-time global ionospheric TEC measurements a possibility.

The Surge, Wave, and Tide Hydrodynamics (SWaTH) network of the U.S. Geological Survey—Past and future implementation of storm-response monitoring, data collection, and data delivery

USGS Publications Warehouse

Verdi, Richard J.; Lotspeich, R. Russell; Robbins, Jeanne C.; Busciolano, Ronald J.; Mullaney, John R.; Massey, Andrew J.; Banks, William S.; Roland, Mark A.; Jenter, Harry L.; Peppler, Marie C.; Suro, Thomas P.; Schubert, Christopher E.; Nardi, Mark R.

2017-06-20

After Hurricane Sandy made landfall along the northeastern Atlantic coast of the United States on October 29, 2012, the U.S. Geological Survey (USGS) carried out scientific investigations to assist with protecting coastal communities and resources from future flooding. The work included development and implementation of the Surge, Wave, and Tide Hydrodynamics (SWaTH) network consisting of more than 900 monitoring stations. The SWaTH network was designed to greatly improve the collection and timely dissemination of information related to storm surge and coastal flooding. The network provides a significant enhancement to USGS data-collection capabilities in the region impacted by Hurricane Sandy and represents a new strategy for observing and monitoring coastal storms, which should result in improved understanding, prediction, and warning of storm-surge impacts and lead to more resilient coastal communities.As innovative as it is, SWaTH evolved from previous USGS efforts to collect storm-surge data needed by others to improve storm-surge modeling, warning, and mitigation. This report discusses the development and implementation of the SWaTH network, and some of the regional stories associated with the landfall of Hurricane Sandy, as well as some previous events that informed the SWaTH development effort. Additional discussions on the mechanics of inundation and how the USGS is working with partners to help protect coastal communities from future storm impacts are also included.

NASA seeks to revive lost probe that traced solar storms

NASA Astrophysics Data System (ADS)

Voosen, Paul

2018-02-01

NASA's Imager for Magnetopause-to-Aurora Global Exploration (IMAGE), a satellite that failed in 2005, was recently discovered to be reactivated by an amateur astronomer. Until its demise, IMAGE provided unparalleled views of solar storms crashing into Earth's magnetosphere, a capability that has not been replaced since. The amateur astronomer was on the search for Zuma, a classified U.S. satellite that's believed to have failed after launch. He instead discovered IMAGE, broadcasting again, likely thanks to a reboot that occurred after its batteries drained during a past solar eclipse. NASA scientists are now working to communicate with the satellite in the hopes of reviving its six scientific instruments.

Dynamics of nitrate and chloride during storm events in agricultural catchments with different subsurface drainage intensity (Indiana, USA)

USDA-ARS?s Scientific Manuscript database

Grids of perforated pipe buried beneath many poorly drained agricultural fields in the Midwestern U.S. are believed to “short circuit” pools of nitrate-laden soil water and shallow groundwater directly into streams that eventually discharge to the Mississippi River. Although much is known about the ...

Field drains as a route of rapid nutrient export from agricultural land receiving biosolids.

PubMed

Heathwaite, A L; Burke, S P; Bolton, L

2006-07-15

We report research on the environmental risk of incidental nutrient transfers from land to water for biosolids amended soils. We show that subsurface (drainflow) pathways of P transport may result in significant concentrations, up to 10 mg total P l(-1), in the drainage network of an arable catchment when a P source (recent biosolids application) coincides with a significant and active transport pathway (rainfall event). However, the high P concentrations were short-lived, with drainage ditch total P concentrations returning to pre-storm concentrations within a few days of the storm event. In the case of the drainflow concentrations reported here, the results are unusual in that they describe an 'incidental event' for a groundwater catchment where such events might normally be expected to be rare owing to the capacity of the hydrological system to attenuate nutrient fluxes for highly adsorbed elements such as P. Consequently, there is a potential risk of P transfers to shallow groundwater systems. We suggest that the findings are not specific to biosolids-alone, which is a highly regulated industry, but that similar results may be anticipated had livestock waste or mineral fertilizer been applied, although the magnitude of losses may differ. The risk appears to be more one of timing and the availability of a rapid transport pathway than of P source.

Stochastic evaluation of annual micropollutant loads and their uncertainties in separate storm sewers.

PubMed

Hannouche, Ali; Chebbo, Ghassan; Joannis, Claude; Gasperi, Johnny; Gromaire, Marie-Christine; Moilleron, Régis; Barraud, Sylvie; Ruban, Véronique

2017-12-01

This article describes a stochastic method to calculate the annual pollutant loads and its application over several years at the outlet of three catchments drained by separate storm sewers. A stochastic methodology using Monte Carlo simulations is proposed for assessing annual pollutant load, as well as the associated uncertainties, from a few event sampling campaigns and/or continuous turbidity measurements (representative of the total suspended solids concentration (TSS)). Indeed, in the latter case, the proposed method takes into account the correlation between pollutants and TSS. The developed method was applied to data acquired within the French research project "INOGEV" (innovations for a sustainable management of urban water) at the outlet of three urban catchments drained by separate storm sewers. Ten or so event sampling campaigns for a large range of pollutants (46 pollutants and 2 conventional water quality parameters: TSS and total organic carbon (TOC)) are combined with hundreds of rainfall events for which, at least one among three continuously monitored parameters (rainfall intensity, flow rate, and turbidity) is available. Results obtained for the three catchments show that the annual pollutant loads can be estimated with uncertainties ranging from 10 to 60%, and the added value of turbidity monitoring for lowering the uncertainty is demonstrated. A low inter-annual and inter-site variability of pollutant loads, for many of studied pollutants, is observed with respect to the estimated uncertainties, and can be explained mainly by annual precipitation.

Metolachlor and its metabolites in tile drain and stream runoff in the canajoharie creek watershed

USGS Publications Warehouse

Phillips, P.J.; Wall, G.R.; Thurman, E.M.; Eckhardt, D.A.; Vanhoesen, J.

1999-01-01

Water samples collected during April-November 1997 from tile drains beneath cultivated fields in central New York indicate that two metabolites of the herbicide metolachlor-metolachlor ESA (ethanesulfonic acid) and OA (oxanilic acid) can persist in agricultural soils for 4 or more years after application and that fine-grained soils favor the transport of metolachlor ESA over metolachlor and metolachlor OA. Concentrations of metolachlor ESA from the tile drains ranged from 3.27 to 23.4 ??g/L (200 1800 times higher than those of metolachlor), metolachlor OA concentrations ranged from 1.14 to 13.5 ??g/L, and metolachlor concentrations ranged from less than 0.01 to 0.1 ??g/L. In the receiving stream, concentrations of metolachlor ESA were always below 0.6 ??g/L except during a November storm, when concentrations reached 0.85 ??g/L. Concentrations of metolachlor ESA in the stream were 2 45 times higher than those of metolachlor, reflecting the greater relative concentrations of metolachlor in surface water runoff than in tile drain runoff. These results are consistent with findings in other studies that acetanilide herbicide degredates are found in much higher concentrations than parent compounds in both surface water and groundwater.Water samples collected during April-November 1997 from tile drains beneath cultivated fields in central New York indicate that two metabolites of the herbicide metolachlor-metolachlor ESA (ethanesulfonic acid) and OA (oxanilic acid)-can persist in agricultural soils for 4 or more years after application and that fine-grained soils favor the transport of metolachlor ESA over metolachlor and metolachlor OA. Concentrations of metolachlor ESA from the tile drains ranged from 3.27 to 23.4 ??g/L (200-1800 times higher than those of metolachlor), metolachlor OA concentrations ranged from 1.14 to 13.5 ??g/L, and metolachlor concentrations ranged from less than 0.01 to 0.1 ??g/L. In the receiving stream, concentrations of metolachlor ESA were always below 0.6 ??g/L except during a November storm, when concentrations reached 0.85 ??g/L. Concentrations of metolachlor ESA in the stream were 2-45 times higher than those of metolachlor, reflecting the greater relative concentrations of metolachlor in surface water runoff than in tile drain runoff. These results are consistent with findings in other studies that acetanilide herbicide degredates are found in much higher concentrations than parent compounds in both surface water and groundwater.

Monitoring inland storm tide and flooding from Hurricane Irene along the Atlantic Coast of the United States, August 2011

USGS Publications Warehouse

McCallum, Brian E.; Painter, Jaime A.; Frantz, Eric R.

2012-01-01

The U.S. Geological Survey (USGS) deployed a temporary monitoring network of water-level sensors at 212 locations along the Atlantic coast from South Carolina to Maine during August 2011 to record the timing, areal extent, and magnitude of inland hurricane storm tide and coastal flooding generated by Hurricane Irene. Water-level sensor locations were selected to augment existing tide-gage networks to ensure adequate monitoring in areas forecasted to have substantial storm tide. As defined by the National Oceanic and Atmospheric Administration (NOAA; 2011a,b), storm tide is the water-level rise generated by a coastal storm as a result of the combination of storm surge and astronomical tide.

A Regional GPS Receiver Network For Monitoring Mid-latitude Total Electron Content During Storms

NASA Astrophysics Data System (ADS)

Vernon, A.; Cander, Lj. R.

A regional GPS receiver network has been used for monitoring mid-latitude total elec- tron content (TEC) during ionospheric storms at the current solar maximum. Differ- ent individual storms were examined to study how the temporal patterns of changes develop and how they are related to solar and geomagnetic activity for parameter de- scriptive of plasmaspheric-ionospheric ionisation. Use is then made of computer con- touring techniques to produce snapshot maps of TEC for different study cases. Com- parisons with the local ionosonde data at different phases of the storms enable the storm developments to be studied in detail.

NARX neural network Prediction of SYMH and ASYH indices for geomagnetic storms of solar cycle 24 including recent St. Patrick's day, 2015 storm

NASA Astrophysics Data System (ADS)

Bhaskar, A. T.; Vichare, G.

2017-12-01

Here, an attempt is made to develop a prediction model for SYMH and ASYH geomagnetic indices using Artificial Neural Network (ANN). SYMH and ASYH indices represent longitudinal symmetric and asymmetric component of the ring current. The ring current state depends on its past conditions therefore, it is necessary to consider its history for prediction. To account this effect Nonlinear Autoregressive Network with eXogenous inputs (NARX) is implemented. This network considers input history of 30 minutes and output feedback of 120 minutes. Solar wind parameters mainly velocity, density and interplanetary magnetic field are used as inputs. SYMH and ASYH indices during geomagnetic storms of 1998-2013, having minimum SYMH <-85 nT are used as the target for training two independent networks. We present the prediction of SYMH and ASYH indices during 9 geomagnetic storms of solar cycle 24 including the recent largest storm occurred on St. Patrick's day, 2015. The present prediction model reproduces the entire time profile of SYMH and ASYH indices along with small variations of 10-30 minutes to good extent within noise level, indicating significant contribution of interplanetary sources and past state of the magnetosphere. However, during the main phase of major storms, residuals (observed-modeled) are found to be large, suggesting influence of internal factors such as magnetospheric processes.

Healthcare4VideoStorm: Making Smart Decisions Based on Storm Metrics.

PubMed

Zhang, Weishan; Duan, Pengcheng; Chen, Xiufeng; Lu, Qinghua

2016-04-23

Storm-based stream processing is widely used for real-time large-scale distributed processing. Knowing the run-time status and ensuring performance is critical to providing expected dependability for some applications, e.g., continuous video processing for security surveillance. The existing scheduling strategies' granularity is too coarse to have good performance, and mainly considers network resources without computing resources while scheduling. In this paper, we propose Healthcare4Storm, a framework that finds Storm insights based on Storm metrics to gain knowledge from the health status of an application, finally ending up with smart scheduling decisions. It takes into account both network and computing resources and conducts scheduling at a fine-grained level using tuples instead of topologies. The comprehensive evaluation shows that the proposed framework has good performance and can improve the dependability of the Storm-based applications.

Auroral LSTIDs and SAR Arc Occurrences in Northern California During Geomagnetic Storms

NASA Astrophysics Data System (ADS)

Bhatt, A.; Kendall, E. A.

2015-12-01

A 630nm allsky imager has been operated for two years in northern California at the Hat Creek Radio Observatory. F-region airglow data captured by the imager ranges from approximately L=1.7 -2.7. Since installation of the imager several geomagnetic storms have occurred with varying intensities. Two main manifestations of the geomagnetic storms are observed in the 630 nm airglow data: large-scale traveling ionospheric disturbances that are launched from the auroral zone and Stable Auroral Red (SAR) arcs during more intense geomagnetic storms. We will present a statistical analysis of these storm-time phenomena in northern California for the past eighteen months. This imager is part of a larger all-sky imaging network across the continental United States, termed MANGO (Midlatitude All-sky-imaging Network for Geophysical Observations). Where available, we will add data from networked imagers located at similar L-shell in other states as well.

MANGO Imager Network Observations of Geomagnetic Storm Impact on Midlatitude 630 nm Airglow Emissions

NASA Astrophysics Data System (ADS)

Kendall, E. A.; Bhatt, A.

2017-12-01

The Midlatitude Allsky-imaging Network for GeoSpace Observations (MANGO) is a network of imagers filtered at 630 nm spread across the continental United States. MANGO is used to image large-scale airglow and aurora features and observes the generation, propagation, and dissipation of medium and large-scale wave activity in the subauroral, mid and low-latitude thermosphere. This network consists of seven all-sky imagers providing continuous coverage over the United States and extending south into Mexico. This network sees high levels of medium and large scale wave activity due to both neutral and geomagnetic storm forcing. The geomagnetic storm observations largely fall into two categories: Stable Auroral Red (SAR) arcs and Large-scale traveling ionospheric disturbances (LSTIDs). In addition, less-often observed effects include anomalous airglow brightening, bright swirls, and frozen-in traveling structures. We will present an analysis of multiple events observed over four years of MANGO network operation. We will provide both statistics on the cumulative observations and a case study of the "Memorial Day Storm" on May 27, 2017.

Aquatic Nitrate Retention at River Network Scales Across Flow Conditions Determined Using Nested In Situ Sensors

NASA Astrophysics Data System (ADS)

Wollheim, W. M.; Mulukutla, G. K.; Cook, C.; Carey, R. O.

2017-11-01

Nonpoint pollution sources are strongly influenced by hydrology and are therefore sensitive to climate variability. Some pollutants entering aquatic ecosystems, e.g., nitrate, can be mitigated by in-stream processes during transport through river networks. Whole river network nitrate retention is difficult to quantify with observations. High frequency, in situ nitrate sensors, deployed in nested locations within a single watershed, can improve estimates of both nonpoint inputs and aquatic retention at river network scales. We deployed a nested sensor network and associated sampling in the urbanizing Oyster River watershed in coastal New Hampshire, USA, to quantify storm event-scale loading and retention at network scales. An end member analysis used the relative behavior of reactive nitrate and conservative chloride to infer river network fate of nitrate. In the headwater catchments, nitrate and chloride concentrations are both increasingly diluted with increasing storm size. At the mouth of the watershed, chloride is also diluted, but nitrate tended to increase. The end member analysis suggests that this pattern is the result of high retention during small storms (51-78%) that declines to zero during large storms. Although high frequency nitrate sensors did not alter estimates of fluxes over seasonal time periods compared to less frequent grab sampling, they provide the ability to estimate nitrate flux versus storm size at event scales that is critical for such analyses. Nested sensor networks can improve understanding of the controls of both loading and network scale retention, and therefore also improve management of nonpoint source pollution.

Linkage of Rainfall-Runoff and Hurricane Storm Surge in Galveston Bay

NASA Astrophysics Data System (ADS)

Deitz, R.; Christian, J.; Wright, G.; Fang, N.; Bedient, P.

2012-12-01

In conjunction with the SSPEED Center, large rainfall events in the upper Gulf of Mexico are being studied in an effort to help design a surge gate to protect the Houston Ship Channel during hurricane events. The ship channel is the world's second largest petrochemical complex and the Coast Guard estimates that a one-month closure would have a $60 billion dollar impact on the national economy. In this effort, statistical design storms, such as the 24-hour PMP, as well as historical storms, like Hurricane Ike, Hurricane Katrina, and Hurricane Rita, are being simulated in a hydrologic/hydraulic model using radar and rain gauge data. VfloTM, a distributed hydrologic model, is being used to quantify the effect that storm size, intensity, and location has on timing and peak flows in the in the upper drainage area. These hydrographs were input to a hydraulic model with various storm surges from Galveston Bay. Results indicate that there is a double peak phenomenon with flows from the west draining days earlier than flows from the north. With storm surge typically lasting 36-48 hours, this indicates the flows from the west are interacting with the storm surge, whereas flows from the north would arrive once the storm surge is receding. Gate operations were optimized in the model to account for the relative timing of upland runoff and hurricane surge, and to quantify the capability of the gate structure to protect the Ship Channel industry.

Calibration and validation of the SWAT model for a forested watershed in coastal South Carolina

Treesearch

Devendra M. Amatya; Elizabeth B. Haley; Norman S. Levine; Timothy J. Callahan; Artur Radecki-Pawlik; Manoj K. Jha

2008-01-01

Modeling the hydrology of low-gradient coastal watersheds on shallow, poorly drained soils is a challenging task due to the complexities in watershed delineation, runoff generation processes and pathways, flooding, and submergence caused by tropical storms. The objective of the study is to calibrate and validate a GIS-based spatially-distributed hydrologic model, SWAT...

A non-conventional watershed partitioning method for semi-distributed hydrological modelling: the package ALADHYN

NASA Astrophysics Data System (ADS)

Menduni, Giovanni; Pagani, Alessandro; Rulli, Maria Cristina; Rosso, Renzo

2002-02-01

The extraction of the river network from a digital elevation model (DEM) plays a fundamental role in modelling spatially distributed hydrological processes. The present paper deals with a new two-step procedure based on the preliminary identification of an ideal drainage network (IDN) from contour lines through a variable mesh size, and the further extraction of the actual drainage network (AND) from the IDN using land morphology. The steepest downslope direction search is used to identify individual channels, which are further merged into a network path draining to a given node of the IDN. The contributing area, peaks and saddles are determined by means of a steepest upslope direction search. The basin area is thus partitioned into physically based finite elements enclosed by irregular polygons. Different methods, i.e. the constant and variable threshold area methods, the contour line curvature method, and a topologic method descending from the Hortonian ordering scheme, are used to extract the ADN from the IDN. The contour line curvature method is shown to provide the most appropriate method from a comparison with field surveys. Using the ADN one can model the hydrological response of any sub-basin using a semi-distributed approach. The model presented here combines storm abstraction by the SCS-CN method with surface runoff routing as a geomorphological dispersion process. This is modelled using the gamma instantaneous unit hydrograph as parameterized by river geomorphology. The results are implemented using a project-oriented software facility for the Analysis of LAnd Digital HYdrological Networks (ALADHYN).

Hurricane impacts on coastal wetlands: A half-century record of storm-generated features from Southern Louisiana

USGS Publications Warehouse

Morton, R.A.; Barras, J.A.

2011-01-01

Temporally and spatially repeated patterns of wetland erosion, deformation, and deposition are observed on remotely sensed images and in the field after hurricanes cross the coast of Louisiana. The diagnostic morphological wetland features are products of the coupling of high-velocity wind and storm-surge water and their interaction with the underlying, variably resistant, wetland vegetation and soils. Erosional signatures include construction of orthogonal-elongate ponds and amorphous ponds, pond expansion, plucked marsh, marsh denudation, and shoreline erosion. Post-storm gravity reflux of floodwater draining from the wetlands forms dendritic incisions around the pond margins and locally integrates drainage pathways forming braided channels. Depositional signatures include emplacement of broad zones of organic wrack on topographic highs and inorganic deposits of variable thicknesses and lateral extents in the form of shore-parallel sandy washover terraces and interior-marsh mud blankets. Deformational signatures primarily involve laterally compressed marsh and displaced marsh mats and balls. Prolonged water impoundment and marsh salinization also are common impacts associated with wetland flooding by extreme storms. Many of the wetland features become legacies that record prior storm impacts and locally influence subsequent storm-induced morphological changes. Wetland losses caused by hurricane impacts depend directly on impact duration, which is controlled by the diameter of hurricane-force winds, forward speed of the storm, and wetland distance over which the storm passes. Distinguishing between wetland losses caused by storm impacts and losses associated with long-term delta-plain processes is critical for accurate modeling and prediction of future conversion of land to open water. ?? Coastal Education & Research Foundation 2011.

Hurricane impacts on coastal wetlands: a half-century record of storm-generated features from southern Louisiana

USGS Publications Warehouse

Morton, Robert A.; Barras, John A.

2011-01-01

Temporally and spatially repeated patterns of wetland erosion, deformation, and deposition are observed on remotely sensed images and in the field after hurricanes cross the coast of Louisiana. The diagnostic morphological wetland features are products of the coupling of high-velocity wind and storm-surge water and their interaction with the underlying, variably resistant, wetland vegetation and soils. Erosional signatures include construction of orthogonal-elongate ponds and amorphous ponds, pond expansion, plucked marsh, marsh denudation, and shoreline erosion. Post-storm gravity reflux of floodwater draining from the wetlands forms dendritic incisions around the pond margins and locally integrates drainage pathways forming braided channels. Depositional signatures include emplacement of broad zones of organic wrack on topographic highs and inorganic deposits of variable thicknesses and lateral extents in the form of shore-parallel sandy washover terraces and interior-marsh mud blankets. Deformational signatures primarily involve laterally compressed marsh and displaced marsh mats and balls. Prolonged water impoundment and marsh salinization also are common impacts associated with wetland flooding by extreme storms. Many of the wetland features become legacies that record prior storm impacts and locally influence subsequent storm-induced morphological changes. Wetland losses caused by hurricane impacts depend directly on impact duration, which is controlled by the diameter of hurricane-force winds, forward speed of the storm, and wetland distance over which the storm passes. Distinguishing between wetland losses caused by storm impacts and losses associated with long-term delta-plain processes is critical for accurate modeling and prediction of future conversion of land to open water.

Role of antecedent conditions on nitrogen and phosphorus mobilisation observed in a lowland arable catchment in eastern England: insights from high-frequency monitoring

NASA Astrophysics Data System (ADS)

Outram, Faye; Hiscock, Kevin; Dugdale, Stephen; Lovett, Andrew

2015-04-01

In order to reduce annual riverine loadings of nutrients which are responsible for degradation of ecosystems downstream and in near coastal areas, it is important to first understand the mobilisation and pathways responsible for transporting them from source to river and how these pathways vary in space and time. The Blackwater tributary of the River Wensum in Norfolk, England, has been equipped with a sensor network as part of the Demonstration Test Catchments project, which has the aim of reducing pollution from agriculture to river systems whilst maintaining food security by the trial of mitigation measures on working farms at the sub-catchment level. The River Wensum is a lowland chalk catchment with intensive arable agriculture and high occurrence of tile drainage on heavier soils. Three hydrological years of high-frequency data have been gathered in the Blackwater since October 2011, including rainfall, half hourly measurements of discharge and groundwater level coupled with hydrochemical parameters including nitrate, total phosphorus (TP) and total reactive phosphorus (TRP). In the three years of data collection, there were distinct departures from long-term rainfall averages as the winter of 2011-12 was extremely dry following a drought from the previous hydrological year, followed by a summer which was unseasonably wet, which continued into the following winter. The relationship between rainfall, storage and discharge was found to be complex, which in turn had an impact on the dominant controls transporting nutrients from the landscape to the river network. Thirty three storms occurred throughout the three year period which have been analysed in the context of the range of hydrometeorological conditions observed throughout the dataset. Discharge-concentration hysteretic responses of nitrogen, TP and TRP have been used alongside statistical analysis of storm characteristics including antecedent hydrological conditions. The nitrate storm response showed distinct seasonal patterns which were greatly impacted by the activation of tile drain flow throughout the winter period and during the fertiliser application window between March-May, with the dry winter in 2011-12 standing apart from the more 'typical' years. Four different storm response categories were identified for nitrate according to dominant flow pathways. The phosphorus response was far less uniform throughout the study period, showing patterns of exhaustion with successive events. Both nitrate and phosphorus loads were disproportionate to flow volume in storm events which occurred after significant dry periods. The data show the importance of antecedent conditions in the storage, mobilisation and transport of nitrogen and phosphorus in agricultural catchments which has important implications for the conceptual understanding of catchment functioning and environmental management.

Ensemble Sensitivity Analysis of a Severe Downslope Windstorm in Complex Terrain: Implications for Forecast Predictability Scales and Targeted Observing Networks

DTIC Science & Technology

2013-09-01

wave breaking (NWB) and eight wave breaking (WB) storms are shown...studies, and it follows that the wind storm characteristics are likely more three dimensional as well. For the purposes of this study, a severe DSWS is...regularly using the HWAS network at USAFA since its installation in 2004. A careful examination of these events reveals downslope storms that are

Isotopic mixing model for quantifying contributions of soil water and groundwater in subsurface ('tile') drainage

NASA Astrophysics Data System (ADS)

Kennedy, C. D.; Gall, H.; Jafvert, C. T.; Bowen, G. J.

2010-12-01

Subsurface (‘tile’) drainage, consisting of buried grids of perforated pipe, has provided a means of converting millions of acres of poorly drained soils in the Midwestern U.S. into fertile cropland. However, by altering pathways and rates of soil water and groundwater movement through agricultural lands, this practice may accelerate the loss of nitrate and other agrochemicals. To better understand the hydrological controls on nitrogen dynamics in artificially drained agricultural watersheds, a field sampling program has been established at the Animal Science Research and Education Center (ASREC) at Purdue University (West Lafayette, Indiana) to (1) measure precipitation amount, tile flow, and water-table elevation, and (2) collect water samples for analysis of nitrate, major ions, and oxygen isotope ratios in precipitation, tile drainage, shallow (1 m) and deep (3 m) groundwater, and soil water during storm events. Preliminary physical, chemical, and isotopic data collected at the ASREC show a coincident timing of peak storm ‘event water’ and peak nitrate flux in tile drainage, suggesting significant routing of infiltrating event water. In this work, we aim to refine our understanding of tile drainage at the ASREC by developing a mixing model for partitioning contributions of soil water and groundwater in tile drainage during several storm runoff events ranging in precipitation intensity and coinciding with varying antecedent soil moisture conditions. The results of our model will describe tile drainage in terms of its hydrological components, soil water and groundwater, which in turn will provide a means of incorporating the effects of tile drainage in surface/subsurface hydrological transport models.

20. VIEW OF NORTH AND EAST ELEVATIONS. HERE, THE CANAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. VIEW OF NORTH AND EAST ELEVATIONS. HERE, THE CANAL HAS BEEN DRAINED, ALLOWING A RARE VIEW OF THE HEADGATES. THE MILL'S NORTH BASEMENT WALL WAS CLOSED UP WITH CINDER BLOCK AFTER A STORM BROUGHT WATER POWER TO AN END IN 1970. Photographer: Louise Taft Cawood, July 1986 - Alexander's Grist Mill, Lock 37 on Ohio & Erie Canal, South of Cleveland, Valley View, Cuyahoga County, OH

Urban drainage control applying rational method and geographic information technologies

NASA Astrophysics Data System (ADS)

Aldalur, Beatriz; Campo, Alicia; Fernández, Sandra

2013-09-01

The objective of this study is to develop a method of controlling urban drainages in the town of Ingeniero White motivated by the problems arising as a result of floods, water logging and the combination of southeasterly and high tides. A Rational Method was applied to control urban watersheds and used tools of Geographic Information Technology (GIT). A Geographic Information System was developed on the basis of 28 panchromatic aerial photographs of 2005. They were georeferenced with control points measured with Global Positioning Systems (basin: 6 km2). Flow rates of basins and sub-basins were calculated and it was verified that the existing open channels have a low slope with the presence of permanent water and generate stagnation of water favored by the presence of trash. It is proposed for the output of storm drains, the use of an existing channel to evacuate the flow. The solution proposed in this work is complemented by the placement of three pumping stations: one on a channel to drain rain water which will allow the drain of the excess water from the lower area where is located the Ingeniero White city and the two others that will drain the excess liquid from the port area.

Classifying hydrological events to quantify their impact on nitrate leaching across three spatial scales

NASA Astrophysics Data System (ADS)

Bauwe, Andreas; Tiemeyer, Bärbel; Kahle, Petra; Lennartz, Bernd

2015-04-01

Nitrate is one of the most important sources of pollution for surface waters in tile-drained agricultural areas. In order to develop appropriate management strategies to reduce nitrate losses, it is crucial to first understand the underlying hydrological processes. In this study, we used Principle Component Analysis (PCA) and Linear Discriminant Analysis (LDA) to analyze 212 storm events between 2004 and 2011 across three spatial scales (collector drain, ditch, and brook) to identify the controlling factors for hydrograph response characteristics and their influence on nitrate concentration patterns. Our results showed that the 212 hydrological events can be classified into six different types: summer events (28%), snow-dominated events (10%), events controlled by rainfall duration (16%), rainfall totals (8%), dry antecedent conditions (10%), and events controlled by wet antecedent conditions (14%). The relatively large number of unclassified events (15%) demonstrated the difficulty in separating event types due to mutually influencing variables. NO3-N concentrations showed a remarkably consistent pattern during the discharge events regardless of event type, with minima at the beginning, increasing concentrations at the rising limb, and maxima around peak discharge. However, the level of NO3-N concentrations varied notably among the event types. The highest average NO3-N concentrations were found for events controlled by rainfall totals (NO3-N=17.1 mg/l), events controlled by wet antecedent conditions (NO3-N=17.1 mg/l), and snowmelt (NO3-N=15.2 mg/l). Average maximum NO3-N concentrations were significantly lower during summer events (NO3-N=10.2 mg/l) and events controlled by dry antecedent conditions (NO3-N=11.7 mg/l). The results have furthermore shown that similar hydrological and biogeochemical processes determine the hydrograph and NO3-N response on storm events at various spatial scales. The management of tile-drained agricultural land to reduce NO3-N losses should focus explicitly on flow events and, more specifically, active management should preferably be conducted in the winter season for discharge events after snowmelt, after heavy rain storms and when the soil moisture conditions are wet.

Spotter's Guide for Identifying and Reporting Severe Local Storms.

ERIC Educational Resources Information Center

National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

This guide is designed to assist personnel working in the National Weather Service's Severe Local Storm Spotter Networks in identifying and reporting severe local storms. Provided are pictures of cloud types for severe storms including tornadoes, hail, thunder, lightning, heavy rains, and waterspouts. Instructions for key indications to watch for…

Simulating Geomagnetically Induced Currents in the Irish Power Network

NASA Astrophysics Data System (ADS)

Jones, A. G.; Blake, S. P.; Gallagher, P.; McCauley, J.; Hogg, C.; Beggan, C.; Thomson, A. W. P.; Kelly, G.; Walsh, S.

2014-12-01

Geomagnetic storms are known to cause geomagnetically induced currents (GICs) which can damage or destroy transformers on power grids. Previous studies have examined the vulnerability of power networks in countries such as the UK, New Zealand, Canada and South Africa. Here we describe the application of a British Geological Survey (BGS) thin-sheet conductivity model to compute the geo-electric field from the variation of the magnetic field, in order to better quantify the risk of space weather to Ireland's power network. This was achieved using DIAS magnetotelluric data from across Ireland. As part of a near-real-time warning package for Eirgrid (who oversee Ireland's transmission network), severe storm events such as the Halloween 2003 storm and the corresponding GIC flows at transformers are simulated.

Evaluation of a Socio-Hydrologic Model for the Rebuilding of Biloxi, Mississippi

NASA Astrophysics Data System (ADS)

Calhoun, J. L.; O'Donnell, F. C.; Burton, C. G.

2017-12-01

In August 2005, Hurricane Katrina ripped through the Gulf Coast of the United States causing billions in damage. The storm cost the City of Biloxi, Mississippi $355 million in infrastructure repair, which is being constructed with funding from the Federal Emergency Management Agency (FEMA). Approximately 30% of the city's storm systems including storm drains, bridges and culverts are being replaced and updated utilizing FEMA Hazard Mitigation funding to lessen the impact of future natural disasters. The infrastructure is being upgraded from conveying a 4% annual chance storm event to a 1% annual chance storm event. An extensive socio-economic data set of the impacts of Hurricane Katrina along the Mississippi Gulf Coast was used to analyze recovery in the area. The recovery data set assessed the area directly after the storm in 2005 thru 2010 with an analysis of recovery five years after the storm. This study uses a dynamic socio-hydrologic model with modifications to relate the change in flow capacity of engineered structures and socio-economic processes. The results will be used to assess the hypothesis that raising flood protection increases the base flood elevation levels and therefore requires a higher level of flood protection. The increase in flood protect eases the fears of the community leading them to not require additional flood protection when developing in flood prone areas and strengthening the socio-hydrologic association. The results will also be evaluated to create a tool for the City of Biloxi to improve their resilience from future hurricanes and storm surge events.

Modeling geomagnetic induced currents in Australian power networks

NASA Astrophysics Data System (ADS)

Marshall, R. A.; Kelly, A.; Van Der Walt, T.; Honecker, A.; Ong, C.; Mikkelsen, D.; Spierings, A.; Ivanovich, G.; Yoshikawa, A.

2017-07-01

Geomagnetic induced currents (GICs) have been considered an issue for high-latitude power networks for some decades. More recently, GICs have been observed and studied in power networks located in lower latitude regions. This paper presents the results of a model aimed at predicting and understanding the impact of geomagnetic storms on power networks in Australia, with particular focus on the Queensland and Tasmanian networks. The model incorporates a "geoelectric field" determined using a plane wave magnetic field incident on a uniform conducting Earth, and the network model developed by Lehtinen and Pirjola (1985). Model results for two intense geomagnetic storms of solar cycle 24 are compared with transformer neutral monitors at three locations within the Queensland network and one location within the Tasmanian network. The model is then used to assess the impacts of the superintense geomagnetic storm of 29-31 October 2003 on the flow of GICs within these networks. The model results show good correlation with the observations with coefficients ranging from 0.73 to 0.96 across the observing sites. For Queensland, modeled GIC magnitudes during the superstorm of 29-31 October 2003 exceed 40 A with the larger GICs occurring in the south-east section of the network. Modeled GICs in Tasmania for the same storm do not exceed 30 A. The larger distance spans and general east-west alignment of the southern section of the Queensland network, in conjunction with some relatively low branch resistance values, result in larger modeled GICs despite Queensland being a lower latitude network than Tasmania.

Extreme storms, sea level rise, and coastal change: implications for infrastructure reliability in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Anarde, K.; Kameshwar, S.; Irza, N.; Lorenzo-Trueba, J.; Nittrouer, J. A.; Padgett, J.; Bedient, P. B.

2016-12-01

Predicting coastal infrastructure reliability during hurricane events is important for risk-based design and disaster planning, such as delineating viable emergency response routes. Previous research has focused on either infrastructure vulnerability to coastal flooding or the impact of changing sea level and landforms on surge dynamics. Here we investigate the combined impact of sea level, morphology, and coastal flooding on the reliability of highway bridges - the only access points between barrier islands and mainland communities - during future extreme storms. We forward model coastal flooding for static projections of geomorphic change using ADCIRC+SWAN. First-order parameters that are adjusted include sea level and elevation. These are varied for each storm simulation to evaluate relative impact on the reliability of bridges surrounding Freeport, TX. Simulated storms include both synthetic and historical events, which are classified by intensity using the storm's integrated kinetic energy, a metric for surge generation potential. Reliability is estimated through probability of failure - given wave and surge loads - and time inundated. Findings include that: 1) bridge reliability scales inversely with surge height, and 2) sea level rise reduces bridge reliability due to a monotonic increase in surge height. The impact of a shifting landscape on bridge reliability is more complex: barrier island rollback can increase or decrease inundation times for storms of different intensity due to changes in wind-setup and back-barrier bay interactions. Initial storm surge readily inundates the coastal landscape during large intensity storms, however the draining of inland bays following storm passage is significantly impeded by the barrier. From a coastal engineering standpoint, we determine that to protect critical infrastructure, efforts now implemented that nourish low-lying barriers may be enhanced by also armoring back-bay coastlines and elevating bridge approach ramps.

Spatial analysis of storm depths from an Arizona raingage network

NASA Technical Reports Server (NTRS)

Fennessey, N. M.; Eagleson, P. S.; Qinliang, W.; Rodriguez-Iturbe, I.

1986-01-01

Eight years of summer rainstorm observations are analyzed by a dense network of 93 raingages operated by the U.S. Department of Agriculture, Agricultural Research Service, in the 150 km Walnut Gulch experimental catchment near Tucson, Arizona. Storms are defined by the total depths collected at each raingage during the noon-to-noon period for which there was depth recorded at any of the gages. For each of the resulting 428 storm days, the gage depths are interpolated onto a dense grid and the resulting random field analyzed to obtain moments, isohyetal plots, spatial correlation function, variance function, and the spatial distribution of storm depth.

A multi-scale hybrid neural network retrieval model for dust storm detection, a study in Asia

NASA Astrophysics Data System (ADS)

Wong, Man Sing; Xiao, Fei; Nichol, Janet; Fung, Jimmy; Kim, Jhoon; Campbell, James; Chan, P. W.

2015-05-01

Dust storms are known to have adverse effects on human health and significant impact on weather, air quality, hydrological cycle, and ecosystem. Atmospheric dust loading is also one of the large uncertainties in global climate modeling, due to its significant impact on the radiation budget and atmospheric stability. Observations of dust storms in humid tropical south China (e.g. Hong Kong), are challenging due to high industrial pollution from the nearby Pearl River Delta region. This study develops a method for dust storm detection by combining ground station observations (PM10 concentration, AERONET data), geostationary satellite images (MTSAT), and numerical weather and climatic forecasting products (WRF/Chem). The method is based on a hybrid neural network (NN) retrieval model for two scales: (i) a NN model for near real-time detection of dust storms at broader regional scale; (ii) a NN model for detailed dust storm mapping for Hong Kong and Taiwan. A feed-forward multilayer perceptron (MLP) NN, trained using back propagation (BP) algorithm, was developed and validated by the k-fold cross validation approach. The accuracy of the near real-time detection MLP-BP network is 96.6%, and the accuracies for the detailed MLP-BP neural network for Hong Kong and Taiwan is 74.8%. This newly automated multi-scale hybrid method can be used to give advance near real-time mapping of dust storms for environmental authorities and the public. It is also beneficial for identifying spatial locations of adverse air quality conditions, and estimates of low visibility associated with dust events for port and airport authorities.

Tracking Changes in Dissolved Organic Matter Patterns in Perennial Headwater Streams Throughout a Hydrologic Year Using In-situ Sensors and Optical Properties

NASA Astrophysics Data System (ADS)

Armstrong, A.; Epting, S.; Hosen, J. D.; Palmer, M.

2015-12-01

Dissolved organic matter (DOM) plays a central role in freshwater streams but key questions remain unanswered about temporal patterns in its quantity and composition. DOM in perennial streams in the temperate zone is a complex mixture reflecting a variety of sources such as leached plant material, organic matter from surrounding soils, and microbial processes in the streams themselves. Headwater perennial streams in the Tuckahoe Creek watershed of the Atlantic coastal plain (Maryland, USA) drain a mosaic of land cover types including row crops, forests, and both forested and marshy small depressional wetlands. Wetland-stream surface hydrologic connections generally occur between mid-fall and late spring, coinciding with peak wetland hydrologic expression (i.e. highest groundwater levels and surface inundation extent). When inundated, these wetlands contain high DOM concentrations, and surface connections may serve as conduits for downstream export. We hypothesized that changes in wetland-stream surface hydrologic connectivity would affect patterns of DOM concentration and composition in these streams. We deployed 6 sondes equipped with fluorescent DOM sensors in 4 perennial streams, 1 forested wetland, and the larger downstream channel draining all study sites for the 2015 water year. The 4 headwater streams drain areas containing forested wetlands and have documented temporary channel connections. Combined with baseflow and stormflow sampling, the sondes provided 15 minute estimates of dissolved organic carbon (DOC) concentrations. This resolution provided insights into patterns of DOC concentration across temporal scales from daily rhythms to seasonal changes, during both baseflow and storm conditions. Discrete measurements of absorbance and fluorescence provided information about DOM composition throughout the study. Together these measurements give a detailed record of DOM dynamics in multiple perennial headwater streams for an entire year. This information could inform future studies, such as investigations into stream network scale thresholds in DOM cycling, carbon cycling modelling for the study region, or understanding the impact of wetlands sometimes considered geographically isolated on downstream ecosystems.

Experimental study of hydraulics and sediment capture efficiency in catchbasins.

PubMed

Tang, Yangbo; Zhu, David Z; Rajaratnam, N; van Duin, Bert

2016-12-01

Catchbasins (also known as gully pot in the UK and Australia) are used to receive surface runoff and drain the stormwater into storm sewers. The recent interest in catchbasins is to improve their effectiveness in removing sediments in stormwater. An experimental study was conducted to examine the hydraulic features and sediment capture efficiency in catchbasins, with and without a bottom sump. A sump basin is found to increase the sediment capture efficiency significantly. The effect of inlet control devices, which are commonly used to control the amount of flow into the downstream storm sewer system, is also studied. These devices will increase the water depth in the catchbasin and increase the sediment capture efficiency. Equations are developed for predicting the sediment capture efficiency in catchbasins.

Curve number derivation for watersheds draining two headwater streams in lower coastal plain South Carolina, USA

Treesearch

Thomas H. Epps; Daniel R. Hitchcock; Anand D. Jayakaran; Drake R. Loflin; Thomas M. Williams; Devendra M. Amatya

2013-01-01

The objective of this study was to assess curve number (CN) values derived for two forested headwater catchments in the Lower Coastal Plain (LCP) of South Carolina using a three-year period of storm event rainfall and runoff data in comparison with results obtained from CN method calculations. Derived CNs from rainfall/runoff pairs ranged from 46 to 90 for the Upper...

Transport of bedload sediment and channel morphology of a southeast Alaska stream.

Treesearch

Margaret A. Estep; Robert L. Beschta

1985-01-01

During 1980-81, transport of bedload sediment and channel morphology were determined at Trap Bay Creek, a third-order stream that drains a 13.5-square kilometer watershed on Chichagof island in southeast Alaska. Bedload sediment was sampled for 10 storms: peak flows ranged from 0.6 to 19.0 cubic meters per second, and transport rates ranged from 4 to 4400 kilograms per...

Storm Event Suspended Sediment-Discharge Hysteresis and Controls in Agricultural Watersheds: Implications for Watershed Scale Sediment Management.

PubMed

Sherriff, Sophie C; Rowan, John S; Fenton, Owen; Jordan, Philip; Melland, Alice R; Mellander, Per-Erik; hUallacháin, Daire Ó

2016-02-16

Within agricultural watersheds suspended sediment-discharge hysteresis during storm events is commonly used to indicate dominant sediment sources and pathways. However, availability of high-resolution data, qualitative metrics, longevity of records, and simultaneous multiwatershed analyses has limited the efficacy of hysteresis as a sediment management tool. This two year study utilizes a quantitative hysteresis index from high-resolution suspended sediment and discharge data to assess fluctuations in sediment source location, delivery mechanisms and export efficiency in three intensively farmed watersheds during events over time. Flow-weighted event sediment export was further considered using multivariate techniques to delineate rainfall, stream hydrology, and antecedent moisture controls on sediment origins. Watersheds with low permeability (moderately- or poorly drained soils) with good surface hydrological connectivity, therefore, had contrasting hysteresis due to source location (hillslope versus channel bank). The well-drained watershed with reduced connectivity exported less sediment but, when watershed connectivity was established, the largest event sediment load of all watersheds occurred. Event sediment export was elevated in arable watersheds when low groundcover was coupled with high connectivity, whereas in the grassland watershed, export was attributed to wetter weather only. Hysteresis analysis successfully indicated contrasting seasonality, connectivity and source availability and is a useful tool to identify watershed specific sediment management practices.

Monitoring the Storm Tide of Hurricane Wilma in Southwestern Florida, October 2005

USGS Publications Warehouse

Soderqvist, Lars E.; Byrne, Michael J.

2007-01-01

Temporary monitoring stations employing non-vented pressure transducers were used to augment an existing U.S. Geological Survey coastal monitoring network to document the inland water levels related to the storm tide of Hurricane Wilma on the southwestern coast of Florida. On October 22, 2005, an experimental network consisting of 30 temporary stations was deployed over 90 miles of coastline to record the magnitude, extent, and timing of hurricane storm tide and coastal flooding. Sensors were programmed to record time, temperature, and barometric or water pressure. Water pressure was adjusted for changes in barometric pressure and salinity, and then converted to feet of water above the sensor. Elevation surveys using optical levels were conducted to reference storm tide water-level data and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). Storm tide water levels more than 5 feet above NAVD 88 were recorded by sensors at several locations along the southwestern Florida coast. Temporary storm tide monitoring stations used for this effort have demonstrated their value in: (1) furthering the understanding of storm tide by allowing the U.S. Geological Survey to extend the scope of data collection beyond that of existing networks, and (2) serving as backup data collection at existing monitoring stations by utilizing nearby structures that are more likely to survive a major hurricane.

Impacts of land cover changes on hurricane storm surge in the lower Chesapeake Bay

NASA Astrophysics Data System (ADS)

Denton, M.; Lawler, S.; Ferreira, C.

2013-12-01

The Chesapeake Bay is the largest estuary in the United States with more than 150 rivers draining into the bay's tidal wetlands. Coastal wetlands and vegetation play an important role in shaping the hydrodynamics of storm surge events by retaining water and slowing the propagation of storm surge. In this way coastal wetlands act as a natural barrier to inland flooding, particularly against less intense storms. Threats to wetlands come from both land development (residential or commercial/industrial) and sea level rise. The lower region of the Chesapeake Bay near its outlet is especially vulnerable to flooding from Atlantic storm surge brought in by hurricanes, tropical storms and nor'easters (e.g., hurricanes Isabel [2003] and Sandy [2012]). This region is also intensely developed with nearly 1.7 million residents within the greater Hampton Roads metropolitan area. Anthropogenic changes to land cover in the lower bay can directly impact basin drainage and storm surge propagation with impacts reaching beyond the immediate coastal zone to affect flooding in inland areas. While construction of seawall barriers around population centers may provide storm surge protection to a specifically defined area, these barriers deflect storm surge rather than attenuate it, underscoring the importance of wetlands. To analyze these impacts a framework was developed combining numerical simulations with a detailed hydrodynamic characterization of flow through coastal wetland areas. Storm surges were calculated using a hydrodynamic model (ADCIRC) coupled to a wave model (SWAN) forced by an asymmetric hurricane vortex model using the FEMA region 3 unstructured mesh (2.3 million nodes) under a High Performance Computing (HPC) environment. Multiple model simulations were performed using historical hurricanes data and hypothetical storms to compare the predicted storm surge inundation with various levels of wetland reduction and/or beach hardening. These data were combined and overlaid with a geospatial inventory of critical infrastructure assets to evaluate the potential for storm damage associated with each level of wetland reduction. This poster will present quantitative analyses of the benefits and losses regarding storm surge inundation and damage from land cover changes in the study region.

Prediction of Sym-H index by NARX neural network from IMF and solar wind data

NASA Astrophysics Data System (ADS)

Cai, L.; Ma, S.-Y.; Liu, R.-S.; Schlegel, K.; Zhou, Y.-L.; Luehr, H.

2009-04-01

Similar to Dst, the Sym-H index is also an indicator of magnetic storm intensity, but having distinct advantage of higher time-resolution. In this study an artificial neural network (ANN) of Nonlinear Auto Regressive with eXogenous inputs (NARX) has been developed to predict for the first time Sym-H index from solar wind and IMF parameters. In total 73 great storm events during 1998 to 2006 are used, out of which 67 are selected to train the network and the other 6 samples including 2 super-storms for test. The newly developed NARX model shows much better capability than usual BP and Elman network in Sym-H prediction. When using IMF Bz, By and total B with a history length of 90 minutes along with solar wind proton density Np and velocity Vsw as the original external inputs of the ANN to predict Sym-H index one hour later, the cross-correlation between NARX network predicted and Kyoto observed Sym-H is 0.95 for the 6 test storms as a whole, even as high as 0.95 and 0.98 respectively for the two super-storms. This excellent performance of the NARX model can mainly be attributed to a feedback from the output neuron with a suitable length of about 120 min. to the external input. It is such a feedback that makes the ring current status properly brought into effect in the prediction of storm-time Sym-H index by our NARX network. Furthermore, different parameter combinations with different history length (70 to 120 min.) for IMF and solar wind data as external inputs are examined along with different hidden neuron number. It is found that the NARX network with 10 hidden units and with 100 min. length of Bz, Np and Vsw as external inputs provides the best results in Sym-H prediction. Besides, efforts have also been made to predict Sym-H longer time ahead, showing that the NARX network can predict Sym-H index 180 min. ahead with correlation coefficient of 0.94 between predicted and observed Sym-H and RMSE less than 19 nT for the 6 test samples.

Measurements of coastal storm surge by the U.S. Geological Survey

USGS Publications Warehouse

DelCharco, Michael J.

1998-01-01

In the wake of a storm, local, state, and federal emergency planners needed storm surge elevation data as quickly as possible. These data are used by officials to decide what areas are in the greatest need of assistance and what areas qualify for special designations. To accelerate the pace at which storm surge data can be gathered and released, the US geological survey (USGC) has established a network of coastal water elevation gages that are linked to satellite networks. These data are made available in real-time on the World Wide Web. While Internet access is usually fast and reliable, this process can be augmented by cellular phone, two-way radio, and other data communication techniques.

The variability of pH in convective storms

Treesearch

Richard G. Semonin

1976-01-01

The rainwater pH was measured in a total of 22 storms which occurred in 1972 and 1974 in the METROMEX (METROpolitan Meteorological EXperiment) rainwater sampling network. The network consists of 81 collectors in an area of 1800 km² over and east of St. Louis, Missouri. The data set is composed of dry...

Storm-scale dynamics of bacterial community composition in throughfall and stemflow

NASA Astrophysics Data System (ADS)

Van Stan, J. T., II; Teachey, M. E.; Pound, P.; Ottesen, E. A.

2017-12-01

Transport of bacteria between ecosystem spheres can significantly affect microbially-mediated biogeochemical processes. During rainfall, there is a large, temporally-concentrated exchange of bacteria between the forest phyllosphere and the pedosphere by rain dripping from canopy surfaces, as throughfall (TF), and draining to the stem, as stemflow (SF). Many phyllosphere bacteria possibly transported by TF and SF have been linked to important litter and soil processes (like cyanobacteria and actinobacteria). Despite this, no work has applied high throughput DNA sequencing to assess the community composition of bacteria transported by TF and SF. We characterized bacterial community composition for TF and SF from an epiphyte-laden (Tillandsia usneoides L., Spanish moss) southern live oak (Quercus virginiana) forest in southeastern Georgia (USA) to address two hypotheses: that bacterial community composition will differ between (1) TF and SF, and (2) TF sampled beneath bare and epiphyte-laden canopy. Variability in family-level bacterial abundance, Bray-Curtis dissimilarity, and Shannon diversity index was greater between storms than between net rainfall fluxes. In fact, TF and SF bacterial communities were relatively similar for individual storms and may be driven by pre-storm atmospheric deposition rather than the communities affixed to leaves, bark, and epiphyte surfaces.

Surface runoff and subsurface tile drain losses of neonicotinoids and companion herbicides at edge-of-field.

PubMed

Chrétien, François; Giroux, Isabelle; Thériault, Georges; Gagnon, Patrick; Corriveau, Julie

2017-05-01

With their application as seed coatings, the use of neonicotinoid insecticides increased dramatically during the last decade. They are now frequently detected in aquatic ecosystems at concentrations susceptible to harm aquatic invertebrates at individual and population levels. This study intent was to document surface runoff and subsurface tile drain losses of two common neonicotinoids (thiamethoxam and clothianidin) compared to those of companion herbicides (atrazine, glyphosate, S-metolachlor and mesotrione) at the edge of a 22.5-ha field under a corn-soybean rotation. A total of 14 surface runoff and tile drain discharge events were sampled over two years. Events and annual unit mass losses were computed using flow-weighted concentrations and total surface runoff and tile drain flow volumes. Detection frequencies close to 100% in edge-of-field surface runoff and tile drain water samples were observed for thiamethoxam and clothianidin even though only thiamethoxam had been applied in the first year. In 2014, thiamethoxam median concentrations in surface runoff and tile drain samples were respectively 0.46 and 0.16 μg/L, while respective maximum concentrations of 2.20 and 0.44 μg/L were measured in surface runoff and tile drain samples during the first post-seeding storm event. For clothianidin, median concentrations in surface runoff and tile drain samples were 0.02 and 0.01, μg/L, and respective maximum concentrations were 0.07 μg/L and 0.05 μg/L. Surface runoff and tile drain discharge were key transport mechanisms with similar contributions of 53 and 47% of measured mass losses, respectively. Even if thiamethoxam was applied at a relatively low rate and had a low mass exportation value (0.3%), the relative toxicity was one to two orders of magnitude higher than those of the other chemicals applied in 2014 and 2015. Companion herbicides, except glyphosate in tile drains, exceeded their water quality guideline during one sampling campaign after application but rapidly resumed below these limits. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Detection and Prediction of Hail Storms in Satellite Imagery using Deep Learning

NASA Astrophysics Data System (ADS)

Pullman, M.; Gurung, I.; Ramachandran, R.; Maskey, M.

2017-12-01

Natural hazards, such as damaging hail storms, dramatically disrupt both industry and agriculture, having significant socio-economic impacts in the United States. In 2016, hail was responsible for 3.5 billion and 23 million dollars in damage to property and crops, respectively, making it the second costliest 2016 weather phenomenon in the United States. The destructive nature and high cost of hail storms has driven research into the development of more accurate hail-prediction algorithms in an effort to mitigate societal impacts. Recently, weather forecasting efforts have turned to deep learning neural networks because neural networks can more effectively model complex, nonlinear, dynamical phenomenon that exist in large datasets through multiple stages of transformation and representation. In an effort to improve hail-prediction techniques, we propose a deep learning technique that leverages satellite imagery to detect and predict the occurrence of hail storms. The technique is applied to satellite imagery from 2006 to 2016 for the contiguous United States and incorporates hail reports obtained from the National Center for Environmental Information Storm Events Database for training and validation purposes. In this presentation, we describe a novel approach to predicting hail via a neural network model that creates a large labeled dataset of hail storms, the accuracy and results of the model, and its applications for improving hail forecasting.

An Energy-Efficient Cluster-Based Vehicle Detection on Road Network Using Intention Numeration Method

PubMed Central

Devasenapathy, Deepa; Kannan, Kathiravan

2015-01-01

The traffic in the road network is progressively increasing at a greater extent. Good knowledge of network traffic can minimize congestions using information pertaining to road network obtained with the aid of communal callers, pavement detectors, and so on. Using these methods, low featured information is generated with respect to the user in the road network. Although the existing schemes obtain urban traffic information, they fail to calculate the energy drain rate of nodes and to locate equilibrium between the overhead and quality of the routing protocol that renders a great challenge. Thus, an energy-efficient cluster-based vehicle detection in road network using the intention numeration method (CVDRN-IN) is developed. Initially, sensor nodes that detect a vehicle are grouped into separate clusters. Further, we approximate the strength of the node drain rate for a cluster using polynomial regression function. In addition, the total node energy is estimated by taking the integral over the area. Finally, enhanced data aggregation is performed to reduce the amount of data transmission using digital signature tree. The experimental performance is evaluated with Dodgers loop sensor data set from UCI repository and the performance evaluation outperforms existing work on energy consumption, clustering efficiency, and node drain rate. PMID:25793221

An energy-efficient cluster-based vehicle detection on road network using intention numeration method.

PubMed

Devasenapathy, Deepa; Kannan, Kathiravan

2015-01-01

The traffic in the road network is progressively increasing at a greater extent. Good knowledge of network traffic can minimize congestions using information pertaining to road network obtained with the aid of communal callers, pavement detectors, and so on. Using these methods, low featured information is generated with respect to the user in the road network. Although the existing schemes obtain urban traffic information, they fail to calculate the energy drain rate of nodes and to locate equilibrium between the overhead and quality of the routing protocol that renders a great challenge. Thus, an energy-efficient cluster-based vehicle detection in road network using the intention numeration method (CVDRN-IN) is developed. Initially, sensor nodes that detect a vehicle are grouped into separate clusters. Further, we approximate the strength of the node drain rate for a cluster using polynomial regression function. In addition, the total node energy is estimated by taking the integral over the area. Finally, enhanced data aggregation is performed to reduce the amount of data transmission using digital signature tree. The experimental performance is evaluated with Dodgers loop sensor data set from UCI repository and the performance evaluation outperforms existing work on energy consumption, clustering efficiency, and node drain rate.

Simulating the Effects of Drainage and Agriculture on Hydrology and Sediment in the Minnesota River Basin

NASA Astrophysics Data System (ADS)

Downer, C. W.; Pradhan, N. R.; Skahill, B. E.; Banitt, A. M.; Eggers, G.; Pickett, R. E.

2014-12-01

Throughout the Midwest region of the United States, slopes are relatively flat, soils tend to have low permeability, and local water tables are high. In order to make the region suitable for agriculture, farmers have installed extensive networks of ditches to drain off excess surface water and subsurface tiles to lower the water table and remove excess soil water in the root zone that can stress common row crops, such as corn and soybeans. The combination of tiles, ditches, and intensive agricultural land practices radically alters the landscape and hydrology. Within the watershed, tiles have outlets to both the ditch/stream network as well as overland locations, where the tile discharge appears to initiate gullies and exacerbate overland erosion. As part of the Minnesota River Basin Integrated Study we are explicitly simulating the tile and drainage systems in the watershed at multiple scales using the physics-based watershed model GSSHA (Gridded Surface Subsurface Hydrologic Analysis). The tile drainage system is simulated as a network of pipes that collect water from the local water table. Within the watershed, testing of the methods on smaller basins shows the ability of the model to simulate tile flow, however, application at the larger scale is hampered by the computational burden of simulating the flow in the complex tile drain networks that drain the agricultural fields. Modeling indicates the subsurface drains account for approximately 40% of the stream flow in the Seven Mile Creek sub-basin account in the late spring and early summer when the tile is flowing. Preliminary results indicate that agricultural tile drains increase overland erosion in the Seven Mile Creek watershed.

Climatic and Landscape Controls on Storage Capacity of Urban Stormwater Control Measures (SCMs): Implications for Stormwater-Stream Connectivity

NASA Astrophysics Data System (ADS)

Fanelli, R. M.; Prestegaard, K. L.; Palmer, M.

2015-12-01

Urbanization alters watershed hydrological processes; impervious surfaces increase runoff generation, while storm sewer networks increase connectivity between runoff sources and streams. Stormwater control measures (SCMs) that enhance stormwater infiltration have been proposed to mitigate these effects by functioning as stormwater sinks. Regenerative stormwater conveyances structures (RSCs) are an example of infiltration-based SCMs that are placed between storm sewer outfalls and perennial stream networks. Given their location, RSCs act as critical nodes that regulate stormwater-stream connectivity. Therefore, the storage capacity of a RSC structure may exert a major control on the frequency, duration, and magnitude of these connections. This project examined both hydrogeological and hydro-climatic factors that could influence storage capacity of RSC structures. We selected three headwater (5-48 ha) urban watersheds near Annapolis, Maryland, USA. Each watershed is drained by first-order perennial streams and has been implemented with a RSC structure. We conducted high-frequency precipitation and stream stage monitoring below the outlet of each RSC structure for a 1-year period. We also instrumented one of the RSC structures with groundwater wells to monitor changes in subsurface storage over time. Using these data, we 1) identified rainfall thresholds for RSC storage capacity exceedance; 2) quantified the frequency and duration of connectivity when the storage capacity of each RSC was exceeded; and 3) evaluated both event-scale and seasonal changes in groundwater levels within the RSC structure. Precipitation characteristics and antecedent precipitation indices influenced the frequency and duration of stormwater-stream connections. We hypothesize both infiltration limitations and storage limitations of the RSCs contributed to the temporal patterns we observed in stormwater-stream connectivity. We also observed reduced storage potential as contributing area and percent impervious cover increased. Overall, the efficacy of urban SCMs for mitigating the impacts of urbanization and reducing stormwater-stream connectivity is dependent on both climate and the landscape context in which they are placed.

Predicting typhoon-induced storm surge tide with a two-dimensional hydrodynamic model and artificial neural network model

NASA Astrophysics Data System (ADS)

Chen, W.-B.; Liu, W.-C.; Hsu, M.-H.

2012-12-01

Precise predictions of storm surges during typhoon events have the necessity for disaster prevention in coastal seas. This paper explores an artificial neural network (ANN) model, including the back propagation neural network (BPNN) and adaptive neuro-fuzzy inference system (ANFIS) algorithms used to correct poor calculations with a two-dimensional hydrodynamic model in predicting storm surge height during typhoon events. The two-dimensional model has a fine horizontal resolution and considers the interaction between storm surges and astronomical tides, which can be applied for describing the complicated physical properties of storm surges along the east coast of Taiwan. The model is driven by the tidal elevation at the open boundaries using a global ocean tidal model and is forced by the meteorological conditions using a cyclone model. The simulated results of the hydrodynamic model indicate that this model fails to predict storm surge height during the model calibration and verification phases as typhoons approached the east coast of Taiwan. The BPNN model can reproduce the astronomical tide level but fails to modify the prediction of the storm surge tide level. The ANFIS model satisfactorily predicts both the astronomical tide level and the storm surge height during the training and verification phases and exhibits the lowest values of mean absolute error and root-mean-square error compared to the simulated results at the different stations using the hydrodynamic model and the BPNN model. Comparison results showed that the ANFIS techniques could be successfully applied in predicting water levels along the east coastal of Taiwan during typhoon events.

Headwater Nutrient Concentration Patterns in Response to Storm Events Across Land Use Types using In Situ Sensors

NASA Astrophysics Data System (ADS)

Price, A.; Wollheim, W. M.; Mulukutla, G. K.; Carey, R. O.; McDowell, W. H.

2012-12-01

Understanding the aquatic biogeochemical impacts of land use change and climate variability will require improved understanding of nutrient variability over temporal scales ranging from storms to seasons. New in situ sensor technology offers the prospect of efficient nutrient measurements over multiple time scales. We quantified nutrient flux patterns in response to storm events across seasons using in situ nutrient sensors deployed in headwater streams draining three land use types (forest, suburban, and agriculture) within the Lamprey River watershed, New Hampshire, between April-December 2012. We utilized two sensor suites, each consisting of a Satlantic Submersible Ultraviolet Nitrate Analyzer (NO3-N), Turner Designs C6 Multi-Sensor Platform (CDOM, Turbidity, Chl), Hydrolab MS5 (Dissolved Oxygen, pH), WET Labs Cycle P (PO4-P), and Hobo Water Level & Conductivity meters. Preliminary spring/summer comparisons at the suburban site suggest increased baseflow nitrate concentrations and decreased diurnal nitrate variability (~0.05 vs. 0.035 mg/L daily fluctuation) following leaf emergence in spring. Nitrate concentrations were diluted during storms. Hysteresis was evident, suggesting groundwater nitrate sources attributable to septic systems were diluted by surface runoff during spring storms. The agricultural stream showed similar but more extreme patterns of increasing baseflow nitrate during the summer (~2.4 to 4.1 mg/L) and dilution during storms. The compilation of a high-frequency dataset for headwater streams across seasons and land-use types will provide valuable insight into complex land use/water quality relationships in urbanizing watersheds.

Detection of Hail Storms in Radar Imagery Using Deep Learning

NASA Technical Reports Server (NTRS)

Pullman, Melinda; Gurung, Iksha; Ramachandran, Rahul; Maskey, Manil

2017-01-01

In 2016, hail was responsible for 3.5 billion and 23 million dollars in damage to property and crops, respectively, making it the second costliest weather phenomenon in the United States. In an effort to improve hail-prediction techniques and reduce the societal impacts associated with hail storms, we propose a deep learning technique that leverages radar imagery for automatic detection of hail storms. The technique is applied to radar imagery from 2011 to 2016 for the contiguous United States and achieved a precision of 0.848. Hail storms are primarily detected through the visual interpretation of radar imagery (Mrozet al., 2017). With radars providing data every two minutes, the detection of hail storms has become a big data task. As a result, scientists have turned to neural networks that employ computer vision to identify hail-bearing storms (Marzbanet al., 2001). In this study, we propose a deep Convolutional Neural Network (ConvNet) to understand the spatial features and patterns of radar echoes for detecting hailstorms.

Strong convective storm nowcasting using a hybrid approach of convolutional neural network and hidden Markov model

NASA Astrophysics Data System (ADS)

Zhang, Wei; Jiang, Ling; Han, Lei

2018-04-01

Convective storm nowcasting refers to the prediction of the convective weather initiation, development, and decay in a very short term (typically 0 2 h) .Despite marked progress over the past years, severe convective storm nowcasting still remains a challenge. With the boom of machine learning, it has been well applied in various fields, especially convolutional neural network (CNN). In this paper, we build a servere convective weather nowcasting system based on CNN and hidden Markov model (HMM) using reanalysis meteorological data. The goal of convective storm nowcasting is to predict if there is a convective storm in 30min. In this paper, we compress the VDRAS reanalysis data to low-dimensional data by CNN as the observation vector of HMM, then obtain the development trend of strong convective weather in the form of time series. It shows that, our method can extract robust features without any artificial selection of features, and can capture the development trend of strong convective storm.

Precision Monitoring of Water Level in a Salt Marsh with Low Cost Tilt Loggers

NASA Astrophysics Data System (ADS)

Sheremet, Vitalii A.; Mora, Jordan W.

2016-04-01

Several salt pannes and pools in the Sage Lot tidal marsh of Waquoit Bay system, MA were instrumented with newly developed Arm-and-Float water level gauges (utilizing accelerometer tilt logger) permitting to record water level fluctuations with accuracy of 1 mm and submillimeter resolution. The methodology of the instrument calibration, deployment, and elevation control are described. The instrument performance was evaluated. Several month long deployments allowed us to analyze the marsh flooding and draining processes, study differences among the salt pannes. The open channel flow flooding-draining mechanism and slower seepage were distinguished. From the drain curve the seepage rate can be quantified. The seepage rate remains approximately constant for all flooding draining episodes, but varies from panne to panne depending on bottom type and location. Seasonal differences due to the growth of vegetation are also recorded. The analysis of rain events allows us to estimate the catch area of subbasins in the marsh. The implication for marsh ecology and marsh accretion are discussed. The gradual sea level rise coupled with monthly tidal datum variability and storm surges result in migration and development of a salt marsh. The newly developed low cost instrumentation allows us to record and analyze these changes and may provide guidance for the ecological management.

An investigation of the stable isotopes, geochemistry and morphology of major streams in Dominica, Lesser Antilles: 2014 - 2017

NASA Astrophysics Data System (ADS)

Kopas, D. C.; Joseph, E. P.; Frey, H. M.

2017-12-01

The island of Dominica is a recently active (<200 ka) volcanic island located in the Lesser Antilles, with nine potentially active centers. Of the volcanic islands of the Lesser Antilles, it is the most rugged and has one the greatest stream densities (350 over 750 km2) and precipitation rates (up to 10,000 mm/yr in the mountainous interior). Sixty-seven meteoric streams across the island have been sampled annually over the last 4 years. Field measurements including pictures, pH and temperature, were recorded and water samples taken and analyzed for alkalinity, major elements (cations and anions), trace elements and stable isotopes (carbon, deuterium, and oxygen). Variations in water chemistry and river morphology were compared to various parameters, including precipitation, landslide locations, and lithology for each of the catchments. Within the study period, on August 27th, 2015, a significant tropical storm, Erika, made landfall in Dominica, depositing more than 500 mm of rainfall in 10 hours. There was little infiltration of the rainwater (over 50-60% run-off), which resulted in significant landslides, flash floods and damage to infrastructure and loss of life. Despite the obvious morphologic changes to the streams and high discharge during the storm event, preliminary analysis has shown little change in major stream geochemistry following the passage of Tropical Storm Erika. The 10-month time gap between the storm and the post-storm field sampling in June 2016 may be a factor of why geochemical changes were not observed. One of the most significant variations of stream composition during the study period was annual shifts in δD between -1.3 to -5.8 ‰ and δ18O between -1.98 to -2.61 ‰. A possible factor influencing the δ18O of surface waters is seasonal variation in rainfall. The dominant control on precipitation δ18O values is the amount effect, whereby rainfall amount and δ18O are inversely correlated. This relationship is a proxy for changes in δ18O values of surface waters. The data also suggest that hydrothermal fluids are not a prominent contributor to Dominican rivers, despite the presence of active volcanism and numerous hydrothermal systems on the island. The exceptions are the White River, which drains the Valley of Desolation and Boiling Lake and the Lamothe River, which drains the Cold Soufrierre.

Fuzzy neural network for flow estimation in sewer systems during wet weather.

PubMed

Shen, Jun; Shen, Wei; Chang, Jian; Gong, Ning

2006-02-01

Estimation of the water flow from rainfall intensity during storm events is important in hydrology, sewer system control, and environmental protection. The runoff-producing behavior of a sewer system changes from one storm event to another because rainfall loss depends not only on rainfall intensities, but also on the state of the soil and vegetation, the general condition of the climate, and so on. As such, it would be difficult to obtain a precise flowrate estimation without sufficient a priori knowledge of these factors. To establish a model for flow estimation, one can also use statistical methods, such as the neural network STORMNET, software developed at Lyonnaise des Eaux, France, analyzing the relation between rainfall intensity and flowrate data of the known storm events registered in the past for a given sewer system. In this study, the authors propose a fuzzy neural network to estimate the flowrate from rainfall intensity. The fuzzy neural network combines four STORMNETs and fuzzy deduction to better estimate the flowrates. This study's system for flow estimation can be calibrated automatically by using known storm events; no data regarding the physical characteristics of the drainage basins are required. Compared with the neural network STORMNET, this method reduces the mean square error of the flow estimates by approximately 20%. Experimental results are reported herein.

Storm water contamination and its effect on the quality of urban surface waters.

PubMed

Barałkiewicz, Danuta; Chudzińska, Maria; Szpakowska, Barbara; Świerk, Dariusz; Gołdyn, Ryszard; Dondajewska, Renata

2014-10-01

We studied the effect of storm water drained by the sewerage system and discharged into a river and a small reservoir, on the example of five catchments located within the boundaries of the city of Poznań (Poland). These catchments differed both in terms of their surface area and land use (single- and multi-family housing, industrial areas). The aim of the analyses was to explain to what extent pollutants found in storm water runoff from the studied catchments affected the quality of surface waters and whether it threatened the aquatic organisms. Only some of the 14 studied variables and 22 chemical elements were important for the water quality of the river, i.e., pH, TSS, rain intensity, temperature, conductivity, dissolved oxygen, organic matter content, Al, Cu, Pb, Zn, Fe, Cd, Ni, Se, and Tl. The most serious threat to biota in the receiver came from the copper contamination of storm water runoff. Of all samples below the sewerage outflow, 74% exceeded the mean acute value for Daphnia species. Some of them exceeded safe concentrations for other aquatic organisms. Only the outlet from the industrial area with the highest impervious surface had a substantial influence on the water quality of the river. A reservoir situated in the river course had an important influence on the elimination of storm water pollution, despite the very short residence time of its water.

Biogeochemical responses of arctic hillslopes to storms and seasonal thaw

NASA Astrophysics Data System (ADS)

Harms, T.

2015-12-01

Resilience of watersheds includes maintenance of biogeochemical functions, including retention and transport of solutes, following perturbations. In the arctic, important perturbations that may result in departure from the current state of watersheds include gradual or catastrophic loss of permafrost, increasing temperature, and increased intensity of storms. However, these long-term changes are occurring against the backdrop of variation introduced by seasonality and storms. Thus, establishing baselines that capture temporal patterns is an essential step in predicting vulnerability of arctic watersheds to climate-induced change. We have documented temporal patterns in solute concentrations of six water tracks, zero-order channels that drain arctic hillslopes. Temporal patterns were typically site-specific, underscoring the value of watershed monitoring for predicting responses to perturbations. In some catchments, peak export of organic carbon, nitrogen, and phosphorus occurred during snowmelt, whereas in others, flushing during storms yielded greater export. Concentrations of non-limiting inorganic solutes (e.g., sulfate, calcium) increased through the thaw period in some catchments, suggesting that these solutes may serve as indicators of degrading permafrost. We observed a decrease in the magnitude of flushing of biolabile solutes (e.g., ammonium, organic carbon) during storms through the thaw season, reflecting hydrologic disconnection of upper, organic soils as thaw depth increases and flowpaths deepen. The observed patterns establish a template of temporal variation against which future observations may be assessed to evaluate departures from a stable state.

On the watch for geomagnetic storms

USGS Publications Warehouse

Green, Arthur W.; Brown, William M.

1997-01-01

Geomagnetic storms, induced by solar activity, pose significant hazards to satellites, electrical power distribution systems, radio communications, navigation, and geophysical surveys. Strong storms can expose astronauts and crews of high-flying aircraft to dangerous levels of radiation. Economic losses from recent geomagnetic storms have run into hundreds of millions of dollars. With the U.S. Geological Survey (USGS) as the lead agency, an international network of geomagnetic observatories monitors the onset of solar-induced storms and gives warnings that help diminish losses to military and commercial operations and facilities.

A statistical model of extreme storm rainfall

NASA Astrophysics Data System (ADS)

Smith, James A.; Karr, Alan F.

1990-02-01

A model of storm rainfall is developed for the central Appalachian region of the United States. The model represents the temporal occurrence of major storms and, for a given storm, the spatial distribution of storm rainfall. Spatial inhomogeneities of storm rainfall and temporal inhomogeneities of the storm occurrence process are explicitly represented. The model is used for estimating recurrence intervals of extreme storms. The parameter estimation procedure developed for the model is based on the substitution principle (method of moments) and requires data from a network of rain gages. The model is applied to a 5000 mi2 (12,950 km2) region in the Valley and Ridge Province of Virginia and West Virginia.

Thermal Fluxes and Temperatures in Small Urban Headwater Streams of the BES LTER: Landscape Forest and Impervious Patches and the Importance of Spatial and Temporal Scales

NASA Astrophysics Data System (ADS)

Kim, H.; Belt, K. T.; Welty, C.; Heisler, G.; Pouyat, R. V.; McGuire, M. P.; Stack, W. P.

2006-05-01

Water and material fluxes from urban landscape patches to small streams are modulated by extensive "engineered" drainage networks. Small urban headwater catchments are different in character and function from their larger receiving streams because of their extensive, direct connections to impervious surface cover (ISC) and their sometimes buried nature. They need to be studied as unique functional hydrologic units if impacts on biota are to be fully understood. As part of the Baltimore Ecosystem Study LTER project, continuous water temperature data are being collected at 2-minute intervals at over twenty small catchments representing various mixtures of forest and ISC. Suburban stream sites with greater ISC generally have higher summer water temperatures. Suburban catchments with most of their channel drainage contained within storm drain pipes show subdued diurnal variation and cool temperatures, but with very large spikes in summer runoff events. Conversely, high ISC urban piped streams have elevated "baseline" temperatures that stand well above all the other monitoring sites. There is a pronounced upstream-downstream effect; nested small headwater catchments experience more frequent, larger temperature spikes related to runoff events than downstream sites. Also, runoff-initiated temperature elevations at small stream sites unexpectedly last much longer than the storm runoff hydrographs. These observations suggest that for small headwater catchments, urban landscapes not only induce an ambient, "heat island" effect on stream temperatures, but also introduce thermal disturbance regimes and fluxes that are not trivial to aquatic biota.

A field effect glucose sensor with a nanostructured amorphous In-Ga-Zn-O network.

PubMed

Du, Xiaosong; Li, Yajuan; Herman, Gregory S

2016-11-03

Amorphous indium gallium zinc oxide (IGZO) field effect transistors (FETs) are a promising technology for a wide range of electronic applications. Herein, we fabricated and characterized FETs with a nanostructured IGZO network as a sensing transducer. The IGZO was patterned using colloidal lithography and electrohydrodynamic printing, where an 8 μm wide nanostructured close-packed hexagonal IGZO network was obtained. Electrical characterization of the nanostructured IGZO network FET demonstrated a drain-source current on-off ratio of 6.1 × 10 3 and effective electron mobilities of 3.6 cm 2 V -1 s -1 . The nanostructured IGZO network was functionalized by aminosilane groups with cross-linked glucose oxidase. The devices demonstrated a decrease in drain-source conductance and a more positive V ON with increasing glucose concentration. These changes are ascribed to the acceptor-like surface states associated with positively charged aminosilane groups attached to the nanostructured IGZO surface. Continuous monitoring of the drain-source current indicates a stepwise and fully reversible response to glucose concentrations with a short response time. The specific catalytic reaction between the GOx enzyme and glucose eliminates interference from acetaminophen/ascorbic acid. We demonstrate that nanostructured IGZO FETs have improved sensitivity compared to non-nanostructured IGZO for sensing glucose and can be potentially extended to other biosensor technologies.

Modeling ionospheric foF 2 response during geomagnetic storms using neural network and linear regression techniques

NASA Astrophysics Data System (ADS)

Tshisaphungo, Mpho; Habarulema, John Bosco; McKinnell, Lee-Anne

2018-06-01

In this paper, the modeling of the ionospheric foF 2 changes during geomagnetic storms by means of neural network (NN) and linear regression (LR) techniques is presented. The results will lead to a valuable tool to model the complex ionospheric changes during disturbed days in an operational space weather monitoring and forecasting environment. The storm-time foF 2 data during 1996-2014 from Grahamstown (33.3°S, 26.5°E), South Africa ionosonde station was used in modeling. In this paper, six storms were reserved to validate the models and hence not used in the modeling process. We found that the performance of both NN and LR models is comparable during selected storms which fell within the data period (1996-2014) used in modeling. However, when validated on storm periods beyond 1996-2014, the NN model gives a better performance (R = 0.62) compared to LR model (R = 0.56) for a storm that reached a minimum Dst index of -155 nT during 19-23 December 2015. We also found that both NN and LR models are capable of capturing the ionospheric foF 2 responses during two great geomagnetic storms (28 October-1 November 2003 and 6-12 November 2004) which have been demonstrated to be difficult storms to model in previous studies.

Verifiable metamodels for nitrate losses to drains and groundwater in the corn belt, USA

USDA-ARS?s Scientific Manuscript database

Metamodels (MMs) consisting of artificial neural networks were developed to simplify and upscale mechanistic fate and transport models for prediction of nitrate losses to drains and groundwater in the Corn Belt, USA. The two final MMs predicted nitrate concentration and flux, respectively, in the sh...

Department of the Navy. FY 1994/FY 1995 Biennial Budget Estimates. Military Construction Program. FY 1994

DTIC Science & Technology

1992-01-01

3 are severely deteriorated. The concrete deck and supporting wood -pile structure are nearing the end of their life cycle. Both piers are to be...PROPOSED CONSTRUCTION One-story building with concrete foundation walls, load bearing masonry walls, and concrete floors; roof with wood truss framing...concrete building addition; concrete foundation and slab on grade; wood truss roof; 750 KVA. 3 phase transformer; utilities; concrete and storm drain. 11

Development and evaluation of a culture-independent method for source determination of fecal wastes in surface and storm waters using reverse transcriptase-PCR detection of FRNA coliphage genogroup gene sequences.

PubMed

Paar, Jack; Doolittle, Mark M; Varma, Manju; Siefring, Shawn; Oshima, Kevin; Haugland, Richard A

2015-05-01

A method, incorporating recently improved reverse transcriptase-PCR primer/probe assays and including controls for detecting interferences in RNA recovery and analysis, was developed for the direct, culture-independent detection of genetic markers from FRNA coliphage genogroups I, II & IV in water samples. Results were obtained from an initial evaluation of the performance of this method in analyses of waste water, ambient surface water and stormwater drain and outfall samples from predominantly urban locations. The evaluation also included a comparison of the occurrence of the FRNA genetic markers with genetic markers from general and human-related bacterial fecal indicators determined by current or pending EPA-validated qPCR methods. Strong associations were observed between the occurrence of the putatively human related FRNA genogroup II marker and the densities of the bacterial markers in the stormwater drain and outfall samples. However fewer samples were positive for FRNA coliphage compared to either the general bacterial fecal indicator or the human-related bacterial fecal indicator markers particularly for ambient water samples. Together, these methods show promise as complementary tools for the identification of contaminated storm water drainage systems as well as the determination of human and non-human sources of contamination. Published by Elsevier B.V.

Discovery of Cyanuric Acid During an Assessment of Natural Organic Matter in Stormflow Water of the Santa Ana River, Southern California, 2003-2004

USGS Publications Warehouse

Leenheer, Jerry A.; Izbicki, John A.; Rostad, Colleen E.; Noyes, Ted I.; Woodside, Greg

2007-01-01

A stormflow study of natural organic matter and organic contaminants in the Santa Ana River, the Mill Creek tributary, and an urban drain tributary discovered cyanuric acid in variable concentrations up to 510 ?g/L. Cyanuric acid was isolated with a hydrophilic natural organic matter (NOM) fraction, and its identity was confirmed by a combination of infrared spectrometry, 13C-nuclear magnetic resonance (13C-NMR) spectrometry, and electrospray ionization/mass spectrometry. Cyanuric acid concentrations, based upon 13C-NMR spectral quantitation, increased during the peak and recessional flows of the storm hydrographs during three storms at three sites. The greatest fluxes of cyanuric acid were observed in the Santa Ana River during the third storm. The most likely source of cyanuric acid is as a metabolite of triazine herbicides, based on hydrographs, land uses of the drainage basins, and the yearly application rates of triazine herbicides. The daily flux of cyanuric acid in Santa Ana River stormflow during the third storm was calculated to be about 1 percent of the yearly application rate for triazine herbicides. Cyanuric acid was not detected in ground water at wells adjacent to the Santa Ana River.

Simulation of quantity and quality of storm runoff for urban catchments in Fresno, California

USGS Publications Warehouse

Guay, J.R.; Smith, P.E.

1988-01-01

Rainfall-runoff models were developed for a multiple-dwelling residential catchment (2 applications), a single-dwelling residential catchment, and a commercial catchment in Fresno, California, using the U.S. Geological Survey Distributed Routing Rainfall-Runoff Model (DR3M-II). A runoff-quality model also was developed at the commercial catchment using the Survey 's Multiple-Event Urban Runoff Quality model (DR3M-qual). The purpose of this study was: (1) to demonstrate the capabilites of the two models for use in designing storm drains, estimating the frequency of storm runoff loads, and evaluating the effectiveness of street sweeping on an urban drainage catchment; and (2) to determine the simulation accuracies of these models. Simulation errors of the two models were summarized as the median absolute deviation in percent (mad) between measured and simulated values. Calibration and verification mad errors for runoff volumes and peak discharges ranged from 14 to 20%. The estimated annual storm-runoff loads, in pounds/acre of effective impervious area, that could occur once every hundred years at the commercial catchment was 95 for dissolved solids, 1.6 for the dissolved nitrite plus nitrate, 0.31 for total recoverable lead, and 120 for suspended sediment. Calibration and verification mad errors for the above constituents ranged from 11 to 54%. (USGS)

Influence of land use on the quantity and quality of runoff along Israel's coastal strip

NASA Astrophysics Data System (ADS)

Goldshleger, Naftaly; Asaf, Lior; Maor, Alon; Garzuzi, Jamil Jamil

2013-04-01

This study presents an analysis of the quantity and quality of urban runoff from various land uses by remote-sensing and GIS technology coupled with hydrological and chemical monitoring. The study areas were located in the cities of Herzliya and Ra'anana, in Israel's coastal plain, where extensive urbanization has taken place over the last 30 years. Land uses in urban basins were analyzed; rain and runoff were measured and sampled at measurement stations representing different land uses (residential, industrial, commercial, roads, gas station). The aim was to analyze land uses by different remote-sensing and GIS techniques, to evaluate the quality and quantity of urban storm water from various land uses, and to verify a method for predicting the impact of urban land uses on quantity and quality of urban storm water. The quality of urban storm water from residential areas was generally very high, and the water is suitable for reuse or direct recharge into the local aquifer. In light of the serious state of the Israeli water sector and the large amounts of unused runoff produced by Israel's cities, together with the high quality of urban storm water drained from the residential areas, it is important to exploit this water source

Probabilistic estimation of dune retreat on the Gold Coast, Australia

USGS Publications Warehouse

Palmsten, Margaret L.; Splinter, Kristen D.; Plant, Nathaniel G.; Stockdon, Hilary F.

2014-01-01

Sand dunes are an important natural buffer between storm impacts and development backing the beach on the Gold Coast of Queensland, Australia. The ability to forecast dune erosion at a prediction horizon of days to a week would allow efficient and timely response to dune erosion in this highly populated area. Towards this goal, we modified an existing probabilistic dune erosion model for use on the Gold Coast. The original model was trained using observations of dune response from Hurricane Ivan on Santa Rosa Island, Florida, USA (Plant and Stockdon 2012. Probabilistic prediction of barrier-island response to hurricanes, Journal of Geophysical Research, 117(F3), F03015). The model relates dune position change to pre-storm dune elevations, dune widths, and beach widths, along with storm surge and run-up using a Bayesian network. The Bayesian approach captures the uncertainty of inputs and predictions through the conditional probabilities between variables. Three versions of the barrier island response Bayesian network were tested for use on the Gold Coast. One network has the same structure as the original and was trained with the Santa Rosa Island data. The second network has a modified design and was trained using only pre- and post-storm data from 1988-2009 for the Gold Coast. The third version of the network has the same design as the second version of the network and was trained with the combined data from the Gold Coast and Santa Rosa Island. The two networks modified for use on the Gold Coast hindcast dune retreat with equal accuracy. Both networks explained 60% of the observed dune retreat variance, which is comparable to the skill observed by Plant and Stockdon (2012) in the initial Bayesian network application at Santa Rosa Island. The new networks improved predictions relative to application of the original network on the Gold Coast. Dune width was the most important morphologic variable in hindcasting dune retreat, while hydrodynamic variables, surge and run-up elevation, were also important

A deep belief network approach using VDRAS data for nowcasting

NASA Astrophysics Data System (ADS)

Han, Lei; Dai, Jie; Zhang, Wei; Zhang, Changjiang; Feng, Hanlei

2018-04-01

Nowcasting or very short-term forecasting convective storms is still a challenging problem due to the high nonlinearity and insufficient observation of convective weather. As the understanding of the physical mechanism of convective weather is also insufficient, the numerical weather model cannot predict convective storms well. Machine learning approaches provide a potential way to nowcast convective storms using various meteorological data. In this study, a deep belief network (DBN) is proposed to nowcast convective storms using the real-time re-analysis meteorological data. The nowcasting problem is formulated as a classification problem. The 3D meteorological variables are fed directly to the DBN with dimension of input layer 6*6*80. Three hidden layers are used in the DBN and the dimension of output layer is two. A box-moving method is presented to provide the input features containing the temporal and spatial information. The results show that the DNB can generate reasonable prediction results of the movement and growth of convective storms.

A Comparison of Cloud-to-Ground Lightning Characteristics and Observations from Multiple Networks and Videos during the 31 May 2013 El Reno, OK Tornadic Supercell Storm

NASA Astrophysics Data System (ADS)

Kuhlman, K. M.; Coy, J.; Seimon, A.

2015-12-01

Cloud-to-ground (CG) lightning flashes recorded by both the National Lightning Detection Network (NLDN) and Earth Networks Total Lightning Network (ENTLN) are compared with three-dimensional lightning mapping observations from the Oklahoma Lightning Mapping Array (OKLMA) and storm chaser video recorded of the 31 May 2013 El Reno tornadic supercell. The El Reno Survey Project (El-Reno-Survey.net) was created to crowd-source the abundance of storm chaser video from this event and provide open-access to the scientific community of the data. An initial comparison of CG lightning flashes captured on these videos with CG data from NLDN revealed a disagreement on the total number of flashes, with NLDN recording many negative CG flashes at lower peak amplitude not apparent in any of the videos. For this study, the area of the comparison was expanded to include the entire storm and data from both the ENTLN and LMA were added to compare the observations from each network in terms of timestamp, location detection, peak current, and polarity of each flash in the period 2230-2330 UTC. An initial comparison of 557 matched NLDN and ENLTN CG flashes, indicated predominately negative polairy CG flashes (58% NLDN/77% ENI) throughout the storm during this period. However, after a 15 kA peak current filter was applied, the NLDN indicated primarily positive polarity (84% +CG) while ENTLN still indicated primarily negative polarity (77% -CG) for the 264 remaining matched flashes. Before the filter was applied, the average distance between the two networks for the same flash was more than 2 km, but improved to approximately 1 km after the 15 kA filter was applied, likely removing some misidentified cloud flashes of uncertain location. This misclassification of IC flashes as CG at low peak current amplitudes for both networks is further evident when compared to video and the OKLMA data. Additionally, the charge analysis of OKLMA flashes revealed the NLDN-determined positive-polarity as correct every time the NLDN and ENTLN disagreed. For the 2013 El Reno supercell storm, there appears to be a major flaw in the ENTLN's ability to determine the polarity of CG flashes despite having roughly similar peak current magnitudes and location for most CG flash occurrences as the NLDN.

Mapping Hurricane Inland-Storm Tides

NASA Astrophysics Data System (ADS)

Turco, M.; East, J. W.; Dorsey, M. E.; McGee, B. D.; McCallum, B. E.; Pearman, J. L.; Sallenger, A. H.; Holmes, R. R.; Berembrock, C. E.; Turnipseed, D. P.; Mason, R. R.

2008-12-01

Historically, hurricane-induced storm-tides were documented through analysis of structural or vegetative damage and high-water marks. However, these sources rarely provided quantitative information about the timing of the flooding, the sequencing of multiple paths by which the storm-surge waters arrived, or the magnitude of waves and wave run-up comprising floodwaters. In response to these deficiencies, the U.S. Geological Survey (USGS) developed and deployed an experimental mobile storm-surge network to provide detailed time-series data for selected hurricane landfalls. The USGS first deployed the network in September 2005 as Hurricane Rita approached the Texas and Louisiana coasts. The network for Rita consisted of 32 water-level and 14 barometric-pressure monitoring sites. Sensors were located at distances ranging from a few hundred feet to approximately 30 miles inland and sampled 4,000 square miles. Deployments have also occurred for Hurricanes Wilma, Gustav, and Ike. For Hurricane Gustav, more than 100 water level sensors were deployed. Analysis of the water-level data enable construction of maps depicting surge topography through time and space, essentially rendering elements of a 3-dimensional view of the storm-surge dome as it moves on- shore, as well as a map of maximum water-level elevations. The USGS also acquired LIDAR topographic data from coasts impacted by hurricanes. These data reveal extreme changes to the beaches and barrier islands that arise from hurricane storm surge and waves. By better understanding where extreme changes occur along our coasts, we will be able to position coastal structures away from hazards.

Shifting Pacific storm tracks as stressors to ecosystems of western North America.

PubMed

Dannenberg, Matthew P; Wise, Erika K

2017-11-01

Much of the precipitation delivered to western North America arrives during the cool season via midlatitude Pacific storm tracks, which may experience future shifts in response to climate change. Here, we assess the sensitivity of the hydroclimate and ecosystems of western North America to the latitudinal position of cool-season Pacific storm tracks. We calculated correlations between storm track variability and three hydroclimatic variables: gridded cool-season standardized precipitation-evapotranspiration index, April snow water equivalent, and water year streamflow from a network of USGS stream gauges. To assess how historical storm track variability affected ecosystem processes, we derived forest growth estimates from a large network of tree-ring widths and land surface phenology and wildfire estimates from remote sensing. From 1980 to 2014, cool-season storm tracks entered western North America between approximately 41°N and 53°N. Cool-season moisture supply and snowpack responded strongly to storm track position, with positive correlations to storm track latitude in eastern Alaska and northwestern Canada but negative correlations in the northwestern U.S. Ecosystems of the western United States were greener and more productive following winters with south-shifted storm tracks, while Canadian ecosystems were greener in years when the cool-season storm track was shifted to the north. On average, larger areas of the northwestern United States were burned by moderate to high severity wildfires when storm tracks were displaced north, and the average burn area per fire also tended to be higher in years with north-shifted storm tracks. These results suggest that projected shifts of Pacific storm tracks over the 21st century would likely alter hydroclimatic and ecological regimes in western North America, particularly in the northwestern United States, where moisture supply and ecosystem processes are highly sensitive to the position of cool-season storm tracks. © 2017 John Wiley & Sons Ltd.

Modeling Subsurface Storm and Tile Drain Systems in GSSHA with SUPERLINK

DTIC Science & Technology

2014-09-01

side is computed as . ( )e Kq d m m L   2 0 01 2 (7) de is defined as ( van der Molen and Wesseling (1991)) ERDC/CHL TR-14-11 15...Conservation Service. Van der Molen , W.H., and J. Wesseling. 1991. A solution in closed form and a series solution to replace the tables for thickness of...effective lateral hydraulic conductivity (cm hr-1) C = 1 in the present version. Hooghoudt ( van Schilfgaarde 1974) characterized flow to cylindrical

Comparison of direct outflow calculated by modified SCS-CN methods for mountainous and highland catchments in upper Vistula Basin, Poland and lowland catchment in South Carolina, U.S.A

Treesearch

A. Walega; A. Cupak; D.M. Amatya; E. Drozdzal

2017-01-01

The aim of the study is to compare direct outflow from storm events estimated using modifications of original SCS-CN procedure. The study was conducted in a mountainous catchment of Kamienica River and a highland catchment draining Stobnica River located in Upper Vistula water region, both in Poland, and a headwater lowland watershed WS80 located at the Santee...

Characterizing subsurface water flow to artificial drain lines using fiber-optic distributed temperature sensing

NASA Astrophysics Data System (ADS)

Shults, D.; Brooks, E. S.; Heinse, R.; Keller, C. K.

2017-12-01

Over the last several years growers have experienced increasingly wet spring conditions in the Palouse Region located in North Idaho, Eastern Washington and Eastern Oregon. As a result more artificial drain lines are being installed so growers can access their fields earlier in the growing season. Additionally there has been increasing adoption of no-tillage practices among growers in order minimize erosion and runoff in the region. There is a growing body of evidence that suggests long-term no-tillage may lead to the establishment of large macropore networks through increased earthworm activity and the preservation of root channels. These macropore networks, in conjunctions with the presence of artificial drains lines, may create connected preferential flow paths from agricultural fields to receiving streams. This connectivity of flow paths from agricultural fields to receiving water bodies may increase the loading of nutrients and agricultural chemicals as some flow paths may largely bypass soil matrix interaction where materials can be sequestered. Our primary objective for this study was to characterize subsurface flow to two artificial drain lines, one under conventional tillage and the other under no-tillage, using distributed temperature sensing (DTS) technology. During the study (November 2016-April 2017) the near surface soil-water temperature was consistently colder than that of deeper depths. Temperature was thus used as a tracer as snow melt and soil-water moved from the near surface to the drain lines during snowmelt and precipitation events. The spatial and temporal variability of the temperature along the artificial drain line under no-tillage practices was found to be greater than that of the conventional tilled field. It is hypothesized that preferential flow paths are responsible for the increased variability of temperature seen in the drain line under long term no-till management. The temperature along the conventional till drain line showed a dampened response to snow melt and precipitation events during the winter indicating matrix flow was the predominate flow mechanism. In addition to temperature traces, water chemistry (electrical conductivity, pH and nitrate) and discharge measurements were collected at the outlet of each drain line as well as at access ports along the drain lines.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Eugene; Pierce, Julia; Mahat, Vinod

This project is a part of the Regional Resiliency Assessment Program, led by the Department of Homeland Security, to address flooding hazards of regional significance for Portland, Maine. The pilot study was performed by Argonne National Laboratory to identify differences in spatial rainfall distributions between the radar-derived and rain-gauge rainfall datasets and to evaluate their impacts on urban flooding. The flooding impact analysis utilized a high-resolution 2-dimensional (2-D) hydrodynamic model (15 ft by 15 ft) incorporating the buildings, streets, stream channels, hydraulic structures, an existing city storm drain system, and assuming a storm surge along the coast coincident with amore » heavy rainfall event. Two historical storm events from April 16, 2007, and September 29, 2015, were selected for evaluation. The radar-derived rainfall data at a 200-m resolution provide spatially-varied rainfall patterns with a wide range of intensities for each event. The resultant maximum flood depth using data from a single rain gauge within the study area could be off (either under- or over-estimated) by more than 10% in the 2007 storm and more than 60% in the 2015 storm compared to the radar-derived rainfall data. The model results also suggest that the inundation area with a flow depth at or greater than 0.5 ft could reach 11% (2007 storm) and 17% (2015 storm) of the total study area, respectively. The lowland areas within the neighborhoods of North Deering, East Deering, East and West Baysides and northeastern Parkside, appear to be more vulnerable to the flood hazard in both storm events. The high-resolution 2-D hydrodynamic model with high-resolution radar-derived rainfall data provides an excellent tool for detailed urban flood analysis and vulnerability assessment. The model developed in this study could be potentially used to evaluate any proposed mitigation measures and optimize their effects in the future for Portland, ME.« less

A GIS and Remote Sensing Perspective on the Hydrodynamic Response of the 2014 Kashmir Floods

NASA Astrophysics Data System (ADS)

Tyagi, H.; Goyal, A.

2016-12-01

In September-2014, the Jammu and Kashmir state of India received unprecedented rains due to strong interaction of the western disturbances with the retreating monsoon. Consequently, several districts were ravaged by the catastrophic floods and subsequent landslides. On 5th September-2014, the Jhelum River in Srinagar breached the danger level by over 1.34 m. The flood discharge was also recorded to be around 2.8 times the normal discharge. The current study examined the hydrodynamic response of the catchment to this rainstorm event. Moreover, the flood progression and recession was analyzed from the remote sensing imageries in pre-flood and post-flood scenarios. Also, the spatio-temporal extent of the inundated and inundation prone areas was mapped using GIS. It was concluded that the deluge was triggered by record rainfall coupled with choked stormwater drains, and reduced carrying capacity of the channel due to excessive silt, encroached floodplains and unplanned urbanization. Past research on the present study area has reported shrinkage and degradation of wetlands and water bodies due to sedimentation and deforestation. Further, even when this region is susceptible to flashfloods historically, and the meteorology data hints towards increasing trend in temperature and rainfall, there is no flood forecasting station in this state. Understandably, it is incumbent on the government to plan for such natural calamities and their consequences. Thus, it is the need of the hour to rehabilitate the water bodies and storm drains, and build a robust network of hydro-meteorology stations. Also, it becomes imperative to scientifically demarcate the river margins as they not only come handy in groundwater recharge, natural silting-desilting and flood mitigation during annual cycles of lows flows and floods, but also support a delicate ecological balance being a medium of land-water interface.

Radar and Atmospheric Sounding observations around 23 TGFs

NASA Astrophysics Data System (ADS)

Chronis, T.; Briggs, M. S.; Priftis, G.

2014-12-01

This study employs 23 Terrestrial Gamma-ray Flashes (TGF) detected with NASA's Fermi Gamma-ray Burst Monitor (GBM) and collocated with the World Wide Lightning Location Network and the Earth Networks Total Lightning Network with 9 WSR-88D (NEXRAD) located in Brownsville and Corpus Christy (Texas), Lake Charles (Louisiana), Key West, Miami, Tampa and Eglin Air Force Base (Florida), San Juan (Puerto Rico) and Andersen Air Force Base (Guam). The NEXRAD Enhanced Echo Tops (EET) and Vertical Integrated Liquid Density (VILD) are traditional proxies to storm height and severity. To retrieve the storm characteristics we construct probability histograms of respective EET and VILD values around each TGF.Here we show that although high-topped storms are consistently present in the vicinity of TGFs, the VILD values indicate storms of disparate convective strengths. In particular, the majority of our TGF sample is encompassed by storms of high EET (>10-11 km) values and in their majority overall VILD < ~2.0 gr m-3.These EET and VILD values are common in summertime oceanic/coastal low-latitude thunderstorms where the main convective core is limited in the first few kilometres and the updrafts are weak and narrow. Qualitative observations from the temporal evolution of the volumetric radar reflectivity shows that in a few cases the TGF emission signals the dissipation stage of the main convective core, although this suggestion is tentative and requires more sophisticated and currently ongoing storm tracking techniques. The atmospheric soundings (where available in spatial and temporal proximity with the respective TGF) indicate that TGF producing storms can exhibit a significant variation in their respective thermodynamic environment and type (e.g. regular to high CAPE, pulse vs. high shear etc). The authors acknowledge the valuable contributions of the GBM Team, Bob Holtzworth (WWLLN) and Stan Heckman (ENTLN).

Characterization of water quality in selected tributaries of the Alamosa River, southwestern Colorado, including comparisons to instream water-quality standards and toxicological reference values, 1995-97

USGS Publications Warehouse

Ortiz, Roderick F.; Ferguson, Sheryl A.

2001-01-01

A comprehensive water-quality sampling network was implemented by the U.S. Geological Survey from 1995 through 1997 at 12 tributary sites to the Alamosa River. The network was designed to address data gaps identified in the initial ecological risk assessment of the Summitville Superfund site. Tributaries draining hydrothermally altered areas had higher median values for nearly all measured properties and constituents than tributaries draining unaltered areas. Colorado instream standards for pH, copper, iron, and zinc were in attainment at most tributary sites. Instream standards for pH and chronic aquatic-life standards for iron were not attained in Jasper Creek. Toxicological reference values were most often exceeded at Iron Creek, Alum Creek, Bitter Creek, Wightman Fork, and Burnt Creek. These tributaries all drain hydrothermally altered areas.

A High Density Storm Surge Monitoring Network: Evaluating the Ability of Wetland Vegetation to Reduce Storm Surge

NASA Astrophysics Data System (ADS)

Lawler, S.; Denton, M.; Ferreira, C.

2013-12-01

Recent tropical storm activity in the Chesapeake Bay and a potential increase in the predicted frequency and magnitude of weather systems have drawn increased attention to the need for improved tools for monitoring, modeling and predicting the magnitude of storm surge, coastal flooding and the respective damage to infrastructure and wetland ecosystems. Among other forms of flood protection, it is believed that coastal wetlands and vegetation can act as a natural barrier that slows hurricane flooding, helping to reduce the impact of storm surge. However, quantifying the relationship between the physical process of storm surge and its attenuation by wetland vegetation is an active area of research and the deployment of in-situ measuring devices is crucial to data collection efforts in this field. The United States Geological Survey (USGS) mobile storm-surge network has already successfully provided a framework for evaluating hurricane induced storm surge water levels on a regional scale through the use of in-situ devices installed in areas affected by storm surge during extreme events. Based on the success of the USGS efforts, in this study we adapted the monitoring network to cover relatively small areas of wetlands and coastal vegetation with an increased density of sensors. Groups of 6 to 10 water level sensors were installed in sites strategically selected in three locations on the Virginia coast of the lower Chesapeake Bay area to monitor different types of vegetation and the resulting hydrodynamic patterns (open coast and inland waters). Each group of sensors recorded time series data of water levels for both astronomical tide circulation and meteorological induced surge. Field campaigns were carried out to survey characteristics of vegetation contributing to flow resistance (i.e. height, diameter and stem density) and mapped using high precision GPS. A geodatabase containing data from field campaigns will support the development and calibration of computational models to simulate storm surge flow over wetlands specifically designed to represent Virginia's aquatic vegetation and to improve our fundamental knowledge of tide and storm surge hydrodynamics in estuarine wetlands. This poster will present the results of the field measurements for events during the 2013 Hurricane Season, tidal flows within the study areas, and surge attenuation rates according to vegetation characteristics.

Global Ionosphere Perturbations Monitored by the Worldwide GPS Network

NASA Technical Reports Server (NTRS)

Ho, C. M.; Manucci, A. T.; Lindqwister, U. J.; Pi, X.

1996-01-01

For the first time, measurements from the Global Positioning System (GPS) worldwide network are employed to study the global ionospheric total electron content(TEC) changes during a magnetic storm (November 26, 1994). These measurements are obtained from more than 60 world-wide GPS stations which continuously receive dual-frequency signals. Based on the delays of the signals, we have generated high resolution global ionospheric maps (GIM) of TEC at 15 minute intervals. Using a differential method comparing storm time maps with quiet time maps, we find that significant TEC increases (the positive effect ) are the major feature in the winter hemisphere during this storm (the maximum percent change relative to quiet times is about 150 percent).

Temporal Changes in Photochemically Labile DOM and Implications for Carbon Budgets in Peatland Aquatic Systems

NASA Astrophysics Data System (ADS)

Pickard, A.

2015-12-01

Aquatic systems in peatland catchments are subject to high loading of dissolved organic matter (DOM) from surrounding terrestrial environments. However the significance of photochemical transformation of DOM in peatland carbon budgets remains poorly constrained. In this study UV irradiation experiments were conducted on water samples collected over one year from two contrasting systems in Scotland: a stream draining a peatland with high levels of DOM and a reservoir draining a peat catchment with low levels of DOM. Further samples were collected from the high DOM system during two storm events. After experimental exposure, optical and chemical analyses were employed to determine photochemical lability of the DOM pool. At both sites irradiation-induced decreases in dissolved organic carbon (DOC) as a percentage of the total carbon pool were greatest in winter, suggesting that DOM was depleted in photo-reactive molecules in summer. Seasonal variability in DOC was high at the stream site and was positively correlated with CO₂ and CO photoproduction (r2 = 0.81 and 0.83, respectively; p<0.05). Lignin phenol analyses indicate considerable contribution of peat to the DOM pool at the stream site, particularly during summer. Whilst DOC concentrations did not vary greatly during storm events, UV-Vis absorbance indicators did, signifying changing DOM source material from activation of different hydrological pathways. The most photo-reactive DOM occurred 5-10 hours after peak discharge, suggesting that storms replenish photochemically labile DOM in headwater streams. Conservative estimates using data from this study suggest that up to 7% of the DOM pool of peatland streams can be lost (primarily as CO₂ and CO) upon exposure to 8 hours of environmentally representative UV irradiation. Further investigation in field campaigns under natural UV exposure are underway to assess the importance of photodegradation of DOM as a loss pathway of carbon based gases from aquatic systems.

Fecal-indicator bacteria in streams alonga gradient of residential development

USGS Publications Warehouse

Frenzel, Steven A.; Couvillion, Charles S.

2002-01-01

Fecal-indicator bacteria were sampled at 14 stream sites in Anchorage, Alaska, USA, as part of a study to determine the effects of urbanization on water quality. Population density in the subbasins sampled ranged from zero to 1,750 persons per square kilometer. Higher concentrations of fecal-coliform, E. coli, and enterococci bacteria were measured at the most urbanized sites. Although fecal-indicator bacteria concentrations were higher in summer than in winter, seasonal differences in bacteria concentrations generally were not significant. Areas served by sewer systems had significantly higher fecal-indicator bacteria concentrations than did areas served by septic systems. The areas served by sewer systems also had storm drains that discharged directly to the streams, whereas storm sewers were not present in the areas served by septic systems. Fecal-indicator bacteria concentrations were highly variable over a two-day period of stable streamflow, which may have implications for testing of compliance to water-quality standards.

Vulnerability of fuel distribution systems to hazards in coastal communities : final research report.

DOT National Transportation Integrated Search

2017-04-30

Coastal communities are vulnerable to disruptions in their fuel distribution networks due to : tropical storms, hurricanes and associated flooding. These disruptions impact communities by : limiting fueling in the days following the storm potentially...

The Potential Observation Network Design with Mesoscale Ensemble Sensitivities in Complex Terrain

DTIC Science & Technology

2012-03-01

in synoptic storms , extratropical transition and developing hurricanes. Because they rely on lagged covariances from a finite-sized ensemble, they...diagnose predictors of forecast error in synoptic storms , extratropical transition and developing hurricanes. Because they rely on lagged covariances...sensitivities can be used successfully to diagnose predictors of forecast error in synoptic storms (Torn and Hakim 2008), extratropical transition (Torn and

Impact assessment of extreme storm events using a Bayesian network

USGS Publications Warehouse

den Heijer, C.(Kees); Knipping, Dirk T.J.A.; Plant, Nathaniel G.; van Thiel de Vries, Jaap S. M.; Baart, Fedor; van Gelder, Pieter H. A. J. M.

2012-01-01

This paper describes an investigation on the usefulness of Bayesian Networks in the safety assessment of dune coasts. A network has been created that predicts the erosion volume based on hydraulic boundary conditions and a number of cross-shore profile indicators. Field measurement data along a large part of the Dutch coast has been used to train the network. Corresponding storm impact on the dunes was calculated with an empirical dune erosion model named duros+. Comparison between the Bayesian Network predictions and the original duros+ results, here considered as observations, results in a skill up to 0.88, provided that the training data covers the range of predictions. Hence, the predictions from a deterministic model (duros+) can be captured in a probabilistic model (Bayesian Network) such that both the process knowledge and uncertainties can be included in impact and vulnerability assessments.

Examining the effects of hurricanes Matthew and Irma on water quality in the intracoastal waterway, St. Augustine, FL.

NASA Astrophysics Data System (ADS)

Ward, N. D.; Osborne, T.; Dye, T.; Julian, P.

2017-12-01

The last several years have been marked by a high incidence of Atlantic tropical cyclones making landfall as powerful hurricanes or tropical storms. For example, in 2016 Hurricane Matthew devastated parts of the Caribbean and the southeastern United States. In 2017, this region was further battered by hurricanes Irma and Maria. Here, we present water quality data collected in the intracoastal waterway near the Whitney Lab for Marine Bioscience during hurricanes Matthew and Irma, a region that experienced flooding during both storms. YSI Exo 2 sondes were deployed to measure pH, salinity, temperature, dissolved O2, fluorescent dissolved organic matter (fDOM), turbidity, and Chlorophyll-a (Chl-a) on a 15 minute interval. The Hurricane Matthew sonde deployment failed as soon as the storm hit, but revealed an interesting phenomenon leading up to the storm that was also observed during Irma. Salinity in the intracoastal waterway (off the Whitney Lab dock) typically varies from purely marine to 15-20 psu throughout the tidal cycle. However, several days before both storms approached the Florida coast (i.e. when they were near the Caribbean), the salinity signal became purely marine, overriding any tidal signal. Anecdotally, storm drains were already filled up to street level prior to the storm hitting, poising the region for immense flooding and storm surge. The opposite effect was observed after Irma moved past FL. Water became much fresher than normal for several days and it took almost a week to return to "normal" salinity tidal cycles. As both storms hit, turbidity increased by an order of magnitude for a several hour period. fDOM and O2 behaved similar to salinity during and after Irma, showing a mostly marine signal (e.g. higher O2, lower fDOM) in the lead up, and brief switch to more freshwater influence the week after the storm. Chl-a peaked several days after the storm, presumably due to mobilization of nutrient rich flood and waste waters and subsequent algae blooms. These results demonstrate the power of tropical cyclones in altering aquatic biogeochemical conditions days ahead of any noticeable impact and provide a preliminary look at how these events may influence factors such as carbon export and cycling.

Tropical Cyclone Indlala

NASA Technical Reports Server (NTRS)

2007-01-01

On March 14, 2007, storm-weary Madagascar braced for its fourth land-falling tropical cyclone in as many months. Cyclone Indlala was hovering off the island's northeast coast when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite captured this photo-like image at 1:40 p.m. local time (10:40 UTC). Just over a hundred kilometers offshore, the partially cloudy eye at the heart of the storm seems like a vast drain sucking in a disk of swirling clouds. According to reports from the Joint Typhoon Warning Center issued less than three hours after MODIS captured this image, Indlala had winds of 115 knots (132 miles per hour), with gusts up to 140 knots (161 mph). Wave heights were estimated to be 36 feet. At the time of the report, the storm was predicted to intensify through the subsequent 12-hour period, to turn slightly southwest, and to strike eastern Madagascar as a Category 4 storm with sustained winds up to 125 knots (144 mph), and gusts up to 150 knots (173 mph). According to Reuters AlertNet news service, Madagascar's emergency response resources were taxed to their limit in early March 2007 as a result of extensive flooding in the North, drought and food shortages in the South, and three previous hits from cyclones in the preceding few months: Bondo in December 2006, Clovis in January 2007, and Gamede in February.

Testing GIC Mitigation Protocols by Modelling Transformer-Level GIC Flow in New Zealand's Electrical Transmission Grid

NASA Astrophysics Data System (ADS)

Divett, T.; Ingham, M.; Rodger, C. J.; Richardson, G. S.; Beggan, C.; Thomson, A. W. P.; Dalzell, M.; Mac Manus, D. H.

2017-12-01

Transformers in the South Island of Transpower New Zealand Ltd's electrical transmission network have been impacted by geomagnetically induced currents (GIC) during geomagnetic storms, including the November 2001 event. We aim to make recommendations that lead to improving mitigation strategies for reducing these impacts during extreme events. We have adapted a thin-sheet electromagnetic and GIC network modelling approach that has previously been successfully used in the UK to New Zealand's geology and transmission network. In this presentation we show how we have used this approach to explore Transpower's mitigation procedure as well as alternative mitigation options for reducing the impact of space weather on the network. In order to compare modelled GIC with what has been described as `possibly the best GIC dataset in the world' (Boteler and Pirjola, Pers. Comm. 2016) our model includes every transformer and every high voltage transmission line in the South Island network. This level of detail was required to match the transformer level observations of GIC in the network and to appropriately assess the mitigation options at the level where the damage to power networks occurs. We found that removing a single generator at a central power station and four transmission lines is enough to effectively redistribute GIC away from transformers that have previously experienced very high GIC (as shown in Figure). The redistributed GIC is less damaging to the transformers that it is redistributed to due to lower total GIC at those locations. In the past the impact of GIC on transformers has occurred in the first two minutes of a storm. Hence, mitigation strategies that currently rely on human intervention and involving delays of up to 15 minutes may need to be initiated very rapidly, in a significant departure from Transpower's existing protocol. Reducing delays should significantly reduce the potential for damage in a storm equivalent to the 2001 event. During an extreme storm we expect GIC of 300 A or more to flow through multiple transformers across both islands. In the case of an extreme storm we suggest the more drastic approach of floating the entire network to reduce the potential for damage while retaining power supply to the majority of the country.

Identifying hydrologically sensitive areas using LiDAR DEMs to mitigate critical source areas of diffuse pollution: development and application

NASA Astrophysics Data System (ADS)

Thomas, Ian; Jordan, Phil; Mellander, Per-Erik; Fenton, Owen; Shine, Oliver; hUallacháin, Daire Ó.; Creamer, Rachel; McDonald, Noeleen; Dunlop, Paul; Murphy, Paul

2016-04-01

Identifying critical source areas (CSAs) of diffuse pollution in agricultural catchments requires the accurate identification of hydrologically sensitive areas (HSAs) at highest propensity for generating surface runoff and transporting pollutants such as phosphorus (P). A new GIS-based HSA Index is presented that identifies HSAs at the sub-field scale. It uses a soil topographic index (STI) and accounts for the hydrological disconnection of overland flow via topographic impediment from flow sinks such as hedgerows and depressions. High resolution (0.25-2 m) LiDAR Digital Elevation Models (DEMs) are utilised to capture these microtopographic controls on flow pathways and hydrological connectivity. The HSA Index was applied to four agricultural catchments (~7.5-12 km2) with contrasting topography and soil types. Catchment HSA sizes were estimated using high resolution rainfall-quickflow measurements during saturated winter storm events in 2009-2014, and mapped using the HSA Index. HSA sizes ranged from 1.6-3.4% of the catchment area during median storm events and 2.9-8.5% during upper quartile events depending on whether well or poorly drained soils dominated, which validated HSA Index value distributions. Total flow sink volume capacities ranged from 8,298-59,584 m3 and caused 8.5-24.2% of overland-flow-generating-areas and 16.8-33.4% of catchment areas to become hydrologically disconnected from the open drainage channel network. HSA maps identified 'delivery points' along surface runoff pathways where transported pollutants such as P are delivered to the open drainage network. Using these as proposed locations for targeting mitigation measures such as riparian buffer strips (RBS) reduced costs compared to blanket implementation within an example agri-environment scheme by 66% and 91% over 1 and 5 years respectively, which included LiDAR DEM acquisition costs. Considering that HSAs are often the dominant P CSA factor in agricultural catchments and can override source pressures, targeting measures at HSAs is potentially a more sustainable, cost-effective and policy-applicable strategy for mitigating diffuse pollution.

Case study: Rainfall partitioning across a natural-to-urban forest gradient during an extreme rain event

NASA Astrophysics Data System (ADS)

Akin, B. H.; Van Stan, J. T., II; Cote, J. F.; Jarvis, M. T.; Underwood, J.; Friesen, J.; Hildebrandt, A.; Maldonado, G.

2017-12-01

Trees' partitioning of rainfall is an important first process along the rainfall-to-runoff pathway that has economically significant influences on urban stormwater management. However, important knowledge gaps exist regarding (1) its role during extreme storms and (2) how this role changes as forest structure is altered by urbanization. Little research has been conducted on canopy rainfall partitioning during large, intense storms, likely because canopy water storage is rapidly overwhelmed (i.e., 1-3 mm) by short duration events exceeding, for example, 80 mm of rainfall. However, canopy structure controls more than just storage; it also affects the time for rain to drain to the surface (becoming throughfall) and the micrometeorological conditions that drive wet canopy evaporation. In fact, observations from an example extreme ( 100 mm with maximum 5-minute intensities exceeding 55 mm/h) storm across a urban-to-natural gradient in pine forests in southeast Georgia (USA), show that storm intensities were differentially dampened by 33% (tree row), 28% (forest fragment), and 17% (natural forests). In addition, maximum wet canopy evaporation rates were higher for the exposed tree row (0.18 mm/h) than for the partially-enclosed fragment canopy (0.14 mm/h) and the closed canopy natural forest site (0.11). This resulted in interception percentages decreasing from urban-to-natural stand structures (25% to 16%). A synoptic analysis of the extreme storm in this case study also shows that the mesoscale meteorological conditions that developed the heavy rainfall is expected to occur more often with projected climate changes.

Electrification in winter storms and the analysis of thunderstorm overflight

NASA Technical Reports Server (NTRS)

Brook, Marx

1991-01-01

The emergence of 24 hr operational lightning detection networks has led to the finding that positive lightning strokes, although still much fewer in number than the normal negative strokes, are present in summer and winter storms. Recent papers address the importance of understanding the meteorological conditions which lead to a dominance of one polarity of stroke over another; the appearance of positive strokes at the end of a storm appeared to presage the end-of-storm downdraft and subsidence leading to downburst activity. It is beginning to appear that positive strokes may be important meteorological indicators. Significant research accomplishments on the following topics are addressed: (1) a study to verify that the black boxes used in the lightning networks to detect both negative and positive strokes to ground were accurate; (2) the use of slow tails to determine the polarity of distant lightning; (3) lightning initiation in winter vs. summer storms; (4) the upgrade of sensors for the measurement of electric field signals associated with lightning; (5) the analysis of lightning flash records from storms between 40 and 125 km from the sensor; and (6) an interesting aspect of the initiation process which involves the physical processes driving the stepped leader. The focus of current research and future research plans are presented.

The NASA Severe Thunderstorm Observations and Regional Modeling (NASA STORM) Project

NASA Technical Reports Server (NTRS)

Schultz, Christopher J.; Gatlin, Patrick N.; Lang, Timothy J.; Srikishen, Jayanthi; Case, Jonathan L.; Molthan, Andrew L.; Zavodsky, Bradley T.; Bailey, Jeffrey; Blakeslee, Richard J.; Jedlovec, Gary J.

2016-01-01

The NASA Severe Storm Thunderstorm Observations and Regional Modeling(NASA STORM) project enhanced NASA’s severe weather research capabilities, building upon existing Earth Science expertise at NASA Marshall Space Flight Center (MSFC). During this project, MSFC extended NASA’s ground-based lightning detection capacity to include a readily deployable lightning mapping array (LMA). NASA STORM also enabled NASA’s Short-term Prediction and Research Transition (SPoRT) to add convection allowing ensemble modeling to its portfolio of regional numerical weather prediction (NWP) capabilities. As a part of NASA STORM, MSFC developed new open-source capabilities for analyzing and displaying weather radar observations integrated from both research and operational networks. These accomplishments enabled by NASA STORM are a step towards enhancing NASA’s capabilities for studying severe weather and positions them for any future NASA related severe storm field campaigns.

Climate Change Implications and Use of Early Warning Systems for Global Dust Storms

NASA Astrophysics Data System (ADS)

Harriman, L.

2014-12-01

Increased changes in land cover and global climate have led to increased frequency and/or intensity of dust storms in some regions of the world. Early detection and warning of dust storms, in conjunction with effective and widespread information broadcasts, will be essential to the prevention and mitigation of future risks and impacts to people and the environment. Since frequency and intensity of dust storms can vary from region to region, there is a demonstrated need for more research to be conducted over longer periods of time to analyze trends of dust storm events [1]. Dust storms impact their origin area, but also land, water and people a great distance away from where dust finally settles [2, 3]. These transboundary movements and accompanying impacts further warrant the need for global collaboration to help predict the onset, duration and path of a dust storm. Early warning systems can help communicate when a dust storm is occurring, the projected intensity of the dust storm and its anticipated physical impact over a particular geographic area. Development of regional dust storm models, such as CUACE/Dust for East Asia, and monitoring networks, like the Sand and Dust Storm Warning Network operated by the World Meteorological Organization, and the use of remote sensing and satellite imagery derived products [4], including MODIS, are currently being incorporated into early warning and monitoring initiatives. However, to increase future certainty of impacts of dust storms on vulnerable populations and ecosystems, more research is needed to analyze the influences of human activities, seasonal variations and long-term climatic patterns on dust storm generation, movement and impact. Sources: [1] Goudie, A.S. (2009), Dust storms: recent developments, J Environ. Manage., 90. [2] Lee, H., and Liu, C. (2004), Coping with dust storm events: information, impacts, and policymaking in Taiwan, TAO, 15(5). [3] Marx, S.K., McGowan, H.A., and Balz, K.S. (2009), Long-range dust transport from eastern Australia: a proxy for Holocene aridity and ENSO-type climate variability, Earth Planet Sci. Lett., 282. [4] Kimura, R. (2012), Factors contributing to dust storms in source regions producing the yellow-sand phenomena observed in Japan from 1993 to 2002, J. Arid Environ. 80

Documentation and hydrologic analysis of Hurricane Sandy in New Jersey, October 29–30, 2012

USGS Publications Warehouse

Suro, Thomas P.; Deetz, Anna; Hearn, Paul

2016-11-17

In 2012, a late season tropical depression developed into a tropical storm and later a hurricane. The hurricane, named “Hurricane Sandy,” gained strength to a Category 3 storm on October 25, 2012, and underwent several transitions on its approach to the mid-Atlantic region of the eastern coast of the United States. By October 28, 2012, Hurricane Sandy had strengthened into the largest hurricane ever recorded in the North Atlantic and was tracking parallel to the east coast of United States, heading toward New Jersey. On October 29, 2012, the storm turned west-northwest and made landfall near Atlantic City, N.J. The high winds and wind-driven storm surge caused massive damage along the entire coastline of New Jersey. Millions of people were left without power or communication networks. Many homes were completely destroyed. Sand dunes were eroded, and the barrier island at Mantoloking was breached, connecting the ocean with Barnegat Bay.Several days before the storm made landfall in New Jersey, the U.S. Geological Survey (USGS) made a decision to deploy a temporary network of storm-tide sensors and barometric pressure sensors from Virginia to Maine to supplement the existing USGS and National Oceanic and Atmospheric Administration (NOAA) networks of permanent tide monitoring stations. After the storm made landfall, the USGS conducted a sensor data recovery and high-water-mark collection campaign in cooperation with the Federal Emergency Management Agency (FEMA).Peak storm-tide elevations documented at USGS tide gages, tidal crest-stage gages, temporary storm sensor locations, and high-water-mark sites indicate the area from southern Monmouth County, N.J., north through Raritan Bay, N.J., had the highest peak storm-tide elevations during this storm. The USGS tide gages at Raritan River at South Amboy and Raritan Bay at Keansburg, part of the New Jersey Tide Telemetry System, each recorded peak storm-tide elevations of greater than 13 feet (ft)—more than 5 ft higher than the previously recorded period-of-record maximum. A comparison of peak storm-tide elevations to preliminary FEMA Coastal Flood Insurance Study flood elevations indicated that these areas experienced the highest recurrence intervals along the coast of New Jersey. Analysis showed peak storm-tide elevations exceeded the 100-year FEMA flood elevations in many parts of Middlesex, Union, Essex, Hudson, and Bergen Counties, and peak storm-tide elevations at many locations in Monmouth County exceeded the 500-year recurrence interval.A level 1 HAZUS (HAZards United States) analysis was done for the counties in New Jersey affected by flooding to estimate total building stock losses. The aggregated total building stock losses estimated by HAZUS for New Jersey, on the basis of the final inundation verified by USGS high-water marks, was almost $19 billion. A comparison of Hurricane Sandy with historic coastal storms showed that peak storm-tide elevations associated with Hurricane Sandy exceeded most of the previously documented elevations associated with the storms of December 1992, March 1962, September 1960, and September 1944 at many coastal communities in New Jersey. This scientific investigation report was prepared in cooperation with FEMA to document flood processes and flood damages resulting from this storm and to assist in future flood mitigation actions in New Jersey.

Potential Release Site Sediment Concentrations Correlated to Storm Water Station Runoff through GIS Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

C.T. McLean

2005-06-01

This research examined the relationship between sediment sample data taken at Potential Release Sites (PRSs) and storm water samples taken at selected sites in and around Los Alamos National Laboratory (LANL). The PRSs had been evaluated for erosion potential and a matrix scoring system implemented. It was assumed that there would be a stronger relationship between the high erosion PRSs and the storm water samples. To establish the relationship, the research was broken into two areas. The first area was raster-based modeling, and the second area was data analysis utilizing the raster based modeling results and the sediment and stormmore » water sample results. Two geodatabases were created utilizing raster modeling functions and the Arc Hydro program. The geodatabase created using only Arc Hydro functions contains very fine catchment drainage areas in association with the geometric network and can be used for future contaminant tracking. The second geodatabase contains sub-watersheds for all storm water stations used in the study along with a geometric network. The second area of the study focused on data analysis. The analytical sediment data table was joined to the PRSs spatial data in ArcMap. All PRSs and PRSs with high erosion potential were joined separately to create two datasets for each of 14 analytes. Only the PRSs above the background value were retained. The storm water station spatial data were joined to the table of analyte values that were either greater than the National Pollutant Discharge Elimination System (NPDES) Multi-Sector General Permit (MSGP) benchmark value, or the Department of Energy (DOE) Drinking Water Defined Contribution Guideline (DWDCG). Only the storm water stations were retained that had sample values greater than the NPDES MSGP benchmark value or the DOE DWDCG. Separate maps were created for each analyte showing the sub-watersheds, the PRSs over background, and the storm water stations greater than the NPDES MSGP benchmark value or the DOE DWDCG. Tables were then created for each analyte that listed the PRSs average value by storm water station allowing a tabular view of the mapped data. The final table that was created listed the number of high erosion PRSs and regular PRSs over background values that were contained in each watershed. An overall relationship between the high erosion PRSs or the regular PRSs and the storm water stations was not identified through the methods used in this research. However, the Arc Hydro data models created for this analysis were used to track possible sources of contamination found through sampling at the storm water gaging stations. This geometric network tracing was used to identify possible relationships between the storm water stations and the PRSs. The methods outlined for the geometric network tracing could be used to find other relationships between the sites. A cursory statistical analysis was performed which could be expanded and applied to the data sets generated during this research to establish a broader relationship between the PRSs and storm water stations.« less

Catheter ablation of fatal ventricular tachyarrhythmias storm in acute coronary syndrome--role of Purkinje fiber network.

PubMed

Enjoji, Yoshihisa; Mizobuchi, Masahiro; Muranishi, Hiromi; Miyamoto, Chinae; Utsunomiya, Makoto; Funatsu, Atsushi; Kobayashi, Tomoko; Nakamura, Shigeru

2009-12-01

Ventricular fibrillation (VF) or ventricular tachycardia (VT) storm is a life-threatening arrhythmia. Antiarrhythmic drugs (AADs) are not necessarily effective to rescue life from such conditions. Catheter ablation (CA) targeting triggering premature ventricular contractions (PVCs) of VF or VT that originates from Purkinje fiber network (PFN) is reported to be effective, especially in idiopathic patients. However, in condition of acute coronary syndrome (ACS), the efficacy of CA is not well understood. To clarify the usefulness of CA as an alternative way to AADs, we performed CA in four patients with VF or VT storm. The Purkinje potential was seen just before the myocardial ventricular wave during sinus rhythm that became more prominent and double components during the initiating PVC at the targeted area. Following CA, spontaneous episodes of VF or VT were no longer observed. CA is an efficacious way to bail out PFN-related VF or VT storm even in ACS.

The North Alabama Severe Thunderstorm Observations, Research, and Monitoring Network (STORMnet)

NASA Technical Reports Server (NTRS)

Goodman, S. J.; Blakeslee, R.; Christian, H.; Boccippio, D.; Koshak, W.; Bailey, J.; Hall, J.; Bateman, M.; McCaul, E.; Buechler, D.;

U.S. Geological Survey Catskill/Delaware Water-Quality Network: Water-Quality Report Water Year 2006

USGS Publications Warehouse

McHale, Michael R.; Siemion, Jason

2010-01-01

The U.S. Geological Survey operates a 60-station streamgaging network in the New York City Catskill/Delaware Water Supply System. Water-quality samples were collected at 13 of the stations in the Catskill/Delaware streamgaging network to provide resource managers with water-quality and water-quantity data from the water-supply system that supplies about 85 percent of the water needed by the more than 9 million residents of New York City. This report summarizes water-quality data collected at those 13 stations plus one additional station operated as a part of the U.S. Environmental Protection Agency's Regional Long-Term Monitoring Network for the 2006 water year (October 1, 2005 to September 30, 2006). An average of 62 water-quality samples were collected at each station during the 2006 water year, including grab samples collected every other week and storm samples collected with automated samplers. On average, 8 storms were sampled at each station during the 2006 water year. The 2006 calendar year was the second warmest on record and the summer of 2006 was the wettest on record for the northeastern United States. A large storm on June 26-28, 2006, caused extensive flooding in the western part of the network where record peak flows were measured at several watersheds.

Latitudinal Dependence of the Energy Input into the Mesosphere by High Energy Electrons

NASA Technical Reports Server (NTRS)

Wagner, C. U.; Nikutowski, B.; Ranta, H.

1984-01-01

Night-time ionspheric absorption measurements give the possibility to study the precipitation of high energy electrons into the mesosphere during and after magnetospheric storms. The uniform Finnish riometer network was used together with measurements from Kuhlungsborn and Collm (GDR) to investigate the night-time absorption as a function of latitude (L=6.5 to 2.5) and storm-time for seven storms. The common trends visible in all these events are summarized in a schematic average picture, showing the distribution of increased ionospheric absorption as a function of latitude (L value) and storm-time.

Reconnaissance Study of the Hydrology of American Memorial Park, Island of Saipan, Commonwealth of the Northern Mariana Islands

USGS Publications Warehouse

Perreault, Jeff A.

2007-01-01

American Memorial Park, a unit of the National Park Service on the Island of Saipan, includes among its features a 27-acre estuarine system that has become a rarity within the Commonwealth of the Northern Mariana Islands. The estuarine system's mosaic of marshy areas interspersed with emergent wetlands and mixed wet forests provides critical habitat for various migratory and resident waterfowl, including two Federally listed endangered species: the Marianas gallinule (Gallinula chloropus guami) and the nightingale reed warbler (Acrocephalus luscinia). With sensitivity to the park's ecologic assets and the uncertainty associated with locally rapid urbanization, a need to better understand the hydrology of American Memorial Park was recognized. To address that need, a reconnaissance study of the park was undertaken during August and September 2005. The goals of the study were (1) to describe the occurrence and salinity of surface and ground water within the park; (2) to develop a hydrologic model of the park area of the island, with emphasis on the 27-acre estuarine system; and (3) to identify additional data needed to further develop this model. With regard to surface water, three freshwater inputs to the park's natural wetland are possible: direct rainfall, seaward-flowing ground water, and overland flow. Direct rainfall, which is an important source of freshwater to the wetland, commonly exceeds evapotranspiration both seasonally and per storm. The seaward flow of ground water is likely to be a source of freshwater to the wetland because ground water generally has an upward vertical component in the nearshore environment. Overland flow upgradient of the park could potentially contribute a significant input of freshwater during periods of intense rainfall, but roads that flank the park's perimeter act as a barrier to surficial inflows. During the reconnaissance, four discrete bodies, or zones, of surface water were observed within the park's natural wetland. Conductivity within these surface-water zones typically ranged from 1,540 to 4,370 microsiemens per centimeter (?S/cm) at 25?C, although values as low as 829 and as high as 8,750 ?S/cm were measured. As a result of these observations, the American Memorial Park wetland area meets the definition criteria of an estuarine system that is dominantly oligohaline. Conductivity was also measured in a constructed wetland that was built within the park to augment the storm-drainage infrastructure of the village of Garapan. Reverse-osmosis facilities, in operation at hotels adjacent to the park, have historically discharged highly saline wastewater into the storm-drainage system. This collective storm and wastewater flow is routed into the constructed wetland and from there into the ocean. The conductivity of water in the constructed wetland ranged from 45,000 to 62,500 ?S/cm, exceeding nominal seawater values by as much as 25 percent, with the highest conductivities recorded near discharging storm drains. With regard to ground water, the reconnaissance included installation of a ground-water-monitoring network. Data collected from this network identified the presence of freshwater underlying the park and indicated that surface water is directly connected to ground water in the natural wetland because the water levels of both surface water and ground water directly varied with the tide. Conductivities of ground-water samples from wells in the monitoring network indicated that ground-water salinity was geographically related: conductivities were lower (801-2,490 ?S/cm) in surficially dry areas, intermediate (6,090-9,180 ?S/cm) in natural-wetland areas, and higher (18,250-27,700 ?S/cm) in areas adjacent to the constructed wetland and its associated ocean-discharge channel. Synoptic water-level surveys were made to enhance understanding of the spatial expression of the water table; they were scheduled to overlap with peak and trough tidal signals to enable limited characteri

Using Bayesian Network as a tool for coastal storm flood impact prediction at Varna Bay (Bulgaria, Western Black Sea)

NASA Astrophysics Data System (ADS)

Valchev, Nikolay; Eftimova, Petya; Andreeva, Nataliya; Prodanov, Bogdan

2017-04-01

Coastal zone is among the fastest evolving areas worldwide. Ever increasing population inhabiting coastal settlements develops often conflicting economic and societal activities. The existing imbalance between the expansion of these activities, on one hand, and the potential to accommodate them in a sustainable manner, on the other, becomes a critical problem. Concurrently, coasts are affected by various hydro-meteorological phenomena such as storm surges, heavy seas, strong winds and flash floods, which intensities and occurrence frequency is likely to increase due to the climate change. This implies elaboration of tools capable of quick prediction of impact of those phenomena on the coast and providing solutions in terms of disaster risk reduction measures. One such tool is Bayesian network. Proposed paper describes the set-up of such network for Varna Bay (Bulgaria, Western Black Sea). It relates near-shore storm conditions to their onshore flood potential and ultimately to relevant impact as relative damage on coastal and manmade environment. Methodology for set-up and training of the Bayesian network was developed within RISC-KIT project (Resilience-Increasing Strategies for Coasts - toolKIT). Proposed BN reflects the interaction between boundary conditions, receptors, hazard, and consequences. Storm boundary conditions - maximum significant wave height and peak surge level, were determined on the basis of their historical and projected occurrence. The only hazard considered in this study is flooding characterized by maximum inundation depth. BN was trained with synthetic events created by combining estimated boundary conditions. Flood impact was modeled with the process-based morphodynamical model XBeach. Restaurants, sport and leisure facilities, administrative buildings, and car parks were introduced in the network as receptors. Consequences (impact) are estimated in terms of relative damage caused by given inundation depth. National depth-damage (susceptibility) curves were used to define the percentage of damage ranked as low, moderate, high and very high. Besides previously described components, BN includes also two hazard influencing disaster risk reduction (DRR) measures: re-enforced embankment of Varna Port wall and beach nourishment. As a result of training process the network is able to evaluate spatially varying hazards and damages for specific storm conditions. Moreover, it is able to predict where on the site the highest impact would occur and to quantify the mitigation capacity of proposed DRR measures. For example, it is estimated that storm impact would be considerably reduced in present conditions but vulnerability would be still high in climate change perspective.

Tritium recapture behavior at a nuclear power reactor due to airborne releases.

PubMed

Harris, Jason T; Miller, David W; Foster, Doug W

2008-08-01

This paper describes the initiatives taken by Cook Nuclear Plant to study the on-site behavior of recaptured tritium released in its airborne effluents. Recapture is the process where a released radioactive effluent, in this case tritium, is brought back on-site through some mechanism. Precipitation, shifts in wind direction, or anthropogenic structures that restrict or alter effluent movement can all lead to recapture. The investigation was started after tritium was detected in the north storm drain outfall. Recent inadvertent tritium releases by several other nuclear power plants, many of which entered the groundwater, have led to increased surveillance and scrutiny by regulatory authorities and the general public. To determine the source of tritium in the outfall, an on-site surface water, well water, rainwater and air-conditioning condensate monitoring program was begun. Washout coefficients were also determined to compare with results reported by other nuclear power plants. Program monitoring revealed detectable tritium concentrations in several precipitation sample locations downwind of the two monitored containment building release vents. Tritium was found in higher concentrations in air-conditioning condensate, with a mean value of 528 Bq L(-1) (14,300 pCi L(-1)). The condensate, and to a lesser extent rainwater, were contributing to the tritium found in the north storm drain outfall. Maximum concentration values for each sample type were used to estimate the most conservative dose. A maximum dose of 1.1 x 10(-10) mSv (1.1 x 10(-8) mrem) total body was calculated to determine the health impact of the tritium detected.

Leveraging Spatial Data to Assess Where Sewers Leak and Impinge on Urban Water Quality

NASA Astrophysics Data System (ADS)

Holden, P. A.; Roehrdanz, P.; Lee, D. G.; Feraud, M.; Maier, M.; Means, J. C.; Snyder, S.

2017-12-01

In the modern urban water environment (UWE), engineered systems provide wastewater collection, treatment, and reuse; stormwater and graywater management; and potable water treatment, distribution and conservation. Underpinning such systems are physical, private and public, infrastructures whose integrities impinge on major goals of protecting groundwater and surface water resources, managing flooding, and securing safe drinking water. Here we study sanitary sewers, i.e. the main pipes in wastewater collection systems that improve public health by reducing pathogen exposure, and that afford reclaiming water for beneficial reuse. We ask: what is the relationship between sanitary sewer integrity and nearby water quality? Research methods include acquiring spatially defined sewer metadata that are analyzed using a published pipe leakage algorithm with variables of age, depth, materials of construction, length, diameter, slope, and nature of overburden. By executing the algorithm within a geographical information system (GIS), coupled with relating leakage probabilities to shallow groundwater table proximities—also digitally assembled, from well depth data—maps of wastewater exfiltration scores were produced for a city. Field sampling shallow groundwater allowed assessing concentrations of wastewater indicator compounds including personal care products and pharmaceuticals (PCPPs), and showing positive relationships between wastewater exfiltration scores and tryptophan-like fluorescence (TLF), reactive nitrogen species, an artificial sweetener acesulfame, and a stable isotope of oxygen (δ18O). The approach is extended to surface waters, where exfiltrating wastewater may transport from leaking sanitary sewers through the unsaturated zone to nearby storm drains or to storm drains that are submerged in contaminated groundwater. Spatially assessing sewer interactions within the UWE, as such, could aid urban infrastructure management and investment.

Measuring storm tide and high-water marks caused by Hurricane Sandy in New York: Chapter 2

USGS Publications Warehouse

Simonson, Amy E.; Behrens, Riley

2015-01-01

In response to Hurricane Sandy, personnel from the U.S. Geological Survey (USGS) deployed a temporary network of storm-tide sensors from Virginia to Maine. During the storm, real-time water levels were available from tide gages and rapid-deployment gages (RDGs). After the storm, USGS scientists retrieved the storm-tide sensors and RDGs and surveyed high-water marks. These data demonstrate that the timing of peak storm surge relative to astronomical tide was extremely important in southeastern New York. For example, along the south shores of New York City and western Suffolk County, the peak storm surge of 6–9 ft generally coincided with the astronomical high tide, which resulted in substantial coastal flooding. In the Peconic Estuary and northern Nassau County, however, the peak storm surge of 9 ft and nearly 12 ft, respectively, nearly coincided with normal low tide, which helped spare these communities from more severe coastal flooding.

Geomagnetically induced currents in the Irish power network during geomagnetic storms

NASA Astrophysics Data System (ADS)

Blake, Seán. P.; Gallagher, Peter T.; McCauley, Joe; Jones, Alan G.; Hogg, Colin; Campanyà, Joan; Beggan, Ciarán. D.; Thomson, Alan W. P.; Kelly, Gemma S.; Bell, David

2016-12-01

Geomagnetically induced currents (GICs) are a well-known terrestrial space weather hazard. They occur in power transmission networks and are known to have adverse effects in both high-latitude and midlatitude countries. Here we study GICs in the Irish power transmission network (geomagnetic latitude 54.7-58.5°N) during five geomagnetic storms (6-7 March 2016, 20-21 December 2015, 17-18 March 2015, 29-31 October 2003, and 13-14 March 1989). We simulate electric fields using a plane wave method together with two ground resistivity models, one of which is derived from magnetotelluric measurements (magnetotelluric (MT) model). We then calculate GICs in the 220, 275, and 400 kV transmission network. During the largest of the storm periods studied, the peak electric field was calculated to be as large as 3.8 V km-1, with associated GICs of up to 23 A using our MT model. Using our homogenous resistivity model, those peak values were 1.46 V km-1 and 25.8 A. We find that three 400 and 275 kV substations are the most likely locations for the Irish transformers to experience large GICs.

Invetigation of Travelling Ionospheric Disturbances during the Memorial Day Weekend Geomagnetic Storm of 27 - 28 OF may, 2017 Over North America.

NASA Astrophysics Data System (ADS)

Jonah, O. F.; Coster, A. J.; Zhang, S.; Goncharenko, L. P.; Bhatt, A.; Kendall, E. A.

2017-12-01

Using the large GNSS network over North America (70 - 125oW and 25 - 50oN) with a spatial resolution of 0.1 x 0.1o in latitude and longitude and temporal resolution of 1min, we investigate the ionospheric perturbations associated with Traveling Ionospheric Disturbances (TIDs) on 2017 Memorial Day weekend's geomagnetic storm that occurred on the 27 and 28 of May, 2017. Our results were compared with images from the Mid-latitude All-Sky-imager Network for GeoSpace Observation (MANGO) and radio occultation satellite data. The storm was intense, featuring a southward interplanetary field (Bz) below 20 nT for about 4 hr, with a strong increase in the AE from 200 to 1300 nT and the Dst and kp indies were below 120 nT, and above 7 units, respectively. Both medium and large scale TIDs were observed, and their velocity, wavelength, wavefront and period throughout the storm are analyzed. Results show the presence of both poleward and equator-ward propagation of the TIDs. The features of TIDs obtained from keograms and 2-D TEC maps from GNSS-TEC are compared with those obtained from the all-sky imaging system during storm period. Finally, we compared the behavior of TIDs during Memorial Day weekend geomagnetic storm with the TIDs during the May quiet periods.

Geochemical and isotopic tracing of water in nested southern Minnesota corn-belt watersheds.

PubMed

Magner, J A; Alexander, S C

2002-01-01

Land-use changes over the last century in southern Minnesota have influenced riverine water chemistry. A nested watershed approach was used to examine hydrologic pathways of water movement in this now agriculturally intensive region. From field scale subsurface tile-drains of the Beauford ditch to the respective outlets of the Cobb River and Blue Earth River, more than 125 samples were collected for major dissolved ions and isotopes between March 1994 and June 1996 over a range of climatic conditions that included snowmelt and storm-flows. Results indicate that riverine water chemistry is dominated by subsurface tile-drained row crop agriculture. In the mid-1990s, regional ground water discharge into the Cobb and Blue Earth Rivers comprised less than 10% of the total flow based on ionic mixing calculations. Ammonia, present in manure or as anhydrous, is readily exchanged in the soil. This ion exchange releases increasing ratios of magnesium, sodium and strontium relative to calcium, the dominant cation. Soil thaw and snowmelt recharge influenced March-April tile-drain and ditch water isotopic values. Light deltaD values increased as spring infiltration-derived water was displaced from the soil zone by heavier summer precipitation. Delta15N followed a similar but opposite pattern with relatively heavy March-April tile-drain and ditch values trending to lighter delta15N through the growing season. The future of southern Minnesota riverine water quality is closely linked to the management of the landscape. To improve the riverine environment, land owners and managers will need to address cropping systems, fertilization practices and drainage.

Temporal Dynamics in the Concentration, Flux, and Optical Properties of Tree-derived Dissolved Organic Matter (Tree-DOM) in an Epiphyte-laden Oak-cedar Forest.

NASA Astrophysics Data System (ADS)

Whitetree, A.; Van Stan, J. T., II; Wagner, S.; Guillemette, F.; Lewis, J.; Silva, L.; Stubbins, A.

2017-12-01

Studies on the fate and transport of dissolved organic matter (DOM) along the rainfall-to-discharge flow pathway typically begin in streams or soils, neglecting the initial enrichment of rainfall with DOM during contact with plant canopies. However, rain water can gather significant amounts of tree-derived DOM (tree-DOM) when it drains from the canopy, as throughfall, and down the stem, as stemflow. We examined the temporal variability of event-scale tree-DOM concentrations, yield, and optical (light absorbance and fluorescence) characteristics from an epiphyte-laden Quercus virginiana-Juniperus virginiana forest on Skidaway Island, Savannah, Georgia (USA). All tree-DOM fluxes were highly enriched compared to rainfall and epiphytes further increased concentrations. Stemflow DOC concentrations were greater than throughfall across study species, yet larger throughfall water yields produced greater DOC yields versus stemflow. Tree-DOM optical characteristics indicate it is aromatic-rich with FDOM dominated by humic-like fluorescence, containing 10-20% protein-like (tryptophan-like) fluorescence. Storm size was the only storm condition that strongly correlated with tree-DOM concentration and flux; however, throughfall and stemflow optical characteristics varied little across a wide range of storm conditions (from low magnitude events to intense tropical storms). Annual tree-DOM yields from the study forest (0.8-46 g-C m-2 yr-1) compared well to other yields along the rainfall-to- discharge flow pathway, exceeding DOM yields from some river watersheds.

Effects of the May 5-6, 1973, storm in the Greater Denver area, Colorado

USGS Publications Warehouse

Hansen, Wallace R.

1973-01-01

Rain began falling on the Greater Denver area the evening of Saturday, May 5, 1973, and continued through most of Sunday, May 6. Below about 7,000 feet altitude, the precipitation was mostly rain; above that altitude, it was mostly snow. Although the rate of fall was moderate, at least 4 inches of rain or as much as 4 feet of snow accumulated in some places. Sustained precipitation falling at a moderate rate thoroughly saturated the ground and by midday Sunday sent most of the smaller streams into flood stage. The South Platte River and its major tributaries began to flood by late Sunday evening and early Monday morning. Geologic and hydrologic processes activated by the May 5-6 storm caused extensive damage to lands and to manmade structures in the Greater Denver area. Damage was generally most intense in areas where man had modified the landscape--by channel constrictions, paving, stripping of vegetation and topsoil, and oversteepening of hillslopes. Roads, bridges, culverts, dams, canals, and the like were damaged or destroyed by erosion and sedimentation. Streambanks and structures along them were scoured. Thousands of acres of croplands, pasture, and developed urban lands were coated with mud and sand. Flooding was intensified by inadequate storm sewers, blocked drains, and obstructed drainage courses. Saturation of hillslopes along the Front Range caused rockfalls, landslides, and mudflows as far west as Berthoud Pass. Greater attention to geologic conditions in land-use planning, design, and construction would minimize storm damage in the future.

Aircraft measurements and analysis of severe storms: 1975 field experiment

NASA Technical Reports Server (NTRS)

Sinclair, P. C.

1976-01-01

Three aircraft and instrumentation systems were acquired in support of the severe storm surveillance program. The data results indicate that the original concept of a highly mobile research aircraft capability for obtaining detailed measurements of wind, temperature, dew point, etc., near and within specifically designated severe storms is entirely feasible and has been demonstrated for the first time by this program. This program is unique in that it is designed to be highly mobile in order to move to and/or with the developing storm systems to obtain the necessary measurements. Previous programs have all been fixed to a particular location and therefore have had to wait for the storms to come within their network. The present research is designed around a highly mobile aircraft measurements group in order to maximize the storm cases during the field measurements program.

Spatial characteristics of observed precipitation fields: A catalog of summer storms in Arizona, Volume 2

NASA Technical Reports Server (NTRS)

Fennessey, N. M.; Eagleson, P. S.; Qinliang, W.; Rodriguez-Iturbe, I.

1986-01-01

The parameters of the conceptual model are evaluated from the analysis of eight years of summer rainstorm data from the dense raingage network in the Walnut Gulch catchment near Tucson, Arizona. The occurrence of measurable rain at any one of the 93 gages during a noon to noon day defined a storm. The total rainfall at each of the gages during a storm day constituted the data set for a single storm. The data are interpolated onto a fine grid and analyzed to obtain: an isohyetal plot at 2 mm intervals, the first three moments of point storm depth, the spatial correlation function, the spatial variance function, and the spatial distribution of the total storm depth. The description of the data analysis and the computer programs necessary to read the associated data tapes are presented.

Spatial characteristics of observed precipitation fields: A catalog of summer storms in Arizona, Volume 1

NASA Technical Reports Server (NTRS)

Fennessey, N. M.; Eagleson, P. S.; Qinliang, W.; Rodrigues-Iturbe, I.

1986-01-01

Eight years of summer raingage observations are analyzed for a dense, 93 gage, network operated by the U. S. Department of Agriculture, Agricultural Research Service, in their 150 sq km Walnut Gulch catchment near Tucson, Arizona. Storms are defined by the total depths collected at each raingage during the noon to noon period for which there was depth recorded at any of the gages. For each of the resulting 428 storms, the 93 gage depths are interpolated onto a dense grid and the resulting random field is anlyzed. Presented are: storm depth isohyets at 2 mm contour intervals, first three moments of point storm depth, spatial correlation function, spatial variance function, and the spatial distribution of total rainstorm depth.

High-frequency in situ optical measurements during a storm event: Assessing relationships between dissolved organic matter, sediment concentrations, and hydrologic processes

USGS Publications Warehouse

Saraceno, John F.; Pellerin, Brian A.; Downing, Bryan D.; Boss, Emmanuel; Bachand, Philip A. M.; Bergamaschi, Brian A.

2009-01-01

Dissolved organic matter (DOM) dynamics during storm events has received considerable attention in forested watersheds, but the extent to which storms impart rapid changes in DOM concentration and composition in highly disturbed agricultural watersheds remains poorly understood. In this study, we used identical in situ optical sensors for DOM fluorescence (FDOM) with and without filtration to continuously evaluate surface water DOM dynamics in a 415 km2agricultural watershed over a 4 week period containing a short-duration rainfall event. Peak turbidity preceded peak discharge by 4 h and increased by over 2 orders of magnitude, while the peak filtered FDOM lagged behind peak turbidity by 15 h. FDOM values reported using the filtered in situ fluorometer increased nearly fourfold and were highly correlated with dissolved organic carbon (DOC) concentrations (r2 = 0.97), providing a highly resolved proxy for DOC throughout the study period. Discrete optical properties including specific UV absorbance (SUVA254), spectral slope (S290–350), and fluorescence index (FI) were also strongly correlated with in situ FDOM and indicate a shift toward aromatic, high molecular weight DOM from terrestrially derived sources during the storm. The lag of the peak in FDOM behind peak discharge presumably reflects the draining of watershed soils from natural and agricultural landscapes. Field and experimental evidence showed that unfiltered FDOM measurements underestimated filtered FDOM concentrations by up to ∼60% at particle concentrations typical of many riverine systems during hydrologic events. Together, laboratory and in situ data provide insights into the timing and magnitude of changes in DOM quantity and quality during storm events in an agricultural watershed, and indicate the need for sample filtration in systems with moderate to high suspended sediment loads.

Decoupling of stream and vegetation solutes during the late stages of weathering: insights from elemental and Mg isotope trends at the Luquillo Critical Zone Observatory, Puerto Rico

NASA Astrophysics Data System (ADS)

Chapela Lara, M.; Schuessler, J. A.; Buss, H. L.; McDowell, W. H.

2017-12-01

During the evolution of the critical zone, the predominant source of nutrients to the vegetation changes from bedrock weathering to atmospheric inputs and biological recycling. In parallel, the architecture of the critical zone changes with time, promoting a change in water flow regime from near-surface porous flow during early weathering stages to more complex flow regimes modulated by clay-rich regolith during the late stages of weathering. As a consequence of these two concurrent processes, we can expect the predominant sources and pathways of solutes to the streams to also change during critical zone evolution. If this is true, we would observe a decoupling between the solutes used by the vegetation and those that determine the composition of the streams during the late stages of weathering, represented by geomorphically stable tropical settings. To test these hypotheses, we are analyzing the elemental and Mg isotopic composition of regolith and streams at the humid tropical Luquillo Critical Zone Observatory. We aim to trace the relative contributions of the surficial, biologically mediated pathways and the deeper, weathering controlled nutrient pathways. We also investigate the role of lithology on the solute decoupling between the vegetation and the stream, by examining two similar headwater catchments draining two different bedrocks (andesitic volcaniclastic and granitic). Our preliminary elemental and Mg isotope results are consistent with atmospheric inputs in the upper 2 m of regolith in both lithologies and with bedrock weathering at depth. During a short storm event ( 6 h), a headwater stream draining volcaniclastic bedrock showed a large variation in Mg and δ26Mg, correlated with total suspended solids, while another similar headwater granitic stream showed a much narrower variation. A larger stream draining volcaniclastic bedrock showed changes in Mg concentration in response to rain during the same storm event, but did not change in δ26Mg, suggesting the surficial-deep decoupling of solutes we observe in regolith profiles and headwater catchments might be overwhelmed by storage effects at increasing water residence times.

Classifying hydrological events to quantify their impact on nitrate leaching across three spatial scales

NASA Astrophysics Data System (ADS)

Bauwe, Andreas; Tiemeyer, Bärbel; Kahle, Petra; Lennartz, Bernd

2015-12-01

Nitrate is one of the most important sources of pollution for surface waters in tile-drained agricultural areas. In order to develop appropriate management strategies to reduce nitrate losses, it is crucial to first understand the underlying hydrological processes. In this study, we used Principle Component Analysis (PCA) and Linear Discriminant Analysis (LDA) to analyze 212 discharge events between 2004 and 2011 across three spatial scales (68 events at the collector drain, 72 at the ditch, and 72 at the brook) to identify the controlling factors for hydrograph response characteristics and their influence on nitrate concentration patterns. Our results showed that the 212 hydrological events can be classified into six different types: summer events (28%), snow-dominated events (10%), events controlled by rainfall duration (16%), rainfall totals (8%), dry antecedent conditions (10%), and events controlled by wet antecedent conditions (14%). The relatively large number of unclassified events (15%) demonstrated the difficulty in separating event types due to mutually influencing variables. NO3-N concentrations showed a remarkably consistent pattern during the discharge events regardless of event type, with minima at the beginning, increasing concentrations at the rising limb, and maxima around peak discharge. However, the level of NO3-N concentrations varied notably among the event types. The highest average NO3-N concentrations were found for events controlled by rainfall totals (NO3-N = 17.1 mg/l), events controlled by wet antecedent conditions (NO3-N = 17.1 mg/l), and snowmelt (NO3-N = 15.2 mg/l). Average maximum NO3-N concentrations were significantly lower during summer events (NO3-N = 10.2 mg/l) and events controlled by dry antecedent conditions (NO3-N = 11.7 mg/l). The results have furthermore shown that similar hydrological and biogeochemical processes determine the hydrograph and NO3-N response on storm events at various spatial scales. The management of tile-drained agricultural land to reduce NO3-N losses should focus explicitly on flow events and, more specifically, active management should preferably be conducted in the winter season for discharge events after snowmelt, after heavy rain storms and when the soil moisture conditions are wet.

Impacts of Land-applied Wastes from Concentrated Animal Feeding Operations on Aquatic Organisms

EPA Science Inventory

Midwest agricultural fields typically have subsurface tile-drain networks that facilitate transport of excess water from fields to a ditch network system, which can contain sediments, nutrients and pesticides as well as hormones from fields fertilized with manure and associated l...

Linking selenium sources to ecosystems: San Francisco Bay-Delta Model

USGS Publications Warehouse

Presser, Theresa S.; Luoma, Samuel N.

2004-01-01

Marine sedimentary rocks of the Coast Ranges contribute selenium to soil, surface water, and ground water in the western San Joaquin Valley, California. Irrigation funnels selenium into a network of subsurface drains and canals. Proposals to build a master drain (i.e., San Luis Drain) to discharge into the San Francisco Bay-Delta Estuary remain as controversial today as they were in the 1950s, when drainage outside the San Joaquin Valley was first considered. An existing 85-mile portion of the San Luis Drain was closed in 1986 after fish mortality and deformities in ducks, grebes and coots were discovered at Kesterson National Wildlife Refuge, the temporary terminus of the drain. A 28-mile portion of the drain now conveys drainage from 100,000 acres into the San Joaquin River and eventually into the Bay-Delta. If the San Luis Drain is extended directly to the Bay-Delta, as is now being proposed as an alternative to sustain agriculture, it could receive drainage from an estimated one-million acres of farmland affected by rising water tables and increasing salinity. In addition to agricultural sources, oil refineries also discharge selenium to the Bay-Delta, although those discharges have declined in recent years. To understand the effects of changing selenium inputs, scientists have developed the Bay-Delta Selenium Model.

Nutrient Flux from Mediterranean Coastal Streams: Carpinteria Valley, California

NASA Astrophysics Data System (ADS)

Robinson, T. H.; Leydecker, A.; Melack, J. M.; Keller, A. A.

2003-12-01

Along the southern California coast, near Santa Barbara, California, we are measuring nutrient export from specific land uses and developing a model to predict nutrient export at a watershed scale. The area is characterized by a Mediterranean-like climate and short steep catchments producing flashy runoff. The six land uses include chaparral, avocado orchards, greenhouse agriculture, open-field nurseries, and residential and commercial development. Sampling sites are located on defined drainages or storm drains that collect runoff from relatively homogeneous areas representing each land use. Stream water samples are taken once a week during the rainy season, every two weeks during the dry season and every one to four hours during storms. Samples are analyzed for ammonium, nitrate, phosphate, total dissolved nitrogen and particulate nitrogen and phosphorus. Intensive sampling at the thirteen sites of the study was conducted throughout Water Year (WY) 2002 and 2003. We determine discharge from measurements of stage derived from pressure transducers at all sampling sites. This information is then converted to flux at a high temporal resolution. Wet and dry season sampling has shown that nitrate baseflow concentrations vary over three orders of magnitude, from a few micromoles per liter in undeveloped catchments, to a few 100 æmol/L in agricultural and urban watersheds, to 1000 æmol/L where intensive "greenhouse" agriculture dominates. Nitrate loading ranged from a few moles per hectare per storm at undeveloped and residential sites to hundreds at the greenhouse site. Phosphate concentrations show a similar, but smaller, variation from 1 to 100 æmol/L, although the loading is comparable at 1-100 moles/ha-storm. Stormflow concentrations fluctuate with the storm hydrograph: phosphate increases with flow, while nitrate typically decreases due to dilution from runoff probably from impervious surfaces. Nitrate export patterns indicate a marked difference between land use type (1, 10, 100 g ha-1mm-1 for undisturbed, urban, and greenhouse sites respectively) and show little variance storm to storm during WY2002 and WY2003. The phosphate export pattern with successive storms is not as clear. Cumulative rainfall and/or runoff/rainfall ratios for nitrate and phosphate show promise as variables to simulate the magnitude of nutrient export for individual storms in non-monitored catchments.

Bayes Node Energy Polynomial Distribution to Improve Routing in Wireless Sensor Network

PubMed Central

Palanisamy, Thirumoorthy; Krishnasamy, Karthikeyan N.

2015-01-01

Wireless Sensor Network monitor and control the physical world via large number of small, low-priced sensor nodes. Existing method on Wireless Sensor Network (WSN) presented sensed data communication through continuous data collection resulting in higher delay and energy consumption. To conquer the routing issue and reduce energy drain rate, Bayes Node Energy and Polynomial Distribution (BNEPD) technique is introduced with energy aware routing in the wireless sensor network. The Bayes Node Energy Distribution initially distributes the sensor nodes that detect an object of similar event (i.e., temperature, pressure, flow) into specific regions with the application of Bayes rule. The object detection of similar events is accomplished based on the bayes probabilities and is sent to the sink node resulting in minimizing the energy consumption. Next, the Polynomial Regression Function is applied to the target object of similar events considered for different sensors are combined. They are based on the minimum and maximum value of object events and are transferred to the sink node. Finally, the Poly Distribute algorithm effectively distributes the sensor nodes. The energy efficient routing path for each sensor nodes are created by data aggregation at the sink based on polynomial regression function which reduces the energy drain rate with minimum communication overhead. Experimental performance is evaluated using Dodgers Loop Sensor Data Set from UCI repository. Simulation results show that the proposed distribution algorithm significantly reduce the node energy drain rate and ensure fairness among different users reducing the communication overhead. PMID:26426701

Bayes Node Energy Polynomial Distribution to Improve Routing in Wireless Sensor Network.

PubMed

Palanisamy, Thirumoorthy; Krishnasamy, Karthikeyan N

2015-01-01

Wireless Sensor Network monitor and control the physical world via large number of small, low-priced sensor nodes. Existing method on Wireless Sensor Network (WSN) presented sensed data communication through continuous data collection resulting in higher delay and energy consumption. To conquer the routing issue and reduce energy drain rate, Bayes Node Energy and Polynomial Distribution (BNEPD) technique is introduced with energy aware routing in the wireless sensor network. The Bayes Node Energy Distribution initially distributes the sensor nodes that detect an object of similar event (i.e., temperature, pressure, flow) into specific regions with the application of Bayes rule. The object detection of similar events is accomplished based on the bayes probabilities and is sent to the sink node resulting in minimizing the energy consumption. Next, the Polynomial Regression Function is applied to the target object of similar events considered for different sensors are combined. They are based on the minimum and maximum value of object events and are transferred to the sink node. Finally, the Poly Distribute algorithm effectively distributes the sensor nodes. The energy efficient routing path for each sensor nodes are created by data aggregation at the sink based on polynomial regression function which reduces the energy drain rate with minimum communication overhead. Experimental performance is evaluated using Dodgers Loop Sensor Data Set from UCI repository. Simulation results show that the proposed distribution algorithm significantly reduce the node energy drain rate and ensure fairness among different users reducing the communication overhead.

Revisiting Horton's laws with considerations of the directly drained VS source area

NASA Astrophysics Data System (ADS)

Yang, Soohyun; Paik, Kyungrock

2015-04-01

River networks have been regarded as excellent examples of self-similar patterns in nature. Fractal characteristics of river networks have been quantified through scaling relations between several morphologic variables (e.g., Hack, 1957; Flint, 1974). In particular, Horton's legendary study on scaling properties between numbers and lengths of streams in different orders (Horton, 1945) has significantly influenced research studies in this subject. Today, Horton's laws are referred to the log-linear relationships of three variables across stream orders, i.e., number, length, and area which is later added by Schumm (1956). In a closer look, there is a conceptual inconsistency between their definitions though. While length is defined as the length of stream of a specific order only, area by its definition includes drainage area of lower order streams. To deal with this inconsistency, there was an attempt to distinguish the average area drained directly by the stream of a particular order in the Hortonian formulation (Marani et al., 1991; Beer and Borgas, 1993). Nevertheless, there remains an interesting problem in the definition of directly drained area for 1st order and for the rest orders in these studies. While the whole area of 1st order stream is regarded as the directly drained area in these studies, for a channel to form it needs the minimum drainage area named source area. In this study, we evaluate how significant considering this zero order area separately is in understanding overall river network organization. To this end, we define new expression for the directly drained area and revisit Horton's laws with a generalized formulation. To test the proposed ideas, several river networks extracted from digital elevation models (DEMs) are analyzed. References Beer, T., & Borgas, M. (1993). Horton's laws and the fractal nature of streams. Water Resources Research, 29(5), 1475-1487. Flint, J. J. (1974). Stream gradient as a function of order, magnitude, and discharge. Water Resources Research, 10(5), 969-973. Hack, J. T. (1957). Studies of longitudinal river profiles in Virginia and Maryland. US, Geological Survey Professional Paper, 294. Horton, R. E. (1945). Erosional development of streams and their drainage basins; hydrophysical approach to quantitative morphology. Geological Society of America Bulletin, 56(3), 275-370. Marani, A., Rigon, R., & Rinaldo, A. (1991). A note on fractal channel networks. Water Resources Research, 27(12), 3041-3049. Schumm, S. A. (1956). Evolution of drainage systems and slopes in badlands at Perth Amboy, New Jersey. Geological Society of America Bulletin, 67(5), 597-646.

Stream Intermittency Sensors Monitor the Onset and Duration of Stream Flow Along a Channel Network During Storms

NASA Astrophysics Data System (ADS)

Jensen, C.; McGuire, K. J.

2017-12-01

Headwater streams are spatially extensive, accounting for a majority of global stream length, and supply downstream water bodies with water, sediment, organic matter, and pollutants. Much of this transmission occurs episodically during storms when stream flow and connectivity are high. Many headwaters are temporary streams that expand and contract in length in response to storms and seasonality. Understanding where and when streams carry flow is critical for conserving headwaters and protecting downstream water quality, but storm events are difficult to study in small catchments. The rise and fall of stream flow occurs rapidly in headwaters, making observation of the entire stream network difficult. Stream intermittency sensors that detect the presence or absence of water can reveal wetting and drying patterns over short time scales. We installed 50 intermittency sensors along the channel network of a small catchment (35 ha) in the Valley and Ridge of southwest Virginia. Previous work shows stream length is highly variable in this shale catchment, as the drainage density spans two orders of magnitude. The sensors record data every 15 minutes for one year to capture different seasons, antecedent moisture conditions, and precipitation rates. We seek to determine whether hysteresis between stream flow and network length occurs on the rising and falling limbs of events and if reach-scale characteristics such as valley width explain spatial patterns of flow duration. Our results indicate reaches with a wide, sediment-filled valley floor carry water for shorter periods of time than confined channel segments with steep valley side slopes. During earlier field mapping surveys, we only observed flow in a few of the tributaries for the wettest conditions mapped. The sensors now show that these tributaries flow more frequently during much smaller storms, but only for brief periods of time (< 1 hour). The high temporal sampling resolution of the sensors permits a more realistic estimate of flow duration in temporary streams, which field surveys may, otherwise, underestimate. Such continuous datasets on stream network length will allow researchers to more accurately assess the value of headwater reaches for contributions to environmental services such as aquatic habitat, hyporheic exchange, and mass fluxes of solutes.

Contributions of human activities to suspended sediment yield during storm events from a small, steep, tropical watershed

NASA Astrophysics Data System (ADS)

Messina, A. M.; Biggs, T. W.

2016-07-01

Suspended sediment concentrations (SSC) and yields (SSY) were measured during storm and non-storm periods from undisturbed and human-disturbed portions of a small (1.8 km2), mountainous watershed that drains to a sediment-stressed coral reef. Event-wise SSY (SSYEV) was calculated for 142 storms from measurements of water discharge (Q), turbidity (T), and SSC measured downstream of three key sediment sources: undisturbed forest, an aggregate quarry, and a village. SSC and SSYEV were significantly higher downstream of the quarry during both storm- and non-storm periods. The human-disturbed subwatershed (10.1% disturbed) accounted for an average of 87% of SSYEV from the watershed. Observed sediment yield (mass) to the coast, including human disturbed subwatersheds, was 3.9× the natural background. Specific SSY (mass/area) from the disturbed quarry area was 49× higher than from natural forest compared with 8× higher from the village area. Similar to mountainous watersheds in semi-arid and temperate climates, SSYEV from both the undisturbed and disturbed watersheds correlated closely with maximum event discharge (Qmax), event total precipitation and event total Q, but not with the Erosivity Index. Best estimates of annual SSY varied by method, from 45 to 143 tons/km2/yr from the undisturbed subwatershed, 441-598 tons/km2/yr from the human-disturbed subwatershed, and 241-368 tons/km2/yr from the total watershed. Sediment yield was very sensitive to disturbance; the quarry covers 1.1% of the total watershed area, but contributed 36% of SSYEV. Given the limited access to gravel for infrastructure development, sediment disturbance from local aggregate mining may be a critical sediment source on remote islands in the Pacific and elsewhere. Identification of erosion hotspots like the quarry using rapid, event-wise measures of suspended sediment yield will help efforts to mitigate sediment stress and restore coral reefs.

Influence of particulates on phosphorus loading exported from farm drainage during a storm event in the Everglades Agricultural Area

NASA Astrophysics Data System (ADS)

Bhadha, J. H.; Lang, T. A.; Daroub, S. H.

2015-12-01

The purpose of this study was to evaluate the influence of particulates on P loading captured during a single storm event. The Everglades Agricultural Area of Florida comprises 280,000 hectares of organic soil farmland artificially drained by ditches, canals and pumps. Phosphorus (P)-enriched suspended particulates in canals are susceptible to transport and can contribute significantly to the overall P loads in drainage water. A settling tank experiment was conducted to capture particulates during tropical storm Isaac in 2012 from three farms approximately 2.4 to 3.6 km2 in size. Farm canal discharge water was collected in a series of two 200 liter settling tanks over a seven-day drainage period, during tropical storm Isaac. Water from the settling tanks was siphoned through Imhoff settling cones, where the particulates were allowed to settle and collected for P-fractionation analyses, and compared to intact sediment cores collected from the bottom of the canals. The discharged particulates contained higher organic matter content (OM), total P, and labile P fractions compared to the canal bottom sediments. Based on the equilibrium P concentrations, surface sediments behave as a source of P to the water column. A seven-day continuous drainage event exported 4.7 to 11.1 metric tons of suspended solids per farm, corresponding to 32 to 63 kg of particulate P being lost to downstream ecosystems. Drainage associated to a single seven-day storm event exported up to 61% of the total annual farm P load. It is evident from this study that short-term, high-intensity storm events can skew annual P loads due to the export of significantly higher particulate matter from farm canals. Exported particulates rich in P can provide a supplemental source of nutrients if captured and replenished back into the farmlands, as a sustainable farming practice.

Los Angeles Area Permit Holder Estimated Trash Load Reduction

EPA Pesticide Factsheets

The Los Angeles River has been designated as an impaired waterbody due to the large volume of trash it receives from the watershed. To address this problem a Total Maximum Daily Load (TMDL), which establishes baseline trash loads to the river from the watershed, has been incorporated into the area stormwater permit. The permit requires each permittee to implement trash reduction measures for discharges through the storm drain system with an emphasis on the installation of full capture devices. The stormwater permit incorporates progressive reductions in trash discharges to the Los Angeles River, reaching a zero level in 2016.

Water quality and sources of fecal coliform bacteria in the Meduxnekeag River, Houlton, Maine

USGS Publications Warehouse

Culbertson, Charles W.; Huntington, Thomas G.; Stoeckel, Donald M.; Caldwell, James M.; O'Donnell, Cara

2014-01-01

In response to bacterial contamination in the Meduxnekeag River and the desire to manage the watershed to reduce contaminant sources, the Houlton Band of Maliseet Indians (HBMI) and the U.S. Geological Survey began a cooperative effort to establish a baseline of water-quality data that can be used in future studies and to indicate potential sources of nutrient and bacterial contamination. This study was conducted during the summer of 2005 in the Meduxnekeag River Basin near Houlton, Maine. Continuously recorded specific conductance can be a good indicator for water quality. Specific conductance increased downstream from the town of Houlton, between runoff events, and decreased sharply following major runoff events. Collections of discrete samples during the summer of 2005 indicated seasonal positive concentration-discharge relations for total phosphorus and total nitrogen; these results indicate that storm runoff may mobilize and transport these nutrients from the terrestrial environment to the river. Data collected by the HBMI on fecal coliform bacteria indicated that bacterial contamination enters the Meduxnekeag River from multiple paths including tributaries and surface drains (ditches) in developed areas in Houlton, Maine. The Houlton wastewater treatment discharge was not an important source of bacterial contamination. Bacteroidales-based tests for general fecal contamination (Bac32 marker) were predominantly positive in samples that had excessive fecal contamination as indicated by Enterococci density greater than 104 colony-forming units per 100 millilters. Of the 22 samples tested for Bacteroidales-based markers of human-associated fecal contamination (HF134 and HF183), 8 were positive. Of the 22 samples tested for Bacteroidales-based markers of ruminant-associated fecal contamination (CF128 and CF193), 7 were positive. Human fecal contamination was detected consistently at two sites (surface drains in urban areas in the town of Houlton) and occasionally detected at one site (Moose Brook) but was not detected at other sites. Fecal contamination (as indicated by fecal coliform density) apparently is localized under normal flow conditions with the highest levels restricted to drains in urban areas and to a lesser extent B Stream, Pearce Brook, and Big Brook, all tributaries to the main stem of the Meduxnekeag River. Coliphage were enumerated as an alternate indicator of fecal contamination with the intent of typing the virus into host-associated classes (human or ruminant), as was done for Enterococci; however, insufficient coliphage were isolated to provide more than preliminary indications. In spite of low coliphage enumeration, the preliminary results strengthen the conclusion that the Enterococci data correctly indicated the samples that contained human and ruminant fecal contamination. The finding that contamination was in many of the tributaries following storms in mid-July indicates that storm runoff likely carries fecal contaminants to more locations than runoff under lower flow conditions.

Preliminary results from a study of natural slope failures triggered by the storm of November 3.5.1985, Germany Valley, West Virginia and Virginia: Chapter 4 in Landslides of eastern North America

USGS Publications Warehouse

Jacobson, Robert B.; Cron, Elizabeth D.; McGeehin, John P.

1987-01-01

During the first five days of November 1985, a low-pressure system in the Ohio River valley combined with a low-pressure system referred to as Tropical Storm Juan to produce heavy rainfall in the Potomac, James, and Rappahannock River basins. Severe flooding accompanied the rainfall; 43 lives were lost and the flood was estimated to be the most expensive natural disaster of 1985 in the United States (Scatena, 1986). The rainfall also triggered many slope failures. An especially large concentration of slope failures was associated with an area of moderate rainfall centered in the Germany Valley in Pendleton County, West Virginia (fig. 4.1A ). This report describes some preliminary results from our continuing research into the geological and meteorological controls on the distributions of slope failures in the Germany Valley area. The Germany Valley is the first major anticlinal valley in the Valley and Ridge province east of the Allegheny structural front (Diecchio, 1986). Our interest is focused on the portion from near Mouth of Seneca, West Virginia, in the Onego 7 .5-minute quadrangle, to near Mill Gap, Virginia, in the Mustoe 7.5-minute quadrangle (patterned in figs. 4.1 and 4.2). This area was a natural experiment for studying the effects of the storm because rainfall varied systematically from southwest to northeast along the valley, while bedrock lithology and structure are nearly constant. Furthermore, variation of rock types across the valley allows comparisons among lithologies at given levels of precipitation. The valley is floored by Ordovician carbonates of the Trenton, Black River, and St. Paul Groups and shales of the Martinsburg (Reedsville) Shale. The ridges are formed by sandstones of the Tuscarora and Oswego Sandstones, and the Juniata formation. The southwestern quarter of the valley is drained by Back Creek of the James River basin, and the remainder of the valley drains north and west to the North Fprk of the South Branch Potomac River.

Exploring storage and runoff generation processes for urban flooding through a physically based watershed model

NASA Astrophysics Data System (ADS)

Smith, B. K.; Smith, J. A.; Baeck, M. L.; Miller, A. J.

2015-03-01

A physically based model of the 14 km2 Dead Run watershed in Baltimore County, MD was created to test the impacts of detention basin storage and soil storage on the hydrologic response of a small urban watershed during flood events. The Dead Run model was created using the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) algorithms and validated using U.S. Geological Survey stream gaging observations for the Dead Run watershed and 5 subbasins over the largest 21 warm season flood events during 2008-2012. Removal of the model detention basins resulted in a median peak discharge increase of 11% and a detention efficiency of 0.5, which was defined as the percent decrease in peak discharge divided by percent detention controlled area. Detention efficiencies generally decreased with increasing basin size. We tested the efficiency of detention basin networks by focusing on the "drainage network order," akin to the stream order but including storm drains, streams, and culverts. The detention efficiency increased dramatically between first-order detention and second-order detention but was similar for second and third-order detention scenarios. Removal of the soil compacted layer, a common feature in urban soils, resulted in a 7% decrease in flood peak discharges. This decrease was statistically similar to the flood peak decrease caused by existing detention. Current soil storage within the Dead Run watershed decreased flood peak discharges by a median of 60%. Numerical experiment results suggested that detention basin storage and increased soil storage have the potential to substantially decrease flood peak discharges.

Impact of a medical waste incinerator on mercury levels in lagoon fish from a small tropical island in the Western Pacific.

PubMed

Denton, Gary R W; Trianni, Michael S; Bearden, Brian G; Houk, Peter C; Starmer, John A

2011-01-01

In 2004-2005, several species of marine fish were collected for mercury (Hg) analysis from Saipan Lagoon, Saipan, Commonwealth of the Northern Mariana Islands. Relatively high concentrations were found in representatives from the Hafa Adai Beach area located some distance from known sources of Hg contamination. A follow-up investigation aimed at identifying additional land-based sources of Hg in the area was launched in early 2007. The study identified a medical waste incinerator as the primary source of Hg enrichment. The incinerator was operational for about 20 years before it was closed down by the U.S. Environmental Protection Agency (EPA) in January 2006, for multiple violations of the Clean Air Act. Stormwater runoff from this facility entered a drainage network that discharged into the ocean at the southern end of Hafa Adai Beach, about 1 km away. At the time of this investigation storm drain sediments at the coast were only marginally enriched with mercury although values some 50x above background were detected in drainage deposits a few meters down-gradient of the incinerator site. Mercury concentrations in fish from the Hafa Adai Beach area were also significantly lower than those determined in similar species 3 yr earlier. The implications of the data are briefly discussed.

Leaching of additives from construction materials to urban storm water runoff.

PubMed

Burkhardt, M; Zuleeg, S; Vonbank, R; Schmid, P; Hean, S; Lamani, X; Bester, K; Boller, M

2011-01-01

Urban water management requires further clarification about pollutants in storm water. Little is known about the release of organic additives used in construction materials and the impact of these compounds to storm water runoff. We investigated sources and pathways of additives used in construction materials, i.e., biocides in facades' render as well as root protection products in bitumen membranes for rooftops. Under wet-weather conditions, the concentrations of diuron, terbutryn, carbendazim, irgarol 1051 (all from facades) and mecoprop in storm water and receiving water exceeded the predicted no-effect concentrations values and the Swiss water quality standard of 0.1 microg/L. Under laboratory conditions maximum concentrations of additives were in the range of a few milligrams and a few hundred micrograms per litre in runoff of facades and bitumen membranes. Runoff from aged materials shows approximately one to two orders of magnitude lower concentrations. Concentrations decreased also during individual runoff events. In storm water and receiving water the occurrence of additives did not follow the typical first flush model. This can be explained by the release lasting over the time of rainfall and the complexity of the drainage network. Beside the amounts used, the impact of construction materials containing hazardous additives on water quality is related clearly to the age of the buildings and the separated sewer network. The development of improved products regarding release of hazardous additives is the most efficient way of reducing the pollutant load from construction materials in storm water runoff.

Organochlorine pesticides in the Johnson Creek Basin, Oregon, 1988-2002

USGS Publications Warehouse

Tanner, Dwight Q.; Lee, Karl K.

2004-01-01

Organochlorine pesticides were detected in unfiltered samples from Johnson Creek that were collected during a storm in March, 2002. Total DDT (the sum of DDT and its metabolites), as well as dieldrin, potentially exceeded Oregon chronic, freshwater criteria at all four Johnson Creek stream-sampling sites. The total DDT criterion was also potentially exceeded at a storm drain at SE 45th Avenue and Umatilla Street. The concentration of total DDT in water samples has decreased by an order of magnitude since previous sampling was done on Johnson Creek in 1989?1990. This decrease was probably due to the movement of these compounds out of the basin and to degradation processes. Concentrations and loads of the organochlorine pesticides were largest at the most upstream sampling site, Johnson Creek at Palmblad Road, which has historically been primarily affected by agricultural land cover. Concentrations and loads were smaller at downstream locations, and there were only a few detections from storm drains. For the purposes of assessing trends in total DDT concentration in Johnson Creek, data for total suspended solids (TSS) were examined, because TSS is often correlated with DDT concentrations, and TSS data are collected routinely by regulatory agencies. As an intermediate step, linear regression was used to relate TSS (measured in the recent study) and turbidity (measured both in the earlier and in the recent studies). For 77 samples, TSS (in mg/L [milligrams per liter]) = 0.88 x Turbidity (in nephleometric turbidity units). The r2 value was 0.82. The TSS concentration (measured, or estimated by the regression) was compared to the concentration of total DDT using linear regression. The TSS concentration associated with meeting the Oregon water-quality criterion for total DDT was 15 to 18 mg/L in the lower and middle part of the basin and 8 mg/L in the upper reaches of the basin. This TSS/DDT relationship is based on only one storm and may not be valid for other conditions of streamflow and runoff. Dieldrin concentration was not well correlated with TSS. Organochlorine compounds also were detected in significant concentrations in Kelley Creek, an important tributary to Johnson Creek, but quality-control considerations made it difficult to interpret some of the data. It does appear, however, that some of the metabolites of DDT were positively associated with TSS. The high concentrations of the DDT metabolites and dieldrin were correlated with agricultural areas.

Doppler Radar and Lightning Network Observations of a Severe Outbreak of Tropical Cyclone Tornadoes

NASA Technical Reports Server (NTRS)

McCaul, Eugene W., Jr.; Buechler, Dennis; Goodman, Steven; Cammarata, Michael

2003-01-01

Data from a single WSR-88D Doppler radar and the National Lightning Detection Network are used to examine in detail the characteristics of the convective storms that produced a severe tornado outbreak within Tropical Storm Beryl's remnants on 16 August 1994. Comparison of the radar data with reports of tornadoes suggests that only 13 cells produced the 29 tornadoes that were documented in Georgia and the Carolinas on that date. Six of these cells spawned multiple tornadoes, and the radar data confirm the presence of miniature supercells. One of the cells was identifiable on radar for 11 hours, spawning tornadoes over a time period spanning approximately 6.5 hours. Several other tornadic cells also exhibited great longevity, with cell lifetimes greater than ever previously documented in a landfalling tropical cyclone tornado event, and comparable to those found in major midlatitude tornadic supercell outbreaks. Time-height analyses of the three strongest tornadic supercells are presented in order to document storm kinematic structure and to show how these storms appear at different ranges from a WSR-88D radar. In addition, cloud-to-ground (CG) lightning data are examined for the outbreak, the most intense tropical cyclone tornado event studied thus far. Although the tornadic cells were responsible for most of Beryl's CG lightning, flash rates were only weak to moderate, even in the most intense supercells, and in all the tornadic storms the lightning flashes were almost entirely negative in polarity. A few of the single-tornado storms produced no detectable CG lightning at all. In the stronger cells, there is some evidence that CG lightning rates decreased during tornadogenesis, as has been documented before in some midlatitude tornadic storms. A number of the storms spawned tornadoes just after producing their final CG lightning flashes. Surprisingly, both peak currents and positive flash percentages were larger in Beryl s nontornadic storms than in the tornadic ones. Despite some intriguing patterns, the CG lightning behavior in this outbreak remains mostly inconsistent and ambiguous, and offers only secondary value for warning guidance. The present findings argue in favor of the implementation of observing systems capable of continuous monitoring of total lightning activity in storms.

Mesoscale aspects of jet streak coupling and implications for the short term forecasting of severe convective storms. [severe environmental storms and mesoscale experiment (SESAME)

NASA Technical Reports Server (NTRS)

Uccellini, L. W.; Kocin, P. J.

1981-01-01

An analysis of a tornado outbreak in Wichita Falls, Texas was analyzed. The coupling of upper and lower tropospheric jet streaks, leading to severe storm outbreaks is illustrated. The high resolution SESAME data sets indicate that mass and momentum adjustments which couple upper and lower tropospheric jets occur within a 3 to 6 hr time frame over a 100 to 500 km domain, and establish the role of isallobaric forcing in the storm development. It is suggested that the output rate of data from the existing 12 hr network be increased to provide better temporal resolution of wind, mass and moisture data.

Appraisal of operating efficiency of recharge basins on Long Island, New York, in 1969

USGS Publications Warehouse

Aronson, D.A.; Seaburn, G.E.

1974-01-01

Recharge basins on Long Island are unlined pits of various shapes and sizes excavated in surficial deposits of mainly glacial origin. Of the 2,124 recharge basins on Long Island in 1969, approximately 9 percent (194) contain water 5 or more days after a 1-inch rainfall. Basins on Long Island contain water because (1) they intersect the regional water table or a perched water table, (2) they are excavated in material of low hydraulic conductivity, (3) layers of sediment and debris of low hydraulic conductivity accumulate on the basin floor, or (4) a combination of these factors exists. Data obtained as part of this study show that (1) 22 basins contain water because they intersect the regional water table, (2) a larger percentage of the basins excavated in the Harbor Hill and the Ronkonkoma morainal deposits contain water than basins excavated in the outwash deposits, (3) a larger percentage of the basins that drain industrial and commercial areas contain water than basins that drain highways and residential areas, (4) storm runoff from commercial and industrial areas and highway: generally contains high concentrations of asphalt, grease, oil, tar, and rubber particles, whereas runoff from residential areas mainly contains leaves, grass cuttings, and other plant material, and (5) differences in composition of the soils within the drainage areas of the basins on Long Island apparently are not major factors in causing water retention. Water-containing basins dispose of an undetermined amount of storm runoff primarily by the slow infiltration of water through the bottoms and the sides of the basins. The low average specific conductance of water in most such basins suggests that evaporation does not significantly concentrate the chemical constituents and, therefore, that evaporation is not a major mechanism of water disposal from these basins.

Public health assessment for George Air Force Base, Victorville, San Bernardino County, California, Region 9: CERCLIS Number CA2570024453. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-12-01

George Air Force Base (AFB) is located in Victorville, California, in the Mojave Desert approximately 90 miles northeast of Los Angeles. Areas of concern at George AFB are divided into three operable units (OUs): Groundwater in the northeast portion of the base and adjacent off-site land is contaminated with volatile organic compounds, primarily TCE. A groundwater extraction and treatment system, designed to prevent migration of the contaminant plume towards the Mojave River, was completed in 1997. OU 1 also includes two other sites: SD-25, an industrial/storm drain, and WP-26, the former sewage treatment plant percolation ponds. Contaminated sediments and pipingmore » were removed from the storm drain at SD-25. A variety of leaks in this system resulted in an estimated of perhaps as much as a 750,000 to 800,000-gallon plume of jet propellant no. 4 (JP-4) encompassing an area of over 31 acres, as well as a dissolved-phase plume of benzene, toluene, ethylbenzene, and xylenes extending over an area of 121 acres. Because of OU2 plumes is almost completely covered by asphalt, and studies conducted thus far have not demonstrated significant migration of the plume, George AFB, state and federal regulators continue to evaluate the feasibility of natural attenuation as a possible cleanup strategy. This OU consists of the remaining Installation Restoration Program sites, includes old landfills, other dump and burial sites, munitions sites, fire training areas, and spill areas. In February 1997, George AFB completed a remedial investigation/feasibility study for OU 3.« less

Identification of pollutant sources in a rapidly developing urban river catchment in China

NASA Astrophysics Data System (ADS)

Huang, Jingshui; Yin, Hailong; Jomma, Seifeddine; Rode, Michael; Zhou, Qi

2016-04-01

Rapid economic development and urbanization worldwide cause serious ecological and environmental problems. A typical region that is in transition and requires systemic research for effective intervention is the rapidly developing city of Hefei in central P. R. China. In order to investigate the sources of pollutants over a one-year period in Nanfei River catchment that drains the city of Hefei, discharges were measured and water samples were taken and measured along the 14km river section at 10 sites for 4 times from 2013 to 2014. Overflow concentrations of combined sewer and separate storm drains were also measured by selecting 15 rain events in 4 typical drainage systems. Loads and budgets of water and different pollutant sources i.e., wastewater treatment plant (WWTP) effluent, urban drainage overflow, unknown wastewater were calculated. The water balance demonstrated that >70% of the discharge originated from WWTP effluent. Lack of clean upstream inflow thereby is threatening ecological safety and water quality. Furthermore, mass fluxes calculations revealed that >40% of the COD (Chemical Oxygen Demand) loads were from urban drainage overflow because of a large amount of discharge of untreated wastewater in pumping stations during rain events. WWTP effluent was the predominant source of the total nitrogen loads (>60%) and ammonia loads (>45%). However, the total phosphorous loads from three different sources are similar (˜1/3). Thus, our research provided a basis for appropriate and prior mitigation strategies (state-of-art of WWTP upgrade, sewer systems modification, storm water regulation and storage capacity improvement, etc.) for different precedence-controlled pollutants with the limited infrastructure investments in these rapidly developing urban regions.

Temporal Dynamics in the Concentration, Flux, and Optical Properties of Tree-Derived Dissolved Organic Matter in an Epiphyte-Laden Oak-Cedar Forest

NASA Astrophysics Data System (ADS)

Van Stan, John T.; Wagner, Sasha; Guillemette, François; Whitetree, Ansley; Lewis, Julius; Silva, Leticia; Stubbins, Aron

2017-11-01

Studies on the fate and transport of dissolved organic matter (DOM) along the rainfall-to-discharge flow pathway typically begin in streams or soils, neglecting the initial enrichment of rainfall with DOM during contact with plant canopies. However, rain water can gather significant amounts of tree-derived DOM (tree-DOM) when it drains from the canopy, as throughfall, and down the stem, as stemflow. We examined the temporal variability of event-scale tree-DOM concentrations, yield, and optical (light absorbance and fluorescence) characteristics from an epiphyte-laden Quercus virginiana-Juniperus virginiana forest on Skidaway Island, Savannah, Georgia (USA). All tree-DOM fluxes were highly enriched in dissolved organic carbon (DOC) compared to rainfall, and epiphytes further increased concentrations. Stemflow DOC concentrations were greater than throughfall across study species, yet larger throughfall water yields produced greater DOC yields versus stemflow. Tree-DOM optical characteristics indicate it is aromatic-rich with fluorescent DOM dominated by humic-like fluorescence, containing 10-20% protein-like (tryptophan-like) fluorescence. Storm size was the only storm condition that strongly correlated with tree-DOM concentration and flux; however, throughfall and stemflow optical characteristics varied little across a wide range of storm conditions (from low magnitude events to intense tropical storms). Annual tree-DOM yields from the study forest (0.8-46 g C m-2 yr-1) were similar to other yields from discrete down-gradient fluxes (litter leachates, soil leachates, and stream discharge) along the rainfall-to-discharge flow path.

Designsafe-Ci a Cyberinfrastructure for Natural Hazard Simulation and Data

NASA Astrophysics Data System (ADS)

Dawson, C.; Rathje, E.; Stanzione, D.; Padgett, J.; Pinelli, J. P.

2017-12-01

DesignSafe is the web-based research platform of the Natural Hazards Engineering Research Infrastructure (NHERI) network that provides the computational tools needed to manage and analyze critical data for natural hazards research, with wind and storm surge related hazards being a primary focus. One of the simulation tools under DesignSafe is the Advanced Circulation (ADCIRC) model, a coastal ocean model used in storm surge analysis. ADCIRC is an unstructured, finite element model with high resolution capabilities for studying storm surge impacts, and has long been used in storm surge hind-casting and forecasting. In this talk, we will demonstrate the use of ADCIRC within the DesignSafe platform and its use for forecasting Hurricane Harvey. We will also demonstrate how to analyze, visualize and archive critical storm surge related data within DesignSafe.

Carbon nanotube network thin-film transistors on flexible/stretchable substrates

DOEpatents

Takei, Kuniharu; Takahashi, Toshitake; Javey, Ali

2016-03-29

This disclosure provides systems, methods, and apparatus for flexible thin-film transistors. In one aspect, a device includes a polymer substrate, a gate electrode disposed on the polymer substrate, a dielectric layer disposed on the gate electrode and on exposed portions of the polymer substrate, a carbon nanotube network disposed on the dielectric layer, and a source electrode and a drain electrode disposed on the carbon nanotube network.

Bagley Fire Sediment Study: Shasta-Trinity National Forest, Eastern Klamath Mountains, Northern California

NASA Astrophysics Data System (ADS)

Bachmann, S.; De La Fuente, J. A.; Hill, B.; Mai, C.; Mikulovsky, R. P.; Mondry, Z.; Rust, B.; Young, D.

2013-12-01

The US Forest Service is conducting a study of sediment mobilization, transport, and deposition on the Bagley Fire, which burned about 18,000 hectares in late summer, 2012, on the Shasta-Trinity National Forest, south of McCloud, CA. The fire area is in steep terrain of the Eastern Klamath Mountains that are underlain primarily by metasedimentary rock. The watersheds affected drain into the headwaters of Squaw Creek, along with small streams tributary to the McCloud and Pit Rivers, all of which flow into Shasta Lake Reservoir. In November and December of 2012, intense storms occurred over the fire area with estimated return intervals of 25-50 years, based on 4-day storm totals in ranging from 38 to 56 cm. The Squaw Creek storm response was unique for this area, in that it remained turbid for about 2 months following the storms. Subsequent small storms through June, 2013 have also generated prolonged turbidity. This may be attributable to the remobilization of fine particles temporarily stored in the channel network. Preliminary observations from field reconnaissance include the following: a) Erosional processes were dominated by sheet, rill, and gully erosion, and the resulting sediment delivered to channels was rich in fine particles and gravels; b) Landslides were infrequent, and as a result, a limited amount of large rock and logs were delivered to channels; c) Sediment laden flows occurred in most burned low order channels, but classic debris flows, those scouring all vegetation from channel bottoms, were very uncommon; d) Most road stream crossing culverts failed in high severity burn areas; e) Low gradient stream reaches in Squaw Creek were aggraded with fine sediment; f) Sustained high levels of turbidity occurred in the main stem of Squaw Creek. The goals of this study are to characterize relative roles of surface erosion, landslides, and debris flows in delivering sediment to streams after the fire, and if possible, to develop a rough sediment budget, comparing the amount of sediment delivered to the reservoir to that mobilized on hillslopes and in channels. A combination of remote sensing and field methods are being used. Remote sensing methods include post-fire air photo interpretation and mapping, LiDAR data analysis, and reservoir bathymetry. Field methods include reconnaissance traverses, and transects for direct estimates of sediment volume from surface erosion, gullies, and landslides. Results of this study will improve our understanding of erosional and sedimentation processes in this specific post-wildfire response domain, including reservoir sedimentation rates. They will also provide land managers with sound information upon which to base future decisions on the management of the local natural resources. Lastly, they will facilitate the work of Burned Area Emergency Response teams (BAER) which respond to future wildfires in this domain, and promote development of better designs for road/stream crossings.

Water budgets, water quality, and analysis of nutrient loading of the Winter Park chain of lakes, central Florida, 1989-92

USGS Publications Warehouse

Phelps, G.G.; German, E.R.

1995-01-01

The Winter Park chain of lakes (Lakes Maitland, Virginia, Osceola, and Mizell) has a combined area of about 900 acres, an immediate drainage area of about 3,100 acres, and mean depths ranging from 11 to 15 feet. The lakes are an important recreational resource for the surrounding communities, but there is concern about the possible effects of stormwater runoff and seepage of nutrient-enriched ground water on the quality of water in the lakes. The lakes receive water from several sources: rainfall on lake surfaces, inflow from other surface-water bodies, stormflow that enters the lakes through storm drains or by direct runoff from land adjacent to the lakes and ground-water seepage. Water leaves the lakes by evaporation, surface outflow, and ground-water outflow. Of the three, only surface outflow can be measured directly. Rainfall, surface inflow and outflow, and lake-stage data were collected from October 1, 1989, to September 30, 1992. Stormflow, evaporation and ground-water inflow and outflow were estimated for the 3 years of the study. Ground-water outflow was calculated by evaluating the rate of lake-stage decline during dry periods. Estimated ground-water outflow was compared to downward leakage rates estimated by ground-water flow models. Lateral ground-water inflow from surficial sediments was calculated as the residual of the flow budget. Flow budgets were calculated for the 3 years of the study. In water year 1992 (a year with about average rainfall), inflow consisted of rainfall, 48 inches; stormflow, 15 inches; surface inflow, 67 inches; and ground water, 40 inches. The calculated outflows were evaporation, 47 inches; surface outflow, 90 inches; and ground water, 33 inches. Water-quality data also were used to calculate nutrient budgets for the lakes. Bimonthly water samples were collected from the lakes and at surface inflow and outflow sites, and were analyzed for physical characteristics, dissolved oxygen, pH, specific conductance, major ions, the nutrients nitrogen and phosphorus, and chlorophyll (collected at lake sites only). Specific conductance ranged from about 190 to 230 microsiemens per centimeter at 25 degrees Celsius in Lakes Maitland, Virginia and Osceola and from about 226 to 260 microsiemens per centimeter at 25 degrees Celsius in Lake Mizell. The median concentrations of total ammonia-plus-organic nitrogen in all the lakes ranged from 0.79 to 0.99 milligrams per liter. Median total phosphorus concentrations ranged from less than 0.02 to 0.20 milligrams per liter. Stormwater samples were collected for 17 storms at one storm-drain site and 16 storms at another storm-drain site on Lake Osceola. Median total nitrogen concentrations at the sites were 2.23 and 3.06 milligrams per liter and median total phosphorus concentrations were 0.34 and 0.40 milligrams per liter. The water quality in the Winter Park lakes generally is fair to good, based on a trophic-state index used by the Florida Department of Environmental Protection for assessing the tropic state of Florida lakes. This index was determined from median total nitrogen, total phosphorus, and chlorophyll-a concentrations, and median Secchi-disk transparency for all lakes for the period September 1989 to June 1992. Based on a one-time sampling of 20 sites around the lakes, surficial ground-water quality is highly variable. Nutrient concentrations were highly variable and could not be correlated to the proximity of septic tanks. Fertilizer probably is the primary source of nutrients in the surficial ground water. Nutrient budgets were calculated for the lakes for the 3 years of the study. The most variable source of nutrient loading to the lakes is stormwater. Nutrient-loading modeling indicates that reduction of nutrients in stormflow probably would improve lake-water quality. However, even with complete removal of nitrogen and phosphorus from stormwater, the lakes might still be mesotrophic with respect to both nutrients during periods of below ave

A Study of the Solar Wind-Magnetosphere Coupling Using Neural Networks

NASA Astrophysics Data System (ADS)

Wu, Jian-Guo; Lundstedt, Henrik

1996-12-01

The interaction between solar wind plasma and interplanetary magnetic field (IMF) and Earth's magnetosphere induces geomagnetic activity. Geomagnetic storms can cause many adverse effects on technical systems in space and on the Earth. It is therefore of great significance to accurately predict geomagnetic activity so as to minimize the amount of disruption to these operational systems and to allow them to work as efficiently as possible. Dynamic neural networks are powerful in modeling the dynamics encoded in time series of data. In this study, we use partially recurrent neural networks to study the solar wind-magnetosphere coupling by predicting geomagnetic storms (as measured by the Dstindex) from solar wind measurements. The solar wind, the IMF and the geomagnetic index Dst data are hourly averaged and read from the National Space Science Data Center's OMNI database. We selected these data from the period 1963 to 1992, which cover 10552h and contain storm time periods 9552h and quiet time periods 1000h. The data are then categorized into three data sets: a training set (6634h), across-validation set (1962h), and a test set (1956h). The validation set is used to determine where the training should be stopped whereas the test set is used for neural networks to get the generalization capability (the out-of-sample performance). Based on the correlation analysis between the Dst index and various solar wind parameters (including various combinations of solar wind parameters), the best coupling functions can be found from the out-of-sample performance of trained neural networks. The coupling functions found are then used to forecast geomagnetic storms one to several hours in advance. The comparisons are made on iterating the single-step prediction several times and on making a non iterated, direct prediction. Thus, we will present the best solar wind-magnetosphere coupling functions and the corresponding prediction results. Interesting Links: Lund Space Weather and AI Center

Doppler Radar and Lightning Network Observations of a Severe Outbreak of Tropical Cyclone Tornadoes

NASA Technical Reports Server (NTRS)

Mccaul, Eugene W., Jr.; Buechler, Dennis E.; Goodman, Steven J.; Cammarata, Michael

2004-01-01

Data from a single Weather Surveillance Radar-1988 Doppler (WSR-88D) and the National Lightning Detection Network are used to examine the characteristics of the convective storms that produced a severe tornado outbreak, including three tornadoes that reached F3 intensity, within Tropical Storm Beryl s remnants on 16 August 1994. Comparison of the radar data with reports of tornadoes suggests that only 13 cells produced the 29 tornadoes that were documented in Georgia and the Carolinas on that date. Six of these cells spawned multiple tornadoes, and the radar data confirm the presence of miniature supercells. One of the cells was identifiable on radar for 11 h. spawning tornadoes over a time period spanning approximately 6.5 h. Several other tornadic cells also exhibited great longevity, with cell lifetimes longer than ever previously documented in a landfalling tropical cyclone (TC) tornado event. This event is easily the most intense TC tornado outbreak yet documented with WSR-88Ds. Time-height analyses of the three strongest tornadic supercells are presented in order to document storm kinematic structure and to show how these storms appear at different ranges from a WSR-88D. In addition, cloud-to-ground (CG) lightning data are examined in Beryl s remnants. Although the tornadic cells were responsible for most of Beryl's CG lightning, their flash rates were only weak to moderate, and in all the tornadic storms the lightning flashes were almost entirely negative in polarity. A few of the single-tornado storms produced no detectable CG lightning at all. There is evidence that CG lightning rates decreased during the tornadoes, compared to 30-min periods before the tornadoes. A number of the storms spawned tornadoes just after producing their final CG lightning flashes. Contrary to the findings for flash rates, both peak currents and positive flash percentages were larger in Beryl's nontornadic storms than in the tornadic ones.

Using radar-derived parameters to forecast lightning cessation for nonisolated storms

NASA Astrophysics Data System (ADS)

Davey, Matthew J.; Fuelberg, Henry E.

2017-03-01

Lightning impacts operations at the Kennedy Space Center (KSC) and other outdoor venues leading to injuries, inconvenience, and detrimental economic impacts. This research focuses on cases of "nonisolated" lightning which we define as one cell whose flashes have ceased although it is still embedded in weak composite reflectivity (Z ≥ 15 dBZ) with another cell that is still producing flashes. The objective is to determine if any radar-derived parameters provide useful information about the occurrence of lightning cessation in remnant storms. The data set consists of 50 warm season (May-September) nonisolated storms near KSC during 2013. The research utilizes the National Lightning Detection Network, the second generation Lightning Detection and Ranging network, and polarized radar data. These data are merged and analyzed using the Warning Decision Support System-Integrated Information at 1 min intervals. Our approach only considers 62 parameters, most of which are related to the noninductive charging mechanism. They included the presence of graupel at various thermal altitudes, maximum reflectivity of the decaying storm at thermal altitudes, maximum connecting composite reflectivity between the decaying cell and active cell, minutes since the previous flash, and several others. Results showed that none of the parameters reliably indicated lightning cessation for even our restrictive definition of nonisolated storms. Additional research is needed before cessation can be determined operationally with the high degree of accuracy required for safety.

The impact of domestic rainwater harvesting systems in storm water runoff mitigation at the urban block scale.

PubMed

Palla, A; Gnecco, I; La Barbera, P

2017-04-15

In the framework of storm water management, Domestic Rainwater Harvesting (DRWH) systems are recently recognized as source control solutions according to LID principles. In order to assess the impact of these systems in storm water runoff control, a simple methodological approach is proposed. The hydrologic-hydraulic modelling is undertaken using EPA SWMM; the DRWH is implemented in the model by using a storage unit linked to the building water supply system and to the drainage network. The proposed methodology has been implemented for a residential urban block located in Genoa (Italy). Continuous simulations are performed by using the high-resolution rainfall data series for the ''do nothing'' and DRWH scenarios. The latter includes the installation of a DRWH system for each building of the urban block. Referring to the test site, the peak and volume reduction rate evaluated for the 2125 rainfall events are respectively equal to 33 and 26 percent, on average (with maximum values of 65 percent for peak and 51 percent for volume). In general, the adopted methodology indicates that the hydrologic performance of the storm water drainage network equipped with DRWH systems is noticeable even for the design storm event (T = 10 years) and the rainfall depth seems to affect the hydrologic performance at least when the total depth exceeds 20 mm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sinkhole flooding in Murfreesboro, Rutherford County, Tennessee, 2001-02

USGS Publications Warehouse

Bradley, Michael W.; Hileman, Gregg Edward

2006-01-01

The U.S. Geological Survey, in cooperation with the City of Murfreesboro, Tennessee, conducted an investigation from January 2001 through April 2002 to delineate sinkholes and sinkhole watersheds in the Murfreesboro area and to characterize the hydrologic response of sinkholes to major rainfall events. Terrain analysis was used to define sinkholes and delineate the sinkhole drainage areas. Flooding in 78 sinkholes in three focus areas was identified and tracked using aerial photography following three major storms in February 2001, January 2002, and March 2002. The three focus areas are located to the east, north, and northwest of Murfreesboro and are underlain primarily by the Ridley Limestone with some outcrops of the underlying Pierce Limestone. The observed sinkhole flooding is controlled by water inflow, water outflow, and the degree of the hydraulic connection (connectivity) to a ground-water conduit system. The observed sinkholes in the focus areas are grouped into three categories based on the sinkhole morphology and the connectivity to the ground-water system as indicated by their response to flooding. The three types of sinkholes described for these focus areas are pan sinkholes with low connectivity, deep sinkholes with high connectivity, and deep sinkholes with low connectivity to the ground-water conduit system. Shallow, broad pan sinkholes flood as water inflow from a storm inundates the depression at land surface. Water overflow from one pan sinkhole can flow downgradient and become inflow to a sinkhole at a lower altitude. Land-surface modifications that direct more water into a pan sinkhole could increase peak-flood altitudes and extend flood durations. Land-surface modifications that increase the outflow by overland drainage could decrease the flood durations. Road construction or alterations that reduce flow within or between pan sinkholes could result in increased flood durations. Flood levels and durations in the deeper sinkholes observed in the three focus areas are primarily affected by the connectivity with the ground-water conduit system. Deep sinkholes with a relatively high connectivity to the ground-water system fill quickly after a storm, and drain rapidly after the storm ends, and water levels decline as much as 3 to 5 feet per day in the first 2 to 3 days after a major storm. These sinkholes store the initial floodwater and then rapidly transmit water to the ground-water conduit system (high outflow). Land-surface changes that direct more water into the sinkhole may increase the flood peaks, but may not have a substantial effect on the flood durations. Deep sinkholes that have low connectivity to the ground-water conduit system may have a delayed peak water level and may drain slowly, only about 2 to 3 feet in 10 days. Outflow from these sinkholes is limited or restricted by low connectivity to the ground-water conduit system. Land-surface alterations that increase the inflow to the sinkholes can result in high flood levels or increased flood durations.

Reconnaissance of land-use sources of pesticides in drinking water, McKenzie River, Oregon

USGS Publications Warehouse

Kelly, Valerie J.; Anderson, Chauncey W.; Morgenstern, Karl

2012-01-01

The Eugene Water and Electric Board (EWEB) provides water and electricity to the City of Eugene, Oregon, from the McKenzie River. In the spring of 2002, EWEB initiated a pesticide monitoring program in cooperation with the U.S. Geological Survey as part of their Drinking Water Source Protection Plan. Approximately twice yearly pesticide samples were collected from 2002 to 2010 at a suite of sampling sites representing varying land uses in the lower McKenzie River basin. A total of 117 ambient samples were collected from 28 tributary and mainstem sites, including those dominated by forestry, urban, and agricultural activities, as well as the mouths of major tributaries characterized by a mixture of upstream land use. Constituents tested included 175 compounds in filtered water (72 herbicides, 43 insecticides, 10 fungicides, and 36 of their degradation products, as well as 14 pharmaceutical compounds). No attempt was made to sample different site types equivalently; sampling was instead designed primarily to characterize representative storm events during spring and fall runoff conditions in order to assess or confirm the perceived importance of the different site types as sources for pesticides. Sampling was especially limited for agricultural sites, which were only sampled during two spring storm surveys. A total of 43 compounds were detected at least once, with many of these detected only at low concentrations (<0.1 micrograms per liter). Nine compounds were detected at the drinking- water intake, and most of these were reported as estimates less than the laboratory reporting level. Human-health benchmark concentrations were consistently several orders of magnitude higher than detected concentrations at the intake, indicating that pesticide concentrations present a negligible threat to human health. The largest number of pesticide detections occurred during spring storm surveys and primarily were associated with urban stormwater drains. Urban sites also were associated with the highest concentrations, occasionally exceeding 1 microgram per liter. Many of the compounds detected at urban sites were relatively hydrophobic (do not mix easily with water), persistent, and suspected of endocrine disruption. In contrast, forestry compounds were rarely detectable in the McKenzie River, even though forest land predominates in the basin and forestry pesticide use was detected in small tributaries draining forested lands following application. Agricultural pesticide runoff was not well characterized by the limited data available, although a large number of compounds was estimated to be used in the basin and concentrations were moderately high in the few samples collected from small tributaries draining agricultural lands. Results from this analysis indicate that urban pesticide use is potentially an important source for pesticides of concern for drinking water, not limited exclusively to storm conditions. Forestry pesticide use is not considered a likely threat to drinking water quality at the present time (2012). A more complete understanding of agricultural chemicals in runoff in the McKenzie River basin requires further investigation. In addition to evaluating the data collected in this study, a conceptual model describing pesticide contamination in the McKenzie River basin is provided, based on current scientific understanding that is consistent with the data analysis presented in this report. This model is intended to provide a foundation for future monitoring in the basin.

Detecting change in water quality from implementation of limestone treatment systems in a coal-minded watershed

USGS Publications Warehouse

Cravotta,, Charles A.; Weitzel, Jeffrey B.

2000-01-01

During 1996-97, a variety of limestone-based treatment systems were implemented to neutralize acidic mine drainage and reduce the transport of dissolved metals in the northern part of the Swatara Creek watershed, which drains a 43-mi2 (112-km2) area in the Southern Anthracite Field upstream from Ravine, Pa. Since 1996, the current project has monitored water quality upstream and downstream of each treatment and at integrator sites on lower reaches of Swatara Creek. Continuous measurements of pH and specific conductance and periodic sampling for alkalinity, acidity, sulfate, and metals upstream and downstream of each treatment system show that (1) open limestone channels and limestone-sand dosing generally had negligible effects on water quality and (2) limestone diversion wells and limestone drains generally were effective at producing near-neutral pH and attenuating dissolved metals during baseflow but were less effective during stormflow conditions. Storm runoff in this area commonly is acidic, and, as streamflow volume increases during stormflow conditions, a smaller fraction of total flow is treated and (or) residence time in the treatment system is reduced. Monitoring on the mainstem of Swatara Creek indicates watershed-scale effects owing primarily to changes in mining practices and secondarily to watershed-wide implementation of treatment systems. Most underground mines in the Swatara Creek Basin were abandoned before 1960 and are presently flooded. Drainage from these mines contributes substantially to baseflow in Swatara Creek. For Swatara Creek at Ravine, Pa., which is immediately downstream of the mined area, long-term data collected since 1959 indicate sulfate concentration declined from about 150 mg/L in 1959 to 75 mg/L in 1999; pH increased sharply from 3.5-4.4 (median ~4) to 4.6-7.0 (median ~6) after 1975. These trends resulted from a decline in pyrite oxidation and the onset of carbonate buffering. Because these long-term attenuation processes have had such a pronounced effect on water quality in Swatara Creek, the effects of recent implementation of limestone treatments are difficult to detect at a watershed scale. Nevertheless, during ecological surveys prior to 1991, no fish were found in Swatara Creek at Ravine. Only six species of fish were found in 1994 and 1996. However, increasing numbers of fish have been found annually since 1996. In 1999, 21 species of fish were documented. The recent monitoring on the mainstem of Swatara Creek indicates the limestone treatments mitigate extreme fluctuations in pH during storm events; however, additional buffering capacity is needed to maintain near-neutral pH of Swatara Creek during large storm events. Concentration 2 of sulfate, specific conductance, and pH are inversely related to streamflow at Ravine, indicating dilution and acidification during stormflow. Declines in stream-water pH to values approaching 5.0 could result in the remobilization of adsorbed or precipitated metals associated with sediments; declines in pH below 5.0 could cause injury to aquatic organisms. Generally, to maintain stream pH during storms, additional or larger limestone diversion wells could be constructed to begin or increase alkalinity production as the stream stage rises and/or additional or larger limestone drains could be constructed to produce greater amounts of alkalinity and enhance the buffering capacity of baseflow.

Regional and seasonal estimates of fractional storm coverage based on station precipitation observations

NASA Technical Reports Server (NTRS)

Gong, Gavin; Entekhabi, Dara; Salvucci, Guido D.

1994-01-01

Simulated climates using numerical atmospheric general circulation models (GCMs) have been shown to be highly sensitive to the fraction of GCM grid area assumed to be wetted during rain events. The model hydrologic cycle and land-surface water and energy balance are influenced by the parameter bar-kappa, which is the dimensionless fractional wetted area for GCM grids. Hourly precipitation records for over 1700 precipitation stations within the contiguous United States are used to obtain observation-based estimates of fractional wetting that exhibit regional and seasonal variations. The spatial parameter bar-kappa is estimated from the temporal raingauge data using conditional probability relations. Monthly bar-kappa values are estimated for rectangular grid areas over the contiguous United States as defined by the Goddard Institute for Space Studies 4 deg x 5 deg GCM. A bias in the estimates is evident due to the unavoidably sparse raingauge network density, which causes some storms to go undetected by the network. This bias is corrected by deriving the probability of a storm escaping detection by the network. A Monte Carlo simulation study is also conducted that consists of synthetically generated storm arrivals over an artificial grid area. It is used to confirm the bar-kappa estimation procedure and to test the nature of the bias and its correction. These monthly fractional wetting estimates, based on the analysis of station precipitation data, provide an observational basis for assigning the influential parameter bar-kappa in GCM land-surface hydrology parameterizations.

Microanatomy of the intestinal lymphatic system

PubMed Central

Miller, Mark J.; Newberry, Rodney D.

2011-01-01

The intestinal lymphatic system is comprised of two non-communicating lymphatic networks; one containing the lacteals draining the villi and the connecting submucosal lymphatic network, and one containing the lymphatics that drain the intestine muscular layer. These systems deliver lymph into a common network of collecting lymphatics originating near the mesenteric border. The intestinal lymphatic system serves vital functions in the regulation of tissue fluid homeostasis, immune surveillance, and the transport of nutrients, and conversely this system is affected by, and directly contributes to, disease processes within the intestine. Recent discoveries of specific lymphatic markers, factors promoting lymphangiogenesis, and factors selectively affecting the development of intestinal lymphatics hold promise for unlocking the role of lymphatics in the pathogenesis of diseases affecting the intestine and for intestinal lymphatic selective therapies. Vital to progress in understanding how the intestinal lymphatic system functions is integrating of recent advances identifying molecular pathways for lymphatic growth and remodeling with advanced imaging modalities to observe lymphatic function and dysfunction in vivo. PMID:20961303

Mapping and Visualization of Storm-Surge Dynamics for Hurricane Katrina and Hurricane Rita

USGS Publications Warehouse

Gesch, Dean B.

2009-01-01

The damages caused by the storm surges from Hurricane Katrina and Hurricane Rita were significant and occurred over broad areas. Storm-surge maps are among the most useful geospatial datasets for hurricane recovery, impact assessments, and mitigation planning for future storms. Surveyed high-water marks were used to generate a maximum storm-surge surface for Hurricane Katrina extending from eastern Louisiana to Mobile Bay, Alabama. The interpolated surface was intersected with high-resolution lidar elevation data covering the study area to produce a highly detailed digital storm-surge inundation map. The storm-surge dataset and related data are available for display and query in a Web-based viewer application. A unique water-level dataset from a network of portable pressure sensors deployed in the days just prior to Hurricane Rita's landfall captured the hurricane's storm surge. The recorded sensor data provided water-level measurements with a very high temporal resolution at surveyed point locations. The resulting dataset was used to generate a time series of storm-surge surfaces that documents the surge dynamics in a new, spatially explicit way. The temporal information contained in the multiple storm-surge surfaces can be visualized in a number of ways to portray how the surge interacted with and was affected by land surface features. Spatially explicit storm-surge products can be useful for a variety of hurricane impact assessments, especially studies of wetland and land changes where knowledge of the extent and magnitude of storm-surge flooding is critical.

Global Ionospheric Perturbations Monitored by the Worldwide GPS Network

NASA Technical Reports Server (NTRS)

Ho, C. M.; Mannucci, A. T.; Lindqwister, U. J.; Pi, X. Q.

1996-01-01

Based on the delays of these (Global Positioning System-GPS)signals, we have generated high resolution global ionospheric TEC (Total Electronic Changes) maps at 15-minute intervals. Using a differential method comparing storm time maps with quiet time maps, we find that the ionopshere during this time storm has increased significantly (the percentage change relative to quiet times is greater than 150 percent) ...These preliminary results (those mentioned above plus other in the paper)indicate that the differential maping method, which is based on GPS network measurements appears to be a useful tool for studying the global pattern and evolution process of the entire ionospheric perturbation.

GLM Validation Studies in Colorado

NASA Astrophysics Data System (ADS)

Rutledge, S. A.; Reimel, K.; Fuchs, B.; Xu, W.

2017-12-01

On 8 May 2017 the Geostationary Lightning Mapper (GLM) calibration/validation field campaign completed a mission over the domain of the Colorado Lightning Mapping Array (LMA). This "gold mine day" produced a mixture of normal polarity and anomalous storms of varying intensity. A case study analysis has been completed for a portion of three individual storms from this day. By utilizing a cell tracking algorithm and lightning flash attribution program, individual lightning flashes detected by the GLM, LMA, the National Lightning Detection Network (NLDN), and Earth Networks Total Lightning Network (ENTLN) are attributed to individual storm cells. The focus of this analysis is the detection efficiency of GLM. We will discuss how the GLM detection efficiency changes as a result of storm morphology and lightning flash characteristics. Lightning flash size, flash height, and the amount of ice present between the lightning flash altitude and the top of the cloud all appear to play a role in how well GLM detects lightning flashes. Since GLM shares the same concept as its predecessor TRMM LIS (optically-based lightning detection), the evaluation of TRMM LIS against LMA network-detected lightning provides insights into the GLM detection efficiency. We have collected observations by LIS and LMA coincident in time and space during 2008-2014. The sample includes 400 LIS overpasses with both LIS and LMA detecting flashes within 150 km radius of the center of the LMA array during the 120 second LIS observing time period (analysis presently confined to the Alabama LMA network). The overall LIS detection efficiency (DE, defined as the ratio of flash rates between LIS and LMA) is 0.45, with higher DE for lower flash rate cases. LIS showed a DE of nearly 100% for cases with flash rates < 10 fl/min, but had a DE of only 20-30% for high flash rates within intense storms (> 300 fl/min). We further separated the dataset into day and night, and found that the night-time DE (0.6) increased by 20% compared to day-time DE (0.5). LIS DE also increased as a function of LMA-derived flash size, possibly due to stronger radiance from larger flashes. LIS DE was the lowest ( 40%) for flashes with sizes smaller than a single LIS pixel (< 16 km2). These results may be applicable to GLM as well.

Validation of a global satellite rainfall product for real time monitoring of meteorological extremes

NASA Astrophysics Data System (ADS)

Cánovas-García, Fulgencio; García-Galiano, Sandra; Karbalaee, Negar

2017-10-01

The real time monitoring of storms is important for the management and prevention of flood risks. However, in the southeast of Spain, it seems that the density of the rain gauge network may not be sufficient to adequately characterize the rainfall spatial distribution or the high rainfall intensities that are reached during storms. Satellite precipitation products such as PERSIANN-CCS (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks - Cloud Classification System) could be used to complement the automatic rain gauge networks and so help solve this problem. However, the PERSIANN-CCS product has only recently become available, so its operational validity for areas such as south-eastern Spain is not yet known. In this work, a methodology for the hourly validation of PERSIANN-CCS is presented. We used the rain gauge stations of the SIAM (Sistema de Información Agraria de Murcia) network to study three storms with a very high return period. These storms hit the east and southeast of the Iberian Peninsula and resulted in the loss of human life, major damage to agricultural crops and a strong impact on many different types of infrastructure. The study area is the province of Murcia (Region of Murcia), located in the southeast of the Iberian Peninsula, covering an area of more than 11,000 km2 and with a population of almost 1.5 million. In order to validate the PERSIANN-CCS product for these three storms, contrasts were made with the hyetographs registered by the automatic rain gauges, analyzing statistics such as bias, mean square difference and Pearson's correlation coefficient. Although in some cases the temporal distribution of rainfall was well captured by PERSIANN-CCS, in several rain gauges high intensities were not properly represented. The differences were strongly correlated with the rain gauge precipitation, but not with satellite-obtained rainfall. The main conclusion concerns the need for specific local calibration for the study area if PERSIANN-CCS is to be used as an operational tool for the monitoring of extreme meteorological phenomena.

Probability and volume of potential postwildfire debris flows in the 2012 Waldo Canyon Burn Area near Colorado Springs, Colorado

USGS Publications Warehouse

Verdin, Kristine L.; Dupree, Jean A.; Elliott, John G.

2012-01-01

This report presents a preliminary emergency assessment of the debris-flow hazards from drainage basins burned by the 2012 Waldo Canyon fire near Colorado Springs in El Paso County, Colorado. Empirical models derived from statistical evaluation of data collected from recently burned basins throughout the intermountain western United States were used to estimate the probability of debris-flow occurrence and potential volume of debris flows along the drainage network of the burned area and to estimate the same for 22 selected drainage basins along U.S. Highway 24 and the perimeter of the burned area. Input data for the models included topographic parameters, soil characteristics, burn severity, and rainfall totals and intensities for a (1) 2-year-recurrence, 1-hour-duration rainfall, referred to as a 2-year storm (29 millimeters); (2) 10-year-recurrence, 1-hour-duration rainfall, referred to as a 10-year storm (42 millimeters); and (3) 25-year-recurrence, 1-hour-duration rainfall, referred to as a 25-year storm (48 millimeters). Estimated debris-flow probabilities at the pour points of the the drainage basins of interest ranged from less than 1 to 54 percent in response to the 2-year storm; from less than 1 to 74 percent in response to the 10-year storm; and from less than 1 to 82 percent in response to the 25-year storm. Basins and drainage networks with the highest probabilities tended to be those on the southern and southeastern edge of the burn area where soils have relatively high clay contents and gradients are steep. Nine of the 22 drainage basins of interest have greater than a 40-percent probability of producing a debris flow in response to the 10-year storm. Estimated debris-flow volumes for all rainfalls modeled range from a low of 1,500 cubic meters to a high of greater than 100,000 cubic meters. Estimated debris-flow volumes increase with basin size and distance along the drainage network, but some smaller drainages were also predicted to produce substantial volumes of material. The predicted probabilities and some of the volumes predicted for the modeled storms indicate a potential for substantial debris-flow impacts on structures, reservoirs, roads, bridges, and culverts located both within and immediately downstream from the burned area. U.S. Highway 24, on the southern edge of the burn area, is also susceptible to impacts from debris flows.

Assessing the Impacts of Land-Use Change and Ecological Restoration on CH4 and CO2 Fluxes in the Sacramento-San Joaquin Delta, California: Findings from a Regional Network of Eddy Covariance Towers

NASA Astrophysics Data System (ADS)

Knox, S. H.; Sturtevant, C. S.; Oikawa, P. Y.; Matthes, J. H.; Koteen, L. E.; Anderson, F. E.; Verfaillie, J. G.; Baldocchi, D. D.

2014-12-01

The new generation of open-path, low power, laser spectrometers has allowed us to measure methane (CH4) fluxes continuously in remote regions and answer new and exciting questions on the spatial and temporal variability of greenhouse gas (GHG) fluxes using networks of eddy covariance (EC) towers. Our research is focused in the Sacramento-San Joaquin Delta where we have installed a regional network of flux towers to assess the impacts of land-use change and ecological restoration on CH4 and CO2 fluxes. The Delta was drained for agriculture over a century ago and has since has experienced high rates of subsidence. It is recognized that agriculture on drained peat soils in the Delta is unsustainable in the long-term, and to help reverse subsidence and capture carbon (C) there is an interest in restoring drained land-use types to flooded conditions. However, flooding increases CH4 emissions. We conducted multiple years of simultaneous EC measurements at drained agricultural peatlands (a pasture, a corn field and an alfalfa field) and flooded land-use types (a rice paddy and 3 restored wetlands) to assess the impact of drained to flooded land-use change on CO2 and CH4 fluxes. Since these sites are all within 20 km of each other, they share the same basic meteorology, enabling a direct comparison of differences in the C and GHG budgets between sites. Using a multi-tower approach we found that converting drained agricultural peatlands to flooded land-use types can help reverse soil subsidence and reduce GHG emissions from the Delta. Furthermore, there is a growing interest in wetland restoration in California to generate C credits for both the voluntary C market and the state's cap-and-trade program. However, information on GHG fluxes from restored wetlands is lacking. Using multi-year measurements of GHG fluxes from restored wetlands of varying ages, our research also aims to understand how CO2 and CH4 fluxes from restored wetlands vary during ecosystem development, determine the daily and seasonal forcings controlling these fluxes, and assess management strategies that can help minimize CH4 fluxes and maximize C uptake in restored wetlands. Our multi-year multi-site research program is beginning to answer these questions and bridge understanding between biometeorology, biogeochemistry and climate policy.

Data Quality Control: Challenges, Methods, and Solutions from an Eco-Hydrologic Instrumentation Network

NASA Astrophysics Data System (ADS)

Eiriksson, D.; Jones, A. S.; Horsburgh, J. S.; Cox, C.; Dastrup, D.

2017-12-01

Over the past few decades, advances in electronic dataloggers and in situ sensor technology have revolutionized our ability to monitor air, soil, and water to address questions in the environmental sciences. The increased spatial and temporal resolution of in situ data is alluring. However, an often overlooked aspect of these advances are the challenges data managers and technicians face in performing quality control on millions of data points collected every year. While there is general agreement that high quantities of data offer little value unless the data are of high quality, it is commonly understood that despite efforts toward quality assurance, environmental data collection occasionally goes wrong. After identifying erroneous data, data managers and technicians must determine whether to flag, delete, leave unaltered, or retroactively correct suspect data. While individual instrumentation networks often develop their own QA/QC procedures, there is a scarcity of consensus and literature regarding specific solutions and methods for correcting data. This may be because back correction efforts are time consuming, so suspect data are often simply abandoned. Correction techniques are also rarely reported in the literature, likely because corrections are often performed by technicians rather than the researchers who write the scientific papers. Details of correction procedures are often glossed over as a minor component of data collection and processing. To help address this disconnect, we present case studies of quality control challenges, solutions, and lessons learned from a large scale, multi-watershed environmental observatory in Northern Utah that monitors Gradients Along Mountain to Urban Transitions (GAMUT). The GAMUT network consists of over 40 individual climate, water quality, and storm drain monitoring stations that have collected more than 200 million unique data points in four years of operation. In all of our examples, we emphasize that scientists should remain skeptical and seek independent verification of sensor data, even for sensors purchased from trusted manufacturers.

Data Requirements for Ceiling and Visibility Products Development

DTIC Science & Technology

1994-04-13

and Water - Cycle Experiment (GEWEX), STORM 1, and the Naval Research Laboratory’s Coastal Me- teorology Accelerated Research Initiative field... Water - Cycle Experiment HPCN High Plains Climate Network lOP Intensive Observation Period ICN Illinois Climate Network ITWS Integrated Terminal Weather

Statistical Downscaling of Gusts During Extreme European Winter Storms Using Radial-Basis-Function Networks

NASA Astrophysics Data System (ADS)

Voigt, M.; Lorenz, P.; Kruschke, T.; Osinski, R.; Ulbrich, U.; Leckebusch, G. C.

2012-04-01

Winterstorms and related gusts can cause extensive socio-economic damages. Knowledge about the occurrence and the small scale structure of such events may help to make regional estimations of storm losses. For a high spatial and temporal representation, the use of dynamical downscaling methods (RCM) is a cost-intensive and time-consuming option and therefore only applicable for a limited number of events. The current study explores a methodology to provide a statistical downscaling, which offers small scale structured gust fields from an extended large scale structured eventset. Radial-basis-function (RBF) networks in combination with bidirectional Kohonen (BDK) maps are used to generate the gustfields on a spatial resolution of 7 km from the 6-hourly mean sea level pressure field from ECMWF reanalysis data. BDK maps are a kind of neural network which handles supervised classification problems. In this study they are used to provide prototypes for the RBF network and give a first order approximation for the output data. A further interpolation is done by the RBF network. For the training process the 50 most extreme storm events over the North Atlantic area from 1957 to 2011 are used, which have been selected from ECMWF reanalysis datasets ERA40 and ERA-Interim by an objective wind based tracking algorithm. These events were downscaled dynamically by application of the DWD model chain GME → COSMO-EU. Different model parameters and their influence on the quality of the generated high-resolution gustfields are studied. It is shown that the statistical RBF network approach delivers reasonable results in modeling the regional gust fields for untrained events.

Mitigation of Flood Hazards Through Modification of Urban Channels and Floodplains

NASA Astrophysics Data System (ADS)

Miller, A. J.; Lee, G.; Bledsoe, B. P.; Stephens, T.

2017-12-01

Small urban watersheds with high percent impervious cover and dense road and storm-drain networks are highly responsive to short-duration high-intensity rainfall events that lead to flash floods. The Baltimore metropolitan area has some of the flashiest urban watersheds in the conterminous U.S., high frequency of channel incision in affected areas, and a large number of watershed restoration projects designed to restore ecosystem services through reconnection of the channel with the floodplain. A question of key importance in these and other urban watersheds is to what extent we can mitigate flood hazards and urban stream syndrome through restoration activities that modify the channel and valley floor. Local and state governments have invested resources in repairing damage caused by extreme events like the July 30, 2016 Ellicott City flood in the Tiber River watershed, as well as more frequent high flows in other local urban streams. Recent reports have investigated how much flood mitigation may be achieved through modification of the channel and floodplain to enhance short-term storage of flood waters on the valley floor or in other subsurface structures, as compared with increasing stormwater management in the headwaters. Ongoing research conducted as part of the UWIN (Urban Water Innovation Network) program utilizes high-resolution topographic point clouds derived by processing of photographs from hand-held cameras or video frames from drone overflights. These are used both to track geomorphic change and to assess flood response with 2d hydraulic modeling tools under alternative mitigation scenarios. Assessment metrics include variations in inundation extent, water depth, hydrograph attenuation, and temporal and spatial characteristics of the 2d depth-averaged velocity field. Examples from diverse urban watersheds are presented to illustrate the range of anticipated outcomes and potential constraints on the effectiveness of downstream vs. headwater mitigation efforts.

Using Satellite Imagery to Quantify Water Quality Impacts and Recovery from Hurricane Harvey

NASA Astrophysics Data System (ADS)

Sobel, R. S.; Kiaghadi, A.; Rifai, H. S.

2017-12-01

Record rainfall during Hurricane Harvey in the Houston-Galveston region generated record flows containing suspended sediment that was likely contaminated. Conventional water quality monitoring requires resource intensive field campaigns, and produces sparse datasets. In this study, satellite data were used to quantify suspended sediment (TSS) concentrations and mass within the region's estuary system and to estimate sediment deposition and transport. A conservative two band, red-green empirical regression was developed from the Sentinel 2 satellite to calculate TSS concentrations and masses. The regression was calibrated with an R2 = 0.73 (n=28) and validated with an R2 = 0.75 (n=12) using 2016 & 2017 imagery. TSS concentrations four days, 14 days, and 44 days post-storm were compared with a reference condition three days before storm arrival. Results indicated that TSS concentrations were an average of 100% higher four days post-storm, and 150% higher after 14 days, however, the average concentration on day 144 was only seven percent higher than the reference condition, suggesting the estuary system is approaching recovery to pre-storm conditions. Sediment masses were determined from the regressed concentrations and water volumes estimated from a bottom elevation grid combined with water surface elevations observed coincidently with the satellite image. While water volumes were only 13% higher on both day four and day 14 post-storm; sediment masses were 195% and 227% higher than the reference condition, respectively. By day 44, estuary sediment mass returned to just 2.9% above the reference load. From a mechanistic standpoint, the elevated TSS concentrations on day four indicated an advection-based regime due to stormwater runoff draining through the estuarine system. Sometime, however, between days 14 and 44, transport conditions switched from advection-dominated to deposition-driven as indicated by the near normal TSS concentrations on day 44.

Effects of suburban development on runoff generation in the Croton River basin, New York, USA

USGS Publications Warehouse

Burns, D.; Vitvar, T.; McDonnell, J.; Hassett, J.; Duncan, J.; Kendall, C.

2005-01-01

The effects of impervious area, septic leach-field effluent, and a riparian wetland on runoff generation were studied in three small (0.38-0.56 km 2) headwater catchments that represent a range of suburban development (high density residential, medium density residential, and undeveloped) within the Croton River basin, 70 km north of New York City. Precipitation, stream discharge, and groundwater levels were monitored at 10-30 min intervals for 1 year, and stream water and groundwater samples were collected biweekly for ??18O, NO3-, and SO42- analysis for more than 2 years during an overlapping period in 2000-2002. Data from 27 storms confirmed that peak magnitudes increased and recession time decreased with increasing development, but lags in peak arrival and peak discharge/mean discharge were greatest in the medium density residential catchment, which contains a wetland in which storm runoff is retained before entering the stream. Baseflow during a dry period from Aug. 2001-Feb. 2002 was greatest in the high-density residential catchment, presumably from the discharge of septic effluent through the shallow groundwater system and into the stream. In contrast, moderate flows during a wet period from Mar.-Aug. 2002 were greatest in the undeveloped catchment, possibly as a result of greater subsurface storage or greater hydraulic conductivity at this site. The mean residence time of baseflow was about 30 weeks at all three catchments, indicating that human influence was insufficient to greatly affect the groundwater recharge and discharge properties that determine catchment residence time. These results suggest that while suburban development and its associated impervious surfaces and storm drains accelerate the transport of storm runoff into streams, the combined effects of remnant natural landscape features such as wetlands and human alterations such as deep groundwater supply and septic systems can change the expected effects of human development on storm runoff and groundwater recharge. ?? 2005 Elsevier B.V. All rights reserved.

Coupling Fluvial and Oceanic Drivers in Flooding Forecasts for San Francisco Bay

NASA Astrophysics Data System (ADS)

Herdman, L.; Kim, J.; Cifelli, R.; Barnard, P.; Erikson, L. H.; Johnson, L. E.; Chandrasekar, V.

2016-12-01

San Francisco Bay is a highly urbanized estuary and the surrounding communities are susceptible to flooding along the bay shoreline and inland rivers and creeks that drain to the Bay. A forecast model that integrates fluvial and oceanic drivers is necessary for predicting flooding in this complex urban environment. This study introduces the state-of-the-art coupling of the USGS Coastal Storm Modeling System (CoSMoS) with the NWS Research Distributed Hydrologic Model (RDHM) for San Francisco Bay. For this application, we utilize Delft3D-FM, a hydrodynamic model based on a flexible mesh grid, to calculate water levels that account for tidal forcing, seasonal water level anomalies, surge and in-Bay generated wind waves from the wind and pressure fields of a NWS forecast model. The tributary discharges from RDHM are dynamic, meteorologically driven allowing for operational use of CoSMoS which has previously relied on statistical estimates of river discharge. The flooding extent is determined by overlaying the resulting maximum water levels onto a recently updated 2-m digital elevation model of the study area which best resolves the extensive levee and tidal marsh systems in the region. The results we present here are focused on the interaction of the Bay and the Napa River watershed. This study demonstrates the interoperability of the CoSMoS and RDHM prediction models. We also use this pilot region to examine storm flooding impacts in a series of storm scenarios that simulate 5-100yr return period events in terms of either coastal or fluvial events. These scenarios demonstrate the wide range of possible flooding outcomes considering rainfall recurrence intervals, soil moisture conditions, storm surge, wind speed, and tides (spring and neap). With a simulated set of over 25 storm scenarios we show how the extent, level, and duration of flooding is dependent on these atmospheric and hydrologic parameters and we also determine a range of likely flood events.

Predicting thunderstorm evolution using ground-based lightning detection networks

NASA Technical Reports Server (NTRS)

Goodman, Steven J.

1990-01-01

Lightning measurements acquired principally by a ground-based network of magnetic direction finders are used to diagnose and predict the existence, temporal evolution, and decay of thunderstorms over a wide range of space and time scales extending over four orders of magnitude. The non-linear growth and decay of thunderstorms and their accompanying cloud-to-ground lightning activity is described by the three parameter logistic growth model. The growth rate is shown to be a function of the storm size and duration, and the limiting value of the total lightning activity is related to the available energy in the environment. A new technique is described for removing systematic bearing errors from direction finder data where radar echoes are used to constrain site error correction and optimization (best point estimate) algorithms. A nearest neighbor pattern recognition algorithm is employed to cluster the discrete lightning discharges into storm cells and the advantages and limitations of different clustering strategies for storm identification and tracking are examined.

Report on the survey for electrostatic discharges on Mars using NASA's Deep Space Network (DSN)

NASA Astrophysics Data System (ADS)

Arabshahi, S.; Majid, W.; Geldzahler, B.; Kocz, J.; Schulter, T.; White, L.

2017-12-01

Mars atmosphere has strong dust activity. It is suggested that the larger regional storms are capable of producing electric fields large enough to initiate electrostatic discharges. The storms have charging process similar to terrestrial dust devils and have hot cores and complicated vortex winds similar to terrestrial thunderstorms. However, due to uncertainties in our understanding of the electrical environment of the storms and absence of related in-situ measurements, the existence (or non-existence) of such electrostatic discharges on the planet is yet to be confirmed. Knowing about the electrical activity on Mars is essential for future human explorations of the planet. We have recently launched a long-term monitoring campaign at NASA's Madrid Deep Space Communication Complex (MDSCC) to search for powerful discharges on Mars. The search occurs during routine tracking of Mars orbiting spacecraft by Deep Space Network (DSN) radio telescope. In this presentation, we will report on the result of processing and analysis of the data from the first six months of our campaign.

Soil moisture dynamics and their effect on bioretention performance in Northeast Ohio

NASA Astrophysics Data System (ADS)

Bush, S. A.; Jefferson, A.; Jarden, K.; Kinsman-Costello, L. E.; Grieser, J.

2014-12-01

Urban impervious surfaces lead to increases in stormwater runoff. Green infrastructure, like bioretention cells, is being used to mitigate negative impacts of runoff by disconnecting impervious surfaces from storm water systems and redirecting flow to decentralized treatment areas. While bioretention soil characteristics are carefully designed, little research is available on soil moisture dynamics within the cells and how these might relate to inter-storm variability in performance. Bioretentions have been installed along a residential street in Parma, Ohio to determine the impact of green infrastructure on the West Creek watershed, a 36 km2 subwatershed of the Cuyahoga River. Bioretentions were installed in two phases (Phase I in 2013 and Phase II in 2014); design and vegetation density vary slightly between the two phases. Our research focuses on characterizing soil moisture dynamics of multiple bioretentions and assessing their impact on stormwater runoff at the street scale. Soil moisture measurements were collected in transects for eight bioretentions over the course of one summer. Vegetation indices of canopy height, percent vegetative cover, species richness and NDVI were also measured. A flow meter in the storm drain at the end of the street measured storm sewer discharge. Precipitation was recorded from a meteorological station 2 km from the research site. Soil moisture increased in response to precipitation and decreased to relatively stable conditions within 3 days following a rain event. Phase II bioretentions exhibited greater soil moisture and less vegetation than Phase I bioretentions, though the relationship between soil moisture and vegetative cover is inconclusive for bioretentions constructed in the same phase. Data from five storms suggest that pre-event soil moisture does not control the runoff-to-rainfall ratio, which we use as a measure of bioretention performance. However, discharge data indicate that hydrograph characteristics, such as lag time and peak flow, are altered relative to a control street. This analysis suggests that street-scale implementation of bioretention can reduce the impact of impervious surface on stormflows, but more information is needed to fully understand how soil moisture of the bioretentions affects inter-storm variability in performance.

A Sequence of Flushing and Drying of Breeding Habitats of Aedes aegypti (L.) Prior to the Low Dengue Season in Singapore

PubMed Central

Seidahmed, Osama M. E.; Eltahir, Elfatih A. B.

2016-01-01

In dengue-endemic areas, transmission shows both a seasonal and interannual variability. To investigate how rainfall impacts dengue seasonality in Singapore, we carried out a longitudinal survey in the Geylang neighborhood from August 2014 to August 2015. The survey comprised of twice-weekly random inspections to outdoor breeding habitats and continuous monitoring for positive ones. In addition, observations of rainstorms were collected. Out of 6824 inspected habitats, 67 contained Aedes aegypti, 11 contained Aedes albopictus and 24 contained Culex spp. The main outdoors habitat of Aedes aegypti was storm drains (54/67). We found that 80% of breeding sites in drains (43/54) were lost after intense rainstorms related to the wet phase of the Northeast monsoon (NE) between November 2014 and early January 2015. Subsequently, 95% (41/43) of these flushed drains had dried out during the dry phase of the NE in late January-February 2015. A return in the outdoor breeding of Aedes aegypti was observed after the onset of Southwest monsoon (SW) between May and August 2015. There was also a reduction in productivity of breeding habitats for larvae and pupae after the onset of the NE. In wet equatorial regions like Singapore, rainfall varies with the monsoons. A monsoon-driven sequence of flushing and drying shapes the outdoor seasonal abundance of Aedes aegypti. This finding can be used to optimize vector control strategies and better understand dengue in the context of climate change. PMID:27459322

A Sequence of Flushing and Drying of Breeding Habitats of Aedes aegypti (L.) Prior to the Low Dengue Season in Singapore.

PubMed

Seidahmed, Osama M E; Eltahir, Elfatih A B

2016-07-01

In dengue-endemic areas, transmission shows both a seasonal and interannual variability. To investigate how rainfall impacts dengue seasonality in Singapore, we carried out a longitudinal survey in the Geylang neighborhood from August 2014 to August 2015. The survey comprised of twice-weekly random inspections to outdoor breeding habitats and continuous monitoring for positive ones. In addition, observations of rainstorms were collected. Out of 6824 inspected habitats, 67 contained Aedes aegypti, 11 contained Aedes albopictus and 24 contained Culex spp. The main outdoors habitat of Aedes aegypti was storm drains (54/67). We found that 80% of breeding sites in drains (43/54) were lost after intense rainstorms related to the wet phase of the Northeast monsoon (NE) between November 2014 and early January 2015. Subsequently, 95% (41/43) of these flushed drains had dried out during the dry phase of the NE in late January-February 2015. A return in the outdoor breeding of Aedes aegypti was observed after the onset of Southwest monsoon (SW) between May and August 2015. There was also a reduction in productivity of breeding habitats for larvae and pupae after the onset of the NE. In wet equatorial regions like Singapore, rainfall varies with the monsoons. A monsoon-driven sequence of flushing and drying shapes the outdoor seasonal abundance of Aedes aegypti. This finding can be used to optimize vector control strategies and better understand dengue in the context of climate change.

Household disaster preparedness and information sources: Rapid cluster survey after a storm in New South Wales, Australia

PubMed Central

Cretikos, Michelle; Eastwood, Keith; Dalton, Craig; Merritt, Tony; Tuyl, Frank; Winn, Linda; Durrheim, David

2008-01-01

Background A storm-related disaster in New South Wales, Australia in June 2007 caused infrastructure damage, interrupted essential services, and presented major public health risks. We investigated household disaster preparedness and information sources used before and during the disaster. Methods Rapid cluster survey of 320 randomly selected households in Newcastle and Lake Macquarie, New South Wales, Australia. Results 227 households (71%) responded to the survey. By the day before the storm, 48% (95%CI 40–57%) of households were aware of a storm warning, principally through television (67%; 58–75%) and radio (57%; 49–66%) announcements. Storm preparations were made by 42% (28–56%) of these households. Storm information sources included: radio (78%; 68–88%); family, friends, colleagues and neighbours (50%; 40–60%); and television (41%; 30–52%). Radio was considered more useful than television (62%; 51–73% vs. 29%; 18–40%), even in households where electricity supply was uninterrupted (52%; 31–73% vs. 41%; 20–63%). Only 23% (16–30%) of households were aware that the local government-operated radio network has a designated communication role during disasters. A battery-operated household radio and appropriate batteries were available in 42% (34–50%) of households, while only 23% (16–29%) had all of: a torch, battery-operated radio, appropriate batteries, mobile phone, emergency contact list and first aid equipment. Conclusion Broadcast media are important information sources immediately before and during disasters. Health services should promote awareness of broadcast networks' disaster role, especially the role of radio, and encourage general household disaster preparedness. A rapid cluster survey conducted shortly after a natural disaster provided practical, robust information for disaster planning. PMID:18533010

Translating sickle cell guidelines into practice for primary care providers with Project ECHO

PubMed Central

Shook, Lisa M.; Farrell, Christina B.; Kalinyak, Karen A.; Nelson, Stephen C.; Hardesty, Brandon M.; Rampersad, Angeli G.; Saving, Kay L.; Whitten-Shurney, Wanda J.; Panepinto, Julie A.; Ware, Russell E.; Crosby, Lori E.

2016-01-01

Background Approximately 100,000 persons with sickle cell disease (SCD) live in the United States, including 15,000 in the Midwest. Unfortunately, many patients experience poor health outcomes due to limited access to primary care providers (PCPs) who are prepared to deliver evidence-based SCD care. Sickle Treatment and Outcomes Research in the Midwest (STORM) is a regional network established to improve care and outcomes for individuals with SCD living in Indiana, Illinois, Michigan, Minnesota, Ohio, and Wisconsin. Methods STORM investigators hypothesized that Project ECHO® methodology could be replicated to create a low-cost, high-impact intervention to train PCPs in evidence-based care for pediatric and young adult patients with SCD in the Midwest, called STORM TeleECHO. This approach utilizes video technology for monthly telementoring clinics consisting of didactic and case-based presentations focused on the National Heart, Lung and Blood Institute (NHLBI) evidence-based guidelines for SCD. Results Network leads in each of the STORM states assisted with developing the curriculum and are recruiting providers for monthly clinics. To assess STORM TeleECHO feasibility and acceptability, monthly attendance and satisfaction data are collected. Changes in self-reported knowledge, comfort, and practice patterns will be compared with pre-participation, and 6 and 12 months after participation. Conclusions STORM TeleECHO has the potential to increase implementation of the NHLBI evidence-based guidelines, especially increased use of hydroxyurea, resulting in improvements in the quality of care and outcomes for children and young adults with SCD. This model could be replicated in other pediatric chronic illness conditions to improve PCP knowledge and confidence in delivering evidence-based care. PMID:27887664

Parameter Estimation for a Model of Space-Time Rainfall

NASA Astrophysics Data System (ADS)

Smith, James A.; Karr, Alan F.

1985-08-01

In this paper, parameter estimation procedures, based on data from a network of rainfall gages, are developed for a class of space-time rainfall models. The models, which are designed to represent the spatial distribution of daily rainfall, have three components, one that governs the temporal occurrence of storms, a second that distributes rain cells spatially for a given storm, and a third that determines the rainfall pattern within a rain cell. Maximum likelihood and method of moments procedures are developed. We illustrate that limitations on model structure are imposed by restricting data sources to rain gage networks. The estimation procedures are applied to a 240-mi2 (621 km2) catchment in the Potomac River basin.

Empirical Orthogonal Function (EOF) Analysis of Storm-Time GPS Total Electron Content Variations

NASA Astrophysics Data System (ADS)

Thomas, E. G.; Coster, A. J.; Zhang, S.; McGranaghan, R. M.; Shepherd, S. G.; Baker, J. B.; Ruohoniemi, J. M.

2016-12-01

Large perturbations in ionospheric density are known to occur during geomagnetic storms triggered by dynamic structures in the solar wind. These ionospheric storm effects have long attracted interest due to their impact on the propagation characteristics of radio wave communications. Over the last two decades, maps of vertically-integrated total electron content (TEC) based on data collected by worldwide networks of Global Positioning System (GPS) receivers have dramatically improved our ability to monitor the spatiotemporal dynamics of prominent storm-time features such as polar cap patches and storm enhanced density (SED) plumes. In this study, we use an empirical orthogonal function (EOF) decomposition technique to identify the primary modes of spatial and temporal variability in the storm-time GPS TEC response at midlatitudes over North America during more than 100 moderate geomagnetic storms from 2001-2013. We next examine the resulting time-varying principal components and their correlation with various geophysical indices and parameters in order to derive an analytical representation. Finally, we use a truncated reconstruction of the EOF basis functions and parameterization of the principal components to produce an empirical representation of the geomagnetic storm-time response of GPS TEC for all magnetic local times local times and seasons at midlatitudes in the North American sector.

Inferring Spatio-temporal Variations in the Risk of Extreme Precipitation in the Western United States from Tree-ring Chronologies

NASA Astrophysics Data System (ADS)

Steinschneider, S.; Ho, M.; Cook, E. R.; Lall, U.

2017-12-01

This work explores how extreme cold-season precipitation dynamics along the west coast of the United States have varied in the past under natural climate variability through an analysis of the moisture anomalies recorded by tree-ring chronologies across the coast and interior of the western U.S. Winters with high total precipitation amounts in the coastal regions are marked by a small number of extreme storms that exhibit distinct spatial patterns of precipitation across the coast and further inland. Building from this observation, this work develops a novel application of dendroclimatic evidence to explore the following questions: a) how is extreme precipitation variability expressed in a network of tree-ring chronologies; b) can this information provide insight on the space-time variability of storm tracks that cause these extreme events; and c) how can the joint variability of extreme precipitation and storm tracks be modeled to develop consistent, multi-centennial reconstructions of both? We use gridded, tree-ring based reconstructions of the summer Palmer Drought Severity Index (PDSI) extending back 500 years within the western U.S. to build and test a novel statistical framework for reconstructing the space-time variability of coastal extreme precipitation and the associated wintertime storm tracks. Within this framework, we (1) identify joint modes of variability of extreme precipitation fields and tree-ring based PDSI reconstructions; (2) relate these modes to previously identified, unique storm track patterns associated with atmospheric rivers (ARs), which are the dominant type of storm that is responsible for extreme precipitation in the region; and (3) determine latitudinal variations of landfalling ARs across the west coast and their relationship to the these joint modes. To our knowledge, this work is the first attempt to leverage information on storm track patterns stored in a network of paleoclimate proxies to improve reconstruction fidelity.

Inferring Spatio-temporal Variations in the Risk of Extreme Precipitation in the Western United States from Tree-ring Chronologies

NASA Astrophysics Data System (ADS)

Steinschneider, S.; Ho, M.; Cook, E. R.; Lall, U.

2016-12-01

This work explores how extreme cold-season precipitation dynamics along the west coast of the United States have varied in the past under natural climate variability through an analysis of the moisture anomalies recorded by tree-ring chronologies across the coast and interior of the western U.S. Winters with high total precipitation amounts in the coastal regions are marked by a small number of extreme storms that exhibit distinct spatial patterns of precipitation across the coast and further inland. Building from this observation, this work develops a novel application of dendroclimatic evidence to explore the following questions: a) how is extreme precipitation variability expressed in a network of tree-ring chronologies; b) can this information provide insight on the space-time variability of storm tracks that cause these extreme events; and c) how can the joint variability of extreme precipitation and storm tracks be modeled to develop consistent, multi-centennial reconstructions of both? We use gridded, tree-ring based reconstructions of the summer Palmer Drought Severity Index (PDSI) extending back 500 years within the western U.S. to build and test a novel statistical framework for reconstructing the space-time variability of coastal extreme precipitation and the associated wintertime storm tracks. Within this framework, we (1) identify joint modes of variability of extreme precipitation fields and tree-ring based PDSI reconstructions; (2) relate these modes to previously identified, unique storm track patterns associated with atmospheric rivers (ARs), which are the dominant type of storm that is responsible for extreme precipitation in the region; and (3) determine latitudinal variations of landfalling ARs across the west coast and their relationship to the these joint modes. To our knowledge, this work is the first attempt to leverage information on storm track patterns stored in a network of paleoclimate proxies to improve reconstruction fidelity.

Identifying agricultural land management successes and water quality improvements at the sub-watershed scale: A case study in south-central Minnesota

NASA Astrophysics Data System (ADS)

Perry, M.; Triplett, L.; Smith, C.; Westfield, J.; Clause, C.

2017-12-01

In agricultural regions with highly-impacted water quality, it can be challenging to generate local motivation for water improvement efforts. Although the problem is daunting, and the magnitude of each individual's efforts may be indistinguishable in a mainstem stream, we may be able to detect incremental improvements earlier within a sub-watershed. In Seven Mile Creek, a small watershed in south-central Minnesota, we monitored at the sub-watershed scale to search for evidence of intermediate improvements during a years-long effort to reduce nutrient and sediment loads. The watershed is 9300 hectares with approximately 95% committed to corn and soybeans. Subwatershed 1 (SW1) is 4030 hectares and subwatershed 2 (SW2) is 3690 hectares (43% and 40% of the watershed area, respectively). In both subwatersheds, ubiquitous subsurface drain tile quickly drains water from the land, shunting it into tributaries and the mainstem which then have flashy storm responses. In 2016-2017, the two subwatersheds differed in water quality and storm response, despite nearly identical size, topography, climate, and geology. For example, during large storm events in 2016, total suspended sediment (TSS) concentrations were measured as high as 113 mg L-1 in subwatershed 1 and 79 mg L-1 in subwatershed 2. However, the annual average TSS concentration was 2 mg L-1 in SW1 and 3 mg L-1 in SW2, resulting in a higher loading from SW2. In contrast, the annual average nitrate concentration was higher in SW1 than SW2 (28 mg L-1 and 20 mg L-1, respectively). We determined that the difference is likely due to differences in soil type, cropping practices, or recent best management practice (BMP) implementation. While a few landowners have taken substantial actions to implement BMPs, others remain skeptical about the sources of and potential solutions for pollution in this creek. In SW1 there has been more effective management of water flow and sediment mobilization, while in SW2 nitrate is the success story. This message can be delivered to landowners in both subwatersheds as evidence that individual actions are creating positive change. Previous experience indicates that this landowner "buy-in" and peer-to-peer conversation will be the most effective at initiating and sustaining better land management.

Energy Efficient Probabilistic Broadcasting for Mobile Ad-Hoc Network

NASA Astrophysics Data System (ADS)

Kumar, Sumit; Mehfuz, Shabana

2017-06-01

In mobile ad-hoc network (MANETs) flooding method is used for broadcasting route request (RREQ) packet from one node to another node for route discovery. This is the simplest method of broadcasting of RREQ packets but it often results in broadcast storm problem, originating collisions and congestion of packets in the network. A probabilistic broadcasting is one of the widely used broadcasting scheme for route discovery in MANETs and provides solution for broadcasting storm problem. But it does not consider limited energy of the battery of the nodes. In this paper, a new energy efficient probabilistic broadcasting (EEPB) is proposed in which probability of broadcasting RREQs is calculated with respect to remaining energy of nodes. The analysis of simulation results clearly indicate that an EEPB route discovery scheme in ad-hoc on demand distance vector (AODV) can increase the network lifetime with a decrease in the average power consumption and RREQ packet overhead. It also decreases the number of dropped packets in the network, in comparison to other EEPB schemes like energy constraint gossip (ECG), energy aware gossip (EAG), energy based gossip (EBG) and network lifetime through energy efficient broadcast gossip (NEBG).

Reconstructed storm tracks reveal three centuries of changing moisture delivery to North America

PubMed Central

Wise, Erika K.; Dannenberg, Matthew P.

2017-01-01

Moisture delivery to western North America is closely linked to variability in the westerly storm tracks of midlatitude cyclones, which are, in turn, modified by larger-scale features such as the El Niño–Southern Oscillation system. Instrumental and modeling data suggest that extratropical storm tracks may be intensifying and shifting poleward due to anthropogenic climate change, but it is difficult to separate recent trends from natural variability because of the large amount of decadal and longer variation in storm tracks and their limited instrumental record. We reconstruct cool-season, midlatitude Pacific storm-track position and intensity from 1693 to 1995 CE using existing tree-ring chronologies along with a network of newly developed chronologies from the U.S. Pacific Northwest, where small variations in storm-track position can have a major influence on hydroclimate patterns. Our results show high interannual-to-multidecadal variability in storm-track position and intensity over the past 303 years, with spectral signatures characteristic of tropical and northern Pacific influences. Comparison with reconstructions of precipitation and tropical sea surface temperature confirms the relationship between shifting drought patterns in the Pacific Northwest and storm-track variability through time and demonstrates the long-term influence of El Niño. These results allow us to place recent storm-track changes in the context of decadal and multidecadal fluctuations across the long-term record, showing that recent changes in storm-track intensity likely represent a warming-related increase amplified by natural decadal variability. PMID:28630900

Reconstructed storm tracks reveal three centuries of changing moisture delivery to North America.

PubMed

Wise, Erika K; Dannenberg, Matthew P

2017-06-01

Moisture delivery to western North America is closely linked to variability in the westerly storm tracks of midlatitude cyclones, which are, in turn, modified by larger-scale features such as the El Niño-Southern Oscillation system. Instrumental and modeling data suggest that extratropical storm tracks may be intensifying and shifting poleward due to anthropogenic climate change, but it is difficult to separate recent trends from natural variability because of the large amount of decadal and longer variation in storm tracks and their limited instrumental record. We reconstruct cool-season, midlatitude Pacific storm-track position and intensity from 1693 to 1995 CE using existing tree-ring chronologies along with a network of newly developed chronologies from the U.S. Pacific Northwest, where small variations in storm-track position can have a major influence on hydroclimate patterns. Our results show high interannual-to-multidecadal variability in storm-track position and intensity over the past 303 years, with spectral signatures characteristic of tropical and northern Pacific influences. Comparison with reconstructions of precipitation and tropical sea surface temperature confirms the relationship between shifting drought patterns in the Pacific Northwest and storm-track variability through time and demonstrates the long-term influence of El Niño. These results allow us to place recent storm-track changes in the context of decadal and multidecadal fluctuations across the long-term record, showing that recent changes in storm-track intensity likely represent a warming-related increase amplified by natural decadal variability.

Super-Resolution Fluorescence Imaging of Spatial Organization of Proteins and Lipids in Natural Rubber.

PubMed

Wu, Jinrong; Qu, Wei; Huang, Guangsu; Wang, Siyuan; Huang, Cheng; Liu, Han

2017-06-12

Natural rubber (NR) with proteins and lipids has superior mechanical properties to its synthetic counterpart, polyisoprene rubber. However, it is a challenge to unravel the morphology of proteins and lipids. Here we used two-color stochastic optical reconstruction microscopy (STORM) to directly visualize the spatial organization of proteins and lipids in NR. We found that the proteins and lipids form an interdispersed stabilizing layer on the surface of NR latex particles. After drying, the proteins and lipids form aggregates of up to 300 nm in diameter. The aggregates physically interact with the terminal groups of polyisoprene chains, leading to the formation of a network, which contributes to the high elasticity and mechanical property of NR. If we remove proteins in NR, the large phospholipid aggregates disintegrate into small ones. However, it does not decompose the network but rather reduces the effective cross-linking density, thus the deproteinized NR is still elastic-like with decreased mechanical property. Removing both proteins and lipids wholly decomposes the network, thus, results in a liquid-like behavior of the rubber. The STORM measurements in this paper enable more insight into the structure-property relationship of NR, which also shows a great potential of STORM in studying the fine structure of polymeric materials and nanocomposites.

A global scale picture of ionospheric peak electron density changes during geomagnetic storms

NASA Astrophysics Data System (ADS)

Kumar, Vickal V.; Parkinson, Murray L.

2017-04-01

Changes in ionospheric plasma densities can affect society more than ever because of our increasing reliance on communication, surveillance, navigation, and timing technology. Models struggle to predict changes in ionospheric densities at nearly all temporal and spatial scales, especially during geomagnetic storms. Here we combine a 50 year (1965-2015) geomagnetic disturbance storm time (Dst) index with plasma density measurements from a worldwide network of 132 vertical incidence ionosondes to develop a picture of global scale changes in peak plasma density due to geomagnetic storms. Vertical incidence ionosondes provide measurements of the critical frequency of the ionospheric F2 layer (foF2), a direct measure of the peak electron density (NmF2) of the ionosphere. By dissecting the NmF2 perturbations with respect to the local time at storm onset, season, and storm intensity, it is found that (i) the storm-associated depletions (negative storm effects) and enhancements (positive storm effects) are driven by different but related physical mechanisms, and (ii) the depletion mechanism tends to dominate over the enhancement mechanism. The negative storm effects, which are detrimental to HF radio links, are found to start immediately after geomagnetic storm onset in the nightside high-latitude ionosphere. The depletions in the dayside high-latitude ionosphere are delayed by a few hours. The equatorward expansion of negative storm effects is found to be regulated by storm intensity (farthest equatorward and deepest during intense storms), season (largest in summer), and time of day (generally deeper on the nightside). In contrast, positive storm effects typically occur on the dayside midlatitude and low-latitude ionospheric regions when the storms are in the main phase, regardless of the season. Closer to the magnetic equator, moderate density enhancements last up to 40 h during the recovery phase of equinox storms, regardless of the local time. Strikingly, high-latitude plasma densities are moderately enhanced for up to 60 h prior to the actual onset of storms during the equinoxes and summer; a potential precursor of a geomagnetic storm.

Storm surge along the Pacific coast of North America

NASA Astrophysics Data System (ADS)

Bromirski, Peter D.; Flick, Reinhard E.; Miller, Arthur J.

2017-01-01

Storm surge is an important factor that contributes to coastal flooding and erosion. Storm surge magnitude along eastern North Pacific coasts results primarily from low sea level pressure (SLP). Thus, coastal regions where high surge occurs identify the dominant locations where intense storms make landfall, controlled by storm track across the North Pacific. Here storm surge variability along the Pacific coast of North America is characterized by positive nontide residuals at a network of tide gauge stations from southern California to Alaska. The magnitudes of mean and extreme storm surge generally increase from south to north, with typically high amplitude surge north of Cape Mendocino and lower surge to the south. Correlation of mode 1 nontide principal component (PC1) during winter months (December-February) with anomalous SLP over the northeast Pacific indicates that the dominant storm landfall region is along the Cascadia/British Columbia coast. Although empirical orthogonal function spatial patterns show substantial interannual variability, similar correlation patterns of nontide PC1 over the 1948-1975 and 1983-2014 epochs with anomalous SLP suggest that, when considering decadal-scale time periods, storm surge and associated tracks have generally not changed appreciably since 1948. Nontide PC1 is well correlated with PC1 of both anomalous SLP and modeled wave height near the tide gauge stations, reflecting the interrelationship between storms, surge, and waves. Weaker surge south of Cape Mendocino during the 2015-2016 El Niño compared with 1982-1983 may result from changes in Hadley circulation. Importantly from a coastal impacts perspective, extreme storm surge events are often accompanied by high waves.

Semiconducting carbon nanotube network thin-film transistors with enhanced inkjet-printed source and drain contact interfaces

NASA Astrophysics Data System (ADS)

Lee, Yongwoo; Yoon, Jinsu; Choi, Bongsik; Lee, Heesung; Park, Jinhee; Jeon, Minsu; Han, Jungmin; Lee, Jieun; Kim, Yeamin; Kim, Dae Hwan; Kim, Dong Myong; Choi, Sung-Jin

2017-10-01

Carbon nanotubes (CNTs) are emerging materials for semiconducting channels in high-performance thin-film transistor (TFT) technology. However, there are concerns regarding the contact resistance (Rcontact) in CNT-TFTs, which limits the ultimate performance, especially the CNT-TFTs with the inkjet-printed source/drain (S/D) electrodes. Thus, the contact interfaces comprising the overlap between CNTs and metal S/D electrodes play a particularly dominant role in determining the performances and degree of variability in the CNT-TFTs with inkjet-printed S/D electrodes. In this work, the CNT-TFTs with improved device performance are demonstrated to enhance contact interfaces by controlling the CNT density at the network channel and underneath the inkjet-printed S/D electrodes during the formation of a CNT network channel. The origin of the improved device performance was systematically investigated by extracting Rcontact in the CNT-TFTs with the enhanced contact interfaces by depositing a high density of CNTs underneath the S/D electrodes, resulting in a 59% reduction in Rcontact; hence, the key performance metrics were correspondingly improved without sacrificing any other device metrics.

San Francisco Bay Area Baseline Trash Loading Summary Results for all counties

EPA Pesticide Factsheets

The San Francisco Bay Area stormwater permit sets trash control guidelines for discharges through the storm drain system. The permit covers Alameda, Contra Costa, Santa Clara, and San Mateo counties and the cities of Vallejo, Fairfield, and Suisun City. By February 2012 the permittees must provide a baseline trash load estimate, a list of trash hotspots targeted for annual cleanup, and an implementation plan for best management practices to meet trash reduction milestones over the next decade. A trash reduction crediting program will be used to account for best management practice effectiveness. The permit establishes goals for trash reduction beginning in 2014 and reaching a zero level by 2022.

Fluvial geomorphological response along the upland sediment cascade during the record-breaking December 2015 floods, Cumbria, UK

NASA Astrophysics Data System (ADS)

Russell, Andrew; Perks, Matthew; Large, Andrew; Dunning, Stuart; Warburton, Jeff

2016-04-01

Between 0900 GMT on 4th December and 0900 GMT on 6th December 2015, Atlantic Storm Desmond produced over 260 mm of rainfall in Cumbria, northwest England, representing a new UK 48 hour rainfall maximum, and breaking previous records set in 2005 and 2009. The December 2015 event resulted in a number of rivers significantly exceeding their 2009 levels, over-topping recently-commissioned flood defences, destroying bridges and flooding thousands of homes. Our research aim is to identify factors controlling significant geomorphological and sedimentary response during Storm Desmond along the upland sediment cascade including: Rattling Beck (Glenridding), a high gradient upland stream draining the flanks of Helvellyn (950 m.a.o.d.), and a 25km extended reach of the lower gradient piedmont Derwent River corridor downstream of Bassenthwaite Lake. Rattling Beck descends steeply from the eastern slopes of the Helvellyn massif draining across an alluvial fan into Lake Ullswater. On 5th December 2015 the village of Glenridding was severely impacted by flooding which deposited boulder-sized sediment within the centre of the village, completely blocking the pre-existing stream course and causing avulsion of waning stage flows through riverside properties. A major new sediment lobe was deposited on the existing alluvial fan downstream of the village, grading to the temporarily raised lake water level. Although a number of hillslope failures occurred in the higher catchment, the majority of the sediment transported by Rattling Beck and impacting the village was acquired within a 2km reach upstream of Glenridding through erosion of older glacial and alluvial sediments. Lateral channel erosion was enhanced by inability of flood flows to rework highly resistant boulder bar lag deposits related to a previous mine tailings dam failure in 1927. The River Derwent corridor extends for 30km downstream of Bassenthwaite Lake to the Irish Sea at Workington and has a sinuous course ranging in maximum width from 500m to <150m in reaches narrowed by human modification. Despite the Derwent's relatively low gradient, significant erosional and depositional impacts occurred as a result of Storm Desmond, often reactivating discrete areas along the river corridor that saw major sediment shift and channel alteration in the 2009 floods. 2015 channel avulsions are associated with floodplain erosion principally initiated by the ploughing of, and scour around, large woody debris. Large gravel sheets (< 0.5 km2) characterised by distal slip faces up to 1m high were deposited at river corridor expansions downstream of actively eroding hillslopes and artificially narrowed reaches. Overall, major geomorphological response to Storm Desmond floods in Rattling Beck and the River Derwent is seen to be amplified by centennial-scale human modifications to river corridors and alluvial fans. River corridor engineering on the River Derwent and village construction on Rattling Beck's depositional fan at Glenridding moved both systems out of their natural equilibrium exacerbating the effects of storm-generated flooding on the Derwent (2009, 2015) and Rattling Beck (2015).

A Multiple-Tracer Approach for Identifying Sewage Sources to an Urban Stream System

USGS Publications Warehouse

Hyer, Kenneth Edward

2007-01-01

The presence of human-derived fecal coliform bacteria (sewage) in streams and rivers is recognized as a human health hazard. The source of these human-derived bacteria, however, is often difficult to identify and eliminate, because sewage can be delivered to streams through a variety of mechanisms, such as leaking sanitary sewers or private lateral lines, cross-connected pipes, straight pipes, sewer-line overflows, illicit dumping of septic waste, and vagrancy. A multiple-tracer study was conducted to identify site-specific sources of sewage in Accotink Creek, an urban stream in Fairfax County, Virginia, that is listed on the Commonwealth's priority list of impaired streams for violations of the fecal coliform bacteria standard. Beyond developing this multiple-tracer approach for locating sources of sewage inputs to Accotink Creek, the second objective of the study was to demonstrate how the multiple-tracer approach can be applied to other streams affected by sewage sources. The tracers used in this study were separated into indicator tracers, which are relatively simple and inexpensive to apply, and confirmatory tracers, which are relatively difficult and expensive to analyze. Indicator tracers include fecal coliform bacteria, surfactants, boron, chloride, chloride/bromide ratio, specific conductance, dissolved oxygen, turbidity, and water temperature. Confirmatory tracers include 13 organic compounds that are associated with human waste, including caffeine, cotinine, triclosan, a number of detergent metabolites, several fragrances, and several plasticizers. To identify sources of sewage to Accotink Creek, a detailed investigation of the Accotink Creek main channel, tributaries, and flowing storm drains was undertaken from 2001 to 2004. Sampling was conducted in a series of eight synoptic sampling events, each of which began at the most downstream site and extended upstream through the watershed and into the headwaters of each tributary. Using the synoptic sampling approach, 149 sites were sampled at least one time for indicator tracers; 52 of these sites also were sampled for confirmatory tracers at least one time. Through the analysis of multiple-tracer levels in the synoptic samples, three major sewage sources to the Accotink Creek stream network were identified, and several other minor sewage sources to the Accotink Creek system likely deserve additional investigation. Near the end of the synoptic sampling activities, three additional sampling methods were used to gain better understanding of the potential for sewage sources to the watershed. These additional sampling methods included optical brightener monitoring, intensive stream sampling using automated samplers, and additional sampling of several storm-drain networks. The samples obtained by these methods provided further understanding of possible sewage sources to the streams and a better understanding of the variability in the tracer concentrations at a given sampling site. Collectively, these additional sampling methods were a valuable complement to the synoptic sampling approach that was used for the bulk of this study. The study results provide an approach for local authorities to use in applying a relatively simple and inexpensive collection of tracers to locate sewage sources to streams. Although this multiple-tracer approach is effective in detecting sewage sources to streams, additional research is needed to better detect extremely low-volume sewage sources and better enable local authorities to identify the specific sources of the sewage once it is detected in a stream reach.

Using Smoke Injection in Drains to Identify Potential Preferential Pathways in a Drained Arable Field

NASA Astrophysics Data System (ADS)

Nielsen, M. H.; Petersen, C. T.; Hansen, S.

2014-12-01

Macropores forming a continuous pathway between the soil surface and subsurface drains favour the transport of many contaminants from agricultural fields to surface waters. The smoke injection method presented by Shipitalo and Gibbs (2000) used for demonstrating and quantifying such pathways has been further developed and used on a drained Danish sandy loam. In order to identify the preferential pathways to drains, smoke was injected in three 1.15 m deep tile drains (total drain length 93 m), and smoke emitting macropores (SEMP) at the soil surface were counted and characterized as producing either strong or weak plumes compared to reference plumes from 3 and 6 mm wide tubes. In the two situations investigated in the present study - an early spring and an autumn situation, smoke only penetrated the soil surface layer via earthworm burrows located in a 1.0 m wide belt directly above the drain lines. However, it is known from previous studies that desiccation fractures in a dry summer situation also can contribute to the smoke pattern. The distance between SEMP measured along the drain lines was on average 0.46 m whereas the average spacing between SEMP with strong plumes was 2.3 m. Ponded water was applied in 6 cm wide rings placed above 52 burrows including 17 reference burrows which did not emit smoke. Thirteen pathways in the soil were examined using dye tracer and profile excavation. SEMP with strong plumes marked the entrance of highly efficient transport pathways conducting surface applied water and dye tracer into the drain. However, no single burrow was traced all the way from the surface into the drain, the dye patterns branched off in a network of other macropores. Water infiltration rates were significantly higher (P < 0.05) in SEMP with strong plumes (average rate: 247 mL min-1 n = 19) compared to SEMP with weak plumes (average rate: 87 mL min-1 n = 16) and no plumes (average rate: 56 mL min-1 n = 17). The results suggest that the smoke injection method is useful for identification of potentially efficient pathways for surface applied contaminants to drains and surface waters, pathways being associated primarily with unevenly distributed SEMP producing strong smoke plumes.

Monitoring Inland Storm Surge and Flooding from Hurricane Rita

USGS Publications Warehouse

McGee, Benton D.; Tollett, Roland W.; Mason, Jr., Robert R.

2006-01-01

Pressure transducers (sensors) and high-water marks were used to document the inland water levels related to storm surge generated by Hurricane Rita in southwestern Louisiana and southeastern Texas. On September 22-23, 2005, an experimental monitoring network of sensors was deployed at 33 sites over an area of about 4,000 square miles to record the timing, extent, and magnitude of inland hurricane storm surge and coastal flooding. Sensors were programmed to record date and time, temperature, and barometric or water pressure. Water pressure was corrected for changes in barometric pressure and salinity. Elevation surveys using global-positioning systems and differential levels were used to relate all storm-surge water-level data, reference marks, benchmarks, sensor measuring points, and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). The resulting data indicated that storm-surge water levels over 14 feet above NAVD 88 occurred at three locations, and rates of water-level rise greater than 5 feet per hour occurred at three locations near the Louisiana coast.

(abstract) Using GPS Measurements to Identify Global Ionospheric Storms in Near Real-Time

NASA Technical Reports Server (NTRS)

Ho, C. M.; Mannucci, A. J.; Lindqwister, U. J.; Rao, A. M.; Pi, X.; Wilson, B. D.; Yuan, D. N.; Reyes, M.

1996-01-01

The solar wind interacts with the Earth's magnetosphere, eventually dissipating energy into the ionosphere and atmosphere. As a terminator, the ionosphere responds to magnetic storms, which is very important in understanding the energy coupling process between the Sun and the Earth and in forecasting space weather changes.The worldwide GPS network, for the first time, makes near real-time global ionospheric TEC measurements a possibility. Based on these measurements, global ionospheric TEC maps are generated with time resolution of from 5 minutes to hours. Using these maps, we can analyze the global evolution of ionospheric storms on temporal and spatial scales, which have been dificult to study before. We find that for certain types of storms (such as TID-driven), it is possible to identify them near onset and issue warning signals during the early stages. Main attention has been paid on northern hemispheric winter storms. Their common features and physical mechanisms are being investigated.

Final Environmental Assessment Airfield Storm Drainage System Repair Joint Base Andrews-Naval Air Facility Washington, MD

DTIC Science & Technology

2015-06-01

sediment control plan during project implementation would be expected to minimize any adverse effects on resident fish species during construction. In... Effective August 8, 2007, under the authority of the Endangered Species Act of 1973, as amended, the U.S. Fish and Wildlife Service (Service) removed...of storm sewer pipe and 122 manholes of the airfield stormwater drainage network. Summary of Anticipated Environmental Effects Associated with the

Impacts of logging on storm peak flows, flow volumes and suspended sediment loads in Caspar Creek, California

Treesearch

Jack Lewis; Sylvia R. Mori; Elizabeth T. Keppeler; Robert R. Ziemer

2001-01-01

Abstract - Models are fit to 11 years of storm peak flows, flow volumes, and suspended sediment loads on a network of 14 stream gaging stations in the North Fork Caspar Creek, a 473-ha coastal watershed bearing a second-growth forest of redwood and Douglas-fir. For the first 4 years of monitoring, the watershed was in a relatively undisturbed state, having last been...

Differentiating littering, urban runoff and marine transport as sources of marine debris in coastal and estuarine environments

PubMed Central

Willis, Kathryn; Denise Hardesty, Britta; Kriwoken, Lorne; Wilcox, Chris

2017-01-01

Marine debris is a burgeoning global issue with economic, ecological and aesthetic impacts. While there are many studies now addressing this topic, the influence of urbanisation factors such as local population density, stormwater drains and roads on the distribution of coastal litter remains poorly understood. To address this knowledge gap, we carried out standardized surveys at 224 transect surveys at 67 sites in two estuaries and along the open coast in Tasmania, Australia. We explored the relative support for three hypotheses regarding the sources of the debris; direct deposition by beachgoers, transport from surrounding areas via storm water drains and coastal runoff, and onshore transport from the marine system. We found strong support for all three mechanisms, however, onshore transport from the marine reservoir was the most important mechanism. Overall, the three models together explained 45.8 percent of the variation in our observations. Our results also suggest that most debris released into the marine environment is deposited locally, which may be the answer to where all the missing plastic is in the ocean. Furthermore, local interventions are likely to be most effective in reducing land-based inputs into the ocean. PMID:28281667

Differentiating littering, urban runoff and marine transport as sources of marine debris in coastal and estuarine environments

NASA Astrophysics Data System (ADS)

Willis, Kathryn; Denise Hardesty, Britta; Kriwoken, Lorne; Wilcox, Chris

2017-03-01

Marine debris is a burgeoning global issue with economic, ecological and aesthetic impacts. While there are many studies now addressing this topic, the influence of urbanisation factors such as local population density, stormwater drains and roads on the distribution of coastal litter remains poorly understood. To address this knowledge gap, we carried out standardized surveys at 224 transect surveys at 67 sites in two estuaries and along the open coast in Tasmania, Australia. We explored the relative support for three hypotheses regarding the sources of the debris; direct deposition by beachgoers, transport from surrounding areas via storm water drains and coastal runoff, and onshore transport from the marine system. We found strong support for all three mechanisms, however, onshore transport from the marine reservoir was the most important mechanism. Overall, the three models together explained 45.8 percent of the variation in our observations. Our results also suggest that most debris released into the marine environment is deposited locally, which may be the answer to where all the missing plastic is in the ocean. Furthermore, local interventions are likely to be most effective in reducing land-based inputs into the ocean.

A Bayesian Network to Predict Barrier Island Geomorphologic Characteristics

NASA Astrophysics Data System (ADS)

Gutierrez, B.; Plant, N. G.; Thieler, E. R.; Turecek, A.; Stippa, S.

2014-12-01

Understanding how barrier islands along the Atlantic and Gulf coasts of the United States respond to storms and sea-level rise is an important management concern. Although these threats are well recognized, quantifying the integrated vulnerability is challenging due to the range of time and space scalesover which these processes act. Developing datasets and methods to identify the physical vulnerabilities of coastal environments due to storms and sea-level rise thus is an important scientific focus that supports land management decision making. Here we employ a Bayesian Network (BN) to model the interactions between geomorphic variables sampled from existing datasets that capture both storm-and sea-level rise related coastal evolution. The BN provides a means of estimating probabilities of changes in specific geomorphic characteristics such as foredune crest height, beach width, beach height, given knowledge of barrier island width, maximum barrier island elevation, distance from an inlet, the presence of anthropogenic modifications, and long-term shoreline change rates, which we assume to be directly related to sea-level rise. We evaluate BN skill and explore how different constraints, such as shoreline change characteristics (eroding, stable, accreting), distance to nearby inlets and island width, affect the probability distributions of future morphological characteristics. Our work demonstrates that a skillful BN can be constructed and that factors such as distance to inlet, shoreline change rate, and the presence of human alterations have the strongest influences on network performance. For Assateague Island, Maryland/Virginia, USA, we find that different shoreline change behaviors affect the probabilities of specific geomorphic characteristics, such as dune height, which allows us to identify vulnerable locations on the barrier island where habitat or infrastructure may be vulnerable to storms and sea-level rise.

Classification of Snowfall Events and Their Effect on Canopy Interception Efficiency in a Temperate Montane Forest.

NASA Astrophysics Data System (ADS)

Roth, T. R.; Nolin, A. W.

2015-12-01

Forest canopies intercept as much as 60% of snowfall in maritime environments, while processes of sublimation and melt can reduce the amount of snow transferred from the canopy to the ground. This research examines canopy interception efficiency (CIE) as a function of forest and event-scale snowfall characteristics. We use a 4-year dataset of continuous meteorological measurements and monthly snow surveys from the Forest Elevation Snow Transect (ForEST) network that has forested and open sites at three elevations spanning the rain-snow transition zone to the upper seasonal snow zone. Over 150 individual storms were classified by forest and storm type characteristics (e.g. forest density, vegetation type, air temperature, snowfall amount, storm duration, wind speed, and storm direction). The between-site comparisons showed that, as expected, CIE was highest for the lower elevation (warmer) sites with higher forest density compared with the higher elevation sites where storm temperatures were colder, trees were smaller and forests were less dense. Within-site comparisons based on storm type show that this classification system can be used to predict CIE.Our results suggest that the coupling of forest type and storm type information can improve estimates of canopy interception. Understanding the effects of temperature and storm type in temperate montane forests is also valuable for future estimates of canopy interception under a warming climate.

An Ionospheric Index Model based on Linear Regression and Neural Network Approaches

NASA Astrophysics Data System (ADS)

Tshisaphungo, Mpho; McKinnell, Lee-Anne; Bosco Habarulema, John

2017-04-01

The ionosphere is well known to reflect radio wave signals in the high frequency (HF) band due to the present of electron and ions within the region. To optimise the use of long distance HF communications, it is important to understand the drivers of ionospheric storms and accurately predict the propagation conditions especially during disturbed days. This paper presents the development of an ionospheric storm-time index over the South African region for the application of HF communication users. The model will result into a valuable tool to measure the complex ionospheric behaviour in an operational space weather monitoring and forecasting environment. The development of an ionospheric storm-time index is based on a single ionosonde station data over Grahamstown (33.3°S,26.5°E), South Africa. Critical frequency of the F2 layer (foF2) measurements for a period 1996-2014 were considered for this study. The model was developed based on linear regression and neural network approaches. In this talk validation results for low, medium and high solar activity periods will be discussed to demonstrate model's performance.

A Bandwidth-Efficient Dissemination Scheme of Non-Safety Information in Urban VANETs †

PubMed Central

Garcia-Lozano, Estrella; Campo, Celeste; Garcia-Rubio, Carlos; Rodriguez-Carrion, Alicia

2016-01-01

The recent release of standards for vehicular communications will hasten the development of smart cities in the following years. Many applications for vehicular networks, such as blocked road warnings or advertising, will require multi-hop dissemination of information to all vehicles in a region of interest. However, these networks present special features and difficulties that may require special measures. The dissemination of information may cause broadcast storms. Urban scenarios are especially sensitive to broadcast storms because of the high density of vehicles in downtown areas. They also present numerous crossroads and signal blocking due to buildings, which make dissemination more difficult than in open, almost straight interurban roadways. In this article, we discuss several options to avoid the broadcast storm problem while trying to achieve the maximum coverage of the region of interest. Specifically, we evaluate through simulations different ways to detect and take advantage of intersections and a strategy based on store-carry-forward to overcome short disconnections between groups of vehicles. Our conclusions are varied, and we propose two different solutions, depending on the requirements of the application. PMID:27355956

A Bandwidth-Efficient Dissemination Scheme of Non-Safety Information in Urban VANETs.

PubMed

Garcia-Lozano, Estrella; Campo, Celeste; Garcia-Rubio, Carlos; Rodriguez-Carrion, Alicia

2016-06-27

The recent release of standards for vehicular communications will hasten the development of smart cities in the following years. Many applications for vehicular networks, such as blocked road warnings or advertising, will require multi-hop dissemination of information to all vehicles in a region of interest. However, these networks present special features and difficulties that may require special measures. The dissemination of information may cause broadcast storms. Urban scenarios are especially sensitive to broadcast storms because of the high density of vehicles in downtown areas. They also present numerous crossroads and signal blocking due to buildings, which make dissemination more difficult than in open, almost straight interurban roadways. In this article, we discuss several options to avoid the broadcast storm problem while trying to achieve the maximum coverage of the region of interest. Specifically, we evaluate through simulations different ways to detect and take advantage of intersections and a strategy based on store-carry-forward to overcome short disconnections between groups of vehicles. Our conclusions are varied, and we propose two different solutions, depending on the requirements of the application.

Impacts of fertilization on water quality of a drained pine plantation: a worst case scenario.

PubMed

Beltran, Bray J; Amatya, Devendra M; Youssef, Mohamed; Jones, Martin; Callahan, Timothy J; Skaggs, R Wayne; Nettles, Jami E

2010-01-01

Intensive plantation forestry will be increasingly important in the next 50 yr to meet the high demand for domestic wood in the United States. However, forest management practices can substantially influence downstream water quality and ecology. This study analyses, the effect of fertilization on effluent water quality of a low gradient drained coastal pine plantation in Carteret County, North Carolina using a paired watershed approach. The plantation consists of three watersheds, two mature (31-yr) and one young (8-yr) (age at treatment). One of the mature watersheds was commercially thinned in 2002. The mature unthinned watershed was designated as the control. The young and mature-thinned watersheds were fertilized at different rates with Arborite (Encee Chemical Sales, Inc., Bridgeton, NC), and boron. The outflow rates and nutrient concentrations in water drained from each of the watersheds were measured. Nutrient concentrations and loadings were analyzed using general linear models (GLM). Three large storm events occurred within 47 d of fertilization, which provided a worst case scenario for nutrient export from these watersheds to the receiving surface waters. Results showed that average nutrient concentrations soon after fertilization were significantly (alpha = 0.05) higher on both treatment watersheds than during any other period during the study. This increase in nutrient export was short lived and nutrient concentrations and loadings were back to prefertilization levels as soon as 3 mo after fertilization. Additionally, the mature-thinned watershed presented higher average nutrient concentrations and loadings when compared to the young watershed, which received a reduced fertilizer rate than the mature-thinned watershed.

Facing Facebook: A Guide for Nonteens

ERIC Educational Resources Information Center

Siegle, Del

2011-01-01

Facebook is a social networking phenomenon that has taken the United States by storm and gained universal popularity. Facebook has more than one-half trillion members; 1 out of every 12 people on the planet has a Facebook account. Some argue the interactive nature of social networking sites (SNSs) such as Facebook, as well as other interactive…

Recent Responses of Western North American Forests and Hydroclimate to Pacific Storm Track Position and Intensity

NASA Astrophysics Data System (ADS)

Dannenberg, M. P.; Wise, E.

2017-12-01

Much of the precipitation delivered to western North America arrives during the October to March cool season via midlatitude Pacific storm tracks, which may shift in the future due to climate change. Using historical climate, tree-ring, and remote sensing data, we assessed the sensitivity of western North American hydroclimate and ecosystems to the position and intensity of cool-season Pacific storm tracks. From 1980-2014, mean annual cool-season storm tracks entered western North America between approximately 41°N to 53°N, with substantial interannual variability in both the position and intensity of the storm tracks. We examined relationships between storm tracks and two hydroclimatic variables: the cool-season standardized precipitation-evapotranspiration index and April snow water equivalent. We also assessed how historical storm track variability affected ecosystems using forest growth estimates from a large tree-ring network as well as land surface phenology and wildfire estimates from AVHRR and Landsat, respectively. Cool-season moisture supply and snowpack responded strongly to storm track position, with positive correlations to storm track latitude in eastern Alaska and northwestern Canada but negative correlations in the northwestern U.S. These hydroclimatic impacts were largely driven by the latitudinal position of storm tracks during the "shoulder" seasons (i.e., autumn and early spring). Ecosystems of the western U.S. tended to be greener and more productive following winters with south-shifted storm tracks, while Canadian ecosystems were greener in years when the cool-season storm track was shifted to the north. On average, larger areas of the northwestern U.S. were burned by moderate to high severity wildfires when storm tracks were displaced north, and the average burn area per fire also tended to be higher in years with north-shifted storm tracks. Assuming that these historical relationships continue to hold under future climate scenarios, our results suggest that projected long-term shifts of Pacific storm tracks over the 21st century would likely alter hydroclimatic and ecological regimes in western North America, particularly in the northwestern U.S., where moisture supply and ecosystem processes are highly sensitive to the position of cool-season storm tracks.

Flooding in Clark and Lincoln Counties, Nevada, December 2004 and January 2005

USGS Publications Warehouse

Ryan, Roslyn

2006-01-01

Introduction: A regional storm passed through the Las Vegas Valley, Nevada, on December 28-29, 2004, producing up to 2 inches of rain in a 24-hour period. Due to the intense, sustained rainfall, streamflow along Las Vegas Wash was near the record discharges of July 8, 1999. Additional rainfall in December and in January, combined with an early warming trend, resulted in record flooding along Meadow Valley Wash, Muddy River, and Virgin River, January 10-11, 2005 (figs. 1 and 2). On January 7, this warming trend resulted in about a 15?F (degree Fahrenheit) increase over the previous week (fig. 2). This temperature spike, along with further precipitation, caused much of the snow pack in the surrounding mountain ranges to melt and run off into the valleys. These two factors led to the major flood events in Clark and Lincoln Counties during December 2004 and January 2005. Total flood and storm damage for Lincoln County was estimated at $9.4 million and $4.5 million for Clark County (Manning, 2005). Clark County generally is drained by the Las Vegas and Meadow Valley Washes, and the Muddy and Virgin River systems. Las Vegas Valley is drained by Duck Creek, Tropicana Wash (not in fig. 1), Flamingo Wash, Las Vegas Wash, and several smaller tributaries (fig. 1). Water in these drainages generally flows eastward through Las Vegas to Las Vegas Wash and on toward Lake Mead, an impoundment of the Colorado River. The Virgin River originates in southern Utah, flows past Littlefield, AZ, through Mesquite, NV, and into the Overton Arm of Lake Mead. Meadow Valley Wash flows from Ursine, NV, through Caliente, NV, continues southeast through Moapa Valley, and into the Muddy River at Glendale, NV. The Muddy River flows southeast through Moapa Valley into the Overton Arm of Lake Mead (Kane and Wilson, 2000).

Reconnaissance of toxic substances in the Jordan River, Salt Lake County, Utah

USGS Publications Warehouse

Thompson, Kendall R.

1984-01-01

A reconnaissance of toxic substances in the Jordan River, Salt Lake County, Utah, was made during July, 1980 to October, 1982 as part of a larger study of the river that included studies of sanitary quality, dissolved oxygen, and turbidity. Samples for toxic substances were collected at five sites on the Jordan River, at three major tributaries, and at six storm drains. The toxic substance that most frequently exceeded State standards was total mercury. About 78 percent of the 138 samples for total mercury exceeded the State standard of 0.05 microgram per liter. Other toxic substances that exceeded State standards were: Ammonia-18 percent of the samples analyzed, cadmium--9 percent, copper-9 percent, zinc--6 percent, and lead--2 percent. One sample for cyanide and one for iron also exceeded State standards. The diversity of toxic substances with concentrations large enough to cause them to be problems increased from the upstream sampling site at the Jordan Narrows to the next two downstream sites at 9000 South and 5800 South Streets. Concentrations of trace elements in stream-bottom materials also increased in a downstream direction. Substantial increases first were observed at 5800 South Street, and they were sustained throughout the downstream study area. Iron is transported in the greatest quantity of all the trace elements studied, with a mean load of 110 pounds per day. Notable loads of barium, boron, lead , and zinc also are transported by the river. DDD, DDE, DDT, dieldrin, heptachlor, methoxychlor, PCB, and 2,4-D were detected in bottom materials; and DDE, Silvex, and 2,4-D were detected in water samples. Of 112 organic compounds in the Environmental Protection Agency 's priority pollutant list, only chloroform was detected in the storm drains that empty into the Joran River. Several metals and phenol also were detected in the samples for priority pollutants. (USGS)

Calculating realistic voltages across the US power grid utilizing measured impedances and magnetic fields

NASA Astrophysics Data System (ADS)

Lucas, G.; Love, J. J.; Kelbert, A.; Bedrosian, P.; Rigler, E. J.

2017-12-01

Space weather induces significant geoelectric fields within Earth's subsurface that can adversely affect electric power grids. The complex interaction between space weather and the solid Earth has traditionally been approached with the use of simple 1-D impedance functions relating the inducing magnetic field to the induced geoelectric field. Ongoing data collection through the NSF EarthScope program has produced measured impedance data across much of the continental US. In this work, impedance data are convolved with magnetic field variations, obtained from USGS magnetic observatories, during a geomagnetic storm. This convolution produces geoelectric fields within the earth. These geoelectric fields are then integrated across power transmission lines to determine the voltage generated within each power line as a function of time during a geomagnetic storm. The voltages generated within the electric power grid will be shown for several historic geomagnetic storms. The estimated voltages calculated from 1-D and 3-D impedances differ by more than 100 V across some transmission lines. In combination with grounding resistance data and network topology, these voltage estimates can be utilized by power companies to estimate geomagnetically-induced currents throughout the network. These voltage estimates can provide information on which power lines are most vulnerable to geomagnetic storms, and assist power grid companies investigating where to install additional protections within their grid.

Design and routing of storm flows in an urbanized watershed without surface streams

NASA Astrophysics Data System (ADS)

Schaad, David E.; Farley, Jon; Haynes, Criss

2009-09-01

SummaryIn the karst geologic setting of Greenbrier County, West Virginia, USA, the drainage network in the watersheds do not support surface streams, but depend entirely on sinkholes, solution cavities, or injection wells as discharge points for accumulated storm water. By providing a systematic framework for designing and routing storms in this geologic setting, functioning retention and attenuation structures have been developed which are protective of water quality while still safely discharging storm water in a controlled manner to the subsurface. This article provides a rationale for the design methodology and then examines the successful implementation of an attenuation and storm water retention design to manage the surface discharges for an entire watershed. By examining the pre-development flows and evaluating future land use patterns (i.e., installation of impermeable surfaces over large areas), as well as sinkhole conveyance capabilities, it was necessary to examine alternative disposal options for collected storm water as well as devise a basin-wide management strategy to coordinate future development of the watershed. Additionally, innovative water quality measures were implemented to help prevent contamination from preferentially infiltrating into the subsurface as a result of these land development activities.

Strategic Downsizing and Learning Organisations.

ERIC Educational Resources Information Center

Griggs, Harvey E.; Hyland, Paul

2003-01-01

Downsizing or brain drain may damage the learning capacity of organizations. A case study of an aerospace manufacturing firm shows that appropriate strategies to analyze the impact on formal and informal learning networks may help manage or minimize the damage. (Contains 55 references.) (SK)

Generation of sedimentary fabrics and facies by repetitive excavation and storm infilling of burrow networks Holocene of south Florida and Caicos Platform, B. W. I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tedesco, L.P.; Wanless, H.R.

Excavation of deep, open burrow networks and subsequent infilling with sediment from the surface produces an entirely new sedimentary deposit and results in obliteration to severe diagenetic transformation of precursor depositional facies. Repetitive excavation and infilling is responsible for creating the preserved depositional facies of many marine deposits. Excavating burrowers occur from intertidal to abyssal depths, and are important throughout the Phanerozoic. The repetitive coupling of deep, open burrow excavation with subsequent storm sediment infilling of open burrow networks is a gradual process that ultimately results in the loss of the original deposit and the generation of new lithologies, fabricsmore » and facies. The new lithologies are produced in the subsurface and possess fabrics, textures and skeletal assemblages that are not a direct reflection of either precursor facies or the surficial depositional conditions. Sedimentary facies generated by repetitive burrow excavation and infilling commonly are massively bedded and generally are mottled skeletal packstones. Skeletal grains usually are well-preserved and coarser components are concentrated in burrow networks, pockets and patches. The coarse skeletal components of burrow-generated facies are a mixture of coarse bioclasts from the precursor facies and both the coarse and fine skeletal material introduced from the sediment surface. Many so-called bioturbated or massive facies may, in fact, be primary depositional facies generated in the subsurface and represent severe diagenetic transformation of originally deposited sequences. In addition, mudstones and wackestones mottled with packstone patches may record storm sedimentation.« less

Effects of tillage and application rate on atrazine transport to subsurface drainage: Evaluation of RZWQM using a six-year field study

USGS Publications Warehouse

Malone, Robert W.; Nolan, Bernard T.; Ma, Liwang; Kanwar, Rameshwar S.; Pederson, Carl H.; Heilman, Philip

2014-01-01

Well tested agricultural system models can improve our understanding of the water quality effects of management practices under different conditions. The Root Zone Water Quality Model (RZWQM) has been tested under a variety of conditions. However, the current model's ability to simulate pesticide transport to subsurface drain flow over a long term period under different tillage systems and application rates is not clear. Therefore, we calibrated and tested RZWQM using six years of data from Nashua, Iowa. In this experiment, atrazine was spring applied at 2.8 (1990–1992) and 0.6 kg/ha/yr (1993–1995) to two 0.4 ha plots with different tillage (till and no-till). The observed and simulated average annual flow weighted atrazine concentrations (FWAC) in subsurface drain flow from the no-till plot were 3.7 and 3.2 μg/L, respectively for the period with high atrazine application rates, and 0.8 and 0.9 μg/L, respectively for the period with low application rates. The 1990–1992 observed average annual FWAC difference between the no-till and tilled plot was 2.4 μg/L while the simulated difference was 2.1 μg/L. These observed and simulated differences for 1993–1995 were 0.1 and 0.1 μg/L, respectively. The Nash–Sutcliffe model performance statistic (EF) for cumulative atrazine flux to subsurface drain flow was 0.93 for the no-till plot testing years (1993–1995), which is comparable to other recent model tests. The value of EF is 1.0 when simulated data perfectly match observed data. The order of selected parameter sensitivity for RZWQM simulated FWAC was atrazine partition coefficient > number of macropores > atrazine half life in soil > soil hydraulic conductivity. Simulations from 1990 to 1995 with four different atrazine application rates applied at a constant rate throughout the simulation period showed concentrations in drain flow for the no-till plot to be twice those of the tilled plot. The differences were more pronounced in the early simulation period (1990–1992), partly because of the characteristics of macropore flow during large storms. The results suggest that RZWQM is a promising tool to study pesticide transport to subsurface drain flow under different tillage systems and application rates over several years, the concentrations of atrazine in drain flow can be higher with no-till than tilled soil over a range of atrazine application rates, and atrazine concentrations in drain flow are sensitive to the macropore flow characteristics under different tillage systems and rainfall timing and intensity.

Water-quality, biological, and habitat assessment of the Boeuf River Basin, southeastern Arkansas, 1994-96

USGS Publications Warehouse

Barks, C. Shane; Petersen, James C.; Usrey, Faron D.

2002-01-01

Water-quality and biological samples were collected at several sites in the Boeuf River Basin between November 1994 and December 1996. Water-quality and benthic macroinvertebrate community samples were collected and habitat was measured once at 25 ambient monitoring sites during periods of seasonal low flow. Water-quality storm-runoff samples were collected during 11 storm events at two sites (one draining a cotton field and one draining a forested area). Water-quality samples were collected at one site during the draining of a catfish pond. Water-quality samples from the 25 ambient sites indicate that streams in the Boeuf River Basin typically are turbid and nutrient enriched in late fall during periods of relatively low flow. Most suspended solids concentrations ranged from about 50 to 200 milligrams per liter (mg/L), most total nitrogen concentrations ranged from about 1.1 to 1.8 mg/L, and most total phosphorus concentrations ranged from about 0.25 to 0.40 mg/L. Suspended solids, total nitrogen, total ammonia plus organic nitrogen, total phosphorus, and dissolved orthophosphorus concentrations from samples collected during storm events were typically higher at the cotton field site than at the forested site. Estimated annual yields of suspended solids, nitrogen, and phosphorus were substantially higher from the cotton field than from the forested area. Dissolved chloride concentrations typically were higher at the forested site than from the cotton field site. Typically, the suspended solids and nutrient concentrations from the 25 ambient sites were lower than concentrations in runoff from the cotton field but higher than concentrations in runoff from the forest area. Concentrations of sulfate, chloride, suspended solids, and some nutrients in samples from the catfish pond generally were greater than concentrations in samples from other sites. Total phosphorus, orthophosphorus, and fecal coliform bacteria concentrations from the catfish pond generally were lower than concentrations in samples from other sites. Biological condition scores calculated using macroinvertebrate samples and U.S. Environmental Protection Agency Rapid Bioassessment Protocol II indicated that most of the 25 ambient sites would be in the 'moderately impaired' category. However, substantial uncertainty exists in this rating because bioassessment data were compared with data from a reference site outside of the Boeuf River Basin sampled using different methods. Several metrics indicated that communities at most of the ambient sites are composed of more tolerant macroinvertebrates than the community at the reference site. Habitat assessments (using Rapid Bioassessment Protocol II) indicated the reference site outside the Boeuf River Basin had better habitat than the ambient sites. Physical habitat scores for the 25 ambient sites indicated that most ambient sites had poor bottom substrate cover, embeddedness values, and flow and had poor to fair habitat related to most other factors. Most habitat factors at the reference site were considered good to excellent. Part of the variation in biological condition scores was explained by physical habitat scores and concentrations of suspended solids and dissolved oxygen. However, a considerable amount of variability in biological condition scores is not explained by these factors.

Modification of suburban carbon and nitrogen fluxes by a coupled channel/floodplain system assessed using in situ sensors

NASA Astrophysics Data System (ADS)

Wollheim, W. M.; Pellerin, B. A.; Saraceno, J.; Hopkinson, C.; Hope, A.; Morse, N.

2010-12-01

Biogeochemical fluxes in human dominated streams and rivers are highly impacted, but effects can be attenuated downstream through natural ecosystem processes. We deployed in situ nitrate, fdom, and chlorophyll sensors to characterize biogeochemical fluxes draining a suburban catchment, and modifications by a channel-floodplain system located immediately downstream. The upstream site reflects the suburban signal; the downstream site reflects the influence of the channel/floodplain on the suburban signal. FDOM showed a diurnal signal at both sites, but was stronger downstream, likely indicating new DOC production within the channel-floodplain system, which contained a small pond. In situ chlorophyll concentrations were also highly correlated with FDOM. FDOM showed a stronger storm response upstream than downstream, indicating terrestrial sources are mobilized by storms and subsequent dampening of the pulse by the floodplain. Nitrate concentrations consistently dropped from 0.6 to 0.7 mg/l upstream to less than 0.4 mg/l downstream, indicating likely nitrogen retention or removal over a relatively short distance (~500m). Use of in situ sensors is likely to greatly advance our understanding of biogeochemical processes in aquatic systems.

Geochemistry of the Mattole River in Northern California

USGS Publications Warehouse

Kennedy, Vance C.; Malcolm, Ronald L.

1977-01-01

The chemical composition of streams can vary greatly with changing discharge during storm runoff. These chemical changes are related to the pathways of various water parcels from the time they fall as rain until they enter the stream, and to the interactions between water and sediment during transport downstream. In order to understand better the chemical variations during storms, an extensive investigation was made of the Mattole River, a chemically clean coastal stream in Mendocino County, California. The Mattole drains a topographically mature basin of 620 sw km which has relief of about 1200 m, a long summer dry season, and mean annual rainfall of about 2300 mm. The stream flow is composed of seasonally varying proportions of four flow components, namely, surface runoff, quick-return flow (rainfall having brief and intimate contact with the soil before entering the surface drainage), delayed-return flow, and base runoff. Each component is identified by its characteristic chemistry and by the time delay between rainfall and entrance into the stream. Information is also presented on rain chemistry, adsorption reactions of suspended sediments in the fresh and brackish environments, and compositional variation of river sediments with particle size. (Woodard-USGS)

Nonpoint Source Road Salt Pollution from Urban Stormwater

NASA Astrophysics Data System (ADS)

DeGaetano, S.; Walter, M. T.

2014-12-01

In colder climates, such as the Northeast, road salts are commonly applied to deice roads in order to increase pedestrian and driver safety. This study was conducted to establish the mass if NaCl entering the local aquatic systems from Cornell's campus. Using trail cameras, two typical storm water pipes (draining into Cascadilla Creek) were monitored to determine the volume of runoff on an hourly bases. Grab samples were taken three times a week obtain storm water chloride concentration. In general, the average measured salt concentration was found to be 3.61 g/L, while high precipitation events Cl- concentration spiked to levels exceeding 12 g/L (≈ 20 g/L of salt). Combining runoff volumes and salt concentration values, a mass per drainage area was calculated for each monitored pipe. Outfall #1, located just upstream from the Wilson Synchrotron Module, expelled 262,300 kg of salt over a 42-day period of data collection while Outfall#2 discharged 4160 kg during the same period. These results were averaged and then applied to the total impervious area on Cornell's campus to approximate the total mass of sodium chloride leaving campus during the period of data collection.

Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy-- A U.S. Geological Survey Science Plan for Support of Restoration and Recovery

USGS Publications Warehouse

Buxton, Herbert T.; Andersen, Matthew E.; Focazio, Michael J.; Haines, John W.; Hainly, Robert A.; Hippe, Daniel J.; Sugarbaker, Larry J.

2013-01-01

n late October 2012, Hurricane Sandy came ashore during a spring high tide on the New Jersey coastline, delivering hurricane-force winds, storm tides exceeding 19 feet, driving rain, and plummeting temperatures. Hurricane Sandy resulted in 72 direct fatalities in the mid-Atlantic and northeastern United States, and widespread and substantial physical, environmental, ecological, social, and economic impacts estimated at near $50 billion. Before the landfall of Hurricane Sandy, the USGS provided forecasts of potential coastal change; collected oblique aerial photography of pre-storm coastal morphology; deployed storm-surge sensors, rapid-deployment streamgages, wave sensors, and barometric pressure sensors; conducted Light Detection And Ranging (lidar) aerial topographic surveys of coastal areas; and issued a landslide alert for landslide prone areas. During the storm, Tidal Telemetry Networks provided real-time water-level information along the coast. Long-term network and rapid-deployment real-time streamgages and water-quality monitors reported on river levels and changes in water quality. Immediately after the storm, the USGS serviced real-time instrumentation, retrieved data from over 140 storm-surge sensors, and collected other essential environmental data, including more than 830 high-water marks mapping the extent and elevation of the storm surge. Post-storm lidar surveys documented storm impacts to coastal barriers informing response and recovery and providing a new baseline to assess vulnerability of the reconfigured coast. The USGS Hazard Data Distribution System served storm related information from many agencies on the Internet on a daily basis. This science plan was developed immediately following Hurricane Sandy to coordinate continuing USGS activities with other agencies and to guide continued data collection and analysis to ensure support for recovery and restoration efforts. The data, information, and tools that are produced by implementing this plan will: (1) further characterize impacts and changes, (2) guide mitigation and restoration of impacted communities and ecosystems, (3) inform a redevelopment strategy aimed at developing resilient coastal communities and ecosystems, (4) improve preparedness and responsiveness to the next hurricane or similar coastal disaster, and (5) enable improved hazard assessment, response, and recovery for future storms along the hurricane prone shoreline of the United States. The activities outlined in this plan are organized in five themes based on impact types and information needs. These USGS science themes are: Theme 1: Coastal topography and bathymetry. Theme 2: Impacts to coastal beaches and barriers. Theme 3: Impacts of storm surge and estuarine and bay hydrology. Theme 4: Impacts on environmental quality and persisting contaminant exposures. Theme 5: Impacts to coastal ecosystems, habitats, and fish and wildlife. A major emphasis in the implementation of this plan will be on interacting with stakeholders to better understand their specific data and information needs, to define the best way to make information available, and to support applications of USGS science and expertise to decisionmaking.

A search for model parsimony in a real time flood forecasting system

NASA Astrophysics Data System (ADS)

Grossi, G.; Balistrocchi, M.

2009-04-01

As regards the hydrological simulation of flood events, a physically based distributed approach is the most appealing one, especially in those areas where the spatial variability of the soil hydraulic properties as well as of the meteorological forcing cannot be left apart, such as in mountainous regions. On the other hand, dealing with real time flood forecasting systems, less detailed models requiring a minor number of parameters may be more convenient, reducing both the computational costs and the calibration uncertainty. In fact in this case a precise quantification of the entire hydrograph pattern is not necessary, while the expected output of a real time flood forecasting system is just an estimate of the peak discharge, the time to peak and in some cases the flood volume. In this perspective a parsimonious model has to be found in order to increase the efficiency of the system. A suitable case study was identified in the northern Apennines: the Taro river is a right tributary to the Po river and drains about 2000 km2 of mountains, hills and floodplain, equally distributed . The hydrometeorological monitoring of this medium sized watershed is managed by ARPA Emilia Romagna through a dense network of uptodate gauges (about 30 rain gauges and 10 hydrometers). Detailed maps of the surface elevation, land use and soil texture characteristics are also available. Five flood events were recorded by the new monitoring network in the years 2003-2007: during these events the peak discharge was higher than 1000 m3/s, which is actually quite a high value when compared to the mean discharge rate of about 30 m3/s. The rainfall spatial patterns of such storms were analyzed in previous works by means of geostatistical tools and a typical semivariogram was defined, with the aim of establishing a typical storm structure leading to flood events in the Taro river. The available information was implemented into a distributed flood event model with a spatial resolution of 90m; then the hydrologic detail was reduced by progressively assuming a uniform rainfall field and constant soil properties. A semi-distributed model, obtained by subdividing the catchment into three sub-catchment, and a lumped model were also applied to simulate the selected flood events. Errors were quantified in terms of the peak discharge ratio, the flood volume and the time to peak by comparing the simulated hydrographs to the observed ones.

High resolution modelling of extreme precipitation events in urban areas

NASA Astrophysics Data System (ADS)

Siemerink, Martijn; Volp, Nicolette; Schuurmans, Wytze; Deckers, Dave

2015-04-01

The present day society needs to adjust to the effects of climate change. More extreme weather conditions are expected, which can lead to longer periods of drought, but also to more extreme precipitation events. Urban water systems are not designed for such extreme events. Most sewer systems are not able to drain the excessive storm water, causing urban flooding. This leads to high economic damage. In order to take appropriate measures against extreme urban storms, detailed knowledge about the behaviour of the urban water system above and below the streets is required. To investigate the behaviour of urban water systems during extreme precipitation events new assessment tools are necessary. These tools should provide a detailed and integral description of the flow in the full domain of overland runoff, sewer flow, surface water flow and groundwater flow. We developed a new assessment tool, called 3Di, which provides detailed insight in the urban water system. This tool is based on a new numerical methodology that can accurately deal with the interaction between overland runoff, sewer flow and surface water flow. A one-dimensional model for the sewer system and open channel flow is fully coupled to a two-dimensional depth-averaged model that simulates the overland flow. The tool uses a subgrid-based approach in order to take high resolution information of the sewer system and of the terrain into account [1, 2]. The combination of using the high resolution information and the subgrid based approach results in an accurate and efficient modelling tool. It is now possible to simulate entire urban water systems using extreme high resolution (0.5m x 0.5m) terrain data in combination with a detailed sewer and surface water network representation. The new tool has been tested in several Dutch cities, such as Rotterdam, Amsterdam and The Hague. We will present the results of an extreme precipitation event in the city of Schiedam (The Netherlands). This city deals with significant soil consolidation and the low-lying areas are prone to urban flooding. The simulation results are compared with measurements in the sewer network. References [1] Guus S. Stelling G.S., 2012. Quadtree flood simulations with subgrid digital elevation models. Water Management 165 (WM1):1329-1354. [2] Vincenzo Cassuli and Guus S. Stelling, 2013. A semi-implicit numerical model for urban drainage systems. International Journal for Numerical Methods in Fluids. Vol. 73:600-614. DOI: 10.1002/fld.3817

a Climatology of Synoptic Scale Atmospheric Structure Prior to Severe Convective Storms

NASA Astrophysics Data System (ADS)

Taylor, Gregory Eugene

1982-03-01

This investigation determines those unique properties of the thermodynamic and kinematic structure of the atmosphere in the region where tornado bearing thunderstorms develop as compared to surrounding locations. One hundred five upper air soundings from the operational rawinsonde network, hereafter called tornado proximity soundings, comprise the core of the data base. In each instance, a confirmed tornado occurred within 50 statute miles of and within 105 minutes after the release of the radiosonde. In earlier research of this nature, the thermodynamic and kinematic properties of the atmosphere in the region of tornado bearing thunderstorm development were interpolated or inferred from upper air soundings made at locations surrounding the severe storm location. These surrounding locations, however, were characterized by at most non-tornado bearing thunderstorm development. In this investigation, however, measurements of the atmospheric structure near in space and time to the subsequent tornado bearing thunderstorm development have been utilized. This fact should enhance the probability of detecting the presumably unique properties of the atmospheric structure prior to severe storm development as compared to previous investigations. Height, temperature, mixing ratio, and U and V wind component data from the tornado proximity sounding station and surrounding upper air stations were objectively analyzed to a regularly spaced three dimensional grid network centered on the tornado proximity sounding station. From the basic data, a large number of derived variables which had been previously linked to severe storms were computed. Each case was categorized into one of six different classifications based on the geographical location and date of the tornado proximity sounding. The results from the six categories indicate that the most pronounced unique properties of the pre-severe storm environment are within the lower levels of the atmosphere. In particular, the low level moisture content and the low level V-component tended to maximize near the region of subsequent severe storm development in most of the six categories. Also, a number of variables which are highly dependent upon low level moisture content and/or low level wind data such as horizontal moisture flux and stability indices delineated well the region of subsequent severe storm development.

Analyzing post-wildfire erosional processes and topographic change using hydrologic monitoring and Structure-from-Motion photogrammetry at the storm event scale

NASA Astrophysics Data System (ADS)

Leeper, R. J.; Barth, N. C.; Gray, A. B.

2017-12-01

Hydro-geomorphic response in recently burned watersheds is highly dependent on the timing and magnitude of subsequent rainstorms. Recent advancements in surveying and monitoring techniques using Unmanned Aerial Vehicles (UAV) and Structure-from-Motion (SfM) photogrammetry can support the rapid estimation of near cm-scale topographic response of headwater catchments (ha to km2). However, surface change due to shallow erosional processes such as sheetwash and rilling remain challenging to measure at this spatial extent and the storm event scale. To address this issue, we combined repeat UAV-SfM surveys with hydrologic monitoring techniques and field investigations to characterize post-wildfire erosional processes and topographic change on a storm-by-storm basis. The Las Lomas watershed ( 15 ha) burned in the 2016 San Gabriel Complex Fire along the front range of the San Gabriel Mountains, southern California. Surveys were conducted with a consumer grade UAV; twenty-six SfM control markers; two rain gages, and two pressure transducers were installed in the watershed. The initial SfM-derived point cloud generated from 422 photos contains 258 million points; the DEM has a resolution of 2.42 cm/pixel and a point density of 17.1 pts/cm2. Rills began forming on hillslopes and minor erosion occurred within the channel network during the first low intensity storms of the rainy season. Later more intense storms resulted in substantial geomorphic change. Hydrologic data indicate that during one of the intense storms total cumulative rainfall was 58.20 mm and peak 5-min intensity was 38.4 mm/hr. Poststorm field surveys revealed evidence of debris flows, flash flooding, erosion, and fluvial aggradation in the channel network, and rill growth and gully formation on hillslopes. Analyses of the SfM models indicate erosion dominated topographic change in steep channels and on hillslopes; aggradation dominated change in low gradient channels. A contrast of 5 cm exists between field measurements and change detected by differencing the SfM models. The quantitative and qualitative data sets obtained indicate that low-cost hydrologic monitoring techniques can be combined with SfM-derived high-resolution models to rapidly characterize post-wildfire hydrologic response and erosional processes on a storm event basis.

ASSESSING HEADWATER STREAMS: LINKING LANDSCAPES TO STREAM NETWORKS

EPA Science Inventory

Headwater streams represent a significant land-water boundary and drain 70-80% of the landscape. Headwater streams are vital components to drainage systems and are directly linked to our downstream rivers and lakes. However, alteration and loss of headwater streams have occurre...

Characterizing the Relationships Among Lightning and Storm Parameters: Lightning as a Proxy Variable

NASA Technical Reports Server (NTRS)

Goodman, S. J.; Raghavan, R.; William, E.; Weber, M.; Boldi, B.; Matlin, A.; Wolfson, M.; Hodanish, S.; Sharp. D.

1997-01-01

We have gained important insights from prior studies that have suggested relationships between lightning and storm growth, decay, convective rain flux, vertical distribution of storm mass and echo volume in the region, and storm energetics. A study was initiated in the Summer of 1996 to determine how total (in-cloud plus ground) lightning observations might provide added knowledge to the forecaster in the determination and identification of severe thunderstorms and weather hazards in real-time. The Melbourne Weather Office was selected as a primary site to conduct this study because Melbourne is the only site in the world with continuous and open access to total lightning (LDAR) data and a Doppler (WSR-88D) radar. A Lightning Imaging Sensor Data Applications Demonstration (LISDAD) system was integrated into the forecaster's workstation during the Summer 1996 to allow the forecaster to interact in real-time with the multi-sensor data being displayed. LISDAD currently ingests LDAR data, the cloud-to-ground National Lightning Detection Network (NLDN) data, and the Melbourne radar data in f real-time. The interactive features provide the duty forecaster the ability to perform quick diagnostics on storm cells of interest. Upon selection of a storm cell, a pop-up box appears displaying the time-history of various storm parameters (e.g., maximum radar reflectivity, height of maximum reflectivity, echo-top height, NLDN and LDAR lightning flash rates, storm-based vertically integrated liquid water content). This product is archived to aid on detailed post-analysis.

A novel approach to the dynamical complexity of the Earth's magnetosphere at geomagnetic storm time-scales based on recurrences

NASA Astrophysics Data System (ADS)

Donner, Reik; Balasis, Georgios; Stolbova, Veronika; Wiedermann, Marc; Georgiou, Marina; Kurths, Jürgen

2016-04-01

Magnetic storms are the most prominent global manifestations of out-of-equilibrium magnetospheric dynamics. Investigating the dynamical complexity exhibited by geomagnetic observables can provide valuable insights into relevant physical processes as well as temporal scales associated with this phenomenon. In this work, we introduce several innovative data analysis techniques enabling a quantitative analysis of the Dst index non-stationary behavior. Using recurrence quantification analysis (RQA) and recurrence network analysis (RNA), we obtain a variety of complexity measures serving as markers of quiet- and storm-time magnetospheric dynamics. We additionally apply these techniques to the main driver of Dst index variations, the V BSouth coupling function and interplanetary medium parameters Bz and Pdyn in order to discriminate internal processes from the magnetosphere's response directly induced by the external forcing by the solar wind. The derived recurrence-based measures allow us to improve the accuracy with which magnetospheric storms can be classified based on ground-based observations. The new methodology presented here could be of significant interest for the space weather research community working on time series analysis for magnetic storm forecasts.

How to Recognize and Distinguish Low-Latitude Ionospheric Storms Disturbances Produced by TIDs or PPEFs During Geomagnetic Storms

NASA Astrophysics Data System (ADS)

Fagundes, P. R.; Ribeiro, B. A.; Kavutarapu, V.; Fejer, B. G.; Pillat, V. G.

2016-12-01

The effects of geomagnetic storms on ionosphere are one of the important aspects of the space weather and identifying the possible sources of these perturbations is important. Among the possible sources of ionospheric perturbations, the Travelling Ionospheric Disturbance (TID) and Prompt Penetration Electric Field (PPEF) are the most important. In this study, we present and discuss the ionospheric response in the Brazilian sector due to geomagnetic storms occurred during January 2013 and March 2015. These space weather events were investigated using a network of 100 GPS-TEC stations. It has been noticed that the VTEC was disturbed during main phase in both storms. During the first event (January), a positive ionospheric storm peak in TEC is observed first beyond the EIA crest and sometime later at low-latitude and equatorial region. This delayed response at different latitudes could be a signature of TID propagation. In this specific event a TID propagating to northwest direction with a velocity of about 200 m/s. However, during the second event (March), 3 positive ionospheric storm peaks were observed in the VTEC from equator to low latitudes during the storm main phase, but these 3 peaks do not present wave propagation characteristics. Probably, an eastward electric field penetrated at equatorial and low-latitude regions uplifts the F-region where the recombination rates are lower leading to a positive ionospheric storm. To distinguish if the positive ionospheric storm was produced by TID or PPEF, it is important to observe the positive ionospheric storm changes along the meridional direction. In case of TIDs, a meridional propagation of the disturbance wave with a phase and speed will be observed. Therefore, the perturbation occurs first beyond the EIA crest and sometime later at the low latitudes and finally at the equatorial region. In case of PPEF the positive ionospheric storm takes place almost simultaneously from beyond the EIA crest to equatorial region.

Impacts of Extreme Space Weather Events on Power Grid Infrastructure: Physics-Based Modelling of Geomagnetically-Induced Currents (GICs) During Carrington-Class Geomagnetic Storms

NASA Astrophysics Data System (ADS)

Henderson, M. G.; Bent, R.; Chen, Y.; Delzanno, G. L.; Jeffery, C. A.; Jordanova, V. K.; Morley, S.; Rivera, M. K.; Toth, G.; Welling, D. T.; Woodroffe, J. R.; Engel, M.

2017-12-01

Large geomagnetic storms can have devastating effects on power grids. The largest geomagnetic storm ever recorded - called the Carrington Event - occurred in 1859 and produced Geomagnetically Induced Currents (GICs) strong enough to set fires in telegraph offices. It has been estimated that if such a storm occurred today, it would have devastating, long-lasting effects on the North American power transmission infrastructure. Acutely aware of this imminent threat, the North American Electric Reliability Corporation (NERC) was recently instructed to establish requirements for transmission system performance during geomagnetic disturbance (GMD) events and, although the benchmarks adopted were based on the best available data at the time, they suffer from a severely limited physical understanding of the behavior of GMDs and the resulting GICs for strong events. To rectify these deficiencies, we are developing a first-of-its-kind data-informed modelling capability that will provide transformational understanding of the underlying physical mechanisms responsible for the most harmful intense localized GMDs and their impacts on real power transmission networks. This work is being conducted in two separate modes of operation: (1) using historical, well-observed large storm intervals for which robust data-assimilation can be performed, and (2) extending the modelling into a predictive realm in order to assess impacts of poorly and/or never-before observed Carrington-class events. Results of this work are expected to include a potential replacement for the current NERC benchmarking methodology and the development of mitigation strategies in real power grid networks. We report on progress to date and show some preliminary results of modeling large (but not yet extreme) events.

Linking on-farm dairy management practices to storm-flow fecal coliform loading for California coastal watersheds.

PubMed

Lewis, D J; Atwill, E R; Lennox, M S; Hou, L; Karle, B; Tate, K W

2005-08-01

How and where to improve water quality within an agricultural watershed requires data at a spatial scale that corresponds with individual management decision units on an agricultural operation. This is particularly true in the context of water quality regulations, such as Total Maximum Daily Loads (TMDLs), that identify agriculture as one source of non-point source pollution through larger tributary watershed scale and above and below water quality investigations. We have conducted a systems approach study of 10 coastal dairies and ranches to document fecal coliform concentration and loading to surface waters at the management decision unit scale. Water quality samples were collected on a storm event basis from loading units that included: manure management systems; gutters; storm drains; pastures; and corrals and lots. In addition, in-stream samples were collected above and below the dairy facilities and from a control watershed, managed for light grazing and without a dairy facility or human residence and corresponding septic system. Samples were analyzed for fecal coliform concentration by membrane filtration. Instantaneous discharge was measured for each collected sample. Storm runoff was also calculated using the curve number method (SCS, 1985). Results for a representative dairy as well as the entire 10 dairy data set are presented. Fecal coliform concentrations demonstrate high variability both within and between loading units. Fecal coliform concentrations for pastures range from 206 to 2,288,888 cfu/100 ml and for lots from 1,933 to 166,105,000 cfu/100 ml. Mean concentrations for pastures and lots are 121,298 (SE = 62,222) and 3,155,584 (SE = 1,902,713) cfu/100 ml, respectively. Fecal coliform load from units of concentrated animals and manure are significantly more than units such as pastures while storm flow amounts were significantly less. Compared with results from earlier tributary scale studies in the watershed, this systems approach has generated water quality data that is beneficial for management decisions because of its scale and representation of current management activities. These results are facilitating on-farm changes through the cooperative efforts of dairy managers, regulatory agency staff, and sources of technical and financial assistance.

Drainage fracture networks in elastic solids with internal fluid generation

NASA Astrophysics Data System (ADS)

Kobchenko, Maya; Hafver, Andreas; Jettestuen, Espen; Galland, Olivier; Renard, François; Meakin, Paul; Jamtveit, Bjørn; Dysthe, Dag K.

2013-06-01

Experiments in which CO2 gas was generated by the yeast fermentation of sugar in an elastic layer of gelatine gel confined between two glass plates are described and analyzed theoretically. The CO2 gas pressure causes the gel layer to fracture. The gas produced is drained on short length scales by diffusion and on long length scales by flow in a fracture network, which has topological properties that are intermediate between river networks and hierarchical-fracture networks. A simple model for the experimental system with two parameters that characterize the disorder and the intermediate (river-fracture) topology of the network was developed and the results of the model were compared with the experimental results.

Extreme Event impacts on Seafloor Ecosystems

NASA Astrophysics Data System (ADS)

Canals, Miquel; Sanchez-Vidal, Anna; Calafat, Antoni; Pedrosa-Pàmies, Rut; Lastras, Galderic

2013-04-01

The Mediterranean region is among those presenting the highest concentration of cyclogenesis during the northern hemisphere winter, thus is frequently subjected to sudden events of extreme weather. The highest frequency of storm winds occur in its northwestern basin, and is associated to NE and NW storms. The occurrence of such extreme climatic events represents an opportunity of high scientific value to investigate how natural processes at their peaks of activity transfer matter and energy, as well as how impact ecosystems. Due to the approximately NE-SW orientation of the western Mediterranean coast, windforced motion coming from eastern storms generate the most intense waves and with very long fetch in the continental shelf and the coast, causing beach erosion, overwash and inundation of low-lying areas, and damage to infrastructures and coastal resources. On December 26, 2008 a huge storm afforded us the opportunity to understand the effect of storms on the deep sea ecosystems, as impacted violently an area of the Catalan coast covered by a dense network of monitoring devices including sediment traps and currentmeters. The storm, with measured wind gusts of more than 70 km h-1 and associated storm surge reaching 8 m, lead to the remobilisation of a shallow water large reservoir of marine organic carbon associated to fine particles and to its redistribution across the deep basin, and also ignited the motion of large amounts of coarse shelf sediment resulting in the abrasion and burial of benthic communities. In addition to eastern storms, increasing evidence has accumulated during the last few years showing the significance of Dense Shelf Water Cascading (DSWC), a type of marine current driven exclusively by seawater density contrast caused by strong and persistent NW winds, as a key driver of the deep Mediterranean Sea in many aspects. A network of mooring lines with sediment traps and currentmeters deployed in the Cap de Creus canyon in winter 2005-06 recorded a major DSWC event, the latest to date. Data show that DSWC modifies the properties of intermediate and deep waters, carries massive amounts of organic carbon to the basin thus fuelling the deep ecosystem, transports huge quantities of coarse and fine sedimentary particles that abrade canyon floors and rise the load of suspended particles, and also exports pollutants from the coastal area to deeper compartment. Our findings demonstrate that both types of climate-driven extreme events (coastal storms and DSWC) are highly efficient in transporting organic carbon from shallow to deep, thus contributing to its sequestration, and have the potential to tremendously impact the deep-sea ecosystems.

Flooding and streamflow in Utah during water year 2005

USGS Publications Warehouse

Wilkowske, C.D.; Kenney, T.A.; McKinney, T.S.

2006-01-01

The 2004 and 2005 water years illustrate why water managers in Utah generally describe the water supply as 'feast or famine.' In September 2004, Utah was finishing its sixth year of drought. Most reservoirs were substantially drained and the soil was parched. In contrast, in September 2005 Utah was finishing a water year that set new records for peak discharge and total annual streamflow.The 2004 water year ended on September 30, 2004. The 2005 water year brought with it a significant change in the weather, beginning with intense rainfall in the Virgin River basin of southwestern Utah. Only minor flooding resulted from this storm; however, it provided soil moisture that would contribute to severe flooding during January 2005.

Geophysical Tracking of a Subglacial Flood in Near Real-Time

NASA Astrophysics Data System (ADS)

Eibl, Eva P. S.; Jóhannesson, Tómas; Ofeigsson, Benedikt G.; Roberts, Matthew J.; Bean, Christopher J.; Vogfjörd, Kristin S.; Jones, Morgan T.; Pfeffer, Melissa A.; Bergsson, Baldur; Pálsson, Finnur

2017-04-01

Subglacial lakes and volcanoes in Iceland pose a risk to people, livestock and infrastructure when water drains in subglacial floods. Many of these floods occur every year and efforts are made to forecast them and evacuate in time. The two Skaftá cauldrons are located at the southwestern part of Vatnajökull glacier and usually drain once every two years. However, following drainage in 2010, the eastern cauldron did not drain before October 2015. While water accumulated over these five years, scientists - within the EU-funded project FutureVolc - improved the monitoring network around southwest Vatnajökull in order to record the flood in great detail. The network finally comprised two seismic arrays, a GPS instrument on top of the cauldron, two GPS instruments above the flood path, gas measurements at the glaciers' edge, hydrological measurements at river gauges and osmotic sampler data. We present how the GPS, gas and hydrological instruments allow us to detect the start of and subglacial propagation of the flood. The derived timing is consistent with the approximate time of rupturing of the ice close to the glacier edge and the source movement observed in the seismic signals. The subglacial flow of water is accompanied by seismic tremor, whose source location moves downslope with the flood front. This tremor is followed by about 24 hours of stronger tremor bursts from the direction of the empty cauldron.

A two-parameter design storm for Mediterranean convective rainfall

NASA Astrophysics Data System (ADS)

García-Bartual, Rafael; Andrés-Doménech, Ignacio

2017-05-01

The following research explores the feasibility of building effective design storms for extreme hydrological regimes, such as the one which characterizes the rainfall regime of the east and south-east of the Iberian Peninsula, without employing intensity-duration-frequency (IDF) curves as a starting point. Nowadays, after decades of functioning hydrological automatic networks, there is an abundance of high-resolution rainfall data with a reasonable statistic representation, which enable the direct research of temporal patterns and inner structures of rainfall events at a given geographic location, with the aim of establishing a statistical synthesis directly based on those observed patterns. The authors propose a temporal design storm defined in analytical terms, through a two-parameter gamma-type function. The two parameters are directly estimated from 73 independent storms identified from rainfall records of high temporal resolution in Valencia (Spain). All the relevant analytical properties derived from that function are developed in order to use this storm in real applications. In particular, in order to assign a probability to the design storm (return period), an auxiliary variable combining maximum intensity and total cumulated rainfall is introduced. As a result, for a given return period, a set of three storms with different duration, depth and peak intensity are defined. The consistency of the results is verified by means of comparison with the classic method of alternating blocks based on an IDF curve, for the above mentioned study case.

Statistical Patterns in Natural Lightning

NASA Astrophysics Data System (ADS)

Zoghzoghy, F. G.; Cohen, M.; Said, R.; Inan, U. S.

2011-12-01

Every day millions of lightning flashes occur around the globe but the understanding of this natural phenomenon is still lacking. Fundamentally, lightning is nature's way of destroying charge separation in clouds and restoring electric neutrality. Thus, statistical patterns of lightning activity indicate the scope of these electric discharges and offer a surrogate measure of timescales for charge buildup in thunderclouds. We present a statistical method to investigate spatio-temporal correlations among lightning flashes using National Lightning Detection Network (NLDN) stroke data. By monitoring the distribution of lightning activity, we can observe the charging and discharging processes in a given thunderstorm. In particular, within a given storm, the flashes do not occur as a memoryless random process. We introduce the No Flash Zone (NFZ) which results from the suppressed probability of two consecutive neighboring flashes. This effect lasts for tens of seconds and can extend up to 15 km around the location of the initial flash, decaying with time. This suppression effect may be a function of variables such as storm location, storm phase, and stroke peak current. We develop a clustering algorithm, Storm-Locator, which groups strokes into flashes, storm cells, and thunderstorms, and enables us to study lightning and the NFZ in different geographical regions, and for different storms. The recursive algorithm also helps monitor the interaction among spatially displaced storm cells, and can provide more insight into the spatial and temporal impacts of lightning discharges.

Observation and numerical simulation of a convective initiation during COHMEX

NASA Technical Reports Server (NTRS)

Song, J. Aaron; Kaplan, Michael L.

1991-01-01

Under a synoptically undisturbed condition, a dual-peak convective lifecycle was observed with the COoperative Huntsville Meteorological EXperiment (COHMEX) observational network over a 24-hour period. The lifecycle included a multicell storm, which lasted about 6 hours, produced a peak rainrate exceeding 100 mm/hr, and initiated a downstream mesoscale convective system. The 24-hour accumulated rainfall of this event was the largest during the entire COHMEX. The downstream mesoscale convective system, unfortunately, was difficult to investigate quantitatively due to the lack of mesoscale observations. The dataset collected near the time of the multicell storm evolution, including its initiation, was one of the best datasets of COHMEX. In this study, the initiation of this multicell storm is chosen as the target of the numerical simulations.

Real-time landslide warning during heavy rainfall

USGS Publications Warehouse

Keefer, D.K.; Wilson, R.C.; Mark, R.K.; Brabb, E.E.; Brown, W. M.; Ellen, S.D.; Harp, E.L.; Wieczorek, G.F.; Alger, C.S.; Zatkin, R.S.

1987-01-01

A real-time system for issuing warnings of landslides during major storms is being developed for the San Francisco Bay region, California. The system is based on empirical and theoretical relations between rainfall and landslide initiation, geologic determination of areas susceptible to landslides, real-time monitoring of a regional network of telemetering rain gages, and National Weather Service precipitation forecasts. This system was used to issue warnings during the storms of 12 to 21 February 1986, which produced 800 millimeters of rainfall in the region. Although analysis after the storms suggests that modifications and additional developments are needed, the system successfully predicted the times of major landslide events. It could be used as a prototype for systems in other landslide-prone regions.

Concentrations and Loads of Organic Compounds and Trace Elements in Tributaries to Newark and Raritan Bays, New Jersey

USGS Publications Warehouse

Wilson, Timothy P.; Bonin, Jennifer L.

2007-01-01

A study was undertaken to determine the concentrations and loads of sediment and chemicals delivered to Newark and Raritan Bays by five major tributaries: the Raritan, Passaic, Rahway, Elizabeth, and Hackensack Rivers. This study was initiated by the State of New Jersey as Study I-C of the New Jersey Toxics Reduction Workplan for the New York-New Jersey Harbor, working under the NY-NJ Harbor Estuary Program (HEP) Contaminant Assessment and Reduction Program (CARP). The CARP is a comprehensive effort to evaluate the levels and sources of toxic contaminants to the tributaries and estuarine areas of the NY-NJ Harbor, including Newark and Raritan Bays. The Raritan and Passaic Rivers are large rivers (mean daily discharges of 1,189 and 1,132 cubic feet per second (ft3/s), respectively), that drain large, mixed rural/urban basins. The Elizabeth and Rahway Rivers are small rivers (mean daily discharges of 25.9 and 49.1 ft3/s, respectively) that drain small, highly urbanized and industrialized basins. The Hackensack River drains a small, mixed rural/urban basin, and its flow is highly controlled by an upstream reservoir (mean daily discharge of 90.4 ft3/s). These rivers flow into urbanized estuaries and ultimately, to the Atlantic Ocean. Each of these tributaries were sampled during two to four storm events, and twice each during low-flow discharge conditions. Samples were collected using automated equipment installed at stations adjacent to U.S. Geological Survey streamflow-gaging stations near the heads-of-tide of these rivers. Large-volume (greater than 50 liters of water and a target of 1 gram of sediment), flow-weighted composite samples were collected for chemical analysis using filtration to collect suspended particulates and exchange resin (XAD-2) to sequester dissolved contaminants. Composite whole-water samples were collected for dissolved polycyclic aromatic hydrocarbons (PAH) and for trace element analysis. Additional discrete grab samples were collected throughout each event for trace-element analysis, and multiple samples were collected for suspended sediment (SS), particulate carbon (POC), and dissolved organic carbon (DOC) analysis. The suspended sediment and exchange resin were analyzed for 114 polychlorinated biphenyls (PCBs, by US EPA method 1668A, modified), seven 2,3,7,8-substituted chlorinated dibenzo-p-dioxins (CDD) and 10 dibenzo-p-difurans (CDF) (by US EPA method 1613), 24 PAHs (by low-resolution isotope dilution/mass-spectral methods), 27 organo-chlorine pesticides (OCPs) (by high resolution isotope dilution/mass-spectral methods), and the trace elements mercury (Hg), methyl-mercury (MeHg), lead (Pb), and cadmium (Cd). Isotope dilution methods using gas chromatography and high-and low-resolution mass spectral (GC/MS) detection were used to accurately identify and quantify organic compounds in the sediment and water phases. Trace elements were measured using inductively coupled plasma-mass spectrometry and cold-vapor atomic fluorescence spectrometry methods. The loads of sediment, carbon, and chemicals were calculated for each storm and low-flow event sampled. Because only a few storm events were sampled, yearly loads of sediment were calculated from rating curves developed using historical SS and POC data. The average annual loads of sediment and carbon were calculated for the period 1975-2000, along with the loads for the selected water years being modeled as part of the New York New Jersey Harbor Estuary Program CARP. Comparison of loads calculated using the rating curve method to loads measured during the sampled storm events indicated that the rating curve method likely underpredicts annual loads. Average annual loads of suspended sediment in the tributaries were estimated to be 395,000 kilograms per year (kg/yr) in the Hackensack River, 417,000 kg/yr in the Elizabeth River, 882,000 kg/yr in the Rahway River, 22,700,000 kg/yr in the Passaic River, and 93,100,000 kg/yr in the Raritan River. Averag

Response of nighttime equatorial and low latitude F-region to the geomagnetic storm of August 18, 2003, in the Brazilian sector

NASA Astrophysics Data System (ADS)

Sahai, Y.; Becker-Guedes, F.; Fagundes, P. R.; Lima, W. L. C.; Otsuka, Y.; Huang, C.-S.; Espinoza, E. S.; Pi, X.; de Abreu, A. J.; Bolzan, M. J. A.; Pillat, V. G.; Abalde, J. R.; Pimenta, A. A.; Bittencourt, J. A.

This paper presents an investigation of geomagnetic storm effects in the equatorial and low latitude F-region in the Brazilian sector during the intense geomagnetic storm on 18 August, 2003 (SSC 14:21 UT on 17/08; ΣKp = 52+; Ap = 108; ∣Dst∣ max = 168 at 1600 UT on 18/08). Simultaneous ionospheric sounding measurements from two stations, viz., Palmas (10.2°S, 48.2°W; dip latitude 5.7°S) and Sao Jose dos Campos (23.2°S, 45.9°W; dip latitude 17.6°S), Brazil, are presented for the nights of 16-17, 17-18 and 18-19 August, 2003 (quiet, disturbed and recovery phases). Both stations are equipped with the Canadian Advanced Digital Ionosonde (CADI). Quiet and disturbed conditions of the F-region ionosphere are compared using data collected from the two stations. The relationship between magnetospheric disturbance and low-latitude ionospheric dynamics, and generation of ionospheric irregularities are discussed. On the disturbed nights (17-18 and 18-19 August), the low latitude station S. J. Campos showed strong enhancements in the F-region critical frequency (foF2), whereas the near equatorial station Palmas showed strong uplifting of the F-layer about 1 h earlier. Normally during the June solstice months (May-August) in the Brazilian sector, large-scale ionospheric irregularities in form of plasma bubbles are rarely observed. On the night of 17-18 August, ionsospheric sounding observations at Palmas showed the presence of bottomside spread-F, whereas on the night of 18-19 August, the observations at Palmas and S. J. Campos showed the presence of plasma bubbles when the storm recovery phase had just started. The complementary GPS data available from several stations in the "Rede Brasileira de Monitoramento Continuo de GPS (Brazilian Network for Continuous GPS Monitoring)" are used to obtain the vertical total electron content (VTEC) and the rate of change of TEC per minute on UT days 18 and 19 August, 2003 and presented. Also, several global ionospheric TEC maps from the worldwide network of GPS receivers are presented, showing widespread latitudinal and longitudinal TEC changes during the different phases of the storm. All the observations (local ionospheric sounding and GPS network measurements, and global GPS measurements) presented in this investigation related to the geomagnetic storm on 18 August indicate that the equatorial and low latitude region in the Brazilian sector had much stronger effect during the recovery phase compared with the main phase. A comparison of the observed disturbance drifts with the Fejer-Scherliess storm-time model drifts indicate that the modeled drifts are not consistent with the present observations.

Multi-scale monitoring of a remarkable green roof: the Green Wave of Champs-sur-Marne

NASA Astrophysics Data System (ADS)

Stanic, Filip; Versini, Pierre-Antoine; Schertzer, Daniel; Delage, Pierre; Tchiguirinskaia, Ioulia; Cui, Yu-Jun; Baudoin, Genevieve

2017-04-01

The installation of green infrastructures on existing or new roofs has become very popular in recent years (more than 2 km2 of green roofs is implemented each year in France) for many reasons. Among all of the green roofs' advantages, those related to storm water management are often pushed forward, since it has been pointed out that urban runoff peak can be significantly reduced and delayed thanks to the green roofs' retention and detention capabilities. Microclimate can also be affected by decreasing the temperature in the surrounding green area. However, dynamic physical processes involved in green roofs are highly non linear and variable. In order to accurately assess their performances, detailed monitoring experiments are required, both in situ and in the lab, so as to better understand the thermo-hydric behaviour of green roofs and to capture the related spatio-temporal variability at different scales. Based on these considerations, the 1 ha area wavy-form green roof of a section of the Bienvenüe building, called the Green Wave, is currently being monitored in Champs-sur-Marne (France), in front of Ecole des Ponts ParisTech. Initiated in the "Blue Green Dream" European project, detailed measurements systems have been implemented for studying all components of the water balance. Among others, a wireless network of water content and temperature sensors has been especially installed for characterizing spatial and temporal variability of infiltration, retention and evapotranspiration processes. In parallel, some laboratory tests have been conducted to better characterize the hydro-mechanical properties of the substrate. Moreover, at the Green Wave scale, some discharge measurements are carried out in the storm-water pipes that are collecting drained water, to determine runoff flow. This talk will present the current monitoring campaigns and analyze the data collected in the Universal Multifractal framework. This work represents the initial stage for developing a model capable to simulate reliable hydrological responses of different kinds of green roofs. Such a tool could be used to quantify hydrological impacts and interfere with the stormwater policies at the lot scale.

Plasmonic welded single walled carbon nanotubes on monolayer graphene for sensing target protein

NASA Astrophysics Data System (ADS)

Kim, Jangheon; Kim, Gi Gyu; Kim, Soohyun; Jung, Wonsuk

2016-05-01

We developed plasmonic welded single walled carbon nanotubes (SWCNTs) on monolayer graphene as a biosensor to detect target antigen molecules, fc fusion protein without any treatment to generate binder groups for linker and antibody. This plasmonic welding induces atomic networks between SWCNTs as junctions containing carboxylic groups and improves the electrical sensitivity of a SWCNTs and the graphene membrane to detect target protein. We investigated generation of the atomic networks between SWCNTs by field-emission scanning electron microscopy and atomic force microscopy after plasmonic welding process. We compared the intensity ratios of D to G peaks from the Raman spectra and electrical sheet resistance of welded SWCNTs with the results of normal SWCNTs, which decreased from 0.115 to 0.086 and from 10.5 to 4.12, respectively. Additionally, we measured the drain current via source/drain voltage after binding of the antigen to the antibody molecules. This electrical sensitivity of the welded SWCNTs was 1.55 times larger than normal SWCNTs.

Spatial structures of stream and hillslope drainage networks following gully erosion after wildfire

USGS Publications Warehouse

Moody, J.A.; Kinner, D.A.

2006-01-01

The drainage networks of catchment areas burned by wildfire were analysed at several scales. The smallest scale (1-1000 m2) representative of hillslopes, and the small scale (1000 m2 to 1 km2), representative of small catchments, were characterized by the analysis of field measurements. The large scale (1-1000 km2), representative of perennial stream networks, was derived from a 30-m digital elevation model and analysed by computer analysis. Scaling laws used to describe large-scale drainage networks could be extrapolated to the small scale but could not describe the smallest scale of drainage structures observed in the hillslope region. The hillslope drainage network appears to have a second-order effect that reduces the number of order 1 and order 2 streams predicted by the large-scale channel structure. This network comprises two spatial patterns of rills with width-to-depth ratios typically less than 10. One pattern is parallel rills draining nearly planar hillslope surfaces, and the other pattern is three to six converging rills draining the critical source area uphill from an order 1 channel head. The magnitude of this critical area depends on infiltration, hillslope roughness and critical shear stress for erosion of sediment, all of which can be substantially altered by wildfire. Order 1 and 2 streams were found to constitute the interface region, which is altered by a disturbance, like wildfire, from subtle unchannelized drainages in unburned catchments to incised drainages. These drainages are characterized by gullies also with width-to-depth ratios typically less than 10 in burned catchments. The regions (hillslope, interface and chanel) had different drainage network structures to collect and transfer water and sediment. Copyright ?? 2005 John Wiley & Sons, Ltd.

Meteorological effects on the levels of fecal indicator bacteria in an urban stream: a modeling approach.

PubMed

Cho, Kyung Hwa; Cha, Sung Min; Kang, Joo-Hyon; Lee, Seung Won; Park, Yongeun; Kim, Jung-Woo; Kim, Joon Ha

2010-04-01

Gwangju Creek (GJC) in Korea, which drains a highly urbanized watershed, has suffered from substantial fecal contamination, thereby limiting the beneficial use of the water in addition to threatening public health. In this study, to quantitatively estimate the sinks and sources of fecal indicator bacteria (FIB) in GJC under varying meteorological conditions, two FIB (i.e., Escherichia coli and enterococci bacteria) were monitored hourly for 24h periods during both wet and dry weather conditions at four sites along GJC, and the collected data was subsequently used to develop a spatiotemporal FIB prediction model. The monitoring data revealed that storm washoff and irradiational die-off by sunlight are the two key processes controlling FIB populations in wet and dry weather, respectively. FIB populations significantly increased during precipitation, with greater concentrations occurring at higher rainfall intensity. During dry weather, FIB populations decreased in the presence of sunlight in daytime but quickly recovered at nighttime due to continuous point-source inputs. In this way, the contributions of the key processes (i.e., irradiational die-off by sunlight, settling, storm washoff, and resuspension) to the FIB levels in GJC under different meteorological conditions were quantitatively estimated using the developed model. The modeling results showed that the die-off by sunlight is the major sink of FIB during the daytime in dry weather with a minor contribution from the settling process. During wet weather, storm washoff and resuspension are equally important processes that are responsible for the substantial increase of FIB populations. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Analysis of Spatial Autocorrelation for Optimal Observation Network in Korea

NASA Astrophysics Data System (ADS)

Park, S.; Lee, S.; Lee, E.; Park, S. K.

2016-12-01

Many studies for improving prediction of high-impact weather have been implemented, such as THORPEX (The Observing System Research and Predictability Experiment), FASTEX (Fronts and Atlantic Storm-Track Experiment), NORPEX (North Pacific Experiment), WSR/NOAA (Winter Storm Reconnaissance), and DOTSTAR (Dropwindsonde Observations for Typhoon Surveillance near the TAiwan Region). One of most important objectives in these studies is to find effects of observation on forecast, and to establish optimal observation network. However, there are lack of such studies on Korea, although Korean peninsula exhibits a highly complex terrain so it is difficult to predict its weather phenomena. Through building the future optimal observation network, it is necessary to increase utilization of numerical weather prediction and improve monitoring·tracking·prediction skills of high-impact weather in Korea. Therefore, we will perform preliminary study to understand the spatial scale for an expansion of observation system through Spatial Autocorrelation (SAC) analysis. In additions, we will develop a testbed system to design an optimal observation network. Analysis is conducted with Automatic Weather System (AWS) rainfall data, global upper air grid observation (i.e., temperature, pressure, humidity), Himawari satellite data (i.e., water vapor) during 2013-2015 of Korea. This study will provide a guideline to construct observation network for not only improving weather prediction skill but also cost-effectiveness.

Observations of lightning in convective supercells within tropical storms and hurricanes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyons, W.A.; Keen, C.S.

1994-08-01

Cloud-to-ground (CG) lightning observations from land-based lightning detection networks now allow monitoring this component of the electrical structure of tropical storms and hurricanes within a few hundred kilometers of the United States coastline. Several case studies confirm the long-held opinion that lightning is rather common within the outer rainbands. The general absence of CG lightning within the interior of mature tropical cyclones is also apparent. On the other hand, bursts of CG lightning near the circulation center of developing storms appear to precede periods of further deepening. The CG events are associated with convective supercells, whose anvil canopies can oftenmore » obscure much of the underlying storm. Near-eyewall CG bursts preceding periods of intensification were noted in Hurricanes Diana (1984) and Florence (1988). A detailed case study of the 1987 unnamed tropical storm that struck the Texas-Louisiana coastline reveals that lightning was associated with two large supercells. These supercells appeared to be the trigger for the development of a closed circulation that formed several hours after the apparent low pressure center made landfall. Further studies of lightning may provide additional insight into the role of convective supercells in tropical storm intensification. It may also provide a useful diagnostic of impending deepening.« less

Thermodynamic Profiles of the Destructive June 2012 Derecho

NASA Astrophysics Data System (ADS)

Liu, C.; Novakovskaia, E.; Bosse, J.; Ware, R.; Stillman, D.; Sloop, C.; Blanchette, L.; Demoz, B.; Nelson, M.; Cooper, L.; Czarnetzki, A.; Reehorst, A.

2012-12-01

The June 2012 mid-Atlantic and Midwest Derecho was one of the most destructive and deadly fast-moving severe thunderstorm events in North American history. The derecho produced wind gusts approaching 100 miles per hour as it traveled more than 600 miles across large sections of the Midwestern United States, the central Appalachians and the Mid-Atlantic States on the afternoon and evening of June 29, 2012 and into the early morning of June 30, 2012. It produced hurricane-like impacts with little warning, resulting in more than 20 deaths, widespread damage and millions of power outages across the entire affected region. We present continuous temperature and moisture profiles observed by microwave radiometers, and derived forecast indices, along the storm path at locations in Iowa, Ohio and Maryland, providing unique perspective on the evolution of this historic storm. For example, an extreme CAPE value of 5,000 J/kg was derived from radiometer observations at Germantown, Maryland ten hours before storm passage, and 80 knot Wind Index (WINDEX) was derived seven hours before passage. The Germantown radiometer is operated as part of the Earth Networks Boundary Layer Network (BLN) for continuous thermodynamic monitoring of the planetary boundary layer up to 30,000 feet. The BLN uses Radiometrics microwave profilers providing continuous temperature and humidity soundings with radiosonde-equivalent observation accuracy, and unique liquid soundings. This case study illustrates the promise for severe storm forecast improvement based on continuous monitoring of temperature and moisture in the boundary layer and above.

Urban Stormwater Management Model and Tools for Designing Stormwater Management of Green Infrastructure Practices

NASA Astrophysics Data System (ADS)

Haris, H.; Chow, M. F.; Usman, F.; Sidek, L. M.; Roseli, Z. A.; Norlida, M. D.

2016-03-01

Urbanization is growing rapidly in Malaysia. Rapid urbanization has known to have several negative impacts towards hydrological cycle due to decreasing of pervious area and deterioration of water quality in stormwater runoff. One of the negative impacts of urbanization is the congestion of the stormwater drainage system and this situation leading to flash flood problem and water quality degradation. There are many urban stormwater management softwares available in the market such as Storm Water Drainage System design and analysis program (DRAINS), Urban Drainage and Sewer Model (MOUSE), InfoWorks River Simulation (InfoWork RS), Hydrological Simulation Program-Fortran (HSPF), Distributed Routing Rainfall-Runoff Model (DR3M), Storm Water Management Model (SWMM), XP Storm Water Management Model (XPSWMM), MIKE-SWMM, Quality-Quantity Simulators (QQS), Storage, Treatment, Overflow, Runoff Model (STORM), and Hydrologic Engineering Centre-Hydrologic Modelling System (HEC-HMS). In this paper, we are going to discuss briefly about several softwares and their functionality, accessibility, characteristics and components in the quantity analysis of the hydrological design software and compare it with MSMA Design Aid and Database. Green Infrastructure (GI) is one of the main topics that has widely been discussed all over the world. Every development in the urban area is related to GI. GI can be defined as green area build in the develop area such as forest, park, wetland or floodway. The role of GI is to improve life standard such as water filtration or flood control. Among the twenty models that have been compared to MSMA SME, ten models were selected to conduct a comprehensive review for this study. These are known to be widely accepted by water resource researchers. These ten tools are further classified into three major categories as models that address the stormwater management ability of GI in terms of quantity and quality, models that have the capability of conducting the economic analysis of GI and models that can address both stormwater management and economic aspects together.

Mid-latitude response to geomagnetic storms observed in 630nm airglow over continental United States

NASA Astrophysics Data System (ADS)

Bhatt, A.; Kendall, E. A.

2016-12-01

We present analysis of mid-latitude response observed to geomagnetic storms using the MANGO network consisting of all-sky cameras imaging 630nm emission over the continental United States. The response largely falls in two categories: Stable Auroral Red (SAR) arc and Large-scale traveling ionospheric disturbances (LSTIDs). However, outside of these phenomena, less often observed response include anomalous airglow brightening, bright swirls, and frozen in traveling structures. We will present an analysis of various events observed over 3 years of MANGO network operation, which started with two imagers in the western US with addition of new imagers in the last year. We will also present unusual north and northeastward propagating waves often observed in conjunction with diffuse aurora. Wherever possible, we will compare with observations from Boston University imagers located in Massachusetts and Texas.

Probabilistic prediction of barrier-island response to hurricanes

USGS Publications Warehouse

Plant, Nathaniel G.; Stockdon, Hilary F.

2012-01-01

Prediction of barrier-island response to hurricane attack is important for assessing the vulnerability of communities, infrastructure, habitat, and recreational assets to the impacts of storm surge, waves, and erosion. We have demonstrated that a conceptual model intended to make qualitative predictions of the type of beach response to storms (e.g., beach erosion, dune erosion, dune overwash, inundation) can be reformulated in a Bayesian network to make quantitative predictions of the morphologic response. In an application of this approach at Santa Rosa Island, FL, predicted dune-crest elevation changes in response to Hurricane Ivan explained about 20% to 30% of the observed variance. An extended Bayesian network based on the original conceptual model, which included dune elevations, storm surge, and swash, but with the addition of beach and dune widths as input variables, showed improved skill compared to the original model, explaining 70% of dune elevation change variance and about 60% of dune and shoreline position change variance. This probabilistic approach accurately represented prediction uncertainty (measured with the log likelihood ratio), and it outperformed the baseline prediction (i.e., the prior distribution based on the observations). Finally, sensitivity studies demonstrated that degrading the resolution of the Bayesian network or removing data from the calibration process reduced the skill of the predictions by 30% to 40%. The reduction in skill did not change conclusions regarding the relative importance of the input variables, and the extended model's skill always outperformed the original model.

Differential behaviour of Escherichia coli and Campylobacter spp. in a stream draining dairy pasture.

PubMed

Stott, Rebecca; Davies-Colley, Robert; Nagels, John; Donnison, Andrea; Ross, Colleen; Muirhead, Richard

2011-03-01

The faecal indicator bacterium Escherichia coli and thermotolerant Campylobacter spp., which are potentially pathogenic, were investigated in the Toenepi Stream draining a pastoral catchment dominated by dairying. Bacteria concentrations were monitored routinely at fortnightly intervals over 12 months and intensively during storm events to compare the transport dynamics of bacterial indicator and pathogen under varying hydro-meteorological conditions. Routine monitoring indicated median concentrations of 345 E. coli MPN 100 ml(-1) and relatively low concentrations of 2.3 Campylobacter MPN 100 ml(-1). The bacterial flux was three orders of magnitude greater under elevated stream flow compared with base-flow. E. coli peak concentrations occurred very close to the turbidity peak and consistently ahead of the Campylobacter spp. peak (which was close to the hydrograph peak). We postulate that, under flood conditions, the E. coli peak reflects the entrainment and mobilisation of in-stream stores on the flood wave front. In contrast, Campylobacter spp. are derived from wash-in from land stores upstream and have travelled at the mean water velocity which is slower than the speed of the flood wave. Our findings of different dynamics for E. coli and Campylobacter spp. suggest that mitigation to reduce faecal microbial impacts from farms will need to take account of these differences.

Promoting nitrate removal in rain gardens | Science Inventory ...

EPA Pesticide Factsheets

Rain gardens are vegetated surface depressions, often located at low points in landscapes, designed to receive stormwater runoff from roads, roofs, and parking lots. The gardens’ sandy soils allow stormwater to drain quickly to the native soils below and eventually to groundwater. The rain garden vegetation and soils remove pollutants and nutrients from stormwater runoff through biological and physical processes such as plant uptake and sorption to soil particles. In comparison with stormwater release to receiving waters through conventional storm drain systems, infiltrating stormwater through rain gardens reduces peak flows and loadings of both pollutants and nutrients. This reduction improves the physical and biological integrity of receiving streams by reducing stream bank erosion and negative effects on stream communities. While local governments and individual homeowners are building these systems, relatively few scientific studies have documented the ability of rain gardens to remove pollutants and nutrients. This U.S. EPA long-term research project investigates: 1) the performance of rain gardens in removing pollutants, and 2) whether currently-accepted design standards can be adjusted to improve nitrate removal capabilities. Typical rain garden designs provide large removals of pollutants of concern, including heavy metals, phosphorus, total nitrogen, and ammonium. The gardens have been less successful in removing nitrate, an importan

Investigation of malaria prevalence at National Thermal Power Corporation, Shaktinagar, Sonbhadra District (Uttar Pradesh), India.

PubMed

Dua, V K; Nanda, N; Gupta, N C; Kar, P K; Subbarao, S K; Sharma, V P

2000-12-01

Malaria in industrial complexes is promoted by extensive mosquitogenic potential generated by excavations and importation of parasite through migratory labor. The National Thermal Power Corporation (NTPC), Shaktinagar, Sonbhadra district was surveyed for malariogenic conditions from 1994 to 1996. The major mosquito breeding sites were drains, storm-water drains, lakes, outside tanks, overhead tanks, sluice-valve chambers, ornamental tanks, wells, pit wells and water reservoirs, etc. Anopheles culicifacies was the major vector of malaria in this area. Sibling species identification of An. culicifacies revealed that species C predominated during the transmission season and responsible to transmit malaria. Insecticide susceptibility tests against An. culicifacies sl showed that An.culicifacies population was 100% susceptible to malathion, fenitrothorn and deltamethrin while it was found 44% resistant to DDT. The malaria cases recorded in 1994, 1995 and 1996 were 847, 590 and 409 respectively. In vitro study on P. falciparum cases showed that 41, 70, 50% of the isolates tested were resistant to chloroquine in 1994, 1995 and 1996 respectively while an in vivo follow-up study showed 20-30% P. falciparum cases resistant to chloroquine. An integrated approach involving alternate vector control measures along with judicious use of insecticides has been suggested to bring down malaria in industrial complexes.

A Coordinated USGS Science Response to Hurricane Sandy

NASA Astrophysics Data System (ADS)

Jones, S.; Buxton, H. T.; Andersen, M.; Dean, T.; Focazio, M. J.; Haines, J.; Hainly, R. A.

2013-12-01

In late October 2012, Hurricane Sandy came ashore during a spring high tide on the New Jersey coastline, delivering hurricane-force winds, storm tides exceeding 19 feet, driving rain, and plummeting temperatures. Hurricane Sandy resulted in 72 direct fatalities in the mid-Atlantic and northeastern United States, and widespread and substantial physical, environmental, ecological, social, and economic impacts estimated at near $50 billion. Before the landfall of Hurricane Sandy, the USGS provided forecasts of potential coastal change; collected oblique aerial photography of pre-storm coastal morphology; deployed storm-surge sensors, rapid-deployment streamgages, wave sensors, and barometric pressure sensors; conducted Light Detection and Ranging (lidar) aerial topographic surveys of coastal areas; and issued a landslide alert for landslide prone areas. During the storm, Tidal Telemetry Networks provided real-time water-level information along the coast. Long-term networks and rapid-deployment real-time streamgages and water-quality monitors tracked river levels and changes in water quality. Immediately after the storm, the USGS serviced real-time instrumentation, retrieved data from over 140 storm-surge sensors, and collected other essential environmental data, including more than 830 high-water marks mapping the extent and elevation of the storm surge. Post-storm lidar surveys documented storm impacts to coastal barriers informing response and recovery and providing a new baseline to assess vulnerability of the reconfigured coast. The USGS Hazard Data Distribution System served storm-related information from many agencies on the Internet on a daily basis. Immediately following Hurricane Sandy the USGS developed a science plan, 'Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy-A U.S. Geological Survey Science Plan for Support of Restoration and Recovery'. The plan will ensure continuing coordination of internal USGS activities as well as enhancing our work with other agencies. The data, information, and tools that are being produced by implementing this plan will: (1) further characterize impacts and changes, (2) guide mitigation and restoration of impacted communities and ecosystems, (3) inform a redevelopment strategy aimed at developing resilient coastal communities and ecosystems, (4) improve preparedness and responsiveness to the next hurricane or similar coastal disaster, and (5) enable improved hazard assessment, response, and recovery for future storms along the hurricane prone shoreline of the United States. The activities outlined in the plan are organized in five themes based on impact types and information needs. These USGS science themes are: Theme 1: Coastal topography and bathymetry. Theme 2: Impacts to coastal beaches and barriers. Theme 3: Impacts of storm surge and estuarine and bay hydrology. Theme 4: Impacts on environmental quality and persisting contaminant exposures. Theme 5: Impacts to coastal ecosystems, habitats, and fish and wildlife. The major emphases in the implementation of this plan are interacting with stakeholders to better understand their specific data and information needs, engaging with other Federal agencies and non-governmental agencies to encourage collaboration and avoid duplication, defining the best way to make information available, and providing applications of USGS science and expertise to support decision-making.

Nutrients, Dissolved Organic Carbon, Color, and Disinfection Byproducts in Base Flow and Stormflow in Streams of the Croton Watershed, Westchester and Putnam Counties, New York, 2000-02

USGS Publications Warehouse

Heisig, Paul M.

2009-01-01

The Croton Watershed is unique among New York City's water-supply watersheds because it has the highest percentages of suburban development (52 percent) and wetland area (6 percent). As the City moves toward filtration of this water supply, there is a need to document water-quality contributions from both human and natural sources within the watershed that can inform watershed-management decisions. Streamwater samples from 24 small (0.1 to 1.5 mi2) subbasins and three wastewater-treatment plants (2000-02) were used to document the seasonal concentrations, values, and formation potentials of selected nutrients, dissolved organic carbon (DOC), color, and disinfection byproducts (DBPs) during stormflow and base-flow conditions. The subbasins were categorized by three types of drainage efficiency and a range of land uses and housing densities. Analyte concentrations in subbasin streams differed in response to the subbasin charateristics. Nutrient concentrations were lowest in undeveloped, forested subbasins that were well drained and increased with all types of development, which included residential, urban commercial/industrial, golf-course, and horse-farm land uses. These concentrations were further modified by subbasin drainage efficiency. DOC, in contrast, was highly dependent on drainage efficiency. Color intensity and DBP formation potentials were, in turn, associated with DOC and thus showed a similar response to drainage efficiency. Every constituent exhibited seasonal changes in concentration. Nutrients. Total (unfiltered) phosphorus (TP), soluble reactive phosphorus (SRP), and nitrate were associated primarily with residential development, urban, golf-course, and horse-farm land uses. Base-flow and stormflow concentrations of the TP, SRP, and nitrate generally increased with increasing housing density. TP and SRP concentrations were nearly an order of magnitude higher in stormflow than in base flow, whereas nitrate concentrations showed little difference between these flow conditions. Organic nitrogen concentrations (calculated as the difference between concentrations of total dissolved N and of all other N species) was the dominant form of nitrogen in undeveloped and moderately to poorly drained subbasins. High TP concentrations in stormflows (800-1,750 ug/L) were associated with well drained and moderately drained residential subbasins with high- and medium-density housing and with the moderately drained golf-course subbasin. Areas with medium to high housing densities favor TP transport because they provide extensive impervious surfaces, storm sewers, and local relief, which together can rapidly route stormwater to streams. SRP concentrations were highest in the same types of subbasins as TP, but also in sewered residential and horse-farm subbasins. The ratio of SRP to TP was typically a smaller in stormflow than in base flow. Base-flow TP and SRP concentrations were highest during the warm-weather months (May to October). The highest nitrate concentrations (3.0-4.5 mg/L) were associated with the urban subbasin and the three well drained, high-density residential subbasins. The two moderately drained lake subbasins and the two poorly drained (colored-water wetland) subbasins had consistently low nitrate concentrations despite low and medium housing densities. Nitrate concentrations were generally highest during the winter months and lowest during the autumn leaf-fall period. Organic N concentrations were highest during the leaf-fall period. Dissolved Organic Carbon. DOC concentration was consistently highest in the two poorly drained (colored-water-wetland) subbasins and lowest in the well drained subbasins. Base-flow DOC concentration increased with decreasing drainage efficiency, except in the well drained sewered subbasin with high-density housing, where slightly elevated DOC concentrations throughout the year may indicate leakage from a nearby sewer main. Seasonal changes in stormflow DOC concentrat

More frequent intense and long-lived storms dominate the springtime trend in central US rainfall

PubMed Central

Feng, Zhe; Leung, L. Ruby; Hagos, Samson; Houze, Robert A.; Burleyson, Casey D.; Balaguru, Karthik

2016-01-01

The changes in extreme rainfall associated with a warming climate have drawn significant attention in recent years. Mounting evidence shows that sub-daily convective rainfall extremes are increasing faster than the rate of change in the atmospheric precipitable water capacity with a warming climate. However, the response of extreme precipitation depends on the type of storm supported by the meteorological environment. Here using long-term satellite, surface radar and rain-gauge network data and atmospheric reanalyses, we show that the observed increases in springtime total and extreme rainfall in the central United States are dominated by mesoscale convective systems (MCSs), the largest type of convective storm, with increased frequency and intensity of long-lasting MCSs. A strengthening of the southerly low-level jet and its associated moisture transport in the Central/Northern Great Plains, in the overall climatology and particularly on days with long-lasting MCSs, accounts for the changes in the precipitation produced by these storms. PMID:27834368

A kinetic energy study of the meso beta-scale storm environment during AVE-SESAME 5 (20-21 May 1979)

NASA Technical Reports Server (NTRS)

Printy, M. F.; Fuelberg, H. E.

1984-01-01

Kinetic energy of the near storm environment was analyzed by meso beta scale data. It was found that horizontal winds in the 400 to 150 mb layer strengthen rapidly north of the developing convection. Peak values then decrease such that the maximum disappears 6 h later. Southeast of the storms, wind speeds above 300 mb decrease nearly 50% during the 3 h period of most intense thunderstorm activity. When the convection dissipates, wind patterns return to prestorm conditions. The mesoscale storm environment of AVE-SESAME 5 is characterized by large values of cross contour generation of kinetic energy, transfers of energy to nonresolvable scales of motion, and horizontal flux divergence. These processes are maximized within the upper troposphere and are greatest during times of strongest convection. It is shown that patterns agree with observed weather features. The southeast area of the network is examined to determine causes for vertical wind variations.

More frequent intense and long-lived storms dominate the springtime trend in central US rainfall

DOE PAGES

Feng, Zhe; Leung, L. Ruby; Hagos, Samson M.; ...

2016-11-11

Here, the changes in extreme rainfall associated with a warming climate have drawn significant attention in recent years. Mounting evidence shows that sub-daily convective rainfall extremes are increasing faster than the rate of change in the atmospheric precipitable water capacity with a warming climate. However, the response of extreme precipitation depends on the type of storm supported by the meteorological environment. Here using long-term satellite, surface radar and rain-gauge network data and atmospheric reanalyses, we show that the observed increases in springtime total and extreme rainfall in 36 the central U.S. are dominated by mesoscale convective systems (MCSs), the largestmore » type of convective storm, with increased frequency and intensity of long-lasting MCSs. A strengthening of the southerly low-level jet and its associated moisture transport in the Central/Northern Great Plains, in the overall climatology and particularly on days with long-lasting MCSs, accounts for the changes in the precipitation produced by these storms.« less

More frequent intense and long-lived storms dominate the springtime trend in central US rainfall

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Zhe; Leung, L. Ruby; Hagos, Samson M.

Here, the changes in extreme rainfall associated with a warming climate have drawn significant attention in recent years. Mounting evidence shows that sub-daily convective rainfall extremes are increasing faster than the rate of change in the atmospheric precipitable water capacity with a warming climate. However, the response of extreme precipitation depends on the type of storm supported by the meteorological environment. Here using long-term satellite, surface radar and rain-gauge network data and atmospheric reanalyses, we show that the observed increases in springtime total and extreme rainfall in 36 the central U.S. are dominated by mesoscale convective systems (MCSs), the largestmore » type of convective storm, with increased frequency and intensity of long-lasting MCSs. A strengthening of the southerly low-level jet and its associated moisture transport in the Central/Northern Great Plains, in the overall climatology and particularly on days with long-lasting MCSs, accounts for the changes in the precipitation produced by these storms.« less

Lymphatics in Neurological Disorders: A neuro-lympho-vascular Component of Multiple Sclerosis and Alzheimer’s Disease

PubMed Central

Louveau, Antoine; Mesquita, Sandro Da; Kipnis, Jonathan

2016-01-01

Summary Lymphatic vasculature drains interstitial fluids, which contain the tissue’s waste products and ensures immune surveillance of the tissues, allowing immune-cell recirculation. Until recently the central nervous system (CNS) was considered to be devoid of a conventional lymphatic vasculature. The recent discovery in the meninges of a lymphatic network that drains the CNS calls into question classic models for the drainage of macromolecules and immune cells from the CNS. In the context of neurological disorders, the presence of a lymphatic system draining the CNS potentially offers a new player and a new avenue for therapy. In this review, we will attempt to integrate the known primary functions of the tissue lymphatic vasculature that exists in peripheral organs with the proposed function of meningeal lymphatic vessels in neurological disorders, specifically multiple sclerosis and Alzheimer’s disease. We propose that these (and potentially other) neurological afflictions can be viewed as diseases with neuro-lympho-vascular component and should be therapeutically targeted as such. PMID:27608759

Dynamic river networks as the context for evaluating riparian influence on river basin solute export

EPA Science Inventory

Many studies have examined the influence of riparian areas on nitrogen as water drains from hillslopes and through riparian zones at the stream reach scale. Most of these studies have been conducted along relatively small streams. However, water quality concerns typically deal wi...

Assessing impacts of land-applied manure from concentrated animal feeding operations on fish populations and communities

EPA Science Inventory

Concentrated animal feeding operation (CAFO) waste is a cost effective fertilizer. In the Midwest, networks of subsurface tile-drains expedite transport of animal hormones and nutrients from land-applied CAFO waste to adjacent waterways. The objective of this study was to evaluat...

Dynamic reorganization of river basins.

PubMed

Willett, Sean D; McCoy, Scott W; Perron, J Taylor; Goren, Liran; Chen, Chia-Yu

2014-03-07

River networks evolve as migrating drainage divides reshape river basins and change network topology by capture of river channels. We demonstrate that a characteristic metric of river network geometry gauges the horizontal motion of drainage divides. Assessing this metric throughout a landscape maps the dynamic states of entire river networks, revealing diverse conditions: Drainage divides in the Loess Plateau of China appear stationary; the young topography of Taiwan has migrating divides driving adjustment of major basins; and rivers draining the ancient landscape of the southeastern United States are reorganizing in response to escarpment retreat and coastal advance. The ability to measure the dynamic reorganization of river basins presents opportunities to examine landscape-scale interactions among tectonics, erosion, and ecology.

Meso-beta scale perturbations of the wind field by thunderstorm cells

NASA Technical Reports Server (NTRS)

Ulanski, S. L.; Heymsfield, G. M.

1986-01-01

Data from the high density storm-scale rawinsonde network of the Severe Environmental Storms and Mesoscale Experiment revealed temporal and spatial changes in the divergence fields of the troposphere in response to severe storm evolution on May 2, 1979; these changes were detectable on the meso-beta scale. This unique set of data was subsequently used to study the evolution of the wind, divergence and vertical motion fields in the presence of intense convection. Mid- and upper-tropospheric divergence was superimposed over low-level convergence. The divergence, which has a maximum value of .0004/s, occurred 75 to 100 km upwind as well as over the tornadic cells. To the south of the storm cells, the kinematic pattern was in reverse, upper level convergence was superimposed over low-level divergence. A vertical motion doublet was found to ascend over the squall line and descend about 70 km south of the squall line. It is suggested that the following effects are accountable for the nature of the kinematic fields: (1) blocking of tropospheric environmental flow by the storm cells, (2) anvil outflows, particularly from the tornadic cells, and (3) divergence from the exit region of the jet stream.

GPS Detection of Biot's Slow Wave in the Earth's Crust Triggered by Hurricane Sandy

NASA Astrophysics Data System (ADS)

Holt, W. E.; Zhang, J. H.; Blewitt, G.; Yao, Z.

2017-12-01

Here we show, using 5-minute GPS data observed in northeast USA around the landfall of Hurricane Sandy of October 29-30, 2012, evidence of a highly-attenuated wave propagating in the Earth's crust over hundreds of km inland at 65 m/s with peak amplitudes as great as 12 cm. Such a phenomenon is consistent with Biot's slow wave being triggered by the associated 4-m storm surge, then propagating in a highly permeable crust with abundant fluid-saturated interconnected cracks. The vertical displacement field recorded on a dense network of continuous GPS stations (CORS network) shows strong attenuation with distance, and occurs at frequencies too low to be recorded by broad-band seismic sensors. To our knowledge, such a unique wave, with ultra-low frequency, slow wave speed, high amplitude, and strong attenuation, has never been measured before. The zenith tropospheric varies slowly over the 24 hours that bracket Hurricane Sandy landfall and there is no apparent relationship to the timing or duration of the downward displacement field that initiates during peak storm surge loading. Amplitudes are a factor of 10 higher than predicted by elastic models of static loading of the 4-m storm surge. Numerical simulations of a low frequency impulse (with duration of storm surge loading) on a homogenous porous medium filled with viscous fluid show an amplification of displacements 10 times larger than for a homogeneous elastic material with the same elastic properties as the poroelastic matrix. The low wave speed of 65 m/s and long period of 4 hours, requires an extremely high permeability (10-6 10-8 m2). Such a high permeability can exist in high-porosity media containing vast interconnected fractures. The high amplitude displacements generated by the dynamic influences of Hurricane Sandy, and other large magnitude storms, would generate significant time-dependent stress changes in the crust that might contribute to the observations of seismicity rate changes and slow slip phenomenon described previously for this and other major storm disturbances.

Massive pediatric neurosurgical injuries and lessons learned following a tornado disaster in Alabama.

PubMed

Chern, Joshua J; Miller, Joseph H; Tubbs, R Shane; Whisenhunt, Thomas R; Johnston, James M; Wellons, John C; Rozzelle, Curtis J; Blount, Jeffrey P; Oakes, W Jerry

2011-12-01

A large volume of patients presented to a Level I pediatric trauma center during and after a recent tornado disaster. Injuries of the central and peripheral nervous systems and the medical responses of a pediatric neurosurgical team are reviewed. The clinical courses of patients who suffered cranial, spinal, and peripheral nerve injuries due to the tornado storm are reported. The clinical actions taken by the neurosurgical team during and after the event are reviewed and the lessons learned are discussed. The tornado storm system moved through the Tuscaloosa and Birmingham metropolitan areas on the early evening hours of April 27, 2011. Twenty-four patients received care from the neurosurgical team. A total of 11 cranial (including placement of an external ventricular drain), 2 spine, and 2 peripheral procedures were performed for the victims. Nine procedures were performed within the first 12 hours of the event, and an additional 6 surgeries were performed in the following 24 hours. Injuries of the peripheral nervous system often presented in a delayed fashion. Several key components were identified that enabled adequate neurosurgical care for a large influx of acute patients. Massive casualties due to tornados are rare. A well-organized physician team working with the hospital administration may decrease the mortality and morbidity of such events.

2004 New Mexico traffic crash information

DOT National Transportation Integrated Search

2006-01-01

Severe weather conditions, i.e. snowfall, floods, ice storms, etc. can have major effects on traffic volumes along the highway network. Unlike passenger vehicles, which may choose not to travel during inclement weather, freight trucks need to adhere ...

Lightning Mapping Observations During DC3 in Northern Colorado

NASA Astrophysics Data System (ADS)

Krehbiel, P. R.; Rison, W.; Thomas, R. J.

2012-12-01

The Deep Convective Clouds and Chemistry Experiment (DC3) was conducted in three regions covered by Lightning Mapping Arrays (LMAs): Oklahoma and west Texas, northern Alabama, and northern Colorado. In this and a companion presentation, we discuss results obtained from the newly-deployed North Colorado LMA. The CO LMA revealed a surprising variety of lightning-inferred electrical structures, ranging from classic tripolar, normal polarity storms to several variations of anomalously electrified systems. Storms were often characterized by a pronounced lack or deficit of cloud-to-ground discharges (negative or positive), both in relative and absolute terms compared to the large amount of intracloud activity revealed by the LMA. Anomalous electrification was observed in small, localized storms as well as in large, deeply convective and severe storms. Another surprising observation was the frequent occurrence of embedded convection in the downwind anvil/outflow region of large storm systems. Observations of discharges in low flash rate situations over or near the network are sufficiently detailed to enable branching algorithms to estimate total channel lengths for modeling NOx production. However, this will not be possible in large or distant storm systems where the lightning was essentially continuous and structurally complex, or spatially noisy. Rather, a simple empirical metric for characterizing the lightning activity can be developed based on the number of located VHF radiation sources, weighted for example by the peak source power, source altitude, and temporal duration.

Objective Classification of Radar Profile Types, and Their Relationship to Lightning Occurrence

NASA Technical Reports Server (NTRS)

Boccippio, Dennis

2003-01-01

A cluster analysis technique is used to identify 16 "archetypal" vertical radar profile types from a large, globally representative sample of profiles from the TRMM Precipitation Radar. These include nine convective types (7 of these deep convective) and seven stratiform types (5 of these clearly glaciated). Radar profile classification provides an alternative to conventional deep convective storm metrics, such as 30 dBZ echo height, maximum reflectivity or VIL. As expected, the global frequency of occurrence of deep convective profile types matches satellite-observed total lightning production, including to very small scall local features. Each location's "mix" of profile types provides an objective description of the local convective spectrum, and in turn, is a first step in objectively classifying convective regimes. These classifiers are tested as inputs to a neural network which attempts to predict lightning occurrence based on radar-only storm observations, and performance is compared with networks using traditional radar metrics as inputs.

The likelihood of winter sprites over the Gulf Stream

NASA Astrophysics Data System (ADS)

Price, Colin; Burrows, William; King, Patrick

2002-11-01

With the recent introduction of the Canadian Lightning Detection Network (CLDN), it was revealed that during the winter months every year, the highest lightning activity within the network occurs over the Gulf Stream, southeast of Nova Scotia. These storms over the Gulf Stream, in addition to being of importance to trans-Atlantic shipping and aviation, have an unusually high fraction of positive polarity lightning, with unusually large peak currents. Such intense positive lightning flashes are known to generate transient luminous events (TLEs) such as sprites and elves in the upper atmosphere. It is found that many of these large positive discharges produce extremely low frequency (ELF) electromagnetic radiation detected at a field station in the Negev Desert, Israel, 8000 km away, in agreement with previously documented sprite observations. Since these winter storms occur in the same location every year, it provides a good opportunity for field experiments focused on studying winter sprites and oceanic thunderstorms.

The impact of climate change on transportation in the gulf coast

USGS Publications Warehouse

Savonis, M.J.; Burkett, V.R.; Potter, J.R.; Kafalenos, R.; Hyman, R.; Leonard, K.

2009-01-01

Climate affects the design, construction, safety, operations, and maintenance of transportation infrastructure and systems. The prospect of a changing climate raises critical questions regarding how alterations in temperature, precipitation, storm events, and other aspects of the climate could affect the nation's transportation system. This regional assessment of climate change and its potential impacts on transportation systems addresses these questions for the central Gulf Coast between Houston and Mobile. Warming temperatures are likely to increase the costs of transportation construction, maintenance, and operations. More frequent extreme precipitation events will likely disrupt transportation networks with flooding and visibility problems. Relative sea level rise will make much of the existing infrastructure more prone to frequent or permanent inundation. Increased storm intensity may lead to increased service disruption and damage. Consideration of these factors in today's transportation decisions should lead to a more robust, resilient, and cost-effective transportation network in the coming decades. ?? 2009 ASCE.

Using a Process Based Model to Simulate the Effects of Drainage and Land Use Change on Hydrology, and Sediment and Nutrient Transport in the Midwestern United States

NASA Astrophysics Data System (ADS)

Downer, C. W.; Pradhan, N. R.; Skahill, B. E.; Wahl, M.; Turnbull, S. J.

2015-12-01

Historically the Midwestern United State was a region dominated by prairie grasses and wetlands. To make use of the rich soils underlying these fertile environments, farmers converted the land to agriculture and currently the Midwest is a region of intensive agricultural production, with agriculture being a predominant land use. The Midwest is a region of gentle slopes, tight soils, and high water tables, and in order to make the lands suitable for agriculture, farmers have installed extensive networks of ditches to drain off excess surface water and subsurface tiles to lower the water table and remove excess soil water in the root zone that can stress common row crops, such as corn and soybeans. The combination of tiles, ditches, and intensive agricultural land practices radically alters the landscape and hydrology. As part of the Minnesota River Basin Integrated Study we are simulating nested watersheds in a sub-basin of the Minnesota River Basin, Seven Mile Creek, using the physics-based watershed model GSSHA (Gridded Surface Subsurface Hydrologic Analysis) to simulate water, sediment, and nutrients. Representative of the larger basin, more than 80% of the land in the watershed is dedicated to agricultural practices. From a process perspective, the hydrology is complicated, with snow accumulation and melt, frozen soil, and tile drains all being important processes within the watershed. In this study we attempt to explicitly simulate these processes, including the tile drains, which are simulated as a network of subsurface pipes that collect water from the local water table. Within the watershed, tiles discharge to both the ditch/stream network as well as overland locations, where the tile discharge appears to initiate gullies and exacerbate overland erosion. Testing of the methods on smaller basins demonstrates the ability of the model to simulate measured tile flow. At the larger scale, the model demonstrates ability to simulate flow and sediments. Sparse nutrient data limit the assessment of nutrient simulations. The models are being used to asses an array of potential future land use scenarios, including predevelopment and increased agricultural use. Results from these simulations will be presented. Preliminary results indicate that tile drains increase discharge and erosion in the watershed.

Dust storm from Syria- a potential new aerosol source in the E. Mediterranean- A ceilometer and synoptic study

NASA Astrophysics Data System (ADS)

Alpert, Pinhas; Egert, Smadar; Uzan, Leenes

2017-04-01

On 7 Sep 2015 an unprecedented huge dust plume approached the SE Mediterranean basin from the northeast- Syria region. According to the Israeli meteorological service it is the first time in 75 years of measurements, that a dust storm reaches Israel early September, lasts several days and dust concentrations reach values 100 times the normal (1700µg/m3). Dust storms are normally monitored in the east Mediterranean using satellites and surface PM data. Obviously, these cannot show the vertical evolution of the dust including penetration, sinking and cleaning since vertical profiles are not available. High-resolution, micro Lidar Ceilometer network is gradually established in Israel. A few instruments of this network were already operational during the dust storm. The most crucial vertical information, monitored by these Ceilometers with 10m resolution vertically, every 16s, is analyzed. The difference in the cloud-layers allow the investigation of the high altitude of 1000m dust penetration, its sinking into the complex structured 250-500m mixed layer and the gradual 3D cleaning. This finding contradicts the conventional understanding that cleaning is due to gradual descent and shows not only the vertical fluctuation during the entire event but also the vertical rise to 2000m at the end of the event. The vertical information showed that the actual event period duration was 7 days, compared to only 90 hours based on traditional detectors. Is it a new dust source in the E. Mediterranean-long and short term trends?

Storm generated large scale TIDs (LSTIDs): local, regional and global observations during solar cycles 23-24

NASA Astrophysics Data System (ADS)

Katamzi, Zama; Bosco Habarulema, John

2017-04-01

Large scale traveling ionospheric disturbances (LSTIDs) are a key dynamic ionospheric process that transports energy and momentum vertically and horizontally during storms. These disturbances are observed as electron density irregularities in total electron content and other ionospheric parameters. This study reports on various explorations of LSTIDs characteristics, in particular horizontal and vertical propagation, during some major/severe storms of solar cycles 23-24. We have employed GNSS TEC to estimate horizontal propagation and radio occultation data from COSMIC/FORMOSAT-3 and SWARM satellites to estimate vertical motion. The work presented here reveals the evolution of the characterisation efficiency from using sparsely populated stations, resulting in limited spatial resolution through rudimentary analysis to more densely populated GNSS network leading to more accurate temporal and spatial determinations. For example, early observations of LSTIDs largely revealed unidirectional propagation whereas later studies have showed that one storm can induce multi-directional propagation, e.g. Halloween 2003 storm induced equatorward LSTIDs on a local scale whereas the 9 March 2012 storm induced simultaneous equatorward and poleward LSTIDs on a global scale. This later study, i.e. 9 March 2012 storm, revealed for the first time that ionospheric electrodynamics, specifically variations in ExB drift, is also an efficient generator of LSTIDs. Results from these studies also revealed constructive and destructive interference pattern of storm induced LSTIDs. Constellations of LEO satellites such as COSMIC/FORMOSAT-3 and SWARM have given sufficient spatial and temporal resolution to study vertical propagation of LSTIDs in addition to the meridional propagation given by GNSS TEC; the former (i.e. vertical velocities) were found to fall below 100 m/s.

Monitoring storm tide and flooding from Hurricane Isaac along the Gulf Coast of the United States, August 2012

USGS Publications Warehouse

McCallum, Brian E.; McGee, Benton D.; Kimbrow, Dustin R.; Runner, Michael S.; Painter, Jaime A.; Frantz, Eric R.; Gotvald, Anthony J.

2012-01-01

The U.S. Geological Survey (USGS) deployed a temporary monitoring network of water-level and barometric pressure sensors at 127 locations along the gulf coast from Alabama to Louisiana to record the timing, areal extent, and magnitude of hurricane storm tide and coastal flooding generated by Hurricane Isaac. This deployment was undertaken as part of a coordinated federal emergency response as outlined by the Stafford Act under a directed mission assignment by the Federal Emergency Management Agency. Storm tide, as defined by National Oceanic and Atmospheric Administration (NOAA; National Oceanic and Atmospheric Administration, 2008), is the water-level rise generated by a combination of storm surge and astronomical tide during a coastal storm. Hurricane Isaac initially made landfall on the coast of Louisiana in Plaquemines Parish on August 28, 2012, as a Category 1 hurricane on the Saffir–Simpson Hurricane Wind Scale (National Weather Service, 1974) and then stalled over southern Louisiana for several days, causing prolonged storm-tide impacts. A total of 188 water-level and wave-height sensors were deployed at 127 locations during August 27–28 prior to landfall. More than 90 percent of the sensors and all high-water marks (HWMs) were recovered and surveyed to North American Vertical Datum of 1988 (NAVD 88) within 7 days of the Isaac landfall. Only a handful of sensors in the Plaquemines Parish area of Louisiana could not be retrieved until weeks later due to prolonged flooding in the area. Data collected from this event can be used to evaluate the performance of storm-tide models for maximum and incremental water level and flood extent and the site-specific effects of storm tide on natural and anthropogenic features of the environment.

Long-Range Lightning Products for Short Term Forecasting of Tropical Cyclogenesis

NASA Astrophysics Data System (ADS)

Businger, S.; Pessi, A.; Robinson, T.; Stolz, D.

2010-12-01

This paper will describe innovative graphical products derived in real time from long-range lightning data. The products have been designed to aid in short-term forecasting of tropical cyclone development for the Tropical Cyclone Structure Experiment 2010 (TCS10) held over the western Pacific Ocean from 17 August to 17 October 2010 and are available online at http://www.soest.hawaii.edu/cgi-bin/pacnet/tcs10.pl. The long-range lightning data are from Vaisala’s Global Lightning Data 360 (GLD360) network and include time, location, current strength, polarity, and data quality indication. The products currently provided in real time include i. Infrared satellite imagery overlaid with lighting flash locations, with color indication of current strength and polarity (shades of blue for negative to ground and red for positive to ground). ii. A 15x15 degree storm-centered tile of IR imagery overlaid with lightning data as in i). iii. A pseudo reflectivity product showing estimates of radar reflectivity based on lightning rate - rain rate conversion derived from TRMM and PacNet data. iv. A lightning history product that plots each hour of lightning flash locations in a different color for a 12-hour period. v. Graphs of lightning counts within 50 or 300 km radius, respectively, of the storm center vs storm central sea-level pressure. vi. A 2-D graphic showing storm core lightning density along the storm track. The first three products above can be looped to gain a better understanding of the evolution of the lightning and storm structure. Examples of the graphics and their utility will be demonstrated and discussed. Histogram of lightning counts within 50 km of the storm center and graph of storm central pressure as a function of time.

All-printed thin-film transistors from networks of liquid-exfoliated nanosheets

NASA Astrophysics Data System (ADS)

Kelly, Adam G.; Hallam, Toby; Backes, Claudia; Harvey, Andrew; Esmaeily, Amir Sajad; Godwin, Ian; Coelho, João; Nicolosi, Valeria; Lauth, Jannika; Kulkarni, Aditya; Kinge, Sachin; Siebbeles, Laurens D. A.; Duesberg, Georg S.; Coleman, Jonathan N.

2017-04-01

All-printed transistors consisting of interconnected networks of various types of two-dimensional nanosheets are an important goal in nanoscience. Using electrolytic gating, we demonstrate all-printed, vertically stacked transistors with graphene source, drain, and gate electrodes, a transition metal dichalcogenide channel, and a boron nitride (BN) separator, all formed from nanosheet networks. The BN network contains an ionic liquid within its porous interior that allows electrolytic gating in a solid-like structure. Nanosheet network channels display on:off ratios of up to 600, transconductances exceeding 5 millisiemens, and mobilities of >0.1 square centimeters per volt per second. Unusually, the on-currents scaled with network thickness and volumetric capacitance. In contrast to other devices with comparable mobility, large capacitances, while hindering switching speeds, allow these devices to carry higher currents at relatively low drive voltages.

Impervious surfaces and sewer pipe effects on stormwater runoff temperature

NASA Astrophysics Data System (ADS)

Sabouri, F.; Gharabaghi, B.; Mahboubi, A. A.; McBean, E. A.

2013-10-01

The warming effect of the impervious surfaces in urban catchment areas and the cooling effect of underground storm sewer pipes on stormwater runoff temperature are assessed. Four urban residential catchment areas in the Cities of Guelph and Kitchener, Ontario, Canada were evaluated using a combination of runoff monitoring and modelling. The stormwater level and water temperature were monitored at 10 min interval at the inlet of the stormwater management ponds for three summers 2009, 2010 and 2011. The warming effect of the ponds is also studied, however discussed in detail in a separate paper. An artificial neural network (ANN) model for stormwater temperature was trained and validated using monitoring data. Stormwater runoff temperature was most sensitive to event mean temperature of the rainfall (EMTR) with a normalized sensitivity coefficient (Sn) of 1.257. Subsequent levels of sensitivity corresponded to the longest sewer pipe length (LPL), maximum rainfall intensity (MI), percent impervious cover (IMP), rainfall depth (R), initial asphalt temperature (AspT), pipe network density (PND), and rainfall duration (D), respectively. Percent impervious cover of the catchment area (IMP) was the key parameter that represented the warming effect of the paved surfaces; sensitivity analysis showed IMP increase from 20% to 50% resulted in runoff temperature increase by 3 °C. The longest storm sewer pipe length (LPL) and the storm sewer pipe network density (PND) are the two key parameters that control the cooling effect of the underground sewer system; sensitivity analysis showed LPL increase from 345 to 966 m, resulted in runoff temperature drop by 2.5 °C.

2003 Mars Report from Cooperative Observation Networks. II. After the Opposition

NASA Astrophysics Data System (ADS)

Nakakushi, Takashi; Adachi, Makoto; Iga, Yuichi; Ikemura, Toshihiko; Tokimasa, Noritaka; Narumi, Yasunori

2005-06-01

This is the second report on Mars in 2003 by two networks for cooperative Mars observations in Japan: Nishi-Harima Astronomical Observatory Mars Cooperative Observation and Association of Lunar and Planetary Observers in Japan. This paper is a summary of 4145 data for 226 nights collected by the two networks during the second half of the last apparition from 2003 September 1 through 2004 June 22, corresponding to a period of Ls ˜ 252°--51° (Ls is the areocentric longitude of the Sun). During this period, many interesting phenomena were observed: (1) Albedo features did not show a large difference from the first half of the period. (2) Blue clearings due to the opposition effect and due to the cloud effect were, respectively, observed. (3) South polar cap (SPC) recession was usual. The recession rate in ˜ 210°--270°W increased and that in ˜ 30°--60°W decreased after Ls ˜ 230°. (4) North polar hood (NPH) had a topography-synchronous wave structure with a wave number = 1. (5) Many water ice clouds (WICs) were observed. Some particular regions frequently had prominent WICs. Some of them were related to topography. (6) Dust storm ``2003c'' was detected on December 9 (Ls = 314°) in Chryse. The storm grew rapidly to a very large dimension in the southern mid-latitudes, encircling over half of Mars. Another dust core occurred on December 23 around Aurorae Sinus. (7) Another dust storm is suspected in Ls = 20° over the south polar region.

Observation and Modeling of Storm Generated Acoustic Waves in the Ionosphere Revealed in a Dense Network of GPS Receivers

NASA Astrophysics Data System (ADS)

Walterscheid, R. L.; Azeem, S. I.

2017-12-01

Acoustic waves generated in the lower atmosphere may become an important source of variably in the upper atmosphere. Although they are excited with small amplitudes they are minimally subject to viscous dissipation and may reach significant amplitudes at F-region altitudes. A number of studies in the 1970s showed clear signatures in ionosonde data in the infrasonic period range attributable to thunder storm activity. We have examined Total Electron Content data from a dense network of over 4000 ground-based GPS receivers over the continental United States during an outbreak of severe weather, including tornados, over Kansas in May 2015. A sequence of GPS TEC images showed clear Traveling Ionospheric Disturbances (TIDs) in the form of concentric rings moving outward from the center of the storm region. The characteristics of the disturbance (phase speed and frequency) were consistent with acoustic waves in the infrasonic range. We have modeled the disturbance by including a tropospheric heat source representing latent heat release from a large thunderstorm. The disturbance at ionospheric altitudes resembles the observed disturbance in terms of phase speed, frequency and horizontal wavelength. We conclude that the observed TIDs in TEC were caused by an acoustic wave generated by deep convection.

Clusters of community exposure to coastal flooding hazards based on storm and sea level rise scenarios—implications for adaptation networks in the San Francisco Bay region

USGS Publications Warehouse

Hummel, Michelle; Wood, Nathan J.; Schweikert, Amy; Stacey, Mark T.; Jones, Jeanne; Barnard, Patrick L.; Erikson, Li H.

2018-01-01

Sea level is projected to rise over the coming decades, further increasing the extent of flooding hazards in coastal communities. Efforts to address potential impacts from climate-driven coastal hazards have called for collaboration among communities to strengthen the application of best practices. However, communities currently lack practical tools for identifying potential partner communities based on similar hazard exposure characteristics. This study uses statistical cluster analysis to identify similarities in community exposure to flooding hazards for a suite of sea level rise and storm scenarios. We demonstrate this approach using 63 jurisdictions in the San Francisco Bay region of California (USA) and compare 21 distinct exposure variables related to residents, employees, and structures for six hazard scenario combinations of sea level rise and storms. Results indicate that cluster analysis can provide an effective mechanism for identifying community groupings. Cluster compositions changed based on the selected societal variables and sea level rise scenarios, suggesting that a community could participate in multiple networks to target specific issues or policy interventions. The proposed clustering approach can serve as a data-driven foundation to help communities identify other communities with similar adaptation challenges and to enhance regional efforts that aim to facilitate adaptation planning and investment prioritization.

An 11-Year Climatology of Storms in Which Most Cloud-to-Ground Flashes Lower Positive Charge

NASA Astrophysics Data System (ADS)

MacGorman, D. R.; Eddy, A.; Williams, E. R.; Calhoun, K. M.

2017-12-01

Previous studies have shown that storms which produce frequent cloud-to-ground (CG) lightning dominated by flashes lowering positive charge to ground (+CG flashes) tend to have a so called "inverted" vertical distribution of charge. Such storms have implications for our understanding of electrification processes. We have analyzed eleven years of National Lightning Detection Network data to count +CG and -CG flashes having peak currents ≥15 kA in grid cells with dimensions of 15 km x 15 km x 15 min, with overlapping grid boxes every 5 km along both x and y over the contiguous United States and grids every 5 min in time. These dimensions were chosen because 15 km corresponds roughly to the horizontal size of typical storm cells and 15 min is roughly half the typical duration of a cell. To focus on storms dominated by +CG flashes, we identified all grid cells satisfying one of four sets of thresholds: cells in which +CG flashes for 15 min constitute ≥80%, 90%, or 100% of ≥10 CG flashes or 100% of ≥20 CG flashes. These percentages are larger than those used in most previous studies of +CG flashes. Our primary goal is to investigate the environmental and storm characteristics conducive to +CG flashes and "inverted-polarity" charge distributions, but here we concentrate on the interannual and seasonal distributions of storms satisfying the above thresholds and examine also their relationship to severe weather. As in previous climatological studies of geographic variations in the +CG fraction of total CG flashes, most storms satisfying our thresholds were in a swath stretching from far eastern Colorado and western Kansas roughly northward through Nebraska, the Dakotas, and Minnesota. This region overlaps much of the region in which radar inferred that hail larger than 2.9 cm in diameter most often occurs, but is shifted westward and northward from maxima of observer reports of large-hail occurrence. Although the relationship with radar-inferred large-hail frequency suggests a common dependence on some storm characteristics, storms satisfying our thresholds for +CG flashes also occurred, although less frequently, in regions in which few storms were inferred to have produced large hail, such as east of mountain ranges in northwestern states, so relationships with severe weather will need to be examined on a storm-by-storm basis.

Late Holocene Hurricane Activity in the Gulf of Mexico from a Bayou Sediment Archive

NASA Astrophysics Data System (ADS)

Rodysill, J. R.; Donnelly, J. P.; Toomey, M.; Sullivan, R.; MacDonald, D.; Evans, R. L.; Ashton, A. D.

2012-12-01

Hurricanes pose a considerable threat to coastal communities along the Atlantic seaboard and in the Gulf of Mexico. The complex role of ocean and atmospheric dynamics in controlling storm frequency and intensity, and how these relationships could be affected by climate change, remains uncertain. To better predict how storms will impact coastal communities, it is vital to constrain their past behavior, in particular how storm frequency and intensity and the pattern of storm tracks have been influenced by past climate conditions. In an effort to characterize past storm behavior, our work contributes to the growing network of storm records along the Atlantic and Gulf coasts by reconstructing storm-induced deposits in the northern Gulf of Mexico during the Late Holocene. Previous work on the northern Gulf coast has shown considerable centennial-scale variability in the occurrence of intense hurricanes, much like the northern Atlantic coast and in the Caribbean Sea. The timing of active and quiet intervals during the last 1000 years amongst the Gulf Coast records appears to be anti-phased with stormy intervals along the North American east coast. The sparse spatial coverage of the existing intense hurricane reconstructions provides a limited view of the natural variability of intense hurricanes. A new, high resolution reconstruction of storms along the northern Gulf Coast would be beneficial in assembling the picture of the patterns of storminess during the Late Holocene. Our study site, Basin Bayou, is situated on the north side of Choctawhatchee Bay in northwest Florida. From 1851 to 2011, 68 storms have struck the coast within 75 miles of Basin Bayou, of which 10 were Category 3 or greater, making it a prime location to reconstruct intense hurricanes. Basin Bayou openly exchanges water with Choctawhatchee Bay through a narrow channel, which acts as a conduit for propagating storm surges, and potentially coarse-grained bay sediments, into the bayou. Our record is constructed from grain size analyses and core density measurements on multiple cores from Basin Bayou. The upper sediments were dated with 210Pb and 137Cs techniques and compared with the historical record of storms. We observe substantial centennial-scale variability in the occurrence of storm-induced deposits in Basin Bayou over the last 1500 years that aligns considerably well with the temporal distribution of intense storms from preexisting Gulf Coast reconstructions.

Integrating Fluvial and Oceanic Drivers in Operational Flooding Forecasts for San Francisco Bay

NASA Astrophysics Data System (ADS)

Herdman, Liv; Erikson, Li; Barnard, Patrick; Kim, Jungho; Cifelli, Rob; Johnson, Lynn

2016-04-01

The nine counties that make up the San Francisco Bay area are home to 7.5 million people and these communties are susceptible to flooding along the bay shoreline and inland creeks that drain to the bay. A forecast model that integrates fluvial and oceanic drivers is necessary for predicting flooding in this complex urban environment. The U.S. Geological Survey ( USGS) and National Weather Service (NWS) are developing a state-of-the-art flooding forecast model for the San Francisco Bay area that will predict watershed and ocean-based flooding up to 72 hours in advance of an approaching storm. The model framework for flood forecasts is based on the USGS-developed Coastal Storm Modeling System (CoSMoS) that was applied to San Francisco Bay under the Our Coast Our Future project. For this application, we utilize Delft3D-FM, a hydrodynamic model based on a flexible mesh grid, to calculate water levels that account for tidal forcing, seasonal water level anomalies, surge and in-Bay generated wind waves from the wind and pressure fields of a NWS forecast model, and tributary discharges from the Research Distributed Hydrologic Model (RDHM), developed by the NWS Office of Hydrologic Development. The flooding extent is determined by overlaying the resulting water levels onto a recently completed 2-m digital elevation model of the study area which best resolves the extensive levee and tidal marsh systems in the region. Here we present initial pilot results of hindcast winter storms in January 2010 and December 2012, where the flooding is driven by oceanic and fluvial factors respectively. We also demonstrate the feasibility of predicting flooding on an operational time scale that incorporates both atmospheric and hydrologic forcings.

Cerro Grande Fire Impact to Water Quality and Stream Flow near Los Alamos National Laboratory: Results of Four Years of Monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

B.M. Gallaher; R.J. Koch

2004-09-15

In May 2000, the Cerro Grande fire burned about 7400 acres of mixed conifer forest on the Los Alamos National Laboratory (LANL), and much of the 10,000 acres of mountainside draining onto LANL was severely burned. The resulting burned landscapes raised concerns of increased storm runoff and transport of contaminants by runoff in the canyons traversing LANL. The first storms after the fire produced runoff peaks that were more than 200 times greater than prefire levels. Total runoff volume for the year 2000 increased 50% over prefire years, despite a decline in total precipitation of 13% below normal and amore » general decrease in the number of monsoonal thunderstorms. The majority of runoff in 2000 occurred in the canyons at LANL south of Pueblo Canyon (70%), where the highest runoff volume occurred in Water Canyon and the peak discharge occurred in Pajarito Canyon. This report describes the observed effects of the Cerro Grande fire and related environmental impacts to watersheds at and near Los Alamos National Laboratory (LANL) for the first four runoff seasons after the fire, from 2000 through 2003. Spatial and temporal trends in radiological and chemical constituents that were identified as being associated with the Cerro Grande fire and those that were identified as being associated with historic LANL discharges are evaluated with regard to impacts to the Rio Grande and area reservoirs downstream of LANL. The results of environmental sampling performed by LANL, the New Mexico Environment Department (NMED), and U.S. Geological Survey (USGS) after the Cerro Grande fire are included in the evaluation. Effects are described for storm runoff, baseflow, stream sediments, and area regional reservoir sediment.« less

Influence of climate change, tidal mixing, and watershed urbanization on historical water quality in Newport Bay, a saltwater wetland and tidal embayment in southern California.

PubMed

Pednekar, Abhishek M; Grant, Stanley B; Jeong, Youngsul; Poon, Ying; Oancea, Carmen

2005-12-01

Historical coliform measurements (n = 67,269; 32 years) in Newport Bay, a regionally important saltwater wetland and tidal embayment in southern California, have been compiled and analyzed. Coliform concentrations in Newport Bay decrease along an inland-to-ocean gradient, consistent with the hypothesis that this tidal embayment attenuates fecal pollution from inland sources. Nearly 70% of the variability in the coliform record can be attributed to seasonal and interannual variability in local rainfall, implying that stormwater runoff from the surrounding watershed is a primary source of coliform in Newport Bay. The storm loading rate of coliform from the San Diego Creek watershed--the largest watershed draining into Newport Bay--appears to be unaffected by the dramatic shift away from agricultural land-use that occurred in the watershed over the study period. Further, the peak loading of coliform during storms is larger than can be reasonably attributed to sources of human sewage, suggesting that nonhuman fecal pollution and/or bacterial regrowth contribute to the coliform load. Summer time measurements of coliform exhibit interannual trends, but these trends are site specific, apparently due to within-Bay variability in land-use, inputs of dry-weather runoff, and tidal mixing rates. Overall, these results suggest that efforts to improve water quality in Newport Bay will likely have greater efficacy during dry weather summer periods. Water quality during winter storms, on the other hand, appears to be dominated by factors outside of local management control; namely, virtually unlimited nonhuman sources of coliform in the watershed and global climate patterns, such as the El Nino Southern Oscillation, that modulate rainfall and stormwater runoff in southern California.

Holding Water in the Landscape; striking a balance between food production and healthy catchment function

NASA Astrophysics Data System (ADS)

Quinn, Paul; Wilkinson, Mark; Stutter, Marc; Adams, Russell

2015-04-01

Here it is proposed that ~5 % of the rural landscape could be modified to hold water during storm events. Hence ~95% of land remains for food production, commercial forestry and amenity. This is a catchment scale commitment to sustainably reducing flood and drought risk, improving water quality, biodiversity and thereby climate proofing our catchments. The farmed landscape has intensified and as a result, runoff rates are no longer in balance with the catchment needs, which in turn contributes to floods, droughts and water pollution problems. The loss of infiltration rates, soil water holding capacity and the increase in ditches and drains through intense farming has resulted in a reduction of the overall water holding capacity of the landscape, therefore deeper soil and aquifer recharge rates are lower. However, adequate raw water supply and food production is also vital. Here we consider how ~5% of productive land could be used to physically hold water during and after storms. This is a simple philosophy for water stewardship that could be delivered by farmers and land managers themselves. In this poster we consider a 'treatment train' of mitigation in headwaters by the construction of:- Rural SuDs - by creating swales, bunds and grassy filters; Buffer Strips - (designed to hold water); The Ditch of The Future - by creating the prime location for holding water and recovering lost top soil and finally the better use of Small Headwater Floodplains - by storing flood water, creating wetlands, planting new forest, installing woody debris and new habitats. We present examples of where and how these measures have been installed and show the cost-effectiveness of temporarily holding storm runoff in several case study catchments taken from the UK.

Moulin Migration and Development on the Greenland Ice Sheet

NASA Astrophysics Data System (ADS)

Chu, V. W.; Yang, L.

2017-12-01

Extensive river networks that terminate into moulins efficiently drain the surface of the Greenland ice sheet. These river moulins connect surface meltwater to englacial and subglacial drainage networks, where increased meltwater can enhance ice sliding dynamics. Previous moulin studies were limited to small geographic areas using field observations and/or high-resolution aerial/satellite imagery, or to medium-resolution satellite imagery for larger areas. In this study, high-resolution moulin maps created from WorldView-1/2/3 imagery near Russell Glacier in southwest Greenland show development of moulins and their migration between 2012 and 2015. Moulins are mapped and categorized as being located: in crevasse fields, along a single ice fracture, within drained lake basins, or having no visible formation mechanism. A majority of moulins mapped in 2015 (73%) are linked to moulins in 2012 and are analysed for their movement patterns and compared to ice velocity and strain rates. New moulins most commonly form in crevassed, thinner ice near the ice sheet edge, but significant quantities also develop at higher elevations (22% above 1300 m elevation).

Precipitation influences pathogenic bacteria and antibiotic resistance gene abundance in storm drain outfalls in coastal sub-tropical waters.

PubMed

Ahmed, Warish; Zhang, Qian; Lobos, Aldo; Senkbeil, Jacob; Sadowsky, Michael J; Harwood, Valerie J; Saeidi, Nazanin; Marinoni, Oswald; Ishii, Satoshi

2018-07-01

Stormwater contamination can threaten the health of aquatic ecosystems and human exposed to runoff via nutrient and pathogen influxes. In this study, the concentrations of 11 bacterial pathogens and 47 antibiotic resistance genes (ARGs) were determined by using high-throughput microfluidic qPCR (MFQPCR) in several storm drain outfalls (SDOs) during dry and wet weather in Tampa Bay, Florida, USA. Data generated in this study were also compared with the levels of fecal indicator bacteria (FIB) and sewage-associated molecular markers (i.e., Bacteroides HF183 and crAssphage markers) in same SDOs collected in a recent study (Ahmed et al., 2018). Concentration of FIB, sewage-associated markers, bacterial pathogens and many ARGs in water samples were relatively high and SDOs may be potentially hotspots for microbial contamination in Tampa Bay. Mean concentrations of culturable E. coli and Enterococcus spp. were tenfold higher in wet compared to dry weather. The majority of microbiological contaminants followed this trend. E. coli eaeA, encoding the virulence factor intimin, was correlated with levels of 20 ARGs, and was more frequently detected in wet weather than dry weather samples. The bla KPC gene associated with carbapenem resistant Enterobacteriaceae and the beta-lactam resistant gene (bla NPS ) were only detected in wet weather samples. Frequency of integron genes Intl2 and Intl3 detection increased by 42% in wet weather samples. Culturable E. coli and Enterococcus spp. significantly correlated with 19 of 47 (40%) ARG tested. Sewage-associated markers crAssphage and HF183 significantly correlated (p < 0.05) with the following ARGs: intl1, sul1, tet(M), ampC, mexB, and tet(W). The presence of sewage-associated marker genes along with ARGs associated with sewage suggested that aging sewage infrastructure contributed to contaminant loading in the Bay. Further research should focus on collecting spatial and temporal data on the microbiological contaminants especially viruses in SDOs. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Sources and export of particle-borne organic matter during a monsoon flood in a catchment of northern Laos

NASA Astrophysics Data System (ADS)

Gourdin, E.; Huon, S.; Evrard, O.; Ribolzi, O.; Bariac, T.; Sengtaheuanghoung, O.; Ayrault, S.

2015-02-01

The yields of the tropical rivers of Southeast Asia supply large quantities of carbon to the ocean. The origin and dynamics of particulate organic matter were studied in the Houay Xon River catchment located in northern Laos during the first erosive flood of the rainy season in May 2012. This cultivated catchment is equipped with three successive gauging stations draining areas ranging between 0.2 and 11.6 km2 on the main stem of the permanent stream, and two additional stations draining 0.6 ha hillslopes. In addition, the sequential monitoring of rainwater, overland flow and suspended organic matter compositions was conducted at the 1 m2 plot scale during a storm. The composition of particulate organic matter (total organic carbon and total nitrogen concentrations, δ13C and δ15N) was determined for suspended sediment, soil surface (top 2 cm) and soil subsurface (gullies and riverbanks) samples collected in the catchment (n = 57, 65 and 11, respectively). Hydrograph separation of event water was achieved using water electric conductivity and δ18O measurements for rainfall, overland flow and river water base flow (n = 9, 30 and 57, respectively). The composition of particulate organic matter indicates that upstream suspended sediments mainly originated from cultivated soils labelled by their C3 vegetation cover (upland rice, fallow vegetation and teak plantations). In contrast, channel banks characterized by C4 vegetation (Napier grass) supplied significant quantities of sediment to the river during the flood rising stage at the upstream station as well as in downstream river sections. The highest runoff coefficient (11.7%), sediment specific yield (433 kg ha-1), total organic carbon specific yield (8.3 kg C ha-1) and overland flow contribution (78-100%) were found downstream of reforested areas planted with teaks. Swamps located along the main stream acted as sediment filters and controlled the composition of suspended organic matter. Total organic carbon specific yields were particularly high because they occurred during the first erosive storm of the rainy season, just after the period of slash-and-burn operations in the catchment.

Mercury and Methylmercury Related to Historical Mercury Mining in Three Major Tributaries to Lake Berryessa, Upper Putah Creek Watershed, California

NASA Astrophysics Data System (ADS)

Sparks, G. C.; Alpers, C. N.; Horner, T. C.; Cornwell, K.; Izzo, V.

2016-12-01

The relative contributions of total mercury (THg) and methylmercury (MeHg) from upstream historical mercury (Hg) mining districts were examined in the three largest tributaries to Lake Berryessa, a reservoir with water quality impaired by Hg. A fish consumption advisory has been issued for the reservoir; also, in a study of piscivorous birds at 25 California reservoirs, blood samples from Lake Berryessa grebes had the highest THg concentration state-wide. The third and fourth largest historical Hg-producing mining districts in California are within the study area. These mining districts are located within the Pope Creek, Upper Putah Creek, and Knoxville-Eticuera Creeks watersheds. Downstream of the reservoir, Lower Putah Creek drains into the Yolo Bypass, a major source of THg and MeHg to the Sacramento-San Joaquin Delta. Study objectives included: (1) determining if tributaries downstream of historical Hg mining districts and draining to the reservoir are continuing sources of THg and MeHg; (2) characterizing variability of water and streambed sediment parameters in upstream and downstream reaches of each creek; and (3) estimating loads of suspended sediment, THg, and MeHg entering the reservoir from each tributary. Water samples were collected from October 2012 to September 2014 during non-storm and storm events along each tributary and analyzed for general water quality field parameters; unfiltered THg and MeHg; total suspended solids; and total particulate matter. Discharge measurements were made at the time of sample collection; flow and concentration data were combined to compute daily loads. To determine spatial variability, 135 streambed sediment samples were analyzed for THg, organic content (loss on ignition), and grain-size distribution. All three tributaries contribute THg and MeHg to the reservoir. Some consistent spatial trends in THg (water) concentrations were observed over multiple sampling events; THg (water) decreased from upstream to downstream in all three tributaries. Tributary reaches with elevated THg in streambed sediment ("Hg hot spots") are near or downstream from historical Hg mines and Hg-enriched ore deposits. Future Hg load and cycling studies are needed to identify practical remediation approaches for decreasing THg and MeHg loads to Lake Berryessa.

Formation and evolution of a drainage network during the Pleistocene through a process of homoclinal shifting initiated by headward erosion.

NASA Astrophysics Data System (ADS)

Castelltort, F. Xavier; Carles Balasch, J.; Cirés, Jordi; Colombo, Ferran

2017-04-01

A homoclinal shifting process in NE of the Ebro basin, NE Iberian Peninsula, reorganized an old flow network into a new one. This process was initiated by the reactivation of a major normal fault (Amer Fault). An anaclinal stream, flowing to the hanging wall block, incised in the fault-line scarp, accessing by headward erosion the less resistant Paleogene units. The result was the formation of a sequence of strike valleys. The first valleys are situated in a more elevated topographical position than the valleys formed later. The last and the most important valley is La Plana de Vic, which is being emptied by differential erosion in front of the resistant base layer. The study of the lateral migration of a drainage basin since its initial stages has allowed the recognition of the layout of a drainage network and its model of evolution. The new drainage network includes three different subsystems. The main subsystem consists of stream courses flowing along the strike valley. While the other two subsystems flow into the main or can flow directly to the basin sink. These are the anaclinal subsystem, which drains the scarp face of the asymmetric valley, and the cataclinal subsystem, which drains the cuesta. The process of homoclinal shifting makes the strike streams migrate laterally and dip in the less resistant unit. This migration implies the reorganization of the other two tributary subsystems. The sequence of reorganizations may be preserved on the resistant bedrock of the cuesta. This allows the reconstruction of the route of the headward erosion of the initial anaclinal stream course through remnants of ancient strike streams flowing into former basin sinks, and its cataclinal tributaries draining the cuesta. In the case study of La Plana de Vic the migration route of the basin sink can be reconstructed from its initial position, Early Pleistocene, until present day. Besides, reorganization of the cataclinal network can also be recognized. During the lateral migration three incisions were made in a large anticlinal structure in the north (Bellmunt Anticline) and one incision was made in a crystalline massif (Montseny) in the south. The last of the incisions into the Bellmunt Anticline captured by headward erosion an older drainage network with headwaters in the axial Pyrenees. The result of the homoclinal shifting process was the capture of older drainage basins and the formation of the current drainage basin of the river Ter.

Monitoring storm tide and flooding from Hurricane Matthew along the Atlantic coast of the United States, October 2016

USGS Publications Warehouse

Frantz, Eric R.; Byrne,, Michael L.; Caldwell, Andral W.; Harden, Stephen L.

2017-11-02

IntroductionHurricane Matthew moved adjacent to the coasts of Florida, Georgia, South Carolina, and North Carolina. The hurricane made landfall once near McClellanville, South Carolina, on October 8, 2016, as a Category 1 hurricane on the Saffir-Simpson Hurricane Wind Scale. The U.S. Geological Survey (USGS) deployed a temporary monitoring network of storm-tide sensors at 284 sites along the Atlantic coast from Florida to North Carolina to record the timing, areal extent, and magnitude of hurricane storm tide and coastal flooding generated by Hurricane Matthew. Storm tide, as defined by the National Oceanic and Atmospheric Administration, is the water-level rise generated by a combination of storm surge and astronomical tide during a coastal storm.The deployment for Hurricane Matthew was the largest deployment of storm-tide sensors in USGS history and was completed as part of a coordinated Federal emergency response as outlined by the Stafford Act (Public Law 92–288, 42 U.S.C. 5121–5207) under a directed mission assignment by the Federal Emergency Management Agency. In total, 543 high-water marks (HWMs) also were collected after Hurricane Matthew, and this was the second largest HWM recovery effort in USGS history after Hurricane Sandy in 2012.During the hurricane, real-time water-level data collected at temporary rapid deployment gages (RDGs) and long-term USGS streamgage stations were relayed immediately for display on the USGS Flood Event Viewer (https://stn.wim.usgs.gov/FEV/#MatthewOctober2016). These data provided emergency managers and responders with critical information for tracking flood-effected areas and directing assistance to effected communities. Data collected from this hurricane can be used to calibrate and evaluate the performance of storm-tide models for maximum and incremental water level and flood extent, and the site-specific effects of storm tide on natural and anthropogenic features of the environment.

Developing Empirical Lightning Cessation Forecast Guidance for the Cape Canaveral Air Force Station and Kennedy Space Center

NASA Technical Reports Server (NTRS)

Stano, Geoffrey T.; Fuelberg, Henry E.; Roeder, William P.

2010-01-01

This research addresses the 45th Weather Squadron's (45WS) need for improved guidance regarding lightning cessation at Cape Canaveral Air Force Station and Kennedy Space Center (KSC). KSC's Lightning Detection and Ranging (LDAR) network was the primary observational tool to investigate both cloud-to-ground and intracloud lightning. Five statistical and empirical schemes were created from LDAR, sounding, and radar parameters derived from 116 storms. Four of the five schemes were unsuitable for operational use since lightning advisories would be canceled prematurely, leading to safety risks to personnel. These include a correlation and regression tree analysis, three variants of multiple linear regression, event time trending, and the time delay between the greatest height of the maximum dBZ value to the last flash. These schemes failed to adequately forecast the maximum interval, the greatest time between any two flashes in the storm. The majority of storms had a maximum interval less than 10 min, which biased the schemes toward small values. Success was achieved with the percentile method (PM) by separating the maximum interval into percentiles for the 100 dependent storms.

Large-scale traveling ionospheric disturbances using ionospheric imaging at storm time: A case study on 17 march 2013

NASA Astrophysics Data System (ADS)

Tang, Jun; Yao, Yibin; Kong, Jian; Zhang, Liang

2016-07-01

A moderate geomagnetic storm occurred on March 17, 2013, during which large-scale traveling ionospheric disturbances (LSTIDs) are observed over China by ionosondes and GPS from Crustal Movement Observation Network of China (CMONOC) and the International GNSS Service (IGS). Ionosonde data and computerized ionospheric tomography (CIT) technique are employed to analyze the disturbances in our study. The maximum entropy cross spectral analysis (MECSA) method is used to obtain the propagation parameters of the LSTIDs. Spatio-temporal variations of ionospheric electron density (IED) and total electron content (TEC) during this geomagnetic storm over China are investigated. Disturbance images of IED and TEC are also presented in the paper. The results show two LSTID events at about 12:00 UT and 15:00 UT during the main phase of the storm. Besides, the LSTIDs with a duration of 40 min are detected over China. It is confirmed that the LSTIDs travel from north to south with a horizontal velocity of 400-500 m/s, and moved southwestwards with a horizontal velocity of 250-300 m/s, respectively.

Contrasting Patterns of Fine Fluvial Sediment Delivery in Two Adjacent Upland Catchments

NASA Astrophysics Data System (ADS)

Perks, M.; Bracken, L.; Warburton, J.

2010-12-01

Quantifying patterns of fine suspended sediment transfer in UK upland rivers is of vital importance in combating the damaging effects of elevated fluxes of suspended sediment, and sediment associated transport of contaminants, on in-stream biota. In many catchments of the UK there is still a lack of catchment-wide understanding of both the spatial patterns and temporal variation in fine sediment delivery. This poster describes the spatial and temporal distribution of in-stream fine sediment delivery from a network of 44 time-integrated mass flux samplers (TIMs) in two adjacent upland catchments. The two catchments are the Esk (210 km2) and Upper Derwent (236 km2) which drain the North York Moors National Park. Annual suspended sediment loads in the Upper Derwent are 1273 t, whereas in the Esk catchment they are greater at 1778 t. Maximum yields of 22 t km-2 yr -1 were measured in the headwater tributaries of the Rye River (Derwent), whereas peak yields in the Esk are four times greater (98 t km-2 yr-1) on the Butter Beck subcatchment. Analysis of the within-storm sediment dynamics, indicates that the sediment sources within the Upper Derwent catchment are from distal locations possibly mobilised by hillslope runoff processes, whereas in the Esk, sediment sources are more proximal to the channel e.g. within channel stores or bank failures. These estimates of suspended sediment flux are compared with the diffuse pollution potential generated by a risk-based model of sediment transfer (SCIMAP) in order to assess the similarity between the model predictions and observed fluxes.

Lightning Sensors for Observing, Tracking and Nowcasting Severe Weather

PubMed Central

Price, Colin

2008-01-01

Severe and extreme weather is a major natural hazard all over the world, often resulting in major natural disasters such as hail storms, tornados, wind storms, flash floods, forest fires and lightning damages. While precipitation, wind, hail, tornados, turbulence, etc. can only be observed at close distances, lightning activity in these damaging storms can be monitored at all spatial scales, from local (using very high frequency [VHF] sensors), to regional (using very low frequency [VLF] sensors), and even global scales (using extremely low frequency [ELF] sensors). Using sensors that detect the radio waves emitted by each lightning discharge, it is now possible to observe and track continuously distant thunderstorms using ground networks of sensors. In addition to the number of lightning discharges, these sensors can also provide information on lightning characteristics such as the ratio between intra-cloud and cloud-to-ground lightning, the polarity of the lightning discharge, peak currents, charge removal, etc. It has been shown that changes in some of these lightning characteristics during thunderstorms are often related to changes in the severity of the storms. In this paper different lightning observing systems are described, and a few examples are provided showing how lightning may be used to monitor storm hazards around the globe, while also providing the possibility of supplying short term forecasts, called nowcasting. PMID:27879700

Intensified dust storm activity and Valley fever infection in the southwestern United States

NASA Astrophysics Data System (ADS)

Tong, Daniel Q.; Wang, Julian X. L.; Gill, Thomas E.; Lei, Hang; Wang, Binyu

2017-05-01

Climate models have consistently projected a drying trend in the southwestern United States, aiding speculation of increasing dust storms in this region. Long-term climatology is essential to documenting the dust trend and its response to climate variability. We have reconstructed long-term dust climatology in the western United States, based on a comprehensive dust identification method and continuous aerosol observations from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network. We report here direct evidence of rapid intensification of dust storm activity over American deserts in the past decades (1988-2011), in contrast to reported decreasing trends in Asia and Africa. The frequency of windblown dust storms has increased 240% from 1990s to 2000s. This dust trend is associated with large-scale variations of sea surface temperature in the Pacific Ocean, with the strongest correlation with the Pacific Decadal Oscillation. We further investigate the relationship between dust and Valley fever, a fast-rising infectious disease caused by inhaling soil-dwelling fungus (Coccidioides immitis and C. posadasii) in the southwestern United States. The frequency of dust storms is found to be correlated with Valley fever incidences, with a coefficient (r) comparable to or stronger than that with other factors believed to control the disease in two endemic centers (Maricopa and Pima County, Arizona).

Analysis of the monitoring data of geomagnetic storm interference in the electrification system of a high-speed railway

NASA Astrophysics Data System (ADS)

Liu, Lianguang; Ge, Xiaoning; Zong, Wei; Zhou, You; Liu, Mingguang

2016-10-01

To study the impact of geomagnetic storm on the equipment of traction electrification system in the high-speed railway, geomagnetically induced current (GIC) monitoring devices were installed in the Hebi East traction power supply substation of the Beijing-Hong Kong Dedicated Passenger Line in January 2015, and GICs were captured during the two geomagnetic storms on 17 March and 23 June 2015. In order to investigate the GIC flow path, both in the track circuit and in the traction network adopting the autotransformer feeding system, a GIC monitor plan was proposed for the electrical system in the Hebi East traction power supply substation. This paper analyzes the correlation between the GIC captured on 17 March and the geomagnetic data obtained from the Malingshan Geomagnetic Observatory and presents a regression analysis between the measured GIC and the calculated geoelectric fields on 23 June in the high-speed railway. The maximum GICs measured in the track circuit are 1.08 A and 1.74 A during the two geomagnetic storms. We find that it is necessary to pay attention on the throttle transformers and track circuits, as the most sensitive elements responding to the extreme geomagnetic storms in the high-speed railway.

Coastal Applications of the Canopy Biomass Lidar (CBL)

NASA Astrophysics Data System (ADS)

Paynter, I.; Saenz, E.; Peri, F.; Schaaf, C.; Wang, Z.; Erb, A.; Yang, Y.; Rouhani, S.; Liu, Y.; Yang, X.; Chen, R. F.; Oktay, S.; Gontz, A. M.; Douglas, E. M.; Kim, J.; Sun, Q.; Strahler, A. H.; Li, Z.; van Aardt, J. A.; Kelbe, D.; Romanczyk, P.; Cawse-Nicholson, K.

2013-12-01

Airborne discrete and full waveform lidars have increasingly been utilized to augment multispectral and hyperspectral imaging of coastal ecosystems. While these data provide important landscape assessments of the shore and nearshore environment, they often lack the frequency that is really needed to monitor complex vegetative systems such as salt marshes and mangroves and provide rapid evaluations in the aftermath of severe storms. One solution is to augment the sparse airborne and satellite acquisitions with terrestrial laser scanning (TLS) information. However, most institutions with fine resolution discrete or full waveform TLS instruments are unwilling to risk these expensive (and often heavy) lidar in marine or estuarine environments. The Canopy Biomass Lidar (CBL) is an inexpensive, highly portable, fast-scanning, time-of-flight, TLS instrument, originally conceived by the Katholieke Universiteit Leuven (KUL) and refined by the Rochester Institute of Technology (RIT). Two new CBLs, constructed by the University of Massachusetts Boston (UMB), have been successfully deployed in deciduous and conifer forests at Long Term Ecological Research (LTER) and National Ecological Observatory Network (NEON) sites in Massachusetts (Harvard Forest) and California (Sierra National Forest), and in eucalypt forests at long-term and Terrestrial Ecosystem Research Network (TERN) sites in Queensland, Australia. Both the UMB and RIT CBLs have also been deployed in savanna systems at the San Joaquin Rangeland (and NEON site) in California. The UMB CBLs are now being deployed in salt marsh systems in Massachusetts with plans underway to deploy them in mangrove forests later in the year. In particular, they are being used to characterize the water facing edge of saltmarsh at UMB's Nantucket Island field station and remnant salt marshes on the highly urbanized Neponset estuary draining into Boston Harbor. While CBL's 905nm nearIR wavelength is of little use in nearshore inundated systems (such as eel grass and kelp), it is excellent for characterizing 3D foliage structure via multiple scan point clouds. The system is light and the scanning is rapid enough (30seconds for a full hemispherical scan) to be deployed manually or in small watercraft. The portability also means that it can be used frequently to monitor vegetation dynamics throughout the growing season and assess marsh damage and erosion after severe storms. While airborne lidar and hyperspectral data and high resolution satellite imagery (and indeed even the more frequently available coarser resolution multispectral satellite imagery from the newly launched Landsat 8) will provide the most expansive views of such environments, tools such as the CBL can provide important ancillary information to augment the remote sensing data and provide rapid and fine scale shore level details to improve modeling and monitoring of these coastal vegetation ecosystems.

Prediction of phosphorus loads in an artificially drained lowland catchment using a modified SWAT model

NASA Astrophysics Data System (ADS)

Bauwe, Andreas; Eckhardt, Kai-Uwe; Lennartz, Bernd

2017-04-01

Eutrophication is still one of the main environmental problems in the Baltic Sea. Currently, agricultural diffuse sources constitute the major portion of phosphorus (P) fluxes to the Baltic Sea and have to be reduced to achieve the HELCOM targets and improve the ecological status. Eco-hydrological models are suitable tools to identify sources of nutrients and possible measures aiming at reducing nutrient loads into surface waters. In this study, the Soil and Water Assessment Tool (SWAT) was applied to the Warnow river basin (3300 km2), the second largest watershed in Germany discharging into the Baltic Sea. The Warnow river basin is located in northeastern Germany and characterized by lowlands with a high proportion of artificially drained areas. The aim of this study were (i) to estimate P loadings for individual flow fractions (point sources, surface runoff, tile flow, groundwater flow), spatially distributed on sub-basin scale. Since the official version of SWAT does not allow for the modeling of P in tile drains, we tested (ii) two different approaches of simulating P in tile drains by changing the SWAT source code. The SWAT source code was modified so that (i) the soluble P concentration of the groundwater was transferred to the tile water and (ii) the soluble P in the soil was transferred to the tiles. The SWAT model was first calibrated (2002-2011) and validated (1992-2001) for stream flow at 7 headwater catchments at a daily time scale. Based on this, the stream flow at the outlet of the Warnow river basin was simulated. Performance statistics indicated at least satisfactory model results for each sub-basin. Breaking down the discharge into flow constituents, it becomes visible that stream flow is mainly governed by groundwater and tile flow. Due to the topographic situation with gentle slopes, surface runoff played only a minor role. Results further indicate that the prediction of soluble P loads was improved by the modified SWAT versions. Major sources of P in rivers are groundwater and tile flow. P was also released by surface runoff during large storm events when sediment was eroded into the rivers. The contributions of point sources in terms of waste water treatment plants to the overall P loading were low. The modifications made in the SWAT source code should be considered as a starting point to simulate P loads in artificially drained landscapes more precisely. Further testing and development of the code is required.

Effects of highway runoff on streamflow and water quality in the Sevenmile Creek basin, a rural area in the Piedmont Province of North Carolina, July 1981 to July 1982

USGS Publications Warehouse

Harned, Douglas

1988-01-01

An evaluation of water-quality data from streams that receive stormwater runoff from a segment of Interstate Highway 85 in North Carolina indicated increased levels of many constituents compared to levels in nearby undeveloped basins. Additional data collected from a network of dry and wet atmospheric deposition collectors, lysimeter samples, soil surveys, wind measurements, and road sweepings helped define the general sources and migration of chemical substances near the highway. The eight study basins, located in a rural area in the Piedmont of North Carolina, had a combined area of 17.5 square miles and drained a 4.8-mile-long segment of the interstate. The average traffic flow along this section was 25,000 vehicles per day. During storm runoff, streamflow in basins traversed by the highway rose and fell more rapidly than that in the undeveloped basins. This more rapid response is due to the impervious, paved area of the basins and the manmade drainage systems designed to rapidly move water off the highway. Alkalinity, specific conductance, and concentrations of calcium, sodium, and chloride were greater at the highway stations than in the undeveloped basins as a result of highway salting for control of ice. Specific conductance and concentrations of dissolved and total nitrogen peaked at the beginning of each storm event. The data indicated that, for the study basins, highway runoff had little or no effect on suspended sediment, water temperature, dissolved oxygen, and pH. However, the pH at all stations decreased during stormflow because the rainfall drained off by the streams had pH values less than 5.7. High metals concentrations were found in the soils within 100 feet of the highway and in the soil water infiltrating the soil zone. Chromium, copper, nickel, and zinc concentrations in the streams near the highway generally were above the maximum levels recommended by the U.S. Environmental Protection Agency (EPA) for the protection of aquatic life. Lead and cadmium concentrations frequently exceeded the maximum levels recommended by the EPA for drinking water. The highway is a source of contaminants to surrounding areas. Particulate and metal loads in dustfall and chemical-constituent concentrations in soils decrease exponentially with distance from the highway. The highest concentrations of contaminants were found on the downwind side. Increased concentrations of metals (cadmium, chromium, iron, lead, nickel, and zinc) in rainfall were observed in samples collected near the highway and in samples collected approximately one-half mile away. Material loading due to dustfall was greater than loading due to rainfall. Loading due to saltated particles, those heavier particles bounced along the highway surface, was higher than loading due to dustfall. Saltation loads were greatest during the winter months because of highway deicing and sanding, which supplied an estimated two-thirds of the saltated materials. The remaining one-third of the saltated load came primarily from the deposition of particles from vehicles. Some of the greatest constituent concentrations were measured in the soil water sampled from the lysimeters located adjacent to the highway.

Simulation of streamflow and water quality in the Brandywine Creek subbasin of the Christina River basin, Pennsylvania and Delaware, 1994-98

USGS Publications Warehouse

Senior, Lisa A.; Koerkle, Edward H.

2003-01-01

The Christina River Basin drains 565 mi2 (square miles) in Pennsylvania and Delaware. Water from the basin is used for recreation, drinking-water supply, and to support aquatic life. The Christina River Basin includes the major subbasins of Brandywine Creek, Red Clay Creek, White Clay Creek, and Christina River. The Brandywine Creek is the largest of the subbasins and drains an area of 327 mi2. Water quality in some parts of the Christina River Basin is impaired and does not support designated uses of the streams. A multi-agency water-quality management strategy included a modeling component to evaluate the effects of point and nonpoint-source contributions of nutrients and suspended sediment on streamwater quality. To assist in nonpoint-source evaluation, four independent models, one for each of the four main subbasins of the Christina River Basin, were developed and calibrated using the model code Hydrological Simulation Program—Fortran (HSPF). Water-quality data for model calibration were collected in each of the four main subbasins and in small subbasins predominantly covered by one land use following a nonpoint-source monitoring plan. Under this plan, stormflow and base-flow samples were collected during 1998 at six sites in the Brandywine Creek subbasin and five sites in the other subbasins.The HSPF model for the Brandywine Creek Basin simulates streamflow, suspended sediment, and the nutrients, nitrogen and phosphorus. In addition, the model simulates water temperature, dissolved oxygen, biochemical oxygen demand, and plankton as secondary objectives needed to support the sediment and nutrient simulations. For the model, the basin was subdivided into 35 reaches draining areas that ranged from 0.6 to 18 mi2. Three of the reaches contain regulated reservoir. Eleven different pervious land uses and two impervious land uses were selected for simulation. Land-use areas were determined from 1995 land-use data. The predominant land uses in the basin are forested, agricultural, residential, and urban. The hydrologic component of the model was run at an hourly time step and calibrated using streamflow data for eight U.S. Geological Survey (USGS) stream-flow-measurement stations for the period of January 1, 1994, through October 29, 1998. Daily precipitation data for three National Oceanic and Atmospheric Administration (NOAA) gages and hourly data for one NOAA gage were used for model input. The difference between observed and simulated streamflow volume ranged from -2.7 to 3.9 percent for the nearly 5-year period at the eight calibration sites. Annual differences between observed and simulated streamflow generally were greater than the overall error. For example, at a site near the bottom of the basin (drainage area of 237 mi2), annual differences between observed and simulated streamflow ranged from -14.0 to 18.8 percent and the overall error for the 5-year period was 1.0 percent. Calibration errors for 36 storm periods at the eight calibration sites for total volume, low-flow-recession rate, 50-percent lowest flows, 10-percent highest flows, and storm peaks were within the recommended criteria of 20 percent or less. Much of the error in simulating storm events on an hourly time step can be attributed to uncertainty in the rainfall data.The water-quality component of the model was calibrated using monitoring data collected at six USGS streamflow-measurement stations with variable water quality monitoring periods ending October 1998. Because of availability, monitoring data for suspended solids concentrations were used as surrogates for suspended-sediment concentrations, although suspended-solids data may underestimate suspended sediment and affect apparent accuracy of the suspended-sediment simulation. Comparison of observed to simulated loads for two to six individual storms in 1998 at each of the six monitoring sites indicate that simulation error is commonly as large as an order of magnitude for suspended sediment and nutrients. The simulation error tends to be smaller for dissolved nutrients than for particulate nutrients. Errors of 40 percent or less for monthly or annual values indicate a fair to good water-quality calibration according to recommended criteria, with much larger errors possible for individual events. Assessment of the water-quality calibration under stormflow conditions is limited by the relatively small amount of available water-quality data in the basin. Duration curves for simulated and reported sediment concentration at Brandywine Creek at Wilmington, Del., are similar, indicating model performance is better when evaluated over longer periods than when evaluated on individual storm events.

Toward an integrated storm surge application: ESA Storm Surge project

NASA Astrophysics Data System (ADS)

Lee, Boram; Donlon, Craig; Arino, Olivier

2010-05-01

Storm surges and their associated coastal inundation are major coastal marine hazards, both in tropical and extra-tropical areas. As sea level rises due to climate change, the impact of storm surges and associated extreme flooding may increase in low-lying countries and harbour cities. Of the 33 world cities predicted to have at least 8 million people by 2015, at least 21 of them are coastal including 8 of the 10 largest. They are highly vulnerable to coastal hazards including storm surges. Coastal inundation forecasting and warning systems depend on the crosscutting cooperation of different scientific disciplines and user communities. An integrated approach to storm surge, wave, sea-level and flood forecasting offers an optimal strategy for building improved operational forecasts and warnings capability for coastal inundation. The Earth Observation (EO) information from satellites has demonstrated high potential to enhanced coastal hazard monitoring, analysis, and forecasting; the GOCE geoid data can help calculating accurate positions of tide gauge stations within the GLOSS network. ASAR images has demonstrated usefulness in analysing hydrological situation in coastal zones with timely manner, when hazardous events occur. Wind speed and direction, which is the key parameters for storm surge forecasting and hindcasting, can be derived by using scatterometer data. The current issue is, although great deal of useful EO information and application tools exist, that sufficient user information on EO data availability is missing and that easy access supported by user applications and documentation is highly required. Clear documentation on the user requirements in support of improved storm surge forecasting and risk assessment is also needed at the present. The paper primarily addresses the requirements for data, models/technologies, and operational skills, based on the results from the recent Scientific and Technical Symposium on Storm Surges (www.surgesymposium.org, organized by the WMO-IOC Joint technical Commission for Oceanography and Marine Meteorology, JCOMM) and following activities, that have been supported by the Intergovernmental Oceanographic Commission (IOC) of UNESCO through JCOMM. The paper also reviews the capabilities of storm surge models, and current status in using Earth Observation (EO) information for advancing storm surge application tools, and further, for improving operational forecasts and warning capability for coastal inundation. In this context, the plans and expected results of the ESA Storm Surge Project (2010-2011) will be introduced.

Nitrous oxide emission from denitrification in stream and river networks

USGS Publications Warehouse

Beaulieu, J.J.; Tank, J.L.; Hamilton, S.K.; Wollheim, W.M.; Hall, R.O.; Mulholland, P.J.; Peterson, B.J.; Ashkenas, L.R.; Cooper, L.W.; Dahm, Clifford N.; Dodds, W.K.; Grimm, N. B.; Johnson, S.L.; McDowell, W.H.; Poole, G.C.; Maurice, Valett H.; Arango, C.P.; Bernot, M.J.; Burgin, A.J.; Crenshaw, C.L.; Helton, A.M.; Johnson, L.T.; O'Brien, J. M.; Potter, J.D.; Sheibley, R.W.; Sobota, D.J.; Thomas, S.M.

2011-01-01

Nitrous oxide (N2O) is a potent greenhouse gas that contributes to climate change and stratospheric ozone destruction. Anthropogenic nitrogen (N) loading to river networks is a potentially important source of N 2O via microbial denitrification that converts N to N2O and dinitrogen (N2). The fraction of denitrified N that escapes as N2O rather than N2 (i.e., the N2O yield) is an important determinant of how much N2O is produced by river networks, but little is known about the N2O yield in flowing waters. Here, we present the results of whole-stream 15N-tracer additions conducted in 72 headwater streams draining multiple land-use types across the United States. We found that stream denitrification produces N2O at rates that increase with stream water nitrate (NO3-) concentrations, but that <1% of denitrified N is converted to N2O. Unlike some previous studies, we found no relationship between the N2O yield and stream water NO3-. We suggest that increased stream NO3- loading stimulates denitrification and concomitant N2O production, but does not increase the N2O yield. In our study, most streams were sources of N2O to the atmosphere and the highest emission rates were observed in streams draining urban basins. Using a global river network model, we estimate that microbial N transformations (e.g., denitrification and nitrification) convert at least 0.68 Tg??y -1 of anthropogenic N inputs to N2O in river networks, equivalent to 10% of the global anthropogenic N2O emission rate. This estimate of stream and river N2O emissions is three times greater than estimated by the Intergovernmental Panel on Climate Change.

Pathogen and nutrient pulsing and attenuation in "accidental" urban wetland networks along the Salt River in Phoenix, AZ

NASA Astrophysics Data System (ADS)

Palta, M. M.; Grimm, N. B.

2013-12-01

Increases in available nutrients and bacteria in urban streams are at the forefront of research concerns within the ecological and medical communities, and both pollutants are expected to become more problematic under projected changes in climate. Season, discharge, instream conditions (oxygen, water velocity), and weather conditions (antecedent moisture) all may influence loading rates to and the retention capabilities of wetlands fed by urban runoff and storm flow. The aim of this research was to examine the effect of these variables on nutrient (nitrogen, phosphorus) and Escherichia coli (E. coli) loading and attenuation along flow paths in urban wetland networks along the Salt River in Phoenix, AZ. Samples were collected for one year along flowpaths through wetlands that formed below six perennially flowing outfalls. Collection took place monthly during baseflow (dry season) conditions, and before and immediately following storm events, in the summer monsoon and winter rainy seasons. Water quality was assessed at the following points: immediately downstream of the outfall, mid-wetland, and downstream of the wetland. For determination of E. coli counts, samples were plated on coliform-selective media (Chromocult) and incubated for 24 hours. Plates were then used to enumerate E. coli. For determination of nutrient concentrations, samples were filtered and frozen until they could be analyzed by ion chromatography and automated wet chemistry. During both summer and winter, total discharge into the wetlands increased during storm events. Concentrations of PO43+, NH4+, and E. coli were significantly higher following storm events than during baseflow conditions, and post-storm peaks in concentration ('pulses') were higher during the summer monsoon than in winter storms. Pulses of pollutants during storms were highest when preceded by hot, dry conditions. NO3- was high in both base and stormflow. E. coli counts and nutrient concentrations dropped along flowpaths through the wetlands, indicating high attenuation capability even during storms. Attenuation of nutrients during baseflow appeared to be a function of microbial processing, while during stormflow, when water retention time in the wetlands was reduced, attenuation was likely explained by other factors, such as sediment adsorption. Potential tradeoffs emerged between removal of NO3- (highest under low dissolved oxygen) and E. coli (highest under high dissolved oxygen) during baseflow. Climate change models project increases in severe droughts and extreme precipitation events for the southwestern United States, which can lead to more sewage leakages and increases in contaminated runoff from impervious surfaces in urban areas. Wetlands are constructed or restored to mitigate microbial contamination of wastewater. Our research indicates that even "accidental" urban wetlands can serve to reduce downstream transport of nutrients and pathogens in storm and wastewater. However, wetland restoration or design targeting increased water retention time may increase the capability of accidental wetlands in this urban desert river channel to remove nutrients and pathogens from stormwater.

Ionosphere-thermosphere energy budgets for the ICME storms of March 2013 and 2015 estimated with GITM and observational proxies

NASA Astrophysics Data System (ADS)

Verkhoglyadova, O. P.; Meng, X.; Mannucci, A. J.; Mlynczak, M. G.; Hunt, L. A.; Lu, G.

2017-09-01

The ionosphere-thermosphere (IT) energy partitioning for the interplanetary coronal mass ejection (ICME) storms of 16-19 March 2013 and 2015 is estimated with the Global Ionosphere-Thermosphere Model (GITM), empirical models and proxies derived from in situ measurements. We focus on auroral heating, Joule heating, and thermospheric cooling. Solar wind data, F10.7, OVATION Prime model and the Weimer 2005 model are used to drive GITM from above. Thermospheric nitric oxide and carbon dioxide cooling emission powers and fluxes are estimated from TIMED/SABER measurements. Assimilative mapping of ionospheric electrodynamics (AMIE) estimations of hemispheric power and Joule heating are presented, based on data from global magnetometers, the AMPERE magnetic field data, SSUSI auroral images, and the SuperDARN radar network. Modeled Joule heating and auroral heating of the IT system are mostly controlled by external driving in the March 2013 and 2015 storms, while NO cooling persists into the storm recovery phase. The total heating in the model is about 1000 GW to 3000 GW. Additionally, we intercompare contributions in selected energy channels for five coronal mass ejection-type storms modeled with GITM. Modeled auroral heating shows reasonable agreement with AMIE hemispheric power and is higher than other observational proxies. Joule heating and infrared cooling are likely underestimated in GITM. We discuss challenges and discrepancies in estimating and global modeling of the IT energy partitioning, especially Joule heating, during geomagnetic storms.

Radar Rainfall Statistics During PECAN

NASA Astrophysics Data System (ADS)

Romatschke, U.; Weckwerth, T.

2017-12-01

The Plains Elevated Convection At Night (PECAN) field campaign, based in Kansas, USA, took place from May to July 2015. It was designed to understand the causes and improve predictions of the central US nocturnal precipitation maximum. Over 100 instruments were utilized to sample the pre-convective and convective conditions within and around unorganized storms and Mesoscale Convective Systems (MCSs). We analyze quantitative precipitation estimates (QPEs) derived from a dense network of NEXRADs which, combined with S-Pol, cover an area extending from the eastern side of the Rocky Mountains over the Central Great Plains. As expected, precipitation maxima occurred during the afternoon and evening over the eastern Rocky Mountains and during the night over the plains. The precipitation over the mountains is almost exclusively associated with smaller scale storms which are triggered by solar heating over the elevated terrain. The mountain triggered storms quickly grow and merge to the size of MCSs and are then advected east over the plains. Storms are also initiated over the plains but at much lower frequency than over the mountains. The diurnal cycle of plain initiation is much less pronounced with a broad peak in the afternoon and evening but also significant convection initiation during the night. The nocturnal precipitation over the plains is primarily associated with the MCSs advected from the mountains which merge with the storms triggered over the plains. Some precipitation over the plains is generated by pristine storms triggered over the plains but their precipitation contribution is mostly secondary compared to the merged systems.

The North Alabama Lightning Mapping Array (LMA): A Network Overview

NASA Technical Reports Server (NTRS)

Blakeslee, R. J.; Bailey, J.; Buechler, D.; Goodman, S. J.; McCaul, E. W., Jr.; Hall, J.

2005-01-01

The North Alabama Lightning Mapping Array (LMA) is s a 3-D VHF regional lightning detection system that provides on-orbit algorithm validation and instrument performance assessments for the NASA Lightning Imaging Sensor, as well as information on storm kinematics and updraft evolution that offers the potential to improve severe storm warning lead time by up t o 50% and decrease te false alarm r a t e ( for non-tornado producing storms). In support of this latter function, the LMA serves as a principal component of a severe weather test bed to infuse new science and technology into the short-term forecasting of severe and hazardous weather, principally within nearby National Weather Service forecast offices. The LMA, which became operational i n November 2001, consists of VHF receivers deployed across northern Alabama and a base station located at the National Space Science and Technology Center (NSSTC), which is on t h e campus of the University of Alabama in Huntsville. The LMA system locates the sources of impulsive VHF radio signals s from lightning by accurately measuring the time that the signals aririve at the different receiving stations. Each station's records the magnitude and time of the peak lightning radiation signal in successive 80 ms intervals within a local unused television channel (channel 5, 76-82 MHz in our case ) . Typically hundreds of sources per flash can be reconstructed, which i n t u r n produces accurate 3-dimensional lightning image maps (nominally <50 m error within 150 la. range). The data are transmitted back t o a base station using 2.4 GHz wireless Ethernet data links and directional parabolic grid antennas. There are four repeaters in the network topology and the links have an effective data throughput rate ranging from 600 kbits s -1 t o 1.5 %its s -1. This presentation provides an overview of t h e North Alabama network, the data processing (both real-time and post processing) and network statistics.

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

USGS Publications Warehouse

Goode, Daniel J.; Koerkle, Edward H.; Hoffman, Scott A.; Regan, R. Steve; Hay, Lauren E.; Markstrom, Steven L.

2010-01-01

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.

Water resources planning for rivers draining into mobile bay

NASA Technical Reports Server (NTRS)

Ng, S.; April, G. C.

1976-01-01

A hydrodynamic model describing water movement and tidal elevation is formulated, computed, and used to provide basic data about water quality in natural systems. The hydrodynamic model is based on two-dimensional, unsteady flow equations. The water mass is considered to be reasonably mixed such that integration (averaging) in the depth direction is a valid restriction. Convective acceleration, the Coriolis force, wind and bottom interactions are included as contributing terms in the momentum equations. The solution of the equations is applied to Mobile Bay, and used to investigate the influence that river discharge rate, wind direction and speed, and tidal condition have on water circulation and holdup within the bay. Storm surge conditions, oil spill transport, artificial island construction, dredging, and areas subject to flooding are other topics which could be investigated using the mathematical modeling approach.

Coastal storm monitoring in Virginia

USGS Publications Warehouse

Wicklein, Shaun M.; Bennett, Mark

2014-01-01

Coastal communities in Virginia are prone to flooding, particularly during hurricanes, nor’easters, and other coastal low-pressure systems. These weather systems affect public safety, personal and public property, and valuable infrastructure, such as transportation, water and sewer, and electric-supply networks. Local emergency managers, utility operators, and the public are tasked with making difficult decisions regarding evacuations, road closures, and post-storm recovery efforts as a result of coastal flooding. In coastal Virginia these decisions often are made on the basis of anecdotal knowledge from past events or predictions based on data from monitoring sites located far away from the affected area that may not reflect local conditions. Preventing flood hazards, such as hurricane-induced storm surge, from becoming human disasters requires an understanding of the relative risks that flooding poses to specific communities. The risk to life and property can be very high if decisions about evacuations and road closures are made too late or not at all.

The spatial variations of lightning during small Florida thunderstorms

NASA Technical Reports Server (NTRS)

Oram, Timothy D.; Krider, E. Philip

1991-01-01

Networks of field mills (FM's) and lightning direction finders (LDF's) were used to locate lightning over the NASA KSC on three storm days. Over 90 percent of all cloud-to-ground (CG) flashes that were detected by the LDF's in the study area were also detected by the LDF's. About 17 percent of the FM CG events could be fitted to either a monopole or a dipole charge model. These projected FM charge locations are compared to LDF locations, i.e., the ground strike points. It was found that 95 percent of the LDF points are within 12 km of the FM charge, 75 percent are within 8 km, and 50 percent are within 4 km. For a storm on 22 Jul. 1988, there was a systematic 5.6 km shift between the FM charge centers and the LDF strike points that might have been caused by the meteorological structure of the storm.

Analysis of magnetic data of ground station network during strong magnetic storms

NASA Astrophysics Data System (ADS)

Mandrikova, Oksana; Solovev, Igor; Khomutov, Sergey; Baishev, Dmitry; Chandrasekhar, Phani

2017-10-01

The paper suggests a new technique for magnetic data analysis to detect and to estimate short-time anomalous increases in geomagnetic disturbance intensity. Based on the technique and applying the data of meridionally arranged stations in the north-east of Russia («Kotel'nyi» KTN, «Tixi» TIX, «Chokurdakh» CHD, «Zyryanka» ZYK, «Mys Shmidta» CPS, «Yakutsk» YAK, «Magadan» MGD, «Paratunka» PET, «Khabarovsk» KHB) and the near equatorial Indian stations ("Hyderabad" HYB and "Choutuppal" CPL), we analyzed the geomagnetic field variations during strong magnetic storms. This approach allowed us to detect simultaneously occurring local increases in geomagnetic activity observed a few hours before events and during the main phases of magnetic storms. The development of the method was supported by RSF Grant No.14-11-00194. Experimental investigations were supported by RFBR Grant No. 16-55-45007.

A twenty-first century California observing network for monitoring extreme weather events

USGS Publications Warehouse

White, A.B.; Anderson, M.L.; Dettinger, M.D.; Ralph, F.M.; Hinojosa, A.; Cayan, D.R.; Hartman, R.K.; Reynolds, D.W.; Johnson, L.E.; Schneider, T.L.; Cifelli, R.; Toth, Z.; Gutman, S.I.; King, C.W.; Gehrke, F.; Johnston, P.E.; Walls, C.; Mann, Dorte; Gottas, D.J.; Coleman, T.

2013-01-01

During Northern Hemisphere winters, the West Coast of North America is battered by extratropical storms. The impact of these storms is of paramount concern to California, where aging water supply and flood protection infrastructures are challenged by increased standards for urban flood protection, an unusually variable weather regime, and projections of climate change. Additionally, there are inherent conflicts between releasing water to provide flood protection and storing water to meet requirements for water supply, water quality, hydropower generation, water temperature and flow for at-risk species, and recreation. In order to improve reservoir management and meet the increasing demands on water, improved forecasts of precipitation, especially during extreme events, is required. Here we describe how California is addressing their most important and costliest environmental issue – water management – in part, by installing a state-of-the-art observing system to better track the area’s most severe wintertime storms.

Development of the Centralized Storm Information System (CSIS) for use in severe weather prediction

NASA Technical Reports Server (NTRS)

Mosher, F. R.

1984-01-01

The centralized storm information system is now capable of ingesting and remapping radar scope presentations on a satellite projection. This can be color enhanced and superposed on other data types. Presentations from more than one radar can be composited on a single image. As with most other data sources, a simple macro establishes the loops and scheduling of the radar ingestions as well as the autodialing. There are approximately 60 NWS network 10 cm radars that can be interrogated. NSSFC forecasters have found this data source to be extremely helpful in severe weather situations. The capability to access lightning frequency data stored in a National Weather Service computer was added. Plans call for an interface with the National Meteorological Center to receive and display prognostic fields from operational computer forecast models. Programs are to be developed to plot and display locations of reported severe local storm events.

Storm-based Cloud-to-Ground Lightning Probabilities and Warnings

NASA Astrophysics Data System (ADS)

Calhoun, K. M.; Meyer, T.; Kingfield, D.

2017-12-01

A new cloud-to-ground (CG) lightning probability algorithm has been developed using machine-learning methods. With storm-based inputs of Earth Networks' in-cloud lightning, Vaisala's CG lightning, multi-radar/multi-sensor (MRMS) radar derived products including the Maximum Expected Size of Hail (MESH) and Vertically Integrated Liquid (VIL), and near storm environmental data including lapse rate and CAPE, a random forest algorithm was trained to produce probabilities of CG lightning up to one-hour in advance. As part of the Prototype Probabilistic Hazard Information experiment in the Hazardous Weather Testbed in 2016 and 2017, National Weather Service forecasters were asked to use this CG lightning probability guidance to create rapidly updating probability grids and warnings for the threat of CG lightning for 0-60 minutes. The output from forecasters was shared with end-users, including emergency managers and broadcast meteorologists, as part of an integrated warning team.

Ground-based GNSS network and integrated water vapor mapping during the development of severe storms at the Cuyo region (Argentina)

NASA Astrophysics Data System (ADS)

Calori, A.; Santos, J. R.; Blanco, M.; Pessano, H.; Llamedo, P.; Alexander, P.; de la Torre, A.

2016-07-01

Mendoza is a province of Argentina located between 32° S and 34° S at the leeside of the Andes Foothills. Very intense thunderstorms form between October and March (southern hemisphere summer), which produce large hail and damage in crops and properties. Although some hypotheses and conceptual models were proposed in order to identify key possible mechanisms that contribute to trigger convection, they are still waiting for the validation process. As moisture is the main ingredient for storms formation, the identification of its geographical distribution could be used together with other synoptic and mesoscale forcing features to forecast intense convective events. A novel technique in estimating moisture concentration and its geographical distribution has been introduced in order to observe the influx and variability of humidity at this region, during a 45-day period in midsummer. In doing so, we resort to the information provided by the ground-basedGlobal Navigation Satellite System (GNSS) network. More than 300 active stations constitute the continuously operating GNSS network over Southern and Central America (SIRGAS-CON, Sistema de Referencia Geocéntrico para las Américas de Operación Continua). This network allows to retrieve integrated water vapor (IWV) content, mapping this variable by the use of a digital model of terrain. In the period and region under study, a prevailing influx of humidity from N and NE and a high correlation between the accumulation/depletion of humidity and the hail/no hail precipitation days is observed. We discuss in particular the development of five storms detected by the S-Band radar network belonging to the Province of Mendoza. Although the results strongly suggest that IWV maps are capable to represent the humidity dynamics in the considered region, it is still important to highlight that the calculated values for IWV are unrealistic at some locations as the consequence of deep atmospheric gradients. These biases may be explained by the fact that the GNSS observations are made over the whole horizon of each given site.

Disturbance dynamo effects over low-latitude F region: A study by network of VHF spaced receivers

NASA Astrophysics Data System (ADS)

Kakad, B.; Surve, G.; Tiwari, P.; Yadav, V.; Bhattacharyya, A.

2017-05-01

Generation of equatorial spread F (ESF) irregularities resulting from magnetic disturbance is known for past few decades. However, better prediction models for this phenomenon are still lacking. Magnetic storms also affects the F region plasma drifts. In this work we examined variability in (i) occurrence of such freshly generated ESF and (ii) low-latitude F region zonal plasma drifts over Indian longitude. For this purpose simultaneous observations of amplitude scintillations on 251 MHz signal, recorded by a network of spaced receivers located at low-latitude stations, are utilized. Observational stations are situated such that it longitudinally (latitudinally) covers an area of 5.6° (13°). Here effect of disturbance dynamo (DD) electric field at low-latitude F region and its variability are studied for three magnetic storms occurring in 2011. These magnetic storms are having nearly similar type characteristics except their start time. We find that as time difference (i.e., ΔT) between local sunset and start of magnetic activity decreases, the DD effects seen at low-latitude F region zonal irregularity drift around midnight becomes stronger. For a given magnetic storm the DD effect on F region zonal irregularity drifts is found to be only marginally stronger at dip equator in comparison to off-equatorial stations. Although effect of DD on F region zonal irregularity drifts are felt simultaneously, generation of fresh ESF is variable within a smaller longitudinal belt of 5.6°. It is attributed to the presence of LSWS at the bottomside of F region, as initiation of ESF is highly likely (unlikely) in the vicinity of crest (trough) of such LSWS.

Kinematic and Microphysical Control of Lightning Flash Rate over Northern Alabama

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Bain, Anthony L.; Matthee, Retha; Schultz, Christopher J.; Schultz, Elise V.; Deierling, Wiebke; Petersen, Walter A.

2015-01-01

The Deep Convective Clouds and Chemistry (DC3) experiment seeks to examine the relationship between deep convection and the production of nitrogen oxides (NO (sub x)) via lightning (LNO (sub x)). A critical step in estimating LNO (sub x) production in a cloud-resolving model (CRM) without explicit lightning is to estimate the flash rate from available model parameters that are statistically and physically correlated. As such, the objective of this study is to develop, improve and evaluate lightning flash rate parameterizations in a variety of meteorological environments and storm types using radar and lightning mapping array (LMA) observations taken over Northern Alabama from 2005-2012, including during DC3. UAH's Advanced Radar for Meteorological and Operational Research (ARMOR) and the Weather Surveillance Radar - 1988 Doppler (WSR 88D) located at Hytop (KHTX) comprises the dual-Doppler and polarimetric radar network, which has been in operation since 2004. The northern Alabama LMA (NA LMA) in conjunction with Vaisala's National Lightning Detection Network (NLDN) allow for a detailed depiction of total lightning during this period. This study will integrate ARMOR-KHTX dual Doppler/polarimetric radar and NA LMA lightning observations from past and ongoing studies, including the more recent DC3 results, over northern Alabama to form a large data set of 15-20 case days and over 20 individual storms, including both ordinary multicell and supercell convection. Several flash rate parameterizations will be developed and tested, including those based on 1) graupel/small hail volume; 2) graupel/small hail mass, and 3) convective updraft volume. Sensitivity of the flash rate parameterizations to storm intensity, storm morphology and environmental conditions will be explored.

Large Charge Moment Change Lightning in an Oklahoma Mesoscale Convective System

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Cummer, Steven; Petersen, Danyal; Flores-Rivera, Lizxandra; Lyons, Walt; MacGorman, Donald; Beasley, William

2014-01-01

On 31 May 2013, a line of severe thunderstorms developed during the local afternoon in central Oklahoma, USA. One of the supercells produced the El Reno tornado, which caused significant damage and killed several people. During the 2300 UTC hour (during the mature supercell stage and just after the tornado began), the storm produced several positive cloud-to-ground (+CG) lightning strokes that featured large (> 100 C km) impulse charge moment changes (iCMCs; charge moment during the first 2 ms after the return stroke). These discharges occurred mainly in convection, in contrast to the typical pattern of large-CMC and sprite-parent +CGs occurring mainly in stratiform precipitation regions. After this time, the line of thunderstorms evolved over several hours into a large mesoscale convective system (MCS). By the 0700 UTC hour on 1 June 2013, the large-CMC pattern had changed markedly. Large-CMC negative CGs, which were absent early in the storm's lifetime, occurred frequently within convection. Meanwhile, large-CMC +CGs had switched to occurring mainly within the broad stratiform region that had developed during the intervening period. The evolution of the large-CMC lightning in this case will be examined using a mix of national mosaics of radar reflectivity, the Oklahoma Lightning Mapping Array (OKLMA), the Charge Moment Change Network (CMCN), and the National Lightning Detection Network (NLDN). A major goal of this study is understanding how storm structure and evolution affected the production of large-CMC lightning. It is anticipated that this will lead to further insight into how and why storms produce the powerful lightning that commonly causes sprites in the upper atmosphere.

Deconstructing the Effects of Flow on DOC, Nitrate, and Major Ion Interactions Using a High-Frequency Aquatic Sensor Network

NASA Astrophysics Data System (ADS)

Koenig, L. E.; Shattuck, M. D.; Snyder, L. E.; Potter, J. D.; McDowell, W. H.

2017-12-01

Streams provide a physical linkage between land and downstream river networks, delivering solutes derived from multiple catchment sources. We analyzed high-frequency time series of stream solutes to characterize the timing and magnitude of major ion, nutrient, and organic matter transport over event, seasonal, and annual timescales as well as to assess whether nitrate (NO3-) and dissolved organic carbon (DOC) transport are coupled in catchments, which would be expected if they are subject to similar biogeochemical controls throughout the watershed. Our data set includes in situ observations of NO3-, fluorescent dissolved organic matter (DOC proxy), and specific conductance spanning 2-4 years in 10 streams and rivers across New Hampshire, including observations of nearly 700 individual hydrologic events. We found a positive response of NO3- and DOC to flow in forested streams, but watershed development led to a negative relationship between NO3- and discharge, and thus a decoupling of the overall NO3- and DOC responses to flow. On event and seasonal timescales, NO3- and DOC consistently displayed different behaviors. For example, in several streams, FDOM yield was greatest during summer storms while NO3- yield was greatest during winter storms. Most streams had generalizable storm NO3- and DOC responses, but differences in the timing of NO3- and DOC transport suggest different catchment sources. Further, certain events, including rain-on-snow and summer storms following dry antecedent conditions, yielded disproportionate NO3- responses. High-frequency data allow for increased understanding of the processes controlling solute variability and will help reveal their responses to changing climatic regimes.

Large Charge Moment Change Lightning in an Oklahoma Mesoscale Convective System

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Cummer, Steven; Beasley, William; Flores-Rivera, Lizxandra; Lyons, Walt; MacGorman, Donald

2014-01-01

On 31 May 2013, a line of severe thunderstorms developed during the local afternoon in central Oklahoma, USA. One of the supercells produced the El Reno tornado, which caused significant damage and killed several people. During the 2300 UTC hour (during the mature supercell stage and just after the tornado began), the storm produced several positive cloud-to-ground (+CG) lightning strokes that featured large (> 75 C km) impulse charge moment changes (iCMCs - charge moment during the first 2 ms after the return stroke). These discharges occurred mainly in convection, in contrast to the typical pattern of large-CMC and sprite-parent +CGs occurring mainly in stratiform precipitation regions. After this time, the line of thunderstorms evolved over several hours into a large mesoscale convective system (MCS). By the 0700 UTC hour on 1 June 2013, the large- CMC pattern had changed markedly. Large-CMC negative CGs, which were absent early in the storm's lifetime, occurred frequently within convection. Meanwhile, large- CMC +CGs had switched to occurring mainly within the broad stratiform region that had developed during the intervening period. The evolution of the large-CMC lightning in this case will be examined using a mix of polarimetric data from individual radars, national mosaics of radar reflectivity, the Oklahoma Lightning Mapping Array (OKLMA), the Charge Moment Change Network (CMCN), and the National Lightning Detection Network (NLDN). A major goal of this study is understanding how storm structure and evolution affected the production of large-CMC lightning. It is anticipated that this will lead to further insight into how and why storms produce the powerful lightning that commonly causes sprites in the upper atmosphere.

Applying four principles of headwater system aquatic biology to forest management

Treesearch

Robert J. Danehy; Sherri L. Johnson

2013-01-01

Headwater systems, including the channel and the adjacent riparian forest, are a dominant landscape feature in forested watersheds, draining most of the watershed area, and comprising the majority of channel length in drainage networks. Being at the upper extent of watersheds, these systems are smaller and steeper than large streams, and create microhabitats that...

75TH Field Artillery Brigade Ammunition Resupply During Operation Desert Storm

DTIC Science & Technology

1992-06-05

units. Ammunition delivery competes for these assets but usually has a significantly higher priority than general supplies. Road or rail networks ...Eckelston, Tom MAJ. Interview with author. Tape recording. Ft. Leavenworth, Kansas, 10 January 1992. Force devopment test and experimentation

Space weather modeling using artificial neural network. (Slovak Title: Modelovanie kozmického počasia umelou neurónovou sietou)

NASA Astrophysics Data System (ADS)

Valach, F.; Revallo, M.; Hejda, P.; Bochníček, J.

2010-12-01

Our modern society with its advanced technology is becoming increasingly vulnerable to the Earth's system disorders originating in explosive processes on the Sun. Coronal mass ejections (CMEs) blasted into interplanetary space as gigantic clouds of ionized gas can hit Earth within a few hours or days and cause, among other effects, geomagnetic storms - perhaps the best known manifestation of solar wind interaction with Earth's magnetosphere. Solar energetic particles (SEP), accelerated to near relativistic energy during large solar storms, arrive at the Earth's orbit even in few minutes and pose serious risk to astronauts traveling through the interplanetary space. These and many other threats are the reason why experts pay increasing attention to space weather and its predictability. For research on space weather, it is typically necessary to examine a large number of parameters which are interrelated in a complex non-linear way. One way to cope with such a task is to use an artificial neural network for space weather modeling, a tool originally developed for artificial intelligence. In our contribution, we focus on practical aspects of the neural networks application to modeling and forecasting selected space weather parameters.

Modeling of Current Consumption in 802.15.4/ZigBee Sensor Motes

PubMed Central

Casilari, Eduardo; Cano-García, Jose M.; Campos-Garrido, Gonzalo

2010-01-01

Battery consumption is a key aspect in the performance of wireless sensor networks. One of the most promising technologies for this type of networks is 802.15.4/ZigBee. This paper presents an empirical characterization of battery consumption in commercial 802.15.4/ZigBee motes. This characterization is based on the measurement of the current that is drained from the power source under different 802.15.4 communication operations. The measurements permit the definition of an analytical model to predict the maximum, minimum and mean expected battery lifetime of a sensor networking application as a function of the sensor duty cycle and the size of the sensed data. PMID:22219671

Modeling of current consumption in 802.15.4/ZigBee sensor motes.

PubMed

Casilari, Eduardo; Cano-García, Jose M; Campos-Garrido, Gonzalo

2010-01-01

Battery consumption is a key aspect in the performance of wireless sensor networks. One of the most promising technologies for this type of networks is 802.15.4/ZigBee. This paper presents an empirical characterization of battery consumption in commercial 802.15.4/ZigBee motes. This characterization is based on the measurement of the current that is drained from the power source under different 802.15.4 communication operations. The measurements permit the definition of an analytical model to predict the maximum, minimum and mean expected battery lifetime of a sensor networking application as a function of the sensor duty cycle and the size of the sensed data.

Doppler Radar and Cloud-to-Ground Lightning Observations of a Severe Outbreak of Tropical Cyclone Tornadoes

NASA Technical Reports Server (NTRS)

McCaul, Eugene W., Jr.; Buechler, Dennis; Cammarata, Michael; Arnold, James E. (Technical Monitor)

2002-01-01

Data from a single WSR-88D Doppler radar and the National Lightning Detection Network are used to examine the characteristics of the convective storms that produced a severe tornado outbreak within Tropical Storm Beryl's remnants on 16 August 1994. Comparison of the radar data with reports of tornadoes suggests that only 12 cells produced the 29 tornadoes that were documented in Georgia and the Carolinas on that date. Six of these cells spawned multiple tornadoes, and the radar data confirm the presence of miniature supercells. One of the cells was identifiable on radar for 11 hours, spawning tornadoes over a time period spanning approximately 6.5 hours. Time-height analyses of the three strongest supercells are presented in order to document storm kinematic structure and evolution. These Beryl mini-supercells were comparable in radar-observed intensity but much more persistent than other tropical cyclone-spawned tornadic cells documented thus far with Doppler radars. Cloud-to-ground lightning data are also examined for all the tornadic cells in this severe swarm-type tornado outbreak. These data show many of the characteristics of previously reported heavy-precipitation supercells. Lightning rates were weak to moderate, even in the more intense supercells, and in all the storms the lightning flashes were almost entirely negative in polarity. No lightning at all was detected in some of the single-tornado storms. In the stronger cells, there is some evidence that lightning rates can decrease during tornadogenesis, as has been documented before in some midlatitude tornadic storms. A number of the storms spawned tornadoes just after producing their final cloud-to-ground lightning flashes. These findings suggest possible benefits from implementation of observing systems capable of monitoring intracloud as well as cloud-to-ground lightning activity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Renno, Nilton O.; Ruf, Christopher S., E-mail: renno@alum.mit.edu

Ruf et al. used the Deep Space Network (DSN) to search for the emission of non-thermal radiation by martian dust storms, theoretically predicted by Renno et al. They detected the emission of non-thermal radiation that they were searching for, but were surprised that it contained spectral peaks suggesting modulation at various frequencies and their harmonics. Ruf et al. hypothesized that the emission of non-thermal radiation was caused by electric discharges in a deep convective dust storm, modulated by Schumann resonances (SRs). Anderson et al. used the Allen Telescope Array (ATA) to search for similar emissions. They stated that they foundmore » only radio frequency interference (RFI) during their search for non-thermal emission by martian dust storms and implicitly suggested that the signal detected by Ruf et al. was also RFI. However, their search was not conducted during the dust storm season when deep convective storms are most likely to occur. Here, we show that the ubiquitous dust devils and small-scale dust storms that were instead likely present during their observations are too shallow to excite SRs and produce the signals detected by Ruf et al. We also show that the spectral and temporal behavior of the signals detected by Anderson et al. corroborates the idea that they originated from man-made pulse-modulated telecommunication signals rather than martian electric discharges. In contrast, an identical presentation of the signals detected by Ruf et al. demonstrates that they do not resemble man-made signals. The presentation indicates that the DSN signals were consistent with modulation by martian SRs, as originally hypothesized by Ruf et al. We propose that a more comprehensive search for electrostatic discharges be conducted with either the ATA or DSN during a future martian dust storm season to test the hypothesis proposed by Ruf et al.« less

Species Richness and Functional Trait Diversity for Plants in Southern California's Green Infrastructure along a Climate Gradient

NASA Astrophysics Data System (ADS)

Rochford, M. E.; Ibsen, P.; Jenerette, D.

2016-12-01

Green infrastructure (GI) is greenery planted to absorb rainwater into the earth as an alternative to grey infrastructure, like storm drains. Not only does GI prevent flooding, but it also performs a number of ecosystem services, including increasing biodiversity, because it allows water to cycle through the environment naturally. Increased biodiversity in plant communities is said to help purify the air and improve the health and resilience of the plants themselves. I want to investigate these claims about GI's benefits by studying types of GI with slightly different functions. This will answer the questions 1) Are different types of green infrastructure's plant communities equally biodiverse in terms of functional trait diversity and species richness? 2) How does functional trait diversity and species richness differ along a temperature gradient in Southern California? To compare biodiversity, I must survey four different types of GI, urban parks, riparian zones, detention basins, and bioswales, in three cities in distinct climate regions. Detention basins are reservoirs lined with vegetation that collect water until it is absorbed into the soil. Bioswales are vegetated gutters that filter out pollutants in storm water. Unlike retention basins, they also add aesthetic value to an area. Even though parks are mainly for recreation and beatification rather than storm water management, they have plenty of permeable surface to absorb storm water. The types of GI that have high levels of interaction with humans should also have higher levels of maintenance. The results should follow the homogenization hypothesis and demonstrate that, regardless of climate, species richness should not differ much between highly maintained areas, like parks, in different cities. Otherwise, in GI that is not as manicured, species richness should be significantly different between cities and the different types of GI. Because types of GI selected vary in expected levels of human interaction, their functional trait composition should also differ. Functional trait diversity should not change much between the same types of GI in different regions because they experience similar levels of interaction with humans. This experiment will give an indication of how much temperature and human interaction influence biodiversity in GI.

Reducing sediment inputs to Scottish streams: a review of the efficacy of soil conservation practices in upland forestry.

PubMed

Carling, P A; Irvine, B J; Hill, A; Wood, M

2001-01-29

The historical process by which a soil conservation strategy has evolved within the UK forestry industry is briefly reviewed. Particular attention is given to the development of practical and effective guidelines to prevent both soil damage and sediment entering water courses. It is concluded that the 'Forest and Water Guidelines', together with other forest industry manuals, largely provide adequate protection for aquatic habitats from pre-afforestation cultivation and from harvesting activities. The problem of soil erosion owing to ploughing of open furrows has largely been obviated by improved drainage network design coupled with the use of vegetated buffer strips and sediment catchpits. Alternative site preparation techniques, such as 'moling' or 'dolloping' of afforestation sites, are now preferred. However, the effects on slope hydrology and the improved soil conservation associated with these methods require quantifying. Additional understanding of effective buffer strip function, for example, on a variety of slope angles, soil types and vegetation associations would be beneficial. The design of forest roads and the associated network of drains, culverts and sediment catchpits is addressed in forestry guidelines. Future potential in this area may involve the use of Geographical Information Systems in the effective design of road networks which minimise adverse effects on slope hydrology. Similarly computer simulation of flow routing might aid in the design of road drain networks. At the more local scale there remains scope for further research aimed at minimising soil disturbance by machinery. Consideration should also be given to the long-term sustainability of the soil structure through second and subsequent crop rotations.

Natural Flood Management in context: evaluating and enhancing the impact.

NASA Astrophysics Data System (ADS)

Metcalfe, Peter; Beven, Keith; Hankin, Barry; Lamb, Rob

2016-04-01

The series of flood events in the UK throughout December 2015 have led to calls for a reappraisal of the country's approach to flood management. In parts of Cumbria so-called "1 in 100" year floods have occurred three times in the last ten years, leading to significant infrastructure damage. Hard-engineered defences upgraded to cope with an anticipated 20% increase in peak flows and these 1% AEP events have been overwhelmed. It has become more widely acknowledged that unsympathetic agricultural and upland management practices, mainly since the Second World War, have led to a significant loss of storage in mid and upper catchments and their consequent ability to retain and slow storm run-off. Natural Flood Management (NFM) is a nature-based solution to restoring this storage and flood peak attenuation through a network of small-scale features exploiting natural topography and materials. Combined with other "soft" interventions such as restoring flood plain roughness and tree-planting, NFM offers the attractive prospect of an intervention that can target both the ecological and chemical objectives of the Water Framework Directive and the resilience demanded by the Floods Directive. We developed a simple computerised physical routing model that can account for the presence of in-channel and offline features such as would be found in a NFM scheme. These will add storage to the channel and floodplain and throttle the downstream discharge at storm flows. The model was applied to the heavily-modified channel network of an agricultural catchment in North Yorkshire using the run-off simulated for two storm events that caused flooding downstream in the autumn of 2012. Using up to 60 online features we demonstrated some gains in channel storage and a small impact on the flood hydrograph which would, however, have been insufficient to prevent the downstream floods in either of the storms. Complementary research at JBA has applied their hydrodynamic model JFLOW+ to identify areas of the catchment that will naturally retain storm run-off and quantified the effects of removing this storage on the run-off. It is suggested that enhancing the storage capacity of these areas may be a low impact approach in keeping with the ethos of NFM that has a significant, and quantifiable impact, on storm flows.

Preliminary Analysis of IR Cloudtop Temperatures of Sprite Producing Storms over Argentina Observed from Brazil, and Comparison with US Case Study

NASA Astrophysics Data System (ADS)

Sao Sabbas, F. T.; Pautet, P.; Taylor, M. J.; Pinto, O.; Thomas, J.; Solorzano, N.; Holzworth, R.; Bailey, M.; Schuch, N.; Michels, M.

2006-12-01

We will present the preliminary results of the cloudtop temperature characteristics of two very active sprite- producing Mesoscale Convective System (MCS) which occurred over Argentina in the evening of February 22, and March 04, 2006. These were prolific storms, e.g. the first one produced more than 400 TLEs, including sprites, halos and possibly elves. The events were observed from the INPE Observatorio Espacial Sul-OES (Southern Space Observatory), located at the center of Rio Grande do Sul State, the most Southern State of Brazil. Except for the lack of triangulated locations for the sprites and halos recorded, the methodology used for this study is the same as for the paper Sao Sabbas and Sentman [2003], where a sprite producing storm over the central U.S. was observed during the night of July 22, 1996. We analyzed the IR satellite data provided by GOES-12 and the lightning information from the Brazilian Lightning Detection Network in combination with data from the World Wide Lightning Location Network WWLLN. We will also show a comparison between the obtained results and the results presented at the Sao Sabbas and Sentman [2003] paper. Sao Sabbas, F.T. and D. D. Sentman, Dynamical Relationship of IR Cloudtop Temperatures With Occurrence Rates of Cloud-to-Ground Lightning and Sprites, Geophys. Res. Lett., 30 (5), 40-1-40-4, 2003.

A New U.S. West Coast Network of Atmospheric River Observatories

NASA Astrophysics Data System (ADS)

White, A. B.; Wilczak, J. M.; Ayers, T. E.; King, C. W.; Jordan, J. R.; Shaw, W. J.; Flaherty, J. E.; Morris, V. R.

2015-12-01

The West Coast of North America is the gateway to winter storms forming over the Pacific Ocean that deliver most of the precipitation and water supply to the region. Satellites are capable of detecting the concentrated water vapor in these storms (a.k.a. atmospheric rivers) over the oceans, but because of the complex emissivity of land surfaces, fail to do so over land. In addition, these storms often are accompanied by a baroclinically induced low-level jet that drives the moisture up the windward slopes of coastal and inland mountain ranges and produces orographically enhanced precipitation. To date, satellites cannot resolve this important feature. NOAA's Hydrometeorology Testbed (HMT; hmt.noaa.gov) has developed the concept of an atmospheric river observatory (ARO); a collection of ground-based instruments capable of detecting and monitoring the water vapor transport in the low-level jet region. With funding provided by the California Department of Water Resources and U.S. Department of Energy, HMT has installed a picket fence of AROs along the U.S. West Coast. In addition, HMT has developed an award-winning water vapor flux tool that takes advantage of the data collected by the AROs to provide situational awareness and decision support for end users. This tool recently has been updated to include operational weather prediction output. The ARO network and water vapor flux tool will be described in this presentation.

Effectiveness of a stormwater collection and detention system for reducing constituent loads from bridge runoff in Pinellas County, Florida

USGS Publications Warehouse

Stoker, Y.E.

1996-01-01

The quantity and quality of stormwater runoff from the Bayside Bridge were evaluated to determine the effectiveness of the stormwater collection and detention pond system of the bridge in reducing constituent loads to Old Tampa Bay. Water-quality samples of stormwater runoff from the bridge and outflow from the detention pond were collected during and after selected storms. These samples were used to compute loads for selected constituents. Stormwater on the Bayside Bridge drained rapidly during rain events. The volume of stormwater runoff from 24 storms measured during the study ranged from 4,086 to 103,705 cubic feet. Storms were most frequent during July through September and were least frequent from February through May. Concentrations of most constituents in stormwater runoff before the bridge opened to traffic were less than or equal to concentrations measured after the bridge was opened to traffic. However, concentrations of arsenic in the outflow from the detention pond generally were greater before the bridge opened than concentrations after, and concentrations of orthophosphorus in the stormwater runoff and outflow from the pond were greater before the bridge opened than during over half the sampled storms after the bridge opened. Concentrations of most constituents measured in stormwater runoff from the bridge were greatest at the beginning of the storm and decreased as the storm continued. Variations in suspended solids, nutrients, and trace element concentrations were not always concurrent with each other. The source of the measured constituent (rainfall or road debris) and the phase of the constituent (suspended or dissolved) probably affected the timing of concentration changes. The quality of stormwater runoff from the Bayside Bridge varied with total runoff volume, with the length of the dry period before the storm, and with season. Average concentrations of suspended solids, ammonia plus organic nitrogen, nitrite plus nitrate nitrogen, orthophosphorus, phosphorus, total organic carbon, aluminum, arsenic, copper, and zinc in stormwater runoff generally were inversely related to runoff volume. The quality of outflow from the detention pond also varied during a storm event and with season. Maximum concentrations generally occurred near the beginning of a storm, and decreased as the storm continued. Maximum concentrations of many constituents occurred in June and July 1995. During the summer months, pH exceeded 9.0 while inorganic nitrogen concentrations were very low. These high pH values and low inorganic nitrogen concentrations are most likely associated with photosynthesis by algae or aquatic plants in the pond. Concentrations of nitrogen, phosphorus, and nickel in stormwater runoff were correlated with total organic carbon concentrations. Concentrations of chromium, copper, iron, nickel, lead, and zinc in stormwater runoff were correlated with aluminum concentrations. The source of these metals is probably the bridge materials and metallic debris from vehicles. The northern detention pond system of the Bayside Bridge effectively reduced concentrations of suspended solids, ammonia nitrogen, nitrite plus nitrate nitrogen, phosphorus, aluminum, cadmium, chromium, copper, iron, lead, nickel, and zinc in stormwater runoff before water discharged from the pond. However, concentrations of ammonia plus organic nitrogen, organic carbon, arsenic, and values for alkalinity, pH, and specific conductance generally were greater in outflow from the pond than in stormwater runoff from the bridge. Stormwater runoff and pond outflow for three storm events were evaluated to determine the effectiveness of the detention pond system in removing selected constituents from the stormwater runoff. Most constituents and constituent loads were reduced in the outflow from the pond. Suspended solids loads were reduced about 30 to 45 percent, inorganic nitrogen loads were reduced by about 60 to 90 percent, and loads of most trace elements

An automated and integrated framework for dust storm detection based on ogc web processing services

NASA Astrophysics Data System (ADS)

Xiao, F.; Shea, G. Y. K.; Wong, M. S.; Campbell, J.

2014-11-01

Dust storms are known to have adverse effects on public health. Atmospheric dust loading is also one of the major uncertainties in global climatic modelling as it is known to have a significant impact on the radiation budget and atmospheric stability. The complexity of building scientific dust storm models is coupled with the scientific computation advancement, ongoing computing platform development, and the development of heterogeneous Earth Observation (EO) networks. It is a challenging task to develop an integrated and automated scheme for dust storm detection that combines Geo-Processing frameworks, scientific models and EO data together to enable the dust storm detection and tracking processes in a dynamic and timely manner. This study develops an automated and integrated framework for dust storm detection and tracking based on the Web Processing Services (WPS) initiated by Open Geospatial Consortium (OGC). The presented WPS framework consists of EO data retrieval components, dust storm detecting and tracking component, and service chain orchestration engine. The EO data processing component is implemented based on OPeNDAP standard. The dust storm detecting and tracking component combines three earth scientific models, which are SBDART model (for computing aerosol optical depth (AOT) of dust particles), WRF model (for simulating meteorological parameters) and HYSPLIT model (for simulating the dust storm transport processes). The service chain orchestration engine is implemented based on Business Process Execution Language for Web Service (BPEL4WS) using open-source software. The output results, including horizontal and vertical AOT distribution of dust particles as well as their transport paths, were represented using KML/XML and displayed in Google Earth. A serious dust storm, which occurred over East Asia from 26 to 28 Apr 2012, is used to test the applicability of the proposed WPS framework. Our aim here is to solve a specific instance of a complex EO data and scientific model integration problem by using a framework and scientific workflow approach together. The experimental result shows that this newly automated and integrated framework can be used to give advance near real-time warning of dust storms, for both environmental authorities and public. The methods presented in this paper might be also generalized to other types of Earth system models, leading to improved ease of use and flexibility.

CAWSES Related Projects in Japan : Grant-in-Aid for Creative Scientific Research ügBasic Study of Space Weather Predictionüh and CHAIN (Continuous H Alpha Imaging Network)

NASA Astrophysics Data System (ADS)

Shibata, K.; Kurokawa, H.

The Grant-in-Aid for Creative Scientific Research of the Ministry of Education Science Sports Technology and Culture of Japan The Basic Study of Space Weather Prediction PI K Shibata Kyoto Univ has started in 2005 as 5 years projects with total budget 446Myen The purpose of this project is to develop a physical model of solar-terrestrial phenomena and space storms as a basis of space weather prediction by resolving fundamental physics of key phenomena from solar flares and coronal mass ejections to magnetospheric storms under international cooperation program CAWSES Climate and Weather of the Sun-Earth System Continuous H Alpha Imaging Network CHAIN Project led by H Kurokawa is a key project in this space weather study enabling continuous H alpha full Sun observations by connecting many solar telescopes in many countries through internet which provides the basis of the study of space weather prediction

Development of flood probability charts for urban drainage network in coastal areas through a simplified joint assessment approach

NASA Astrophysics Data System (ADS)

Archetti, R.; Bolognesi, A.; Casadio, A.; Maglionico, M.

2011-04-01

The operating conditions of urban drainage networks during storm events certainly depend on the hydraulic conveying capacity of conduits but also on downstream boundary conditions. This is particularly true in costal areas where the level of the receiving water body is directly or indirectly affected by tidal or wave effects. In such cases, not just different rainfall conditions (varying intensity and duration), but also different sea-levels and their effects on the network operation should be considered. This paper aims to study the behaviour of a seaside town storm sewer network, estimating the threshold condition for flooding and proposing a simplified method to assess the urban flooding severity as a function of either climate variables. The case study is a portion of the drainage system of Rimini (Italy), implemented and numerically modelled by means of InfoWorks CS code. The hydraulic simulation of the sewerage system has therefore allowed to identify the percentage of nodes of the drainage system where flooding is expected to occur. Combining these percentages with both climate variables values has lead to the definition charts representing the combined degree of risk "sea-rainfall" for the drainage system under investigation. A final comparison between such charts and the results obtained from a one-year sea-rainfall time series has confirmed the reliability of the analysis.

Development of flood probability charts for urban drainage network in coastal areas through a simplified joint assessment approach

NASA Astrophysics Data System (ADS)

Archetti, R.; Bolognesi, A.; Casadio, A.; Maglionico, M.

2011-10-01

The operating conditions of urban drainage networks during storm events depend on the hydraulic conveying capacity of conduits and also on downstream boundary conditions. This is particularly true in coastal areas where the level of the receiving water body is directly or indirectly affected by tidal or wave effects. In such cases, not just different rainfall conditions (varying intensity and duration), but also different sea-levels and their effects on the network operation should be considered. This paper aims to study the behaviour of a seaside town storm sewer network, estimating the threshold condition for flooding and proposing a simplified method to assess the urban flooding severity as a function of climate variables. The case study is a portion of the drainage system of Rimini (Italy), implemented and numerically modelled by means of InfoWorks CS code. The hydraulic simulation of the sewerage system identified the percentage of nodes of the drainage system where flooding is expected to occur. Combining these percentages with both climate variables' values has lead to the definition of charts representing the combined degree of risk "rainfall-sea level" for the drainage system under investigation. A final comparison between such charts and the results obtained from a one-year rainfall-sea level time series has demonstrated the reliability of the analysis.

Relation of water quality to land use in the drainage basins of four tributaries to the Toms River, New Jersey, 1994-95

USGS Publications Warehouse

Hunchak-Kariouk, Kathryn

1999-01-01

The influence of land use on the water quality of four tributaries to the Toms River, which drains nearly one-half of the Barnegat Bay wateshed, was studied during the initial phase of a multiyear investigation. Water samples were collected from and streamflows were measured in Long Swamp Creek, Wrangel Brook, Davenport Branch, and Jakes Creek during periods of base flow and stormflow in the growing and nongrowing seasons during May 1994 to October 1995. The drainage areas upstream from the seven measurement sites were characterized as highly developed, moderately developed, slightly developed, or undeveloped. Concentrations were determined and area-normalized instantaneous loads (yields) were estimated for total nitrogen, ammonia, nitrate, organic nitrogen, hydrolyzable phosphorus plus orthosphosphorus, orthophosphorus, total suspended solids, and fecal-coliform bacteria in the water samples. Specific conductance, pH, temperature, and dissolved oxygen were measured. Yields of total nitrogen, nitrate, and organic nitrogen at sites on Wrangel Brook, which drains moderately developed areas, were either larger than or similar to yields at the site on Long Swamp Creek, which drains a highly developed area. The magnitude of these yields probably was not related directly to the intensity of land development, but more likely was influenced by the type of development, the amount of base flow, and historical land use in the basin. The large concentrations of total nitrogen and nitrate in base flow in Wrangel Brook could have resulted from fertilizers that were applied to high-maintenance lawns and from agricultural runoff that has remained in the ground water since the 1950's and eventually was discharged to streams. Yields of ammonia appear to be partly related to the intensity of land development and storm runoff. Yields of ammonia at the site on Long Swamp Creek (a highly developed area) were either larger than or similar to yields at sites on Wrangel Brook (moderately developed areas). Yields were smallest at the site on Davenport Branch, which drains a slightly developed area. Yields of hydrolyzable phosphorus plus orthophosphorus and yields of orthophosphorus appear to be related to the intensity of development. Concentrations of hydrolyzable phosphorus plus orthophosphorus were greater in Long Swamp Creek (highly developed areas) than in Wrangel Brook (moderately developed areas). Concentrations of orthophosphorus were largest in Wrangel Brook (moderately developed) and Long Swamp Creek (highly developed). Total suspended solids and bacteria were somewhat related to intensity of development. Yields of total suspended solids were greater at sites downstream from highly and moderately developed areas than from slightly developed areas. Yields of bacteria were strongly related to streamflow and season. Specific conductance appears to be related to streamflow. pH probably was related to intensity of land development; pH was greater (more basic) in streams draining highly developed areas than in those draining other areas. Concentrations of dissolved oxygen were affected more by water temperature than by intensity of development or streamflow.

Sampling frequency for water quality variables in streams: Systems analysis to quantify minimum monitoring rates.

PubMed

Chappell, Nick A; Jones, Timothy D; Tych, Wlodek

2017-10-15

Insufficient temporal monitoring of water quality in streams or engineered drains alters the apparent shape of storm chemographs, resulting in shifted model parameterisations and changed interpretations of solute sources that have produced episodes of poor water quality. This so-called 'aliasing' phenomenon is poorly recognised in water research. Using advances in in-situ sensor technology it is now possible to monitor sufficiently frequently to avoid the onset of aliasing. A systems modelling procedure is presented allowing objective identification of sampling rates needed to avoid aliasing within strongly rainfall-driven chemical dynamics. In this study aliasing of storm chemograph shapes was quantified by changes in the time constant parameter (TC) of transfer functions. As a proportion of the original TC, the onset of aliasing varied between watersheds, ranging from 3.9-7.7 to 54-79 %TC (or 110-160 to 300-600 min). However, a minimum monitoring rate could be identified for all datasets if the modelling results were presented in the form of a new statistic, ΔTC. For the eight H + , DOC and NO 3 -N datasets examined from a range of watershed settings, an empirically-derived threshold of 1.3(ΔTC) could be used to quantify minimum monitoring rates within sampling protocols to avoid artefacts in subsequent data analysis. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Urbanisation impacts on storm runoff along a rural-urban gradient

NASA Astrophysics Data System (ADS)

Miller, James David; Hess, Tim

2017-09-01

Urbanisation alters the hydrological response of catchments to storm events and spatial measures of urban extent and imperviousness are routinely used in hydrological modelling and attribution of runoff response to land use changes. This study evaluates whether a measure of catchment urban extent can account for differences in runoff generation from storm events along an rural-urban gradient. We employed a high-resolution monitoring network across 8 catchments in the south of the UK - ranging from predominantly rural to heavily urbanised - over a four year period, and from this selected 336 storm events. Hydrological response was compared using volume- and scaled time-based hydrograph metrics within a statistical framework that considered the effect of antecedent soil moisture. Clear differences were found between rural and urban catchments, however above a certain threshold of urban extent runoff volume was relatively unaffected by changes and runoff response times were highly variable between catchments due to additional hydraulic controls. Results indicate a spatial measure of urbanisation can generally explain differences in the hydrological response between rural and urban catchments but is insufficient to explain differences between urban catchments along an urban gradient. Antecedent soil moisture alters the volume and timing of runoff generated in catchments with large rural areas, but was not found to affect the runoff response where developed areas are much greater. The results of this study suggest some generalised relationships between urbanisation and storm runoff are not represented in observed storm events and point to limitations in using a simplified representations of the urban environment for attribution of storm runoff in small urban catchments. The study points to the need for enhanced hydrologically relevant catchment descriptors specific to small urban catchments and more focused research on the role of urban soils and soil moisture in storm runoff generation in mixed land-use catchments.

Bayesian network modeling applied to coastal geomorphology: lessons learned from a decade of experimentation and application

NASA Astrophysics Data System (ADS)

Plant, N. G.; Thieler, E. R.; Gutierrez, B.; Lentz, E. E.; Zeigler, S. L.; Van Dongeren, A.; Fienen, M. N.

2016-12-01

We evaluate the strengths and weaknesses of Bayesian networks that have been used to address scientific and decision-support questions related to coastal geomorphology. We will provide an overview of coastal geomorphology research that has used Bayesian networks and describe what this approach can do and when it works (or fails to work). Over the past decade, Bayesian networks have been formulated to analyze the multi-variate structure and evolution of coastal morphology and associated human and ecological impacts. The approach relates observable system variables to each other by estimating discrete correlations. The resulting Bayesian-networks make predictions that propagate errors, conduct inference via Bayes rule, or both. In scientific applications, the model results are useful for hypothesis testing, using confidence estimates to gage the strength of tests while applications to coastal resource management are aimed at decision-support, where the probabilities of desired ecosystems outcomes are evaluated. The range of Bayesian-network applications to coastal morphology includes emulation of high-resolution wave transformation models to make oceanographic predictions, morphologic response to storms and/or sea-level rise, groundwater response to sea-level rise and morphologic variability, habitat suitability for endangered species, and assessment of monetary or human-life risk associated with storms. All of these examples are based on vast observational data sets, numerical model output, or both. We will discuss the progression of our experiments, which has included testing whether the Bayesian-network approach can be implemented and is appropriate for addressing basic and applied scientific problems and evaluating the hindcast and forecast skill of these implementations. We will present and discuss calibration/validation tests that are used to assess the robustness of Bayesian-network models and we will compare these results to tests of other models. This will demonstrate how Bayesian networks are used to extract new insights about coastal morphologic behavior, assess impacts to societal and ecological systems, and communicate probabilistic predictions to decision makers.

Characterising Event-Based DOM Inputs to an Urban Watershed

NASA Astrophysics Data System (ADS)

Croghan, D.; Bradley, C.; Hannah, D. M.; Van Loon, A.; Sadler, J. P.

2017-12-01

Dissolved Organic Matter (DOM) composition in urban streams is dominated by terrestrial inputs after rainfall events. Urban streams have particularly strong terrestrial-riverine connections due to direct input from terrestrial drainage systems. Event driven DOM inputs can have substantial adverse effects on water quality. Despite this, DOM from important catchment sources such as road drains and Combined Sewage Overflows (CSO's) remains poorly characterised within urban watersheds. We studied DOM sources within an urbanised, headwater watershed in Birmingham, UK. Samples from terrestrial sources (roads, roofs and a CSO), were collected manually after the onset of rainfall events of varying magnitude, and again within 24-hrs of the event ending. Terrestrial samples were analysed for fluorescence, absorbance and Dissolved Organic Carbon (DOC) concentration. Fluorescence and absorbance indices were calculated, and Parallel Factor Analysis (PARAFAC) was undertaken to aid sample characterization. Substantial differences in fluorescence, absorbance, and DOC were observed between source types. PARAFAC-derived components linked to organic pollutants were generally highest within road derived samples, whilst humic-like components tended to be highest within roof samples. Samples taken from the CSO generally contained low fluorescence, however this likely represents a dilution effect. Variation within source groups was particularly high, and local land use seemed to be the driving factor for road and roof drain DOM character and DOC quantity. Furthermore, high variation in fluorescence, absorbance and DOC was apparent between all sources depending on event type. Drier antecedent conditions in particular were linked to greater presence of terrestrially-derived components and higher DOC content. Our study indicates that high variations in DOM character occur between source types, and over small spatial scales. Road drains located on main roads appear to contain the poorest quality DOM of the sources studied due to the presence of hydrocarbons. In order to prevent storm-derived DOM degradation of water quality of urban streams, greater knowledge of links between these drainage sources, and their pathways to streams is required.

Abandoned mine drainage in the Swatara Creek Basin, southern anthracite coalfield, Pennsylvania, USA: 2. performance of treatment systems

USGS Publications Warehouse

Cravotta, Charles A.

2010-01-01

A variety of passive and semi-passive treatment systems were constructed by state and local agencies to neutralize acidic mine drainage (AMD) and reduce the transport of dissolved metals in the upper Swatara Creek Basin in the Southern Anthracite Coalfield in eastern Pennsylvania. To evaluate the effectiveness of selected treatment systems installed during 1995–2001, the US Geological Survey collected water-quality data at upstream and downstream locations relative to each system eight or more times annually for a minimum of 3 years at each site during 1996–2007. Performance was normalized among treatment types by dividing the acid load removed by the size of the treatment system. For the limestone sand, open limestone channel, oxic limestone drain, anoxic limestone drain (ALD), and limestone diversion well treatment systems, the size was indicated by the total mass of limestone; for the aerobic wetland systems, the size was indicated by the total surface area of ponds and wetlands. Additionally, the approximate cost per tonne of acid treated over an assumed service life of 20 years was computed. On the basis of these performance metrics, the limestone sand, ALD, oxic limestone drain, and limestone diversion wells had similar ranges of acid-removal efficiency and cost efficiency. However, the open limestone channel had lower removal efficiency and higher cost per ton of acid treated. The wetlands effectively attenuated metals transport but were relatively expensive considering metrics that evaluated acid removal and cost efficiency. Although the water-quality data indicated that all treatments reduced the acidity load from AMD, the ALD was most effective at producing near-neutral pH and attenuating acidity and dissolved metals. The diversion wells were effective at removing acidity and increasing pH of downstream water and exhibited unique potential to treat moderate to high flows associated with storm flow conditions.

Evaluation of SCS-CN method using a fully distributed physically based coupled surface-subsurface flow model

NASA Astrophysics Data System (ADS)

Shokri, Ali

2017-04-01

The hydrological cycle contains a wide range of linked surface and subsurface flow processes. In spite of natural connections between surface water and groundwater, historically, these processes have been studied separately. The current trend in hydrological distributed physically based model development is to combine distributed surface water models with distributed subsurface flow models. This combination results in a better estimation of the temporal and spatial variability of the interaction between surface and subsurface flow. On the other hand, simple lumped models such as the Soil Conservation Service Curve Number (SCS-CN) are still quite common because of their simplicity. In spite of the popularity of the SCS-CN method, there have always been concerns about the ambiguity of the SCS-CN method in explaining physical mechanism of rainfall-runoff processes. The aim of this study is to minimize these ambiguity by establishing a method to find an equivalence of the SCS-CN solution to the DrainFlow model, which is a fully distributed physically based coupled surface-subsurface flow model. In this paper, two hypothetical v-catchment tests are designed and the direct runoff from a storm event are calculated by both SCS-CN and DrainFlow models. To find a comparable solution to runoff prediction through the SCS-CN and DrainFlow, the variance between runoff predictions by the two models are minimized by changing Curve Number (CN) and initial abstraction (Ia) values. Results of this study have led to a set of lumped model parameters (CN and Ia) for each catchment that is comparable to a set of physically based parameters including hydraulic conductivity, Manning roughness coefficient, ground surface slope, and specific storage. Considering the lack of physical interpretation in CN and Ia is often argued as a weakness of SCS-CN method, the novel method in this paper gives a physical explanation to CN and Ia.

Long-term characterization of residential runoff and assessing potential surrogates of fecal indicator organisms.

PubMed

Reano, Dane C; Haver, Darren L; Oki, Lorence R; Yates, Marylynn V

2015-05-01

Investigations into the microbiological impacts of urban runoff on receiving water bodies, especially during storm conditions, have yielded general paradigms that influence runoff abatement and control management strategies. To determine whether these trends are present in other runoff sources, the physical, chemical, and microbiological components of residential runoff from eight neighborhoods in Northern and Southern California were characterized over the course of five years. Sampling occurred regularly and during storm events, resulting in 833 data sets. Analysis of runoff data assisted in characterizing residential runoff, elucidating differences between dry and storm conditions, and identifying surrogates capable of assessing microbiological quality. Results indicate that although microbial loading increases during storm events similar to urban runoff, annual microbial loading in these study sites principally occurs during dry conditions (24% storm, 76% dry). Generated artificial neural network and multiple linear regression models assessed surrogate performance by accurately predicting Escherichia coli concentrations from validation data sets (R(2) = 0.74 and 0.77, respectively), but required input from other fecal indicator organism (FIO) variables to maintain performance (R(2) = 0.27 and 0.18, respectively, without FIO). This long-term analysis of residential runoff highlights characteristics distinct from urban runoff and establishes necessary variables for determining microbiological quality, thus better informing future management strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Distribution of dust during two dust storms in Iceland

NASA Astrophysics Data System (ADS)

Ösp Magnúsdóttir, Agnes; Dagsson-Waldhauserova, Pavla; Arnalds, Ólafur; Ólafsson, Haraldur

2017-04-01

Particulate matter mass concentrations and size fractions of PM1, PM2.5, PM4, PM10, and PM15 measured in transversal horizontal profile of two dust storms in southwestern Iceland are presented. Images from a camera network were used to estimate the visibility and spatial extent of measured dust events. Numerical simulations were used to calculate the total dust flux from the sources as 180,000 and 280,000 tons for each storm. The mean PM15 concentrations inside of the dust plumes varied from 10 to 1600 ?g?m?3 (PM10 = 7 to 583 ?g?m?3). The mean PM1 concentrations were 97-241 ?g?m?3 with a maximum of 261 ?g?m?3 for the first storm. The PM1/PM2.5 ratios of >0.9 and PM1/PM10 ratios of 0.34-0.63 show that suspension of volcanic materials in Iceland causes air pollution with extremely high PM1 concentrations, similar to polluted urban areas in Europe or Asia. Icelandic volcanic dust consists of a higher proportion of submicron particles compared to crustal dust. Both dust storms occurred in relatively densely inhabited areas of Iceland. First results on size partitioning of Icelandic dust presented here should challenge health authorities to enhance research in relation to dust and shows the need for public dust warning systems.

A Geospatial Database that Supports Derivation of Climatological Features of Severe Weather

NASA Astrophysics Data System (ADS)

Phillips, M.; Ansari, S.; Del Greco, S.

2007-12-01

The Severe Weather Data Inventory (SWDI) at NOAA's National Climatic Data Center (NCDC) provides user access to archives of several datasets critical to the detection and evaluation of severe weather. These datasets include archives of: · NEXRAD Level-III point features describing general storm structure, hail, mesocyclone and tornado signatures · National Weather Service Storm Events Database · National Weather Service Local Storm Reports collected from storm spotters · National Weather Service Warnings · Lightning strikes from Vaisala's National Lightning Detection Network (NLDN) SWDI archives all of these datasets in a spatial database that allows for convenient searching and subsetting. These data are accessible via the NCDC web site, Web Feature Services (WFS) or automated web services. The results of interactive web page queries may be saved in a variety of formats, including plain text, XML, Google Earth's KMZ, standards-based NetCDF and Shapefile. NCDC's Storm Risk Assessment Project (SRAP) uses data from the SWDI database to derive gridded climatology products that show the spatial distributions of the frequency of various events. SRAP also can relate SWDI events to other spatial data such as roads, population, watersheds, and other geographic, sociological, or economic data to derive products that are useful in municipal planning, emergency management, the insurance industry, and other areas where there is a need to quantify and qualify how severe weather patterns affect people and property.

Characteristics of the low latitude ionospheric storm in the East-Asian region

NASA Astrophysics Data System (ADS)

Zhao, B.; Wan, W.; Liu, L.

2009-04-01

First, an classification of ionospheric storm effects in the sub-equatorial ionization anomaly(SEIA) region at 120°E has been performed through the analysis of ionogram data at two ionosonde stations, Wuhan (114.4°, 30.5°) and Chung-Li (121.2°, 25°), and total electron content (TEC) derived from GPS network distributed around 120°E during the year 1999-2004. Three types of negative phase are identified. One is shown to be varied in phase of F-layer height variation and the other two out of phase. Two types of positive phase are also found. The mechanisms to cause these types of ionospheric effects has been considered to be related with storm meridional thermospheric wind including traveling atmosphere disturbance(TAD), electric fields and composition changes. Then based on the 50 years of ionosonde and 8 years of global ionospheric maps (GIMs) data, features of low latitude ionospheric storm were obtained. Results shows that positive phases during 18:00-2400 LT with its center near the 21:00 LT and 24:00-08:00 LT with its center near the sunrise time have predomination in controlling the storm behavior at low latitudes. It is shown that the distortion of EIA under the effects of the above factors have significant influence on the behavior of SEIA ionogram parameters.

Eddy covariance flux measurements of net ecosystem carbon dioxide exchange from a lowland peatland flux tower network in England and Wales

NASA Astrophysics Data System (ADS)

Morrison, Ross; Balzter, Heiko; Burden, Annette; Callaghan, Nathan; Cumming, Alenander; Dixon, Simon; Evans, Jonathan; Kaduk, Joerg; Page, Susan; Pan, Gong; Rayment, Mark; Ridley, Luke; Rylett, Daniel; Worrall, Fred; Evans, Christopher

2016-04-01

Peatlands store disproportionately large amounts of soil carbon relative to other terrestrial ecosystems. Over recent decades, the large amount of carbon stored as peat has proved vulnerable to a range of land use pressures as well as the increasing impacts of climate change. In temperate Europe and elsewhere, large tracts of lowland peatland have been drained and converted to agricultural land use. Such changes have resulted in widespread losses of lowland peatland habitat, land subsidence across extensive areas and the transfer of historically accumulated soil carbon to the atmosphere as carbon dioxide (CO2). More recently, there has been growth in activities aiming to reduce these impacts through improved land management and peatland restoration. Despite a long history of productive land use and management, the magnitude and controls on greenhouse gas emissions from lowland peatland environments remain poorly quantified. Here, results of surface-atmosphere measurements of net ecosystem CO2 exchange (NEE) from a network of seven eddy covariance (EC) flux towers located at a range of lowland peatland ecosystems across the United Kingdom (UK) are presented. This spatially-dense peatland flux tower network forms part of a wider observation programme aiming to quantify carbon, water and greenhouse gas balances for lowland peatlands across the UK. EC measurements totalling over seventeen site years were obtained at sites exhibiting large differences in vegetation cover, hydrological functioning and land management. The sites in the network show remarkable spatial and temporal variability in NEE. Across sites, annual NEE ranged from a net sink of -194 ±38 g CO2-C m-2 yr-1 to a net source of 784±70 g CO2-C m-2 yr-1. The results suggest that semi-natural sites remain net sinks for atmospheric CO2. Sites that are drained for intensive agricultural production range from a small net sink to the largest observed source for atmospheric CO2 within the flux tower network. Extensively managed grassland and a site that was restored from intensive arable land use represent modest CO2 sources. Temporal variations in CO2 fluxes at sites with permanent vegetation cover are coupled to seasonal and interannual variations in weather conditions and phenology. The type of crop produced and agricultural management drive large temporal differences in the CO2 fluxes of croplands on drained lowland peat soils. The main environmental controls on the spatial and temporal variations in CO2 exchange processes will be discussed.

A dural lymphatic vascular system that drains brain interstitial fluid and macromolecules

PubMed Central

Aspelund, Aleksanteri; Antila, Salli; Proulx, Steven T.; Karlsen, Tine Veronica; Karaman, Sinem; Detmar, Michael; Wiig, Helge

2015-01-01

The central nervous system (CNS) is considered an organ devoid of lymphatic vasculature. Yet, part of the cerebrospinal fluid (CSF) drains into the cervical lymph nodes (LNs). The mechanism of CSF entry into the LNs has been unclear. Here we report the surprising finding of a lymphatic vessel network in the dura mater of the mouse brain. We show that dural lymphatic vessels absorb CSF from the adjacent subarachnoid space and brain interstitial fluid (ISF) via the glymphatic system. Dural lymphatic vessels transport fluid into deep cervical LNs (dcLNs) via foramina at the base of the skull. In a transgenic mouse model expressing a VEGF-C/D trap and displaying complete aplasia of the dural lymphatic vessels, macromolecule clearance from the brain was attenuated and transport from the subarachnoid space into dcLNs was abrogated. Surprisingly, brain ISF pressure and water content were unaffected. Overall, these findings indicate that the mechanism of CSF flow into the dcLNs is directly via an adjacent dural lymphatic network, which may be important for the clearance of macromolecules from the brain. Importantly, these results call for a reexamination of the role of the lymphatic system in CNS physiology and disease. PMID:26077718

A dural lymphatic vascular system that drains brain interstitial fluid and macromolecules.

PubMed

Aspelund, Aleksanteri; Antila, Salli; Proulx, Steven T; Karlsen, Tine Veronica; Karaman, Sinem; Detmar, Michael; Wiig, Helge; Alitalo, Kari

2015-06-29

The central nervous system (CNS) is considered an organ devoid of lymphatic vasculature. Yet, part of the cerebrospinal fluid (CSF) drains into the cervical lymph nodes (LNs). The mechanism of CSF entry into the LNs has been unclear. Here we report the surprising finding of a lymphatic vessel network in the dura mater of the mouse brain. We show that dural lymphatic vessels absorb CSF from the adjacent subarachnoid space and brain interstitial fluid (ISF) via the glymphatic system. Dural lymphatic vessels transport fluid into deep cervical LNs (dcLNs) via foramina at the base of the skull. In a transgenic mouse model expressing a VEGF-C/D trap and displaying complete aplasia of the dural lymphatic vessels, macromolecule clearance from the brain was attenuated and transport from the subarachnoid space into dcLNs was abrogated. Surprisingly, brain ISF pressure and water content were unaffected. Overall, these findings indicate that the mechanism of CSF flow into the dcLNs is directly via an adjacent dural lymphatic network, which may be important for the clearance of macromolecules from the brain. Importantly, these results call for a reexamination of the role of the lymphatic system in CNS physiology and disease. © 2015 Aspelund et al.

Hydrogeology, water quality, and ecology of Anderton Branch near the Quail Hollow Landfill, Bedford County, Tennessee, 1995-99

USGS Publications Warehouse

Farmer, James

2004-01-01

The Quail Hollow Landfill, located in southeastern Bedford County on the Highland Rim overlooking the Central Basin karst region of Tennessee, is constructed on the gravelly, clay-rich residuum of the Fort Payne Formation of Mississippian age. A conceptual hydrologic model of the landfill indicated that Anderton Branch was at risk of being affected by the landfill. Ground water flowing beneath the landfill mixes with percolating rainwater that has passed through the landfill and discharges to the surface from numerous weeps, seeps, and springs present in the area. Anderton Branch, adjacent to the landfill site on the north and east, receives most of the discharge from these weeps, seeps, and springs. Anderton Branch also receives water from the Powell Branch drainage basin to the west and south because of diverted flow of ground water through Harrison Spring Cave. The U.S. Geological Survey, in cooperation with the Bedford County Solid Waste Authority, conducted a study to evaluate the effect of the Quail Hollow Landfill on ground- and surface-water quality. During storm runoff, specific conductance was elevated, and cadmium, iron, manganese, lead, and nickel concentrations in Anderton Branch frequently exceeded maximum contaminant levels for drinking water for the State of Tennessee. High chloride inputs to Anderton Branch were detected at two locations?a barnyard straddling the stream and a tributary draining a pond that receives water directly from the landfill. The chloride inputs probably contribute to chloride load levels that are three times higher for Anderton Branch than for the control stream Anthony Branch. Although toxic volatile organic compounds were detected in water from monitoring wells at the landfill, no organic contaminants were detected in domestic water wells adjacent to the landfill or in Anderton Branch. Sons Spring, a karst spring near the landfill, has been affected by the landfill as indicated by an increase in chloride concentrations from 4 milligrams per liter in 1974 to 59 milligrams per liter in 1996. Analysis of water samples from Sons Spring detected concentrations of nickel that exceeded primary drinking-water standards and Tennessee Department of Environment and Conservation fish and aquatic life chronic standards. Trichloroethene, 1,1-dichloroethene, and 1,1-dichloroethane also were detected at Sons Spring. The presence of these chlorinated solvents imply the landfill origin of the contaminants in Sons Spring. Continuous monitoring at Sons Spring indicated a pattern of decreased specific conductance and lower contaminant concentrations after a storm. Contaminant concentrations increased with specific conductance to pre-storm levels after several days. The benthic macroinvertebrate community in Anderton Branch adjacent to the landfill was not different from the communities at control sites upstream and in Anthony Branch. Sons Spring, however, has low abundance and numbers of benthic macroinvertebrate taxa. Toxicity studies using Ceriodaphnia dubia indicated no toxicity in the base flow or storm water in Anderton Branch or in a tributary draining a pond that receives water from the landfill and Sons Spring; however, water collected from Sons Spring resulted in 100 percent mortality to all organisms within 48 hours. High concentrations of nickel were detected in crayfish tissue from control sites and Anderton Branch. Analysis of sediment samples also indicates nickel concentrations are high at control sites upstream of the landfill. Increased levels of the biomarker metallothionein detected in crayfish from Anderton Branch likely are not caused by nickel or cadmium because the levels present in the tissue are not correlated with metallothionein levels. Despite the high levels of certain metals in Anderton Branch during storm flow, the lack of toxicity and the health of the benthic community imply no detectable negative effect from the landfill to the stream. Sons Spring, howe

Particulate Organic Matter Composition in Stream Runoff Following Large Storms: Role of POM Sources, Particle Size, and Event Characteristics

NASA Astrophysics Data System (ADS)

Johnson, Erin R.; Inamdar, Shreeram; Kan, Jinjun; Vargas, Rodrigo

2018-02-01

Large storm events possess significant erosive energy capable of mobilizing large amounts of sediment and particulate organic matter (POM) into fluvial systems. This study investigated how stream POM composition varied as a function of the watershed POM source, particle size, storm event magnitude, and seasonal timing. POM composition was characterized for multiple watershed sources and for stream POM following storms in a second-order forested stream. Carbon (C) and nitrogen (N) amount, C:N ratio and isotopic content (13C and 15N) were determined for solid phase POM, whereas dissolved organic C, total N concentrations, and fluorescence characteristics were determined for solution/extracted POM. Key findings from this study were the following: (1) Composition of POM varied greatly with watershed sources with forest floor litter being C and N rich and labile, while stream banks and bed were C and N poor and recalcitrant. (2) Summer storms mobilized more carbon and nitrogen-rich labile sources, while winter events mobilized more carbon- and nitrogen-poor refractory material from near-stream sources. (3) POM composition varied by size class, with the coarse POM showing more C and N rich and labile properties, while the fine POM displayed more degraded and refractory properties. If climate variability increases the magnitude and intensity of large storm events, our observations suggest that this will not only increase the inputs of POM to aquatic systems but also result in the delivery of coarser, C and N rich, and more bioavailable POM to the stream drainage network.

Observations of Two Sprite-Producing Storms in Colorado

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Lyons, Walter A.; Cummer, Steven A.; Fuchs, Brody R.; Dolan, Brenda; Rutledge, Steven A.; Krehbiel, Paul; Rison, William; Stanley, Mark; Ashcraft, Thomas

2016-01-01

Two sprite-producing thunderstorms were observed on 8 and 25 June 2012 in northeastern Colorado by a combination of low-light cameras, a lightning mapping array, polarimetric and Doppler radars, the National Lightning Detection Network, and charge moment change measurements. The 8 June event evolved from a tornadic hailstorm to a larger multicellular system that produced 21 observed positive sprites in 2 h. The majority of sprites occurred during a lull in convective strength, as measured by total flash rate, flash energy, and radar echo volume. Mean flash area spiked multiple times during this period; however, total flash rates still exceeded 60 min(sup 1), and portions of the storm featured a complex anomalous charge structure, with midlevel positive charge near 20degC. The storm produced predominantly positive cloud-to-ground lightning. All sprite-parent flashes occurred on the northeastern flank of the storm, where strong westerly upper level flow was consistent with advection of charged precipitation away from convection, providing a pathway for stratiform lightning. The 25 June event was another multicellular hailstorm with an anomalous charge structure that produced 26 positive sprites in less than 1 h. The sprites again occurred during a convective lull, with relatively weaker reflectivity and lower total flash rate but relatively larger mean flash area. However, all sprite parents occurred in or near convection and tapped charge layers in adjacent anvil cloud. The results demonstrate the sprite production by convective ground strokes in anomalously charged storms and also indicate that sprite production and convective vigor are inversely related in mature storms.

Monitoring Inland Storm Surge and Flooding from Hurricane Ike in Texas and Louisiana, September 2008

USGS Publications Warehouse

East, Jeffery W.; Turco, Michael J.; Mason, Jr., Robert R.

2008-01-01

The U.S. Geological Survey (USGS) deployed a temporary monitoring network of 117 pressure transducers (sensors) at 65 sites over an area of about 5,000 square miles to record the timing, areal extent, and magnitude of inland hurricane storm surge and coastal flooding generated by Hurricane Ike, which struck southeastern Texas and southwestern Louisiana September 12-13, 2008. Fifty-six sites were in Texas and nine were in Louisiana. Sites were categorized as surge, riverine, or beach/wave on the basis of proximity to the Gulf Coast. One-hundred five sensors from 59 sites (fig. 1) were recovered; 12 sensors from six sites either were lost during the storm or were not retrieved. All 59 sites (41 surge, 10 riverine, 8 beach/wave) had sensors to record water pressure (fig. 2), which is expressed as water level in feet above North American Vertical Datum of 1988 (NAVD88), and 46 sites had an additional sensor to record barometric pressure, expressed in pounds per square inch. Figure 3 shows an example of water level and barometric pressure over time recorded by sensors during the storm.

Spatial variability of herbicide mobilisation and transport at catchment scale: insights from a field experiment

NASA Astrophysics Data System (ADS)

Doppler, T.; Camenzuli, L.; Hirzel, G.; Krauss, M.; Lück, A.; Stamm, C.

2012-07-01

During rain events, herbicides can be transported from their point of application to surface waters, where they may harm aquatic organisms. Since the spatial pattern of mobilisation and transport is heterogeneous, the contributions of different fields to the herbicide load in the stream may vary considerably within one catchment. Therefore, the prediction of contributing areas could help to target mitigation measures efficiently to those locations where they reduce herbicide pollution the most. Such spatial predictions require sufficient insight into the underlying transport processes. To improve the understanding of the process chain of herbicide mobilisation on the field and the subsequent transport through the catchment to the stream, we performed a controlled herbicide application on corn fields in a small agricultural catchment (ca. 1 km2) with intensive crop production in the Swiss Plateau. Water samples were collected at different locations in the catchment (overland flow, tile drains and open channel) for two months after application in 2009, with a high temporal resolution during rain events. We also analysed soil samples from the experimental fields and measured discharge, groundwater level, soil moisture and the occurrence of overland flow at several locations. Several rain events with varying intensities and magnitudes occurred during the study period. Overland flow and erosion were frequently observed in the entire catchment. Infiltration excess and saturation excess overland flow were both observed. However, the main herbicide loss event was dominated by infiltration excess. Despite the frequent and wide-spread occurrence of overland flow, most of this water did not reach the channel directly, but was retained in small depressions in the catchment. From there, it reached the stream via macropores and tile drains. Manholes of the drainage system and storm drains for road and farmyard runoff acted as additional shortcuts to the stream. Although fast flow processes such as overland and macropore flow reduce the influence of the herbicide's chemical properties on transport due to short travel times, sorption properties influenced the herbicide transfer from ponding overland flow to tile drains (macropore flow). However, no influence of sorption was observed during the mobilisation of the herbicides from soil to overland flow. These observations on the role of herbicide properties contradict previous findings to some degree. Furthermore, they demonstrate that valuable insight can be gained by making spatially detailed observations along the flow paths.

Cloud-to-ground lightning and surface rainfall in warm-season Florida thunderstorms

USGS Publications Warehouse

Gungle, B.; Krider, E.P.

2006-01-01

Relationships between cloud-to-ground (CG) lightning and surface rainfall have been examined in nine isolated, warm-season thunderstorms on the east coast of central Florida. CG flashes and the associated rain volumes were measured as a function of time in storm-centered reference frames that followed each storm over a network of rain gauges. Values of the storm-average rain volume per CG flash ranged from 0.70 ?? 104 to 6.4 ?? 104 m3/CG flash, with a mean (and standard deviation) of 2.6 ?? 104 ?? 2.1 ?? 104 m3/CG flash. Values of the rain volume concurrent with CG flashes ranged from 0.11 ?? 104 to 4.9 ?? 104 m3/CG flash with a mean of 2.1 ?? 104 ?? 2.0 ?? 104 m3/CG flash. The lag-time between the peak CG flash rate and the peak rainfall rate (using 5 min bins), and the results of a lag correlation analysis, show that surface rainfall tends to follow the lightning (positive lag) by up to 20 min in six storms. In one storm the rainfall preceded the lightning by 5 min, and two storms had nonsignificant lags. Values of the lagged rain volume concurrent with CG flashes ranged from 0.43 ?? 104 to 4.9 ?? 104 m3/CG flash, and the mean was 1.9 ?? 104 ?? 1.7 ?? 104 m3/CG flash. For the five storms that produced 12 or more flashes and had significant lags, a plot of the optimum lag time versus the total number of CG flashes shows a linear trend (R2 = 0.56). The number of storms is limited, but the lag results do indicate that large storms tend to have longer lags. A linear fit to the lagged rain volume vs. the number of concurrent CG flashes has a slope of 1.9 ?? 104 m3/CG flash (R2 = 0.83). We conclude that warm-season Florida thunderstorms produce a roughly constant rain volume per CG flash and that CG lightning can be used to estimate the location and intensity of convective rainfall in that weather regime. Copyright 2006 by the American Geophysical Union.

The Aral Sea Disaster

NASA Astrophysics Data System (ADS)

Micklin, Philip

2007-05-01

The Aral Sea is a huge terminal lake located among the deserts of Central Asia. Over the past 10 millennia, it has repeatedly filled and dried, owing both to natural and human forces. The most recent desiccation started in the early 1960s and owes overwhelmingly to the expansion of irrigation that has drained its two tributary rivers. Lake level has fallen 23 m, area shrunk 74%, volume decreased 90%, and salinity grew from 10 to more than 100g/l, causing negative ecological changes, including decimation of native fish species, initiation of dust/salt storms, degradation of deltaic biotic communities, and climate change around the former shoreline. The population residing around the lake has also been negatively impacted. There is little hope in the foreseeable future to fully restore the Aral Sea, but measures to preserve/rehabilitate parts of the water body and the deltas are feasible.

Ecology of Lawrence Livermore Laboratoy

DOE Office of Scientific and Technical Information (OSTI.GOV)

McIntyre, D.R.

1977-03-10

The ecological impact of the Lawrence Livermore Laboratory on man, plants and animals, soil, water, and air has been on the positive side since the removal of much of the former airbase runway system. Many new trees have been planted, and the total biological energy has been increased. Although there has been destruction of some native plants, many new ecological niches have been formed. Cliff swallows, quail, and other birds have been able to find territories. Even a muskrat has appeared from the overflow storm drains. Opossums, brush rabbits, field mice, and predatory birds (kites, hawks, eagles, and sparrow hawks)more » are numerous. The use of herbicides and insecticides has upset the balance somewhat, but California poppies, owl clover, dragonflies, lacewings, bees, and wasps indicate that the effects are limited and that there is a wealth of animal life in the open areas and around the buildings.« less

Earth Observations taken by the Expedition 39 Crew

NASA Image and Video Library

2014-05-09

ISS039-E-019482 (9 May 2014) --- One of the Expedition 39 crew members aboard the Earth-orbiting International Space Station used a 400mm lens to take this photograph of Venice Lagoon, Italy on May 9, 2014. A narrow barrier island protects the Lagoon of Venice from storm waves in the northern Adriatic Sea, and breakwaters protect inlets to the lagoon. Red tiles of the roofs of the edifices on the island of Venice contrast with the grays of the mainland sister city of Mestre. The cities are joined by a prominent causeway. Another causeway joins the island to the airport (top right). Small bright agricultural fields of well drained soils (top left) contrast with the darker vegetation of back bay swamps where fishing is a popular pastime. Dense urban populations on its shores and heavy use by craft of all kinds result in turbid water in the northern half of the lagoon.

Effects of agricultural, industrial, and municipal pollutants on wetlands and wildlife and wildlife health

USGS Publications Warehouse

Converse, Kathryn A.

1995-01-01

Wetlands accumulate pollutants from adjacent areas through intentional discharge of sewage or industrial wastes, runoff of agricultural fertilizers and pesticides, and discharge from municipal storm drains.  Coastal wetlands receive more pollutants indirectly as the endpoint for upland drainage systems and directly through petroleum spills and insect abatement.  Wetlands that serve as evaporation basins during seasonally high water, especially in more arid climates, concentrate natural compounds and as well as pollutants.  The ability of wetlands to be effective filtration systems for wastewater nutrients through microbial transformations, uptake by plants, and deposition of particulate matter, and the shortage of water in arid climates has resulted in revision of wetland regulations.  Wetlands can now be developed for wastewater treatment and natural wetlands can be restored or converted to wastewater treatment systems.  The effect of these accumulation pollutants on wetland ecology and wildlife health needs to be recognized.

Integration of UAV photogrammetry and SPH modelling of fluids to study runoff on real terrains.

PubMed

Barreiro, Anxo; Domínguez, Jose M; C Crespo, Alejandro J; González-Jorge, Higinio; Roca, David; Gómez-Gesteira, Moncho

2014-01-01

Roads can experience runoff problems due to the intense rain discharge associated to severe storms. Two advanced tools are combined to analyse the interaction of complex water flows with real terrains. UAV (Unmanned Aerial Vehicle) photogrammetry is employed to obtain accurate topographic information on small areas, typically on the order of a few hectares. The Smoothed Particle Hydrodynamics (SPH) technique is applied by means of the DualSPHysics model to compute the trajectory of the water flow during extreme rain events. The use of engineering solutions to palliate flood events is also analysed. The study case simulates how the collected water can flow into a close road and how precautionary measures can be effective to drain water under extreme conditions. The amount of water arriving at the road is calculated under different protection scenarios and the efficiency of a ditch is observed to decrease when sedimentation reduces its depth.

Integration of UAV Photogrammetry and SPH Modelling of Fluids to Study Runoff on Real Terrains

PubMed Central

Barreiro, Anxo; Domínguez, Jose M.; C. Crespo, Alejandro J.; González-Jorge, Higinio; Roca, David; Gómez-Gesteira, Moncho

2014-01-01

Roads can experience runoff problems due to the intense rain discharge associated to severe storms. Two advanced tools are combined to analyse the interaction of complex water flows with real terrains. UAV (Unmanned Aerial Vehicle) photogrammetry is employed to obtain accurate topographic information on small areas, typically on the order of a few hectares. The Smoothed Particle Hydrodynamics (SPH) technique is applied by means of the DualSPHysics model to compute the trajectory of the water flow during extreme rain events. The use of engineering solutions to palliate flood events is also analysed. The study case simulates how the collected water can flow into a close road and how precautionary measures can be effective to drain water under extreme conditions. The amount of water arriving at the road is calculated under different protection scenarios and the efficiency of a ditch is observed to decrease when sedimentation reduces its depth. PMID:25372035

An Index of Longitudinal Hydrologic Connectivity to Evaluate Effects of Water Abstraction on Streams Dominated by Migratory Shrimps

NASA Astrophysics Data System (ADS)

Crook, K. E.; Pringle, C. M.; Freeman, M. C.; Scatena, F. N.

2005-05-01

Massive water withdrawals from streams draining the Caribbean National Forest (CNF), Puerto Rico, are threatening their biotic integrity. Migratory tropical shrimps are ideal indicator species to measure water withdrawal effects on riverine connectivity and biointegrity because: (1) their migratory range encompasses the stream network from estuaries to headwater streams; (2) they represent greater than 90% of biomass in streams draining the CNF; and (3) they facilitate important in-stream ecological processes. We developed an index to evaluate individual and cumulative effects of water intakes on each stage of the shrimp's life-cycle. Effect of water withdrawal on longitudinal connectivity was evaluated by combining effects of water withdrawal on larval and juvenile shrimps. Larvae require downstream transport to the estuary for advancement to the next life-stage, and juveniles similarly require access to headwater streams. Therefore, these two life-stages represent the bi-directional connectivity of streams from headwaters to estuaries. Seventeen water intakes were evaluated in and around the CNF. Larger intakes cause a greater decrease in connectivity than smaller intakes; however, several small, high elevation intakes had very low connectivity. Also, intakes with alternative designs, such as a French drain, have reduced effects on connectivity.

Eureka!

ERIC Educational Resources Information Center

Villano, Matt

2009-01-01

Academic technologists at Lynn University (Florida) learned the hard way just how important a disaster recovery plan can be. Back in 2005, when Hurricane Wilma walloped the region with driving rain and 120 mile-per-hour winds, the storm debilitated Lynn's IT department, causing damage and flooding that thwarted the campus network for nearly two…

Variations of total electron content during geomagnetic disturbances: A model/observation comparison

NASA Technical Reports Server (NTRS)

Roble, G. Lu X. Pi A. D. Richmond R. G.

1997-01-01

This paper studies the ionospheric response to major geomagnetic storm of October 18-19, 1995, using the thermosphere-ionosphere electrodynamic general circulation model (TIE-GCM) simulations and the global ionospheric maps (GIM) of total electron content (TEC) observations from the Global Positioning System (GPS) worldwide network.

Targeting sediment management strategies using sediment quantification and fingerprinting methods

NASA Astrophysics Data System (ADS)

Sherriff, Sophie; Rowan, John; Fenton, Owen; Jordan, Phil; hUallacháin, Daire Ó.

2016-04-01

Cost-effective sediment management is required to reduce excessive delivery of fine sediment due to intensive land uses such as agriculture, resulting in the degradation of aquatic ecosystems. Prioritising measures to mitigate dominant sediment sources is, however, challenging, as sediment loss risk is spatially and temporally variable between and within catchments. Fluctuations in sediment supply from potential sources result from variations in land uses resulting in increased erodibility where ground cover is low (e.g., cultivated, poached and compacted soils), and physical catchment characteristics controlling hydrological connectivity and transport pathways (surface and/or sub-surface). Sediment fingerprinting is an evidence-based management tool to identify sources of in-stream sediments at the catchment scale. Potential sediment sources are related to a river sediment sample, comprising a mixture of source sediments, using natural physico-chemical characteristics (or 'tracers'), and contributions are statistically un-mixed. Suspended sediment data were collected over two years at the outlet of three intensive agricultural catchments (approximately 10 km2) in Ireland. Dominant catchment characteristics were grassland on poorly-drained soils, arable on well-drained soils and arable on moderately-drained soils. High-resolution (10-min) calibrated turbidity-based suspended sediment and discharge data were combined to quantify yield. In-stream sediment samples (for fingerprinting analysis) were collected at six to twelve week intervals, using time-integrated sediment samplers. Potential sources, including stream channel banks, ditches, arable and grassland field topsoils, damaged road verges and tracks were sampled, oven-dried (<40oC) and sieved (125 microns). Soil and sediment samples were analysed for mineral magnetics, geochemistry and radionuclide tracers, particle size distribution and soil organic carbon. Tracer data were corrected to account for particle size and organic matter selectivity processes. Contributions from potential sources type groups (channel - ditches and stream banks, roads - road verges and tracks, fields - grassland and arable topsoils) were statistically un-mixed using FR2000, an uncertainty-inclusive algorithm, and combined with sediment yield data. Results showed sediment contributions from channel, field and road groups were 70%, 25% and 5% in the poorly-drained catchment, 59%, 22% and 19% in the well-drained catchment, and 17%, 74% and 9% in the moderately-drained catchment. Higher channel contributions in the poorly-drained catchment were attributed to bank erosion accelerated by the rapid diversion of surface runoff into channels, facilitated by surface and sub-surface artificial drainage networks, and bank seepage from lateral pressure gradients due to confined groundwater. Despite the greatest proportion of arable soils in the well-drained catchment, this source was frequently hydrologically disconnected as well-drained soils largely infiltrated rainfall and prevented surface soil erosion. Periods of high and intense rainfall were associated with greater proportions of field losses in the well-drained catchment likely due to infiltration exceeding the saturated hydraulic conductivity of soils and establishment of surface hydrological connectivity. Losses from field topsoils dominated in the moderately-drained catchment as antecedent soil wetness maintained surface flow pathways and coincided with low groundcover on arable soils. For cost-effective management of sediment pressures to aquatic ecosystems, catchment specific variations in sediment sources must be considered.

Convection index as a tool for trend analysis of intense summer storms in Switzerland

NASA Astrophysics Data System (ADS)

Gaal, Ladislav; Molnar, Peter; Szolgay, Jan

2013-04-01

Convective summer thunderstorms are generally responsible for the most devastating floods in urban and small natural catchments. In this study we focus on the identification of the nature and magnitude of changes in the properties of intense summer storms of convective character in Switzerland in the last three decades. The study is based on precipitation records from the SwissMetNet (MeteoSwiss) network at 63 stations that cover altitudes ranging from 200 up to 3300 m a.s.l. over the period 1981-2012 (32 years). Additionally, the same stations also measure the number of lightning strikes within a range of 30 km from each station. In an accompanying contribution we describe the method how intensive summer storms can be reliably selected out of all storms in long and high resolution precipitation time series. On the basis of the statistical distributions and dependence among key storm characteristics at the event scale (total rainfall depth R, storm duration D, and peak intensity I) and using high resolution lightning data as a surrogate we defined a threshold intensity I* that differentiates between the events accompanied with lightning with an acceptably small probability of misclassification. This allowed us to identify intense summer events with convective character as those where I > I* regardless of their duration or total rainfall depth. The current study makes use of the threshold intensity I* for the definition of a seasonal convection index at each station (Llasat, 2001). This index gives us a measure of 'convectiveness', i.e. the total precipitation depth coming from convective storms relative to the total precipitation depth of all summer storms. We computed the convection index at all 63 stations and analyzed the series for trends. We found that the seasonal convection index increases at most of the stations in Switzerland and in approximately 20% of the cases this increase is statistically significant. This is likely a consequence of the fact that the number of summer storms exceeding the threshold I* also shows an increasing tendency with a similar percentage of statistically significant changes. Although our analysis indicates an increasing tendency in the intensity and frequency of summer storms with convective character in Switzerland, it is not yet clear whether these can be traced to causal factors such as atmospheric warming, etc. This remains an open research question.

Assessment of flood hazard in a combined sewer system in Reykjavik city centre.

PubMed

Hlodversdottir, Asta Osk; Bjornsson, Brynjolfur; Andradottir, Hrund Olof; Eliasson, Jonas; Crochet, Philippe

2015-01-01

Short-duration precipitation bursts can cause substantial property damage and pose operational risks for wastewater managers. The objective of this study was to assess the present and possible future flood hazard in the combined sewer system in Reykjavik city centre. The catchment is characterised by two hills separated by a plain. A large portion of the pipes in the aging network are smaller than the current minimum diameter of 250 mm. Runoff and sewer flows were modelled using the MIKE URBAN software package incorporating both historical precipitation and synthetic storms derived from annual maximum rainfall data. Results suggest that 3% of public network manholes were vulnerable to flooding during an 11-year long rainfall sequence. A Chicago Design Storm (CDS) incorporating a 10-minute rainfall burst with a 5-year return period predicted twice as many flooded manholes at similar locations. A 20% increase in CDS intensity increased the number of flooded manholes and surface flood volume by 70% and 80%, respectively. The flood volume tripled if rainfall increase were combined with urban re-development, leading to a 20% increase in the runoff coefficient. Results highlight the need for reducing network vulnerabilities, which include decreased pipe diameters and low or drastically varying pipe grades.

Stream restoration and sanitary infrastructure alter sources and fluxes of water, carbon, and nutrients in urban watersheds

NASA Astrophysics Data System (ADS)

Pennino, M. J.; Kaushal, S. S.; Mayer, P. M.; Utz, R. M.; Cooper, C. A.

2015-12-01

An improved understanding of sources and timing of water and nutrient fluxes associated with urban stream restoration is critical for guiding effective watershed management. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in stream restoration and sanitary infrastructure. We compared a restored stream with 3 unrestored streams draining urban development and stormwater management over a 3 year period. We found that there was significantly decreased peak discharge in response to precipitation events following stream restoration. Similarly, we found that the restored stream showed significantly lower monthly peak runoff (9.4 ± 1.0 mm d-1) compared with two urban unrestored streams (ranging from 44.9 ± 4.5 to 55.4 ± 5.8 mm d-1) draining higher impervious surface cover. Peak runoff in the restored stream was more similar to a less developed stream draining extensive stormwater management (13.2 ± 1.9 mm d-1). Interestingly, the restored stream exported most carbon, nitrogen, and phosphorus loads at relatively lower streamflow than the 2 more urban streams, which exported most of their loads at higher and less frequent streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha-1 yr-1), total nitrogen (4.5 ± 0.3 kg ha-1 yr-1), and total phosphorus (161 ± 15 g ha-1 yr-1) were significantly lower in the restored stream compared to both urban unrestored streams (p < 0.05) and similar to the stream draining stormwater management. Although stream restoration appeared to potentially influence hydrology to some degree, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the restored stream was derived from leaky sanitary sewers (during baseflow), similar to the unrestored streams. Longitudinal synoptic surveys of water and nitrate isotopes along all 4 watersheds suggested the importance of urban groundwater contamination from leaky piped infrastructure. Urban groundwater contamination was also suggested by additional tracer measurements including fluoride (added to drinking water) and iodide (contained in dietary salt). Our results suggest that integrating stream restoration with restoration of aging sanitary infrastructure can be critical to more effectively minimize watershed nutrient export. Given that both stream restoration and sanitary pipe repairs both involve extensive channel manipulation, they can be considered simultaneously in management strategies. In addition, ground water can be a major source of nutrient fluxes in urban watersheds, which has been less considered compared with upland sources and storm drains. Goundwater sources, fluxes, and flowpath should also be targeted in efforts to improve stream restoration strategies and prioritize hydrologic "hot spots" along watersheds where stream restoration is most likely to succeed.

Streamflow characteristics of streams in the Helmand Basin, Afghanistan

USGS Publications Warehouse

Williams-Sether, Tara

2008-01-01

A majority of the Afghan population lacks adequate and safe supplies of water because of contamination, lack of water-resources management regulation, and lack of basic infrastructure, compounded by periods of drought and seasonal flooding. Characteristics of historical streamflows are needed to assist with efforts to quantify the water resources of the Helmand Basin. The Helmand Basin is the largest river basin in Afghanistan. It comprises the southern half of the country, draining waters from the Sia Koh Mountains in Herat Province to the eastern mountains in Gardez Province (currently known as the Paktia Province) and the Parwan Mountains northwest of Kabul, and finally draining into the unique Sistan depression between Iran and Afghanistan (Favre and Kamal, 2004). The Helmand Basin is a desert environment with rivers fed by melting snow from the high mountains and infrequent storms. Great fluctuations in streamflow, from flood to drought, can occur annually. Knowledge of the magnitude and time distribution of streamflow is needed to quantify water resources and for water management and environmental planning. Agencies responsible for the development and management of Afghanistan's surface-water resources can use this knowledge for making safe, economical, and environmentally sound water-resource planning decisions. To provide the Afghan managers with necessary streamflow information, the U.S. Geological Survey (USGS), in cooperation with the U.S. Agency for International Development (USAID), computed streamflow statistics for data collected at historical gaging stations within the Helmand Basin. The historical gaging stations used are shown in figure 1 and listed in table 1.

Municipal solid waste management in Lahore City District, Pakistan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Batool, Syeda Adila; Muhammad Nawaz Ch

2009-06-15

This study deals with generation, composition, collection, transportation, and disposal, as well as the present cost of the waste management on the basis of 60% collection of the total waste and the cost of proposed improved system of management on the basis of 100% waste collection using the IWM-2 LCI model. A GIS map of Data Ganj Bakhsh Town (DGBT) of Lahore City District showing communal storage facilities is also provided. DGBT has a population of 1,624,169 living in 232,024 dwellings. The total waste generated per year is 500,000 tons, or 0.84/kg/cap/day. Presently 60% of the MSW is collected andmore » disposed in open dumps, while 40% is not collected and lies along roadsides, streets railway lines, depressions, vacant plots, drains, storm drains and open sewers. In DGBT, 129 containers of 5-m{sup 3} capacity, 120 containers of 10-m{sup 3} capacity and 380 skips of 2.5-m{sup 3} capacity are placed for waste collection. The overall collection and disposal cost of the MSW of DGBT is $3,177,900/yr, which is $10.29/ton. Modeling was conducted using the IWM-2 model for improved collection and disposal on the basis of 100% service, compared to the current 60% service. The modelled cost is $8.3/per ton, which is 20% less than the present cost, but the overall cost of 100% collection and disposal increases to $4,155,737/yr.« less

New fronts emerge in the influenza cytokine storm.

PubMed

Guo, Xi-Zhi J; Thomas, Paul G

2017-07-01

Influenza virus is a significant pathogen in humans and animals with the ability to cause extensive morbidity and mortality. Exuberant immune responses induced following infection have been described as a "cytokine storm," associated with excessive levels of proinflammatory cytokines and widespread tissue damage. Recent studies have painted a more complex picture of cytokine networks and their contributions to clinical outcomes. While many cytokines clearly inflict immunopathology, others have non-pathological delimited roles in sending alarm signals, facilitating viral clearance, and promoting tissue repair, such as the IL-33-amphiregulin axis, which plays a key role in resolving some types of lung damage. Recent literature suggests that type 2 cytokines, traditionally thought of as not involved in anti-influenza immunity, may play an important regulatory role. Here, we discuss the diverse roles played by cytokines after influenza infection and highlight new, serene features of the cytokine storm, while highlighting the specific functions of relevant cytokines that perform unique immune functions and may have applications for influenza therapy.

Deciphering the expression of climate change within the Lower Colorado River basin by stochastic simulation of convective rainfall

NASA Astrophysics Data System (ADS)

Bliss Singer, Michael; Michaelides, Katerina

2017-10-01

In drylands, convective rainstorms typically control runoff, streamflow, water supply and flood risk to human populations, and ecological water availability at multiple spatial scales. Since drainage basin water balance is sensitive to climate, it is important to improve characterization of convective rainstorms in a manner that enables statistical assessment of rainfall at high spatial and temporal resolution, and the prediction of plausible manifestations of climate change. Here we present a simple rainstorm generator, STORM, for convective storm simulation. It was created using data from a rain gauge network in one dryland drainage basin, but is applicable anywhere. We employ STORM to assess watershed rainfall under climate change simulations that reflect differences in wetness/storminess, and thus provide insight into observed or projected regional hydrologic trends. Our analysis documents historical, regional climate change manifesting as a multidecadal decline in rainfall intensity, which we suggest has negatively impacted ephemeral runoff in the Lower Colorado River basin, but has not contributed substantially to regional negative streamflow trends.

Angioarchitectural changes in subacute cerebral venous thrombosis. A synchrotron-based micro- and nano-CT study.

PubMed

Stolz, Erwin; Yeniguen, Mesut; Kreisel, Melanie; Kampschulte, Marian; Doenges, Simone; Sedding, Daniel; Ritman, Erik L; Gerriets, Tibo; Langheinrich, Alexander C

2011-02-01

It is well known that recanalization of thrombosed cerebral sinuses occurs early but without marked influence on the long-term outcome and on final venous infarct volume on magnetic resonance imaging. To better understand the possible microvascular mechanisms behind these clinical observations, we evaluated the sequels of subacute superior sagittal sinus (SSS) thrombosis in rats using micro- and nano-CT imaging of the same specimen to provide large volume and high resolution CT image data respectively. SSS thrombosis was induced in 11 animals which were euthanized after 6h (n=4) or 6 weeks (n=7). Eight sham-operated rats served as controls. After infusion of contrast into the vasculature of the brains, these were isolated and scanned using micro-, nano-, and synchrotron-based micro-CT ((8 μm³), (900 nm)³, and (1.9 μm³) voxel sizes). The cross-sectional area of the superior sagittal sinus, microvessels and cortical veins were quantified. Tissue sections were stained against VEGF antigen. Immunohistochemistry was confirmed using quantitative rtPCR. SSS thrombosis led to a congestion of the bridging veins after 6h. After 6 weeks, a network of small vessels surrounding the occluded SSS was present with concurrent return towards the diameter of the draining bridging veins of controls. This microvascular network connected to cortical veins as demonstrated by nano- and synchrotron-based micro-CT. Also the volume fraction and number of cortical veins increased significantly. Immunohistochemistry in the region of the microsvascular network demonstrated a strong immunoreactivity against VEGF, confirmed by rtPCR. The sequel of subacute SSS thrombosis induced a network of microvessels ("venogenesis") draining the bridging veins. Also the volume fraction of cortical veins increased significantly. Copyright © 2010 Elsevier Inc. All rights reserved.

Angioarchitectural Changes in Subacute Cerebral Venous Thrombosis. A Synchrotron-based Micro- and Nano-CT Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

E Stolz; M Yeniguen; M Kreisel

2011-12-31

It is well known that recanalization of thrombosed cerebral sinuses occurs early but without marked influence on the long-term outcome and on final venous infarct volume on magnetic resonance imaging. To better understand the possible microvascular mechanisms behind these clinical observations, we evaluated the sequels of subacute superior sagittal sinus (SSS) thrombosis in rats using micro- and nano-CT imaging of the same specimen to provide large volume and high resolution CT image data respectively. SSS thrombosis was induced in 11 animals which were euthanized after 6 h (n = 4) or 6 weeks (n = 7). Eight sham-operated rats servedmore » as controls. After infusion of contrast into the vasculature of the brains, these were isolated and scanned using micro-, nano-, and synchrotron-based micro-CT ((8 {mu}m{sup 3}), (900 nm){sup 3}, and (1.9 {mu}m{sup 3}) voxel sizes). The cross-sectional area of the superior sagittal sinus, microvessels and cortical veins were quantified. Tissue sections were stained against VEGF antigen. Immunohistochemistry was confirmed using quantitative rtPCR. SSS thrombosis led to a congestion of the bridging veins after 6 h. After 6 weeks, a network of small vessels surrounding the occluded SSS was present with concurrent return towards the diameter of the draining bridging veins of controls. This microvascular network connected to cortical veins as demonstrated by nano- and synchrotron-based micro-CT. Also the volume fraction and number of cortical veins increased significantly. Immunohistochemistry in the region of the microsvascular network demonstrated a strong immunoreactivity against VEGF, confirmed by rtPCR. The sequel of subacute SSS thrombosis induced a network of microvessels ('venogenesis') draining the bridging veins. Also the volume fraction of cortical veins increased significantly.« less

Do storage dynamics in hydropedological units control hydrological connectivity? (Invited)

NASA Astrophysics Data System (ADS)

Tetzlaff, D.; Birkel, C.; Dick, J.; Geris, J.; Soulsby, C.

2013-12-01

In many northern landscapes, peat-dominated riparian wetlands often characterise the zone of connection between terrestrial drainage and the river network. In order to understand the relationship between connectivity and stream flow generation in a montane headwater catchment, we examined the storage dynamics and isotopic composition of soil water in major hydropedological units. These formed a classic catena sequence for northern catchments from free-draining podzols on steep upper hillslopes through to peaty gleysols in lower receiving slopes to deeper peats (Histosols) in the riparian zone. The peaty gleys and peats remained saturated throughout the year, whilst the podzols showed distinct wetting and drying cycles. In this climatic region, most precipitation events are less than 10mm in magnitude, storm runoff is mainly generated from the Histosols and Gleysols, with runoff coefficients (RCs) typically <10%. In larger events the podzolic soils become strongly connected to the saturated areas and RCs can exceed 40%. Isotopic variations in precipitation are significantly damped in the organic-rich surface horizons of the soils due to mixing with larger volumes of stored water. This damping is accentuated in the deeper soil profile and groundwater. Consequently, the isotopic composition of stream water is also damped, but the strongly reflects that of the near surface waters in the riparian peats. Old 'pre-event' water generally accounts for >80% of flow, even in large events, mainly reflecting the displacement of water stored in the riparian peats and peaty gleys. These riparian areas appear to be the dominant zone where different catchment source waters mix; acting as an 'isostat' that regulates the isotopic composition of stream waters and integrates the Transit Time Distribution (TTD) for the catchment.

Tornadogenesis via squall line and supercell interaction revisited - The 15 November 1989 Huntsville tornado

NASA Technical Reports Server (NTRS)

Goodman, Steven J.; Knupp, Kevin R.

1990-01-01

A case study analyzing the environmental setting and storm system morphology that provides observational evidence of a mechanism involving the interaction of a gust front with a preexisting mesocyclone is presented. This case serves to reemphasize the existence of a high conditional probability of tornado occurrence, given the merger of a gust front (or storm outflow) with a moderate to strong thunderstorm ahead of it. The resultant data serve to illustrate some important unresolved issues relevant to the severe weather warning system that involve the present and planned local warning and network radars, and future algorithms that might intelligently integrate other data sources and models with the radar data.

Monitoring storm tide and flooding from Hurricane Sandy along the Atlantic coast of the United States, October 2012

USGS Publications Warehouse

McCallum, Brian E.; Wicklein, Shaun M.; Reiser, Robert G.; Busciolano, Ronald J.; Morrison, Jonathan; Verdi, Richard J.; Painter, Jaime A.; Frantz, Eric R.; Gotvald, Anthony J.

2013-01-01

The U.S. Geological Survey (USGS) deployed a temporary monitoring network of water-level and barometric pressure sensors at 224 locations along the Atlantic coast from Virginia to Maine to continuously record the timing, areal extent, and magnitude of hurricane storm tide and coastal flooding generated by Hurricane Sandy. These records were greatly supplemented by an extensive post-flood high-water mark (HWM) flagging and surveying campaign from November to December 2012 involving more than 950 HWMs. Both efforts were undertaken as part of a coordinated federal emergency response as outlined by the Stafford Act under a directed mission assignment by the Federal Emergency Management Agency (FEMA).

Auroras observations of the MAIN in Apatity during 2014/15 winter season

NASA Astrophysics Data System (ADS)

Guineva, V.; Despirak, I.; Kozelov, B.

2017-08-01

In this work we review substorms, originated during the 2014/2015 winter season. Observations of the Multiscale Aurora Imaging Network (MAIN) in Apatity have been used. Solar wind and interplanetary magnetic field parameters were estimated by the 1-min sampled OMNI data base from CDAWeb (http://cdaweb.gsfc.nasa.gov/cdaweb/ istp_public/). Auroral disturbances were verified by the 10-s sampled data of IMAGE magnetometers and by data of the all-sky camera at Apatity. Subject of the review were the peculiarities in the development of substorms occurred during different geomagnetic conditions. The behavior of the substorms developed in non-storm time and during different phases of geomagnetic storms was discussed.

Overview of the ARkStorm scenario

USGS Publications Warehouse

Porter, Keith; Wein, Anne; Alpers, Charles N.; Baez, Allan; Barnard, Patrick L.; Carter, James; Corsi, Alessandra; Costner, James; Cox, Dale; Das, Tapash; Dettinger, Mike; Done, James; Eadie, Charles; Eymann, Marcia; Ferris, Justin; Gunturi, Prasad; Hughes, Mimi; Jarrett, Robert; Johnson, Laurie; Le-Griffin, Hanh Dam; Mitchell, David; Morman, Suzette; Neiman, Paul; Olsen, Anna; Perry, Suzanne; Plumlee, Geoffrey; Ralph, Martin; Reynolds, David; Rose, Adam; Schaefer, Kathleen; Serakos, Julie; Siembieda, William; Stock, Jonathan; Strong, David; Wing, Ian Sue; Tang, Alex; Thomas, Pete; Topping, Ken; Wills, Chris; Jones, Lucile

2011-01-01

The U.S. Geological Survey, Multi Hazards Demonstration Project (MHDP) uses hazards science to improve resiliency of communities to natural disasters including earthquakes, tsunamis, wildfires, landslides, floods and coastal erosion. The project engages emergency planners, businesses, universities, government agencies, and others in preparing for major natural disasters. The project also helps to set research goals and provides decision-making information for loss reduction and improved resiliency. The first public product of the MHDP was the ShakeOut Earthquake Scenario published in May 2008. This detailed depiction of a hypothetical magnitude 7.8 earthquake on the San Andreas Fault in southern California served as the centerpiece of the largest earthquake drill in United States history, involving over 5,000 emergency responders and the participation of over 5.5 million citizens. This document summarizes the next major public project for MHDP, a winter storm scenario called ARkStorm (for Atmospheric River 1,000). Experts have designed a large, scientifically realistic meteorological event followed by an examination of the secondary hazards (for example, landslides and flooding), physical damages to the built environment, and social and economic consequences. The hypothetical storm depicted here would strike the U.S. West Coast and be similar to the intense California winter storms of 1861 and 1862 that left the central valley of California impassible. The storm is estimated to produce precipitation that in many places exceeds levels only experienced on average once every 500 to 1,000 years. Extensive flooding results. In many cases flooding overwhelms the state's flood-protection system, which is typically designed to resist 100- to 200-year runoffs. The Central Valley experiences hypothetical flooding 300 miles long and 20 or more miles wide. Serious flooding also occurs in Orange County, Los Angeles County, San Diego, the San Francisco Bay area, and other coastal communities. Windspeeds in some places reach 125 miles per hour, hurricane-force winds. Across wider areas of the state, winds reach 60 miles per hour. Hundreds of landslides damage roads, highways, and homes. Property damage exceeds $300 billion, most from flooding. Demand surge (an increase in labor rates and other repair costs after major natural disasters) could increase property losses by 20 percent. Agricultural losses and other costs to repair lifelines, dewater (drain) flooded islands, and repair damage from landslides, brings the total direct property loss to nearly $400 billion, of which $20 to $30 billion would be recoverable through public and commercial insurance. Power, water, sewer, and other lifelines experience damage that takes weeks or months to restore. Flooding evacuation could involve 1.5 million residents in the inland region and delta counties. Business interruption costs reach $325 billion in addition to the $400 property repair costs, meaning that an ARkStorm could cost on the order of $725 billion, which is nearly 3 times the loss deemed to be realistic by the ShakeOut authors for a severe southern California earthquake, an event with roughly the same annual occurrence probability. The ARkStorm has several public policy implications: (1) An ARkStorm raises serious questions about the ability of existing federal, state, and local disaster planning to handle a disaster of this magnitude. (2) A core policy issue raised is whether to pay now to mitigate, or pay a lot more later for recovery. (3) Innovative financing solutions are likely to be needed to avoid fiscal crisis and adequately fund response and recovery costs from a similar, real, disaster. (4) Responders and government managers at all levels could be encouraged to conduct risk assessments, and devise the full spectrum of exercises, to exercise ability of their plans to address a similar event. (5) ARkStorm can be a reference point for application of Federal Emergency Ma

New metrics for evaluating channel networks extracted in grid digital elevation models

NASA Astrophysics Data System (ADS)

Orlandini, S.; Moretti, G.

2017-12-01

Channel networks are critical components of drainage basins and delta regions. Despite the important role played by these systems in hydrology and geomorphology, there are at present no well-defined methods to evaluate numerically how two complex channel networks are geometrically far apart. The present study introduces new metrics for evaluating numerically channel networks extracted in grid digital elevation models with respect to a reference channel network (see the figure below). Streams of the evaluated network (EN) are delineated as in the Horton ordering system and examined through a priority climbing algorithm based on the triple index (ID1,ID2,ID3), where ID1 is a stream identifier that increases as the elevation of lower end of the stream increases, ID2 indicates the ID1 of the draining stream, and ID3 is the ID1 of the corresponding stream in the reference network (RN). Streams of the RN are identified by the double index (ID1,ID2). Streams of the EN are processed in the order of increasing ID1 (plots a-l in the figure below). For each processed stream of the EN, the closest stream of the RN is sought by considering all the streams of the RN sharing the same ID2. This ID2 in the RN is equal in the EN to the ID3 of the stream draining the processed stream, the one having ID1 equal to the ID2 of the processed stream. The mean stream planar distance (MSPD) and the mean stream elevation drop (MSED) are computed as the mean distance and drop, respectively, between corresponding streams. The MSPD is shown to be useful for evaluating slope direction methods and thresholds for channel initiation, whereas the MSED is shown to indicate the ability of grid coarsening strategies to retain the profiles of observed channels. The developed metrics fill a gap in the existing literature by allowing hydrologists and geomorphologists to compare descriptions of a fixed physical system obtained by using different terrain analysis methods, or different physical systems described by using the same methods.

Risk based adaptation of infrastructures to floods and storm surges induced by climate change.

NASA Astrophysics Data System (ADS)

Luna, Byron Quan; Garrè, Luca; Hansen, Peter Friis

2014-05-01

Coastal natural hazards are changing in frequency and intensity associated to climate change. These extreme events combined with an increase in the extent of vulnerable societies will lead to an increase of substantial monetary losses. For this reason, adaptive measures are required to identify the effective and adequate measures to withstand the impacts of climate change. Decision strategies are needed for the timing of investments and for the allocation of resources to safeguard the future in a sustainable manner. Adapting structures to climate change requires decision making under uncertainties. Therefore, it is vital that risk assessments are generated on a reliable and appropriate evaluation of the involved uncertainties. Linking a Bayesian network (BN) to a Geographic Information System (GIS) for a risk assessment enables to model all the relevant parameters, their causal relations and the involved uncertainties. The integration of the probabilistic approach into a GIS allows quantifying and visualizing uncertainties in a spatial manner. By addressing these uncertainties, the Bayesian Network approach allows quantifying their effects; and facilitates the identification of future model improvements and where other efforts should be concentrated. The final results can be applied as a supportive tool for presenting reliable risk assessments to decision-makers. Based on this premises, a case study was performed to assess how the storm surge magnitude and flooding extent of an event with similar characteristics to the Sandy Super storm will occur in 2050 and 2090.

The First Fermi-GBM Terrestrial Gamma Ray Flash Catalog

NASA Astrophysics Data System (ADS)

Roberts, O. J.; Fitzpatrick, G.; Stanbro, M.; McBreen, S.; Briggs, M. S.; Holzworth, R. H.; Grove, J. E.; Chekhtman, A.; Cramer, E. S.; Mailyan, B. G.

2018-05-01

We present the first Fermi Space Telescope Gamma Ray Burst Monitor (GBM) catalog of 4,144 terrestrial gamma ray flashes (TGFs), detected since launch in 11 July 2008 through 31 July 2016. We discuss the updates and improvements to the triggered data and off-line search algorithms, comparing this improved detection rate of ˜800 TGFs per year with event rates from previously published TGF catalogs from other missions. A Bayesian block algorithm calculated the temporal and spectral properties of the TGFs, revealing a delay between the hard (>300 keV) and soft (≤300 keV) photons of around 27 μs. Detector count rates of "low-fluence" events were found to have average rates exceeding 150 kHz. Searching the World-Wide Lightning Location Network data for radio sferics within ±5 min of each TGF revealed a clean sample of 1,314 World-Wide Lightning Location Network locations, which were used to to accurately locate TGF-producing storms. It also revealed lightning and storm activity for specific regions, as well as seasonal and daily variations of global lightning patterns. Correcting for the orbit of Fermi, we quantitatively find a marginal excess of TGFs being produced from storms over land near oceans (i.e., narrow isthmuses and small islands). No difference was observed between the duration of TGFs over the ocean and land. The distribution of TGFs at a given local solar time for predefined American, Asian, and African regions were confirmed to correlate well with known regional lightning rates.

Simulation of streamflow and water quality in the Red Clay Creek subbasin of the Christina River Basin, Pennsylvania and Delaware, 1994-98

USGS Publications Warehouse

Senior, Lisa A.; Koerkle, Edward H.

2003-01-01

The Christina River Basin drains 565 square miles (mi2) in Pennsylvania and Delaware and includes the major subbasins of Red Clay Creek, White Clay Creek, Brandywine Creek, and Christina River. The Red Clay Creek is the smallest of the subbasins and drains an area of 54 mi2. Streams in the Christina River Basin are used for recreation, drinking-water supply, and to support aquatic life. Water quality in some parts of the Christina River Basin is impaired and does not support designated uses of the stream. A multi-agency, waterquality management strategy included a modeling component to evaluate the effects of point and nonpointsource contributions of nutrients and suspended sediment on stream water quality. To assist in nonpointsource evaluation, four independent models, one for each of the four main subbasins of the Christina River Basin, were developed and calibrated using the model code Hydrological Simulation Program?Fortran (HSPF). Water-quality data for model calibration were collected in each of the four main subbasins and in smaller subbasins predominantly covered by one land use following a nonpoint-source monitoring plan. Under this plan, stormflow and base-flow samples were collected during 1998 at 1 site in the Red Clay Creek subbasin and at 10 sites elsewhere in the Christina River Basin.The HSPF model for the Red Clay Creek subbasin simulates streamflow, suspended sediment, and the nutrients, nitrogen and phosphorus. In addition, the model simulates water temperature, dissolved oxygen, biochemical oxygen demand, and plankton as secondary objectives needed to support the sediment and nutrient simulations. For the model, the basin was subdivided into nine reaches draining areas that ranged from 1.7 to 10 mi2. One of the reaches contains a regulated reservoir. Ten different pervious land uses and two impervious land uses were selected for simulation. Land-use areas were determined from 1995 land-use data. The predominant land uses in the Red Clay Creek subbasin are agricultural, forested, residential, and urban.The hydrologic component of the model was run at an hourly time step and calibrated using streamflow data from three U.S. Geological Survey (USGS) streamflow-measurement stations for the period of October 1, 1994, through October 29, 1998. Daily precipitation data from one National Oceanic and Atmospheric Administration (NOAA) gage and hourly data from one NOAA gage were used for model input. The difference between observed and simulated stream- flow volume ranged from -0.8 to 2.1 percent for the 4-year period at the three calibration sites. Annual differences between observed and simulated streamflow generally were greater than the overall error for the 4-year period. For example, at a site near Stanton, Del., near the bottom of the basin (drainage area of 50.2 mi2), annual differences between observed and simulated streamflow ranged from -5.8 to 6.0 percent and the overall error for the 4-year period was -0.8 percent. Calibration errors for 36 storm periods at the three calibration sites for total volume, low-flow-recession rate, 50-percent lowest flows, 10-percent highest flows, and storm peaks were 20 percent or less. Much of the error in simulating storm events on an hourly time step can be attributed to uncertainty in the rainfall data.The water-quality component of the model was calibrated using nonpoint-source monitoring data collected in 1998 at one USGS streamflowmeasurement station and other water-quality monitoring data collected at three USGS streamflowmeasurement stations. The period of record for waterquality monitoring was variable at the stations, with an end date of October 1998 but the start date ranging from October 1994 to January 1998. Because of availability, monitoring data for suspended-solids concentrations were used as surrogates for suspendedsediment concentrations, although suspended solids may underestimate suspended sediment and affect apparent accuracy of the suspended-sediment simulation. Comparison of observed to simulated loads for five storms in 1998 at the one nonpoint-source monitoring site at Wooddale, Del., indicates that simulation error commonly is as large as an order of magnitude for suspended sediment and nutrients. The simulation error tends to be smaller for dissolved utrients than particulate nutrients. Errors of 40 percent or less for monthly or annual values indicate a fair to good water-quality calibration according to recommended criteria, with much larger errors possible for individual storm events. Assessment of the accuracy of the water-quality calibration under stormflow conditions is limited by the sparsity of available water-quality data in the basin.Users of the Red Clay Creek HSPF model should be aware of model limitations and consider the following when predictive scenarios are desired: streamflow-duration curves indicate the model simulates stream-flow reasonably well when evaluated over a broad range of conditions and time, although streamflow and the corresponding water quality for individual storm events may not be well simulated; streamflow-duration curves for the simulation period compare well with duration curves for the 57.5-year period ending in 2001 at Wooddale, Del., and include all but the extreme high-flow and low-flow events; calibration for water quality was based on sparse data, with the result of increasing uncertainty in the water-quality simulation.

Semi-Autonomous Small Unmanned Aircraft Systems for Sampling Tornadic Supercell Thunderstorms

NASA Astrophysics Data System (ADS)

Elston, Jack S.

This work describes the development of a network-centric unmanned aircraft system (UAS) for in situ sampling of supercell thunderstorms. UAS have been identified as a well-suited platform for meteorological observations given their portability, endurance, and ability to mitigate atmospheric disturbances. They represent a unique tool for performing targeted sampling in regions of a supercell thunderstorm previously unreachable through other methods. Doppler radar can provide unique measurements of the wind field in and around supercell thunderstorms. In order to exploit this capability, a planner was developed that can optimize ingress trajectories for severe storm penetration. The resulting trajectories were examined to determine the feasibility of such a mission, and to optimize ingress in terms of flight time and exposure to precipitation. A network-centric architecture was developed to handle the large amount of distributed data produced during a storm sampling mission. Creation of this architecture was performed through a bottom-up design approach which reflects and enhances the interplay between networked communication and autonomous aircraft operation. The advantages of the approach are demonstrated through several field and hardware-in-the-loop experiments containing different hardware, networking protocols, and objectives. Results are provided from field experiments involving the resulting network-centric architecture. An airmass boundary was sampled in the Collaborative Colorado Nebraska Unmanned Aircraft Experiment (CoCoNUE). Utilizing lessons learned from CoCoNUE, a new concept of operations (CONOPS) and UAS were developed to perform in situ sampling of supercell thunderstorms. Deployment during the Verification of the Origins of Rotation in Tornadoes Experiment 2 (VORTEX2) resulted in the first ever sampling of the airmass associated with the rear flank downdraft of a tornadic supercell thunderstorm by a UAS. Hardware-in-the-loop simulation capability was added to the UAS to enable further assessment of the system and CONOPS. The simulation combines a full six degree-of-freedom aircraft dynamic model with wind and precipitation data from simulations of severe convective storms. Interfaces were written to involve as much of the system's field hardware as possible, including the creation of a simulated radar product server. A variety of simulations were conducted to evaluate different aspects of the CONOPS used for the 2010 VORTEX2 field campaign.

Evolution of potentially eroding events along the northern coast of the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Rasilla Álvarez, D.; García Codrón, J. C.

2009-09-01

The anthropogenic global warming is expected to result in a rise in sea-level, accompanied by changes in extreme climate events, such as the frequency and intensity of storms. Such scenario would result in an acceleration of coastal erosion. The aim of the present study is to assess the temporal evolution of potentially eroding events along the northern coast of the Iberian Peninsula during the second half of the 20th century, and to investigate changes in forcing processes such as the frequency and magnitude of storm surges and high wave events. To characterize the potentially eroding events, the total elevation of the water level was selected, being calculated as the sum of the contributions of the average water level, wave run up and the storm surges. Potentially eroding events were identified and quantified following a two-step procedure. Through the first step the potential flood induced by a given storm was estimated by simulating its effects on a theoretical beach profile (intermediate) using an empirical parameterization for extreme run-up approach. The second step consisted on characterizing the maximum storm surge registered during a storm. Those parameters were calculated from hindcasted data (storm surge, wave heights and period, wind speed and direction), retrieved from the SIMAR-44 database (Puertos del Estado), and validated against actual tide gauge measurements and buoy data (RedMar and RedExt networks). Analyses of total water levels showed a long term increase since 1958, resulting from the increase of mean sea level; conversely, a reduction of the frequency and the intensity of the storm events were deduced from the analysis of meteorological records. Since the impact of the storms on macro- and meso- tidal coast closely depend on the tides, a storm impact index was computed taking into account the storm surge magnitude, the wave heights and time duration during which a predefined threshold was exceeded by the sea level. The results are consistent with the analysis of the shoreline evolution on a specific sector of Cantabria (Oyambre) through the comparison of aerial photographs taken between 1957 and 2005. From the late 50´s to late 70’s, the shoreline significantly retreated, in correspondence with the period of maximum storm activity. Conversely, shoreline retreat slowed down during the late 1980s and 1990s while storm activity considerably decreased. Thus long-term coastal erosion, due to the occurrences of high water levels embedded into a long trend term of sea level rise, has been balanced by the reduction of the frequency and intensity of the Atlantic storms. Since relative sea-level will continue rising in the future, most of the coastal morphologies will probably be more frequently reached by the sea, increasing the flooding risk in low-lying sectors and promoting landslides along the cliffs.

The Portals 4.0 network programming interface.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barrett, Brian W.; Brightwell, Ronald Brian; Pedretti, Kevin

2012-11-01

This report presents a specification for the Portals 4.0 network programming interface. Portals 4.0 is intended to allow scalable, high-performance network communication between nodes of a parallel computing system. Portals 4.0 is well suited to massively parallel processing and embedded systems. Portals 4.0 represents an adaption of the data movement layer developed for massively parallel processing platforms, such as the 4500-node Intel TeraFLOPS machine. Sandias Cplant cluster project motivated the development of Version 3.0, which was later extended to Version 3.3 as part of the Cray Red Storm machine and XT line. Version 4.0 is targeted to the next generationmore » of machines employing advanced network interface architectures that support enhanced offload capabilities.« less

Understanding Flash Flood Generation in the Arid Region of the Dead Sea

NASA Astrophysics Data System (ADS)

Merz, R.; Hennig, H.; Rödiger, T.; Laronne, J. B.

2017-12-01

The arid region of the Dead Sea is prone by flash floods. Such flash floods in (semi-) arid regions are impressive. Generated within minutes, the peak unit discharge can be as high as 25 m³/s km². Floods are the main mechanism supplying water to alluvial aquifers, forming fluvial landscapes including canyons and often causing damage to humans, infrastructure, industry and tourism. Existing hydrological models in this region focus on peak discharges. However, these models are often based on simplified concepts and/or on concepts which were developed for humid regions. To more closely relate such models to local conditions, processes within catchments where floods occur require consideration. Therefore, a measurement network of rain gauges and level loggers to monitor runoff was installed in the beginning of the 2015/16 hydrological season in the tributaries of Wadi Arugot. The Arugot catchment is one of the largest ephemeral Wadis draining to the western shoreline of the Dead Sea at 450 m bsl. Due to the high gradient in elevation, the climate within the basin ranges from semiarid in the Judean Mountains, to hyper-arid near the Dead Sea with respective mean annual rainfall of 650 and 50 mm. The installed rain gauge network in the mountains is more dense compared to the Dead Sea area. Arid to semiarid catchments have different runoff generation processes compared to humid regions due local storm rainfall, low density of vegetation cover as well as patchy and shallow soil. These characteristics limit the contribution of groundwater flow, saturated overland flow and shallow subsurface flow, and therefore Hortonian overland flow is the most important contributor to overland flow. First analyses of the runoff data have shown that the storage capacity in the mountain area is lower compared to the more arid region. This is an evidence of high transmission losses in the coarse gravel wadi bed, therefore having a high permeability. The rain event duration and the amount of rain could not be determined as the only factors which lead to the generation of runoff events.

Geomorphic effects of large debris flows and flash floods, northern Venezuela, 1999

USGS Publications Warehouse

Larsen, M.C.; Wieczorek, G.F.

2006-01-01

A rare, high-magnitude storm in northern Venezuela in December 1999 triggered debris flows and flash floods, and caused one of the worst natural disasters in the recorded history of the Americas. Some 15,000 people were killed. The debris flows and floods inundated coastal communities on alluvial fans at the mouths of a coastal mountain drainage network and destroyed property estimated at more than $2 billion. Landslides were abundant and widespread on steep slopes within areas underlain by schist and gneiss from near the coast to slightly over the crest of the mountain range. Some hillsides were entirely denuded by single or coalescing failures, which formed massive debris flows in river channels flowing out onto densely populated alluvial fans at the coast. The massive amount of sediment derived from 24 watersheds along 50 km of the coast during the storm and deposited on alluvial fans and beaches has been estimated at 15 to 20 million m3. Sediment yield for the 1999 storm from the approximately 200 km2 drainage area of watersheds upstream of the alluvial fans was as much as 100,000 m3/km2. Rapid economic development in this dynamic geomorphic environment close to the capital city of Caracas, in combination with a severe rain storm, resulted in the death of approximately 5% of the population (300,000 total prior to the storm) in the northern Venezuelan state of Vargas. ?? 2006 Gebru??der Borntraeger.

Radio Emissions from Electrical Activity in Martian Dust Storms

NASA Astrophysics Data System (ADS)

Majid, W.; Arabshahi, S.; Kocz, J.; Schulter, T.; White, L.

2017-12-01

Dust storms on Mars are predicted to be capable of producing electrostatic fields and discharges, even larger than those in dust storms on Earth. There are three key elements in the characterization of Martian electrostatic discharges: dependence on Martian environmental conditions, event rate, and the strength of the generated electric fields. The detection and characterization of electric activity in Martian dust storms has important implications for habitability, and preparations for human exploration of the red planet. Furthermore, electrostatic discharges may be linked to local chemistry and plays an important role in the predicted global electrical circuit. Because of the continuous Mars telecommunication needs of NASA's Mars-based assets, the Deep Space Network (DSN) is the only facility in the world that combines long term, high cadence, observing opportunities with large sensitive telescopes, making it a unique asset worldwide in searching for and characterizing electrostatic activity from large scale convective dust storms at Mars. We will describe a newly inaugurated program at NASA's Madrid Deep Space Communication Complex to carry out a long-term monitoring campaign to search for and characterize the entire Mars hemisphere for powerful discharges during routine tracking of spacecraft at Mars on an entirely non-interfering basis. The ground-based detections will also have important implications for the design of a future instrument that could make similar in-situ measurements from orbit or from the surface of Mars, with far greater sensitivity and duty cycle, opening up a new window in our understanding of the Martian environment.

Navigating the storm: report and recommendations from the Atlantic Storm exercise.

PubMed

Smith, Bradley T; Inglesby, Thomas V; Brimmer, Esther; Borio, Luciana; Franco, Crystal; Gronvall, Gigi Kwik; Kramer, Bradley; Maldin, Beth; Nuzzo, Jennifer B; Schuler, Ari; Stern, Scott; Henderson, Donald A; Larsen, Randall J; Hamilton, Daniel S; O'Toole, Tara

2005-01-01

Atlantic Storm was a tabletop exercise simulating a series of bioterrorism attacks on the transatlantic community. The exercise occurred on January 14, 2005, in Washington, DC, and was organized and convened by the Center for Biosecurity of UPMC, the Center for Transatlantic Relations of Johns Hopkins University, and the Transatlantic Biosecurity Network. Atlantic Storm portrayed a summit meeting of presidents, prime ministers, and other international leaders from both sides of the Atlantic Ocean in which they responded to a campaign of bioterrorist attacks in several countries. The summit principals, who were all current or former senior government leaders, were challenged to address issues such as attaining situational awareness in the wake of a bioattack, coping with scarcity of critical medical resources such as vaccine, deciding how to manage the movement of people across borders, and communicating with their publics. Atlantic Storm illustrated that much might be done in advance to minimize the illness and death, as well as the social, economic, and political disruption, that could be caused by an international epidemic, be it natural or the result of a bioterrorist attack. These lessons are especially timely given the growing concerns over the possibility of an avian influenza pandemic that would require an international response. However, international leaders cannot create the necessary response systems in the midst of a crisis. Medical, public health, and diplomatic response systems and critical medical resources (e.g., medicines and vaccines) must be in place before a bioattack occurs or a pandemic emerges.

The impact of agricultural land use on stream chemistry in the Middle Hills of the Himalayas, Nepal

NASA Astrophysics Data System (ADS)

Collins, Robert; Jenkins, Alan

1996-11-01

The chemistry of streams draining agricultural and forested catchments in the Middle Hills of Nepal is described. Differences between mean streamwater chemistry are attributable to the effects of the terraced agriculture and land management practices. The agricultural catchments were found to exhibit higher mean concentrations of base cations (Na, Mg, K), bicarbonate, acid anions (SO 4, Cl), metals (Al, Fe) and nutrients (NO 3, PO 4). Increased base cations apparently result from tillage practices exposing fresh soil material to weathering. Increased acid anions result from inputs of inorganic fertiliser, notably ammonium sulphate, and from an apparent increase in evapotranspiration from the flooded terraces in the agricultural catchments. Increased metal concentrations may be promoted by increased weathering and erosion rates, and this is further supported by observations of dramatically higher turbidity in the streamwater draining the agricultural catchments. Higher levels of nutrients are the direct result of fertiliser input but concentrations are generally low from all catchments as a result of denitrification, indicating that eutrophication downstream is not a likely consequence of land use change. The major dynamics of water chemistry occur during the monsoon, which is also the main season for agricultural production. Mean wet season concentrations of base cations tend to be lower than in the dry season at all catchments as higher flow dilutes the relatively constant weathering input. Ammonium concentrations are higher from the agricultural catchments in the wet season as a result of direct washout of fertiliser. Detailed monitoring through storm periods at one agricultural catchment indicates that the chemistry responds very rapidly to changing flow, with cations decreasing and acid anions increasing followed by equally rapid recovery as flow recedes. Bicarbonate concentrations also decline markedly but are still sufficiently high to maintain pH near neutral throughout the storm event. The impacts of agricultural land use on streamwater chemistry are unlikely to lead to potentially damaging consequences for the aquatic biota at present or in the short-term future. The potential for acidity generation as a result of the high loads of nitrogenous fertilisers applied is apparently buffered by the land tillage practices, which promote higher weathering and so higher concentrations of base cations.

The role of precipitation type, intensity, and spatial distribution in source water quality after wildfire

NASA Astrophysics Data System (ADS)

Murphy, Sheila F.; Writer, Jeffrey H.; Blaine McCleskey, R.; Martin, Deborah A.

2015-08-01

Storms following wildfires are known to impair drinking water supplies in the southwestern United States, yet our understanding of the role of precipitation in post-wildfire water quality is far from complete. We quantitatively assessed water-quality impacts of different hydrologic events in the Colorado Front Range and found that for a three-year period, substantial hydrologic and geochemical responses downstream of a burned area were primarily driven by convective storms with a 30 min rainfall intensity >10 mm h-1. These storms, which typically occur several times each year in July-September, are often small in area, short-lived, and highly variable in intensity and geographic distribution. Thus, a rain gage network with high temporal resolution and spatial density, together with high-resolution stream sampling, are required to adequately characterize post-wildfire responses. We measured total suspended sediment, dissolved organic carbon (DOC), nitrate, and manganese concentrations that were 10-156 times higher downstream of a burned area compared to upstream during relatively common (50% annual exceedance probability) rainstorms, and water quality was sufficiently impaired to pose water-treatment concerns. Short-term water-quality impairment was driven primarily by increased surface runoff during higher intensity convective storms that caused erosion in the burned area and transport of sediment and chemical constituents to streams. Annual sediment yields downstream of the burned area were controlled by storm events and subsequent remobilization, whereas DOC yields were closely linked to annual runoff and thus were more dependent on interannual variation in spring runoff. Nitrate yields were highest in the third year post-wildfire. Results from this study quantitatively demonstrate that water quality can be altered for several years after wildfire. Because the southwestern US is prone to wildfires and high-intensity rain storms, the role of storms in post-wildfire water-quality impacts must be considered when assessing water-quality vulnerability.

Response of the Mississippi Bight and Sound to the Passage of Tropical Storm Cindy Through the Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Hode, L. E.; Howden, S. D.; Diercks, A. R.; Cambazoglu, M. K.; Jones, E. B.; Martin, K. M.

2017-12-01

Damage inflicted by tropical storms and hurricanes on coastal communities and industries has become a growing concern in recent decades. Consequently, utilizing products from existing ocean observing platforms, ocean modeling forecasts and satellite data helps to identify the effects of individual storms on the northern Gulf of Mexico. Using data from the jointly-operated United States Geological Survey and Mississippi Department of Marine Resources (USGS-MDMR) hydrological stations, National Oceanic and Atmospheric Administration (NOAA) tide gages, and the Central Gulf of Mexico Ocean Observing System (CenGOOS) high frequency radar (HFR) network, we tracked temperature, salinity, water level and surface current changes in the Mississippi Sound and Bight during June 2017. We performed time series analyses and compared conditions during the buildup and passage of tropical storm Cindy to climatological values as well as to satellite observations and results from a regional application of the Navy Coastal Ocean Model (NCOM). Elevated salinities proceeded Cindy's landfall on June 22, 2017, while anomalously fresh water marked all Mississippi Sound stations afterwards. Onshore surface currents dominated the Mississippi Bight, and current speeds exceeded more than four times the climatological average in the southeastern Bight. Indeed, regions of enhanced current speeds were observed throughout the month of June 2017. Tidal ranges in the Mississippi Sound were on average half a meter higher than predicted, and Shell Beach (Louisiana) and the Bay Waveland Yacht Club (Mississippi) saw extended periods where tides exceeded one meter above predicted values. These results help to quantify the tidal inundation caused by Cindy but also illustrate the massive riverine discharge driven by the storm's precipitation. Model results provide information on areas of the study region not covered by measurements; additionally, comparing observations to model products helps estimate model effectiveness for storm events. Though Cindy never became a hurricane, the storm caused extensive and widespread coastal flooding, strong surface currents and salinity fluctuations in the northern Gulf of Mexico.

The role of precipitation type, intensity, and spatial distribution in source water quality after wildfire

USGS Publications Warehouse

Murphy, Sheila F.; Writer, Jeffrey H.; McCleskey, R. Blaine; Martin, Deborah A.

2015-01-01

Storms following wildfires are known to impair drinking water supplies in the southwestern United States, yet our understanding of the role of precipitation in post-wildfire water quality is far from complete. We quantitatively assessed water-quality impacts of different hydrologic events in the Colorado Front Range and found that for a three-year period, substantial hydrologic and geochemical responses downstream of a burned area were primarily driven by convective storms with a 30 min rainfall intensity >10 mm h−1. These storms, which typically occur several times each year in July–September, are often small in area, short-lived, and highly variable in intensity and geographic distribution. Thus, a rain gage network with high temporal resolution and spatial density, together with high-resolution stream sampling, are required to adequately characterize post-wildfire responses. We measured total suspended sediment, dissolved organic carbon (DOC), nitrate, and manganese concentrations that were 10–156 times higher downstream of a burned area compared to upstream during relatively common (50% annual exceedance probability) rainstorms, and water quality was sufficiently impaired to pose water-treatment concerns. Short-term water-quality impairment was driven primarily by increased surface runoff during higher intensity convective storms that caused erosion in the burned area and transport of sediment and chemical constituents to streams. Annual sediment yields downstream of the burned area were controlled by storm events and subsequent remobilization, whereas DOC yields were closely linked to annual runoff and thus were more dependent on interannual variation in spring runoff. Nitrate yields were highest in the third year post-wildfire. Results from this study quantitatively demonstrate that water quality can be altered for several years after wildfire. Because the southwestern US is prone to wildfires and high-intensity rain storms, the role of storms in post-wildfire water-quality impacts must be considered when assessing water-quality vulnerability.

Comprehensive Analysis of the Geoeffective Solar Event of 21 June 2015: Effects on the Magnetosphere, Plasmasphere, and Ionosphere Systems

NASA Astrophysics Data System (ADS)

Piersanti, Mirko; Alberti, Tommaso; Bemporad, Alessandro; Berrilli, Francesco; Bruno, Roberto; Capparelli, Vincenzo; Carbone, Vincenzo; Cesaroni, Claudio; Consolini, Giuseppe; Cristaldi, Alice; Del Corpo, Alfredo; Del Moro, Dario; Di Matteo, Simone; Ermolli, Ilaria; Fineschi, Silvano; Giannattasio, Fabio; Giorgi, Fabrizio; Giovannelli, Luca; Guglielmino, Salvatore Luigi; Laurenza, Monica; Lepreti, Fabio; Marcucci, Maria Federica; Martucci, Matteo; Mergè, Matteo; Pezzopane, Michael; Pietropaolo, Ermanno; Romano, Paolo; Sparvoli, Roberta; Spogli, Luca; Stangalini, Marco; Vecchio, Antonio; Vellante, Massimo; Villante, Umberto; Zuccarello, Francesca; Heilig, Balázs; Reda, Jan; Lichtenberger, János

2017-11-01

A full-halo coronal mass ejection (CME) left the Sun on 21 June 2015 from active region (AR) NOAA 12371. It encountered Earth on 22 June 2015 and generated a strong geomagnetic storm whose minimum Dst value was -204 nT. The CME was associated with an M2-class flare observed at 01:42 UT, located near disk center (N12 E16). Using satellite data from solar, heliospheric, and magnetospheric missions and ground-based instruments, we performed a comprehensive Sun-to-Earth analysis. In particular, we analyzed the active region evolution using ground-based and satellite instruments (Big Bear Solar Observatory (BBSO), Interface Region Imaging Spectrograph (IRIS), Hinode, Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO), Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), covering Hα, EUV, UV, and X-ray data); the AR magnetograms, using data from SDO/ Helioseismic and Magnetic Imager (HMI); the high-energy particle data, using the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instrument; and the Rome neutron monitor measurements to assess the effects of the interplanetary perturbation on cosmic-ray intensity. We also evaluated the 1 - 8 Å soft X-ray data and the {˜} 1 MHz type III radio burst time-integrated intensity (or fluence) of the flare in order to predict the associated solar energetic particle (SEP) event using the model developed by Laurenza et al. ( Space Weather 7(4), 2009). In addition, using ground-based observations from lower to higher latitudes ( International Real-time Magnetic Observatory Network (INTERMAGNET) and European Quasi-Meridional Magnetometer Array (EMMA)), we reconstructed the ionospheric current system associated with the geomagnetic sudden impulse (SI). Furthermore, Super Dual Auroral Radar Network (SuperDARN) measurements were used to image the global ionospheric polar convection during the SI and during the principal phases of the geomagnetic storm. In addition, to investigate the influence of the disturbed electric field on the low-latitude ionosphere induced by geomagnetic storms, we focused on the morphology of the crests of the equatorial ionospheric anomaly by the simultaneous use of the Global Navigation Satellite System (GNSS) receivers, ionosondes, and Langmuir probes onboard the Swarm constellation satellites. Moreover, we investigated the dynamics of the plasmasphere during the different phases of the geomagnetic storm by examining the time evolution of the radial profiles of the equatorial plasma mass density derived from field line resonances detected at the EMMA network (1.5 < L < 6.5). Finally, we present the general features of the geomagnetic response to the CME by applying innovative data analysis tools that allow us to investigate the time variation of ground-based observations of the Earth's magnetic field during the associated geomagnetic storm.

Concentration-Discharge Behavior of Contaminants in a Stream Impacted by Acid Mine Drainage

NASA Astrophysics Data System (ADS)

Shaw, M. E.; Klein, M.; Herndon, E.

2017-12-01

Acid mine drainage (AMD) has severely degraded streams throughout the Appalachian coal region of the United States. AMD occurs when pyrite contained in coal is exposed to water and air during mining activities and oxidized to release high concentrations of sulfate, metals, and acidity into water bodies. Little is known about the concentration-discharge (CQ) relationships of solutes in AMD-impacted streams due to the complicated nature of acid mine drainage systems. For example, streams may receive inputs from multiple sources that include runoff, constructed treatment systems, and abandoned mines that bypass these systems to continue to contaminate the streams. It is important to understand the CQ relationships of contaminants in AMD-impacted streams in order to elucidate contaminant sources and to predict effects on aquatic ecosystems. Here, we study the CQ behaviors of acid and metals in a contaminated watershed in northeastern Ohio where limestone channels have been installed to remediate water draining from a mine pool into the stream. Stream chemistry was measured in samples collected once per day or once per hour during storm events, and stream flow was measured continuously at the watershed outlet. Increases in stream velocity during storm events resulted in an increase in pH (from 3 to 6) that subsequently decreased back to 3 as flow decreased. Additionally, Fe and Mn concentrations in the stream were high during baseflow (7 and 15 mg/L, respectively) and decreased with increasing discharge during storm events. These results indicate that the treatment system is only effective at neutralizing stream acidity and removing metals when water flow through the limestone channel is continuous. We infer that the acidic and metal-rich baseflow derives from upwelling of contaminated groundwater or subsurface flow from a mine pool. Ongoing studies aim to isolate the source of this baseflow contamination and evaluate the geochemical transformations that occur as it flows into the stream.