Corrosive microenvironments at lead solder surfaces arising from galvanic corrosion with copper pipe.

PubMed

Nguyen, Caroline K; Stone, Kendall R; Dudi, Abhijeet; Edwards, Marc A

2010-09-15

As stagnant water contacts copper pipe and lead solder (simulated soldered joints), a corrosion cell is formed between the metals in solder (Pb, Sn) and the copper. If the resulting galvanic current exceeds about 2 μA/cm(2), a highly corrosive microenvironment can form at the solder surface, with pH < 2.5 and chloride concentrations at least 11 times higher than bulk water levels. Waters with relatively high chloride tend to sustain high galvanic currents, preventing passivation of the solder surface, and contributing to lead contamination of potable water supplies. The total mass of lead corroded was consistent with predictions based on the galvanic current, and lead leaching to water was correlated with galvanic current. If the concentration of sulfate in the water increased relative to chloride, galvanic currents and associated lead contamination could be greatly reduced, and solder surfaces were readily passivated.

A Review of Nitrates in Drinking Water: Maternal Exposure and Adverse Reproductive and Developmental Outcomes

PubMed Central

Manassaram, Deana M.; Backer, Lorraine C.; Moll, Deborah M.

2006-01-01

In this review we present an update on maternal exposure to nitrates in drinking water in relation to possible adverse reproductive and developmental effects, and also discuss nitrates in drinking water in the United States. The current standard for nitrates in drinking water is based on retrospective studies and approximates a level that protects infants from methemoglobinemia, but no safety factor is built into the standard. The current standard applies only to public water systems. Drinking water source was related to nitrate exposure (i.e., private systems water was more likely than community system water to have nitrate levels above the maximum contaminant limit). Animal studies have found adverse reproductive effects resulting from higher doses of nitrate or nitrite. The epidemiologic evidence of a direct exposure–response relationship between drinking water nitrate level and adverse reproductive effect is still not clear. However, some reports have suggested an association between exposure to nitrates in drinking water and spontaneous abortions, intrauterine growth restriction, and various birth defects. Uncertainties in epidemiologic studies include the lack of individual exposure assessment that would rule out confounding of the exposure with some other cause. Nitrates may be just one of the contaminants in drinking water contributing to adverse outcomes. We conclude that the current literature does not provide sufficient evidence of a causal relationship between exposure to nitrates in drinking water and adverse reproductive effects. Future studies incorporating individual exposure assessment about users of private wells—the population most at risk—should be considered. PMID:16507452

Water transparency distribution under varied currents in the largest river-connected lake of China.

PubMed

Wang, Hua; Zhao, Yijun; Zhang, Zhizhang; Pang, Yong; Liang, Dongfang

2017-01-01

Water transparency is an important ecological indicator for shallow lakes. The largest shallow lake, Poyang Lake, as well as the most typical river-connected lake in China was selected as the research area. In view of the complicated water-sediment conditions induced by its frequent water exchange with external rivers, the dominant factors driving water transparency were determined against the field investigated data from 2003 to 2013 and a specific driving function was established. A numerical model coupling suspended sediment, Chl-a and chemical oxygen demand was developed and validated, and the spatial water transparency distributions under three typical current structures in Poyang Lake, Gravity-style, Jacking-style and Backflow-style, were quantitatively estimated. The following results stood out: water transparency in the lake varied distinctly with the current status; Backflow-style current was basically characterized by the lowest water transparency, while that under Jacking-style was the highest due to the lower sediment carrying capacity. In some outlying regions in the lake, where the water current is hardly influenced by the mainstream, the water transparency was always kept at a stable level.

A practical tool for estimating subsurface LNAPL distributions and transmissivity using current and historical fluid levels in groundwater wells: Effects of entrapped and residual LNAPL

NASA Astrophysics Data System (ADS)

Lenhard, R. J.; Rayner, J. L.; Davis, G. B.

2017-10-01

A model is presented to account for elevation-dependent residual and entrapped LNAPL above and below, respectively, the water-saturated zone when predicting subsurface LNAPL specific volume (fluid volume per unit area) and transmissivity from current and historic fluid levels in wells. Physically-based free, residual, and entrapped LNAPL saturation distributions and LNAPL relative permeabilities are integrated over a vertical slice of the subsurface to yield the LNAPL specific volumes and transmissivity. The model accounts for effects of fluctuating water tables. Hypothetical predictions are given for different porous media (loamy sand and clay loam), fluid levels in wells, and historic water-table fluctuations. It is shown the elevation range from the LNAPL-water interface in a well to the upper elevation where the free LNAPL saturation approaches zero is the same for a given LNAPL thickness in a well regardless of porous media type. Further, the LNAPL transmissivity is largely dependent on current fluid levels in wells and not historic levels. Results from the model can aid developing successful LNAPL remediation strategies and improving the design and operation of remedial activities. Results of the model also can aid in accessing the LNAPL recovery technology endpoint, based on the predicted transmissivity.

EXTRACTION AND DETERMINATION OF ARSENICALS FOUND IN FISH TISSUE

EPA Science Inventory

Arsenic in Drinking Water is regulated under the Safe Drinking Water Act. The maximum contaminant level (MCL) for arsenic is currently 50ppb. The USEPA is currently under a court order to revise the arsenic regulation by the year 2000. One aspect which requires some considerat...

SPRINGFIELD SURFACE WATER ACTION MONITORING PARTNERSHIP(SSWAMP)

EPA Science Inventory

The objectives of this project are as follows: 1) To determine the baseline chemical and biological characteristics of the water bodies and to determine the baseline levels of nutrients, metals and organic contaminants in the sediments. To determine the current level of mercur...

Improving the Predictability of Severe Water Levels along the Coasts of Marginal Seas

NASA Astrophysics Data System (ADS)

Ridder, N. N.; de Vries, H.; van den Brink, H.; De Vries, H.

2016-12-01

Extreme water levels can lead to catastrophic consequences with severe societal and economic repercussions. Particularly vulnerable are countries that are largely situated below sea level. To support and optimize forecast models, as well as future adaptation efforts, this study assesses the modeled contribution of storm surges and astronomical tides to total water levels under different air-sea momentum transfer parameterizations in a numerical surge model (WAQUA/DCSMv5) of the North Sea. It particularly focuses on the implications for the representation of extreme and rapidly recurring severe water levels over the past decades based on the example of the Netherlands. For this, WAQUA/DCSMv5, which is currently used to forecast coastal water levels in the Netherlands, is forced with ERA Interim reanalysis data. Model results are obtained from two different methodologies to parameterize air-sea momentum transfer. The first calculates the governing wind stress forcing using a drag coefficient derived from the conventional approach of wind speed dependent Charnock constants. The other uses instantaneous wind stress from the parameterization of the quasi-linear theory applied within the ECMWF wave model which is expected to deliver a more realistic forcing. The performance of both methods is tested by validating the model output with observations, paying particular attention to their ability to reproduce rapidly succeeding high water levels and extreme events. In a second step, the common features of and connections between these events are analyzed. The results of this study will allow recommendations for the improvement of water level forecasts within marginal seas and support decisions by policy makers. Furthermore, they will strengthen the general understanding of severe and extreme water levels as a whole and help to extend the currently limited knowledge about clustering events.

Future groundwater extraction scenarios for an aquifer in a semiarid environment: case study of Guadalupe Valley Aquifer, Baja California, Northwest Mexico.

PubMed

Campos-Gaytan, Jose Ruben; Kretzschmar, Thomas; Herrera-Oliva, Claudia Soledad

2014-11-01

Semiarid northwestern Mexico presents a growing water demand produced by agricultural and domestic requirements during the last two decades. The community of Guadalupe Valley and the city of Ensenada rely on groundwater pumping from the local aquifer as its sole source of water supply. This dependency has resulted in an imbalance between groundwater pumpage and natural recharge. A two-dimensional groundwater flow model was applied to the Guadalupe Valley Aquifer, which was calibrated and validated for the period 1984-2005. The model analysis verified that groundwater levels in the region are subject to steep declines due to decades of intensive groundwater exploitation for agricultural and domestic purposes. The calibrated model was used to assess the effects of different water management scenarios for the period 2007-2025. If the base case (status quo) scenario continues, groundwater levels are in a continuous drawdown trend. Some wells would run dry by August 2017, and water demand may not be met without incurring in an overdraft. The optimistic scenario implies the achievement of the mean groundwater recharge and discharge. Groundwater level depletion could be stopped and restored. The sustainable scenario implies the reduction of current extraction (up to about 50 %), when groundwater level depletion could be stopped. A reduction in current extraction mitigates water stress in the aquifer but cannot solely reverse declining water tables across the region. The combination of reduced current extraction and an implemented alternative solution (such as groundwater artificial recharge), provides the most effective measure to stabilize and reverse declining groundwater levels while meeting water demands in the region.

Future land-use related water demand in California

USGS Publications Warehouse

Wilson, Tamara; Sleeter, Benjamin M.; Cameron, D. Richard

2016-01-01

Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use restrictions. Increases in population and land use in coming decades will place additional pressure on already limited available water supplies. We used a state-and-transition simulation model to project future changes in developed (municipal and industrial) and agricultural land use to estimate associated water use demand from 2012 to 2062. Under current efficiency rates, total water use was projected to increase 1.8 billion cubic meters(+4.1%) driven primarily by urbanization and shifts to more water intensive crops. Only if currently mandated 25% reductions in municipal water use are continuously implemented would water demand in 2062 balance to water use levels in 2012. This is the first modeling effort of its kind to examine regional land-use related water demand incorporating historical trends of both developed and agricultural land uses.

Analysis of ground-water data for selected wells near Holloman Air Force Base, New Mexico, 1950-95

USGS Publications Warehouse

Huff, G.F.

1996-01-01

Ground-water-level, ground-water-withdrawal, and ground- water-quality data were evaluated for trends. Holloman Air Force Base is located in the west-central part of Otero County, New Mexico. Ground-water-data analyses include assembly and inspection of U.S. Geological Survey and Holloman Air Force Base data, including ground-water-level data for public-supply and observation wells and withdrawal and water-quality data for public-supply wells in the area. Well Douglas 4 shows a statistically significant decreasing trend in water levels for 1972-86 and a statistically significant increasing trend in water levels for 1986-90. Water levels in wells San Andres 5 and San Andres 6 show statistically significant decreasing trends for 1972-93 and 1981-89, respectively. A mixture of statistically significant increasing trends, statistically significant decreasing trends, and lack of statistically significant trends over periods ranging from the early 1970's to the early 1990's are indicated for the Boles wells and wells near the Boles wells. Well Boles 5 shows a statistically significant increasing trend in water levels for 1981-90. Well Boles 5 and well 17S.09E.25.343 show no statistically significant trends in water levels for 1990-93 and 1988-93, respectively. For 1986-93, well Frenchy 1 shows a statistically significant decreasing trend in water levels. Ground-water withdrawal from the San Andres and Douglas wells regularly exceeded estimated ground-water recharge from San Andres Canyon for 1963-87. For 1951-57 and 1960-86, ground-water withdrawal from the Boles wells regularly exceeded total estimated ground-water recharge from Mule, Arrow, and Lead Canyons. Ground-water withdrawal from the San Andres and Douglas wells and from the Boles wells nearly equaled estimated ground- water recharge for 1989-93 and 1986-93, respectively. For 1987- 93, ground-water withdrawal from the Escondido well regularly exceeded estimated ground-water recharge from Escondido Canyon, and ground-water withdrawal from the Frenchy wells regularly exceeded total estimated ground-water recharge from Dog and Deadman Canyons. Water-quality samples were collected from selected Douglas, San Andres, and Boles public-supply wells from December 1994 to February 1995. Concentrations of dissolved nitrate show the most consistent increases between current and historical data. Current concentrations of dissolved nitrate are greater than historical concentrations in 7 of 10 wells.

Nitrate in drinking water and colorectal cancer risk: A nationwide population-based cohort study.

PubMed

Schullehner, Jörg; Hansen, Birgitte; Thygesen, Malene; Pedersen, Carsten B; Sigsgaard, Torben

2018-07-01

Nitrate in drinking water may increase risk of colorectal cancer due to endogenous transformation into carcinogenic N-nitroso compounds. Epidemiological studies are few and often challenged by their limited ability of estimating long-term exposure on a detailed individual level. We exploited population-based health register data, linked in time and space with longitudinal drinking water quality data, on an individual level to study the association between long-term drinking water nitrate exposure and colorectal cancer (CRC) risk. Individual nitrate exposure was calculated for 2.7 million adults based on drinking water quality analyses at public waterworks and private wells between 1978 and 2011. For the main analyses, 1.7 million individuals with highest exposure assessment quality were included. Follow-up started at age 35. We identified 5,944 incident CRC cases during 23 million person-years at risk. We used Cox proportional hazards models to estimate hazard ratios (HRs) of nitrate exposure on the risk of CRC, colon and rectal cancer. Persons exposed to the highest level of drinking water nitrate had an HR of 1.16 (95% CI: 1.08-1.25) for CRC compared with persons exposed to the lowest level. We found statistically significant increased risks at drinking water levels above 3.87 mg/L, well below the current drinking water standard of 50 mg/L. Our results add to the existing evidence suggesting increased CRC risk at drinking water nitrate concentrations below the current drinking water standard. A discussion on the adequacy of the drinking water standard in regards to chronic effects is warranted. © 2018 UICC.

Effects of climate and socio-economic changes on water availability, use and management at the regional scale - a case study in the dry inner-alpine zone of Switzerland

NASA Astrophysics Data System (ADS)

Weingartner, Rolf; Reynard, Emmanuel; Graefe, Olivier; Liniger, Hanspeter; Rist, Stephan; Schaedler, Bruno; Schneider, Flurina

2014-05-01

The research program NRP 61 "Sustainable Water Management" of the Swiss National Science Foundation had set the goal to provide a basis for sustainable water management in Switzerland. As part of this research program the effects of climate and socio-economic changes on water availability, water use and water management were investigated in the Crans-Montana-Sierre region, situated in the dry inner-alpine Valais (project MontanAqua). The project followed an inter- and trans-disciplinary approach; stakeholders were involved from the very beginning. We assessed the current water situation with quantitative and qualitative methods: A dense hydro-meteorological network was built-up, tracer experiments were conducted and communal water uses as well as the current water management system were analyzed. These investigations paved the way to develop models to simulate possible changes in the near and far future. For this purpose, we applied existing regional climate change scenarios and developed socio-economic scenarios together with the stakeholders. The findings of MontanAqua can be summarized into five messages, each with a short recommendation: 1 - The socio-economic changes have a greater impact on the water situation in 2050 than climate change: A territorial development that limits water needs is recommended. This requires important changes of current water- and land-management practices. 2 - The water quantities available now and in 2050 are generally sufficient. However, shortages are possible in some areas and seasonally: We recommend establishing a regional water management which goes beyond the development of technical infrastructure such as storage facilities or connections between water supply networks. This measure should be accompanied by a clarification and negotiation of water rights at the regional level. 3 - Water issues are primarily regional management problems: We advocate for better cooperation between the eleven municipalities of the region and the establishment of a demand management strategy which is aimed at coordinating uses and reducing water needs. 4 - Inter-communal measures on infrastructures can help to ensure sustainable water supply, but only if they are integrated into ambitious institutional reforms: A more equitable water management at the regional level requires a new negotiation of management principles and access rights to the water resources. 5 - To achieve a sustainable regional water management, improved data management and transparency is needed: We recommend that the Valais Canton develop a strategy for monitoring water at the regional level and for the collection of homogenized data. We also recommend that the Canton assess the current water management at the regional level in terms of sustainability. Finally, we advocate that a study to clarify the water rights is launched.

7 CFR 1806.23 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels, or abnormally high tidal water or rising coastal waters resulting from severe storms, hurricanes, or tidal waves resulting from volcano eruptions or earthquakes. (g) Mudslide or...

7 CFR 1806.23 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels, or abnormally high tidal water or rising coastal waters resulting from severe storms, hurricanes, or tidal waves resulting from volcano eruptions or earthquakes. (g) Mudslide or...

7 CFR 1806.23 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels, or abnormally high tidal water or rising coastal waters resulting from severe storms, hurricanes, or tidal waves resulting from volcano eruptions or earthquakes. (g) Mudslide or...

7 CFR 1806.23 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels, or abnormally high tidal water or rising coastal waters resulting from severe storms, hurricanes, or tidal waves resulting from volcano eruptions or earthquakes. (g) Mudslide or...

7 CFR 1806.23 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels, or abnormally high tidal water or rising coastal waters resulting from severe storms, hurricanes, or tidal waves resulting from volcano eruptions or earthquakes. (g) Mudslide or...

Georgia's Ground-Water Resources and Monitoring Network, 2006

USGS Publications Warehouse

Nobles, Patricia L.

2006-01-01

The U.S. Geological Survey (USGS) ground-water network for Georgia currently consists of 170 wells in which ground-water levels are continuously monitored. Most of the wells are locatedin the Coastal Plain in the southern part of the State where ground-water pumping stress is high. In particular, there are large concentrations of wells in coastal and southwestern Georgia areas, where there are issues related to ground-water pumping, saltwater intrusion along the coast, and diminished streamflow in southwestern Georgia due to irrigation pumping. The map at right shows the USGS ground-water monitoring network for Georgia. Ground-water levels are monitored in 170 wells statewide, of which 19 transmit data in real time via satellite and posted on the World Wide Web at http://waterdata.usgs.gov/ga/nwis/current/?type=gw . A greater concentration of wells occurs in the Coastal Plain where there are several layers of aquifers and in coastal and southwestern Georgia areas, which are areas with specific ground-water issues.

THE CHALLENGE OF ACQUIRING ALPINE LARGE VOLUME LAKE WATER SAMPLES FOR ULTRA TRACE LEVEL ANALYSIS

EPA Science Inventory

The National Exposure Research Laboratory-Las Vegas, Nevada is interested in the emerging field technology of in-situ extraction of contaminants from surface water. A current research project involves ultra-trace level determination of agricultural pesticides from alpine lakes. T...

GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS WHATS WHAT?

EPA Science Inventory

After years of research and many publications, the question still remains: What is the best method to collect representative ground water samples from monitoring wells? Numerous systems and devices are currently available for obtaining both multi-level samples as well as traditi...

Water Resources Data for Illinois - Water Year 2005 (Includes Historical Data)

USGS Publications Warehouse

LaTour, J.K.; Weldon, E.A.; Dupre, D.H.; Halfar, T.M.

2006-01-01

This annual Water-Data Report for Illinois contains current water year (Oct. 1, 2004, to Sept. 30, 2005) and historical data of discharge, stage, water quality and biology of streams; stage of lakes and reservoirs; levels and quality of ground water; and records of precipitation, air temperature, dew point, solar radiation, and wind speed. The current year's (2005) data provided in this report include (1) discharge for 182 surface-water gaging stations and for 9 crest-stage partial-record stations; (2) stage for 33 surface-water gaging stations; (3) water-quality records for 10 surface-water stations; (4) sediment-discharge records for 14 surface-water stations; (5) water-level records for 98 ground-water wells; (6) water-quality records for 17 ground-water wells; (7) precipitation records for 48 rain gages; (8) records of air temperature, dew point, solar radiation and wind speed for 1 meteorological station; and (9) biological records for 6 sample sites. Also included are miscellaneous data collected at various sites not in the systematic data-collection network. Data were collected and compiled as a part of the National Water Information System (NWIS) maintained by the U.S. Geological Survey in cooperation with Federal, State, and local agencies.

Groundwater level and nitrate concentration trends on Mountain Home Air Force Base, southwestern Idaho

USGS Publications Warehouse

Williams, Marshall L.

2014-01-01

Mountain Home Air Force Base in southwestern Idaho draws most of its drinking water from the regional aquifer. The base is located within the State of Idaho's Mountain Home Groundwater Management Area and is adjacent to the State's Cinder Cone Butte Critical Groundwater Area. Both areas were established by the Idaho Department of Water Resources in the early 1980s because of declining water levels in the regional aquifer. The base also is listed by the Idaho Department of Environmental Quality as a nitrate priority area. The U.S. Geological Survey, in cooperation with the U.S. Air Force, began monitoring wells on the base in 1985, and currently monitors 25 wells for water levels and 17 wells for water quality, primarily nutrients. This report provides a summary of water-level and nitrate concentration data collected primarily between 2001 and 2013 and examines trends in those data. A Regional Kendall Test was run to combine results from all wells to determine an overall regional trend in water level. Groundwater levels declined at an average rate of about 1.08 feet per year. Nitrate concentration trends show that 3 wells (18 percent) are increasing in nitrate concentration trend, 3 wells (18 percent) show a decreasing nitrate concentration trend, and 11 wells (64 percent) show no nitrate concentration trend. Six wells (35 percent) currently exceed the U.S. Environmental Protection Agency's maximum contaminant limit of 10 milligrams per liter for nitrate (nitrite plus nitrate, measured as nitrogen).

Many atolls may be uninhabitable within decades due to climate change

USGS Publications Warehouse

Storlazzi, Curt; Elias, Edwin P.L.; Berkowitz, Paul

2015-01-01

Observations show global sea level is rising due to climate change, with the highest rates in the tropical Pacific Ocean where many of the world’s low-lying atolls are located. Sea-level rise is particularly critical for low-lying carbonate reef-lined atoll islands; these islands have limited land and water available for human habitation, water and food sources, and ecosystems that are vulnerable to inundation from sea-level rise. Here we demonstrate that sea-level rise will result in larger waves and higher wave-driven water levels along atoll islands’ shorelines than at present. Numerical model results reveal waves will synergistically interact with sea-level rise, causing twice as much land forecast to be flooded for a given value of sea-level rise than currently predicted by current models that do not take wave-driven water levels into account. Atolls with islands close to the shallow reef crest are more likely to be subjected to greater wave-induced run-up and flooding due to sea-level rise than those with deeper reef crests farther from the islands’ shorelines. It appears that many atoll islands will be flooded annually, salinizing the limited freshwater resources and thus likely forcing inhabitants to abandon their islands in decades, not centuries, as previously thought.

A practical tool for estimating subsurface LNAPL distributions and transmissivity using current and historical fluid levels in groundwater wells: Effects of entrapped and residual LNAPL.

PubMed

Lenhard, R J; Rayner, J L; Davis, G B

2017-10-01

A model is presented to account for elevation-dependent residual and entrapped LNAPL above and below, respectively, the water-saturated zone when predicting subsurface LNAPL specific volume (fluid volume per unit area) and transmissivity from current and historic fluid levels in wells. Physically-based free, residual, and entrapped LNAPL saturation distributions and LNAPL relative permeabilities are integrated over a vertical slice of the subsurface to yield the LNAPL specific volumes and transmissivity. The model accounts for effects of fluctuating water tables. Hypothetical predictions are given for different porous media (loamy sand and clay loam), fluid levels in wells, and historic water-table fluctuations. It is shown the elevation range from the LNAPL-water interface in a well to the upper elevation where the free LNAPL saturation approaches zero is the same for a given LNAPL thickness in a well regardless of porous media type. Further, the LNAPL transmissivity is largely dependent on current fluid levels in wells and not historic levels. Results from the model can aid developing successful LNAPL remediation strategies and improving the design and operation of remedial activities. Results of the model also can aid in accessing the LNAPL recovery technology endpoint, based on the predicted transmissivity. Copyright © 2017 Commonwealth Scientific and Industrial Research Organisation - Copyright 2017. Published by Elsevier B.V. All rights reserved.

Negotiating water across levels: A peace and conflict "Toolbox" for water diplomacy

NASA Astrophysics Data System (ADS)

Grech-Madin, Charlotte; Döring, Stefan; Kim, Kyungmee; Swain, Ashok

2018-04-01

As a key policy tool, water diplomacy offers greater political engagement in the cooperative management of shared water. A range of initiatives has been dedicated to this end, almost invariably oriented around the interactions of nation states. Crucially, however, practitioners of water diplomacy also need to address water governance at sub-state levels. As a political, multi-level, and normative field, peace and conflict research offers a pluralism of approaches designed to bring actors together at all levels. Drawing upon this research, this paper offers new focal points for water diplomacy that can enhance its policy effectiveness and enrich its underlying academic current. More specifically, it presents three hitherto undervalued tools for water diplomacy: at the interstate level, to uncover the rich body of political norms that bind states to shared understandings of acceptable practice around water. At the intrastate level, to incorporate ethnography of water users and civil society groups' responses to state-led waterworks projects, and at the communal level to employ disaggregated georeferenced data on water resources in conflict-prone areas. Taken together, these analytical tools provide a multi-faceted political gauge of the dynamics of water diplomacy, and add vital impetus to develop water diplomacy across multiple levels of policy engagement.

Hydrologic influences on water-level changes in the Eastern Snake River Plain aquifer at and near the Idaho National Laboratory, Idaho, 1949-2014

USGS Publications Warehouse

Bartholomay, Roy C.; Twining, Brian V.

2015-01-01

Geophysical logs indicate that most of the wells evaluated will maintain their current production until the water level declines to the depth of the pump. A few of the wells may become less productive once the water level gets to within about 5 ft from the top of the pump. Wells most susceptible to future drought cycles are those in the northeastern and northwestern areas of the INL.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2013

USGS Publications Warehouse

Beman, Joseph E.

2014-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when treatment and distribution of surface water from the Rio Grande began. A population increase of about 20 percent in the basin from 1990 to 2000 and a 22-percent increase from 2000 to 2010 resulted in an increased demand for water. An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2013), the network consists of 123 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the Albuquerque Bernalillo County Water Utility Authority, currently (2013) measures and reports water levels from the 123 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 123 sites through water year 2013.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2012

USGS Publications Warehouse

Beman, Joseph E.

2013-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25-40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. A population increase of about 20 percent in the basin from 1990 to 2000 and a 22 percent increase from 2000 to 2010 resulted in an increased demand for water. An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2012), the network consists of 126 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the Albuquerque Bernalillo County Water Utility Authority (ABCWUA), currently (2012) measures and reports water levels from the 126 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 126 sites through water year 2012.

Strange bedfellows - A deep-water hermatypic coral reef superimposed on a drowned barrier island; Southern Pulley Ridge, SW Florida platform margin

USGS Publications Warehouse

Jarrett, B.D.; Hine, A.C.; Halley, R.B.; Naar, D.F.; Locker, S.D.; Neumann, A.C.; Twichell, D.; Hu, C.; Donahue, B.T.; Jaap, W.C.; Palandro, D.; Ciembronowicz, K.

2005-01-01

The southeastern component of a subtle ridge feature extending over 200 km along the western ramped margin of the south Florida platform, known as Pulley Ridge, is composed largely of a non-reefal, coastal marine deposit. Modern biostromal reef growth caps southern Pulley Ridge (SPR), making it the deepest hermatypic reef known in American waters. Subsurface ridge strata are layered, lithified, and display a barrier island geomorphology. The deep-water reef community is dominated by platy scleractinian corals, leafy green algae, and coralline algae. Up to 60% live coral cover is observed in 60-75 m of water, although only 1-2% of surface light is available to the reef community. Vertical reef accumulation is thin and did not accompany initial ridge submergence during the most recent sea-level rise. The delayed onset of reef growth likely resulted from several factors influencing Gulf waters during early stages of the last deglaciation (???14 kyr B.P.) including; cold, low-salinity waters derived from discrete meltwater pulses, high-frequency sea-level fluctuations, and the absence of modern oceanic circulation patterns. Currently, reef growth is supported by the Loop Current, the prevailing western boundary current that impinges upon the southwest Florida platform, providing warm, clear, low-nutrient waters to SPR. The rare discovery of a preserved non-reefal lowstand shoreline capped by rich hermatypic deep-reef growth on a tectonically stable continental shelf is significant for both accurate identification of late Quaternary sea-level position and in better constraining controls on the depth limits of hermatypic reefs and their capacity for adaptation to extremely low light levels. ?? 2004 Elsevier B.V. All rights reserved.

Effects of wave-current interaction on storm surge in the Taiwan Strait: Insights from Typhoon Morakot

NASA Astrophysics Data System (ADS)

Yu, Xiaolong; Pan, Weiran; Zheng, Xiangjing; Zhou, Shenjie; Tao, Xiaoqin

2017-08-01

The effects of wave-current interaction on storm surge are investigated by a two-dimensional wave-current coupling model through simulations of Typhoon Morakot in the Taiwan Strait. The results show that wind wave and slope of sea floor govern wave setup modulations within the nearshore surf zone. Wave setup during Morakot can contribute up to 24% of the total storm surge with a maximum value of 0.28 m. The large wave setup commonly coincides with enhanced radiation stress gradient, which is itself associated with transfer of wave momentum flux. Water levels are to leading order in modulating significant wave height inside the estuary. High water levels due to tidal change and storm surge stabilize the wind wave and decay wave breaking. Outside of the estuary, waves are mainly affected by the current-induced modification of wind energy input to the wave generation. By comparing the observed significant wave height and water level with the results from uncoupled and coupled simulations, the latter shows a better agreement with the observations. It suggests that wave-current interaction plays an important role in determining the extreme storm surge and wave height in the study area and should not be neglected in a typhoon forecast.

Variability of High-Resolution Sea Surface Heights on a Broad, Shallow Continental Shelf

NASA Astrophysics Data System (ADS)

Crout, R. L.; Rice, A. E.

2017-12-01

Recent satellite altimeter technologies and processing methodologies are allowing investigation of the dynamics of the continental shelf as never before. The region seaward of 20 km from the coast is a region where winds, tides, currents, river discharge, and bathymetry interact. All of these are important parameters to understand when applying coastal altimetry to coastal sea level monitoring. Processing of 8 years (July 2008 to July 2016) of Jason-2 altimeter 20 Hz data from the L2 AVISO-PISTACH experimental products yields nearly 300 crossings of the broad continental shelf to the southeast of Delaware Bay from Cape May, NJ. Removal of a mean surface yields individual crossings that, plotted together, form an envelope that shows high water level variability near the coast. Water level changes near the coast begin at a hinge point that occurs approximately 50 km from shore in less than 30 meters of water. Comparison of individual Jason-2 passes with regional weather patterns, cold front passages, local winds, tides, surface currents, river discharge, and regional oceanography provides information regarding the forcing factors for these regional water levels. The water levels farther than 20 km from shore show similar patterns to the low pass filtered tide data at Cape May, NJ and respond primarily to regional forcing.

Potentiometric Surface, Carbonate-Rock Province, Southern Nevada and Southeastern California, 1998-2000

DTIC Science & Technology

2001-01-01

cooperation with the Nevada Division of Water Resources. The water-level contours displayed are similar to and modeled after work by Winograd and Thordarson ...ing degrees (Winograd and Thordarson , 1975, p. 19). Although many hydrogeologic properties (including transmissivity, storativity, hydraulic... Thordarson , 1975; Waddell and others, 1984; Thomas and others, 1986, 1996; Laczniak and others, 1996), and are sup- ported only by current water-level

Trends in Water Level and Flooding in Dhaka, Bangladesh and Their Impact on Mortality

PubMed Central

Thiele-Eich, Insa; Burkart, Katrin; Simmer, Clemens

2015-01-01

Climate change is expected to impact flooding in many highly populated coastal regions, including Dhaka (Bangladesh), which is currently among the fastest growing cities in the world. In the past, high mortality counts have been associated with extreme flood events. We first analyzed daily water levels of the past 100 years in order to detect potential shifts in extremes. A distributed lag non-linear model was then used to examine the connection between water levels and mortality. Results indicate that for the period of 2003–2007, which entails two major flood events in 2004 and 2007, high water levels do not lead to a significant increase in relative mortality, which indicates a good level of adaptation and capacity to cope with flooding. However, following low water levels, an increase in mortality could be found. As our trend analysis of past water levels shows that minimum water levels have decreased during the past 100 years, action should be taken to ensure that the exposed population is also well-adapted to drought. PMID:25648177

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2015

USGS Publications Warehouse

Beman, Joseph E.; Bryant, Christina F.

2016-10-27

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is hydrologically defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift between San Acacia to the south and Cochiti Lake to the north. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) began treatment and distribution of surface water from the Rio Grande through the San Juan-Chama Drinking Water Project. A 20-percent population increase in the basin from 1990 to 2000 and a 22-percent population increase from 2000 to 2010 may have resulted in an increased demand for water in areas within the basin.An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the Albuquerque Basin. In 1983, this network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly. The network currently (2015) consists of 124 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the ABCWUA, currently (2015) measures and reports water levels from the 124 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 124 sites through water year 2015 (October 1, 2014, through September 30, 2015).

Evaluation of an operational water cycle prediction system for the Laurentian Great Lakes and St. Lawrence River

NASA Astrophysics Data System (ADS)

Fortin, Vincent; Durnford, Dorothy; Smith, Gregory; Dyck, Sarah; Martinez, Yosvany; Mackay, Murray; Winter, Barbara

2017-04-01

Environment and Climate Change Canada (ECCC) is implementing new numerical guidance products based on fully coupled numerical models to better inform the public as well as specialized users on the current and future state of various components of the water cycle, including stream flow and water levels. Outputs from this new system, named the Water Cycle Prediction System (WCPS), have been available for the Great Lakes and St. Lawrence River watershed since June 2016. WCPS links together ECCC's weather forecasting model, GEM, the 2-D ice model C-ICE, the 3-D lake and ocean model NEMO, and a 2-D hydrological model, WATROUTE. Information concerning the water cycle is passed between the models at intervals varying from a few minutes to one hour. It currently produces two forecasts per day for the next three days of the complete water cycle in the Great Lakes region, the largest freshwater lake system in the world. Products include spatially-varying precipitation, evaporation, river discharge, water level anomalies, surface water temperatures, ice coverage, and surface currents. These new products are of interest to water resources and management authority, flood forecasters, hydroelectricity producers, navigation, environmental disaster managers, search and rescue teams, agriculture, and the general public. This presentation focuses on the evaluation of various elements forecasted by the system, and weighs the advantages and disadvantages of running the system fully coupled.

Drinking water systems, hydrology, and childhood gastrointestinal illness in central and northern Wisconsin

USDA-ARS?s Scientific Manuscript database

Background: Current United States drinking water regulations create areas with different levels of water quality. Municipalities accessing untreated groundwater and households with unmonitored private wells may be at increased risk for acquiring waterborne disease. Objectives: The study investigat...

Coastal circulation and sediment dynamics in Hanalei Bay, Kauai. Part I: Measurements of waves, currents, temperature, salinity and turbidity : June - August, 2005

USGS Publications Warehouse

Storlazzi, Curt D.; Presto, M. Kathy; Logan, Joshua B.; Field, Michael E.

2006-01-01

Introduction: High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Hanalei Bay, northern Kauai, Hawaii, during the summer of 2005 to better understand coastal circulation and sediment dynamics in coral reef habitats. A series of bottom-mounted instrument packages were deployed in water depths of 10 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity. These data were supplemented with a series of vertical instrument casts to characterize the vertical and spatial variability in water column properties within the bay. The purpose of these measurements was to collect hydrographic data to learn how waves, currents and water column properties vary spatially and temporally in an embayment that hosts a nearshore coral reef ecosystem adjacent to a major river drainage. These measurements support the ongoing process studies being conducted as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Coral Reef Project; the ultimate goal is to better understand the transport mechanisms of sediment, larvae, pollutants and other particles in coral reef settings. This report, the first part in a series, describes data acquisition, processing and analysis.

Do changes in climate and land use pose a risk to the future water availability of Mediterranean Lakes?

NASA Astrophysics Data System (ADS)

Bucak, T.; Trolle, D.; Andersen, H. E.; Thodsen, H.; Erdoğan, Ş.; Levi, E. E.; Filiz, N.; Jeppesen, E.; Beklioğlu, M.

2016-12-01

Inter- and intra-annual water level fluctuations and change in water flow regime are intrinsic characteristics of Mediterranean lakes. However, considering the climate change projections for the water-limited Mediterranean region where potential evapotranspiration exceeds precipitation and with increased air temperatures and decreased precipitation, more dramatic water level declines in lakes and severe water scarcity problems are expected to occur in the future. Our study lake, Lake Beyşehir, the largest freshwater lake in the Mediterranean basin, is - like other Mediterranean lakes - under pressure due to water abstraction for irrigated crop farming and climatic changes, and integrated water level management is therefore required. We used an integrated modeling approach to predict the future lake water level of Lake Beyşehir in response to the future changes in both climate and, potentially, land use by linking the catchment model Soil and Water Assessment Tool (SWAT) with a Support Vector Machine Regression model (ɛ-SVR). We found that climate change projections caused enhanced potential evapotranspiration and reduced total runoff, whereas the effects of various land use scenarios within the catchment were comparatively minor. In all climate scenarios applied in the ɛ-SVR model, changes in hydrological processes caused a water level reduction, predicting that the lake may dry out already in the 2040s with the current outflow regulation considering the most pessimistic scenario. Based on model runs with optimum outflow management, a 9-60% reduction in outflow withdrawal is needed to prevent the lake from drying out by the end of this century. Our results indicate that shallow Mediterranean lakes may face a severe risk of drying out and loss of ecosystem value in near future if the current intense water abstraction is maintained. Therefore, we conclude that outflow management in water-limited regions in a warmer and drier future and sustainable use of water sources are vitally important to sustain lake ecosystems and their ecosystem services.

High temporal resolution modeling of the impact of rain, tides, and sea level rise on water table flooding in the Arch Creek basin, Miami-Dade County Florida USA.

PubMed

Sukop, Michael C; Rogers, Martina; Guannel, Greg; Infanti, Johnna M; Hagemann, Katherine

2018-03-01

Modeling of groundwater levels in a portion of the low-lying coastal Arch Creek basin in northern Miami-Dade County in Southeast Florida USA, which is subject to repetitive flooding, reveals that rain-induced short-term water table rises can be viewed as a primary driver of flooding events under current conditions. Areas below 0.9m North American Vertical Datum (NAVD) elevation are particularly vulnerable and areas below 1.5m NAVD are vulnerable to exceptionally large rainfall events. Long-term water table rise is evident in the groundwater data, and the rate appears to be consistent with local rates of sea level rise. Linear extrapolation of long-term observed groundwater levels to 2060 suggest roughly a doubling of the number of days when groundwater levels exceed 0.9m NAVD and a threefold increase in the number of days when levels exceed 1.5m NAVD. Projected sea level rise of 0.61m by 2060 together with increased rainfall lead to a model prediction of frequent groundwater-related flooding in areas<0.9m NAVD. However, current simulations do not consider the range of rainfall events that have led to water table elevations>1.5m NAVD and widespread flooding of the area in the past. Tidal fluctuations in the water table are predicted to be more pronounced within 600m of a tidally influenced water control structure that is hydrodynamically connected to Biscayne Bay. The inland influence of tidal fluctuations appears to increase with increased sea level, but the principal driver of high groundwater levels under the 2060 scenario conditions remains groundwater recharge due to rainfall events. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of water management variation on As and Cd accumulation or rice grain

USDA-ARS?s Scientific Manuscript database

Because of the current interest in As accumulation in rice, we examined rice grain As and Cd levels from a field test evaluating the effect of irrigation water management. The original study was conducted to test water saving production methods because limitation on water supply is constraining prod...

Water-quality assessment of Francis E Walter reservoir, Luzerne and Carbon counties, Pennsylvania

USGS Publications Warehouse

Barker, J.L.

1983-01-01

Water-quality data, both past and present, show that the waters of the upper Lehigh River basin are somewhat acidic, but otherwise are generally of good quality. This report contains a summary of all known water-quality data collected by the U.S. Geological Survey and other agencies, as well as a synopsis of current water-quality conditions in the reservoir and its tributaries. Water-quality data collected from June 1981 to May 1982 indicate that raising the pool level from 1,300 to approximately 1,392 feet above sea level (NGVD of 1929) has had some significant, if only temporary, detrimental impacts on the reservoir system and its discharge. Depth profile measurements show that, while the impoindment was thermally stratified for only about 2 weeks, the dissolved oxygen concentrations were depressed to levels critical to fishlife throughout much of the reservoir. Another effect of the raised pool was the lowering of pH in the impoinded water. Median pH values were less than 6.0 throughout the reservoir, whereas they commonly exceeded 6.5 at the normal pool elevation. Tests for fecal coliform and fecal streptococcus indicate the impoinded water is nearly free of enteric bacteria. Algal analyses and nutrient concentrations support the premise that the impoundment is nutrient poor and phosphorus limited. Raising the water level an additional 125 feet should have no permanent detrimental effect upon water quality and will greatly increase available habitat for fish and waterflow. Increased retention time should not alter the current trophic status and may decrease the concentration of available nutrients.

Modelling tidal current energy extraction in large area using a three-dimensional estuary model

NASA Astrophysics Data System (ADS)

Chen, Yaling; Lin, Binliang; Lin, Jie

2014-11-01

This paper presents a three-dimensional modelling study for simulating tidal current energy extraction in large areas, with a momentum sink term being added into the momentum equations. Due to the limits of computational capacity, the grid size of the numerical model is generally much larger than the turbine rotor diameter. Two models, i.e. a local grid refinement model and a coarse grid model, are employed and an idealized estuary is set up. The local grid refinement model is constructed to simulate the power generation of an isolated turbine and its impacts on hydrodynamics. The model is then used to determine the deployment of turbine farm and quantify a combined thrust coefficient for multiple turbines located in a grid element of coarse grid model. The model results indicate that the performance of power extraction is affected by array deployment, with more power generation from outer rows than inner rows due to velocity deficit influence of upstream turbines. Model results also demonstrate that the large-scale turbine farm has significant effects on the hydrodynamics. The tidal currents are attenuated within the turbine swept area, and both upstream and downstream of the array. While the currents are accelerated above and below turbines, which is contributed to speeding up the wake mixing process behind the arrays. The water levels are heightened in both low and high water levels as the turbine array spanning the full width of estuary. The magnitude of water level change is found to increase with the array expansion, especially at the low water level.

Soil salinity mapping and hydrological drought indices assessment in arid environments based on remote sensing techniques

NASA Astrophysics Data System (ADS)

Elhag, Mohamed; Bahrawi, Jarbou A.

2017-03-01

Vegetation indices are mostly described as crop water derivatives. The normalized difference vegetation index (NDVI) is one of the oldest remote sensing applications that is widely used to evaluate crop vigor directly and crop water relationships indirectly. Recently, several NDVI derivatives were exclusively used to assess crop water relationships. Four hydrological drought indices are examined in the current research study. The water supply vegetation index (WSVI), the soil-adjusted vegetation index (SAVI), the moisture stress index (MSI) and the normalized difference infrared index (NDII) are implemented in the current study as an indirect tool to map the effect of different soil salinity levels on crop water stress in arid environments. In arid environments, such as Saudi Arabia, water resources are under pressure, especially groundwater levels. Groundwater wells are rapidly depleted due to the heavy abstraction of the reserved water. Heavy abstractions of groundwater, which exceed crop water requirements in most of the cases, are powered by high evaporation rates in the designated study area because of the long days of extremely hot summer. Landsat 8 OLI data were extensively used in the current research to obtain several vegetation indices in response to soil salinity in Wadi ad-Dawasir. Principal component analyses (PCA) and artificial neural network (ANN) analyses are complementary tools used to understand the regression pattern of the hydrological drought indices in the designated study area.

Potential and limitations of satellite laser altimetry for monitoring water surface dynamics: ICESat for US lakes

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

Shu, Liu; Qigang, Jiang; Zhang, Xuesong

Elevation measurements from the Ice, Cloud and Land Elevation Satellite (ICESat) have been applied to monitor dynamics of lakes and other surface water bodies. Despite such potential, the true utility of ICESat--more generally, satellite laser altimetry--for tracking surface water dynamics over time has not been adequately assessed, especially in the continental or global contexts. Here, we analyzed ICESat elevation data for the conterminous United States and examined the potential and limitations of satellite laser altimetry in measuring water-level dynamics. Owing to a lack of spatially-explicit ground-based water-level data, we first resorted to high-fidelity land elevation data acquired by airborne lidarmore » to quantify ICESat’s ranging accuracy. We then performed trend and frequency analyses to evaluate how reliably ICESat could capture water-level dynamics over a range of temporal scales, as compared to in-situ gauge measurements. Our analyses showed that ICESat had a vertical ranging error of 0.16 m at the footprint level—a limit on the detectable range of water-level dynamics. The sparsity of data over time was identified as a major factor limiting the use of ICESat for water dynamics studies. Of all the US lakes, only 361 had quality ICESat measurements for more than two flight passes. Even for those lakes with sufficient temporal coverage, ICESat failed to capture the true interannual water-level dynamics in 68% of the cases. Our frequency analysis suggested that even with a repeat cycle of two months, ICESat could capture only 60% of the variations in water-level dynamics for at most 34 % of the US lakes. To capture 60% of the water-level variation for most of the US lakes, a weekly repeat cycle (e.g., less than 5 days) is needed – a requirement difficult to meet in current designs of spaceborne laser altimetry. Overall, our results highlight that current or near-future satellite laser missions, though with high ranging accuracies, are unlikely to fulfill the general needs in remotely monitoring water surface dynamics for lakes or reservoirs.« less

Coastal Storm Hazards from Virginia to Maine

DTIC Science & Technology

2015-11-01

study, storm surge, tide, waves, wind, atmospheric pressure, and currents were the dominant storm responses computed. The effect of sea level change on...coastal storm hazards and vulnerability nationally (USACE 2015). NACCS goals also included evaluating the effect of future sea level change (SLC) on...the computed high-fidelity responses included storm surge, astronomical tide, waves, wave effects on water levels, storm duration, wind, currents

Patterns, structures and regulations of domestic water cycle systems in China

NASA Astrophysics Data System (ADS)

Chu, Junying; Wang, Hao; Wang, Jianhua; Qin, Dayong

2010-05-01

Domestic water cycle systems serving as one critical component of artificial water cycle at the catchment's scale, is so closely related to public healthy, human rights and social-economic development, and has gained the highest priority in strategic water resource and municipal infrastructure planning. In this paper, three basic patterns of domestic water cycle systems are identified and analyzed, including rural domestic water system (i.e. primary level), urban domestic water system (i.e. intermediate level) and metropolitan domestic water system (i.e. senior level), with different "abstract-transport-consume-discharge" mechanisms and micro-components of water consumption (such as drinking, cooking, toilet flushing, showering or cleaning). The rural domestic water system is general simple with three basic "abstract-consume-discharge" mechanisms and micro-components of basic water consumption such as drinking, cooking, washing and sanitation. The urban domestic water system has relative complex mechanisms of "abstract-supply-consume-treatment-discharge" and more micro-components of water consumption such as bath, dishwashing or car washing. The metropolitan domestic water system (i.e. senior level) has the most complex mechanisms by considering internal water reuse, external wastewater reclamation, and nutrient recycling processes. The detailed structures for different water cycle pattern are presented from the aspects of water quantity, wastewater quality and nutrients flow. With the speed up of urbanization and development of social-economy in China, those three basic patterns are interacting, transforming and upgrading. According to the past experiences and current situations, urban domestic water system (i.e. intermediate level) is the dominant pattern based on indicator of system number or system scale. The metropolitan domestic water system (i.e. senior level) is the idealized model for the future development and management. Current domestic water system management efforts typically fail in China, because the approach is generally narrowly-focused and fragmented. This paper put forward a total-process control framework following the water and pollutants (or nutrients) flows along the dualistic domestic water cycle process. Five key objectives of domestic water cycle system regulation are identified including water use safety, water use equity, water saving, wastewater reduction and nutrient recycling. Comprehensive regulatory framework regarding administrative, economic, technical and social measures is recommended to promote sustainable domestic water usage and demand management. Considering the relatively low affordability in rural area, economic measures should be mainly applied in urban domestic water systems and metropolitan domestic water systems. Engineering or technological measures which are suitable to the three domestic water cycle systems are discussed respectively.

The Enterococcus QPCR Method for Recreational Water Quality Testing: Testing Background, Performance and Issues

EPA Science Inventory

Currently accepted culture-based monitoring methods for fecal indicator bacteria in surface waters take at least 24 hr to determine if unacceptable levels of fecal pollution have reached our recreational beaches. During this waiting period changing water conditions may result eit...

Measuring nutrient flux in Pacific Coast salt marshes using fluctuating water-level chambers

EPA Science Inventory

Nutrient removal from the water column is an important ecosystem function that contributes to the production of clean water, a final valued ecosystem service of wetlands. However, little data is currently available for nutrient exchange in Pacific Northwest tidal ecosystems. We h...

Simulation of Ground-Water Flow in the Irwin Basin Aquifer System, Fort Irwin National Training Center, California

USGS Publications Warehouse

Densmore, Jill N.

2003-01-01

Ground-water pumping in the Irwin Basin at Fort Irwin National Training Center, California resulted in water-level declines of about 30 feet from 1941 to 1996. Since 1992, artificial recharge from wastewater-effluent infiltration and irrigation-return flow has stabilized water levels, but there is concern that future water demands associated with expansion of the base may cause a resumption of water-level declines. To address these concerns, a ground-water flow model of the Irwin Basin was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Historical data show that ground-water-level declines in the Irwin Basin between 1941 and 1996, caused the formation of a pumping depression near the pumped wells, and that recharge from the wastewater-treatment facility and disposal area caused the formation of a recharge mound. There have been two periods of water-level recovery in the Irwin Basin since the development of ground water in this basin; these periods coincide with a period of decreased pumpage from the basin and a period of increased recharge of water imported from the Bicycle Basin beginning in 1967 and from the Langford Basin beginning in 1992. Since 1992, artificial recharge has exceeded pumpage in the Irwin Basin and has stabilized water-level declines. A two-layer ground-water flow model was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Boundary conditions, hydraulic conductivity, altitude of the bottom of the layers, vertical conductance, storage coefficient, recharge, and discharge were determined using existing geohydrologic data. Rates and distribution of recharge and discharge were determined from existing data and estimated when unavailable. Results of predictive simulations indicate that in 50 years, if artificial recharge continues to exceed pumpage in Irwin Basin, water levels could rise as much as 65 feet beneath the pumping depression, and as much as 10 feet in the wastewater-treatment facility and disposal area. Particle-tracking simulations were used to determine the pathlines and the traveltimes of water high in dissolved solids into the main pumping area. The pathlines of particles from two areas with high dissolved-solids concentrations show that in 50 years water from these areas almost reaches the nearest pumped well.

Projections of extreme water level events for atolls in the western Tropical Pacific

NASA Astrophysics Data System (ADS)

Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

2014-12-01

Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

[Research on ecological population capacity based on food and water in Shandong province].

PubMed

Lin, C

1991-02-01

The population carrying capacity in Shandong Province, China, based on current food production and water supply is discusses. In 1988, the staple food production exceeded the amount needed for the minimum subsistence level of 300 kg/person. But if the food supply were to be kept at 500 kilos/person, the amount considered to be abundant, the province had a surplus population of 16.11 million. Based on a population projection of medium scenario, the projected level of food production would meet the needs for adequate food consumption. But if the level of abundant supply were to be kept, there would be 12.4 million surplus population. The shortage of water supply is a more acute problem. On the basis of the current water consumption of 514 cubic m/person, the water supply of the province could only meet the needs of 44.9 million. But the population in the province was already 80.6 million in 1988. If the water consumption was 1000 cubic m/person, which was the consumption level of the Soviet Union, the supply can only meet the needs of 23 million population. Even if the potential water resources were fully developed, the supply can only meet the needs of 65.4 million people at the end of the century. The 92.5 million projected population at the time would far exceed the water supply capacity. The severe shortage of water supply of the province would be the most serious ecological problem. Such constraint may also have considerable impact on the sustained socioeconomic development of the province.

Statistical analysis of long-term hydrologic records for selection of drought-monitoring sites on Long Island, New York

USGS Publications Warehouse

Busciolano, Ronald J.

2005-01-01

Ground water is the sole source of water supply for more than 3 million people on Long Island, New York. Large-scale ground-water pumpage, sewering systems, and prolonged periods of below-normal precipitation have lowered ground-water levels and decreased stream-discharge in western and central Long Island. No method is currently (2004) available on Long Island that can assess data from the ground-water-monitoring network to enable water managers and suppliers with the ability to give timely warning of severe water-level declines.This report (1) quantifies past drought- and human-induced changes in the ground-water system underlying Long Island by applying statistical and graphical methods to precipitation, stream-discharge, and ground-water-level data from selected monitoring sites; (2) evaluates the relation between water levels in the upper glacial aquifer and those in the underlying Magothy aquifer; (3) defines trends in stream discharge and ground-water levels that might indicate the onset of drought conditions or the effects of excessive pumping; and (4) discusses the long-term records that were used to select sites for a Long Island drought-monitoring network.Long Island’s long-term hydrologic records indicated that the available data provide a basis for development of a drought-monitoring network. The data from 36 stations that were selected as possible drought-monitoring sites—8 precipitation-monitoring stations, 8 streamflow-gaging (discharge) stations, 15 monitoring wells screened in the upper glacial aquifer under water-table (unconfined) conditions, and 5 monitoring wells screened in the underlying Magothy aquifer under semi-confined conditions—indicate that water levels in western parts of Long Island have fallen and risen markedly (more than 15 ft) in response to fluctuations in pumpage, and have declined from the increased use of sanitary- and storm-sewer systems. Water levels in the central and eastern parts, in contrast, remain relatively unaffected compared to the western parts, although the effects of human activity are discernible in the records.The value of each site as a drought-monitoring indicator was assessed through an analysis of trends in the records. Fifty-year annual and monthly data sets were created and combined into three composite-average hydrographs—precipitation, stream discharge, and ground-water levels. Three zones representing the range of human effect on ground-water levels were delineated to help evaluate islandwide hydrologic conditions and to quantify the indices. Data from the three indices can be used to assess current conditions in the ground-water system underlying Long Island and evaluate water-level declines during periods of drought.

Coastal circulation and sediment dynamics along West Maui, Hawaii; PART IV: measurements of waves, currents, temperature, salinity and turbidity in Honolua Bay, Northwest Maui: 2003-2004

USGS Publications Warehouse

Storlazzi, Curt D.; Presto, M. Kathy

2005-01-01

High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Honolua Bay, northwest Maui, Hawaii, during 2003 and 2004 to better understand coastal dynamics in coral reef habitats. Measurements were acquired through two different collection methods. Two hydrographic survey cruises were conducted to acquire spatially-extensive, but temporally-limited, three-dimensional measurements of currents, temperature, salinity and turbidity in the winter and summer of 2003. From mid 2003 through early 2004, a bottom-mounted instrument package was deployed in a water depth of 10 m to collect long-term, single-point high-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity. The purpose of these measurements was to collect hydrographic data to learn how waves, currents and water column properties such as water temperature, salinity and turbidity vary spatially and temporally in a near-shore coral reef system adjacent to a major stream drainage. These measurements support the ongoing process studies being conducted as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Coral Reef Project; the ultimate goal is to better understand the transport mechanisms of sediment, larvae, pollutants and other particles in coral reef settings. This report, the final part in a series, describes data acquisition, processing and analysis. Previous reports provided data and results on: Long-term measurements of currents, temperature, salinity and turbidity off Kahana (PART I), the spatial structure of currents, temperature, salinity and suspended sediment along West Maui (PART II), and flow and coral larvae and sediment dynamics during the 2003 summer spawning season (PART III).

Water-Level Data for the Albuquerque Basin and Adjacent Areas, Central New Mexico, Period of Record Through 2004

USGS Publications Warehouse

DeWees, R.K.

2006-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the Albuquerque Basin are obtained solely from ground-water resources. An increase of approximately 20 percent in the population from 1991 to present also resulted in an increased demand for water. From April 1982 through September 1983, a network of wells was established to monitor changes in ground-water levels throughout the Albuquerque Basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly. Currently (2004), the network consists of 234 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 155 sites through 2004. Water-level and other data for 71 sites are collected by other agencies. Water-level data for 8 sites of the 155 sites measured by the U.S. Geological Survey were not available for this report.

Development of a coastal information system for the management of Jeddah coastal waters in Saudi Arabia

NASA Astrophysics Data System (ADS)

Mayerle, R.; Al-Subhi, A.; Fernández Jaramillo, J.; Salama, A.; Bruss, G.; Zubier, K.; Runte, K.; Turki, A.; Hesse, K.; Jastania, H.; Ladwig, N.; Mudarris, M.

2016-04-01

This paper presents results of the development and application of a web-based information system, Jeddah CIS, for assisting decision makers in the management of Jeddah coastal waters, in Saudi Arabia. The system will support coastal planning, management of navigation and tackle pollution due to accidents. The system was developed primarily to nowcast in quasi-real time and to deliver short-term forecasts of water levels, current velocities and waves with high spatial and temporal resolution for the area near Jeddah. Therefor it will hasten response when adverse weather conditions prevail. The Jeddah-CIS integrates sensors transmitting in real time, meteorological, oceanographic and water quality parameters and operational models for flow and waves. It also provides interactive tools using advanced visualization techniques to facilitate dissemination of information. The system relies on open source software and has been designed to facilitate the integration of additional components for enhanced information processing, data evaluation and generation of higher water level, current velocity and wave for the general public. Jeddah-CIS has been operational since 2013. Extensions of the system to speed operations and improving the accuracy of the predictions to the public are currently underway.

Soil and Water Indicators of the Sustainable Rangelands Roundtable

Treesearch

M.G. Sherm Karl; D.A. Pyke; P.T. Tueller; G.E. Schuman; R.W. Shafer; S.J. Borchard; D.T. Booth; W.G. Ypsilantis; R.H. Jr. Barrett

2006-01-01

The Sustainable Rangelands Roundtable (SRR) has explicitly included conservation and maintenance of soil and water resources as a criterion, a category of conditions or processes that can be assessed nationally to determine if the current level of rangeland management will ensure sustainability. Within the soil/water criterion, 10 indicators, 5 soil-based and 5 water-...

Interaction of potato production systems and the environment: a case of waste water irrigation in central Washington.

PubMed

Wang, H Holly; Tan, Tih Koon; Schotzko, R Thomas

2007-02-01

Potato production and processing are very important activities in the agricultural economy of the Pacific Northwest. Part of the reason for the development of this industry has been the availability of water for both growing and processing. A great amount of water is used in processing potato products, such as frozen French fries, and the waste water is a pollutant because it contains high levels of nitrate and other nutrients. Using this waste water to irrigate the fields can be a suitable disposal method. Field application will reduce potato fertilizer costs, but it can also cause underground water contamination if over-applied to the field. In this econometric study, we used field data associated with current waste water applications in central Washington to examine the yield response as well as the soil nitrogen content response to waste water applications. Our results from the production model show that both water and nitrogen positively affect crop yields at the current levels of application, but potassium has been over applied. This implies that replacing some waste water with fresh water and nitrogen fertilizer will increase production. The environmental model results show that applying more nitrogen to the soil leads to more movement below the root zone. The results also suggest that higher crop yields lead to less nitrogen in the soil, and applying more water increases crop yields, which can reduce the nitrogen left in the soil. Therefore, relative to the current practice, waste water application rates should be reduced and supplemented with fresh water to enhance nitrogen use by plants and reduce residual nitrogen in the soil.

THE OCCURRENCE OF CONTAMINANT ACCUMULATION IN LEAD PIPE SCALES FROM DOMESTIC DRINKING WATER DISTRIBUTION SYSTEMS

EPA Science Inventory

Previous work has shown that contaminants, such as Al, As and Ra, can accumulate in drinking water distribution system solids. The release of accumulated contaminants back into the water supply could result in elevated levels at consumers’ taps, and current monitoring practices d...

The Occurrence of Contaminant Accumulation in Lead Pipe Scales from Domestic Drinking Water Distribution Systems-ABSTRACT

EPA Science Inventory

Previous work has shown that contaminants such as Al, As and Ra, can accumulate in drinking water distribution system solids. The release of accumulated contaminants back into the water supply could conceivably result in elevated levels at consumers’ taps. The current regulatory...

Ground-water levels in aquifers used for residential supply, Campton Township, Kane County, Illinois

USGS Publications Warehouse

Kay, Robert T.; Kraske, Kurt A.

1996-01-01

The U.S. Geological Survey, in cooperation with the Campton Township Board of Trustees, measured water levels in the aquifers used for residential supply in Campton Township, Kane County, Illinois. Aquifers used for residential supply are the shallow and deep aquifers in the glacial drift, composed of unconsolidated sand and gravels; the Alexandrian-Maquoketa aquifer, composed of dolomite and shale of the Alexandrian Series and the Maquoketa Group; the Galena-Platteville aquifer, composed of dolomite of the Platteville and Galena Groups; and the Ancell aquifer, composed of sandstones of the Glenwood Formation and the St. Peter Sanstone. Water-level altitudes in the shallow drift aquifers generally follow surface topography. Analysis of water-level data does not clearly indicate overutilization of these aquifers. Water-level altitudes in the deep drift aquifers decrease from west to east. Comparison of historical depth to water measurements with current (1995) measurements indicates large decreases in water levels in some areas. The deep drift aquifers may be overutilized at these locations. Water-level altitudes in the Alexandrian-Maquoketa aquifer generally decrease from west to east. The potentiometric surface of the aquifer follows the bedrock-surface topography in some locations. Localized low water-level altitudes and large decreases in water levels indicate the Alexandrian-Maquoketa aquifer is overutilized in several areas. Water-level altitudes in the wells finished in the Galena- Platteville aquifer vary by more than 300 feet. Large decreases in water levels in wells finished in the Galena-Platteville aquifer indicate the Galena-Platteville and Alexandrian-Maquoketa aquifers are overutilized in the northern part of the township. Water-level altitudes in the wells finished in the Ancell aquifer are also highly variable. There is no indication that the Ancell aquifer is overutilized.

Seasonal variation of the water exchange through the Bohai Strait

NASA Astrophysics Data System (ADS)

Zhang, Z.

2016-02-01

Seasonal variations of the Lubei coastal current off the northern Shandong Peninsula and water exchange between the Bohai and Yellow seas were analyzed, based on current and salinity data measured mainly in 2006, 2007 and 2012. In winter and autumn, the Lubei coastal current flows eastward through the Bohai Strait before ultimately heading southward into the waters off Chengshantou in the east of the Shandong Peninsula. In spring and summer, the Lubei coastal current disappears. There are three kinds of patterns of water exchange between the Bohai and Yellow seas. The first is the "inflow in the north and outflow in the south of the Bohai Strait" in winter and autumn, which is regarded as the permanent pattern during the whole year from literature. The second is "outflow in the surface layer and inflow in the underlying layer" in summer, where the outflow is significantly greater than the inflow related with increased runoff and precipitation. The third is "inflow together in the southern and northern channels of the Bohai Strait" in spring. The low mean sea level and N-S sea-level incline formed in winter in the Bohai Sea lose their dynamic balance because of the reversal of the northeast monsoon in spring. This forces the water from the northern Yellow Sea into the Bohai Sea via the southern and northern channels of the Bohai Strait, which constitutes the largest net inflow of the four seasons.

Effects of Hydrological and Biological Factors on Fine Benthic Organic Matter at a Forested River in Yahagi Basin, Japan

NASA Astrophysics Data System (ADS)

Matsumoto, Y.; Inoue, T.

2009-12-01

The role of fine particle organic matters (FPOM) is important in the energy source of benthic organisms and microbes and organic transportation from terrestrial water ecosystem to costal water ecosystem. Accumulated FPOM at a river bed is called Fine benthic organic matter (FBOM). It is considered that FBOM is the source of FPOM at the flood period. But the mechanism of the accumulation and the flush of FBOM are not concerned in research. In this research, we examined effects of hydrological and biological factors on FBOM. The purpose of this research is 1) the routine sampling of FBOM for the collecting basic FBOM data, 2) the examination of the relationship between of the water level or the current velocity and the mass of FBOM, 3) the determination of the FBOM mass of microbial decomposition by a double exponential model. This study was conducted in Tomoe river which was substream of Yahagi river whose length was 117km, located at central of Honshu Island, Japan. The above sea level of the sampling site is 320m and 75km upstream from an estuary. The drainage basin is covered over 90 % by a forest. The stream bed is covered by the coarse fragment and sand. The barrage of a hydroelectric power plant is located at 100m downstream from the sampling site. The sampling area was 30 cm diameter divided by the polyethylene barrel. These samples were divided into two fractions: Coarse-Sediment, over 1mm and Fine-Sediment, 2mm - 63μm. FBOM and CBOM were determined from the amount of carbon containing in Fine-Sediment and Coarse-Sediment. Total C and Total N were measured by CN coder. The water level of river was measured by a level rod and the surface current velocity was measured by a floater at a sampling day. Sampling of FBOM was performed every 2 weeks from the end of August 2008 to the middle of April 2009. The heavy precipitation(98.0 mm/day) was measured at the end of August. This precipitation caused highest water level and fastest current velocity of river during this investigation. The water level of river decreased gradually after the end of August. There were small rain events during September to December, but these events did not let the water level increased. The mass of FBOM collected 0.2(g/m2) at the end of August. The mass of FBOM was increased and decreased between September and October. The mass of FBOM was 4.5(g/m2) at the end of October, subsequently decreased 0.5(g/m2) gradually at April 2009. These investigations showed that FBOM is decreased severely by the large flood, but the other factors are influenced to the FBOM fluctuation. As the effect of hydrology on FBOM, the mass of FBOM was decreased with increasing the water level during the water level increasing period. But the mass of FBOM had the negative relationship with the current velocity during the water level deceasing period. CN ratio of CBOM was larger than that of FBOM. This means that FBOM is biodegraded by organisms from CBOM or CPOM. Then the calculated result of the ratio of decomposition of FBOM was showed that the biodegraded mass of FBOM from CBOM might be less affected than hydrological factors during 2 weeks at investigation site.

Water-level altitudes 2009 and water-level changes in the Chicot, Evangeline, and Jasper Aquifers and compaction 1973-2008 in the Chicot and Evangeline Aquifers, Houston-Galveston Region, Texas

USGS Publications Warehouse

Kasmarek, Mark C.; Houston, Natalie A.; Ramage, Jason K.

2009-01-01

This report, done in cooperation with the Harris-Galveston Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District, is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report (excluding appendixes) contains 16 sheets and 15 tables: 3 sheets are maps showing current-year (2009) water-level altitudes for each aquifer, respectively; 3 sheets are maps showing 1-year (2008-09) water-level changes for each aquifer, respectively; 3 sheets are maps showing 5-year (2004-09) water-level changes for each aquifer, respectively; 4 sheets are maps showing long-term (1990-2009 and 1977-2009) water-level changes for the Chicot and Evangeline aquifers, respectively; 1 sheet is a map showing long-term (2000-2009) water-level change for the Jasper aquifer; 1 sheet is a map showing site locations of borehole extensometers; and 1 sheet comprises graphs showing measured compaction of subsurface material at the sites from 1973 or later through 2008, respectively. Tables listing the data used to construct the aquifer-data maps and the compaction graphs are included.

How Much Will It Cost To Monitor Microbial Drinking Water Quality in Sub-Saharan Africa?

PubMed Central

2017-01-01

Microbial water quality monitoring is crucial for managing water resources and protecting public health. However, institutional testing activities in sub-Saharan Africa are currently limited. Because the economics of water quality testing are poorly understood, the extent to which cost may be a barrier to monitoring in different settings is unclear. This study used cost data from 18 African monitoring institutions (piped water suppliers and health surveillance agencies in six countries) and estimates of water supply type coverage from 15 countries to assess the annual financial requirements for microbial water testing at both national and regional levels, using World Health Organization recommendations for sampling frequency. We found that a microbial water quality test costs 21.0 ± 11.3 USD, on average, including consumables, equipment, labor, and logistics, which is higher than previously calculated. Our annual cost estimates for microbial monitoring of piped supplies and improved point sources ranged between 8 000 USD for Equatorial Guinea and 1.9 million USD for Ethiopia, depending primarily on the population served but also on the distribution of piped water system sizes. A comparison with current national water and sanitation budgets showed that the cost of implementing prescribed testing levels represents a relatively modest proportion of existing budgets (<2%). At the regional level, we estimated that monitoring the microbial quality of all improved water sources in sub-Saharan Africa would cost 16.0 million USD per year, which is minimal in comparison to the projected annual capital costs of achieving Sustainable Development Goal 6.1 of safe water for all (14.8 billion USD). PMID:28459563

How Much Will It Cost To Monitor Microbial Drinking Water Quality in Sub-Saharan Africa?

PubMed

Delaire, Caroline; Peletz, Rachel; Kumpel, Emily; Kisiangani, Joyce; Bain, Robert; Khush, Ranjiv

2017-06-06

Microbial water quality monitoring is crucial for managing water resources and protecting public health. However, institutional testing activities in sub-Saharan Africa are currently limited. Because the economics of water quality testing are poorly understood, the extent to which cost may be a barrier to monitoring in different settings is unclear. This study used cost data from 18 African monitoring institutions (piped water suppliers and health surveillance agencies in six countries) and estimates of water supply type coverage from 15 countries to assess the annual financial requirements for microbial water testing at both national and regional levels, using World Health Organization recommendations for sampling frequency. We found that a microbial water quality test costs 21.0 ± 11.3 USD, on average, including consumables, equipment, labor, and logistics, which is higher than previously calculated. Our annual cost estimates for microbial monitoring of piped supplies and improved point sources ranged between 8 000 USD for Equatorial Guinea and 1.9 million USD for Ethiopia, depending primarily on the population served but also on the distribution of piped water system sizes. A comparison with current national water and sanitation budgets showed that the cost of implementing prescribed testing levels represents a relatively modest proportion of existing budgets (<2%). At the regional level, we estimated that monitoring the microbial quality of all improved water sources in sub-Saharan Africa would cost 16.0 million USD per year, which is minimal in comparison to the projected annual capital costs of achieving Sustainable Development Goal 6.1 of safe water for all (14.8 billion USD).

Water-level altitudes 2008 and water-level changes in the Chicot, Evangeline, and Jasper Aquifers and compaction 1973-2007 in the Chicot and Evangeline Aquifers, Houston-Galveston Region, Texas

USGS Publications Warehouse

Kasmarek, Mark C.; Houston, Natalie A.

2008-01-01

This report, done in cooperation with the Harris-Galveston Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District, is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report contains 17 sheets and 16 tables: 3 sheets are maps showing current-year (2008) water-level altitudes for each aquifer, respectively; 3 sheets are maps showing 1-year (2007-08) water-level changes for each aquifer, respectively; 3 sheets are maps showing 5-year (2003-08) water-level changes for each aquifer, respectively; 4 sheets are maps showing long-term (1990-2008 and 1977-2008) water-level changes for the Chicot and Evangeline aquifers, respectively; 1 sheet is a map showing long-term (2000-2008) water-level change for the Jasper aquifer; 1 sheet is a revision of a previously published water-level-altitude map for the Jasper aquifer for 2003; 1 sheet is a map showing site locations of borehole extensometers; and 1 sheet comprises graphs showing measured compaction of subsurface material at the sites from 1973 or later through 2007, respectively. Tables listing the data used to construct the aquifer-data maps and the compaction graphs are included.

Water-level altitudes 2007 and water-level changes in the Chicot, Evangeline, and Jasper Aquifers and compaction 1973-2006 in the Chicot and Evangeline Aquifers, Houston-Galveston Region, Texas

USGS Publications Warehouse

Kasmarek, Mark C.; Houston, Natalie A.

2007-01-01

This report, done in cooperation with the Harris-Galveston Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District, is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston, Texas, region. The report contains 18 sheets and 17 tables: 3 sheets are maps showing current-year (2007) water-level altitudes for each aquifer, respectively; 3 sheets are maps showing 1-year (2006-07) water-level changes for each aquifer, respectively; 3 sheets are maps showing 5-year (2002-07) water-level changes for each aquifer, respectively; 4 sheets are maps showing long-term (1990-2007 and 1977-2007) water-level changes for the Chicot and Evangeline aquifers, respectively; 1 sheet is a map showing long-term (2000-2007) water-level change for the Jasper aquifer; 2 sheets are revisions of previously published water-level-altitude maps for the Jasper aquifer for 2000 and 2002, respectively; 1 sheet is a map showing site locations of borehole extensometers; and 1 sheet comprises graphs showing measured compaction of subsurface material at the sites from 1973 or later through 2006, respectively. Tables listing the data used to construct the aquifer-data maps and the compaction graphs also are included.

Influence of marine current on vertical migration of Pb in marine bay

NASA Astrophysics Data System (ADS)

Yu, Chen; Hong, Ai; Danfeng, Yang; Huijuan, Zhao; Dongfang, Yang

2018-02-01

This paper analyzed that vertical migration of Pb contents waters in Jiaozhou Bay, and revealed the influence of marine current on vertical migration process. Results showed that Pb contents in bottom waters of Jiaozhou Bay in April and July 1988 were 1.49-18.53 μg L-1 and 12.68/-27.64 μg L-1, respectively. The pollution level of Pb in bottom waters was moderate to heavy, and were showing temporal variations and spatial heterogeneity. The vertical migration process of Pb in April 1988 included a drifting process from the southwest to the north by means of the marine current was rapid in this region. The vertical migration process of Pb in July 1988 in the open waters included no drifting process since the flow rate of marine current was relative low in this region. The vertical migration process of Pb was jointly determined by vertical water’s effect, source input and water exchange, and the influence of marine current on the vertical migration of Pb in marine bay was significant.

On the predictability of high water level along the US East Coast: can the Florida Current measurement be an indicator for flooding caused by remote forcing?

NASA Astrophysics Data System (ADS)

Ezer, Tal; Atkinson, Larry P.

2017-06-01

Recent studies show that in addition to wind and air pressure effects, a significant portion of the variability of coastal sea level (CSL) along the US East Coast can be attributed to non-local factors such as variations in the Gulf Stream and the North Atlantic circulation; these variations can cause unpredictable coastal flooding. The Florida Current transport (FCT) measurement across the Florida Straits monitors those variations, and thus, the study evaluated the potential of using the FCT as an indicator for anomalously high water level along the coast. Hourly water level data from 12 tide gauge stations over 12 years are used to construct records of maximum daily water levels (MDWL) that are compared with the daily FCT data. An empirical mode decomposition (EMD) approach is used to divide the data into high-frequency modes (periods T < ˜30 days), middle-frequency modes (˜30 days < T < ˜90 days), and low-frequency modes (˜90 days < T < ˜1 year). Two predictive measures are tested: FCT and FCT change (FCC). FCT is anti-correlated with MDWL in high-frequency modes but positively correlated with MDWL in low-frequency modes. FCC on the other hand is always anti-correlated with MDWL for all frequency bands, and the high water signal lags behind FCC for almost all stations, thus providing a potential predictive skill (i.e., whenever a weakening trend is detected in the FCT, anomalously high water is expected along the coast over the next few days). The MDWL-FCT correlation in the high-frequency modes is maximum in the lower Mid-Atlantic Bight, suggesting influence from the meandering Gulf Stream after it separates from the coast. However, the correlation in low-frequency modes is maximum in the South Atlantic Bight, suggesting impact from variations in the wind pattern over subtropical regions. The middle-frequency and low-frequency modes of the FCT seem to provide the best predictor for medium to large flooding events; it is estimated that ˜10-25% of the sea level variability in those modes can be attributed to variations in the FCT. An example from Hurricane Joaquin (September-October, 2015) demonstrates how an offshore storm that never made landfall can cause a weakening of the FCT and unexpected high water level and flooding along the US East Coast. A regression-prediction model based on the MDWL-FCT correlation shows some skill in estimating high water levels during past storms; the water level prediction is more accurate for slow-moving and offshore storms than it is for fast-moving storms. The study can help to improve water level prediction since current storm surge models rely on local wind but may ignore remote forcing.

7 CFR 14.6 - Criteria for determining the pri- mary purpose of payments with respect to potential exclusion...

Code of Federal Regulations, 2010 CFR

2010-01-01

... conservation includes actions that, for a given level of water supply, reduce the demand for or use of water by... reuse of water, thereby making existing supplies available for other current or future uses; or (iv) Improving land management practices for the purpose of reducing water use, loss, waste, increasing the...

Bearing the Cost: An Examination of the Gendered Impacts of Water Policy Reform in Malawi

ERIC Educational Resources Information Center

Marra, Simona

2008-01-01

Water insecurity is one of the most pressing issues currently faced by Malawi. The consequences of these issues are borne significantly by women, who are most directly involved with water provision and use, particularly at the household level. Since the mid-1990s, Malawi has undertaken a process of water policy reform. Reflective of international…

Migration of the FDNPP-derived 134Cs and 137Cs along with 226Ra and 228Ra concentrations across the northwestern North Pacific Ocean.

PubMed

Inoue, M; Shirotani, Y; Nagao, S; Kofuji, H; Volkov, Y N; Nishioka, J

2016-10-01

We examined lateral distributions of 134 Cs, 137 Cs, 226 Ra, and 228 Ra in the surface seawaters around the Kuril Islands and the Kamchatka Peninsula in the northwestern North Pacific Ocean during June 2014. The sampling area included three water current areas, the Oyashio Current, the current from the Okhotsk Sea, and the coastal current along the east Kamchatka Peninsula. 226 Ra and 228 Ra distributions differed along the three currents. Low levels of 134 Cs were detected in the surface waters of the Oyashio Current (0.09-0.35 mBq/L), but it was <∼0.1 mBq/L at the surface along the other two currents. This indicates that the distribution of Fukushima Dai-ichi Nuclear Power Plant (FDNPP)-derived radiocesium in surface waters off the Kamchatka and along the Kuril Islands is predominantly governed by the Oyashio current system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Circulation and sedimentation in a tidal-influenced fjord lake: Lake McKerrow, New Zealand

NASA Astrophysics Data System (ADS)

Pickrill, R. A.; Irwin, J.; Shakespeare, B. S.

1981-01-01

Lake McKerrow is a tide-influenced fjord lake, separated from the open sea by a Holocene barrier spit. Fresh, oxygenated waters of the epilimnion overlie saline, deoxygenated waters of the hypolimnion. During winter, water from the Upper Hollyford River interflows along the pycnocline, depositing coarse silt on the steep delta and transporting finer sediment down-lake. An extensive sub-lacustrine channel system on the foreset delta slope is possibly maintained by turbidity currents. Saline waters of the hypolimnion are periodically replenished. During high tides and low lake levels saline water flows into the lake and downslope into the lake basin as a density current in a well defined channel.

Selected Ground-Water Data for Yucca Mountain Region, Southern Nevada and Eastern California, Through December 1992

USGS Publications Warehouse

La Camera, Richard J.; Westenburg, Craig L.

1994-01-01

Tne U.S. Geological Survey. in support of the U.S. Department of Energy, Yucca Mountain Site- Characterization Project, collects, compiles, and summarizes water-resource data in the Yucca Mountain region. The data are collected to document the historical and current condition of ground-water resources, to detect and document changes in those resources through time, and to allow assessments of ground-water resources during investigations to determine the potential suitability of Yucca Mountain for storing high-level nuclear waste. Data on ground-water levels at 36 sites, ground- water discharge at 6 sites, ground-water quality at 19 sites, and ground-water withdrawals within Crater Fiat, Jackass Flats, Mercury Valley, and the Amargosa Desert are presented. Data on ground-water levels, discharges, and withdrawals collected by other agencies or as part of other programs are included to further indicate variations through time. A statistical summary of ground-water levels and median annual ground-water withdrawals in Jackass Flats is presented. The statistical summary includes the number of measurements, the maximum, minimum, and median water-level altitudes, and the average deviation of a11 water-level altitudes for selected baseline periods and for calendar year 1992. Data on ground-water quality are compared to established, proposed, or tentative primary and secondary drinking-water standards, and measures which exceeded those standards are listed for 18 sites. Detected organic compounds for which established, proposed, or tentative drinking-water standards exist also are listed.

Onset and demise of Cretaceous oceanic anoxic events: The coupling of surface and bottom oceanic processes in two pelagic basins of the western Tethys

NASA Astrophysics Data System (ADS)

Gambacorta, G.; Bersezio, R.; Weissert, H.; Erba, E.

2016-06-01

The upper Albian-lower Turonian pelagic successions of the Tethys record processes acting during the onset, core, and recovery from perturbed conditions across oceanic anoxic event (OAE) 1d, OAE 2, and the mid-Cenomanian event I (MCE I) relative to intervening intervals. Five sections from Umbria-Marche and Belluno Basins (Italy) were analyzed at high resolution to assess processes in surface and deep waters. Recurrent facies stacking patterns (SP) and their associations record periods of bottom current activity coupled with surface changes in trophic level. Climate changes appear to have been influential on deep circulation dynamics. Under greenhouse conditions, vigorous bottom currents were arguably induced by warm and dense saline deep waters originated on tropical shelves in the Tethys and/or proto-Atlantic Ocean. Tractive facies postdating intermittent anoxia during OAE 1d and in the interval bracketed by MCE I and OAE 2 are indicative of feeble bottom currents, though capable of disrupting stratification and replenish deep water with oxygen. The major warming at the onset of OAE 2 might have enhanced the formation of warm salty waters, possibly producing local hiatuses at the base of the Bonarelli Level and winnowing at the seafloor. Hiatuses detected at the top of the Bonarelli Level possibly resulted from most effective bottom currents during the early Turonian thermal maximum. Times of minimal sediment displacement correlate with cooler climatic conditions and testify a different mechanism of deep water formation, as further suggested by a color change to reddish lithologies of the post-OAE 1d and post-OAE 2 intervals.

Modeling of water masses exchange between Brepolen and the main fjord in the Western Svalbard fjord - Hornsund

NASA Astrophysics Data System (ADS)

Jakacki, Jaromir; Przyborska, Anna; Sunfjord, Arild; Albertsen, Jon; Białoskórski, Michał; Pliszka, Bartosz

2016-04-01

Hornsund is the southernmost fjord of the Svalbard archipelago island - Spitsbergen. It is under the influence of two main currents - the coastal Sørkapp Current (SC) carrying fresher and colder water masses from the Barents Sea and the West Spitsbergen Current (WSC), which is the branch of the Norwegian Atlantic Current (NwAC) and carries warm and salty waters from the North Atlantic. The main local forcing, which is tidal motion, brings shelf waters into the central fjord basin and then the transformed masses are carried into the easternmost part of the fjord, Brepolen. For the purpose of studying circulation and water exchange in this area a three-dimensional hydrodynamic model has been implemented and validated. The model is based on MIKE by DHI product and covers the Hornsund fjord with the shelf area, which is the fjord foreground. It is sigma a coordinate model (in our case 35 vertical levels) with variable horizontal resolution (mesh grid). The smallest cell has a horizontal dimension less than one hundred meters and the largest cells about 5 km. In spite of model limitations, the model reproduces the main circulation and water pathways in the Brepolen area. Seasonal and annual volume, heat and salt exchanges have been also estimated. The influence of freshwater discharge on shelf-fjord exchange will be also analyzed. The model results allow to study full horizontal and vertical fields of physical parameters (temperature, salinity, sea level variations and currents). The model integration covers only years 2005-2010 and the presented results will be based on this simulation. The project has been financed from the funds of the Leading National Research Centre (KNOW) received by the Centre for Polar Studies for the period 2014-2018

Remediation of water and wastewater by using engineered nanomaterials: A review.

PubMed

Bishoge, Obadia K; Zhang, Lingling; Suntu, Shaldon L; Jin, Hui; Zewde, Abraham A; Qi, Zhongwei

2018-05-12

Nanotechnology is currently a fast-rising socioeconomic and political knowledge-based technology owing to the unique characteristics of its engineered nanomaterials. This branch of technology is useful for water and wastewater remediation. Many scientists and researchers have been conducting different studies and experiments on the applications of engineered nanomaterials at the local to international level. This review mainly aims to provide a current overview of existing knowledge on engineered nanomaterials and their applications in water and wastewater remediation. Furthermore, the present risks and challenges of nanotechnology are examined.

Large-scale forcing of the European Slope Current and associated inflows to the North Sea

NASA Astrophysics Data System (ADS)

Marsh, Robert; Haigh, Ivan D.; Cunningham, Stuart A.; Inall, Mark E.; Porter, Marie; Moat, Ben I.

2017-04-01

The European Slope Current provides a shelf-edge conduit for Atlantic Water, a substantial fraction of which is destined for the northern North Sea, with implications for regional hydrography and ecosystems. Drifters drogued at 50 m in the European Slope Current at the Hebridean shelf break follow a wide range of pathways, indicating highly variable Atlantic inflow to the North Sea. Slope Current pathways, timescales and transports over 1988-2007 are further quantified in an eddy-resolving ocean model hindcast. Particle trajectories calculated with model currents indicate that Slope Current water is largely recruited from the eastern subpolar North Atlantic. Observations of absolute dynamic topography and climatological density support theoretical expectations that Slope Current transport is to first order associated with meridional density gradients in the eastern subpolar gyre, which support a geostrophic inflow towards the slope. In the model hindcast, Slope Current transport variability is dominated by abrupt 25-50 % reductions of these density gradients over 1996-1998. Concurrent changes in wind forcing, expressed in terms of density gradients, act in the same sense to reduce Slope Current transport. This indicates that coordinated regional changes of buoyancy and wind forcing acted together to reduce Slope Current transport during the 1990s. Particle trajectories further show that 10-40 % of Slope Current water is destined for the northern North Sea within 6 months of passing to the west of Scotland, with a general decline in this percentage over 1988-2007. Salinities in the Slope Current correspondingly decreased, evidenced in ocean analysis data. Further to the north, in the Atlantic Water conveyed by the Slope Current through the Faroe-Shetland Channel (FSC), salinity is observed to increase over this period while declining in the hindcast. The observed trend may have broadly compensated for a decline in the Atlantic inflow, limiting salinity changes in the northern North Sea during this period. Proxies for both Slope Current transport and Atlantic inflow to the North Sea are sought in sea level height differences across the FSC and between Shetland and the Scottish mainland (Wick). Variability of Slope Current transport on a wide range of timescales, from seasonal to multi-decadal, is implicit in sea level differences between Lerwick (Shetland) and Tórshavn (Faroes), in both tide gauge records from 1957 and a longer model hindcast spanning 1958-2012. Wick-Lerwick sea level differences in tide gauge records from 1965 indicate considerable decadal variability in the Fair Isle Current transport that dominates Atlantic inflow to the northwest North Sea, while sea level differences in the hindcast are dominated by strong seasonal variability. Uncertainties in the Wick tide gauge record limit confidence in this proxy.

ATRAZINE ECOLOGICAL EFFECTS ASSESSMENT FOR OPP LEVEL OF CONCERN AND OW WATER QUALITY CRITERION FOR AQUATIC LIFE

EPA Science Inventory

Atrazine is a relatively water-soluble and persistent herbicide that can reach concentrations of possible ecological concern for aquatic plants in vulnerable watersheds in regions with high agricultural usage of atrazine. As a consequence, the U.S. EPA Office of Water is current...

Kansas ground-water observation-well network, 1985

USGS Publications Warehouse

Dague, B.J.; Stullken, L.E.

1986-01-01

Water level measurements are made in 1,892 selected wells in 73 counties, which currently (1985) comprise the Kansas groundwater observation-well network. These measurements are made on a continuous, monthly, quarterly, or annual basis. Water level measurements have been made in observation wells since 1937 as part of a cooperative program among the Kansas Geological Survey , the Kansas State Board of Agriculture, the city of Wichita, and the U.S. Geological Survey. The objectives of the observation-well cooperative program are: (1) to provide long-term records of water level fluctuations in representative wells, (2) to facilitate the determination of possible water level trends that may indicate future availability of groundwater supplies, (3) to aid in the determination of possible changes in the base flow of streams, and (4) to provide information for use in water-resources research. This report lists for each well in the network the location, the first year of recorded water level measurement, the frequency and number of measurements, the land-surface altitude, hexagon-grid identifiers for wells in the High Plains aquifer, and the principal geologic unit(s) in which the well is completed. (USGS)

Assessing health risk due to exposure to arsenic in drinking water in Hanam Province, Vietnam.

PubMed

Huy, Tung Bui; Tuyet-Hanh, Tran Thi; Johnston, Richard; Nguyen-Viet, Hung

2014-07-24

We assessed health risks related to Arsenic (As) in contaminated drinking water in Hanam, applying the Australian Environmental Health Risk Assessment Framework, which promotes stakeholder involvement in risk assessments. As concentrations in 300 tube-well water samples, before and after filtration, were analyzed and the water consumption levels in 150 households were estimated. Skin cancer risk was characterized using Cancer Slope Factor index and lifetime average daily dose with a probabilistic approach. The results showed that arsenic concentrations in tube-well water ranged from 8-579 ppb (mean 301 ppb) before filtration and current sand filters used by the households did not meet the standard for As removal. Arsenic daily consumption of 40% of the adults exceeded the level of TDI (Tolerable Daily Intake) at 1 µg/kg/day. The average skin cancer risk in adults due to consuming filtered tube-well water for drinking purpose were 25.3 × 10-5 (using only well water) and 7.6 × 10-5 (using both well and rain water). The skin cancer risk would be 11.5 times higher if the water was not filtered. Improvement of filtration measures or the replacement of the current drinking water sources to minimize the health risks to the local population is urgently needed.

Assessing Health Risk due to Exposure to Arsenic in Drinking Water in Hanam Province, Vietnam

PubMed Central

Bui Huy, Tung; Tuyet-Hanh, Tran Thi; Johnston, Richard; Nguyen-Viet, Hung

2014-01-01

We assessed health risks related to Arsenic (As) in contaminated drinking water in Hanam, applying the Australian Environmental Health Risk Assessment Framework, which promotes stakeholder involvement in risk assessments. As concentrations in 300 tube-well water samples, before and after filtration, were analyzed and the water consumption levels in 150 households were estimated. Skin cancer risk was characterized using Cancer Slope Factor index and lifetime average daily dose with a probabilistic approach. The results showed that arsenic concentrations in tube-well water ranged from 8–579 ppb (mean 301 ppb) before filtration and current sand filters used by the households did not meet the standard for As removal. Arsenic daily consumption of 40% of the adults exceeded the level of TDI (Tolerable Daily Intake) at 1 µg/kg/day. The average skin cancer risk in adults due to consuming filtered tube-well water for drinking purpose were 25.3 × 10−5 (using only well water) and 7.6 × 10−5 (using both well and rain water). The skin cancer risk would be 11.5 times higher if the water was not filtered. Improvement of filtration measures or the replacement of the current drinking water sources to minimize the health risks to the local population is urgently needed. PMID:25062276

Analysis of the Impact of Realistic Wind Size Parameter on the Delft3D Model

NASA Astrophysics Data System (ADS)

Washington, M. H.; Kumar, S.

2017-12-01

The wind size parameter, which is the distance from the center of the storm to the location of the maximum winds, is currently a constant in the Delft3D model. As a result, the Delft3D model's output prediction of the water levels during a storm surge are inaccurate compared to the observed data. To address these issues, an algorithm to calculate a realistic wind size parameter for a given hurricane was designed and implemented using the observed water-level data for Hurricane Matthew. A performance evaluation experiment was conducted to demonstrate the accuracy of the model's prediction of water levels using the realistic wind size input parameter compared to the default constant wind size parameter for Hurricane Matthew, with the water level data observed from October 4th, 2016 to October 9th, 2016 from National Oceanic and Atmospheric Administration (NOAA) as a baseline. The experimental results demonstrate that the Delft3D water level output for the realistic wind size parameter, compared to the default constant size parameter, matches more accurately with the NOAA reference water level data.

Sensitivity of Water-Energy Nexus to dam operation: A Water-Energy Productivity concept.

PubMed

Basheer, Mohammed; Elagib, Nadir Ahmed

2018-03-01

Understanding and modelling the complex nature of interlinkages between water and energy are essential for efficient use of the two resources. Hydropower storage dams represent an interesting example of the water-energy interdependencies since they are often multipurpose. The concept of Water-Energy Productivity (WEP), defined as the amount of energy produced per unit of water lost in the process, is introduced in this study to illustrate the relationship between energy generation and water losses by examining the sensitivity of the Water-Energy Nexus (WEN) to changing dam operation policy. This concept is demonstrated by developing a water allocation model of the White Nile in Sudan, including Jebel Aulia Dam (JAD), using a general river and reservoir simulation software called RiverWare. A number of 77 operation scenarios of JAD are examined for 30 hydrologic years (1980-2009), considering reducing the Full Supply Level (FSL) gradually from its current value to the minimum possible value, increasing the Minimum Operating Level (MOL) gradually to the maximum possible level, and operating the dam at a Constant Operating Level (COL). The results show that raising the operating level does not necessarily increase the WEP. In comparison to the current policy, the analysis shows that a maximum WEP of 32.6GWh/BCM (GWh/Billion Cubic Meters) would be reached by raising the MOL to 375masl (meters above sea level), resulting in an increase in average annual energy generation to 164.6GWh (+18.1%) at the expense of an annual water loss of 5.05BCM (+12.7%). Even though this operation policy results in a more efficient water use compared to the original operation policy, a basin-wide assessment that includes all hydropower storage dams in the Nile basin should be conducted to decide on where and how much energy should be generated. The present analysis and future examination of the multi-dimensions of the WEN in the context of dam operation are imperative to improve the decision making in the quest for efficient resource use and management. Copyright © 2017 Elsevier B.V. All rights reserved.

Ground-Water Occurrence and Movement, 2006, and Water-Level Changes in the Detrital, Hualapai, and Sacramento Valley Basins, Mohave County, Arizona

USGS Publications Warehouse

Anning, David W.; Truini, Margot; Flynn, Marilyn E.; Remick, William H.

2007-01-01

Ground-water levels for water year 2006 and their change over time in Detrital, Hualapai, and Sacramento Valley Basins of northwestern Arizona were investigated to improve the understanding of current and past ground-water conditions in these basins. The potentiometric surface for ground water in the Basin-Fill aquifer of each basin is generally parallel to topography. Consequently, ground-water movement is generally from the mountain front toward the basin center and then along the basin axis toward the Colorado River or Lake Mead. Observed water levels in Detrital, Hualapai, and Sacramento Valley Basins have fluctuated during the period of historic water-level records (1943 through 2006). In Detrital Valley Basin, water levels in monitored areas have either remained the same, or have steadily increased as much as 3.5 feet since the 1980s. Similar steady conditions or water-level rises were observed for much of the northern and central parts of Hualapai Valley Basin. During the period of historic record, steady water-level declines as large as 60 feet were found in wells penetrating the Basin-Fill aquifer in areas near Kingman, northwest of Hackberry, and northeast of Dolan Springs within the Hualapai Valley Basin. Within the Sacramento Valley Basin, during the period of historic record, water-level declines as large as 55 feet were observed in wells penetrating the Basin-Fill aquifer in the Kingman and Golden Valley areas; whereas small, steady rises were observed in Yucca and in the Dutch Flat area.

Occurrence assessment for disinfectants and disinfection by-products (phase 6A) in public drinking water. Final report

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

Not Available

The EPA Office of Ground Water and Drinking Water is developing national primary drinking water regulations for disinfectant and disinfection by-product contaminants. Thirteen contaminants are being considered to be regulated under Phase 6. These contaminants, referred to as Phase 6a, are the subject of the report. The information is important for setting the Maximum Contaminant Level Goal for a contaminant. The exposure information also is used to estimate the baseline health impact assessment of current levels and for evaluation of the health benefits of the regulatory alternatives.

Growth of a deep-water, predatory fish is influenced by the productivity of a boundary current system

PubMed Central

Nguyen, Hoang Minh; Rountrey, Adam N.; Meeuwig, Jessica J.; Coulson, Peter G.; Feng, Ming; Newman, Stephen J.; Waite, Anya M.; Wakefield, Corey B.; Meekan, Mark G.

2015-01-01

The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p < 0.02) with sea level at Fremantle, a proxy for the strength of the Leeuwin Current. The Leeuwin Current influences the primary productivity of shelf ecosystems, with a strong current favouring growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats. PMID:25761975

Growth of a deep-water, predatory fish is influenced by the productivity of a boundary current system.

PubMed

Nguyen, Hoang Minh; Rountrey, Adam N; Meeuwig, Jessica J; Coulson, Peter G; Feng, Ming; Newman, Stephen J; Waite, Anya M; Wakefield, Corey B; Meekan, Mark G

2015-03-12

The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p < 0.02) with sea level at Fremantle, a proxy for the strength of the Leeuwin Current. The Leeuwin Current influences the primary productivity of shelf ecosystems, with a strong current favouring growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats.

Summary of the Ground-Water-Level Hydrologic Conditions in New Jersey 2006

USGS Publications Warehouse

Jones, Walter; Pope, Daryll

2007-01-01

Ground water is one of the Nation's most important natural resources. It provides about 40 percent of our Nation's public water supply. Currently, nearly one-half of New Jersey's drinking-water is supplied by over 300,000 wells that serve more than 4.3 million people (John P. Nawyn, U.S. Geological Survey, written commun., 2007). New Jersey's population is projected to grow by more than a million people by 2030 (U.S. Census Bureau, accessed March 2, 2006, at http://www.census.gov). As demand for water increases, managing the development and use of the ground-water resource so that the supply can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences is of paramount importance. This report describes the U.S. Geological Survey (USGS) New Jersey Water Science Center Observation Well Networks. Record low ground-water levels during water year 2006 (October 1, 2005 to September 30, 2006) are listed, and water levels in six selected water-table observation wells and three selected confined wells are shown in hydrographs. The report describes the trends in water levels in various confined aquifers in southern New Jersey and in water-table and fracture rock aquifers throughout the State. Web site addresses to access the data also are included. The USGS has operated a network of observation wells in New Jersey since 1923 for the purpose of monitoring ground-water-level changes throughout the State. Long-term systematic measurement of water levels in observation wells provides the data needed to evaluate changes in the ground-water resource over time. Records of ground-water levels are used to evaluate the effects of climate changes and water-supply development, to develop ground-water models, and to forecast trends.

PAIRED-CITY STUDY TO DETERMINE THE CONTRIBUTION OF SOURCE WATER TYPE TO THE ENDEMIC LEVEL OF MICROBIAL DISEASE

EPA Science Inventory

Paired-City Study to Determine the Contribution of Source Water Type to the Endemic Level of Microbial Disease

F Frost PhD, T Kunde MPH, L Harter PhD, T Muller MS, GF Craun PE MPH, RL Calderon MPH PhD

ABSTRACT

Context: The effectiveness of current drinking...

Declining groundwater level caused by irrigation to row crops in the Lower Mississippi River Basin, Current Situation and Trends

NASA Astrophysics Data System (ADS)

Feng, G.; Gao, F.; Ouyang, Y.

2017-12-01

The Mississippi River is North America's largest river and the second largest watershed in the world. It flows over 3,700 km through America's heartland to the Gulf of Mexico. Over 3 million hectares in the Lower Mississippi River Basin represent irrigated cropland and 90 percent of those lands currently rely on the groundwater supply. The primary crops grown in this region are soybean, corn, cotton, and rice. Increased water withdrawals for irrigating those crops and stagnant recharging jeopardize the long-term availability of the aquifer and place irrigation agriculture in the region on an unsustainable path. The objectives of this study were to: 1) analyze the current groundwater level in the Lower Mississippi River Basin based on the water table depth observed by Yazoo Mississippi Delta Joint Water Management District from 2000 and 2016; 2) determine trends of change in groundwater level under conventional and groundwater saving irrigation management practices (ET or soil moisture based full irrigation scheduling using all groundwater or different percentages of ground and surface water). The coupled SWAT and MODFLOW model was applied to investigate the trends. Observed results showed that the groundwater level has declined from 33 to 26 m at an annual decrease rate of 0.4 m in the past 17 years. Simulated results revealed that the groundwater storage was decreased by 26 cm/month due to irrigation in crop season. It is promising that the groundwater storage was increased by 23 cm/month, sometimes even 60 cm/month in crop off-growing season because of recharge from rainfall. Our results suggest that alternative ET or soil moisture based groundwater saving irrigation scheduling with conjunctive use of surface water is a sustainable practice for irrigated agriculture in in the Lower Mississippi River Basin.

Red Sea Intermediate Water at the Agulhas Current termination

NASA Astrophysics Data System (ADS)

Roman, R. E.; Lutjeharms, J. R. E.

2007-08-01

The inter-ocean exchange of water masses at the Agulhas Current termination comes about through the shedding of rings, and this process plays an important role in the global thermohaline circulation. Using several hydrographic sections collected during the ARC (Agulhas Retroflection Cruise), MARE (Mixing of Agulhas Rings Experiment) and WOCE (World Ocean Circulation Experiment), this investigation aims to establish the degree to which Red Sea Intermediate Water (RSIW) is involved in this exchange and at what level of purity. To this end a wide range of hydrographic parameters were used. Upstream from the Agulhas Current retroflection water with clear RSIW origin is shown to move downstream on both the landward and seaward sides of the Agulhas Current with the highest water sample purity or water-mass content exceeding 15%. The least mixed water was found close to the continental shelf. At the retroflection the RSIW purity shows considerable variability that ranges between 5% and 20%. This suggests that RSIW moves down the current in patches of considerably varying degrees of previous mixing. This pattern was also observed in a ring sampled during the ARC experiment. The MARE sections in turn indicate that at times RSIW may be entirely absent in the Agulhas Current. RSIW is therefore shown to travel down the current as discontinuous filaments, and this intermittency is reflected in its presence in Agulhas Rings. From the sections investigated it is therefore clear that any calculation of RSIW fluxes involved in inter-ocean exchange can only be done on the basis of event scales. RSIW not trapped in Agulhas Rings flows east with the Agulhas Return Current.

Climate Sensitivity Runs and Regional Hydrologic Modeling for Predicting the Response of the Greater Florida Everglades Ecosystem to Climate Change

NASA Astrophysics Data System (ADS)

Obeysekera, Jayantha; Barnes, Jenifer; Nungesser, Martha

2015-04-01

It is important to understand the vulnerability of the water management system in south Florida and to determine the resilience and robustness of greater Everglades restoration plans under future climate change. The current climate models, at both global and regional scales, are not ready to deliver specific climatic datasets for water resources investigations involving future plans and therefore a scenario based approach was adopted for this first study in restoration planning. We focused on the general implications of potential changes in future temperature and associated changes in evapotranspiration, precipitation, and sea levels at the regional boundary. From these, we developed a set of six climate and sea level scenarios, used them to simulate the hydrologic response of the greater Everglades region including agricultural, urban, and natural areas, and compared the results to those from a base run of current conditions. The scenarios included a 1.5 °C increase in temperature, ±10 % change in precipitation, and a 0.46 m (1.5 feet) increase in sea level for the 50-year planning horizon. The results suggested that, depending on the rainfall and temperature scenario, there would be significant changes in water budgets, ecosystem performance, and in water supply demands met. The increased sea level scenarios also show that the ground water levels would increase significantly with associated implications for flood protection in the urbanized areas of southeastern Florida.

Cold Front Driven Flows Through Multiple Inlets of Lake Pontchartrain Estuary

NASA Astrophysics Data System (ADS)

Huang, Wei; Li, Chunyan

2017-11-01

With in situ observations using acoustic Doppler current profilers (ADCPs) and numerical experiments using the Finite Volume Coastal Ocean Model (FVCOM), this study investigates atmospheric cold front induced exchange of water between Lake Pontchartrain Estuary and coastal ocean through multiple inlets. Results show that the subtidal hydrodynamic response is highly correlated with meteorological parameters. Northerly and westerly winds tend to push water out of Lake Pontchartrain, while south and east winds tend to produce currents flowing into it. For most cases, the subtidal water level is inversely correlated with the east wind, with the correlation coefficient being ˜0.8. The most important finding of this work is that, contrary to intuition, the cold front induced remote wind effect has the greatest contribution to the overall water level variation, while the local wind stress determines the surface slope inside the estuary. It is found that wind driven flow is roughly quasi steady state: the surface slope in the north-south direction is determined by the north-south wind stress, explaining ˜83% of the variability but less so in the east-west direction (˜43%). In other words, the north-south local wind stress determines the water level gradient in that direction in the estuary while the overall water level change is pretty much controlled by the open boundary which is the "remote wind effect," a regional response that can be illustrated only by a numerical model for a much larger area encompassing the estuary.

Coastal Circulation and Sediment Dynamics in Hanalei Bay, Kaua'i, Part IV, Measurements of Waves, Currents, Temperature, Salinity, and Turbidity, June-September 2006

USGS Publications Warehouse

Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

2008-01-01

High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Hanalei Bay, northern Kaua'i, Hawai'i, during the summer of 2006 to better understand coastal circulation, sediment dynamics, and the potential impact of a river flood in a coral reef-lined embayment during quiescent summer conditions. A series of bottommounted instrument packages were deployed in water depths of 10 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water column properties within the bay. These measurements support the ongoing process studies being conducted as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Information regarding the USGS study conducted in Hanalei Bay during the 2005 summer is available in Storlazzi and others (2006), Draut and others (2006) and Carr and others (2006). This report, the last part in a series, describes data acquisition, processing, and analysis for the 2006 summer data set.

Estimation of Missing Water-Level Data for the Everglades Depth Estimation Network (EDEN)

USGS Publications Warehouse

Conrads, Paul; Petkewich, Matthew D.

2009-01-01

The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level gaging stations, ground-elevation models, and water-surface elevation models designed to provide scientists, engineers, and water-resource managers with current (2000-2009) water-depth information for the entire freshwater portion of the greater Everglades. The U.S. Geological Survey Greater Everglades Priority Ecosystems Science provides support for EDEN and their goal of providing quality-assured monitoring data for the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan. To increase the accuracy of the daily water-surface elevation model, water-level estimation equations were developed to fill missing data. To minimize the occurrences of no estimation of data due to missing data for an input station, a minimum of three linear regression equations were developed for each station using different input stations. Of the 726 water-level estimation equations developed to fill missing data at 239 stations, more than 60 percent of the equations have coefficients of determination greater than 0.90, and 92 percent have an coefficient of determination greater than 0.70.

Geophysical investigation of Red Devil mine using direct-current resistivity and electromagnetic induction, Red Devil, Alaska, August 2010

USGS Publications Warehouse

Burton, Bethany L.; Ball, Lyndsay B.

2011-01-01

Red Devil Mine, located in southwestern Alaska near the Village of Red Devil, was the state's largest producer of mercury and operated from 1933 to 1971. Throughout the lifespan of the mine, various generations of mills and retort buildings existed on both sides of Red Devil Creek, and the tailings and waste rock were deposited across the site. The mine was located on public Bureau of Land Management property, and the Bureau has begun site remediation by addressing mercury, arsenic, and antimony contamination caused by the minerals associated with the ore deposit (cinnabar, stibnite, realgar, and orpiment). In August 2010, the U.S. Geological Survey completed a geophysical survey at the site using direct-current resistivity and electromagnetic induction surface methods. Eight two-dimensional profiles and one three-dimensional grid of direct-current resistivity data as well as about 5.7 kilometers of electromagnetic induction profile data were acquired across the site. On the basis of the geophysical data and few available soil borings, there is not sufficient electrical or electromagnetic contrast to confidently distinguish between tailings, waste rock, and weathered bedrock. A water table is interpreted along the two-dimensional direct-current resistivity profiles based on correlation with monitoring well water levels and a relatively consistent decrease in resistivity typically at 2-6 meters depth. Three settling ponds used in the last few years of mine operation to capture silt and sand from a flotation ore processing technique possessed conductive values above the interpreted water level but more resistive values below the water level. The cause of the increased resistivity below the water table is unknown, but the increased resistivity may indicate that a secondary mechanism is affecting the resistivity structure under these ponds if the depth of the ponds is expected to extend below the water level. The electromagnetic induction data clearly identified the three monofills and indicate, in conjunction with the three-dimensional resistivity data, additional possible landfill features on the north side of Red Devil Creek. No obvious shallow feature was identified as a possible source for a spring that is feeding into Red Devil Creek from the north bank. However, a discrete, nearly vertical conductive feature observed on the direct-current resistivity line that passes within 5 meters of the spring may be worth investigating. Additional deep soil borings that better differentiate between tailings, waste rock, and weathered bedrock may be very useful in more confidently identifying these rock types in the direct-current resistivity data.

Stray voltage and milk quality: a review.

PubMed

Reinemann, Douglas J

2012-07-01

If animal contact voltage reaches sufficient levels, animals coming into contact with grounded devices may receive a mild electric shock that can cause a behavioral response. At voltage levels that are just perceptible to the animal, behaviors indicative of perception (eg, flinches) may result with little change in normal routines. At higher exposure levels, avoidance behaviors may result. The direct effect of animal contact with electrical current can range from: • Mild behavioral reactions indicative of sensation, to • Involuntary muscle contraction, or twitching, to • Intense behavioral responses indicative of pain. The indirect effects of these behaviors can vary considerably depending on the specifics of the contact location, level of current flow, body pathway, frequency of occurrence, and many other factors related to the daily activities of animals. There are several common situations of concern in animal environments: • Animals avoiding certain exposure locations, which may result in: X Reduced water intake if exposure is required for animals to access watering devices, X Reduced feed intake if exposure is required for animals to accesses feeding devices or locations. • Difficulty of moving or handling animals in areas of voltage/current exposure• The physiologic implications of the release of stress hormones produced by contact with painful stimuli. The severity of response will depend on the amount of electrical current (measured in milliamps) flowing through the animal’s body, the pathway it takes through the body, and the sensitivity of the individual animal. The results of the combined current dose-response experiments, voltage exposure response experiments, and measurements of body and contact resistances is consistent with the lowest (worst case) cow + contact resistance as low as 500 as estimated by Lefcourt that may occur in some unusual situations on farms (firm application of the muzzle to a wet metallic watering device and hoof contact on a clean, wet, contoured metallic plate on the floor). These studies on responses of dairy cows to electrical exposure agree well with each other and with predictions from neuroelectric theory and practice. There is a high degree of repeatability across studies in which exposures and responses have been appropriately quantified. For confirmation, a potential of 2 to 4 V (60 Hz, rms) must be measured between 2 points that an animal might contact (or animal contact measurement), and some animals should exhibit signs of avoidance behavior. The animal contact voltage measurement with an appropriate shunt resistor value provides the only reliable indication of exposure levels. Voltage readings at cow contact points should be made with a 500- or 1000- resistor across the 2 measuring leads to the cow contact points in addition to open circuit measurements. The only studies that have documented adverse effects of voltage and current on cows had both sufficient current applied to cause aversion and forced exposures (ie, animals could not eat or drink without being exposed to voltage and current) and all of the indirect responses (reduced water or intake and milk production) were behaviorally mediated. It is typical for voltage levels to vary considerably at different locations on a farm. Decreased water and/or feed intake or undesired behaviors result only if current levels are sufficient to produce aversion at locations that are critical to daily animal activity, such as feeders, waterers, and milking areas. If an aversive current occurs only a few times per day, it is not likely to have an adverse effect on cow behavior. The more often an aversive voltage occurs in areas critical to cows’ normal feeding, drinking, or resting, the more likely it is to affect cows. A number of studies have been done to investigate potential detrimental physiologic responses that may result from animals’ exposure to voltage and current. The literature review presented here summarizes 46 research trials on groups of cows exposed to know levels of voltage and/or current. Many of these were part of the same experiment but exposed cows at different levels of voltage or current. None of these trials or experiments (some using aggressive exposure of cows to mastitis organisms) showed a significant effect of voltage/current exposure on SCC or the incidence of mastitis. Many of these studies showed behavioral modification and some showed minor changes in milk yield, milk composition, or stress hormones (especially cortisol). These studies have shown that increased concentrations of the stress hormone cortisol do not occur at levels below behavioral response levels and only become apparent in some, but not all, cows at substantially higher voltage/current exposures than the threshold required for behavioral modification. This body of research indicates that while exposure to stray voltage at levels of 2 V to 4 V may be a mild stressor to dairy cows, it does not contribute to increased SCC or incidence of mastitis or reduced milk yield.

[Arsenic levels in drinking water supplies from underground sources in the community of Madrid].

PubMed

Aragonés Sanz, N; Palacios Diez, M; Avello de Miguel, A; Gómez Rodríguez, P; Martínez Cortés, M; Rodríguez Bernabeu, M J

2001-01-01

In 1998, arsenic concentrations of more than 50 micrograms/l were detected in some drinking water supplies from underground sources in the Autonomous Community of Madrid, which is the maximum permissible concentration for drinking water in Spain. These two facts have meant the getting under way of a specific plan for monitoring arsenic in the drinking water in the Autonomous Community of Madrid. The results of the first two sampling processes conducted in the arsenic level monitoring plan set out are presented. In the initial phase, water samples from 353 water supplies comprised within the census of the Public Health Administration of the Autonomous Community of Madrid were analyzed. A water supply risk classification was made based on these initial results. In a second phase, six months later, the analyses were repeated on those 35 water supplies which were considered to possibly pose a risk to public health. Seventy-four percent (74%) of the water supplies studied in the initial phase were revealed to have an arsenic concentration of less than 10 micrograms/l, 22.6% containing levels of 10 micrograms/l-50 micrograms/l, and 3.7% over 50 micrograms/l. Most of the water supplies showing arsenic levels of more than 10 micrograms/l are located in the same geographical area. In the second sampling process (six months later), the 35 water supplies classified as posing a risk were included. Twenty-six (26) of these supplies were revealed to have the same arsenic level ((10-50 micrograms/l), and nine changed category, six of which had less than 10 micrograms/l and three more than 50 micrograms/l. In the Autonomous Community of Madrid, less than 2% of the population drinks water coming from supplies which are from underground sources. The regular water quality monitoring conducted by the Public Health Administration has led to detecting the presence of more than 50 micrograms/l of arsenic in sixteen drinking water supplies from underground sources, which is the maximum permissible level under the laws currently in force in Spain. Measures have been taken to prevent water from being used from these water supplies. Around 20% of the water supplies studies must take measures in the near future to lower the arsenic concentration to below 10 micrograms/l when the water directive which is currently in the process of being written into Spanish law enters into effect.

Concentration and Quantification of Somatic and F+ Coliphage from Recreational Waters

EPA Science Inventory

Somatic and F+ coliphages are promising alternative fecal indicators, but current detection methods are hindered by lower levels of coliphages in surface waters compared to traditional bacterial fecal indicators. We evaluated the ability of dead-end hollow fiber ultrafiltration (...

REMOVAL OF URANIUM FROM DRINKING WATER BY CONVENTIONAL TREATMENT METHODS

EPA Science Inventory

The USEPA currently does not regulate uranium in drinking water but will be revising the radionuclide regulations during 1989 and will propose a maximum contaminant level for uranium. The paper presents treatment technology information on the effectiveness of conventional method...

Water management in a planar air-breathing fuel cell array using operando neutron imaging

NASA Astrophysics Data System (ADS)

Coz, E.; Théry, J.; Boillat, P.; Faucheux, V.; Alincant, D.; Capron, P.; Gébel, G.

2016-11-01

Operando Neutron imaging is used for the investigation of a planar air-breathing array comprising multiple cells in series. The fuel cell demonstrates a stable power density level of 150 mW/cm2. Water distribution and quantification is carried out at different operating points. Drying at high current density is observed and correlated to self-heating and natural convection. Working in dead-end mode, water accumulation at lower current density is largely observed on the anode side. However, flooding mechanisms are found to begin with water condensation on the cathode side, leading to back-diffusion and anodic flooding. Specific in-plane and through-plane water distribution is observed and linked to the planar array design.

North-South Partnership in Water Resource Education and Research - Lessons learnt from U.S.-Ethiopia Partnership

NASA Astrophysics Data System (ADS)

Gebremichael, M.

2015-12-01

In 2010, Ethiopian and U.S. universities formed partnership to train critical mass of Ethiopians in modern water resources tools, techniques, skills and knowledge, and to strengthen the institutional capacity of Ethiopian universities to establish graduate-level programs in Ethiopia. The partnership established Ethiopia's first water resource research institute, two graduate-level programs (water resource engineering and management, water and health) that are currently training about 100 students at M.S. and Ph.D. levels, summer undergraduate outreach program that provided community-based research experience in water resource for undergraduate students, and short-term trainings to practitioners and policy makers. The design, implementation and impact of these programs have had limitations and successes. In this presentation, I will provide lessons learnt from this partnership, and suggestions of elements required for successful North-South partnership in higher education and research.

On the dense water spreading off the Ross Sea shelf (Southern Ocean)

NASA Astrophysics Data System (ADS)

Budillon, G.; Gremes Cordero, S.; Salusti, E.

2002-07-01

In this study, current meter and hydrological data obtained during the X Italian Expedition in the Ross Sea (CLIMA Project) are analyzed. Our data show a nice agreement with previous data referring to the water masses present in this area and their dynamics. Here, they are used to further analyze the mixing and deepening processes of Deep Ice Shelf Water (DISW) over the northern shelf break of the Ross Sea. In more detail, our work is focused on the elementary mechanisms that are the most efficient in removing dense water from the shelf: either classical mixing effects or density currents that interact with some topographic irregularity in order to drop to deeper levels, or also the variability of the Antarctic Circumpolar Current (ACC) which, in its meandering, can push the dense water off the shelf, thus interrupting its geostrophic flow. We also discuss in detail the (partial) evidence of dramatic interactions of the dense water with bottom particulate, of geological or biological origin, thus generating impulsive or quasi-steady density-turbidity currents. This complex interaction allows one to consider bottom particular and dense water as a unique self-interacting system. In synthesis, this is a first tentative analysis of the effect of bottom particulate on the dense water dynamics in the Ross Sea.

Observations of currents and density structure across a buoyant plume front

USGS Publications Warehouse

Gelfenbaum, G.; Stumpf, R.P.

1993-01-01

Observations of the Mobile Bay, Alabama, plume during a flood event in April 1991 reveal significant differences in the current field on either side of a front associated with the buoyant plume. During a strong southeasterly wind, turbid, low salinity water from Mobile Bay was pushed through an opening in the west side of the ebb-tidal delta and moved parallel to the coast. A stable front developed between the low salinity water of the buoyant plume (11‰) and the high salinity coastal water (>23‰) that was being forced landward by the prevailing winds. Despite the shallow water depth of 6 m, measurements of currents, temperature, and salinity show large shears and density gradients in both the vertical and the horizontal directions. At a station outside of the buoyant plume, currents at 0.5 m and 1.5 m below the surface were in the same direction as the wind. Inside the plume, however, currents at 0.5 m below the surface were parallel to the coast, 45°, off the direction of the wind and the magnitude was 45% larger than the magnitude of the surface currents outside the plume. Beneath the level of the plume, the currents were identical to the wind-driven currents in the ambient water south of the front. Our observations suggest that the wind-driven surface currents of the ambient water converged with the buoyant plume at the front and were subducted beneath the plume. The motion of the ambient coastal surface water was in the direction of the local wind stress, however, the motion of the plume had no northerly component of motion. The plume also did not show any flow toward the front, suggesting a balance between the northerly component of wind stress and the southerly component of buoyant spreading. In addition, the motion of the plume did not appear to affect the motion of the underlying ambient water, suggesting a lack of mixing between the two waters.

Setting action levels for drinking water: are we protecting our health or our economy (or our backs!)?

PubMed

Reimann, Clemens; Banks, David

2004-10-01

Clean and healthy drinking water is important for life. Drinking water can be drawn from streams, lakes and rivers, directly collected (and stored) from rain, acquired by desalination of ocean water and melting of ice or it can be extracted from groundwater resources. Groundwater may reach the earth's surface in the form of springs or can be extracted via dug or drilled wells; it also contributes significantly to river baseflow. Different water quality issues have to be faced when utilising these different water resources. Some of these are at present largely neglected in water quality regulations. This paper focuses on the inorganic chemical quality of natural groundwater. Possible health effects, the problems of setting meaningful action levels or maximum admissible concentrations (MAC-values) for drinking water, and potential shortcomings in current legislation are discussed. An approach to setting action levels based on transparency, toxicological risk assessment, completeness, and identifiable responsibility is suggested.

Assessing water quality of the Chesapeake Bay by the impact of sea level rise and warming

NASA Astrophysics Data System (ADS)

Wang, P.; Linker, L.; Wang, H.; Bhatt, G.; Yactayo, G.; Hinson, K.; Tian, R.

2017-08-01

The influence of sea level rise and warming on circulation and water quality of the Chesapeake Bay under projected climate conditions in 2050 were estimated by computer simulation. Four estuarine circulation scenarios in the estuary were run using the same watershed load in 1991-2000 period. They are, 1) the Base Scenario, which represents the current climate condition, 2) a Sea Level Rise Scenario, 3) a Warming Scenario, and 4) a combined Sea Level Rise and Warming Scenario. With a 1.6-1.9°C increase in monthly air temperatures in the Warming Scenario, water temperature in the Bay is estimated to increase by 0.8-1°C. Summer average anoxic volume is estimated to increase 1.4 percent compared to the Base Scenario, because of an increase in algal blooms in the spring and summer, promotion of oxygen consumptive processes, and an increase of stratification. However, a 0.5-meter Sea Level Rise Scenario results in a 12 percent reduction of anoxic volume. This is mainly due to increased estuarine circulation that promotes oxygen-rich sea water intrusion in lower layers. The combined Sea Level Rise and Warming Scenario results in a 10.8 percent reduction of anoxic volume. Global warming increases precipitation and consequently increases nutrient loads from the watershed by approximately 5-7 percent. A scenario that used a 10 percent increase in watershed loads and current estuarine circulation patterns yielded a 19 percent increase in summer anoxic volume, while a scenario that used a 10 percent increase in watershed loads and modified estuarine circulation patterns by the aforementioned sea level rise and warming yielded a 6 percent increase in summer anoxic volume. Impacts on phytoplankton, sediments, and water clarity were also analysed.

Drinking Water Management and Governance in Canada: An Innovative Plan-Do-Check-Act (PDCA) Framework for a Safe Drinking Water Supply

NASA Astrophysics Data System (ADS)

Bereskie, Ty; Rodriguez, Manuel J.; Sadiq, Rehan

2017-08-01

Drinking water management in Canada is complex, with a decentralized, three-tiered governance structure responsible for safe drinking water throughout the country. The current approach has been described as fragmented, leading to governance gaps, duplication of efforts, and an absence of accountability and enforcement. Although there have been no major waterborne disease outbreaks in Canada since 2001, a lack of performance improvement, especially in small drinking water systems, is evident. The World Health Organization water safety plan approach for drinking water management represents an alternative preventative management framework to the current conventional, reactive drinking water management strategies. This approach has seen successful implementation throughout the world and has the potential to address many of the issues with drinking water management in Canada. This paper presents a review and strengths-weaknesses-opportunities-threats analysis of drinking water management and governance in Canada at the federal, provincial/territorial, and municipal levels. Based on this analysis, a modified water safety plan (defined as the plan-do-check-act (PDCA)-WSP framework) is proposed, established from water safety plan recommendations and the principles of PDCA for continuous performance improvement. This proposed framework is designed to strengthen current drinking water management in Canada and is designed to fit within and incorporate the existing governance structure.

Drinking Water Management and Governance in Canada: An Innovative Plan-Do-Check-Act (PDCA) Framework for a Safe Drinking Water Supply.

PubMed

Bereskie, Ty; Rodriguez, Manuel J; Sadiq, Rehan

2017-08-01

Drinking water management in Canada is complex, with a decentralized, three-tiered governance structure responsible for safe drinking water throughout the country. The current approach has been described as fragmented, leading to governance gaps, duplication of efforts, and an absence of accountability and enforcement. Although there have been no major waterborne disease outbreaks in Canada since 2001, a lack of performance improvement, especially in small drinking water systems, is evident. The World Health Organization water safety plan approach for drinking water management represents an alternative preventative management framework to the current conventional, reactive drinking water management strategies. This approach has seen successful implementation throughout the world and has the potential to address many of the issues with drinking water management in Canada. This paper presents a review and strengths-weaknesses-opportunities-threats analysis of drinking water management and governance in Canada at the federal, provincial/territorial, and municipal levels. Based on this analysis, a modified water safety plan (defined as the plan-do-check-act (PDCA)-WSP framework) is proposed, established from water safety plan recommendations and the principles of PDCA for continuous performance improvement. This proposed framework is designed to strengthen current drinking water management in Canada and is designed to fit within and incorporate the existing governance structure.

Using Groundwater Modeling to Evaluate Impacts of Sea Level Rise on A Coastal Riverine Ecosystem: A Case Study of Saint Jones River Water Shed

NASA Astrophysics Data System (ADS)

He, C.; McKenna, T. E.

2016-12-01

A 3-D, transient, variable-density groundwater flow model (SEAWAT) is used to simulate the groundwater response to predicted sea level rise in the Saint Jones River watershed adjacent to the Delaware Estuary. Sea level rise directly leads to substantial changes in the depth of water table, and these changes can extend far inland due to the long tidal rivers in this area. This research studied the impacts of three different sea level rise scenarios (0.5m, 1.0m and 1.5m) on two concerned aspects in the area: failure of septic tank system and loss of agriculture land. The model results indicate that 1) 10% 13% of current existing septic tank will fail as the water table rise to less than 1.5meters from land surface, and 2) approximate 271 to 927 acres of agriculture land, which covers about 4% 13% of total current agriculture land in the study area, will be lost due to water table rise above the effective rooting depth. To count in the uncertainty of climate change in the future, Monte Carlo simulation was applied and a linear transformation model was created and verified to facilitate the tremendous computation.

South Atlantic circulation in a world ocean model

NASA Astrophysics Data System (ADS)

England, Matthew H.; Garçon, Véronique C.

1994-09-01

The circulation in the South Atlantic Ocean has been simulated within a global ocean general circulation model. Preliminary analysis of the modelled ocean circulation in the region indicates a rather close agreement of the simulated upper ocean flows with conventional notions of the large-scale geostrophic currents in the region. The modelled South Atlantic Ocean witnesses the return flow and export of North Atlantic Deep Water (NADW) at its northern boundary, the inflow of a rather barotropic Antarctic Circumpolar Current (ACC) through the Drake Passage, and the inflow of warm saline Agulhas water around the Cape of Good Hope. The Agulhas leakage amounts to 8.7 Sv, within recent estimates of the mass transport shed westward at the Agulhas retroflection. Topographic steering of the ACC dominates the structure of flow in the circumpolar ocean. The Benguela Current is seen to be fed by a mixture of saline Indian Ocean water (originating from the Agulhas Current) and fresher Subantarctic surface water (originating in the ACC). The Benguela Current is seen to modify its flow and fate with depth; near the surface it flows north-westwards bifurcating most of its transport northward into the North Atlantic Ocean (for ultimate replacement of North Atlantic surface waters lost to the NADW conveyor). Deeper in the water column, more of the Benguela Current is destined to return with the Brazil Current, though northward flows are still generated where the Benguela Current extension encounters the coast of South America. At intermediate levels, these northward currents trace the flow of Antarctic Intermediate Water (AAIW) equatorward, though even more AAIW is seen to recirculate poleward in the subtropical gyre. In spite of the model's rather coarse resolution, some subtle features of the Brazil-Malvinas Confluence are simulated rather well, including the latitude at which the two currents meet. Conceptual diagrams of the recirculation and interocean exchange of thermocline, intermediate and deep waters are constructed from an analysis of flows bound between isothermal and isobaric surfaces. This analysis shows how the return path of NADW is partitioned between a cold water route through the Drake Passage (6.5 Sv), a warm water route involving the Agulhas Current sheeding thermocline water westward (2.5 Sv), and a recirculation of intermediate water originating in the Indian Ocean (1.6 Sv).

Ichthyoplankton gut analysis with relevance to prey availability in the waters of Lamon Bay, northeastern Luzon, Philippines

NASA Astrophysics Data System (ADS)

Bollozos, I.; Yniguez, A. T.; Palermo, J. H.; Cabrera, O. C.; Villanoy, C. L.

2013-12-01

The waters in the eastern part of Luzon are highly influenced by the western boundary current system of the western Pacific brought about by the bifurcation of the North Equatorial Current into the Kuroshio and Mindanao Current. Eddies are formed with varying intensities as an effect of the ENSO cycle. Three spatial zones were identified according to prominent current movements and circulations observed during the summer 2011 and 2012 oceanographic cruises. These events also affect the productivity in the surrounding waters. Plankton samples were collected to determine the relative abundances of major groups representing three trophic levels. The abundance and composition of phyto- and zooplankton major groups slightly varied among the zones. Gut analysis of fish larvae was then conducted to determine potential prey preference and linked to the phyto- and zooplankton densities.

A brief overview on radon measurements in drinking water.

PubMed

Jobbágy, Viktor; Altzitzoglou, Timotheos; Malo, Petya; Tanner, Vesa; Hult, Mikael

2017-07-01

The aim of this paper is to present information about currently used standard and routine methods for radon analysis in drinking waters. An overview is given about the current situation and the performance of different measurement methods based on literature data. The following parameters are compared and discussed: initial sample volume and sample preparation, detection systems, minimum detectable activity, counting efficiency, interferences, measurement uncertainty, sample capacity and overall turnaround time. Moreover, the parametric levels for radon in drinking water from the different legislations and directives/guidelines on radon are presented. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The need for a reassessment of the safe upper limit of selenium in drinking water.

PubMed

Vinceti, Marco; Crespi, Catherine M; Bonvicini, Francesca; Malagoli, Carlotta; Ferrante, Margherita; Marmiroli, Sandra; Stranges, Saverio

2013-01-15

Results of recent epidemiologic studies suggest the need to reassess the safe upper limit in drinking water of selenium, a metalloid with both toxicological and nutritional properties. Observational and experimental human studies on health effects of organic selenium compounds consumed through diet or supplements, and of inorganic selenium consumed through drinking water, have shown that human toxicity may occur at much lower levels than previously surmised. Evidence indicates that the chemical form of selenium strongly influences its toxicity, and that its biological activity may differ in different species, emphasizing the importance of the few human studies on health effects of the specific selenium compounds found in drinking water. Epidemiologic studies that investigated the effects of selenate, an inorganic selenium species commonly found in drinking water, together with evidence of toxicity of inorganic selenium at low levels in from in vitro and animal studies, indicate that health risks may occur at exposures below the current European Union and World Health Organization upper limit and guideline of 10 and 40 μg/l, respectively, and suggest reduction to 1 μg/l in order to adequately protect human health. Although few drinking waters are currently known to have selenium concentrations exceeding this level, the public health importance of this issue should not be overlooked, and further epidemiologic research is critically needed in this area. Copyright © 2012 Elsevier B.V. All rights reserved.

Demonstration and Evaluation of an Innovative Water Main Rehabilitation Technology: Spray-on Polymeric Lining

EPA Science Inventory

Many utilities are seeking innovative rehabilitation technologies to extend the life and fix larger portions of their water distribution systems with current funding levels. The information on the capabilities and applicability of new technologies is not always readily available...

Everglades Depth Estimation Network (EDEN) Applications: Tools to View, Extract, Plot, and Manipulate EDEN Data

USGS Publications Warehouse

Telis, Pamela A.; Henkel, Heather

2009-01-01

The Everglades Depth Estimation Network (EDEN) is an integrated system of real-time water-level monitoring, ground-elevation data, and water-surface elevation modeling to provide scientists and water managers with current on-line water-depth information for the entire freshwater part of the greater Everglades. To assist users in applying the EDEN data to their particular needs, a series of five EDEN tools, or applications (EDENapps), were developed. Using EDEN's tools, scientists can view the EDEN datasets of daily water-level and ground elevations, compute and view daily water depth and hydroperiod surfaces, extract data for user-specified locations, plot transects of water level, and animate water-level transects over time. Also, users can retrieve data from the EDEN datasets for analysis and display in other analysis software programs. As scientists and managers attempt to restore the natural volume, timing, and distribution of sheetflow in the wetlands, such information is invaluable. Information analyzed and presented with these tools is used to advise policy makers, planners, and decision makers of the potential effects of water management and restoration scenarios on the natural resources of the Everglades.

Fluoride content of still bottled water in Australia.

PubMed

Cochrane, N J; Saranathan, S; Morgan, M V; Dashper, S G

2006-09-01

Recently there has been a considerable increase in the consumption of bottled water in Australia. Overseas studies have found the fluoride levels in many bottled waters are well below levels considered optimal for preventing dental caries. This raises the concern that if bottled water is regularly consumed an effective means of preventing dental caries is unavailable. The aim of this study was to determine the fluoride concentration in 10 popular brands of still bottled water currently sold in Australia. The fluoride content of water samples were determined using an ion analyser and compared to a fluoride standard. The fluoride concentration of all bottled waters was less than 0.08 ppm. Only three of the 10 brands indicated the fluoride content on their labels. Melbourne reticulated water was found to be fluoridated at 1.02 ppm. All bottled waters tested contained negligible fluoride which justifies the concern that regular consumption of bottled water may reduce the benefits gained from water fluoridation. It is recommended that all bottled water companies should consider stating their fluoride content on their labels. This will inform consumers and dental care providers of the levels of fluoride in bottled water and allow an informed decision regarding consumption of fluoridated versus non-fluoridated drinking water.

Effects of wave-induced forcing on a circulation model of the North Sea

NASA Astrophysics Data System (ADS)

Staneva, Joanna; Alari, Victor; Breivik, Øyvind; Bidlot, Jean-Raymond; Mogensen, Kristian

2017-04-01

The effect of wind waves on water level and currents during two storms in the North Sea is investigated using a high-resolution NEMO model forced with fluxes and fields from a high-resolution wave model. The additional terms accounting for wave-current interaction that are considered in this study are the Stokes-Coriolis force and the sea-state dependent energy and momentum fluxes. The individual and collective role of these processes is quantified and the results are compared with a control run without wave effects as well as against current and water level measurements from coastal stations. We find a better agreement with observations when the circulation model is forced by sea-state dependent fluxes, especially in extreme events. The two extreme events, the storm Christian (25-27 October 2013), and about a month later, the storm Xaver (5-7 December 2013), induce different wave and surge conditions over the North Sea. Including the wave effects in the circulation model for the storm Xaver raises the modelled surge by more than 40 cm compared with the control run in the German Bight area. For the storm Christian, a difference of 20-30 cm in the surge level between the wave-forced and the stand-alone ocean model is found over the whole southern part of the North Sea. Moreover, the modelled vertical velocity profile fits the observations very well when the wave forcing is accounted for. The contribution of wave-induced forcing has been quantified indicating that this represents an important mechanism for improving water level and current predictions.

Effects of wave-induced forcing on a circulation model of the North Sea

NASA Astrophysics Data System (ADS)

Staneva, Joanna; Alari, Victor; Breivik, Øyvind; Bidlot, Jean-Raymond; Mogensen, Kristian

2017-01-01

The effect of wind waves on water level and currents during two storms in the North Sea is investigated using a high-resolution Nucleus for European Modelling of the Ocean (NEMO) model forced with fluxes and fields from a high-resolution wave model. The additional terms accounting for wave-current interaction that are considered in this study are the Stokes-Coriolis force, the sea-state-dependent energy and momentum fluxes. The individual and collective role of these processes is quantified and the results are compared with a control run without wave effects as well as against current and water-level measurements from coastal stations. We find a better agreement with observations when the circulation model is forced by sea-state-dependent fluxes, especially in extreme events. The two extreme events, the storm Christian (25-27 October 2013), and about a month later, the storm Xaver (5-7 December 2013), induce different wave and surge conditions over the North Sea. Including the wave effects in the circulation model for the storm Xaver raises the modelled surge by more than 40 cm compared with the control run in the German Bight area. For the storm Christian, a difference of 20-30 cm in the surge level between the wave-forced and the stand-alone ocean model is found over the whole southern part of the North Sea. Moreover, the modelled vertical velocity profile fits the observations very well when the wave forcing is accounted for. The contribution of wave-induced forcing has been quantified indicating that this represents an important mechanism for improving water-level and current predictions.

RECENT DEVELOPMENTS IN HYDROLOGIC INSTRUMENTATION.

USGS Publications Warehouse

Latkovich, Vito J.

1985-01-01

The availability of space-age materials and implementation of state-of-the-art electronics is making possible the recent developments of hydrologic instrumentation. Material developments include: Synthetic-fiber sounding and tag lines; fiberglass wading rod; polymer (plastic) sheaves, pulleys and sampler components; and polymer (plastic) bucket wheels for current meters. These materials are very cost effective and efficient. Electromechanical and electronic developments and applications include: adaptable data acquisition system; downhole sampler for hazardous substances; current-meter digitizer; hydraulic power/drive system for discharge measurements and water-quality sampling; non-contact water-level sensors; minimum data recorder; acoustic velocity meters, and automated current meter discharge-measurement system.

ESTIMATION OF GIARDIA CT VALUES AT HIGH PH FOR THE SURFACE WATER TREATMENT RULE

EPA Science Inventory

The U.S. Environmental Protection Agency currently recommends Ct (disinfectant concentration multiplied by the exposure time) values to achieve required levels of inactivation of Giardia lamblia cysts by different disinfectants including free chlorine. Current guidance covers ina...

Water Quality Investigations at Lake Merritt in Oakland, California

NASA Astrophysics Data System (ADS)

Carter, G.; Casino, C.; Johnson, K.; Huang, J.; Le, A.; Truisi, V. M.; Turner, D.; Yanez, F.; Yu, J. F.; Unigarro, M.; Vue, G.; Garduno, L.; Cuff, K.

2005-12-01

Lake Merritt is a saltwater tidal lagoon that forms a portion of a wildlife refuge in downtown Oakland, California. The general area was designated as the nation's first wildlife refuge in 1869, and is currently the home to over 90 species of migrating waterfowl, as well as a variety of aquatic wildlife. Situated within an area composed of compacted marine sediment located near the center of Oakland, Lake Merritt also serves as a major local catchment basin, receiving significant urban runoff from a 4,650 acre local watershed through 60 storm drains and four culverted creeks. Due to factors related to its geographical location, Lake Merritt has suffered from poor water quality at various times throughout its history. In fact, in May of 1999 the US Environmental Protection Agency designated Lake Merritt as a body of water whose beneficial uses are impaired, mainly due to high levels of trash and low levels of dissolved oxygen. As a contribution to continuing efforts to monitor and assess water quality of the Lake, we began a water quality investigation during the Summer of 2005, which included the measurement of dissolved oxygen concentrations of samples collected near its surface at over 85 different locations. These measurements were made using a sensor attached to a PASCO data- logger. The sensor measures the electric current produced by a chemical reaction in its probe, which is composed of a platinum cathode and a silver anode surrounded by an electrolyte solution. Results of these measurements were statistically analyzed, mapped, and then used in assessing the quality of Lake Merritt's water, particularly in relation to supporting aquatic biota. Preliminary analysis of results obtained so far indicates that the highest quality waters in Lake Merritt occur in areas that are closest to a source of San Francisco Bay water, as well as those areas nearby where water circulation is robust. Significantly high levels of dissolved oxygen were measured in an area that has the greatest number and diversity of organisms as indicated through visual observation, which is located where marine waters flow directly into the Lake. In addition, high levels of dissolved oxygen were measured at two sites along an approximately 500 meters stretch of the Lake's eastern shoreline, where swift moving currents were observed. Dissolved oxygen levels were lowest in areas where storm drain runoff waters flow into the Lake, as well as those that include trash-filled, stagnant sections. Overall, our work has generated information that may be used to better understand important factors that affect Lake Merritt's water quality. Such studies should be continued in the future and used to help maintain a healthy ecosystem in and around Lake Merritt.

Sedimentary noise and sea levels linked to land-ocean water exchange and obliquity forcing.

PubMed

Li, Mingsong; Hinnov, Linda A; Huang, Chunju; Ogg, James G

2018-03-08

In ancient hothouses lacking ice sheets, the origins of large, million-year (myr)-scale sea-level oscillations remain a mystery, challenging current models of sea-level change. To address this mystery, we develop a sedimentary noise model for sea-level changes that simultaneously estimates geologic time and sea level from astronomically forced marginal marine stratigraphy. The noise model involves two complementary approaches: dynamic noise after orbital tuning (DYNOT) and lag-1 autocorrelation coefficient (ρ 1 ). Noise modeling of Lower Triassic marine slope stratigraphy in South China reveal evidence for global sea-level variations in the Early Triassic hothouse that are anti-phased with continental water storage variations in the Germanic Basin. This supports the hypothesis that long-period (1-2 myr) astronomically forced water mass exchange between land and ocean reservoirs is a missing link for reconciling geological records and models for sea-level change during non-glacial periods.

The Water Footprint as an indicator of environmental sustainability in water use at the river basin level.

PubMed

Pellicer-Martínez, Francisco; Martínez-Paz, José Miguel

2016-11-15

One of the main challenges in water management is to determine how the current water use can condition its availability to future generations and hence its sustainability. This study proposes the use of the Water Footprint (WF) indicator to assess the environmental sustainability in water resources management at the river basin level. The current study presents the methodology developed and applies it to a case study. The WF is a relatively new indicator that measures the total volume of freshwater that is used as a production factor. Its application is ever growing in the evaluation of water use in production processes. The calculation of the WF involves water resources (blue), precipitation stored in the soil (green) and pollution (grey). It provides a comprehensive assessment of the environmental sustainability of water use in a river basin. The methodology is based upon the simulation of the anthropised water cycle, which is conducted by combining a hydrological model and a decision support system. The methodology allows the assessment of the environmental sustainability of water management at different levels, and/or ex-ante analysis of how the decisions made in water planning process affect sustainability. The sustainability study was carried out in the Segura River Basin (SRB) in South-eastern Spain. The SRB is among the most complex basins in Europe, given its special peculiarities: competition for the use, overexploitation of aquifers, pollution, alternative sources, among others. The results indicate that blue water use is not sustainable due to the generalised overexploitation of aquifers. They also reveal that surface water pollution, which is not sustainable, is mainly caused by phosphate concentrations. The assessment of future scenarios reveals that these problems will worsen if no additional measures are implemented, and therefore the water management in the SRB is environmentally unsustainable in both the short- and medium-term. Copyright © 2016 Elsevier B.V. All rights reserved.

Potential effects of sea-level rise on the depth to saturated sediments of the Sagamore and Monomoy flow lenses on Cape Cod, Massachusetts

USGS Publications Warehouse

Walter, Donald A.; McCobb, Timothy D.; Masterson, John P.; Fienen, Michael N.

2016-05-25

In 2014, the U.S. Geological Survey, in cooperation with the Association to Preserve Cape Cod, the Cape Cod Commission, and the Massachusetts Environmental Trust, began an evaluation of the potential effects of sea-level rise on water table altitudes and depths to water on central and western Cape Cod, Massachusetts. Increases in atmospheric and oceanic temperatures arising, in part, from the release of greenhouse gases likely will result in higher sea levels globally. Increasing water table altitudes in shallow, unconfined coastal aquifer systems could adversely affect infrastructure—roads, utilities, basements, and septic systems—particularly in low-lying urbanized areas. The Sagamore and Monomoy flow lenses on Cape Cod are the largest and most populous of the six flow lenses that comprise the region’s aquifer system, the Cape Cod glacial aquifer. The potential effects of sea-level rise on water table altitude and depths to water were evaluated by use of numerical models of the region. The Sagamore and Monomoy flow lenses have a number of large surface water drainages that receive a substantial amount of groundwater discharge, 47 and 29 percent of the total, respectively. The median increase in the simulated water table altitude following a 6-foot sea-level rise across both flow lenses was 2.11 feet, or 35 percent when expressed as a percentage of the total sea-level rise. The response is nearly the same as the sea-level rise (6 feet) in some coastal areas and less than 0.1 foot near some large inland streams. Median water table responses differ substantially between the Sagamore and Monomoy flow lenses—at 29 and 49 percent, respectively—because larger surface water discharge on the Sagamore flow lens results in increased dampening of the water table response than in the Monomoy flow lens. Surface waters dampen water table altitude increases because streams are fixed-altitude boundaries that cause hydraulic gradients and streamflow to increase as sea-level rises, partially fixing the local water table altitude.The region has a generally thick vadose zone with a mean of about 38 feet; areas with depths to water of 5 feet or less, as estimated from light detection and ranging (lidar) data from 2011 and simulated water table altitudes, currently [2011] occur over about 24.9 square miles, or about 8.4 percent of the total land area of the Sagamore and Monomoy flow lenses, generally in low-lying coastal areas and inland near ponds and streams. Excluding potentially submerged areas, an additional 4.5, 9.8, and 15.9 square miles would have shallow depths to water (5 feet or less) for projected sea-level rises of 2, 4, and 6 feet above levels in 2011. The additional areas with shallow depths to water generally occur in the same areas as the areas with current [2011] depths to water of 5 feet or less: low-lying coastal areas and near inland surface water features. Additional areas with shallow depths to water for the largest sea-level rise prediction (6 feet) account for about 5.7 percent of the total land area, excluding areas likely to be inundated by seawater. The numerous surface water drainages will dampen the response of the water table to sea-level rise. This dampening, combined with the region’s thick vadose zone, likely will mitigate the potential for groundwater inundation in most areas. The potential does exist for groundwater inundation in some areas, but the effects of sea-level rise on depths to water and infrastructure likely will not be substantial on a regional level.

The unintended energy impacts of increased nitrate contamination from biofuels production.

PubMed

Twomey, Kelly M; Stillwell, Ashlynn S; Webber, Michael E

2010-01-01

Increases in corn cultivation for biofuels production, due to the Energy Independence and Security Act of 2007, are likely to lead to increases in nitrate concentrations in both surface and groundwater resources in the United States. These increases might trigger the requirement for additional energy consumption for water treatment to remove the nitrates. While these increasing concentrations of nitrate might pose a human health concern, most water resources were found to be within current maximum contaminant level (MCL) limits of 10 mg L(-1) NO(3)-N. When water resources exceed this MCL, energy-intensive drinking water treatment is required to reduce nitrate levels below 10 mg L(-1). Based on prior estimates of water supplies currently exceeding the nitrate MCL, we calculate that advanced drinking water treatment might require an additional 2360 million kWh annually (for nitrate affected areas only)--a 2100% increase in energy requirements for water treatment in those same areas--to mitigate nitrate contamination and meet the MCL requirement. We predict that projected increases in nitrate contamination in water may impact the energy consumed in the water treatment sector, because of the convergence of several related trends: (1) increasing cornstarch-based ethanol production, (2) increasing nutrient loading in surface water and groundwater resources as a consequence of increased corn-based ethanol production, (3) additional drinking water sources that exceed the MCL for nitrate, and (4) potentially more stringent drinking water standards for nitrate.

METHODS FOR THE ANALYSIS OF PRIORITY DBPS IN RO-CONCENTRATED DRINKING WATER

EPA Science Inventory

The ability to understand mechanisms of formation and occurrence of disinfection by-products (DBPs) resulting from treatment of natural waters has been limited to those formed at µg/L levels. Toxicological evaluations suggest that many of the DBPs missing from current regula...

NOAA PORTS PROGRAM

Science.gov Websites

greater danger near shore or any shallow waters? NOAA PORTS PROGRAM The Physical Oceanographic Real-Time navigation by providing ship masters and pilots with accurate real-time information required to avoid data acquisition and dissemination systems that provide real-time water levels, currents, and other

Ground-water resources of the lower Rio Grande Valley area, Texas

USGS Publications Warehouse

Baker, R.C.; Dale, O.C.

1964-01-01

Further studies should be made in the area to correct important deficiencies in available information. A continuing program is recommended because information such as fluctuations in water levels and the amount and distribution of pumping can be obtained only on a current basis.

Seasonal presence of cetaceans and ambient noise levels in polar waters of the North Atlantic.

PubMed

Klinck, Holger; Nieukirk, Sharon L; Mellinger, David K; Klinck, Karolin; Matsumoto, Haruyoshi; Dziak, Robert P

2012-09-01

In 2009 two calibrated acoustic recorders were deployed in polar waters of the North Atlantic to study the seasonal occurrence of blue, fin, and sperm whales and to assess current ambient noise levels. Sounds from these cetaceans were recorded at both locations in most months of the year. During the summer months, seismic airguns associated with oil and gas exploration were audible for weeks at a time and dominated low frequency noise levels. Noise levels might further increase in the future as the receding sea ice enables extended human use of the area.

The Caspian Sea water dynamics based on satellite imagery and altimetry

NASA Astrophysics Data System (ADS)

Kostianoy, Andrey G.; Lebedev, Sergey

The Caspian Sea water dynamics is poorly known due to a lack of special hydrographic measurements. The known schemes of general circulation of the sea proposed by N.M. Knipovich in 1914-1915 and 1921, A.I. Mikhalevskiy (1931), G.N. Zaitsev (1935) and V.N. Zenin (1942) represent the basin-scale cyclonic gyres in the Middle and Southern Caspian, and no clear scheme for the shallow Northern Caspian. Later numerical models could move forward from these simple schemes of circulation to the more detailed seasonal or climatic schemes of currents, but different approaches and models give different results which significantly differ from each other (Trukhchev et al., 1995; Ibrayev et al., 2003, 2010; Popov, 2004, 2009; Knysh et al., 2008). Satellite monitoring of the Caspian Sea, we perform since 2000, is a useful tool for investigation of water dynamics in the Caspian Sea. To determine mesoscale water structure and dynamics, we used different kind of physical (SST and ice), chemical (suspended matter and water turbidity) and biological (chlorophyll concentration and algal bloom) tracers on satellite imagery. Satellite altimetry (sea level anomalies in combination with the mean dynamic level derived from numerical modeling) provides fields of currents in the whole Caspian Sea on a regular basis (every 10 days). Seasonal fields of currents derived from satellite altimetry also differ from those obtained in numerical models. Finally, we show the results of the first drifter experiment performed in the Caspian Sea in 2006-2008 in the framework of the MACE Project. Special attention is paid to the seasonal upwelling along the eastern coast of the sea, coastal currents, and a giant intrusion of warm water from the Southern to the Middle Caspian Sea.

The World Health Organization's water safety plan is much more than just an integrated drinking water quality management plan.

PubMed

Viljoen, F C

2010-01-01

South Africa is a country of contrasts with far ranging variations in climate, precipitation rates, cultures, demographics, housing levels, education, wealth and skills levels. These differences have an impact on water services delivery as do expectations, affordability and available resources. Although South Africa has made much progress in supplying drinking water, the same cannot be said regarding water quality throughout the country. A concerted effort is currently underway to correct this situation and as part of this drive, water safety plans (WSP) are promoted. Rand Water, the largest water services provider in South Africa, used the World Health Organization (WHO) WSP framework as a guide for the development of its own WSP which was implemented in 2003. Through the process of implementation, Rand Water found the WHO WSP to be much more than just another integrated quality system.

Ships' Ballast Water Treatment by Chlorination Can Generate Toxic Trihalomethanes.

PubMed

Hernandez, Marco R; Ismail, Nargis; Drouillard, Ken G; MacIsaac, Hugh J

2017-08-01

The International Maritime Organization (IMO) will enforce a new abundance-based performance standard for ballast water in September, 2017. Strong oxidants, like chlorine, have been proposed as a method for achieving this standard. However chlorine treatment of ballast water can produce hazardous trihalomethanes. We assessed maximum trihalomethane production from one chlorine dose for three types of ballast water (fresh, brackish and marine) and three levels of total organic carbon (TOC) concentration (natural, filtered, enhanced). While the current standard test considers a 5 day voyage, there is a high possibility of shorter trips and sudden change of plans that will release treated waters in the environment. Water source and TOC significantly affected trihalomethane production, with the highest amounts generated in brackish waters and enhanced TOC concentration. The concentration of brominated trihalomethanes increased from background levels and was highest in brackish water, followed by marine and fresh water.

Arsenic in drinking water and adverse birth outcomes in Ohio.

PubMed

Almberg, Kirsten S; Turyk, Mary E; Jones, Rachael M; Rankin, Kristin; Freels, Sally; Graber, Judith M; Stayner, Leslie T

2017-08-01

Arsenic in drinking water has been associated with adverse reproductive outcomes in areas with high levels of naturally occurring arsenic. Less is known about the reproductive effects of arsenic at lower levels. This research examined the association between low-level arsenic in drinking water and small for gestational age (SGA), term low birth weight (term LBW), very low birth weight (VLBW), preterm birth (PTB), and very preterm birth (VPTB) in the state of Ohio. Exposure was defined as the mean annual arsenic concentration in drinking water in each county in Ohio from 2006 to 2008 using Safe Drinking Water Information System data. Birth outcomes were ascertained from the birth certificate records of 428,804 births in Ohio from the same time period. Multivariable generalized estimating equation logistic regression models were used to assess the relationship between arsenic and each birth outcome separately. Sensitivity analyses were performed to examine the roles of private well use and prenatal care utilization in these associations. Arsenic in drinking water was associated with increased odds of VLBW (AOR 1.14 per µg/L increase; 95% CI 1.04, 1.24) and PTB (AOR 1.10; 95% CI 1.06, 1.15) among singleton births in counties where <10% of the population used private wells. No significant association was observed between arsenic and SGA, or VPTB, but a suggestive association was observed between arsenic and term LBW. Arsenic in drinking water was positively associated with VLBW and PTB in a population where nearly all (>99%) of the population was exposed under the current maximum contaminant level of 10µg/L. Current regulatory standards may not be protective against reproductive effects of prenatal exposure to arsenic. Copyright © 2017 Elsevier Inc. All rights reserved.

Determination of ultratrace levels of tributyltin in waters by isotope dilution and gas chromatography coupled to tandem mass spectrometry.

PubMed

Rodríguez-Cea, Andrés; Rodríguez-González, Pablo; Font Cardona, Nuria; Aranda Mares, José Luís; Ballester Nebot, Salomé; García Alonso, J Ignacio

2015-12-18

The current EU legislation lays down the Environmental Quality Standards (EQS) of 45 priority substances in surface water bodies. In particular, the concentration of tributyltin (TBT) must not exceed 0.2ngL(-1) and analytical methodologies with a Limit of Quantification (LOQ) equal or below 0.06ngL(-1) are urged to be developed. This work presents a procedure for the determination of ultratrace levels of TBT in water samples by Isotope Dilution and GC-MS/MS operating in Selected Reaction Monitoring (SRM) mode which meets current EU requirements. The method requires the monitorization of five consecutive transitions (287>175 to 291>179) for the sensitive and selective detection of TBT. The measured isotopic distribution of TBT fragment ions was in agreement with the theoretical values computed by a polynomial expansion algorithm. The combined use of Tandem Mass Spectrometry, a sample volume of 250mL, the preconcentration of 1mL of organic phase to 30μL and an injection volume of 25μL by Programmed Temperature Vaporization provided a LOQ of 0.0426ngL(-1) for TBT (calculated as ten times the standard deviation of nine independent blanks). The recovery for TBT calculated in Milli-Q water at the EQS level was 106.3±4%. A similar procedure was also developed for the quantification of dibutyltin (DBT) and monobutyltin (MBT) in water samples showing satisfactory results. The method was finally implemented in a routine testing laboratory to demonstrate its applicability to real samples obtaining quantitative recoveries for TBT at the EQS level in mineral water, river water and seawater. Copyright © 2015 Elsevier B.V. All rights reserved.

Prototype continuous flow ventricular assist device supported on magnetic bearings.

PubMed

Allaire, P E; Kim, H C; Maslen, E H; Olsen, D B; Bearnson, G B

1996-06-01

This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells.

Optimal water resources management and system benefit for the Marcellus shale-gas reservoir in Pennsylvania and West Virginia

NASA Astrophysics Data System (ADS)

Cheng, Xi; He, Li; Lu, Hongwei; Chen, Yizhong; Ren, Lixia

2016-09-01

A major concern associated with current shale-gas extraction is high consumption of water resources. However, decision-making problems regarding water consumption and shale-gas extraction have not yet been solved through systematic approaches. This study develops a new bilevel optimization problem based on goals at two different levels: minimization of water demands at the lower level and maximization of system benefit at the upper level. The model is used to solve a real-world case across Pennsylvania and West Virginia. Results show that surface water would be the largest contributor to gas production (with over 80.00% from 2015 to 2030) and groundwater occupies for the least proportion (with less than 2.00% from 2015 to 2030) in both districts over the planning span. Comparative analysis between the proposed model and conventional single-level models indicates that the bilevel model could provide coordinated schemes to comprehensively attain the goals from both water resources authorities and energy sectors. Sensitivity analysis shows that the change of water use of per unit gas production (WU) has significant effects upon system benefit, gas production and pollutants (i.e., barium, chloride and bromide) discharge, but not significantly changes water demands.

Developing a cost effective environmental solution for produced water and creating a ''new'' water resource

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

Doran, Glenn; Leong, Lawrence Y.C.

2000-05-01

The project goal is to convert a currently usable by-product of oil production, produced water, into a valuable drinking water resource. The project was located at the Placate Oil Field in Santa Clarita, California, approximately 25 miles north of Los Angeles. The project included a literature review of treatment technologies; preliminary bench-scale studies to refine a planning level cost estimate; and a 10-100 gpm pilot study to develop the conceptual design and cost estimate for a 44,000 bpd treatment facility. A reverse osmosis system was constructed, pilot tested, and the data used to develop a conceptual design and operation ofmore » four operational scenarios, two industrial waters levels and two irrigation/potable water.« less

Annual summary of ground-water conditions in Arizona, spring 1977 to spring 1978

USGS Publications Warehouse

,

1978-01-01

The withdrawal of ground water was about 5.5 million acre-feet in Arizona in 1977. About 4.7 million acre-feet of ground water was used for the irrigation of crops in 1977. The Salt River Valley and the lower Santa Cruz basin are the largest agricultural areas in the State. For 1973-77, ground-water withdrawal in the two areas was about 8.1 and 5.1 million acre-feet, respectively, and, in general, water levels are declining. Other areas in which ground-water withdrawals have caused water-level declines are the Willcox, San Simon, upper Santa Cruz, Avra Valley, Gila Bend, Harquahala Plains, and McMullen Valley areas. Two small-scale maps of Arizona show (1) pumpage of ground water by areas and (2) the status of the ground-water inventory in the State. The main map, scale 1:500 ,000, shows potential well production, depth to water in selected wells in spring 1978, and change in water level in selected wells from 1973 to 1978. The brief text that accompanies the maps summarizes the current ground-water conditions in the State. (Woodard-USGS)

Continued geophysical logging near the GMH Electronics National Priorities List Superfund site near Roxboro, North Carolina

USGS Publications Warehouse

Antolino, Dominick J.; Chapman, Melinda J.

2017-01-06

The U.S. Geological Survey South Atlantic Water Science Center collected borehole geophysical logs and images and continuous water-level data near the GMH Electronics National Priorities List Superfund site near Roxboro, North Carolina, during December 2012 through July 2015. Previous work by the U.S. Geological Survey South Atlantic Water Science Center at the site involved the collection of borehole geophysical log data in 15 wells, in addition to surface geologic mapping and passive diffusion bag sampling. In a continued effort to assist the U.S. Environmental Protection Agency in developing a conceptual groundwater model to assess current contaminant distribution and future migration of contaminants, more than 900 subsurface features (primarily fracture orientations) in 10 open borehole wells were delineated and continuous water-level data information from 14 monitoring wells within close proximity of the initially drilled boreholes was collected to observe any induced water-level fluctuations during drilling operations

Forecasting drought risks for a water supply storage system using bootstrap position analysis

USGS Publications Warehouse

Tasker, Gary; Dunne, Paul

1997-01-01

Forecasting the likelihood of drought conditions is an integral part of managing a water supply storage and delivery system. Position analysis uses a large number of possible flow sequences as inputs to a simulation of a water supply storage and delivery system. For a given set of operating rules and water use requirements, water managers can use such a model to forecast the likelihood of specified outcomes such as reservoir levels falling below a specified level or streamflows falling below statutory passing flows a few months ahead conditioned on the current reservoir levels and streamflows. The large number of possible flow sequences are generated using a stochastic streamflow model with a random resampling of innovations. The advantages of this resampling scheme, called bootstrap position analysis, are that it does not rely on the unverifiable assumption of normality and it allows incorporation of long-range weather forecasts into the analysis.

The Pianosa Contourite Depositional System (Northern Tyrrhenian Sea): drift morphology and Plio-Quaternary stratigraphic evolution

NASA Astrophysics Data System (ADS)

Miramontes Garcia, Elda; Cattaneo, Antonio; Jouet, Gwenael; Thereau, Estelle; Thomas, Yannick; Rovere, Marzia; Cauquil, Eric; Trincardi, Fabio

2016-04-01

The Pianosa Contourite Depositional System (CDS) is located in the Corsica Trough (Northern Tyrrhenian Sea), a confined basin dominated by mass transport and contour currents in the eastern flank and by turbidity currents in the western flank. The morphologic and stratigraphic characterisation of the Pianosa CDS is based on multibeam bathymetry, seismic reflection data (multi-channel high resolution mini GI gun, single-channel sparker and CHIRP), sediment cores and ADCP data. The Pianosa CDS is located at shallow to intermediate water depths (170 to 850 m water depth) and is formed under the influence of the Levantine Intermediate Water (LIW). It is 120 km long, has a maximum width of 10 km and is composed of different types of muddy sediment drifts: plastered drift, separated mounded drift, sigmoid drift and multicrested drift. The reduced tectonic activity in the Corsica Trough since the early Pliocene permits to recover a sedimentary record of the contourite depositional system that is only influenced by climate fluctuations. Contourites started to develop in the Middle-Late Pliocene, but their growth was enhanced since the Middle Pleistocene Transition (0.7-0.9 Ma). Although the general circulation of the LIW, flowing northwards in the Corsica Trough, remained active all along the history of the system, contourite drift formation changed, controlled by sediment influx and bottom current velocity. During periods of sea level fall, fast bottom currents often eroded the drift crest in the middle and upper slope. At that time the proximity of the coast to the shelf edge favoured the formation of bioclastic sand deposits winnowed by bottom currents. Higher sediment accumulation of mud in the drifts occurred during periods of fast bottom currents and high sediment availability (i.e. high activity of turbidity currents), coincident with periods of sea level low-stands. Condensed sections were formed during sea level high-stands, when bottom currents were more sluggish and the turbidite system was disconnected, resulting in a lower sediment influx.

Exploring the temporal effects of seasonal water availability on the snail kite of Florida: Part III

USGS Publications Warehouse

Mooij, Wolf M.; Martin, Julien; Kitchens, Wiley M.; DeAngelis, Donald L.

2007-01-01

The Florida snail kite (Rostrhamus sociabilis) is an endangered raptor that occurs as an isolated population, currently of about 2,000 birds, in the wetlands of southern and central Florida, USA. Its exclusive prey species, the apple snail (Pomacea paludosa) is strongly influenced by seasonal changes in water abundance. Droughts during the snail kite breeding season have a direct negative effect on snail kite survival and reproduction, but droughts are also needed to maintain aquatic vegetation types favorable to snail kite foraging for snails. We used a spatially explicit matrix model to explore the effects of temporal variation in water levels on the viability of the snail kite population under different temporal drought regimes in its wetland breeding habitat. We focused on three aspects of variations in water levels that were likely to affect kites: (1) drought frequency; (2) drought duration; and (3) drought timing within the year. We modeled a 31-year historical scenario using four different scenarios in which the average water level was maintained constant, but the amplitude of water level fluctuations was modified. Our results reveal the complexity of the effects of temporal variation in water levels on snail kite population dynamics. Management implications of these results are discussed. In particular, management decisions should not be based on annual mean water levels alone, but must consider the intra-annual variability.

Electrochemical disinfection using boron-doped diamond electrode--the synergetic effects of in situ ozone and free chlorine generation.

PubMed

Rajab, Mohamad; Heim, Carolin; Letzel, Thomas; Drewes, Jörg E; Helmreich, Brigitte

2015-02-01

This work investigated the capability of using a boron-doped diamond (BDD) electrode for bacterial disinfection in different water matrices containing varying amounts of chloride. The feed water containing Pseudomonas aeruginosa was electrochemically treated while applying different electrode conditions. Depending on the applied current density and the exposure time, inactivation between 4- and 8-log of the targeted microorganisms could be achieved. The disinfection efficiency was driven by the generation of free chlorine as a function of chloride concentration in the water. A synergetic effect of generating both free chlorine and ozone in situ during the disinfection process resulted in an effective bactericidal impact. The formation of the undesired by-products chlorate and perchlorate depended on the water matrix, the applied current density and the desired target disinfection level. In case of synthetic water with a low chloride concentration (20 mg L(-1)) and an applied current density of 167 mA cm(-2), a 6-log inactivation of Pseudomonas aeruginosa could be achieved after 5 min of exposure. The overall energy consumption ranged between 0.3 and 0.6 kW h m(-3) depending on the applied current density and water chemistry. Electrochemical water disinfection represents a suitable and efficient process for producing pathogen-free water without the use of any chemicals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Observations of the southern East Madagascar Current and undercurrent and countercurrent system

NASA Astrophysics Data System (ADS)

Nauw, J. J.; van Aken, H. M.; Webb, A.; Lutjeharms, J. R. E.; de Ruijter, W. P. M.

2008-08-01

In April 2001 four hydrographic sections perpendicular to the southern East Madagascar Current were surveyed as part of the Agulhas Current Sources Experiment. Observations with a vessel mounted and a lowered ADCP produced information on the current field while temperature, salinity, oxygen and nutrient data obtained with a CTD-Rosette system, gave information on the water mass structure of the currents southeast of Madagascar. The peak velocity in the pole-ward East Madagascar Current through these four sections had a typical magnitude of ˜110 cm/s, while the width of this current was of the order of 120 km. The mean pole-ward volume transport rate of this current during the survey above the 5°C isotherm was estimated to be 37 ± 10 Sv. On all four sections an undercurrent was observed at intermediate depths below the East Madagascar Current. Its equator-ward transport rate amounted to 2.8 ± 1.4 Sv. Offshore of the East Madagascar Current the shallow South Indian Ocean Countercurrent was observed. This eastward frontal jet coincided with the barotropic and thermohaline front that separates the saline Subtropical Surface Water from the fresher Tropical Surface Water in the East Madagascar Current. The near-surface geostrophic flow of the East Madagascar Current, derived from satellite altimetry data from 1992 to 2005, suggests a strong variability of this transport due to eddy variability and interannual changes. The long-term pole-ward mean transport of the East Madagascar Current, roughly estimated from those altimetry data amounts to 32 Sv. The upper-ocean water mass of the East Madagascar Current was very saline in 2001, compared to WOCE surveys from 1995. Comparison of our undercurrent data with those of the WOCE surveys in 1995 confirms that the undercurrent is a recurrent feature. Its water mass properties are relatively saline, due to the presence of water originating from the Red Sea outflow at intermediate levels. The saline water was advected from the Mozambique Channel to the eastern slope of Madagascar.

The impacts of climate change on global irrigation water requirements

NASA Astrophysics Data System (ADS)

Zhang, X.; Cai, X.

2011-12-01

Climate change tends to affect the irrigation water requirement of current irrigated agricultural land, and also changes the water availability for current rain-fed land by the end of this century. We use the most up-to-date climatic and crop datasets (e.g., global irrigated/rain-fed crop areas and grid level crop growing calendar (Portmann, Siebert and Döll, 2010, Global Biogeochemical Cycles 24)) to evaluate the requirements of currently irrigated land and the water deficit for rain-fed land for all major crops under current and projected climate. Six general circulation models (GCMs) under two emission scenarios, A1B & B1, are assembled using two methods, the Simple Average Method (SAM) and Root Mean Square Error Ensemble Method (RMSEMM), to deal with the GCM regional variability. It is found that the global irrigation requirement and the water deficit are both going to increase significantly under all scenarios, particularly under the A1B emission scenario. For example, the projected irrigation requirement is expected to increase by about 2500 million m3 for wheat, 3200 million m3 for maize and another 3300 million m3 for rice. At the same time, the water deficit for current rain-fed cropland will be widened by around 3000, 4000, 2100 million m3 for wheat, maize and rice respectively. Regional analysis is conducted for Africa, China, Europe, India, South America and the United States. It is found that the U.S. may expect the greatest rise in irrigation requirements for wheat and maize, while the South America may suffer the greatest increase for rice. In addition, Africa and the U.S. may face a larger water deficit for both wheat and maize on rain-fed land, and South America just for rice. In summary, climate change is likely to bring severe challenges for irrigation systems and make global water shortage even worse by the end of this century. These pressures will call for extensive adaptation measures. The change in crop water requirements and availability will lead to changes in regional food production, demand and trade, and will affect global food markets. It is also likely that the network and paths of the so-called global virtual water flow will be altered due to the impact of climate change on food production at the regional level.

21 CFR 184.1139 - Ammonium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-finishing agent as defined in § 170.3(o)(30) of this chapter; and as a boiler water additive complying with... manufacturing practice. The ingredient may also be used as a boiler water additive at levels not to exceed... limitation other than current good manufacturing practice. The affirmation of this ingredient as generally...

MEETING IN CHARLOTTE: METHODS FOR THE ANALYSIS OF PRIORITY DBPS IN RO-CONCENTRATED DRINKING WATER

EPA Science Inventory

The ability to understand mechanisms of formation and occurrence of disinfection by-products (DBPs) resulting from treatment of natural waters has been limited to those formed at ug/L levels. Toxicological evaluations suggest that many of the DBPs missing from current regulation ...

Regenerating an Arsenic Removal Iron-Based Adsorptive Media System, Part 1: The Regeneration Process

EPA Science Inventory

Adsorptive media technology is a frequently used method of removing arsenic by small water systems because of its simplicity and efficiency. Current practice is to replace the media when it no longer reduces arsenic below the USEPA drinking water maximum contaminant level (MCL) ...

Credit BG. Interior view of the building displays temporary wooden ...

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

Credit BG. Interior view of the building displays temporary wooden building construction, pump, and water piping arrangements. The well is currently used as an observation post for changes in ground water levels - Edwards Air Force Base, North Base, Well No. 2, East of Second Street, Boron, Kern County, CA

Fouling-Resistant Membranes for Treating Concentrated Brines for Water Reuse in Advanced Energy Systems- Final Technical Report

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

Hendren, Zachary; Choi, Young Chul

The high total dissolved solids (TDS) levels in the wastewater quality generated from unconventional oil and gas development make the current state-of-the art approach to water treatment/disposal untenable. Our proposed membrane technology approach addresses the two major challenges associated with this water: 1) the membrane distillation process removes the high TDS content, which is often 8 times higher than that of seawater, and 2) our novel membrane coating prevents the formation of scale that would otherwise pose a significant operational hurdle. This is accomplished through next-generation electrically conductive membranes that mitigate fouling beyond what is currently possible, and allow formore » the flexibility to treat to the water to levels desirable for multiple reuse options, thus reducing fresh water withdrawal, all the way to direct disposal into the environment. The overall project objective was to demonstrate the efficacy of membrane distillation (MD) as a cost-savings technology to treat concentrated brines (such as, but not limited to, produced waters generated from fossil fuel extraction) that have high levels of TDS for beneficial water reuse in power production and other industrial operations as well as agricultural and municipal water uses. In addition, a novel fouling-resistant nanocomposite membrane was developed to reduce the need for chemicals to address membrane scaling due to the precipitation of divalent ions in high-TDS waters and improve overall MD performance via an electrically conductive membrane distillation process (ECMD). This anti-fouling membrane technology platform is based on incorporating carbon nanotubes (CNTs) into the surface layer of existing, commercially available MD membranes. The CNTs impart electrical conductivity to the membrane surface to prevent membrane scaling and fouling when an electrical potential is applied.« less

Water and the environment: a natural resource or a limited luxury?

PubMed

Leder, Karin; Sinclair, Martha I; McNeil, John J

The risk of contamination of drinking water supplies with microbial pathogens is minimised by modern approaches to water management, but continues to be the major public health concern. Chemical contaminants usually pose little health risk except at very high levels, but debate continues over the potential adverse health effects of low-level, chronic exposure to compounds such as disinfection byproducts. Recreational water contact can be associated with adverse health outcomes either from microbial infections or exposure to cyanobacterial toxins. Environmental issues such as increasing salinity and global warming are likely to affect the sustainability of our current drinking water supplies and increase the threat of waterborne disease outbreaks. New technologies, use of alternative water sources, such as rainwater tanks, water reuse and restrictions will undoubtedly be part of the solution to our diminishing water resources, but have the potential to introduce new health threats.

Observations of pockmark flow structure in Belfast Bay, Maine, Part 1: current-induced mixing

USGS Publications Warehouse

Fandel, Christina L.; Lippmann, Thomas C.; Irish, James D.; Brothers, Laura L.

2017-01-01

Field observations of current profiles and temperature, salinity, and density structure were used to examine vertical mixing within two pockmarks in Belfast Bay, Maine. The first is located in 21 m water depth (sea level to rim), nearly circular in shape with a 45 m rim diameter and 12 m rim-to-bottom relief. The second is located in 25 m water depth, more elongated in shape with an approximately 80 m (36 m) major (minor) axis length at the rim, and 17 m relief. Hourly averaged current profiles were acquired from bottom-mounted acoustic Doppler current profilers deployed on the rim and center of each pockmark over successive 42 h periods in July 2011. Conductivity–temperature–depth casts at the rim and center of each pockmark show warmer, fresher water in the upper water column, evidence of both active and fossil thermocline structure 5–8 m above the rim, and well-mixed water below the rim to the bottom. Vertical velocities show up- and down-welling events that extend into the depths of each pockmark. An observed temperature change at both the rim and center occurs coincident with an overturning event below the rim, and suggests active mixing of the water column into the depths of each pockmark. Vertical profiles of horizontal velocities show depth variation at both the center and rim consistent with turbulent logarithmic current boundary layers, and suggest that form drag may possibly be influencing the local flow regime. While resource limitations prevented observation of the current structure and water properties at a control site, the acquired data suggest that active mixing and overturning within the sampled pockmarks occur under typical benign conditions, and that current flows are influenced by upstream bathymetric irregularities induced by distant pockmarks.

On the Revealing Firsthand Probing of Ocean-Ice-Atmosphere Interactions off Sabrina Coast During NBP1402

NASA Astrophysics Data System (ADS)

Huber, B. A.; Orsi, A. H.; Zielinski, N. J.; Durkin, W. J., IV; Clark, P.; Wiederwohl, C. L.; Rosenberg, M. A.; Gwyther, D.; Greenbaum, J. S.; Lavoie, C.; Shevenell, A.; Leventer, A.; Blankenship, D. D.; Gulick, S. P. S.; Domack, E. W.

2014-12-01

Diverse interactions of winds, currents and ice around Antarctica dictate how, where and when the world's densest waters form and massive floating ice shelves and glaciers melt, as well as control sea surface gas exchange and primary productivity. Compelled by recent rate estimates of East Antarctic Ice Sheet mass loss, we contrast the paths and mixing histories of oceanic waters reaching the continental ice edge off the Sabrina and Adelie coasts relying on the unique set of synoptic shipboard measurements from NBP1402 (swath bathymetry, ADCP, underway CTD). Analysis of historical hydrography and sea ice concentration fields within the Mertz Polynya indicates the apparent effect of evolving ocean-ice-atmosphere interactions on the characteristics of local Shelf Water (SW) sources to current outflow of newly formed Antarctic Bottom Water (AABW). A polynya dominated water mass structure similar to that observed off the Adelie Coast before the removal of the Mertz Ice Tongue was expected to the west of the Dalton Ice Tongue (DIT). However, we found no evidence of dense SW off Sabrina Coast, which may lessen the region's preconceived influence to global meridional overturning. Present sea ice production within the eastern Dalton Polynya is overshadowed by freshwater input to relatively stable interior upper waters. The Antarctic Coastal Current (ACoC) picks up distinct meltwater contributions along the DIT western flank and in front of the Moscow University Ice Shelf (MUIS) and Totten Glacier (TG). Unlike over other highly influential margins to global sea level rise, there is no evidence of local cross-shelf inflow and mixing of warm Circumpolar Deep Water. Relatively cold thermocline waters from the continental slope enter the eastern trough off Sabrina Coast, and they are swiftly steered poleward by complex underlying topography. Meltwater export from beneath the MUIS and TG is observed at newly discovered trenches that effectively constrain sub-cavity inflow to low salinity near-freezing waters drawn from intermediate levels of the adjacent westward flowing ACoC. Winds, currents and ice interactions observed off Sabrina Coast during NBP1402 are most likely widespread, in view of reported decadal freshening of upper waters over the Antarctic continental shelf and their localized AABW outflows.

Annual summary of ground-water conditions in Arizona, spring 1975 to spring 1976

USGS Publications Warehouse

Babcock, H.M.

1977-01-01

Two small-scale maps of Arizona show (1) pumpage of ground water by areas and (2) the status of the ground-water inventory in the State. A larger map of the State at a scale of 1:500,000 shows potential well production, depth to water in selected wells in spring 1976, and change in water level in selected wells from 1971 to 1976. The brief text that accompanies the maps summarizes the current ground-water conditions in the State. The withdrawal of ground water in Arizona was about 5.6 million acre-feet in 1975, of which about 4.7 million acre-feet was used for the irrigation of crops. The Salt River Valley and the lower Santa Cruz basin are the largest agricultural areas in the State. For 1971-75, ground-water withdrawal in the two areas was about 8.3 and 4.7 million acre-feet, respectively, and, in general, water levels are declining. Other areas in which ground-water withdrawals have caused large water-level declines are the Willcox, San Simon, upper Santa Cruz, Avra Valley, Gila Bend, Harquahala Plains, and McMullen Valley areas. (Woodard-USGS)

Annual summary of ground-water conditions in Arizona, spring 1976 to spring 1977

USGS Publications Warehouse

Babcock, H.M.

1977-01-01

Two small-scale maps of Arizona show (1) pumpage of ground water by areas and (2) the status of the ground-water inventory in the State. The main map, which is at a scale of 1:500,000, shows potential well production, depth of water in selected wells in spring 1977, and change in water level in selected wells from 1972 to 1977. The brief text that accompanies the maps summarizes the current ground-water conditions in the State. The withdrawal of ground water was about 5.5 million acre-feet in Arizona in 1976 of which about 4.7 million acre-feet was used for the irrigation. The Salt River Valley and the lower Santa Cruz basin are the largest agricultural areas in the State. For 1972-76, ground-water withdrawal in the two areas was about 8.2 to 4.9 million acre-feet, respectively, and, in general, water levels are declining. Other areas in which ground-water withdrawals have caused large water-level declines are the Willcox, San Simon, upper Santa Cruz, Avra Valley, Gila Bend, Harquahala Plains, and McMullen Valley areas. (Woodard-USGS)

New insights on water level variability for Lake Turkana for the past 15 ka and at 150 ka from relict beaches

NASA Astrophysics Data System (ADS)

Forman, S. L.; Wright, D.

2015-12-01

Relict beaches adjacent to Lake Turkana provide a record of water level variability for the Late Quaternary. This study focused on deciphering the geomorphology, sedimentology, stratigraphy and 14C chronology of strand plain sequences in the Kalokol and Lothagam areas. Nine >30 m oscillations in water level were documented between ca. 15 and 4 ka. The earliest oscillation between ca. 14.5 and 13 ka is not well constrained with water level to at least 70 m above the present surface and subsequently fell to at least 50 m. Lake level increased to ~ 90 m between ca. 11.2 and 10.4 ka, post Younger Dryas cooling. Water level fell by >30 m by 10.2 ka, with another potential rise at ca. 8.5 ka to >70 m above current level. Lake level regressed by > 40 m at 8.2 ka coincident with cooling in the equatorial Eastern Atlantic Ocean. Two major >70 m lake level oscillations centered at 6.6 and 5.2 ka may reflect enhanced convection with warmer sea surface temperatures in the Western Indian Ocean. The end of the African Humid Period occurred from ca. 8.0 to 4.5 ka and was characterized by variable lake level (± > 40 m), rather than one monotonic fall in water level. This lake level variability reflects a complex response to variations in the extent and intensity of the East and West African Monsoons near geographic and topographic limits within the catchment of Lake Turkana. Also, for this closed lake basin excess and deficits in water input are amplified with a cascading lake effect in the East Rift Valley and through the Chew Bahir Basin. The final regression from a high stand of > 90 m began at. 5.2 ka and water level was below 20 m by 4.5 ka; and for the remainder of the Holocene. This sustained low stand is associated with weakening of the West African Monsoon, a shift of the mean position of Congo Air Boundary west of the Lake Turkana catchment and with meter-scale variability in lake level linked to Walker circulation across the Indian Ocean. A surprising observation is the presence of older, heavily dissected relict beaches up to 175 m above current lake level, which host beach rock and well developed carbonate rich soils. A preliminary OSL age of 145 ka, indicates that these surface are associated with MOI stage 6 and 5. The higher elevation of these beach either reflect tectonic up-warping, a change in elevation of the outlet to the Blue Nile or combination of these processes.

Hydrogeology, ground-water use, and ground-water levels in the Mill Creek Valley near Evendale, Ohio

USGS Publications Warehouse

Schalk, Charles; Schumann, Thomas

2002-01-01

Withdrawals of ground water in the central Mill Creek Valley near Evendale, Ohio, caused water-level declines of more than 100 feet by the 1950s. Since the 1950s, management practices have changed to reduce the withdrawals of ground water, and recovery of water levels in long-term monitoring wells in the valley has been documented. Changing conditions such as these prompted a survey of water use, streamflow conditions, and water levels in several aquifers in the central Mill Creek Valley, Hamilton and Butler Counties, Ohio. Geohydrologic information, water use, and water levels were compiled from historical records and collected during the regional survey. Data collected during the survey are presented in terms of updated geohydrologic information, water use in the study area, water levels in the aquifers, and interactions between ground water and surface water. Some of the data are concentrated at former Air Force Plant 36 (AFP36), which is collocated with the General Electric Aircraft Engines (GEAE) plant, and these data are used to describe geohydrology and water levels on a more local scale at and near the plant. A comparison of past and current ground-water use and levels indicates that the demand for ground water is decreasing and water levels are rising. Before 1955, most of the major industrial ground-water users had their own wells, ground water was mined from a confined surficial (lower) aquifer, and water levels were more than 100 feet below their predevelopment level. Since 1955, however, these users have been purchasing their water from the city of Cincinnati or a private water purveyor. The cities of Reading and Lockland, both producers of municipal ground-water supplies in the area, shut down their well fields within their city limits. Because the demand for ground-water supplies in the valley has lessened greatly since the 1950s, withdrawals have decreased, and, consequently, water levels in the lower aquifer are 65 to 105 feet higher than they were in 1955. During the time of the water-level survey (November 2000), ground water was being pumped from four locations in the lower aquifer, including three municipalities and one remediation site. Effects of pumping in those four areas were evident from the regional water-level data. Overall, the direction of ground-water flow in the lower aquifer is from northeast to southwest along the primary orientation of the Mill Creek Valley in the study area. Water levels in shallower surficial aquifers were mapped at local scales centered on GEAE. Examination of well logs indicated that these aquifers (called shallow and water-table) are discontinuous and, on a regional scale, few wells were completed in these aquifers. Water levels in the shallow aquifer indicated that flow was from northeast to southwest except in areas where pumping in the lower aquifer or the proximity of Mill Creek may have been affecting water levels in the shallow aquifer. Water levels in the water-table aquifer indicated flow toward Mill Creek from GEAE.

Drinking-Water Nitrate, Methemoglobinemia, and Global Burden of Disease: A Discussion

PubMed Central

Fewtrell, Lorna

2004-01-01

On behalf of the World Health Organization (WHO), I have undertaken a series of literature-based investigations examining the global burden of disease related to a number of environmental risk factors associated with drinking water. In this article I outline the investigation of drinking-water nitrate concentration and methemoglobinemia. The exposure assessment was based on levels of nitrate in drinking water greater than the WHO guideline value of 50 mg/L. No exposure–response relationship, however, could be identified that related drinking-water nitrate level to methemoglobinemia. Indeed, although it has previously been accepted that consumption of drinking water high in nitrates causes methemoglobinemia in infants, it appears now that nitrate may be one of a number of co-factors that play a sometimes complex role in causing the disease. I conclude that, given the apparently low incidence of possible water-related methemoglobinemia, the complex nature of the role of nitrates, and that of individual behavior, it is currently inappropriate to attempt to link illness rates with drinking-water nitrate levels. PMID:15471727

Integrated Modeling Approach for Verifying Water Storage Services for a Payment for Environmental Service Programs

NASA Astrophysics Data System (ADS)

Hendricks, G.; Shukla, S.; Guzha, A. C.

2013-12-01

Hydrologic models have been used for improved understanding of how an ecosystem's hydrologic response to human intervention and may provide substantial insight into the viability of payment for environmental services (PES) programs. Little is currently known about how hydrologic models can contribute to the design and evaluation of PES programs. Increased water storage is a desired environmental service (ES) for the Florida Everglades' watershed to reduce nutrient loads and excessive flows to lakes and estuaries in the region. We present monitoring and modeling results to verify the water storage PES for two ranch sites (wetland and watershed scales) located in the Northern Everglades region located north of the Lake Okeechobee (LO). Verification of the water storage PES using at least 3 years of hydrologic data was inconclusive due to variable rainfall during pre- and post-PES periods. An integrated surface and groundwater model, MIKE-SHE/MIKE11, was used to help verify the water storage service as well as predict ecological responses for different water storage scenarios (different levels of storage). The hydrological model was calibrated and validated using field measurements and was able to effectively simulate the surface and groundwater levels for the watershed (Nash Sutcliffe Efficiency, NSE = 0.54 to 0.82) and for surface water levels within wetlands (NSE = 0.54 to 0.84). Scenario analyses for storage levels showed an inverse relationship between board heights for water control structures and flows at the watershed outlet. Changes in flow were marginal when board heights approached a maximum indicating movement of water into subsurface storage. Combining simulation results with field measurements showed reduced flows and increased subsurface storage (2 cm/yr.), a desired outcome for protecting LO and estuarine systems from excessive flows. Simulated wetland water levels were combined with LIDAR-based topography to predict inundation for wetlands at the two PES sites for exploring the addition of biodiversity related ES. Simulations showed that effects of increased storage on enhanced hydro-periods and biodiversity was limited to the wetlands close to the drainage ditches. Results for a variety of water management scenarios showed that modeling can be used as an effective tool for optimizing the ES for a desired PES scheme. Measured and predicted surface flows from watershed and wetland water levels for different scenarios are currently being combined with ecological measurements to develop hydro-ecological models that predict the effects of enhanced water storage on ecological diversity.

Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system From Long Island, New York, to North Carolina

USGS Publications Warehouse

Masterson, John P.; Pope, Jason P.; Fienen, Michael N.; Monti, Jr., Jack; Nardi, Mark R.; Finkelstein, Jason S.

2016-08-31

Executive SummaryThe U.S. Geological Survey began a multiyear regional assessment of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system in 2010 as part of its ongoing regional assessments of groundwater availability of the principal aquifers of the Nation. The goals of this national assessment are to document effects of human activities on water levels and groundwater storage, explore climate variability effects on the regional water budget, and provide consistent and integrated information that is useful to those who use and manage the groundwater resource. As part of this nationwide assessment, the USGS evaluated available groundwater resources within the NACP aquifer system from Long Island, New York, to northeastern North Carolina.The northern Atlantic Coastal Plain physiographic province depends heavily on groundwater to meet agricultural, industrial, and municipal needs. The groundwater assessment of the NACP aquifer system included an evaluation of how water use has changed over time; this evaluation primarily used groundwater budgets and development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends.This assessment focused on multiple spatial and temporal scales to examine changes in groundwater pumping, storage, and water levels. The regional scale provides a broad view of the sources and demands on the system with time. The sub-regional scale provides an evaluation of the differing response of the aquifer system across geographic areas allowing for closer examination of the interaction between different aquifers and confining units and the changes in these interactions under pumping and recharge conditions in 2013 and hydrologic stresses as much as 45 years in the future. By focusing on multiple scales, water-resource managers may utilize this study to understand system response to changes as they affect the system as a whole.The NACP aquifer system extends from Long Island to northeastern North Carolina, and includes aquifers primarily within New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. The seaward-dipping sedimentary wedge that underlies the northern Atlantic Coastal Plain physiographic province forms a complex groundwater system. Although the NACP aquifer system is recognized by the U.S. Geological Survey as one of the smallest of the 66 principal aquifer systems in the Nation, it ranks 13th overall in terms of total groundwater withdrawals and is 7th in population served. Despite abundant precipitation [about 45 inches per year (in/yr)], the supply of fresh surface water in this region is limited because many of the surface waters in this area are brackish estuaries, contributing to why many communities in the northern Atlantic Coastal Plain physiographic province rely heavily on groundwater to meet their water needs.Increases in population and changes in land use during the past 100 years have resulted in diverse increased demands for freshwater throughout the northern Atlantic Coastal Plain physiographic province with groundwater serving as a vital source of drinking water for the nearly 20 million people who live in the region. Total groundwater withdrawal in 2013 was estimated to be about 1,300 million gallons per day (Mgal/d) and accounts for about 40 percent of the drinking water supply with the densely populated areas tending to have the highest rates of withdrawals and, therefore, being most susceptible to effects from these withdrawals over time.Water levels in many of the confined aquifers are decreasing by as much as 2 feet per year (ft/yr) in response to extensive development and subsequent increased withdrawals throughout the region. Total water-level decreases (drawdowns) are more than 100 feet (ft) in some aquifers from their predevelopment (before 1900) levels. These drawdowns extend across state lines and under the Chesapeake and Delaware Bays, creating the potential for interstate aquifer management issues. Regional water-resources managers in the northern Atlantic Coastal Plain physiographic province face challenges beyond competing local domestic, industrial, agricultural, and environmental demands for water. Large changes in regional water use have made the State-level management of aquifer resources more difficult because of hydrologic effects that extend beyond State boundaries.The northern Atlantic Coastal Plain physiographic province is underlain by a wedge of unconsolidated to partially consolidated sediments that are typically thousands of feet thick along the coastline with a maximum thickness of about 10,000 ft near the edge of the continental shelf. The NACP aquifer system consists of nine confined aquifers and nine confining units capped by an unconfined surficial aquifer that is bounded laterally from the west by the contact between Coastal Plain sediments and the upland Piedmont bedrock. This aquifer system extends to the east to the limit of the Continental Shelf, however, the boundary between fresh and saline groundwater is considered to be much closer to the shoreline and varies vertically by aquifer.Precipitation over the region for average conditions from 2005 to 2009 is about 61,800 Mgal/d, but about 70 percent of it is lost to evapotranspiration resulting in an inflow of about 19,600 Mgal/d entering the groundwater system as aquifer recharge. Most of this recharge enters the aquifer system and flows through the shallow unconfined aquifer and either discharges to streams or directly to coastal waters without reaching the deep, confined aquifer system. In addition to recharge from precipitation, other sources of water include the return of wastewater from domestic septic systems of about 240 Mgal/d, about 60 Mgal/d of water released from storage in the confined system, and about 30 Mgal/d of lateral inflow at the boundary between freshwater and saltwater in response to pumping for conditions in 2013.The outflow needed to balance the inflows was subdivided between streamflow, discharge to tidal portions of streams, and coastal discharge. The hydrologic budget developed for current [2013] conditions determined that 93 percent of the total outflow was to surface waters with about 70 percent divided evenly between streamflow and shallow coastal discharge and 23 percent as discharge to tidal waters. The remaining 7 percent of the total outflow components include withdrawals from both the surficial and confined aquifers of the groundwater system.The groundwater availability assessment of the NACP aquifer system highlights the importance of analyses at both the regional and local scales to understand how changes in land use, water use, and climate have affected groundwater resources and how these resources may change in the future. The investigation included assessments of the regional changes in water levels and budgets across State lines, the importance of considering storage change in the confining units, the response of the aquifer system to a continuation of current [2013] hydrologic stresses into the future, and the potential effects of climate change and sea-level rise on the aquifer system.The Potomac aquifer group includes two of the most widely used aquifers in the NACP aquifer system, the Potomac-Patapsco and Potomac-Patuxent regional aquifers, providing about 24 percent of the total groundwater used in the region. Withdrawals from large pumping centers in this deep, confined aquifer group have resulted in substantial decreases in water-levels across state lines, particularly between southern Virginia and northeastern North Carolina as well as between southern New Jersey and northern Delaware where water levels in the Potomac-Patapsco aquifer have decreased by as much as 200 ft and 50 ft, respectively from predevelopment to current [2013] conditions. This response in water levels also is reflected in changes in water budgets where, for example, about 20 percent of the total response to pumping in Virginia is met by inducing flow from adjacent States. Understanding and quantifying these hydrologic effects that extend beyond State boundaries is critical for the State- and regional-level management of aquifer resources.The cumulative storage loss from the intervening confining units throughout the entire NACP aquifer system was about 35 percent of the total storage loss from predevelopment to current [2013] conditions. In geographic areas such as Delmarva Peninsula, Maryland, and New Jersey, the water released from storage in the confining units makes up the majority of the total storage release from the groundwater system and is becoming proportionally more important over time as the surficial aquifer approaches equilibrium with respect to pumping and recharge stresses as of 2013.Storage loss from the confining units is of particular concern because, unlike in the sands that comprise the confined aquifers, water removed from the clayey confining unit sediments cannot be replenished as these units gradually compress. This non-recoverable storage loss, if great enough, can result in land subsidence where these units are thick and the release from storage is relatively large and contributes to increased concerns for sea-level rise in areas such as the lower portion of the Chesapeake Bay.Groundwater usage increased dramatically in the NACP aquifer system during post-World War II era from the mid-1940s to early the 1980s, with withdrawals increasing from about 400 Mgal/d to more than 1,300 Mgal/d. Although groundwater withdrawals have been relatively constant since the early 1980s, about half of the total groundwater withdrawn from the NACP aquifer system since 1900 was withdrawn in the past 30 years. An analysis of the response of the groundwater system to a continuation of the current [2013] pumping for an additional 30 years into the future shows that the flow system continues to adjust in terms of changes in water budget components, water levels, and the boundary between freshwater and saltwater as it approaches equilibrium. The largest change in water budget components is the reduction in the amount of water released from storage.Across the entire NACP aquifer system, the reduction of storage release from 7 to 4 percent of the total water budget change is accounted for by reductions in groundwater discharge to streams and coastal waters. Locally, a similar response is calculated for each of the geographic areas except for Virginia where the amount of water released from storage accounts for about 25 percent of the total change in water budget. This finding suggests that the groundwater flow system in Virginia is not approaching equilibrium under the current [2013] stresses and, therefore, water levels will continue to decrease even if the pumping remains constant.An analysis of the change in water levels in the Potomac-Patapsco aquifer as pumping is continued 30 years into the future reveals that the largest decreases in water levels throughout the NACP aquifer system will occur in the southern Virginia and northeastern North Carolina parts of the study area. It is these areas that also see the greatest potential for increased lateral movement of saline groundwater in the deep, confined portion of the groundwater flow system in response to a continuation of the current [2013] pumping rates.The potential effects of long-term climate change and variability on the hydrologic system and availability of water resources in the NACP aquifer system continue to be of serious societal concern. These concerns include the effects of changes in aquifer recharge and in sea-level rise on the groundwater flow system. An assessment of the potential effects of a prolonged drought during current [2013] pumping conditions indicated that the reductions in recharge associated with droughts, including additional irrigation withdrawals required to meet increased crop water demand, have the greatest effects on water levels and streamflows in the surficial aquifer, and changes in water levels in the confined aquifers primarily resulted from the increased withdrawals associated with increased irrigation pumping; this response was most apparent in the Delmarva Peninsula. These results suggest that water levels may not be susceptible to the effects of droughts in the confined aquifers of the NACP aquifer system not used for irrigation, unlike in the unconfined surficial aquifer.A second analysis also was conducted to assess the effects of sea-level rise on the groundwater system throughout the northern Atlantic Coastal Plain physiographic province because recent analyses of the relative rates of sea-level rise along the Atlantic coast indicate that the Mid-Atlantic region represents a hot spot with anomalously higher rates of sea-level rise than observed elsewhere in the United States. Groundwater levels rose from 0 to 3 ft in response to a 3-ft simulated change in sea-level position, with the largest response occurring along the shoreline and away from non-tidal streams. About 37 percent (or 10,000 square miles) of the area of the northern Atlantic Coastal Plain physiographic province may experience about a 0.5-ft or more increase in water levels with the 3-ft increase in sea-level position, whereas about 18 percent (almost 5,000 square miles) of land of the northern Atlantic Coastal Plain physiographic province may experience a 2-ft or more increase in water levels with the 3-ft increase in sea-level position.These increases in the water table are of particular concern in low-lying areas where the unsaturated (vadose) zone is already thin, thus creating concerns for groundwater inundation of subsurface infrastructure, such as basements, septic systems, and subway systems. This increase in the water table also will likely alter the distribution of groundwater discharge to surface-water bodies thus increasing groundwater flow to streams that would have otherwise discharged directly to coastal waters. Throughout the NACP aquifer system, this redistribution of groundwater discharge results in an additional 2 percent of base flow in streams. Although the increases in groundwater discharge to streams (and corresponding decreases in discharge to coastal waters) calculated for the entire NACP aquifer system and its geographic areas represent only a small increase compared with current [2013] conditions, this redistribution of groundwater discharge from the coast to streams locally can alter the delivery of freshwater input to coastal receiving waters and have ecohydrological implications on the sensitive ecosystems which rely on a balance of groundwater discharge and surface-water flow.

Summary of available hydrogeologic data for the northeast portion of the alluvial aquifer at Louisville, Kentucky

USGS Publications Warehouse

Unthank, Michael D.; Nelson, Hugh L.

2006-01-01

The hydrogeologic characteristics of the unconsolidated glacial outwash sand and gravel deposits that compose the northeast portion of the alluvial aquifer at Louisville, Kentucky, indicate a prolific water-bearing formation with approximately 7 billion gallons of ground-water storage and an estimated sustainable yield of over 280 million gallons per day. This abundance of ground water and the need to properly develop and manage this resource has prompted many past investigations (since 1956), which have produced reports, maps, and data files covering a variety of topics relative to the movement, availability, and use of ground water in this area. These data have been compiled into a single report to assist in future development and use of the ground-water resources. Available ground-water data for the alluvial aquifer at Louisville, Kentucky, from Beargrass Creek to Harrods Creek, were compiled from the U.S. Geological Survey National Water Information System and the Kentucky Groundwater Data Repository. Data contained in these databases include ground-water well-construction details and historical ground-water levels, drillers' logs, and water-quality information. Additional data and information were gathered from project files at the U.S. Geological Survey--Kentucky Water Science Center and files at the Louisville Water Company. Information contained in these files included data from area pumping tests describing aquifer characteristics and ground-water flow. Data describing current conditions of the ground-water system in the northeast portion of the alluvial aquifer also are included. Ground-water levels from a network of observation wells show recent trends in the flow system, and information from the Kentucky Division of Water-Groundwater Branch lists current permitted ground-water withdrawals in the area.

DEEP WATER ISOTOPIC CURRENT ANALYZER

DOEpatents

Johnston, W.H.

1964-04-21

A deepwater isotopic current analyzer, which employs radioactive isotopes for measurement of ocean currents at various levels beneath the sea, is described. The apparatus, which can determine the direction and velocity of liquid currents, comprises a shaft having a plurality of radiation detectors extending equidistant radially therefrom, means for releasing radioactive isotopes from the shaft, and means for determining the time required for the isotope to reach a particular detector. (AEC)

Performance analysis of a new hypersonic vitrector system.

PubMed

Stanga, Paulo Eduardo; Pastor-Idoate, Salvador; Zambrano, Isaac; Carlin, Paul; McLeod, David

2017-01-01

To evaluate porcine vitreous flow and water flow rates in a new prototype hypersonic vitrectomy system compared to currently available pneumatic guillotine vitrectors (GVs) systems. Two vitrectors were tested, a prototype, ultrasound-powered, hypersonic vitrector (HV) and a GV. Porcine vitreous was obtained within 12 to 24 h of sacrifice and kept at 4°C. A vial of vitreous or water was placed on a precision balance and its weight measured before and after the use of each vitrector. Test parameters included changes in aspiration levels, vitrector gauge, cut rates for GVs, % ultrasound (US) power for HVs, and port size for HVs. Data was analysed using linear regression and t-tests. There was no difference in the total average mean water flow between the 25-gauge GV and the 25-gauge HV (t-test: P = 0.363); however, 25-gauge GV was superior (t-test: P < 0.001) in vitreous flow. The 23-gauge GV was only more efficient in water and vitreous removal than 23-gauge HV needle-1 (Port 0.0055) (t-test: P < 0.001). For HV, wall thickness and gauge had no effect on flow rates. Water and vitreous flows showed a direct correlation with increasing aspiration levels and % US power (p<0.05). The HV produced consistent water and vitreous flow rates across the range of US power and aspiration levels tested. Hypersonic vitrectomy may be a promising new alternative to the currently available guillotine-based technologies.

Livestock ownership and microbial contamination of drinking-water: Evidence from nationally representative household surveys in Ghana, Nepal and Bangladesh.

PubMed

Wardrop, Nicola A; Hill, Allan G; Dzodzomenyo, Mawuli; Aryeetey, Genevieve; Wright, Jim A

2018-01-01

Current priorities for diarrhoeal disease prevention include use of sanitation and safe water. There have been few attempts to quantify the importance of animal faeces in drinking-water contamination, despite the presence of potentially water-borne zoonotic pathogens in animal faeces. This study aimed to quantify the relationship between livestock ownership and point-of-consumption drinking-water contamination. Data from nationally representative household surveys in Nepal, Bangladesh, and Ghana, each with associated water quality assessments, were used. Multinomial regression adjusting for confounders was applied to assess the relationship between livestock ownership and the level of drinking-water contamination with E. coli. Ownership of five or more large livestock (e.g. cattle) was significantly associated with drinking-water contamination in Ghana (RRR=7.9, 95% CI=1.6 to 38.9 for medium levels of contamination with 1-31cfu/100ml; RRR=5.2, 95% CI=1.1-24.5 for high levels of contamination with >31cfu/100ml) and Bangladesh (RRR=2.4, 95% CI=1.3-4.5 for medium levels of contamination; non-significant for high levels of contamination). Ownership of eight or more poultry (chickens, guinea fowl, ducks or turkeys) was associated with drinking-water contamination in Bangladesh (RRR=1.5, 95% CI=1.1-2.0 for medium levels of contamination, non-significant for high levels of contamination). These results suggest that livestock ownership is a significant risk factor for the contamination of drinking-water at the point of consumption. This indicates that addressing human sanitation without consideration of faecal contamination from livestock sources will not be sufficient to prevent drinking-water contamination. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Coherence between coastal and river flooding along the California coast

USGS Publications Warehouse

Odigie, Kingsley O.; Warrick, Jonathan

2018-01-01

Water levels around river mouths are intrinsically determined by sea level and river discharge. If storm-associated coastal water-level anomalies coincide with extreme river discharge, landscapes near river mouths will be flooded by the hydrodynamic interactions of these two water masses. Unfortunately, the temporal relationships between ocean and river water masses are not well understood. The coherence between extreme river discharge and coastal water levels at six California river mouths across different climatic and geographic regions was examined. Data from river gauges, wave buoys, and tide gauges from 2007 to 2014 were integrated to investigate the relationships between extreme river discharge and coastal water levels near the mouths of the Eel, Russian, San Lorenzo, Ventura, Arroyo Trabuco, and San Diego rivers. Results indicate that mean and extreme coastal water levels during extreme river discharge are significantly higher compared with background conditions. Elevated coastal water levels result from the combination of nontidal residuals (NTRs) and wave setups. Mean and extreme (>99th percentile of observations) NTRs are 3–20 cm and ∼30 cm higher during extreme river discharge conditions, respectively. Mean and extreme wave setups are up to 40 cm and ∼20–90 cm higher during extreme river discharge than typical conditions, respectively. These water-level anomalies were generally greatest for the northern rivers and least for the southern rivers. Time-series comparisons suggest that increases in NTRs are largely coherent with extreme river discharge, owing to the low atmospheric pressure systems associated with storms. The potential flooding risks of the concurrent timing of these water masses are tempered by the mixed, semidiurnal tides of the region that have amplitudes of 2–2.5 m. In summary, flooding hazard assessments for floodplains near California river mouths for current or future conditions with sea-level rise should include the temporal coherence of fluvial and oceanic water levels.

The characteristics and dynamics of wave-driven flow across a platform coral reef in the Red Sea

NASA Astrophysics Data System (ADS)

Lentz, S. J.; Churchill, J. H.; Davis, K. A.; Farrar, J. T.; Pineda, J.; Starczak, V.

2016-02-01

Current dynamics across a platform reef in the Red Sea near Jeddah, Saudi Arabia, are examined using 18 months of current profile, pressure, surface wave, and wind observations. The platform reef is 700 m long, 200 m across with spatial and temporal variations in water depth over the reef ranging from 0.6 to 1.6 m. Surface waves breaking at the seaward edge of the reef cause a 2-10 cm setup of sea level that drives cross-reef currents of 5-20 cm s-1. Bottom stress is a significant component of the wave setup balance in the surf zone. Over the reef flat, where waves are not breaking, the cross-reef pressure gradient associated with wave setup is balanced by bottom stress. The quadratic drag coefficient for the depth-average flow decreases with increasing water depth from Cda = 0.17 in 0.4 m of water to Cda = 0.03 in 1.2 m of water. The observed dependence of the drag coefficient on water depth is consistent with open-channel flow theory and a hydrodynamic roughness of zo = 0.06 m. A simple one-dimensional model driven by incident surface waves and wind stress accurately reproduces the observed depth-averaged cross-reef currents and a portion of the weaker along-reef currents over the focus reef and two other Red Sea platform reefs. The model indicates the cross-reef current is wave forced and the along-reef current is partially wind forced.

Promoting water hydraulics in Malaysia: A green educational approach

NASA Astrophysics Data System (ADS)

Yusof, Ahmad Anas; Zaili, Zarin Syukri; Hassan, Siti Nor Habibah; Tuan, Tee Boon; Saadun, Mohd Noor Asril; Ibrahim, Mohd Qadafie

2014-10-01

In promoting water hydraulics in Malaysia, this paper presents research development of water hydraulics educational training system for secondary and tertiary levels in Malaysia. Water hydraulics trainer with robotic attachment has been studied in order to promote the usefulness of such educational tools in promoting sustainability and green technology in the country. The trainer is being developed in order to allow constructive curriculum development and continuous marketing research for the effectiveness and usefulness of using water in hydraulic power trainer. The research on water-based hydraulic trainer is now possible with the current development in water hydraulics technology.

Running-induced patellofemoral pain fluctuates with changes in patella water content.

PubMed

Ho, Kai-Yu; Hu, Houchun H; Colletti, Patrick M; Powers, Christopher M

2014-01-01

Although increased bone water content resulting from repetitive patellofemoral joint loading has been suggested to be a possible mechanism underlying patellofemoral pain (PFP), there is little data to support this mechanism. The purpose of the current study was to determine whether running results in increases in patella water content and pain and whether 48 hours of rest reduces patella water content and pain to pre-running levels. Ten female runners with a diagnosis of PFP (mean age 25.1 years) participated. Patella water content was quantified using a chemical-shift-encoded water-fat magnetic resonance imaging (MRI) protocol. The visual analog scale (VAS) was used to quantify subjects' pain levels. MRI and pain data were obtained prior to running, immediately following a 40-minute running session, and 48 hours post-running. Pain and patella water content were compared among the 3 time points using one-way ANOVA's with repeated measures. Immediately post-running, persons with PFP reported significant increases in pain and exhibited elevated patella water content. Pain and patella water content decreased to pre-running levels following 48 hours of rest. Our findings suggest that transient changes in patella water content associated with running may, in part, contribute to patellofemoral symptoms.

Tidal dynamics in a changing lagoon: Flooding or not flooding the marginal regions

NASA Astrophysics Data System (ADS)

Lopes, Carina L.; Dias, João M.

2015-12-01

Coastal lagoons are low-lying systems under permanent changes motivated by natural and anthropogenic factors. Ria de Aveiro is such an example with its margins currently threatened by the advance of the lagoonal waters recorded during the last decades. This work aims to study the tidal modifications found between 1987 and 2012 in this lagoon, motivated by the main channels deepening which induce higher inland tidal levels. Additionally it aims to study the impact that protective walls designed to protect the margins against flooding may have in those modifications under sea level rise predictions. The hydrodynamic model ELCIRC previously calibrated for Ria de Aveiro was used and tidal asymmetry, tidal ellipses and residual currents were analyzed for different scenarios, considering the mean sea level rise predicted for 2100 and the implementation of probable flood protection walls. Results evidenced that lagoon dominance remained unchanged between 1987 and 2012, but distortion decreased/increased in the deeper/shallower channels. The same trend was found under mean sea level rise conditions. Tidal currents increased over this period inducing an amplification of the water properties exchange within the lagoon, which will be stronger under mean sea level rise conditions. The deviations between scenarios with or without flood protection walls can achieve 60% for the tidal distortion and residual currents and 20% for the tidal currents, highlighting that tidal properties are extremely sensitive to the lagoon geometry. In summary, the development of numerical modelling applications dedicated to study the influence of mean sea level rise on coastal low-lying systems subjected to human influence should include structural measures designed for flood defence in order to accurately predict changes in the local tidal properties.

Cellular water distribution, transport, and its investigation methods for plant-based food material.

PubMed

Khan, Md Imran H; Karim, M A

2017-09-01

Heterogeneous and hygroscopic characteristics of plant-based food material make it complex in structure, and therefore water distribution in its different cellular environments is very complex. There are three different cellular environments, namely the intercellular environment, the intracellular environment, and the cell wall environment inside the food structure. According to the bonding strength, intracellular water is defined as loosely bound water, cell wall water is categorized as strongly bound water, and intercellular water is known as free water (FW). During food drying, optimization of the heat and mass transfer process is crucial for the energy efficiency of the process and the quality of the product. For optimizing heat and mass transfer during food processing, understanding these three types of waters (strongly bound, loosely bound, and free water) in plant-based food material is essential. However, there are few studies that investigate cellular level water distribution and transport. As there is no direct method for determining the cellular level water distributions, various indirect methods have been applied to investigate the cellular level water distribution, and there is, as yet, no consensus on the appropriate method for measuring cellular level water in plant-based food material. Therefore, the main aim of this paper is to present a comprehensive review on the available methods to investigate the cellular level water, the characteristics of water at different cellular levels and its transport mechanism during drying. The effect of bound water transport on quality of food product is also discussed. This review article presents a comparative study of different methods that can be applied to investigate cellular water such as nuclear magnetic resonance (NMR), bioelectric impedance analysis (BIA), differential scanning calorimetry (DSC), and dilatometry. The article closes with a discussion of current challenges to investigating cellular water. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatially continuous interpolation of water stage and water depths using the Everglades depth estimation network (EDEN)

USGS Publications Warehouse

Pearlstine, Leonard; Higer, Aaron; Palaseanu, Monica; Fujisaki, Ikuko; Mazzotti, Frank

2007-01-01

The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level monitoring, ground-elevation modeling, and water-surface modeling that provides scientists and managers with current (2000-present), online water-stage and water-depth information for the entire freshwater portion of the Greater Everglades. Continuous daily spatial interpolations of the EDEN network stage data are presented on a 400-square-meter grid spacing. EDEN offers a consistent and documented dataset that can be used by scientists and managers to (1) guide large-scale field operations, (2) integrate hydrologic and ecological responses, and (3) support biological and ecological assessments that measure ecosystem responses to the implementation of the Comprehensive Everglades Restoration Plan (CERP) The target users are biologists and ecologists examining trophic level responses to hydrodynamic changes in the Everglades.

Analysis of projected water availability with current basin management plan, Pajaro Valley, California

USGS Publications Warehouse

Hanson, Randall T.; Lockwood, Brian; Schmid, Wolfgang

2014-01-01

The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations and assumptions of 2009 urban water demand and land use. Water supplied directly from precipitation, and indirectly from reuse, captured local runoff, and groundwater is necessary but inadequate to satisfy agricultural demand without coastal and regional storage depletion that facilitates seawater intrusion. These facilities reduce potential seawater intrusion by about 45% with groundwater levels in the four regions served by the CDS projected to recover to levels a few feet above sea level. The projected recoveries are not high enough to prevent additional seawater intrusion during dry-year periods or in the deeper aquifers where pumpage is greater. While these facilities could reduce coastal pumpage by about 55% of the historical 2000–2009 pumpage for these regions, and some of the water is delivered in excess of demand, other coastal regions continue to create demands on coastal pumpage that will need to be replaced to reduce seawater intrusion. In addition, inland urban and agricultural demands continue to sustain water levels below sea level causing regional landward gradients that also drive seawater intrusion. Seawater intrusion is reduced by about 45% but it supplies about 55% of the recovery of groundwater levels in the coastal regions served by the CDS. If economically feasible, water from summer agricultural runoff and tile-drain returnflows could be another potential local source of water that, if captured and reused, could offset the imbalance between supply and demand as well as reducing discharge of agricultural runoff into the National Marine Sanctuary of Monterey Bay. A BMP update (2012) identifies projects and programs that will fund a conservation program and will provide additional, alternative water sources to reduce or replace coastal and inland pumpage, and to replenish the aquifers with managed aquifer recharge in an inland portion of the Pajaro Valley.

Areas Contributing Recharge to Wells in the Tafuna-Leone Plain, Tutuila, American Samoa

USGS Publications Warehouse

Izuka, Scot K.; Perreault, Jeff A.; Presley, Todd K.

2007-01-01

To address the concerns about the potential for contamination of drinking-water wells in the Tafuna-Leone Plain, Tutuila, American Samoa, a numerical ground-water flow model was developed and used to delineate areas contributing recharge to the wells (ACRWs). Surveys and analyses were conducted to obtain or compile certain essential hydrogeologic information needed for the model, such as groundwater production statistics, ground-water levels under current production, and an assessment of the distribution of groundwater recharge. The ground-water surveys indicate that total production from all wells in the Tafuna-Leone Plain between 1985 and 2005 averaged 6.1 Mgal/d and showed a gradual increase. A synoptic survey indicates that current water levels in the Tafuna-Leone Plain are highest near its inland boundary, decrease toward the coast, and are slightly depressed in high-production well fields. Ground-water levels showed little effect from the increased production because hydraulic conductivites are high and withdrawal is small relative to recharge. Analysis of ground-water recharge using a soil water-budget analysis indicates that the Tafuna-Leone Plain and adjacent areas receive about 280 Mgal/d of water from rainfall, of which 24 percent runs off to the ocean, 26 percent is removed by evapotranspiration, and 50 percent goes to ground-water recharge. Ground-water recharge per unit area is generally higher at the mountain crests than at the coast, but the highest recharge per unit area is in the mountain-front recharge zone at the juncture between the Tafuna-Leone Plain and the adjacent mountains. Surface water from the mountains also contributes to ground-water recharge in the eastern Tafuna-Leone Plain, in a process analogous to mountain-front recharge described in arid areas. Analysis of stream-gage data indicates that in the mountains of Tutuila, ground water discharges and contributes substantially to the total flow of the streams. In contrast, multiple lines of evidence indicate that in the eastern Tafuna-Leone Plain, surface water recharges the highly permeable underlying aquifer. Steady-state model simulations representing current ground-water production conditions in the Tafuna-Leone Plain indicate that most ACRWs extend less than a mile from the production wells; thus, travel distance between any point within an ACRW and its well is short. A simulation representing a condition in which all wells are operating at maximum capacity resulted in larger ACRWs, which demonstrates that increasing ground-water withdrawal from existing wells, or building and developing new wells, increases the surface area that could potentially contribute contaminants. In some places, such as in Malaeimi Valley, water can travel quickly via surface-water routes to an area where the water can infiltrate within the ACRWs of a well field.

U.S. EPA Water Technology Innovation Cluster Leaders Meeting - "Successfully Supporting Early-Stage Companies: The Role of Technology Testing" Meeting Summary Report

EPA Science Inventory

The goals of this workshop were to: (1) increase the cluster leaders’ level of knowledge regarding past and current water technology testing programs, facilities and requirements; (2) learn from the experiences of technology vendors in getting innovative, commercial-ready product...

An integrated modeling framework for investigating water management practices in the ogallala aquifer region

USDA-ARS?s Scientific Manuscript database

The Ogallala aquifer region (OAR) currently accounts for 30% of total crop and animal production in the U.S. More than 90% of the water pumped from the Ogallala aquifer is used for irrigated agriculture in this region. Consequently, groundwater levels in the Ogallala aquifer are rapidly declining. H...

Evaluating confidence in the impact of regulatory nutrient reduction and assessing the competing impact of climate change

NASA Astrophysics Data System (ADS)

Irby, I.; Friedrichs, M. A. M.

2017-12-01

Human impacts on the Chesapeake Bay through increased nutrient run-off as a result of land-use change, urbanization, and industrialization, have resulted in a degradation of water quality over the last half-century. These direct impacts, compounded with human-induced climate changes such as warming, rising sea level, and changes in precipitation, have elevated the conversation surrounding the future of the Bay's water quality. As a result, in 2010, a Total Maximum Daily Load (TMDL) was established for the Chesapeake Bay that limited nutrient and sediment input in an effort to increase dissolved oxygen. This research utilizes a multiple model approach to evaluate confidence in the estuarine water quality modeling portion of the TMDL. One of the models is then used to assess the potential impact climate change may have on the success of currently mandated nutrient reduction levels in 2050. Results demonstrate that although the models examined differ structurally and in biogeochemical complexity, they project a similar attainment of regulatory water quality standards after nutrient reduction, while also establishing that meeting water quality standards is relatively independent of hydrologic conditions. By developing a Confidence Index, this research identifies the locations and causes of greatest uncertainty in modeled projections of water quality. Although there are specific locations and times where the models disagree, this research lends an increased degree of confidence in the appropriateness of the TMDL levels and in the general impact nutrient reductions will have on Chesapeake Bay water quality under current environmental conditions. However, when examining the potential impacts of climate change, this research shows that the combined impacts of increasing temperature, sea level, and river flow negatively affect dissolved oxygen throughout the Chesapeake Bay and impact progress towards meeting the water quality standards associated with the TMDL with increased temperature as the primary culprit. These results, having been continually shared with the regulatory TMDL modelers, will aid in the decision making for the 2017 TMDL Mid-Point Assessment.

Water quality of North Carolina streams

USGS Publications Warehouse

Harned, Douglas; Meyer, Dann

1983-01-01

Interpretation of water quality data collected by the U.S. Geological Survey and the North Carolina Department of Natural Resources and Community Development, for the Yadkin-Pee Dee River system, has identified water quality variations, characterized the current condition of the river in reference to water quality standards, estimated the degree of pollution caused by man, and evaluated long-term trends in concentrations of major dissolved constituents. Three stations, Yadkin River at Yadkin College (02116500), Rocky River near Norwood (02126000), and Pee Dee River near Rockingham (02129000) have been sampled over different periods of time beginning in 1906. Overall, the ambient water quality of the Yadkin-Pee Dee River system is satisfactory for most water uses. Iron and manganese concentrations are often above desirable levels, but they are not unusually high in comparison to other North Carolina streams. Lead concentrations also periodically rise above the recommended criterion for domestic water use. Mercury concentrations frequently exceed, and pH levels fall below, the recommended criteria for protection of aquatic life. Dissolved oxygen levels, while generally good, are lowest at the Pee Dee near Rockingham, due to the station 's location not far downstream from a lake. Suspended sediment is the most significant water quality problem of the Yadkin-Pee Dee River. The major cation in the river is sodium and the major anions are bicarbonate and carbonate. Eutrophication is currently a problem in the Yadkin-Pee Dee, particularly in High Rock Lake. An estimated nutrient and sediment balance of the system indicates that lakes along the Yadkin-Pee Dee River serve as a sink for sediment, ammonia, and phosphorus. Pollution makes up approximately 59% of the total dissolved solids load of the Yadkin River at Yadkin College, 43% for the Rocky River near Norwood, and 29% for the Pee Dee River near Rockingham. Statistically significant trends show a pattern of increasing concentration of most dissolved constituents over time, with a leveling off and decline in the middle to late 1970's.

Diffuse radiation increases global ecosystem-level water-use efficiency

NASA Astrophysics Data System (ADS)

Moffat, A. M.; Reichstein, M.; Cescatti, A.; Knohl, A.; Zaehle, S.

2012-12-01

Current environmental changes lead not only to rising atmospheric CO2 levels and air temperature but also to changes in air pollution and thus the light quality of the solar radiation reaching the land-surface. While rising CO2 levels are thought to enhance photosynthesis and closure of stomata, thus leading to relative water savings, the effect of diffuse radiation on transpiration by plants is less clear. It has been speculated that the stimulation of photosynthesis by increased levels of diffuse light may be counteracted by higher transpiration and consequently water depletion and drought stress. Ultimately, in water co-limited systems, the overall effect of diffuse radiation will depend on the sensitivity of canopy transpiration versus photosynthesis to diffuse light, i.e. whether water-use efficiency changes with relative levels of diffuse light. Our study shows that water-use efficiency increases significantly with higher fractions of diffuse light. It uses the ecosystem-atmosphere gas-exchange observations obtained with the eddy covariance method at 29 flux tower sites. In contrast to previous global studies, the analysis is based directly on measurements of diffuse radiation. Its effect on water-use efficiency was derived by analyzing the multivariate response of carbon and water fluxes to radiation and air humidity using a purely empirical approach based on artificial neural networks. We infer that per unit change of diffuse fraction the water-use efficiency increases up to 40% depending on diffuse fraction levels and ecosystem type. Hence, in regions with increasing diffuse radiation positive effects on primary production are expected even under conditions where water is co-limiting productivity.

Beneficial Use of Drilling Waste - A Wetland Restoration Technology

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

Pioneer Natural Resources

1999-07-01

The results obtained thus far are promising with regard to the low toxicity of restored drill cuttings (particularly the Cameron substrate) with increasing levels of salinity. Water extraction, acid digestion, and interstitial water samples from the restored drill cuttings, as well as redox potential, soil pH and interstitial nitrate/ammonium concentrations, and the photosynthetic response, have been determined for the baseline fresh water condition (June-August 1998), at 9ppt (September-November 1998), at 18ppt (December-February 1998,1999), and at 27ppt (currently underway). Salinities will be brought to full-strength seawater (36ppt) on May 24, 1999. The Cameron drill cuttings are remarkably similar to dredge spoil,more » which is currently being used as a wetland creation substrate. The few elements that were extracted into the interstitial water were primarily cations (Ca, K, Mg) and were not elevated to a level that would pose a threat to wetlands productivity. Swaco drill cuttings remained high in aluminum with concomitant high pH, which likely resulted in limited plant productivity through hindered nutrient uptake.« less

User requirements and user acceptance of current and next-generation satellite mission and sensor complement, oriented toward the monitoring of water resources

NASA Technical Reports Server (NTRS)

Castruccio, P. A.; Loats, H. L., Jr.; Fowler, T. R.; Robinson, P.

1975-01-01

Principal water resources users were surveyed to determine the applicability of remotely sensed data to their present and future requirements. Analysis of responses was used to assess the levels of adequacy of LANDSAT 1 and 2 in fulfilling hydrological functions, and to derive systems specifications for future water resources-oriented remote sensing satellite systems. The analysis indicates that water resources applications for all but the very large users require: (1) resolutions on the order of 15 meters, (2) a number of radiometric levels of the same order as currently used in LANDSAT 1 (64), (3) a number of spectral bands not in excess of those used in LANDSAT 1, and (4) a repetition frequency on the order of 2 weeks. The users had little feel for the value of new sensors (thermal IR, passive and active microwaves). What is needed in this area is to achieve specific demonstrations of the utility of these sensors and submit the results to the users to evince their judgement.

Sensitivity of water resources in the Delaware River basin to climate variability and change

USGS Publications Warehouse

Ayers, Mark A.; Wolock, David M.; McCabe, Gregory J.; Hay, Lauren E.; Tasker, Gary D.

1993-01-01

Because of the "greenhouse effect," projected increases in atmospheric carbon dioxide levels might cause global warming, which in turn could result in changes in precipitation patterns and evapotranspiration and in increases in sea level. This report describes the greenhouse effect; discusses the problems and uncertainties associated with the detection, prediction, and effects of climatic change, and presents the results of sensitivity-analysis studies of the potential effects of climate change on water resources in the Delaware River basin. On the basis of sensitivity analyses, potentially serious shortfalls of certain water resources in the basin could result if some climatic-change scenarios become true. The results of basin streamflow-model simulations in this study demonstrate the difficulty in distinguishing effects of climatic change on streamflow and water supply from effects of natural variability in current climate. The future direction of basin changes in most water resources, furthermore, cannot be determined precisely because of uncertainty in current projections of regional temperature and precipitation. This large uncertainty indicates that, for resource planning, information defining the sensitivities of water resources to a range of climate change is most relevant. The sensitivity analyses could be useful in developing contingency plans on how to evaluate and respond to changes, should they occur.

Physical and virtual water transfers for regional water stress alleviation in China

PubMed Central

Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R.; Guan, Dabo; Hubacek, Klaus

2015-01-01

Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management. PMID:25583516

Physical and virtual water transfers for regional water stress alleviation in China.

PubMed

Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R; Guan, Dabo; Hubacek, Klaus

2015-01-27

Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management.

Perchlorate Clinical Pharmacology and Human Health: A Review

PubMed Central

Soldin, Offie Porat; Braverman, Lewis E.; Lamm, Steven H.

2013-01-01

Summary Potassium perchlorate has been used at various times during the last 50 years to treat hyperthyroidism. Since World War II ammonium perchlorate has been used as a propellant for rockets. In 1997, the assay sensitivity for perchlorate in water was improved from 0.4 mg/L (ppm) to 4 µg/L (ppb). As a result, public water supplies in Southern California were found to contain perchlorate ions in the range of 5 to 8 ppb, and those in Southern Nevada were found to contain 5 to 24 ppb. Research programs have been developed to assess the safety or risk from these exposures and to assist state and regulatory agencies in setting a reasonable safe level for perchlorate in drinking water. This report reviews the evidence on the human health effects of perchlorate exposure. Perchlorate is a competitive inhibitor of iodine uptake. All of its pharmacologic effects at current therapeutic levels or lower are associated with inhibition of the sodium-iodide symporter (NIS) on the thyroid follicular cell membrane. A review of the medical and occupational studies has been undertaken to identify perchlorate exposure levels at which thyroid hormone levels may be reduced or thyrotropin levels increased. This exposure level may begin in the 35 to 100 mg/d range. Volunteer studies have been designed to determine the exposure levels at which perchlorate begins to affect iodine uptake in humans. Such effects may begin at levels of approximately 1 mg/d. Environmental studies have assessed the thyroidal health of newborns and adults at current environmental exposures to perchlorate and have concluded that the present levels appear to be safe. Whereas additional studies are underway both in laboratory animals and in the field, it appears that a safe level can be established for perchlorate in water and that regulatory agencies and others are now trying to determine that level. PMID:11477312

A Novel Application of Agent-based Modeling: Projecting Water Access and Availability Using a Coupled Hydrologic Agent-based Model in the Nzoia Basin, Kenya

NASA Astrophysics Data System (ADS)

Le, A.; Pricope, N. G.

2015-12-01

Projections indicate that increasing population density, food production, and urbanization in conjunction with changing climate conditions will place stress on water resource availability. As a result, a holistic understanding of current and future water resource distribution is necessary for creating strategies to identify the most sustainable means of accessing this resource. Currently, most water resource management strategies rely on the application of global climate predictions to physically based hydrologic models to understand potential changes in water availability. However, the need to focus on understanding community-level social behaviors that determine individual water usage is becoming increasingly evident, as predictions derived only from hydrologic models cannot accurately represent the coevolution of basin hydrology and human water and land usage. Models that are better equipped to represent the complexity and heterogeneity of human systems and satellite-derived products in place of or in conjunction with historic data significantly improve preexisting hydrologic model accuracy and application outcomes. We used a novel agent-based sociotechnical model that combines the Soil and Water Assessment Tool (SWAT) and Agent Analyst and applied it in the Nzoia Basin, an area in western Kenya that is becoming rapidly urbanized and industrialized. Informed by a combination of satellite-derived products and over 150 household surveys, the combined sociotechnical model provided unique insight into how populations self-organize and make decisions based on water availability. In addition, the model depicted how population organization and current management alter water availability currently and in the future.

Potential Effects of Climate Change on the Water Level, Flora and Macro-fauna of a Large Neotropical Wetland

PubMed Central

Úbeda, Bárbara; Di Giacomo, Adrian S.; Neiff, Juan José; Loiselle, Steven A.; Guadalupe Poi, Alicia S.; Gálvez, José Ángel; Casco, Silvina; Cózar, Andrés

2013-01-01

Possible consequences of climate change in one of the world’s largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds). On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species) was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer) around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication) presents an important challenge to the conservation of neotropical wetlands in the coming decades. PMID:23874446

Potential effects of climate change on the water level, flora and macro-fauna of a large neotropical wetland.

PubMed

Úbeda, Bárbara; Di Giacomo, Adrian S; Neiff, Juan José; Loiselle, Steven A; Poi, Alicia S Guadalupe; Gálvez, José Ángel; Casco, Silvina; Cózar, Andrés

2013-01-01

Possible consequences of climate change in one of the world's largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds). On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species) was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer) around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication) presents an important challenge to the conservation of neotropical wetlands in the coming decades.

Risk to Water Security on Small Islands

NASA Astrophysics Data System (ADS)

Holding, S. T.; Allen, D. M.

2013-12-01

The majority of fresh water available on small islands is shallow groundwater that forms a freshwater lens. Freshwater lenses are generally limited in extent and as such are vulnerable to many stressors that impact water security. These include stressors related to climate change, such as sea level rise, as well as those related to human impacts, such as contamination. Traditionally, water security assessments have focussed on indicators that provide a snapshot of the current condition. However, recent work suggests that in order to effectively manage the water system, it is also important to consider uncertain future impacts to the system by evaluating how different stressors might impact water security. In this study, a framework for assessing risk to water security was developed and tested on Andros Island in The Bahamas. The assessment comprises two main components that characterise the water system: numerical modelling studies and a hazard survey. A baseline numerical model of the freshwater lens throughout Andros Island was developed to simulate the morphology of the freshwater lens and estimate the freshwater resources currently available. The model was prepared using SEAWAT, a density-dependent flow and solute transport code. Various stressors were simulated in the model to evaluate the response of the freshwater lens to predicted future shifts in climate patterns, sea level rise, and changes in water use. A hazard survey was also conducted on the island to collect information related to the storage of contaminants, sanitation infrastructure, waste disposal practices and groundwater abstraction rates. The results of the survey form a geo-spatial database of the location and associated hazards to the freshwater lens. The resulting risk framework provides a ranking of overall risk to water security based on information from the numerical modelling and hazard survey. The risk framework is implemented in a Geographic Information System (GIS) and provides a map of the risk to water security throughout Andros Island. It evaluates risk to water security for current and future scenarios and will enable water resource managers to effectively adapt to future impacts on water security.

Flood-inundation maps for the Tippecanoe River near Delphi, Indiana

USGS Publications Warehouse

Menke, Chad D.; Bunch, Aubrey R.; Kim, Moon H.

2013-01-01

Digital flood-inundation maps for an 11-mile reach of the Tippecanoe River that extends from County Road W725N to State Road 18 below Oakdale Dam, Indiana (Ind.), were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent of flooding corresponding to selected water levels (stages) at USGS streamgage 03333050, Tippecanoe River near Delphi, Ind. Current conditions at the USGS streamgages in Indiana may be obtained online at http://waterdata.usgs.gov/in/nwis/current/?type=flow. In addition, the information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that are often co-located at USGS streamgages. That forecasted peak-stage information, also available on the Internet, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, water-surface profiles were simulated for the stream reach by means of a hydraulic one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relation at USGS streamgage 03333050, Tippecanoe River near Delphi, Ind., and USGS streamgage 03332605, Tippecanoe River below Oakdale Dam, Ind. The hydraulic model was then used to simulate 13 water-surface profiles for flood stages at 1-foot intervals reference to the streamgage datum and ranging from bankfull to approximately the highest recorded water level at the streamgage. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from Light Detection and Ranging (LiDAR) data) in order to delineate the area flooded at each water level. A flood inundation map was generated for each water-surface profile stage (13 maps in all) so that, for any given flood stage, users will be able to view the estimated area of inundation. The availability of these maps, along with current stage from USGS streamgages and forecasted stream stages from the NWS, provides emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

Modeling level change in Lake Urmia using hybrid artificial intelligence approaches

NASA Astrophysics Data System (ADS)

Esbati, M.; Ahmadieh Khanesar, M.; Shahzadi, Ali

2017-06-01

The investigation of water level fluctuations in lakes for protecting them regarding the importance of these water complexes in national and regional scales has found a special place among countries in recent years. The importance of the prediction of water level balance in Lake Urmia is necessary due to several-meter fluctuations in the last decade which help the prevention from possible future losses. For this purpose, in this paper, the performance of adaptive neuro-fuzzy inference system (ANFIS) for predicting the lake water level balance has been studied. In addition, for the training of the adaptive neuro-fuzzy inference system, particle swarm optimization (PSO) and hybrid backpropagation-recursive least square method algorithm have been used. Moreover, a hybrid method based on particle swarm optimization and recursive least square (PSO-RLS) training algorithm for the training of ANFIS structure is introduced. In order to have a more fare comparison, hybrid particle swarm optimization and gradient descent are also applied. The models have been trained, tested, and validated based on lake level data between 1991 and 2014. For performance evaluation, a comparison is made between these methods. Numerical results obtained show that the proposed methods with a reasonable error have a good performance in water level balance prediction. It is also clear that with continuing the current trend, Lake Urmia will experience more drop in the water level balance in the upcoming years.

Affordability of residential water tariffs: alternative measurement and explanatory factors in southern Spain.

PubMed

García-Valiñas, Maria A; Martínez-Espiñeira, Roberto; González-Gómez, Francisco

2010-12-01

Using information on a basic or "lifeline" level of domestic water use obtained from a water demand function based on a Stone-Geary utility function, a minimum water threshold of 128 m(3) per household per year was estimated in a sample of municipalities in Southern Spain. As a second objective, water affordability indexes were then calculated that relate the cost of such lifeline to average municipal income levels. The analysis of the factors behind the differences in that ratio across Andalusian municipalities shows that the relative cost of purchasing the lifeline appears inversely related to average income levels, revealing an element of regressivity in the component of water tariffs affecting the least superfluous part of the household's consumption. The main policy recommendation would involve redesigning water tariffs in order to improve access for lower income households to an amount of water sufficient to cover their basic needs. The proposed methodology could be applied to other geographical areas, both from developed and from developing countries, in order to analyze the degree of progressivity of the water tariffs currently in effect and in order to guide the design of more equitable regulatory policies. Copyright © 2010 Elsevier Ltd. All rights reserved.

Physical water scarcity metrics for monitoring progress towards SDG target 6.4: An evaluation of indicator 6.4.2 "Level of water stress".

PubMed

Vanham, D; Hoekstra, A Y; Wada, Y; Bouraoui, F; de Roo, A; Mekonnen, M M; van de Bund, W J; Batelaan, O; Pavelic, P; Bastiaanssen, W G M; Kummu, M; Rockström, J; Liu, J; Bisselink, B; Ronco, P; Pistocchi, A; Bidoglio, G

2018-02-01

Target 6.4 of the recently adopted Sustainable Development Goals (SDGs) deals with the reduction of water scarcity. To monitor progress towards this target, two indicators are used: Indicator 6.4.1 measuring water use efficiency and 6.4.2 measuring the level of water stress (WS). This paper aims to identify whether the currently proposed indicator 6.4.2 considers the different elements that need to be accounted for in a WS indicator. WS indicators compare water use with water availability. We identify seven essential elements: 1) both gross and net water abstraction (or withdrawal) provide important information to understand WS; 2) WS indicators need to incorporate environmental flow requirements (EFR); 3) temporal and 4) spatial disaggregation is required in a WS assessment; 5) both renewable surface water and groundwater resources, including their interaction, need to be accounted for as renewable water availability; 6) alternative available water resources need to be accounted for as well, like fossil groundwater and desalinated water; 7) WS indicators need to account for water storage in reservoirs, water recycling and managed aquifer recharge. Indicator 6.4.2 considers many of these elements, but there is need for improvement. It is recommended that WS is measured based on net abstraction as well, in addition to currently only measuring WS based on gross abstraction. It does incorporate EFR. Temporal and spatial disaggregation is indeed defined as a goal in more advanced monitoring levels, in which it is also called for a differentiation between surface and groundwater resources. However, regarding element 6 and 7 there are some shortcomings for which we provide recommendations. In addition, indicator 6.4.2 is only one indicator, which monitors blue WS, but does not give information on green or green-blue water scarcity or on water quality. Within the SDG indicator framework, some of these topics are covered with other indicators. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Biomonitoring of water quality of the Osumi, Devolli, and Shkumbini rivers through benthic macroinvertebrates and chemical parameters.

PubMed

Duka, Sonila; Pepa, Bledar; Keci, Erjola; Paparisto, Anila; Lazo, Pranvera

2017-04-16

Environmental monitoring of river water quality in Albania, using biological and chemical parameters, is a fast and effective way to assess the quality of water bodies.The aim of this study was to investigate Ephemeroptera, Plecoptera and Trichoptera (EPT), Biotic index-Richness using macroinvertebrates to assess the water quality, with special reference to nutrient (phosphorus and nitrogen) levels in the Devolli, Shkumbini and Osumi rivers. Our objective was to investigate the relationships between the measures of benthic macroinvertebrate communities and nutrient concentrations to assess water quality. The rivers' benthic macroinvertebrates were collected during different seasons in 2012. The biological and chemical parameters used in the current study identified them as quick indicators of water quality assessment. The total number of macroinvertebrate individuals (n = 15,006) (Osumi river: n = 5,546 organisms; Devolli river: n = 3,469 organisms; and Shkumbini river: n = 5,991 organisms), together with the EPT group (Ephemeroptera, Plecoptera, and Trichoptera), showed that the water quality at the river stations during the above-mentioned period belonged to Classes II and III (fair water quality and good water quality, respectively). The classification of the water quality was also based on the nitrogen and total phosphorus contents. The pollution tolerance levels of macroinvertebrate taxa varied from the non-tolerating forms encountered in environments with low pollution levels to the tolerating forms that are typical of environments with considerable pollution levels.

Advanced Technologies to Improve Closure of Life Support Systems

NASA Technical Reports Server (NTRS)

Barta, Daniel J.

2016-01-01

As NASA looks beyond the International Space Station toward long-duration, deep space missions away from Earth, the current practice of supplying consumables and spares will not be practical nor affordable. New approaches are sought for life support and habitation systems that will reduce dependency on Earth and increase mission sustainability. To reduce launch mass, further closure of Environmental Control and Life Support Systems (ECLSS) beyond the current capability of the ISS will be required. Areas of particular interest include achieving higher degrees of recycling within Atmosphere Revitalization, Water Recovery and Waste Management Systems. NASA is currently investigating advanced carbon dioxide reduction processes that surpass the level of oxygen recovery available from the Sabatier Carbon Dioxide Reduction Assembly (CRA) on the ISS. Candidate technologies will potentially improve the recovery of oxygen from about 50% (for the CRA) to as much as 100% for technologies who's end product is solid carbon. Improving the efficiency of water recycling and recovery can be achieved by the addition of advanced technologies to recover water from brines and solid wastes. Bioregenerative technologies may be utilized for water reclaimation and also for the production of food. Use of higher plants will simultaneously benefit atmosphere revitalization and water recovery through photosynthesis and transpiration. The level at which bioregenerative technologies are utilized will depend on their comparative requirements for spacecraft resources including mass, power, volume, heat rejection, crew time and reliability. Planetary protection requirements will need to be considered for missions to other solar system bodies.

Flood-inundation maps for the Driftwood River and Sugar Creek near Edinburgh, Indiana

USGS Publications Warehouse

Fowler, Kathleen K.; Kim, Moon H.; Menke, Chad D.

2012-01-01

Digital flood-inundation maps for an 11.2 mile reach of the Driftwood River and a 5.2 mile reach of Sugar Creek, both near Edinburgh, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Camp Atterbury Joint Maneuver Training Center, Edinburgh, Indiana. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent of flooding corresponding to selected water levels (stages) at the USGS streamgage 03363000 Driftwood River near Edinburgh, Ind. Current conditions at the USGS streamgage in Indiana may be obtained on the Internet at http://waterdata.usgs.gov/in/nwis/current/?type=flow. In addition, the information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system at http://water.weather.gov/ahps/. The NWS forecasts flood hydrographs at many places that are often collocated at USGS streamgages. That forecasted peak-stage information, also available on the Internet, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. For this study, flood profiles were computed for the stream reaches by means of a one-dimensional step-backwater model. The model was calibrated using the most current stage-discharge relations at the USGS streamgage 03363000 Driftwood River near Edinburgh, Ind. The hydraulic model was then used to determine elevations throughout the study reaches for nine water-surface profiles for flood stages at 1-ft intervals referenced to the streamgage datum and ranging from bankfull to nearly the highest recorded water level at the USGS streamgage 03363000 Driftwood River near Edinburgh, Ind. The simulated water-surface profiles were then combined with a geospatial digital elevation model (derived from Light Detection and Ranging (LiDAR) data) in order to delineate the area flooded at each water level. The availability of these maps along with real-time information available online regarding current stage from USGS streamgages and forecasted stream stages from the NWS provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post flood recovery efforts.

Hydrogeologic Setting and Ground-Water Flow in the Leetown Area, West Virginia

USGS Publications Warehouse

Kozar, Mark D.; Weary, David J.; Paybins, Katherine S.; Pierce, Herbert A.

2007-01-01

The Leetown Science Center is a research facility operated by the U.S. Geological Survey that occupies approximately 455-acres near Kearneysville, Jefferson County, West Virginia. Aquatic and fish research conducted at the Center requires adequate supplies of high-quality, cold ground water. Three large springs and three production wells currently (in 2006) supply water to the Center. The recent construction of a second research facility (National Center for Cool and Cold Water Aquaculture) operated by the U.S. Department of Agriculture and co-located on Center property has placed additional demands on available water resources in the area. A three-dimensional steady-state finite-difference ground-water flow model was developed to simulate ground-water flow in the Leetown area and was used to assess the availability of ground water to sustain current and anticipated future demands. The model also was developed to test a conceptual model of ground-water flow in the complex karst aquifer system in the Leetown area. Due to the complexity of the karst aquifer system, a multidisciplinary research study was required to define the hydrogeologic setting. Geologic mapping, surface- and borehole-geophysical surveys, stream base-flow surveys, and aquifer tests were conducted to provide the hydrogeologic data necessary to develop and calibrate the model. It would not have been possible to develop a numerical model of the study area without the intensive data collection and methods developments components of the larger, more comprehensive hydrogeologic investigation. Results of geologic mapping and surface-geophysical surveys verified the presence of several prominent thrust faults and identified additional faults and other complex geologic structures (including overturned anticlines and synclines) in the area. These geologic structures are known to control ground-water flow in the region. Results of this study indicate that cross-strike faults and fracture zones are major avenues of ground-water flow. Prior to this investigation, the conceptual model of ground-water flow for the region focused primarily on bedding planes and strike-parallel faults and joints as controls on ground-water flow but did not recognize the importance of cross-strike faults and fracture zones that allow ground water to flow downgradient across or through less permeable geologic formations. Results of the ground-water flow simulation indicate that current operations at the Center do not substantially affect either streamflow (less than a 5-percent reduction in annual streamflow) or ground-water levels in the Leetown area under normal climatic conditions but potentially could have greater effects on streamflow during long-term drought (reduction in streamflow of approximately 14 percent). On the basis of simulation results, ground-water withdrawals based on the anticipated need for an additional 150 to 200 gal/min (gallons per minute) of water at the Center also would not seriously affect streamflow (less than 8 to 9 percent reduction in streamflow) or ground-water levels in the area during normal climatic conditions. During drought conditions, however, the effects of current ground-water withdrawals and anticipated additional withdrawals of 150 to 200 gal/min to augment existing supplies result in moderate to substantial declines in water levels of 0.5-1.2 feet (ft) in the vicinity of the Center's springs and production wells. Streamflow was predicted to be reduced locally by approximately 21 percent. Such withdrawals during a drought or prolonged period of below normal ground-water levels would result in substantial declines in the flow of the Center's springs and likely would not be sustainable for more than a few months. The drought simulated in this model was roughly equivalent to the more than 1-year drought that affected the region from November 1998 through February 2000. The potential reduction in streamflow is a result of capture of ground water tha

Effects of iron on arsenic speciation and redox chemistry in acid mine water

USGS Publications Warehouse

Bednar, A.J.; Garbarino, J.R.; Ranville, J.F.; Wildeman, T.R.

2005-01-01

Concern about arsenic is increasing throughout the world, including areas of the United States. Elevated levels of arsenic above current drinking-water regulations in ground and surface water can be the result of purely natural phenomena, but often are due to anthropogenic activities, such as mining and agriculture. The current study correlates arsenic speciation in acid mine drainage and mining-influenced water with the important water-chemistry properties Eh, pH, and iron(III) concentration. The results show that arsenic speciation is generally in equilibrium with iron chemistry in low pH AMD, which is often not the case in other natural-water matrices. High pH mine waters and groundwater do not always hold to the redox predictions as well as low pH AMD samples. The oxidation and precipitation of oxyhydroxides deplete iron from some systems, and also affect arsenite and arsenate concentrations through sorption processes. ?? 2004 Elsevier B.V. All rights reserved.

A numerical study on the effects of wave-current-surge interactions on the height and propagation of sea surface waves in Charleston Harbor during Hurricane Hugo 1989

NASA Astrophysics Data System (ADS)

Liu, Huiqing; Xie, Lian

2009-06-01

The effects of wave-current interactions on ocean surface waves induced by Hurricane Hugo in and around the Charleston Harbor and its adjacent coastal waters are examined by using a three-dimensional (3D) wave-current coupled modeling system. The 3D storm surge modeling component of the coupled system is based on the Princeton Ocean Model (POM), the wave modeling component is based on the third generation wave model, Simulating WAves Nearshore (SWAN), and the inundation model is adopted from [Xie, L., Pietrafesa, L. J., Peng, M., 2004. Incorporation of a mass-conserving inundation scheme into a three-dimensional storm surge model. J. Coastal Res., 20, 1209-1223]. The results indicate that the change of water level associated with the storm surge is the primary cause for wave height changes due to wave-surge interaction. Meanwhile, waves propagating on top of surge cause a feedback effect on the surge height by modulating the surface wind stress and bottom stress. This effect is significant in shallow coastal waters, but relatively small in offshore deep waters. The influence of wave-current interaction on wave propagation is relatively insignificant, since waves generally propagate in the direction of the surface currents driven by winds. Wave-current interactions also affect the surface waves as a result of inundation and drying induced by the storm. Waves break as waters retreat in regions of drying, whereas waves are generated in flooded regions where no waves would have occurred without the flood water.

Coastal tomographic mapping of nonlinear tidal currents and residual currents

NASA Astrophysics Data System (ADS)

Zhu, Ze-Nan; Zhu, Xiao-Hua; Guo, Xinyu

2017-07-01

Depth-averaged current data, which were obtained by coastal acoustic tomography (CAT) July 12-13, 2009 in Zhitouyang Bay on the western side of the East China Sea, are used to estimate the semidiurnal tidal current (M2) as well as its first two overtide currents (M4 and M6). Spatial mean amplitude ratios M2:M4:M6 in the bay are 1.00:0.15:0.11. The shallow-water equations are used to analyze the generation mechanisms of M4 and M6. In the deep area, where water depths are larger than 60 m, M4 velocity amplitudes measured by CAT agree well with those predicted by the advection terms in the shallow water equations, indicating that M4 in the deep area is predominantly generated by the advection terms. M6 measured by CAT and M6 predicted by the nonlinear quadratic bottom friction terms agree well in the area where water depths are less than 20 m, indicating that friction mechanisms are predominant for generating M6 in the shallow area. In addition, dynamic analysis of the residual currents using the tidally averaged momentum equation shows that spatial mean values of the horizontal pressure gradient due to residual sea level and of the advection of residual currents together contribute about 75% of the spatial mean values of the advection by the tidal currents, indicating that residual currents in this bay are induced mainly by the nonlinear effects of tidal currents. This is the first ever nonlinear tidal current study by CAT.

Impacts of climate change and anthropization on groundwater resources in the Nouakchott urban area (coastal Mauritania)

NASA Astrophysics Data System (ADS)

Mohamed, Ahmed-Salem; Leduc, Christian; Marlin, Christelle; Wagué, Oumar; Sidi Cheikh, Mohamed-Ahmed

2017-10-01

Declining groundwater resources in semi-arid areas are often cited because of anthropization and climate change. This is not the case in Nouakchott (Mauritania) where the water level has risen by 1 to 2 m over the last 40 years in parallel with urban expansion (+1 million inhabitants in 60 years). Using former and new data, primarily water table measurements and chemical indicators (major ions, bromide, 18O, 2H), we show that the groundwater level rise is mainly a consequence of the rapid population growth in the Nouakchott area, while the global sea level rise only has a limited impact. The increased supply of domestic water (currently 120,000 m3/day) and the lack of waste water networks have added large amounts of water to the Quaternary aquifer. In this metropolis where 60% of the total area is at an elevation of less than 1 m asl, the rise in the groundwater level has dramatic consequences, including the abandonment of flooded districts, and the emergence of new diseases.

Hydrogeology and groundwater availability in Clarke County, Virginia

USGS Publications Warehouse

Nelms, David L.; Moberg, Roger M.

2010-01-01

The prolonged drought between 1999 and 2002 drew attention in Clarke County, Virginia, to the quantity and sustainability of its groundwater resources. The groundwater flow systems of the county are complex and are controlled by the extremely folded and faulted geology that underlies the county. A study was conducted between October 2002 and October 2008 by the U.S. Geological Survey, in cooperation with Clarke County, Virginia, to describe the hydrogeology and groundwater availability in the county and to establish a long-term water monitoring network. The study area encompasses approximately 177 square miles and includes the carbonate and siliciclastic rocks of the Great Valley section of the Valley and Ridge Physiographic Province and the metamorphic rocks of the Blue Ridge Physiographic Province (Blue Ridge). High-yielding wells generally tend to cluster along faults, within lineament zones, and in areas of tight folding throughout the county. Water-bearing zones are generally within 250 feet (ft) of land surface; however, median depths are slightly deeper for the hydrogeologic units of the Blue Ridge than for those of the Great Valley section of the county. Total water-level fluctuations between October 2002 and October 2008 ranged from 2.86 to 87.84 ft across the study area, with an average of 24.15 ft. Generally, water-level fluctuations were greatest near hydrologic divides, in isolated elevated areas, and in the Opequon Creek Basin. Seasonally, water-level highs occur in the early spring at the end of the major groundwater recharge period and lows occur in late autumn when evapotranspiration rates begin to decrease. An overall downward trend in water levels between 2003 and 2008, which closely follows a downward trend in annual precipitation over the same period, was observed in a majority of wells in the Great Valley and in some of the wells in the Blue Ridge. Water-level fluctuations in the Blue Ridge tend to follow current meteorological conditions, and seasonal highs and lows tend to shift in response to the current conditions. Springs generally are present along faults and fold axes, and discharges for the study period ranged from dry to 10 cubic feet per second. A similar downward trend in discharges correlates with the trend in water levels and is indicative of an aquifer system that, over time, drains to a base level controlled by springs and streams. Point discharge from springs can occur as the start of flows of streams and creeks, along banks, and as discrete discharge through streambeds in the Great Valley. For the most part, streams, creeks, and rivers in the Great Valley function as aqueducts. Springs in the Blue Ridge have relatively low discharge rates, have small drainage areas, and are susceptible to current meteorological conditions. Estimates of effective groundwater recharge from 2001 to 2007 ranged from 6.4 to 23.0 inches per year (in/yr) in the Dry Marsh Run and Spout Run Basins with averages of 11.6 and 11.9 in/yr, respectively. Base flow accounted for between 80 and 97 percent of mean streamflow and averaged about 90 percent in these basins. The high base-flow index values (percent of streamflow from base flow) in the Dry Marsh Run and Spout Run Basins indicate that groundwater is the dominant source of streamflow during both wet and drought conditions. Between 46 and 82 percent of the precipitation that fell on the Dry Marsh Run and Spout Run Basins from 2001 to 2007 was removed by evapotranspiration, and an average of approximately 30 percent of the precipitation reached the water table as effective recharge. The high permeability of the rocks and low relief in these basins are not conducive for runoff; therefore, on average, only about 3 to 4 percent of the precipitation becomes runoff. Groundwater flow systems in the county are extremely vulnerable to current climatic conditions. Successive years of below-average effective recharge cause declines in water levels, spring discha

Prototype Continuous Flow Ventricular Assist Device Supported on Magnetic Bearings.

PubMed

Allaire, P E; Kim, H C; Maslen, E H; Olsen, D B; Bearnson, G B

1996-05-01

This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells. © 1996 International Society for Artificial Organs.

Effects of Withdrawals on Ground-Water Levels in Southern Maryland and the Adjacent Eastern Shore, 1980-2005

USGS Publications Warehouse

Soeder, Daniel J.; Raffensperger, Jeff P.; Nardi, Mark R.

2007-01-01

Ground water is the primary source of water supply in most areas of Maryland?s Atlantic Coastal Plain, including Southern Maryland. The counties in this area are experiencing some of the most rapid growth and development in the State, resulting in an increased demand for ground-water production. The cooperative, basic water-data program of the U.S. Geological Survey and the Maryland Geological Survey has collected long-term observations of ground-water levels in Southern Maryland and parts of the Eastern Shore for many decades. Additional water-level observations were made by both agencies beginning in the 1970s, under the Power Plant Research Program of the Maryland Department of Natural Resources. These long-term water levels commonly show significant declines over several decades, which are attributed to ground-water withdrawals. Ground-water-level trends since 1980 in major Coastal Plain aquifers such as the Piney Point-Nanjemoy, Aquia, Magothy, upper Patapsco, lower Patapsco, and Patuxent were compared to water use and withdrawal data. Potentiometric surface maps show that most of the declines in ground-water levels can be directly related to effects from major pumping centers. There is also evidence that deep drawdowns in some pumped aquifers may be causing declines in adjacent, unpumped aquifers. Water-level hydrographs of many wells in Southern Maryland show linear declines in levels year after year, instead of the gradual leveling-off that would be expected as the aquifers equilibrate with pumping. A continual increase in the volumes of water being withdrawn from the aquifers is one explanation for why they are not reaching equilibrium. Although reported ground-water production in Southern Maryland has increased somewhat over the past several decades, the reported increases are often not large enough to account for the observed water-level declines. Numerical modeling simulations indicate that a steady, annual increase in the number of small wells could account for the observed aquifer behavior. Such wells, being pumped at rates below the minimum legal reporting threshold of 10,000 gallons per day, might be the source of the additional withdrawals. More detailed water-use data, especially from domestic wells, central-pivot irrigation wells, and other small users not currently reporting withdrawals to the State, may help to determine the cause of the aquifer declines.

Evolution of regulatory targets for drinking water quality.

PubMed

Sinclair, Martha; O'Toole, Joanne; Gibney, Katherine; Leder, Karin

2015-06-01

The last century has been marked by major advances in the understanding of microbial disease risks from water supplies and significant changes in expectations of drinking water safety. The focus of drinking water quality regulation has moved progressively from simple prevention of detectable waterborne outbreaks towards adoption of health-based targets that aim to reduce infection and disease to a level well below detection limits at the community level. This review outlines the changes in understanding of community disease and waterborne risks that prompted development of these targets, and also describes their underlying assumptions and current context. Issues regarding the appropriateness of selected target values, and how continuing changes in knowledge and practice may influence their evolution, are also discussed.

Occurrence and sources of bromate in chlorinated tap drinking water in Metropolitan Manila, Philippines.

PubMed

Genuino, Homer C; Espino, Maria Pythias B

2012-04-01

Significant levels of potentially carcinogenic bromate were measured in chlorinated tap drinking water in Metropolitan Manila, Philippines, using an optimized ion-chromatographic method. This method can quantify bromate in water down to 4.5 μg l⁻¹ by employing a postcolumn reaction with acidic fuchsin and subsequent spectrophotometric detection. The concentration of bromate in tap drinking water samples collected from 21 locations in cities and municipalities within the 9-month study period ranged from 7 to 138 μg l⁻¹. The average bromate concentration of all tap drinking water samples was 66 μg l⁻¹ (n = 567), almost seven times greater than the current regulatory limit in the country. The levels of bromate in other water types were also determined to identify the sources of bromate found in the distribution lines and to further uncover contaminated sites. The concentration of bromate in water sourced from two rivers and two water treatment plants ranged from 15 to 80 and 12 to 101 μg l⁻¹, respectively. Rainwater did not contribute bromate in rivers but decreased bromate level by dilution. Groundwater and wastewater samples showed bromate concentrations as high as 246 and 342 μg l⁻¹, respectively. Bromate presence in tap drinking water can be linked to pollution in natural water bodies and the practice of using hypochlorite chemicals in addition to gaseous chlorine for water disinfection. This study established the levels, occurrence, and possible sources of bromate in local drinking water supplies.

Hydrologic Conditions in Kansas, water year 2015

USGS Publications Warehouse

May, Madison R.

2016-03-31

The U.S. Geological Survey (USGS), in cooperation with Federal, State, and local agencies, maintains a long-term network of hydrologic monitoring sites in Kansas. In 2015, the network included about 200 real-time streamgages (hereafter referred to as “gages”), 12 real-time reservoir-level monitoring stations, and 30 groundwater-level monitoring wells. These data and associated analyses provide a unique overview of hydrologic conditions and help improve the understanding of Kansas’s water resources.Real-time data are verified by the USGS throughout the year with regular measurements of streamflow, lake levels, and groundwater levels. These data are used in protecting life and property; and managing water resources for agricultural, industrial, public supply, ecological, and recreational purposes. Yearly hydrologic conditions are characterized by comparing statistical analyses of current and historical water year (WY) data for the period of record. A WY is the 12-month period from October 1 through September 30 and is designated by the year in which it ends.

Comparison of 1972 and 1996 water levels in the Goleta central ground-water subbasin, Santa Barbara County, California

USGS Publications Warehouse

Kaehler, Charles A.; Pratt, David A.; Paybins, Katherine S.

1997-01-01

Ground-water levels for 1996 were compared with 1972 water levels to determine if a "drought buffer" currently exists. The drought buffer was defined previously, in a litigated settlement involving the Goleta Water District, as the 1972 water level in the Central ground-water subbasin. To make this deter mination, a network of 15 well sites was selected, water levels were measured monthly from April through December 1996, and the 1996 water-level data were compared with1972 data. The study was done in cooperation with the Goleta Water District. The 1972-1996 water-level-altitude changes for corresponding months of the comparison years were averaged for each network well. These averaged changes ranged from a rise of 9.4 ft for well 2N2 to a decline of 45.0 ft for well 8K8. The results of the comparison indicate a rise in water level at 1 site (well 2N2) and a decline at 14 sites. The mean of the 14 negative average values was a decline of 24.0 ft. The altitude of the bottom of well 2N2 was higher than the bottom altitudes at the other network sites, and this well is located a few feet from a fault that acts as a hydrologic barrier. The results of the water-level comparison for the Central subbasin were influenced to some unknown degree by the areal distribution of the set of wells selected for the network and the vertical dis tribution of the perforated intervals of the wells. For this reason, the mean water-level change--a decline of 21.8 ft--calculated from the averages of the month-to-month changes for the 15 network sites, should be used with caution. In addition, the number of usable individual monthly comparison measurements available for an individual site ranged from one to nine, and averaged six. Therefore, a weighted mean of the monthly averages was calculated on the basis of the number of comparison measurements available for each site. The weighted mean is a decline of 20.9 ft. All Central subbasin wells that were idle (that is, were not being pumped) when measured in 1972 and that were measureable in 1996 were included in the network. Therefore, the network is the most inclusive possible, given the available data. The objective of the study strictly was to compare 1972 and 1996 water levels in the Central sub basin, and the conclusion is that, overall, 1996 water levels are lower than 1972 levels. In general, hydro graphs for selected network wells indicate stable or rising water levels during 1972-83, declining levels during 1984-92, and rising water levels during 1993-96.

U. S. drinking-water regulations: Treatment technologies and cost

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

Lykins, B.W. Jr.; Clark, R.M.

The Safe Drinking Water Act and its Amendments have imposed a large number of new regulations on the US drinking-water industry. A major set of regulations currently under consideration will control disinfectants and disinfection by-products. Included in the development of these regulations is an Information Collection Rule and an Enhanced Surface Water Treatment Rule. These rules will require monitoring for microorganisms such as Giardia, Cryptosporidium, and viruses. Certain surface-water systems may be required to remove microbiological contaminants above levels currently required by the Surface Water Treatment Rule. Also included in these rules will be monitoring requirements for disinfection by-products andmore » evaluation of precursor removal technologies. As various regulations are promulgated, regulators and those associated with the drinking-water industry need to be cognizant of the potential impact of treatment to control one contaminant or group of contaminants on control of other contaminants. Compliance with drinking-water regulations mandated under the Safe Drinking Water Act and its amendments has been estimated to cost about $1.6 billion.« less

The Water-Energy-Food Nexus in Kazakhstan: Trends and Analyses

NASA Astrophysics Data System (ADS)

Karatayev, Marat; Rivotti, Pedro; Sobral Mourão, Zenaida; Konadu, D. Dennis; Clarke, Michèle

2017-04-01

The concept of the water, energy and food nexus is extremely relevant to Kazakhstan as the country faces population growth, economic progress and environmental challenges such as water scarcity, desertification, and climate change. Furthermore, poor sectoral coordination and institutional fragmentation have caused an unsustainable resource use and threaten the long-term sustainability of water, energy and food security in Kazakhstan. Specifically, low tariffs in the water and electricity sectors have led to under-investment in water and energy efficiency measures, leading to extensive water losses, soil salinity, as well as degradation of agricultural land. Using the nexus approach, this study aims to investigate and map the linkages between water resources, energy production and food security in Kazakhstan, with an emphasis on the current coordination framework. This will enable the identification of critical interdependency issues in the management of these resources. The results will provide a better understanding of the current interconnectedness of the sectors, and support the coordination of decision-making at various levels of governance and research of land, water and energy to meet sustainable development goals.

Modeling wetland plant community response to assess water-level regulation scenarios in the Lake Ontario-St. Lawrence River basin

USGS Publications Warehouse

Hudon, Christiane; Wilcox, Douglas; Ingram, Joel

2006-01-01

The International Joint Commission has recently completed a five-year study (2000-2005) to review the operation of structures controlling the flows and levels of the Lake Ontario - St. Lawrence River system. In addition to addressing the multitude of stakeholder interests, the regulation plan review also considers environmental sustainability and integrity of wetlands and various ecosystem components. The present paper outlines the general approach, scientific methodology and applied management considerations of studies quantifying the relationships between hydrology and wetland plant assemblages (% occurrence, surface area) in Lake Ontario and the Upper and Lower St. Lawrence River. Although similar study designs were used across the study region, different methodologies were required that were specifically adapted to suit the important regional differences between the lake and river systems, range in water-level variations, and confounding factors (geomorphic types, exposure, sediment characteristics, downstream gradient of water quality, origin of water masses in the Lower River). Performance indicators (metrics), such as total area of wetland in meadow marsh vegetation type, that link wetland response to water levels will be used to assess the effects of different regulation plans under current and future (climate change) water-supply scenarios.

Methane release from the southern Brazilian margin during the last glacial.

PubMed

Portilho-Ramos, R C; Cruz, A P S; Barbosa, C F; Rathburn, A E; Mulitza, S; Venancio, I M; Schwenk, T; Rühlemann, C; Vidal, L; Chiessi, C M; Silveira, C S

2018-04-13

Seafloor methane release can significantly affect the global carbon cycle and climate. Appreciable quantities of methane are stored in continental margin sediments as shallow gas and hydrate deposits, and changes in pressure, temperature and/or bottom-currents can liberate significant amounts of this greenhouse gas. Understanding the spatial and temporal dynamics of marine methane deposits and their relationships to environmental change are critical for assessing past and future carbon cycle and climate change. Here we present foraminiferal stable carbon isotope and sediment mineralogy records suggesting for the first time that seafloor methane release occurred along the southern Brazilian margin during the last glacial period (40-20 cal ka BP). Our results show that shallow gas deposits on the southern Brazilian margin responded to glacial-interglacial paleoceanographic changes releasing methane due to the synergy of sea level lowstand, warmer bottom waters and vigorous bottom currents during the last glacial period. High sea level during the Holocene resulted in an upslope shift of the Brazil Current, cooling the bottom waters and reducing bottom current strength, reducing methane emissions from the southern Brazilian margin.

Water resources of the Tulalip Indian Reservation and adjacent area, Snohomish County, Washington, 2001-03

USGS Publications Warehouse

Frans, Lonna M.; Kresch, David L.

2004-01-01

This study was undertaken to improve the understanding of water resources of the Tulalip Plateau area, with a primary emphasis on the Tulalip Indian Reservation, in order to address concerns of the Tulalip Tribes about the effects of current and future development, both on and off the Reservation, on their water resources. The drinking-water supply for the Reservation comes almost entirely from ground water, so increasing population will continue to put more pressure on this resource. The study evaluated the current state of ground- and surface-water resources and comparing results with those of studies in the 1970s and 1980s. The study included updating descriptions of the hydrologic framework and ground-water system, determining if discharge and base flow in streams and lake stage have changed significantly since the 1970s, and preparing new estimates of the water budget. The hydrogeologic framework was described using data collected from 255 wells, including their location and lithology. Data collected for the Reservation water budget included continuous and periodic streamflow measurements, micrometeorological data including daily precipitation, temperature, and solar radiation, water-use data, and atmospheric chloride deposition collected under both wet- and dry-deposition conditions to estimate ground-water recharge. The Tulalip Plateau is composed of unconsolidated sediments of Quaternary age that are mostly of glacial origin. There are three aquifers and two confining units as well as two smaller units that are only localized in extent. The Vashon recessional outwash (Qvr) is the smallest of the three aquifers and lies in the Marysville Trough on the eastern part of the study area. The primary aquifer in terms of use is the Vashon advance outwash (Qva). The Vashon till (Qvt) and the transitional beds (Qtb) act as confining units. The Vashon till overlies Qva and the transitional beds underlie Qva and separate it from the undifferentiated sediments (Qu), which are also a principal aquifer of the plateau. The undifferentiated-sediments aquifer is present throughout the entire study area, but is not well defined because few wells penetrate it. Ground water flows radially outward from the center of the Plateau in the Vashon advance outwash aquifer. Water levels fluctuate seasonally in all hydrogeologic units in response to changes in precipitation over the course of the year. However, water levels do not appear to have changed significantly over the long term. There was no statistically significant change between water levels measured in 72 wells in the early 1990s and 2001. Additionally, when a rank sum test was used to compare monthly water levels measured in 18 wells for this study with monthly water levels from the 1970s and 1980s, water levels increased in some wells, decreased in some, and did not change significantly in others. Ground water in the study area is recharged from precipitation that percolates down from the land surface. Average annual recharge, estimated using the chloride-mass-balance method, was 10.4 inches per year. Current streamflow conditions on the Reservation were defined by four continuous-record streamflow-gaging stations operated from April 2001 through March 2003 and monthly measurements of discharge at 12 periodic-measurement sites. Two continuous-record gaging stations (12157250 and 12158040) near the mouths of Mission and Tulalip Creeks, respectively, also were operated during water years 1975-77. Correlations of streamflow for Mission and Tulalip Creeks with the long-term record of streamflow at Mercer Creek (station 12120000) indicate no significant change in streamflow between the mid-1970s and 2001?03 in Mission and Tulalip Creeks. However, comparisons between the percentage of change in precipitation at the Everett precipitation station and percentages of change in streamflow at the Mercer, Mission, and Tulalip Creek gaging stations from the mid-1970s through 2001

Effects of Aquifer Development and Changes in Irrigation Practices on Ground-Water Availability in the Santa Isabel Area, Puerto Rico

USGS Publications Warehouse

Kuniansky, Eve L.; Gómez-Gómez, Fernando; Torres-Gonzalez, Sigfredo

2003-01-01

The alluvial aquifer in the area of Santa Isabel is located within the South Coastal Plain aquifer of Puerto Rico. Variations in precipitation, changes in irrigation practices, and increasing public-supply water demand have been the primary factors controlling water-level fluctuations within the aquifer. Until the late 1970s, much of the land in the study area was irrigated using inefficient furrow flooding methods that required large volumes of both surface and ground water. A gradual shift in irrigation practices from furrow systems to more efficient micro-drip irrigation systems occurred between the late 1970s and the late 1980s. Irrigation return flow from the furrow-irrigation systems was a major component of recharge to the aquifer. By the early 1990s, furrow-type systems had been replaced by the micro-drip irrigation systems. Water levels declined about 20 feet in the aquifer from 1985 until present (February 2003). The main effect of the changes in agricultural practices is the reduction in recharge to the aquifer and total irrigation withdrawals. Increases in ground-water withdrawals for public supply offset the reduction in ground-water withdrawals for irrigation such that the total estimated pumping rate in 2003 was only 8 percent less than in 1987. Micro-drip irrigation resulted in the loss of irrigation return flow to the aquifer. These changes resulted in lowering the water table below sea level over most of the Santa Isabel area. By 2002, lowering of the water table reversed the natural discharge along the coast and resulted in the inland movement of seawater, which may result in increased salinity of the aquifer, as had occurred in other parts of the South Coastal Plain. Management alternatives for the South Coastal Plain aquifer in the vicinity of Santa Isabel include limiting groundwater withdrawals or implementing artificial recharge measures. Another alternative for the prevention of saltwater intrusion is to inject freshwater or treated sewage effluent into wells along the coast. A digital ground-water flow model was developed to provide information for water managers to evaluate some of these alternatives. After calibration of the ground-water model to historical data, four simulations of ground-water management strategies were performed: ground-water conservation, surface infiltration over existing agricultural fields, or infiltration along streams and canals, or injection wells along the coast. Simulations of four alternative water management strategies indicate that current condition of water levels below sea level near the coast can be reversed to raise water levels above sea level by either: (1) about a 27 percent reduction in 2003 ground-water withdrawal rates; (2) application of about 1,700 million gallons per year of artificial recharge over more than half of the current agricultural areas; (3) injection of about 3 million gallons per day (1,095 million gallons per year) of freshwater or treated wastewater in wells distributed along the coast; (4) injection of about 3.5 million gallons per day (1,280 million gallons per year) of freshwater or treated wastewater in wells distributed along canals and streams.

A SMALL FISH MULTI-ENDPOINT BIOASSAY FOR ASSESSING THE EFFECTS OF WATER CONTAMINANTS PRESENT IN LOW CONCENTRATIONS: MEDAKA AND DICHLOROACETIC ACID

EPA Science Inventory

In regulating the safety of water under SDWA and the CWA, the EPA makes decisions on what chemical contaminants to regulate and at what levels. To make these decisions the EPA needs hazard identification and dose-response information. Current methods that rely on rodent models fo...

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2010

USGS Publications Warehouse

Beman, Joseph E.

2011-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25-40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the basin human population from 1990 to 2000 and about a 22 percent increase from 2000 to 2010 also resulted in an increased demand for water. A network of wells was established by the U.S. Geological Survey in cooperation with the City of Albuquerque to monitor changes in groundwater levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2010), the network consists of 124 wells and piezometers (a piezometer is a small-diameter subwell usually nested within a larger well). To better help the Albuquerque Bernalillo County Water Utility Authority manage water use, this report presents water-level data collected by U.S. Geological Survey personnel at those 124 sites through water year 2010.

Estimating the risk of bladder and kidney cancer from exposure to low-levels of arsenic in drinking water, Nova Scotia, Canada.

PubMed

Saint-Jacques, Nathalie; Brown, Patrick; Nauta, Laura; Boxall, James; Parker, Louise; Dummer, Trevor J B

2018-01-01

Arsenic in drinking water impacts health. Highest levels of arsenic have been historically observed in Taiwan and Bangladesh but the contaminant has been affecting the health of people globally. Strong associations have been confirmed between exposure to high-levels of arsenic in drinking water and a wide range of diseases, including cancer. However, at lower levels of exposure, especially near the current World Health Organization regulatory limit (10μg/L), this association is inconsistent as the effects are mostly extrapolated from high exposure studies. This ecological study used Bayesian inference to model the relative risk of bladder and kidney cancer at these lower concentrations-0-2μg/L; 2-5μg/L and; ≥5μg/L of arsenic-in 864 bladder and 525 kidney cancers diagnosed in the study area, Nova Scotia, Canada between 1998 and 2010. The model included proxy measures of lifestyle (e.g. smoking) and accounted for spatial dependencies. Overall, bladder cancer risk was 16% (2-5μg/L) and 18% (≥5μg/L) greater than that of the referent group (<2μg/L), with posterior probabilities of 88% and 93% for these risks being above 1. Effect sizes for kidney cancer were 5% (2-5μg/L) and 14% (≥5μg/L) above that of the referent group (<2μg/L), with probabilities of 61% and 84%. High-risk areas were common in southwestern areas, where higher arsenic-levels are associated with the local geology. The study suggests an increased bladder cancer, and potentially kidney cancer, risk from exposure to drinking water arsenic-levels within the current the World Health Organization maximum acceptable concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of the Water Levels and Currents at the Mississippi Bight During Hurricane Katrina.

NASA Astrophysics Data System (ADS)

Nwankwo, U. C.; Howden, S. D.; Dodd, D.; Wells, D. E.

2017-12-01

In an effort to extend the length of GPS baselines further offshore, the Hydrographic Science Research Center at the University of Southern Mississippi deployed a buoy which had a survey grade GPS receiver, an ADPC and a motion sensor unit in the Mississippi Bight in late 2004. The GPS data were initially processed using the Post Processed Kinematic technique with data from a nearby GPS base station on Horn Island. This processing technique discontinued when the storm (Hurricane Katrina) destroyed the base station in late August of 2005. However, since then a stand-alone positioning technique termed Precise Point Positioning (PPP) matured and allowed for the reprocessing of the buoy GPS data throughout Katrina. The processed GPS data were corrected for buoy angular motions using Tait Bryan transformation model. Tidal datums (Epoch 1983-2001) were transferred from the National Oceanic and Atmospheric Administration (NOAA) National Water Level at Waveland, Mississippi (Station ID 8747766) to the buoy using the Modified Range Ratio method. The maximum water level during the storm was found to be about 3.578m, relative to the transferred Mean Sea Level datum. The storm surge built over more than 24 hours, but fell back to normal levels in less than 3 hours. The maximum speed of the current with respect to the seafloor was recorded to be about 4knots towards the southeast as the storm surge moved back offshore.

78 FR 19217 - Endangered Species; File No. 16547-01

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-29

... below 22 parts per thousand salinity. Researchers are currently authorized to capture adult, juvenile... telemetry tags dependent on the life stage (adult, sub-adult and juvenile) and the salinity level where... salinity level in the waters of Virginia and Maryland. All previous activities are authorized; however, the...

Hydrostatic Water Level Systems At Homestake DUSEL

NASA Astrophysics Data System (ADS)

Stetler, L. D.; Volk, J. T.

2009-12-01

Two arrays of Fermilab-style hydrostatic water level sensors have been installed in the former Homestake gold mine in Lead, SD, the site of the new Deep Underground Science and Engineering Laboratory (DUSEL). Sensors were constructed at Fermilab from 8.5 cm diameter PVC pipe (housing) that was sealed on the ends and fit with a proximity sensor. The instrument have a height of 10 cm. Two ports in each sensor housing provide for connectivity, the upper port for air and the bottom port for water. Multiple instruments connected in series provide a precise water level and differences in readings between successive sensors provide for ground tilt to be resolved. Sensor resolution is 5 μm per count and has a range of approximately 1.25 cm. Data output from each sensor is relayed to a Fermilab-constructed readout card that also has temperature/relative humidity and barometric pressure sensors connected. All data are relayed out of the mine by fiber optic cable and can be recorded by Ethernet at remote locations. The current arrays have been installed on the 2000-ft level (610 m) and consist of six instruments in each array. Three sensors were placed in a N-S oriented drift and three in an E-W oriented drift. Using this orientation, it is anticipated that tilt direction may be resolved in addition to overall tilt magnitude. To date the data show passage of earth tides and frequency analysis has revealed five components to this signal, three associated with the semi-diurnal (~12.4 hr) and two with the diurnal (~24.9 hr) tides. Currently, installation methods are being analyzed between concrete pillar and rib-mounting using the existing setup on the 2000-ft level. Using these results, two additional arrays of Fermilab instruments will be installed on the 4550-ft and 4850-ft levels (1387 and 1478 m, respectively). In addition to Fermilab instruments, several high resolution Budker tiltmeters (1 μm resolution) will be installed in the mine workings in the near future, some correlated to Fermilab instruments (for comparative analysis) and others in independent arrays. All tiltmeter data will be analyzed with water reduction data (currently being collected from the #6 winze as the mine is dewatered) and data from rock stress/fracture experiments to document net ground settling due to dewatering, potential collapse of stope areas and renewed excavation activities.

A simple and rapid method for monitoring dissolved oxygen in water with a submersible microbial fuel cell (SBMFC).

PubMed

Zhang, Yifeng; Angelidaki, Irini

2012-01-01

A submersible microbial fuel cell (SBMFC) was developed as a biosensor for in situ and real time monitoring of dissolved oxygen (DO) in environmental waters. Domestic wastewater was utilized as a sole fuel for powering the sensor. The sensor performance was firstly examined with tap water at varying DO levels. With an external resistance of 1000Ω, the current density produced by the sensor (5.6 ± 0.5-462.2 ± 0.5 mA/m(2)) increased linearly with DO level up to 8.8 ± 0.3mg/L (regression coefficient, R(2)=0.9912), while the maximum response time for each measurement was less than 4 min. The current density showed different response to DO levels when different external resistances were applied, but a linear relationship was always observed. Investigation of the sensor performance at different substrate concentrations indicates that the organic matter contained in the domestic wastewater was sufficient to power the sensing activities. The sensor ability was further explored under different environmental conditions (e.g. pH, temperature, conductivity, and alternative electron acceptor), and the results indicated that a calibration would be required before field application. Lastly, the sensor was tested with different environmental waters and the results showed no significant difference (p>0.05) with that measured by DO meter. The simple, compact SBMFC sensor showed promising potential for direct, inexpensive and rapid DO monitoring in various environmental waters. Copyright © 2012 Elsevier B.V. All rights reserved.

Broken Chains: The Effect of Ocean Acidification on Bivalve and Echinoid Development

NASA Astrophysics Data System (ADS)

Richardson, K.

2016-12-01

Global warming is one of the most urgent issues facing the interconnected systems of our planet. One important impact of global warming is ocean acidification, which is a change in the pH of the oceans due to increased levels of carbon dioxide in the atmosphere. This can harm ocean life in many ways, including the disintegration of reef structures and the weakening of many types of sea animals' shells. The purpose of this project is to assess the efficacy of a novel method of raising the pH of increasingly acidic ocean waters. The experiment was set up with water of varying pH levels. There were three different experiment groups, including current ocean water (pH 8.1), increased acidity ocean water (pH 7.5), and an increased acidity ocean water with an activated carbon filter (pH 7.5). Six bivalve shells were placed in each solution . Mass loss data was taken from bivalve shells every three days over the course of thirty days (for a total of ten measurements). I hypothesized that the carbon filter would improve the pH of the ocean water (by raising the pH from 7.5) to that of normal ocean water (pH 8.1). The data showed that while the acidic ocean water shell's weight decreased (by 13%), the acidic water with the filter and current ocean water decreased by 0.3% and 0.5%, respectively. Overall, the activated carbon filter decreased the amount of weight change from the acidic water. The data is applicable to helping solve ocean acidification - activated charcoal greatly improved the effects of very acidic ocean water, which could be used in the future to help offset the impact of ocean acidification on its creatures.

Evaluation of automated urban surface water extraction from Sentinel-2A imagery using different water indices

NASA Astrophysics Data System (ADS)

Yang, Xiucheng; Chen, Li

2017-04-01

Urban surface water is characterized by complex surface continents and small size of water bodies, and the mapping of urban surface water is currently a challenging task. The moderate-resolution remote sensing satellites provide effective ways of monitoring surface water. This study conducts an exploratory evaluation on the performance of the newly available Sentinel-2A multispectral instrument (MSI) imagery for detecting urban surface water. An automatic framework that integrates pixel-level threshold adjustment and object-oriented segmentation is proposed. Based on the automated workflow, different combinations of visible, near infrared, and short-wave infrared bands in Sentinel-2 image via different water indices are first compared. Results show that object-level modified normalized difference water index (MNDWI with band 11) and automated water extraction index are feasible in urban surface water mapping for Sentinel-2 MSI imagery. Moreover, comparative results are obtained utilizing optimal MNDWI from Sentinel-2 and Landsat 8 images, respectively. Consequently, Sentinel-2 MSI achieves the kappa coefficient of 0.92, compared with that of 0.83 from Landsat 8 operational land imager.

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2009

USGS Publications Warehouse

Beman, Joseph E.; Torres, Leeanna T.

2010-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the population from 1990 to 2000 also resulted in an increased demand for water. A network of wells was established to monitor changes in groundwater levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2009), the network consists of 131 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 123 sites through water year 2009. In addition, data from four wells (Sites 140, 147, 148, and 149) owned, maintained, and measured by Sandia National Laboratories and three from Kirtland Air Force Base (Sites 119, 125, and 126) are presented in this report.

Regression models of monthly water-level change in and near the Closed Basin Division of the San Luis Valley, south-central Colorado

USGS Publications Warehouse

Watts, Kenneth R.

1995-01-01

The Bureau of Reclamation is developing a water-resource project, the Closed Basin Division, in the San Luis Valley of south-central Colorado that is designed to salvage unconfined ground water that currently is discharged as evapotranspiration. The water table in and near the 130,000-acre Closed Basin Division area will be lowered by an annual withdrawal of as much as 100,000 acre-feet of ground water from the unconfined aquifer. The legislation authorizing the project limits resulting drawdown of the water table in preexisting irrigation and domestic wells outside the Closed Basin Division to a maximum of 2 feet. Water levels in the closed basin in the northern part of the San Luis Valley historically have fluctuated more than 2 feet in response to water-use practices and variation of climatically controlled recharge and discharge. Declines of water levels in nearby wells that are caused by withdrawals in the Closed Basin Division can be quantified if water-level fluctuations that result from other water-use practices and climatic variations can be estimated. This study was done to evaluate water-level change at selected observation wells in and near the Closed Basin Division. Regression models of monthly water-level change were developed to predict monthly water-level change in 46 selected observation wells. Predictions of monthly water-level change are based on one or more of the following: elapsed time, cosine and sine functions with an annual period, streamflow depletion of the Rio Grande, electrical use for agricultural purposes, runoff into the closed basin, precipitation, and mean air temperature. Regression models for five of the wells include only an intercept term and either an elapsed-time term or terms determined by the cosine and sine functions. Regression models for the other 41 wells include 1 to 4 of the 5 other variables, which can vary from month to month and from year to year. Serial correlation of the residuals was detected in 24 of the regression models. These models also include an autoregressive term to account for serial correlation in the residuals. The adjusted coefficient of determination (Ra2) for the 46 regression models range from 0.08 to 0.89, and the standard errors of estimate range from 0.034 to 2.483 feet. The regression models of monthly water- level change can be used to evaluate whether post-1985 monthly water-level change values at the selected observation wells are within the 95-percent confidence limits of predicted monthly water-level change.

Contingency plan to provide safe drinking water for the city of Milan, Tennessee

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

Talbot, J.J.; Brew, P.

1994-12-31

The city of Milan, in western Tennessee, supplies drinking water to approximately 4,000 customers. Environmental investigations conducted by the US Army have detected low concentrations of RDX, a compound used in the manufacture of explosives, in two of the three city water supply wells. The RDX is traceable to the Milan Army Ammunition Plant nearby. The levels of RDX are being monitored and current trends indicate that levels in the wells will exceed the EPA Health Advisory Limits in the near term. In order to ensure an uninterrupted supply of acceptable quality drinking water for the city residents, the Armymore » prepared and is implementing a Contingency Plan. The plan evaluated remedial alternatives to be implemented once a trigger level of RDX is reached, including institutional controls, installation of an RDX treatment system for the water supply system, and construction of a new well field. Institutional controls include: shutting down existing wells; continued monitoring; and promulgation of ground water ordinances. Treatment technologies evaluated include: ultraviolet light and hydrogen peroxide; or removal using granular activated carbon.« less

Flood-inundation maps for the White River at Newberry, Indiana

USGS Publications Warehouse

Fowler, Kathleen K.; Kim, Moon H.; Menke, Chad D.

2012-01-01

Digital flood-inundation maps for a 4.9-mile reach of the White River at Newberry, Indiana (Ind.), were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation, depict estimates of the areal extent of flooding corresponding to selected water levels (stages) at USGS streamgage 03360500, White River at Newberry, Ind. Current conditions at the USGS streamgage may be obtained on the Internet (http://waterdata.usgs.gov/in/nwis/uv?site_no=03360500). The National Weather Service (NWS) forecasts flood hydrographs at the Newberry streamgage. That forecasted peak-stage information, also available on the Internet, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. For this study, flood profiles were computed for the White River reach by means of a one-dimensional step-backwater model developed by the U.S. Army Corps of Engineers. The hydraulic model was calibrated by using the most current stage-discharge relation at USGS streamgage 03360500, White River at Newberry, Ind., and high-water marks from a flood in June 2008.The calibrated hydraulic model was then used to determine 22 water-surface profiles for flood stages a1-foot intervals referenced to the streamgage datum and ranging from bankfull to approximately the highest recorded water level at the streamgage. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from Light Detection and Ranging (LiDAR) data) in order to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage at Newberry, Ind., and forecasted stream stages from the NWS, provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post-flood recovery efforts.

Simulation of Groundwater-Level and Salinity Changes in the Eastern Shore, Virginia

USGS Publications Warehouse

Sanford, Ward E.; Pope, Jason P.; Nelms, David L.

2009-01-01

Groundwater-level and salinity changes have been simulated with a groundwater model developed and calibrated for the Eastern Shore of Virginia. The Eastern Shore is the southern part of the Delmarva Peninsula that is occupied by Accomack and Northampton Counties in Virginia. Groundwater is the sole source of freshwater to the Eastern Shore, and demands for water have been increasing from domestic, industrial, agricultural, and public-supply sectors of the economy. Thus, it is important that the groundwater supply be protected from overextraction and seawater intrusion. The best way for water managers to use all of the information available is usually to compile this information into a numerical model that can simulate the response of the system to current and future stresses. A detailed description of the geology, hydrogeology, and historical groundwater extractions was compiled and entered into the numerical model. The hydrogeologic framework is composed of a surficial aquifer under unconfined conditions, a set of three aquifers and associated overlying confining units under confined conditions (the upper, middle, and lower Yorktown-Eastover Formation), and an underlying confining unit (the St. Marys Formation). An estimate of the location and depths of two major paleochannels was also included in the framework of the model. Total withdrawals from industrial, commercial, public-supply, and some agricultural wells were compiled from the period 1900 through 2003. Reported pumpage from these sources increased dramatically during the 1960s and 70s, up to currently about 4 million gallons per day. Domestic withdrawals were estimated on the basis of population census districts and were assigned spatially to the model on the assumption that domestic users are located close to roads. A numerical model was created using the U.S. Geological Survey (USGS) code SEAWAT to simulate both water levels and concentrations of chloride (representing salinity). The model was calibrated using 605 predevelopment and transient water-level observations that are associated predominantly with 20 observation nests of wells sited across the study area. Sampling for groundwater chemistry at these sites revealed that chloride has not increased significantly in the last 20 years. Environmental tracers in the samples also indicated that the water in the surficial aquifer is typically years to decades old, whereas water in the confined aquifers is typically centuries to millennia old. The calibration procedure yielded distributions of hydraulic conductivity and storage coefficients of the aquifers and confining units that are based on 21 pilot points, but vary smoothly across the study area. The estimated values are consistent with other measurements of these properties measured previously on cores and during hydraulic tests at various well fields. Simulations performed with the model demonstrated that the calibrated model can reproduce the observed historical water levels fairly well (R2 = 0.93). The chloride concentrations were also simulated, but a match with chloride concentrations was more difficult to achieve (R2 = 0.16) because of the lack of sufficient data and the unknown exact behavior of the entire transition zone in the millennia leading up to the present day. Future pumping scenarios were simulated through 2050, with pumping set to either 2003 rates or total permitted withdrawal rates. Water levels in 2050 are predicted to be lower than current levels by a few feet where stresses are currently heaviest but potentially by tens of feet if total permitted withdrawals are extracted at current low-stressed sites. Simulations of chloride concentrations through 2050 revealed some potential for seawater intrusion in the areas of Cape Charles, Chincoteague, east of the town of Exmore, and east of the town of Accomac, but precise estimates of concentration increases are highly uncertain. Simulation results were also used to estimate that the down

Characterization of water in hydrated Bombyx mori silk fibroin fiber and films by 2H NMR relaxation and 13C solid state NMR.

PubMed

Asakura, Tetsuo; Isobe, Kotaro; Kametani, Shunsuke; Ukpebor, Obehi T; Silverstein, Moshe C; Boutis, Gregory S

2017-03-01

The mechanical properties of Bombyx mori silk fibroin (SF), such as elasticity and tensile strength, change remarkably upon hydration. However, the microscopic interaction with water is not currently well understood on a molecular level. In this work, the dynamics of water molecules interacting with SF was studied by 2 H solution NMR relaxation and exchange measurements. Additionally, the conformations of hydrated [3- 13 C]Ala-, [3- 13 C]Ser-, and [3- 13 C]Tyr-SF fibers and films were investigated by 13 C DD/MAS NMR. Using an inverse Laplace transform algorithm, we were able to identify four distinct components in the relaxation times for water in SF fiber. Namely, A: bulk water outside the fiber, B: water molecules trapped weakly on the surface of the fiber, C: bound water molecules located in the inner surface of the fiber, and D: bound water molecules located in the inner part of the fiber were distinguishable. In addition, four components were also observed for water in the SF film immersed in methanol for 30s, while only two components for the film immersed in methanol for 24h. The effects of hydration on the conformation of Ser and Tyr residues in the site-specific crystalline and non-crystalline domains of 13 C selectively labeled SF, respectively, could be determined independently. Our measurements provide new insight relating the characteristics of water and the hydration structure of silk, which are relevant in light of current interest in the design of novel silk-based biomaterials. The mechanical properties of Bombyx mori silk fibroin (SF) change remarkably upon hydration. However, the microscopic interaction between SF and water is not currently well understood on a molecular level. We were able to identify four distinct components in the relaxation times for water in SF fiber by 2 H solution NMR relaxation and exchange measurements. In addition, the effects of hydration on the conformation of Ser and Tyr residues in the site-specific crystalline and non-crystalline domains of 13 C selectively labeled SF, respectively, could be determined independently. Thus, our measurements provide new insight relating the characteristics of water and the hydration structure of silk, which are relevant in light of current interest in the design of novel silk-based biomaterials. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Flood-inundation maps for the Mississinewa River at Marion, Indiana, 2013

USGS Publications Warehouse

Coon, William F.

2014-01-01

Digital flood-inundation maps for a 9-mile (mi) reach of the Mississinewa River from 0.75 mi upstream from the Pennsylvania Street bridge in Marion, Indiana, to 0.2 mi downstream from State Route 15 were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The flood inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Mississinewa River at Marion (station number 03326500). Near-real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service at http://water.weather.gov/ahps/, which also forecasts flood hydrographs at this site. Flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the current stage-discharge relation at the Mississinewa River streamgage, in combination with water-surface profiles from historic floods and from the current (2002) flood-insurance study for Grant County, Indiana. The hydraulic model was then used to compute seven water-surface profiles for flood stages at 1-fo (ft) intervals referenced to the streamgage datum and ranging from 10 ft, which is near bankfull, to 16 ft, which is between the water levels associated with the estimated 10- and 2-percent annual exceedance probability floods (floods with recurrence interval between 10 and 50 years) and equals the “major flood stage” as defined by the NWS. The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from light detection and ranging (lidar) data having a 0.98 ft vertical accuracy and 4.9 ft horizontal resolution) to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage and forecasted high-flow stages from the NWS, will provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

Ground Water in the Anchorage Area, Alaska--Meeting the Challenges of Ground-Water Sustainability

USGS Publications Warehouse

Moran, Edward H.; Galloway, Devin L.

2006-01-01

Ground water is an important component of Anchorage's water supply. During the 1970s and early 80s when ground water extracted from aquifers near Ship Creek was the principal source of supply, area-wide declines in ground-water levels resulted in near record low streamflows in Ship Creek. Since the importation of Eklutna Lake water in the late 1980s, ground-water use has been reduced and ground water has contributed 14-30 percent of the annual supply. As Anchorage grows, given the current constraints on the Eklutna Lake water availability, the increasing demand for water could place an increasing reliance on local ground-water resources. The sustainability of Anchorage's ground-water resources challenges stakeholders to develop a comprehensive water-resources management strategy.

Hydrogeology and simulation of regional ground-water-level declines in Monroe County, Michigan

USGS Publications Warehouse

Reeves, Howard W.; Wright, Kirsten V.; Nicholas, J.R.

2004-01-01

Observed ground-water-level declines from 1991 to 2003 in northern Monroe County, Michigan, are consistent with increased ground-water demands in the region. In 1991, the estimated ground-water use in the county was 20 million gallons per day, and 80 percent of this total was from quarry dewatering. In 2001, the estimated ground-water use in the county was 30 million gallons per day, and 75 percent of this total was from quarry dewatering. Prior to approximately 1990, the ground-water demands were met by capturing natural discharge from the area and by inducing leakage through glacial deposits that cover the bedrock aquifer. Increased ground-water demand after 1990 led to declines in ground-water level as the system moves toward a new steady-state. Much of the available natural discharge from the bedrock aquifer had been captured by the 1991 conditions, and the response to additional withdrawals resulted in the observed widespread decline in water levels. The causes of the observed declines were explored through the use of a regional ground-water-flow model. The model area includes portions of Lenawee, Monroe, Washtenaw, and Wayne Counties in Michigan, and portions of Fulton, Henry, and Lucas Counties in Ohio. Factors, including lowered water-table elevations because of below average precipitation during the time period (1991 - 2001) and reduction in water supply to the bedrock aquifer because of land-use changes, were found to affect the regional system, but these factors did not explain the regional decline. Potential ground-water capture for the bedrock aquifer in Monroe County is limited by the low hydraulic conductivity of the overlying glacial deposits and shales and the presence of dense saline water within the bedrock as it dips into the Michigan Basin to the west and north of the county. Hydrogeologic features of the bedrock and the overlying glacial deposits were included in the model design. An important step of characterizing the bedrock aquifer was the determination of inputs and outputs of water—leakage from glacial deposits and flows across model boundaries. The imposed demands on the groundwater system create additional discharge from the bedrock aquifer, and this discharge is documented by records and estimates of water use including: residential and industrial use, irrigation, and quarry dewatering. Hydrologic characterization of Monroe County and surrounding areas was used to determine the model boundaries and inputs within the ground-water model. MODFLOW-2000 was the computer model used to simulate ground-water flow. Predevelopment, 1991, and 2001 conditions were simulated with the model. The predevelopment model did not include modern water use and was compared to information from early settlement of the county. The 1991 steady-state model included modern demands on the ground-water system and was based on a significant amount of data collected for this and previous studies. The predevelopment and 1991 simulations were used to calibrate the numerical model. The simulation of 2001 conditions was based on recent data and explored the potential ground-water levels if the current conditions persist. Model results indicate that the ground-water level will stabilize in the county near current levels if the demands imposed during 2001 are held constant.

Use of short-term toxicity data for prediction of long-term health effects

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

Hartley, W.R.; Ohanian, E.V.

1988-01-01

Under the Safe Drinking Water Act Amendments of 1986, the US Environmental Protection Agency determines Maximum Contaminant Level Goals (MCLGs) and enforceable Maximum Contaminant Levels (MCLs) or provides lifetime health advisories (HAs) in the absence of regulatory standards. The critical value for calculation of the lifetime level is the reference dose (RfD). The RfD is an estimate of a lifetime dose which is likely to be without significant risk to human populations. The RfD is determined by dividing the no-observed-adverse-effect level (NOAEL) or the lowest-observed-adverse-effect level (LOAEL) by an uncertainty factor (UF). The NOAEL or LOAEL is determined from toxicologicalmore » or epidemiological studies. For many chemicals, human toxicological or epidemiological data are not available. Chronic mammalian studies are sometimes unavailable. Faced with the need for providing guidance for the increasing number of chemicals threatening our drinking water sources, this paper considers the possibility of providing provisional RfDs using data from toxicological studies of less than ninety days duration. The current UF approach is reviewed along with some proposed mathematical models for extrapolation of NOAELs from dose-response data. The current UF approach to developing the RfD is protective and conservative. More research is needed on the relationship of short- and long-term toxicity data to improve our current approach.« less

Chemical composition of natural waters of contaminated area: The case for the Imandra Lake catchment (the Kola Peninsula)

NASA Astrophysics Data System (ADS)

Evtyugina, Z. A.; Guseva, N. V.; Kopylova, J. G.; A, Vorobeva D.

2016-03-01

The study of the current chemical composition of natural waters in the eastern and western parts of the Imandra Lake catchment was performed using ion chromatography, potentiometry and inductively coupled plasma mass spectrometry. It was found that the content of trace elements in the surface water is considerably higher than that in the groundwater. The nickel and copper concentrations exceed the background levels over 19 and 2 times respectively in groundwater, and 175 and 61 times in the surface waters. These data show that the Severonikel influences negatively air and surface water.

LLWBCS changes through surface mesoscale activity and baroclinic tides in the Solomon Sea

NASA Astrophysics Data System (ADS)

Gourdeau, L.; Djath, B.; Ganachaud, A. S.; Tchilibou, M. L.; Verron, J. A.; Jouanno, J.

2016-02-01

In the south west Pacific, the Solomon Sea is on the pathway of the Low Latitudes Western Boundary Currents that connect the subtropics to the equator. Changes in their strengths, or in their water mass properties may have implication for ENSO and its low frequency modulation. During their transit in the Solomon Sea, the salinity maximum at thermocline level, characteristic of the South Pacific Tropical Waters (SPTW), is largely eroded. Different mechanisms could explain such salt erosion whose current/bathymetry interaction, internal tides, eddy activity. The Solomon Sea is an area of high level of eddy kinetic energy (EKE), especially in the surface layers, and its complex bathymetry is favourable for generation and dissipation of internal tides. Based on high resolution modelling, glider, and altimetric data mesoscale eddies observed at the surface are analysed in their 4D aspects. Their role on water mass transformation is explored. These eddies may affect the surface layers (σ<23.3) and the upper thermocline waters (23.3< σ <24.3), but they cannot explained the erosion of the salinity maximum below. Simulations with and without explicit tides provide a description of baroclinic tides in the Solomon Sea. Their role on water mixing is evaluated, especially for the SPTW.

A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa.

PubMed

van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L

2008-12-01

This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.

Inactivation of Pathogenic Microorganisms in Infectious Medical Waste. A Literature Review of Current On-Site Treatment Technologies.

DTIC Science & Technology

1992-01-01

by thermal inactivation, removal in soil, and dilution in ground and surface waters . 0 18 Chapter II: Treatment Technologies Kinetics of Thermal...reaction with water in which the proteins coagulate or precipitate. This is analogous to heat transforming the raw egg medium into a rigid egg white...to either allow germination and outgrowth after adsorption and diffusion of nutrients and water , or penetration of high energy levels of heat which

Advanced space power PEM fuel cell systems

NASA Technical Reports Server (NTRS)

Vanderborgh, N. E.; Hedstrom, J.; Huff, J. R.

1989-01-01

A model showing mass and heat transfer in proton exchange membrane (PEM) single cells is presented. For space applications, stack operation requiring combined water and thermal management is needed. Advanced hardware designs able to combine these two techniques are available. Test results are shown for membrane materials which can operate with sufficiently fast diffusive water transport to sustain current densities of 300 ma per square centimeter. Higher power density levels are predicted to require active water removal.

Numerical Analysis of the Effect of Active Wind Speed and Direction on Circulation of Sea of Azov Water with and without Allowance for the Water Exchange through the Kerch Strait

NASA Astrophysics Data System (ADS)

Cherkesov, L. V.; Shul'ga, T. Ya.

2018-01-01

The effect of seawater movement through the Kerch Strait for extreme deviations in the level and speed of currents in the Sea of Azov caused by the action of climate wind fields has been studied using the Princeton ocean model (POM), a general three-dimensional nonlinear model of ocean circulation. Formation of the water flow through the strait is caused by the long-term action of the same type of atmospheric processes. The features of the water dynamics under conditions of changing intensity and active wind direction have been studied. Numerical experiments were carried out for two versions of model Sea of Azov basins: closed (without the Kerch Strait) and with a fluid boundary located in the Black Sea. The simulation results have shown that allowance for the strait leads to a significant change in the velocities of steady currents and level deviations at wind speeds greater than 5 m/s. The most significant effect on the parameters of steady-state movements is exerted by the speed of the wind that generates them; allowance for water exchange through the strait is less important. Analysis of the directions of atmospheric circulation has revealed that the response generated by the movement of water through the strait is most pronounced when a southeast wind is acting.

Supporting inland waterway transport on German waterways by operational forecasting services - water-levels, discharges, river ice

NASA Astrophysics Data System (ADS)

Meißner, Dennis; Klein, Bastian; Ionita, Monica; Hemri, Stephan; Rademacher, Silke

2017-04-01

Inland waterway transport (IWT) is an important commercial sector significantly vulnerable to hydrological impacts. River ice and floods limit the availability of the waterway network and may cause considerable damages to waterway infrastructure. Low flows significantly affect IWT's operation efficiency usually several months a year due to the close correlation of (low) water levels / water depths and (high) transport costs. Therefore "navigation-related" hydrological forecasts focussing on the specific requirements of water-bound transport (relevant forecast locations, target parameters, skill characteristics etc.) play a major role in order to mitigate IWT's vulnerability to hydro-meteorological impacts. In light of continuing transport growth within the European Union, hydrological forecasts for the waterways are essential to stimulate the use of the free capacity IWT still offers more consequently. An overview of the current operational and pre-operational forecasting systems for the German waterways predicting water levels, discharges and river ice thickness on various time-scales will be presented. While short-term (deterministic) forecasts have a long tradition in navigation-related forecasting, (probabilistic) forecasting services offering extended lead-times are not yet well-established and are still subject to current research and development activities (e.g. within the EU-projects EUPORIAS and IMPREX). The focus is on improving technical aspects as well as on exploring adequate ways of disseminating and communicating probabilistic forecast information. For the German stretch of the River Rhine, one of the most frequented inland waterways worldwide, the existing deterministic forecast scheme has been extended by ensemble forecasts combined with statistical post-processing modules applying EMOS (Ensemble Model Output Statistics) and ECC (Ensemble Copula Coupling) in order to generate water level predictions up to 10 days and to estimate its predictive uncertainty properly. Additionally for the key locations at the international waterways Rhine, Elbe and Danube three competing forecast approaches are currently tested in a pre-operational set-up in order to generate monthly to seasonal (up to 3 months) forecasts: (1) the well-known Ensemble Streamflow Prediction approach (ensemble based on historical meteorology), (2) coupling hydrological models with post-processed outputs from ECMWF's general circulation model (System 4), and (3) a purely statistical approach based on the stable relationship (teleconnection) of global or regional oceanic, climate and hydrological data with river flows. The current results, still pre-operational, reveal the existence of a valuable predictability of water levels and streamflow also at monthly up to seasonal time-scales along the larger rivers used as waterways in Germany. Last but not least insight into the technical set-up of the aforementioned forecasting systems operated at the Federal Institute of Hydrology, which are based on a Delft-FEWS application, will be given focussing on the step-wise extension of the former system by integrating new components in order to meet the growing needs of the customers and to improve and extend the forecast portfolio for waterway users.

River Discharge and Bathymetry Estimation from Hydraulic Inversion of Surface Currents and Water Surface Elevation Observations

NASA Astrophysics Data System (ADS)

Simeonov, J.; Holland, K. T.

2015-12-01

We developed an inversion model for river bathymetry and discharge estimation based on measurements of surface currents, water surface elevation and shoreline coordinates. The model uses a simplification of the 2D depth-averaged steady shallow water equations based on a streamline following system of coordinates and assumes spatially uniform bed friction coefficient and eddy viscosity. The spatial resolution of the predicted bathymetry is related to the resolution of the surface currents measurements. The discharge is determined by minimizing the difference between the predicted and the measured streamwise variation of the total head. The inversion model was tested using in situ and remote sensing measurements of the Kootenai River east of Bonners Ferry, ID. The measurements were obtained in August 2010 when the discharge was about 223 m3/s and the maximum river depth was about 6.5 m. Surface currents covering a 10 km reach with 8 m spatial resolution were estimated from airborne infrared video and were converted to depth-averaged currents using acoustic Doppler current profiler (ADCP) measurements along eight cross-stream transects. The streamwise profile of the water surface elevation was measured using real-time kinematic GPS from a drifting platform. The value of the friction coefficient was obtained from forward calibration simulations that minimized the difference between the predicted and measured velocity and water level along the river thalweg. The predicted along/cross-channel water depth variation was compared to the depth measured with a multibeam echo sounder. The rms error between the measured and predicted depth along the thalweg was found to be about 60cm and the estimated discharge was 5% smaller than the discharge measured by the ADCP.

Field assessment of a novel household-based water filtration device: a randomised, placebo-controlled trial in the Democratic Republic of Congo.

PubMed

Boisson, Sophie; Kiyombo, Mbela; Sthreshley, Larry; Tumba, Saturnin; Makambo, Jacques; Clasen, Thomas

2010-09-10

Household water treatment can improve the microbiological quality of drinking water and may prevent diarrheal diseases. However, current methods of treating water at home have certain shortcomings, and there is evidence of bias in the reported health impact of the intervention in open trial designs. We undertook a randomised, double-blinded, placebo-controlled trial among 240 households (1,144 persons) in rural Democratic Republic of Congo to assess the field performance, use and effectiveness of a novel filtration device in preventing diarrhea. Households were followed up monthly for 12 months. Filters and placebos were monitored for longevity and for microbiological performance by comparing thermotolerant coliform (TTC) levels in influent and effluent water samples. Mean longitudinal prevalence of diarrhea was estimated among participants of all ages. Compliance was assessed through self-reported use and presence of water in the top vessel of the device at the time of visit. Over the 12-month follow-up period, data were collected for 11,236 person-weeks of observation (81.8% total possible). After adjusting for clustering within the household, the longitudinal prevalence ratio of diarrhoea was 0.85 (95% confidence interval: 0.61-1.20). The filters achieved a 2.98 log reduction in TTC levels while, for reasons that are unclear, the placebos achieved a 1.05 log reduction (p<0.0001). After 8 months, 68% of intervention households met the study's definition of current users, though most (73% of adults and 95% of children) also reported drinking untreated water the previous day. The filter maintained a constant flow rate over time, though 12.4% of filters were damaged during the course of the study. While the filter was effective in improving water quality, our results provide little evidence that it was protective against diarrhea. The moderate reduction observed nevertheless supports the need for larger studies that measure impact against a neutral placebo. Current Controlled Trials ISRCTN03844341.

Historical and hypothetical future sedimentation and water storage in Kajakai Reservoir, central Afghanistan

USGS Publications Warehouse

Vining, Kevin C.; Vecchia, Aldo V.

2008-01-01

Sedimentation has reduced water storage in Kajakai Reservoir. If current sedimentation rates continue, hypothetical future reservoir water volumes at the spillway elevation of 1,033.5 meters could be reduced about 22 percent from 2006 to 2057. Even if the spillway elevation is raised to 1,045 meters, a severe drought could result in large multiyear irrigation-supply deficits in which reservoir water levels remain below 1,022 meters for more than 4 years. Hypothetical climate change and sedimentation could result in greater water-supply deficits. The chance of having sufficient water supplies in Kajakai Reservoir during the worst month is about 47 percent.

Review of the hydrologic data-collection network in the St Joseph River basin, Indiana

USGS Publications Warehouse

Crompton, E.J.; Peters, J.G.; Miller, R.L.; Stewart, J.A.; Banaszak, K.J.; Shedlock, R.J.

1986-01-01

The St. Joseph River Basin data-collection network in the St. Joseph River for streamflow, lake, ground water, and climatic stations was reviewed. The network review included only the 1700 sq mi part of the basin in Indiana. The streamflow network includes 11 continuous-record gaging stations and one partial-record station. Based on areal distribution, lake effect , contributing drainage area, and flow-record ratio, six of these stations can be used to describe regional hydrology. Gaging stations on lakes are used to collect long-term lake-level data on which to base legal lake levels, and to monitor lake-level fluctuations after legal levels are established. More hydrogeologic data are needed for determining the degree to which grouhd water affects lake levels. The current groundwater network comprises 15 observation wells and has four purposes: (1) to determine the interaction between groundwater and lakes; (2) to measure changes in groundwater levels near irrigation wells; (3) to measure water levels in wells at special purpose sites; and (4) to measure long-term changes in water levels in areas not affected by pumping. Seven wells near three lakes have provided sufficient information for correlating water levels in wells and lakes but are not adequate to quantify the effect of groundwater on lake levels. Water levels in five observation wells located in the vicinity of intensive irrigation are not noticeably affected by seasonal withdrawals. The National Weather Sevice operates eight climatic stations in the basin primarily to characterize regional climatic conditions and to aid in flood forecasting. The network meets network-density guidelines established by the World Meterological Organization for collection of precipitation and evaporation data but not guidelines suggested by the National Weather Service for density of precipitation gages in areas of significant convective rainfalls. (Author 's abstract)

Riders on the storm: selective tidal movements facilitate the spawning migration of threatened delta smelt in the San Francisco Estuary

USGS Publications Warehouse

Bennett, W.A.; Burau, Jon R.

2015-01-01

Migration strategies in estuarine fishes typically include behavioral adaptations for reducing energetic costs and mortality during travel to optimize reproductive success. The influence of tidal currents and water turbidity on individual movement behavior were investigated during the spawning migration of the threatened delta smelt, Hypomesus transpacificus, in the northern San Francisco Estuary, California, USA. Water current velocities and turbidity levels were measured concurrently with delta smelt occurrence at sites in the lower Sacramento River and San Joaquin River as turbidity increased due to first-flush winter rainstorms in January and December 2010. The presence/absence of fish at the shoal-channel interface and near the shoreline was quantified hourly over complete tidal cycles. Delta smelt were caught consistently at the shoal-channel interface during flood tides and near the shoreline during ebb tides in the turbid Sacramento River, but were rare in the clearer San Joaquin River. The apparent selective tidal movements by delta smelt would facilitate either maintaining position or moving upriver on flood tides, and minimizing advection down-estuary on ebb tides. These movements also may reflect responses to lateral gradients in water turbidity created by temporal lags in tidal velocities between the near-shore and mid-channel habitats. This migration strategy can minimize the energy spent swimming against strong river and tidal currents, as well as predation risks by remaining in turbid water. Selection pressure on individuals to remain in turbid water may underlie population-level observations suggesting that turbidity is a key habitat feature and cue initiating the delta smelt spawning migration.

Simulated ground-water flow for a pond-dominated aquifer system near Great Sandy Bottom Pond, Pembroke, Massachusetts

USGS Publications Warehouse

Carlson, Carl S.; Lyford, Forest P.

2005-01-01

A ground-water flow simulation for a 66.4-square-mile area around Great Sandy Bottom (GSB) Pond (105 acres) near Pembroke, Massachusetts, was developed for use by local and State water managers to assess the yields for public water supply of local ponds and wells for average climatic and drought conditions and the effects of water withdrawals on nearby water levels and streamflows. Wetlands and ponds cover about 30 percent of the study area and the aquifer system is dominated by interactions between ground water and the ponds. The three largest surface-water bodies in the study area are Silver Lake (640 acres), Monponsett Pond (590 acres), and Oldham Pond (236 acres). The study area is drained by tributaries of the Taunton River to the southwest, the South and North Rivers to the northeast, and the Jones River to the southeast. In 2002, 10.8 million gallons per day of water was exported from ponds and 3.5 million gallons per day from wells was used locally for public supply. A transient ground-water-flow model with 69 monthly stress periods spanning the period from January 1998 through September 2003 was calibrated to stage at GSB Pond and nearby Silver Lake and streamflow and water levels collected from September 2002 through September 2003. The calibrated model was used to assess hydrologic responses to a variety of water-use and climatic conditions. Simulation of predevelopment (no pumping or export) average monthly (1949-2002) water-level conditions caused the GSB Pond level to increase by 6.3 feet from the results of a simulation using average 2002 pumping for all wells, withdrawals, and exports. Most of this decline can be attributed to pumping, withdrawals, and exports of water from sites away from GSB Pond. The effects of increasing the export rate from GSB Pond by 1.25 and 1.5 times the 2002 rate were a lowering of pond levels by a maximum of 1.6 and 2.8 feet, respectively. Simulated results for two different drought conditions, one mild drought similar to that of 1979-82 and a more severe drought similar to that of 1963-66, but with current (2002) pumping, were compared to results for average monthly recharge conditions (1949-2002). Simulated mild drought conditions showed a reduction of GSB Pond level of about 1.3 feet and a lower streamflow of about 1.7 percent in the nearby stream. Simulated severe drought conditions reduced the pond level at GSB Pond by almost 7 feet and lowered streamflow by about 37 percent. Varying cranberry-irrigation practices had little effect on simulated GSB Pond water levels, but may be important in other ponds. The model was most sensitive to changes in areal recharge. An increase and decrease of 22 percent in recharge produced changes in the GSB Pond water level of +1.4 feet and -2.4 feet, respectively. The accuracy of simulation results was best in the central portion of the study area in the immediate location of GSB Pond. The model was developed with the study-area boundary far enough away from the GSB Pond area that the boundary would have minimal effect on the water levels in GSB Pond, nearby ponds, and the underlying aquifer system. The model is best suited for use by local and State water managers to assess the effects of different withdrawal scenarios for wells and ponds near GSB Pond and for general delineation of areas contributing recharge to wells and ponds in the vicinity of GSB Pond. The model in its current form may not be well suited to detailed analyses of water budgets and flow patterns for parts of the study area farther from GSB Pond without further investigation, calibration, and data collection.

THE EFFECT OF WATER CHEMISTRY AND IRON PARTICLE PROPERTIES ON THE REMOVAL OF ARSENIC FOLLOWING THE OXIDATION OF FERROUS IRON

EPA Science Inventory

The current MCL for arsenic is being revised to a lower level by the USEPA. Many new utilities, particularly small utilities, will be forced to add an arsenic removal process or fine tune their curent water treatment process to meet the new MCL. Many arsenic removal processes rel...

Effect of mesoscale eddies on the Taiwan Strait Current

NASA Astrophysics Data System (ADS)

Chang, Y. L.; Miyazawa, Y.; Guo, X.

2016-02-01

This study shows that mesoscale eddies can alter the Taiwan Strait current. The 20-year data-assimilated Japan Coastal Ocean Predictability Experiment 2 (JCOPE2) reanalysis data are analyzed, and the results are confirmed with idealized experiments. The leading wind-forced seasonal cycle is excluded to focus on the effect of the eddy. The warm eddy southwest of Taiwan is shown to generate a northward flow, whereas the cold eddy produces a southward current. The effect of the eddy penetrates onto the shelf through the Joint Effect of Baroclinicity and Relief (JEBAR). The cross-isobath fluxes lead to shelfward convergence and divergence, setting up the modulation of the sea level slope. The resulting along-strait current anomaly eventually affects a wide area of the Taiwan Strait. The stronger eddy leads to larger modification of the cross-shelf flows and sea level slope, producing a greater transport anomaly. The composite Sea-Viewing Wide Field-of-view Sensor chlorophyll-a (Chl-a) serves as an indicator to show the change in Chl-a concentration in the strait in response to the eddy-induced current. During the warm eddy period, the current carries the southern water of lower concentration northward, reducing Chl-a concentration in the strait. In contrast, Chl-a is enhanced because the cold eddy-induced southward current carries the northern water of higher concentration southward into the strait.

Towards health impact assessment of drinking-water privatization--the example of waterborne carcinogens in North Rhine-Westphalia (Germany).

PubMed Central

Fehr, Rainer; Mekel, Odile; Lacombe, Martin; Wolf, Ulrike

2003-01-01

Worldwide there is a tendency towards deregulation in many policy sectors - this, for example, includes liberalization and privatization of drinking-water management. However, concerns about the negative impacts this might have on human health call for prospective health impact assessment (HIA) on the management of drinking-water. On the basis of an established generic 10-step HIA procedure and on risk assessment methodology, this paper aims to produce quantitative estimates concerning health effects from increased exposure to carcinogens in drinking-water. Using data from North Rhine-Westphalia in Germany, probabilistic estimates of excess lifetime cancer risk, as well as estimates of additional cases of cancer from increased carcinogen exposure levels are presented. The results show how exposure to contaminants that are strictly within current limits could increase cancer risks and case-loads substantially. On the basis of the current analysis, we suggest that with uniform increases in pollutant levels, a single chemical (arsenic) is responsible for a large fraction of expected additional risk. The study also illustrates the uncertainty involved in predicting the health impacts of changes in water quality. Future analysis should include additional carcinogens, non-cancer risks including those due to microbial contamination, and the impacts of system failures and of illegal action, which may be increasingly likely to occur under changed management arrangements. If, in spite of concerns, water is privatized, it is particularly important to provide adequate surveillance of water quality. PMID:12894324

Annual summary of ground-water conditions in Arizona, spring 1979 to spring 1980

USGS Publications Warehouse

,

1981-01-01

Withdrawal of ground water, about 4.0 million acre-feet in Arizona in 1979, is about 200,000 acre-feet less than the amount withdrawn in 1978. The withdrawals in 1978 and 1979 are the smallest since the mid-1950 's except in 1966. Nearly all the decrease was in the amount of ground water used for irrigation in the Basin and Range lowlands province. The large amount of water in storage in the surface-water reservoirs, release of water from the reservoirs, floods, and conservation practices contributed to the decrease in ground-water use and caused water-level rises in the Salt River Valley, Gila Bend basin, and Gila River drainage from Painted Rock Dam to Texas Hill. Two small-scale maps show ground-water pumpage by areas and the status of the ground-water inventory in the State. The main map, which is at a scale of 1:500,000, shows potential well production, depth to water in selected wells in spring 1980, and change in water level in selected wells from 1975 to 1980. A brief text summarizes the current ground-water conditions in the State. (USGS)

Ground-water development and the effects on ground-water levels and water quality in the town of Atherton, San Mateo County, California

USGS Publications Warehouse

Metzger, Loren F.; Fio, John L.

1997-01-01

The installation of at least 100 residential wells in the town of Atherton, California, during the 198792 drought has raised concerns about the increased potential for land subsidence and salt water intrusion. Data were collected and monitor ing networks were established to assess current processes and to monitor future conditions affect ing these processes. Data include recorded pump age, recorded operation time, and measured pumpage rates from 38 wells; water levels from 49 wells; water chemistry samples from 20 wells, and land-surface elevation data from 22 survey sites, including one National Geodetic Survey estab lished bench mark. Geologic, lithologic, climato logic, well construction, well location, and historical information obtained from available reports and local, state, and Federal agencies were used in this assessment. Estimates of annual residential pumpage from 269 assumed active residential wells in the study area indicate that the average annual total pumping rate is between 395 and 570 acre-feet per year. The nine assumed active institutional wells are estimated to pump a total of about 200 acre- feet per year, or 35 to 50 percent of the total resi dential pumpage. Assuming that 510 acre-feet per year is the best estimate of annual residential pumpage, total pumpage of 710 acre-feet per year would represent about 19 percent of the study area's total water supply, as estimated. Depth-to-water-level measurements in wells during April 1993 through September 1995 typically ranged from less than 20 feet below land surface nearest to San Francisco Bay to more than 70 feet below land surface in upslope areas near exposed bedrock, depending on the season. This range, which is relatively high historically, is attributed to above normal rainfall between 1993 and 1995. Water levels expressed as hydraulic heads indicate the presence of three different hydrologic subareas on the basis of hydraulic-head contour configurations and flow direction. That all measured hydraulic heads in the study area from April 1993 through September 1995 were above sea level indicates that saltwater intrusion was unlikely during this period. The chemistry of 20 well-water samples is characterized as a calcium magnesium carbonate bicarbonate type water. There is no evidence of saltwater intrusion from San Francisco Bay; how ever, water samples from wells nearest the bay and bedrock assemblages indicate a greater concentra tion of dissolved constituents and salinity. Dissolved-solids concentrations of water samples from wells in these areas exceeded 1,000 milli grams per liter, and several samples contained a substantial fraction of sodium and chloride. Water hardness for the 20 wells sampled averaged 471 milligrams per liter as calcium carbonate, which is classified as very hard. One well sample exceeded the primary maximum contaminant level for drinking water in nitrate, several wells exceeded the secondary maximum contaminant level for chloride and sulfate, and all wells sampled exceeded the secondary maximum contaminant level for total dissolved solids. Land-subsidence and the resultant damage because of excessive ground-water pumping, in combination with periodic drought, have a well- documented history in the south San Francisco Bay area. Land-elevation surveying data from 1934 to 1967 indicate that subsidence ranged from 0.1 to approximately 0.5 foot in the vicinity of the study area. It could not be determined from land- surface elevation surveying data from 1993 whether subsidence is currently occurring in the study area.

Development of a relative risk model for drinking water regulation and design recommendations for a peri urban region of Argentina.

PubMed

Rodriguez-Alvarez, María Soledad; Weir, Mark H; Pope, Joanna M; Seghezzo, Lucas; Rajal, Verónica B; Salusso, María Mónica; Moraña, Liliana B

2015-10-01

Argentina is a developing Latin American nation that has an aim of achieving the United Nations Millennium Development Goals for potable water supplies. Their current regulations however, limit the continued development of improved potable water quality and infrastructure from a microbiological viewpoint. This is since the current regulations are focused solely to pathogenic Eschericia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and fecal indicators. Regions of lower socioeconomic status such as peri-urban areas are particularly at risk due to lessened financial and political ability to influence their environmental quality and infrastructure needs. Therefore, a combined microbiological sampling, analysis and quantitative microbial risk assessment (QMRA) modeling effort were engaged for a peri-urban area of Salta Argentina. Drinking water samples from home taps were analyzed and a QMRA model was developed, results of which were compared against a general 1:10,000 risk level for lack of a current Argentinian standard. This QMRA model was able to demonstrate that the current regulations were being achieved for E. coli but were less than acceptable for P. aeruginosa in some instances. Appropriate health protections are far from acceptable for Giardia for almost all water sources. Untreated water sources were sampled and analyzed then QMRA modeled as well, since a significant number of the community (∼9%) still use them for potable water supplies. For untreated water E. coli risks were near 1:10,000, however, P. aeruginosa and Giardia risks failed to be acceptable in almost all instances. The QMRA model and microbiological analyses demonstrate the need for improved regulatory efforts for the peri-urban area along with improved investment in their water infrastructure. Copyright © 2015 Elsevier GmbH. All rights reserved.

Flood-inundation maps for the Iroquois River at Rensselaer, Indiana

USGS Publications Warehouse

Fowler, Kathleen K.; Bunch, Aubrey R.

2013-01-01

Digital flood-inundation maps for a 4.0-mile reach of the Iroquois River at Rensselaer, Indiana (Ind.), were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at USGS streamgage 05522500, Iroquois River at Rensselaer, Ind. Current conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the Internet at (http://waterdata.usgs.gov/in/nwis/uv?site_no=05522500). In addition, the National Weather Service (NWS) forecasts flood hydrographs at the Rensselaer streamgage. That forecasted peak-stage information, also available on the Internet (http://water.weather.gov/ahps/), may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. For this study, flood profiles were computed for the Iroquois River reach by means of a one-dimensional step-backwater model developed by the U.S. Army Corps of Engineers. The hydraulic model was calibrated by using the most current (June 27, 2012) stage-discharge relations at USGS streamgage 05522500, Iroquois River at Rensselaer, Ind., and high-water marks from the flood of July 2003. The calibrated hydraulic model was then used to determine nine water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the highest stage of the current stage-discharge rating curve. The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from Light Detection and Ranging (LiDAR) data) in order to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage at Rensselaer, Ind., and forecasted stream stages from the NWS, provides emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

Ground-water flow and quality in the Atlantic City 800-foot sand, New Jersey

USGS Publications Warehouse

McAuley, Steven D.; Barringer, Julia L.; Paulachok, Gary N.; Clark, Jeffrey S.; Zapecza, Otto S.

2001-01-01

The regional, confined Atlantic City 800-foot sand is the principal source of water supply for coastal communities of southern New Jersey. In response to extensive use of the aquifer--nearly 21 million gallons per day in 1986--water levels have declined to about 100 feet below sea level near Atlantic City and remain below sea level throughout the coastal areas of southern New Jersey, raising concerns about the potential for saltwater intrusion into well fields. Water levels in the Atlantic City 800-foot sand have declined in response to pumping from the aquifer since the 1890's. Water levels in the first wells drilled into the Atlantic City 800-foot sand were above land surface, and water flowed continuously from the wells. By 1986, water levels were below sea level throughout most of the coastal areas. Under current conditions, wells near the coast derive most of their supply from lateral flow contributed from the unconfined part of the aquifer northwest of the updip limit of the confining unit that overlies the Atlantic City 800- foot sand. Ground water also flows laterally from offshore areas and leaks vertically through the overlying and underlying confining units into the Atlantic City 800-foot sand. The decline in water levels upsets the historical equilibrium between freshwater and ancient saltwater in offshore parts of the aquifer and permits the lateral movement of saltwater toward pumping centers. The rate of movement is accelerated as the decline in water levels increases. The chloride concentration of aquifer water 5.3 miles offshore of Atlantic City was measured as 77 mg/L (milligrams per liter) in 1985 at a U.S. Geological Survey observation well. Salty water has also moved toward wells in Cape May County. The confined, regional nature of the Atlantic City 800-foot sand permits water levels in Cape May County to decline in response to pumping in Atlantic County and vice versa. Historically, chloride concentrations as great as 1 ,510 mg/L have been reported for water in a former supply well in southern Cape May County. These data indicate that salty water has moved inland in Cape May County. Analysis of the chloride-concentration data indicates that ground water with a chloride concentration of 250 mg/L is within 4 miles of supply wells in Stone Harbor, Cape May County, and is about 10 miles offshore of supply wells near Atlantic City. Results of numerical simulations of ground-water flow were analyzed to determine the effects of four water-supply alternatives on water levels, the flow budget, and potential saltwater movement toward pumping centers during 1986-2040. In the supply alternatives, pumpage is (1) held constant at 1986 rates of pumpage; (2) increased by 35 percent at 1986 locations; (3) increased by 35 percent, but with relocation of some supply wells further inland; and (4) increased by 35 percent but with some of the increase derived from inland wells tapping the Kirkwood-Cohansey aquifer system rather than the Atlantic City 800-foot sand. Inland relocation of supply wells closer to the updip limit of the overlying confining unit results in the smallest decline in water levels and the smallest rate of ground-water flow between the offshore location of salty water and coastal supply wells. Increased pumpage from coastal supply wells results in the greatest water-level declines and the greatest increase in the rate of ground-water flow from offshore to coastal wells. Flow of undesirable salty ground water from offshore locations remains nearly the same as for current (1986) conditions when pumping rates do not change, and the flow-rate increase is smallest for the relocated pumpage (fourth) alternative. In comparing the two conditions of a 35-percent increase in pumpage, the flow from undesirable salty water positions is lessened and flow from the unconfined aquifer is increased when some of the pumping centers are relocated farther inland. Ground water from the 250-mg/L isochlor position does not reach supply wells during any simulated conditions predicted for 1986-2040. The analysis of the simulation, however, includes only advective freshwater flow from an estimated 250-mg/L isochlor position and does not include density effects. A chloride concentration data-collection network could be designed to monitor for saltwater intrusion and serve as an early warning system for the communities of southern Cape May County and the coastal communities near Atlantic City. Data from existing offshore wells could continue to serve as an early warning system for the Atlantic City area; however, observation wells south of Stone Harbor, in the Wildwood area, would be useful as an early warning system for southern Cape May County.

Development of an automated potable water bactericide monitoring unit

NASA Technical Reports Server (NTRS)

Walsh, J. M.; Brawner, C. C.; Sauer, R. L.

1975-01-01

A monitor unit has been developed that permits the direct determination of the level of elemental iodine, used for microbiological control, in a spacecraft potable water supply system. Salient features of unit include low weight, volume and maintenance requirements, complete automatic operation, no inflight calibration, no expendables (except electrical current) and high accuracy and precision. This unit is capable of providing a signal to a controller that, in turn, automatically adjusts the addition rate of iodine to the potable water system so that a predetermined level of iodine can be maintained. In addition, the monitor provides a reading whereby the crewman can verify that the proper amount of iodine (within a range) is present in the water. A development history of the monitor is presented along with its design and theory of operation. Also presented are the results generated through testing of the unit in a simulated Shuttle potable water system.

LEACHATE MIGRATION FROM A SOLID WASTE DISPOSAL FACILITY NEAR BISCAYNE NATIONAL PARK, SOUTH FLORIDA.

USGS Publications Warehouse

Waller, Bradley G.; Labowski, James L.

1987-01-01

Leachate from the Dade County Solid Waste Disposal Facility (SWDF) is migrating to the east (seaward) and to the south from the currently active disposal cell. Water levels and ground-water flow directions are strongly influenced by water-management practices. The SWDF is constructed over the salt-intruded part of the highly transmissive Biscayne aquifer and because of this, chloride ion concentrations and specific conductance levels could not be used as indicators of leachate concentrations. Leachate was detected in multi-depth wells located 75 meters to the south and 20 meters to the east of the active cell. Concentrations of water-quality indicators had mean concentrations generally 2 to 10 times higher than baseline conditions. Primary controls over leachate movement in the SWDF are water-management practices in the Black Creek and Gould Canals, configuration and integrity of the liner beneath the active cell, and low hydraulic gradients in the landfill area.

Hydrologic Record Extension of Water-Level Data in the Everglades Depth Estimation Network (EDEN) Using Artificial Neural Network Models, 2000-2006

USGS Publications Warehouse

Conrads, Paul; Roehl, Edwin A.

2007-01-01

The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level gaging stations, ground-elevation models, and water-surface models designed to provide scientists, engineers, and water-resource managers with current (2000-present) water-depth information for the entire freshwater portion of the greater Everglades. The U.S. Geological Survey Greater Everglades Priority Ecosystem Science provides support for EDEN and the goal of providing quality assured monitoring data for the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan. To increase the accuracy of the water-surface models, 25 real-time water-level gaging stations were added to the network of 253 established water-level gaging stations. To incorporate the data from the newly added stations to the 7-year EDEN database in the greater Everglades, the short-term water-level records (generally less than 1 year) needed to be simulated back in time (hindcasted) to be concurrent with data from the established gaging stations in the database. A three-step modeling approach using artificial neural network models was used to estimate the water levels at the new stations. The artificial neural network models used static variables that represent the gaging station location and percent vegetation in addition to dynamic variables that represent water-level data from the established EDEN gaging stations. The final step of the modeling approach was to simulate the computed error of the initial estimate to increase the accuracy of the final water-level estimate. The three-step modeling approach for estimating water levels at the new EDEN gaging stations produced satisfactory results. The coefficients of determination (R2) for 21 of the 25 estimates were greater than 0.95, and all of the estimates (25 of 25) were greater than 0.82. The model estimates showed good agreement with the measured data. For some new EDEN stations with limited measured data, the record extension (hindcasts) included periods beyond the range of the data used to train the artificial neural network models. The comparison of the hindcasts with long-term water-level data proximal to the new EDEN gaging stations indicated that the water-level estimates were reasonable. The percent model error (root mean square error divided by the range of the measured data) was less than 6 percent, and for the majority of stations (20 of 25), the percent model error was less than 1 percent.

Satellite altimetry and hydrologic modeling of poorly-gauged tropical watershed

NASA Astrophysics Data System (ADS)

Sulistioadi, Yohanes Budi

Fresh water resources are critical for daily human consumption. Therefore, a continuous monitoring effort over their quantity and quality is instrumental. One important model for water quantity monitoring is the rainfall-runoff model, which represents the response of a watershed to the variability of precipitation, thus estimating the discharge of a channel (Bedient and Huber, 2002, Beven, 2012). Remote sensing and satellite geodetic observations are capable to provide critical hydrological parameters, which can be used to support hydrologic modeling. For the case of satellite radar altimetry, limited temporal resolutions (e.g., satellite revisit period) prohibit the use of this method for a short (less than weekly) interval monitoring of water level or discharge. On the other hand, the current satellite radar altimeter footprints limit the water level measurement for rivers wider than 1 km (Birkett, 1998, Birkett et al., 2002). Some studies indeed reported successful retrieval of water level for small-size rivers as narrow as 80 m (Kuo and Kao, 2011, Michailovsky et al., 2012); however, the processing of current satellite altimetry signals for small water bodies to retrieve accurate water levels, remains challenging. To address this scientific challenge, this study poses two main objectives: (1) to monitor small (40--200 m width) and medium-sized (200--800 m width) rivers and lakes using satellite altimetry through identification and choice of the over-water radar waveforms corresponding to the appropriately waveform-retracked water level; and (2) to develop a rainfall-runoff hydrological model to represent the response of mesoscale watershed to the variability of precipitation. Both studies address the humid tropics of Southeast Asia, specifically in Indonesia, where similar studies do not yet exist. This study uses the Level 2 radar altimeter measurements generated by European Space Agency's (ESA's) Envisat (Environmental Satellite) mission. The first study proves that satellite altimetry provides a good alternative or the only means in some regions to measure the water level of medium-sized river (200--800 m width) and small lake (extent less than 1000 km 2) in Southeast Asia humid tropic with reasonable accuracy. In addition, the procedure to choose retracked Envisat altimetry water level heights via identification or selection of over water waveform shapes is reliable; therefore this study concluded that the use of waveform shape selection procedure should be a standard measure in determining qualified range measurements especially over small rivers and lakes. This study also found that Ice-1 is not necessarily the best retracker as reported by previous studies, among the four standard waveform retracking algorithms for Envisat altimetry observing hydrologic bodies. The second study modeled the response of the poorly-gauged watershed in the Southeast Asia's humid tropic through the application of Hydrologic Engineering Center -- Hydrologic Modeling System (HEC-HMS). The performance evaluation of HEC-HMS discharge estimation confirms a good match between the simulated discharges with the observed ones. As the result of precipitation data analysis, this study found that Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) is the preferred input forcing for the model, given the thorough evaluation of its relationship with field-measured precipitation data prior to its use as primary climatic forcing. This research also proposes a novel approach to process the TRMM precipitation estimation spatially through Thiessen polygon and area average hybrid method, which model the spatial distribution of TRMM data to match the spatial location of field meteorological stations. Through a simultaneous validation that compares the water level anomaly transformed from HEC-HMS simulated discharge and satellite altimetry measurement, this study found that satellite altimetry measures water level anomaly closer to the true water level anomaly than the water level anomaly converted from HEC-HMS simulated discharge. Some critical recommendations for future studies include the use of waveform shape selection procedure in the satellite altimetry based water level measurement of small and medium-sized rivers and small lakes, as well as the exploration to implement data assimilation between satellite altimetry and the hydrologic model for better discharge and water level estimations.

Mission Level Autonomy for USSV

NASA Technical Reports Server (NTRS)

Huntsberger, Terry; Stirb, Robert C.; Brizzolara, Robert

2011-01-01

On-water demonstration of a wide range of mission-proven, advanced technologies at TRL 5+ that provide a total integrated, modular approach to effectively address the majority of the key needs for full mission-level autonomous, cross-platform control of USV s. Wide baseline stereo system mounted on the ONR USSV was shown to be an effective sensing modality for tracking of dynamic contacts as a first step to automated retrieval operations. CASPER onboard planner/replanner successfully demonstrated realtime, on-water resource-based analysis for mission-level goal achievement and on-the-fly opportunistic replanning. Full mixed mode autonomy was demonstrated on-water with a seamless transition between operator over-ride and return to current mission plan. Autonomous cooperative operations for fixed asset protection and High Value Unit escort using 2 USVs (AMN1 & 14m RHIB) were demonstrated during Trident Warrior 2010 in JUN 2010

Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2011

USGS Publications Warehouse

Beman, Joseph E.

2012-01-01

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the basin human population from 1990 to 2000 and of about 22 percent increase from 2000 to 2010 also resulted in an increased demand for water. A network of wells was established by the U.S. Geological Survey in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2011), the network consists of 126 wells and piezometers (a piezometer is a specialized well open to a specific depth in the aquifer and is often of small diameter and nested with other piezometers open to different depths). This report presents water-level data collected by U.S. Geological Survey personnel at those 126 sites through water year 2011 to better help the Albuquerque Bernalillo County Water Utility Authority manage water use.

Taking climate change into estimation of long-term flood risks: A case of Devils Lake of North Dakota, USA

NASA Astrophysics Data System (ADS)

Kharel, G.; Kirilenko, A.

2014-12-01

Terminal lakes are heavily impacted by regional changes in climate. Devils Lake (DL) is a terminal lake located in the northeastern North Dakota of the US. Since 1990, following a shift in regional precipitation pattern, DL has encountered a 10 m water level rise, with over 400% increase in surface area and 600% increase in water volume, costing over $1.5 billion in mitigation. Currently, the lake is <1.5 m from spillover level to the nearby Sheyenne River with potential negative consequences for downstream water quality and flooding. Recently, the artificial outlets have been constructed and operated to divert DL water to the Sheyenne River amid legal and political pressure. Outlet construction however did not take into consideration possible changes in local climate. We modeled the DL basin ( 9,800 km2) hydrology using the Soil and Water Assessment Tool (SWAT) and estimated future water levels of DL for different outlet scenarios under three Intergovernmental Panel on Climate Change (IPCC) SRES scenarios (A1B, B1 & A2) for 2020s and 2050s. We evaluated model performance by comparing SWAT simulated daily streamflow outputs against the observed streamflow data recorded at 6 USGS water gauge locations within the basin. Future climate conditions in the region were estimated by combining historical weather data (1981-2010), 15 CMIP3 General Circulation Model projections from the IPCC data center, and stochastic downscaling methodology (LARS-WG). Our results indicate significant likelihood (7.3% ̶ 20.0%) of uncontrolled DL water overspill in the next few decades in the absence of outlets, with some members of GCM integration ensemble carrying over 85.0% and 95.0% overspill probability for 2020s and 2050s respectively. However, full-capacity outlets show radical reduction in overspill probability to partially mitigate the flooding problem by decreasing the average lake level by approximately 1.9 m and 1.5 m in 2020s and 2050s. Moreover, had there been outlet operation from the beginning of the flood episode since 1990s, not only the future overspill risks but also the current flooding extent would have been reduced significantly (Fig. 1).

The Applicability of TaqMan-Based Quantitative Real-Time PCR Assays for Detecting and Enumerating Cryptosporidium spp. Oocysts in the Environment

PubMed Central

Staggs, Sarah E.; Beckman, Erin M.; Keely, Scott P.; Mackwan, Reena; Ware, Michael W.; Moyer, Alan P.; Ferretti, James A.; Sayed, Abu; Xiao, Lihua; Villegas, Eric N.

2013-01-01

Quantitative real-time polymerase chain reaction (qPCR) assays to detect Cryptosporidium oocysts in clinical samples are increasingly being used to diagnose human cryptosporidiosis, but a parallel approach for detecting and identifying Cryptosporidium oocyst contamination in surface water sources has yet to be established for current drinking water quality monitoring practices. It has been proposed that Cryptosporidium qPCR-based assays could be used as viable alternatives to current microscopic-based detection methods to quantify levels of oocysts in drinking water sources; however, data on specificity, analytical sensitivity, and the ability to accurately quantify low levels of oocysts are limited. The purpose of this study was to provide a comprehensive evaluation of TaqMan-based qPCR assays, which were developed for either clinical or environmental investigations, for detecting Cryptosporidium oocyst contamination in water. Ten different qPCR assays, six previously published and four developed in this study were analyzed for specificity and analytical sensitivity. Specificity varied between all ten assays, and in one particular assay, which targeted the Cryptosporidium 18S rRNA gene, successfully detected all Cryptosporidium spp. tested, but also cross-amplified T. gondii, fungi, algae, and dinoflagellates. When evaluating the analytical sensitivity of these qPCR assays, results showed that eight of the assays could reliably detect ten flow-sorted oocysts in reagent water or environmental matrix. This study revealed that while a qPCR-based detection assay can be useful for detecting and differentiating different Cryptosporidium species in environmental samples, it cannot accurately measure low levels of oocysts that are typically found in drinking water sources. PMID:23805235

Multiscale modeling of a rectifying bipolar nanopore: explicit-water versus implicit-water simulations.

PubMed

Ható, Zoltán; Valiskó, Mónika; Kristóf, Tamás; Gillespie, Dirk; Boda, Dezsö

2017-07-21

In a multiscale modeling approach, we present computer simulation results for a rectifying bipolar nanopore at two modeling levels. In an all-atom model, we use explicit water to simulate ion transport directly with the molecular dynamics technique. In a reduced model, we use implicit water and apply the Local Equilibrium Monte Carlo method together with the Nernst-Planck transport equation. This hybrid method makes the fast calculation of ion transport possible at the price of lost details. We show that the implicit-water model is an appropriate representation of the explicit-water model when we look at the system at the device (i.e., input vs. output) level. The two models produce qualitatively similar behavior of the electrical current for different voltages and model parameters. Looking at the details of concentration and potential profiles, we find profound differences between the two models. These differences, however, do not influence the basic behavior of the model as a device because they do not influence the z-dependence of the concentration profiles which are the main determinants of current. These results then address an old paradox: how do reduced models, whose assumptions should break down in a nanoscale device, predict experimental data? Our simulations show that reduced models can still capture the overall device physics correctly, even though they get some important aspects of the molecular-scale physics quite wrong; reduced models work because they include the physics that is necessary from the point of view of device function. Therefore, reduced models can suffice for general device understanding and device design, but more detailed models might be needed for molecular level understanding.

Coastal circulation and water column properties off Kalaupapa National Historical Park, Molokai, Hawaii, 2008-2010

USGS Publications Warehouse

Storlazzi, Curt D.; Presto, Katherine; Brown, Eric K.

2011-01-01

More than 2.2 million measurements of oceanographic forcing and the resulting water-column properties were made off U.S. National Park Service's Kalaupapa National Historical Park on the north shore of Molokai, Hawaii, between 2008 and 2010 to understand the role of oceanographic processes on the health and sustainability of the area's marine resources. The tides off the Kalaupapa Peninsula are mixed semidiurnal. The wave climate is dominated by two end-members: large northwest Pacific winter swell that directly impacts the study site, and smaller, shorter-period northeast trade-wind waves that have to refract around the peninsula, resulting in a more northerly direction before propagating over the study site. The currents primarily are alongshore and are faster at the surface than close to the seabed; large wave events, however, tend to drive flow in a more cross-shore orientation. The tidal currents flood to the north and ebb to the south. The waters off the peninsula appear to be a mix of cooler, more saline, deeper oceanic waters and shallow, warmer, lower-salinity nearshore waters, with intermittent injections of freshwater, generally during the winters. Overall, the turbidity levels were low, except during large wave events. The low overall turbidity levels and rapid return to pre-event background levels following the cessation of forcing suggest that there is little fine-grained material. Large wave events likely inhibit the settlement of fine-grained sediment at the site. A number of phenomena were observed that indicate the complexity of coastal circulation and water-column properties in the area and may help scientists and resource managers to better understand the implications of the processes on marine ecosystem health.

Occurrence of contaminant accumulation in lead pipe scales from domestic drinking-water distribution systems.

PubMed

Schock, Michael R; Hyland, Robert N; Welch, Meghan M

2008-06-15

Previously, contaminants, such as AI, As, and Ra, have been shown to accumulate in drinking-water distribution system solids. Accumulated contaminants could be periodically released back into the water supply causing elevated levels at consumers taps, going undetected by most current regulatory monitoring practices and consequently constituting a hidden risk. The objective of this study was to determine the occurrence of over 40 major scale constituents, regulated metals, and other potential metallic inorganic contaminants in drinking-water distribution system Pb (lead) or Pb-lined service lines. The primary method of analysis was inductively coupled plasma-atomic emission spectroscopy, following complete decomposition of scale material. Contaminants and scale constituents were categorized by their average concentrations, and many metals of potential health concern were found to occur at levels sufficient to result in elevated levels at the consumer's taps if they were to be mobilized. The data indicate distinctly nonconservative behavior for many inorganic contaminants in drinking-water distribution systems. This finding suggests an imminent need for further research into the transport and fate of contaminants throughout drinking-water distribution system pipes, as well as a re-evaluation of monitoring protocols in order to more accurately determine the scope and levels of potential consumer exposure.

The NASA/USDA Reservoir and Lake Monitor: Present and Future Capabilities and Water Resources Applications

NASA Astrophysics Data System (ADS)

Birkett, C. M.; Beckley, B. D.; Reynolds, C. A.; Brakenridge, G. R.; Ricko, M.

2013-12-01

The USDA/NASA Global Reservoir and Lake Monitor (GRLM) provides satellite-based surface water level products for large reservoirs and lakes around the world. It utilizes a suite of NASA/CNES and ESA radar altimetry data sets and outputs near real time and archival products via a web interface. Several stakeholders utilize the products for applications that focus on water resources management and natural hazards mitigation, particularly in arid and semi-arid regions. The satellite data sets prove particularly useful in un-gauged or poorly gauged basins where in situ data is sparse. Here, we present water-level product examples based on data from the NASA/CNES Jason-2/OSTM mission, and the new ISRO/CNES SARAL mission. We also demonstrate product application from the viewpoint of various end users who have interests ranging from crop production and fisheries, to regional security and climate change. In the current phase of the program the team is also looking to the potential of additional lake/reservoir products such as areal extent (NASA/MODIS), lake volume variations (combined altimetry/imagery), and model-derived water levels, that will enhance the GRLM via improved observation and prediction, and provide a more global lake basin monitoring capability. Surface water level variations for Lake Nasser.

Seasonal changes and driving forces of inflow and outflow through the Bohai Strait

NASA Astrophysics Data System (ADS)

Zhang, Zhixin; Qiao, Fangli; Guo, Jingsong; Guo, Binghuo

2018-02-01

This work focuses on analyzing seasonal variation of inflow and outflow through the Bohai Strait that greatly affect the marine environment in the Bohai Sea, using observational data including sea bed mounted acoustic Doppler current profiler currents, CTD salinity data on deck, sea level anomalies of coastal tide gauge stations, and climatological monthly sea level anomalies from Archiving, Validation and Interpretation of Satellite Oceanographic data. Our results show three patterns of outflow and inflow through the Bohai Strait. The first is such that outflow and inflow occur respectively in the southern and northern parts of the strait, as in the traditional understanding. Our results suggest that this pattern occurs only in autumn and winter. Beginning in late September, Ekman currents driven by the northwesterly monsoon carry Bohai Sea water that piles up in the southern part of that sea and then exits eastward to the Yellow Sea. In this process, the pressure and current fields are continuously adjusted, until a quasi balance state between wind stress, Coriolis force and pressure gradient force is reached in winter. Inflow with a compensating property through the northern channel is close to the outflow through the southern channel in winter. The second pattern is a single inflow in spring, and the current and pressure fields are in adjustment. In early spring, the northwesterly monsoon ceases, Yellow Sea water enters the Bohai Sea under the pressure gradient force. With southeasterly monsoon establishment and strengthening, northern Yellow Sea water continually flows into the Bohai Sea and causes sea level rise northward. In the third pattern, outflow is much greater than inflow in summer. The currents run eastward in the central Bohai Sea and then enter the northern Yellow Sea through the northern channel and upper layer of the southern channel, while a westward current with a compensating property enters via the lower layer of the southern channel. Larger net transport is through the Bohai Strait to the northern Yellow Sea, which is related to strong precipitation and runoff into the Bohai Sea.

Flood-inundation maps for the St. Marys River at Fort Wayne, Indiana

USGS Publications Warehouse

Menke, Chad D.; Kim, Moon H.; Fowler, Kathleen K.

2012-01-01

Digital flood-inundation maps for a 9-mile reach of the St. Marys River that extends from South Anthony Boulevard to Main Street at Fort Wayne, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the City of Fort Wayne. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site, depict estimates of the areal extent of flooding corresponding to selected water levels (stages) at the USGS streamgage 04182000 St. Marys River near Fort Wayne, Ind. Current conditions at the USGS streamgages in Indiana may be obtained from the National Water Information System: Web Interface. In addition, the information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system. The NWS forecasts flood hydrographs at many places that are often collocated at USGS streamgages. That forecasted peak-stage information, also available on the Internet, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, water-surface profiles were simulated for the stream reach by means of a hydraulic one-dimensional step-backwater model. The model was calibrated using the most current stage-discharge relation at the USGS streamgage 04182000 St. Marys River near Fort Wayne, Ind. The hydraulic model was then used to simulate 11 water-surface profiles for flood stages at 1-ft intervals referenced to the streamgage datum and ranging from bankfull to approximately the highest recorded water level at the streamgage. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from Light Detection and Ranging (LiDAR) data) in order to delineate the area flooded at each water level. A flood inundation map was generated for each water-surface profile stage (11 maps in all) so that for any given flood stage users will be able to view the estimated area of inundation. The availability of these maps along with current stage from USGS streamgages and forecasted stream stages from the NWS provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post flood recovery efforts.

Flood-inundation maps for the East Fork White River at Columbus, Indiana

USGS Publications Warehouse

Lombard, Pamela J.

2013-01-01

Digital flood-inundation maps for a 5.4-mile reach of the East Fork White River at Columbus, Indiana, from where the Flatrock and Driftwood Rivers combine to make up East Fork White River to just upstream of the confluence of Clifty Creek with the East Fork White River, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation, depict estimates of the areal extent of flooding corresponding to selected water levels (stages) at USGS streamgage 03364000, East Fork White River at Columbus, Indiana. Current conditions at the USGS streamgage may be obtained on the Internet from the USGS National Water Information System (http://waterdata.usgs.gov/in/nwis/uv/?site_no=03364000&agency_cd=USGS&). The National Weather Service (NWS) forecasts flood hydrographs for the East Fork White River at Columbus, Indiana at their Advanced Hydrologic Prediction Service (AHPS) flood warning system Website (http://water.weather.gov/ahps/), that may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relation at USGS streamgage 03364000, East Fork White River at Columbus, Indiana. The calibrated hydraulic model was then used to determine 15 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from bankfull to approximately the highest recorded water level at the streamgage. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from Light Detection and Ranging (LiDAR) data), having a 0.37-ft vertical accuracy and a 1.02 ft horizontal accuracy), in order to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage at Columbus, Indiana, and forecasted stream stages from the NWS will provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post-flood recovery efforts.

Flood-inundation maps for the Wabash River at Terre Haute, Indiana

USGS Publications Warehouse

Lombard, Pamela J.

2013-01-01

Digital flood-inundation maps for a 6.3-mi reach of the Wabash River from 0.1 mi downstream of the Interstate 70 bridge to 1.1 miles upstream of the Route 63 bridge, Terre Haute, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent of flooding corresponding to select water levels (stages) at the USGS streamgage Wabash River at Terre Haute (station number 03341500). Current conditions at the USGS streamgage may be obtained on the Internet from the USGS National Water Information System (http://waterdata.usgs.gov/in/nwis/uv/?site_no=03341500&agency_cd=USGS&p"). In addition, the same data are provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps//). Within this system, the NWS forecasts flood hydrographs for the Wabash River at Terre Haute that may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated using the most current stage-discharge relation at the Wabash River at the Terre Haute streamgage. The hydraulic model was then used to compute 22 water-surface profiles for flood stages at 1-ft interval referenced to the streamgage datum and ranging from bank-full to approximately the highest recorded water level at the streamgage. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from Light Detection and Ranging (LiDAR) data having a 0.37-ft vertical accuracy and a 1.02-ft horizontal accuracy) to delineate the area flooded at each water level. The availability of these maps along with Internet information regarding the current stage from the USGS streamgage and forecasted stream stages from the NWS can provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post flood recovery efforts.

Rural water supply in Kerala, India: How to emerge from a low-level equilibrium trap

NASA Astrophysics Data System (ADS)

Singh, Bhanwar; Ramasubban, Radhika; Bhatia, Ramesh; Briscoe, John; Griffin, Charles C.; Kim, Chongchun

1993-07-01

Large quantities of financial and human resources have been devoted to improving rural water supplies in developing countries over the past two decades. Many projects have been successful, but many have failed to meet the needs of the intended beneficiaries. Evidence of the failures lies in the unused and poorly maintained systems that are scattered throughout rural areas of the developing world. The current situation in water supply in rural Kerala, India, reflects this general observation and can be described as a "low-level equilibrium trap." Water systems provide a low level of service with few yard taps. The monthly tariff for water from household connections is low. With few connectors and low tariffs, little revenue is generated beyond subsidies provided by the government. The water authority can afford to maintain the system up to a level at which the reliability of service is low, forcing consumers to supplement piped water from traditional sources. This study analyzes contingent valuation data collected in three areas of Kerala to evaluate the possibility of lifting the system out of this trap. The analysis shows that by making a few critical policy changes, encouraging private connections and financing those connections through higher tariffs, the system can ratchet up to a "high-level equilibrium" in which there are many connectors, monthly revenues are greatly increased, and consumer welfare improves. Such a system would be better financed, making it possible to improve the reliability and quality of the service.

Importance of Antecedent Beach and Surf-Zone Morphology to Wave Runup Predictions

DTIC Science & Technology

2016-10-01

position on the dune, the laser reflects well off of the water surface when foam is present (blue dots, Figure 1B). Maximum range of measurement...depends upon the amount of breaking and foam present in the surf-zone at any given time, but rarely exceeds 150 m for this laser scanner. Drawbacks to...determined by reverse-shoaling data from the FRF’s 11 m Acoustic Wave and Current (AWAC) profiler to deep water values. Local water levels (tide and surge

Study on the Variation of Groundwater Level under Time-varying Recharge

NASA Astrophysics Data System (ADS)

Wu, Ming-Chang; Hsieh, Ping-Cheng

2017-04-01

The slopes of the suburbs come to important areas by focusing on the work of soil and water conservation in recent years. The water table inside the aquifer is affected by rainfall, geology and topography, which will result in the change of groundwater discharge and water level. Currently, the way to obtain water table information is to set up the observation wells; however, owing to that the cost of equipment and the wells excavated is too expensive, we develop a mathematical model instead, which might help us to simulate the groundwater level variation. In this study, we will discuss the groundwater level change in a sloping unconfined aquifer with impermeable bottom under time-varying rainfall events. Referring to Child (1971), we employ the Boussinesq equation as the governing equation, and apply the General Integral Transforms Method (GITM) to analyzing the groundwater level after linearizing the Boussinesq equation. After comparing the solution with Verhoest & Troch (2000) and Bansal & Das (2010), we get satisfactory results. To sum up, we have presented an alternative approach to solve the linearized Boussinesq equation for the response of groundwater level in a sloping unconfined aquifer. The present analytical results combine the effect of bottom slope and the time-varying recharge pattern on the water table fluctuations. Owing to the limitation and difficulty of measuring the groundwater level directly, we develop such a mathematical model that we can predict or simulate the variation of groundwater level affected by any rainfall events in advance.

Records of the drilled wells of the island of Oahu, Hawaii

USGS Publications Warehouse

Stearns, Harold T.; Vaksvik, Knute N.

1938-01-01

The description, location, log and meter tests of all the drilled wells on Oahu are given herein as of March 1 1938. Except for the discharges of plantation wells, which are published on pages 275 to 322 of Bulletin 1, head, chloride, and discharge records are listed only to the close of 1934, the date when this report was compiled. All head measurements and salt determinations made by the U.S. Geological Survey since 1934 will be found in the annual U.S. Geological Survey Water-Supply Papers entitled “Water levels and artesian pressure in observation wells in the United States.” Records of wells in the district of Honolulu are currently printed in the biennial reports of the Board of Water Supply, Honolulu. Most of the records of the plantation wells have been furnished by the owners.Plate 2 shows the location of the wells, whether they are sealed, and whether the log is known. The static level or head of a well is the height above mean sea level to which the water will rise when all flow from the well is shut off. In the nonartesian wells the static level is the level of the water table of the basal zone of saturation in the basalts of the Koolau and Waianae volcanic series. Many of the wells are subartesian; that is, the water stands in the well above the level at which it was first encountered but does not overflow.

Incubation success and habitat selection of shore-spawning kokanee Onchorhynchus nerka: effects of water level regulation and habitat characteristics.

USGS Publications Warehouse

Whitlock, Steven L.; Quist, Michael C.; Dux, Andrew M.

2014-01-01

Changes to water-level regimes have been known to restructure fish assemblages and interfere with the population dynamics of both littoral and pelagic species. The effect of altered water-level regimes on shore-spawning kokanee Oncorhynchus nerka incubation success was evaluated using a comprehensive in situ study in Lake Pend Oreille, ID, USA. Survival was not related to substrate size composition or depth, indicating that shore-spawning kokanee do not currently receive a substrate-mediated survival benefit from higher winter water levels. Substrate composition also did not differ among isobaths in the nearshore area. On average, the odds of an egg surviving to the preemergent stage were more than three times greater for sites in downwelling areas than those lacking downwelling. This study revealed that shoreline spawning habitat is not as limited as previously thought. Downwelling areas appear to contribute substantially to shore-spawning kokanee recruitment. This research illustrates the value of rigorous in situ studies both for testing potential mechanisms underlying population trends and providing insight into spawning habitat selection.

Diet change—a solution to reduce water use?

NASA Astrophysics Data System (ADS)

Jalava, M.; Kummu, M.; Porkka, M.; Siebert, S.; Varis, O.

2014-07-01

Water and land resources are under increasing pressure in many parts of the globe. Diet change has been suggested as a measure to contribute to adequate food security for the growing population. This paper assesses the impact of diet change on the blue and green water footprints of food consumption. We first compare the water consumption of the current diets with that of a scenario where dietary guidelines are followed. Then, we assess these footprints by applying four scenarios in which we gradually limit the amount of protein from animal products to 50%, 25%, 12.5% and finally 0% of the total protein intake. We find that the current water use at the global scale would be sufficient to secure a recommended diet and worldwide energy intake. Reducing the animal product contribution in the diet would decrease global green water consumption by 6%, 11%, 15% and 21% within the four applied scenarios, while for blue water, the reductions would be 4%, 6%, 9% and 14%. In Latin America, Europe, Central and Eastern Asia and Sub-Saharan Africa, diet change mainly reduces green water use, while in the Middle East region, North America, Australia and Oceania, both blue and green water footprints decrease considerably. At the same time, in South and Southeast Asia, diet change does not result in decreased water use. Our results show that reducing animal products in the human diet offers the potential to save water resources, up to the amount currently required to feed 1.8 billion additional people globally; however, our results show that the adjustments should be considered on a local level.

Modeling river discharge and sediment transport in the Wax Lake-Atchafalaya basin with remote sensing parametrization.

NASA Astrophysics Data System (ADS)

Simard, M.; Liu, K.; Denbina, M. W.; Jensen, D.; Rodriguez, E.; Liao, T. H.; Christensen, A.; Jones, C. E.; Twilley, R.; Lamb, M. P.; Thomas, N. A.

2017-12-01

Our goal is to estimate the fluxes of water and sediments throughout the Wax Lake-Atchafalaya basin. This was achieved by parametrization of a set of 1D (HEC-RAS) and 2D (DELFT3D) hydrology models with state of the art remote sensing measurements of water surface elevation, water surface slope and total suspended sediment (TSS) concentrations. The model implementations are spatially explicit, simulating river currents, lateral flows to distributaries and marshes, and spatial variations of sediment concentrations. Three remote sensing instruments were flown simultaneously to collect data over the Wax Lake-Atchafalaya basin, and along with in situ field data. A Riegl Lidar was used to measure water surface elevation and slope, while the UAVSAR L-band radar collected data in repeat-pass interferometric mode to measure water level change within adjacent marshes and islands. These data were collected several times as the tide rose and fell. AVRIS-NG instruments measured water surface reflectance spectra, used to estimate TSS. Bathymetry was obtained from sonar transects and water level changes were recorded by 19 water level pressure transducers. We used several Acoustic Doppler Current Profiler (ADCP) transects to estimate river discharge. The remotely sensed measurements of water surface slope were small ( 1cm/km) and varied slightly along the channel, especially at the confluence with bayous and the intra-coastal waterway. The slope also underwent significant changes during the tidal cycle. Lateral fluxes to island marshes were mainly observed by UAVSAR close to the distributaries. The extensive remote sensing measurements showed significant disparity with the hydrology model outputs. Observed variations in water surface slopes were unmatched by the model and tidal wave propagation was much faster than gauge measurements. The slope variations were compensated for in the models by tuning local lateral fluxes, bathymetry and riverbed friction. Overall, the simpler 1D model could best simulate observed tidal wave propagation and water surface slope. The complexity of the 2D model requires further quantification of parameter sensitivity and improvement of the parametrization routine.

Politics of innovation in multi-level water governance systems

NASA Astrophysics Data System (ADS)

Daniell, Katherine A.; Coombes, Peter J.; White, Ian

2014-11-01

Innovations are being proposed in many countries in order to support change towards more sustainable and water secure futures. However, the extent to which they can be implemented is subject to complex politics and powerful coalitions across multi-level governance systems and scales of interest. Exactly how innovation uptake can be best facilitated or blocked in these complex systems is thus a matter of important practical and research interest in water cycle management. From intervention research studies in Australia, China and Bulgaria, this paper seeks to describe and analyse the behind-the-scenes struggles and coalition-building that occurs between water utility providers, private companies, experts, communities and all levels of government in an effort to support or block specific innovations. The research findings suggest that in order to ensure successful passage of the proposed innovations, champions for it are required from at least two administrative levels, including one with innovation implementation capacity, as part of a larger supportive coalition. Higher governance levels can play an important enabling role in facilitating the passage of certain types of innovations that may be in competition with currently entrenched systems of water management. Due to a range of natural biases, experts on certain innovations and disciplines may form part of supporting or blocking coalitions but their evaluations of worth for water system sustainability and security are likely to be subject to competing claims based on different values and expertise, so may not necessarily be of use in resolving questions of "best courses of action". This remains a political values-based decision to be negotiated through the receiving multi-level water governance system.

Amoeba-related health risk in drinking water systems: could monitoring of amoebae be a complementary approach to current quality control strategies?

PubMed

Codony, Francesc; Pérez, Leonardo Martín; Adrados, Bárbara; Agustí, Gemma; Fittipaldi, Mariana; Morató, Jordi

2012-01-01

Culture-based methods for fecal indicator microorganisms are the standard protocol to assess potential health risk from drinking water systems. However, these traditional fecal indicators are inappropriate surrogates for disinfection-resistant fecal pathogens and the indigenous pathogens that grow in drinking water systems. There is now a range of molecular-based methods, such as quantitative PCR, which allow detection of a variety of pathogens and alternative indicators. Hence, in addition to targeting total Escherichia coli (i.e., dead and alive) for the detection of fecal pollution, various amoebae may be suitable to indicate the potential presence of pathogenic amoeba-resisting microorganisms, such as Legionellae. Therefore, monitoring amoeba levels by quantitative PCR could be a useful tool for directly and indirectly evaluating health risk and could also be a complementary approach to current microbial quality control strategies for drinking water systems.

Ground-water hydrology and simulated effects of development in the Milford area, an arid basin in southwestern Utah

USGS Publications Warehouse

Mason, James L.

1998-01-01

A three-dimensional, finite-difference model was constructed to simulate ground-water flow in the Milford area. The purpose of the study was to evaluate present knowledge and concepts of the groundwater system, to analyze the ability of the model to represent past and current (1984) conditions, and to estimate the effects of various groundwater development alternatives. The alternative patterns of groundwater development might prove effective in capturing natural discharge from the basin-fill aquifer while limiting water-level declines. Water levels measured during this study indicate that ground water in the Milford area flows in a northwesterly direction through consolidated rocks in the northern San Francisco Mountains toward Sevier Lake. The revised potentiometric surface shows a large area for probable basin outflow, indicating that more water leaves the Milford area than the 8 acre-feet per year estimated previously.Simulations made to calibrate the model were able to approximate steady-state conditions for 1927, before ground-water development began, and transient conditions for 1950-82, during which groundwater withdrawal increased. Basin recharge from the consolidated rocks and basin outflow were calculated during the calibration process. Transient simulations using constant and variable recharge from surface water were made to test effects of large flows in the Beaver River.Simulations were made to project water-level declines over a 37- year period (1983-2020) using the present pumping distribution. Ground-water withdrawals were simulated at 1, 1.5, and 2 times the 1979-82 average rate.The concepts of "sustained" yield, ground-water mining, and the capture of natural discharge were tested using several hypothetical pumping distributions over a 600-year simulation period. Simulations using concentrated pumping centers were the least efficient at capturing natural discharge and produced the largest water-level declines. Simulations using strategically placed ground-water withdrawals in the discharge area were the most efficient at eliminating natural discharge with small water-level declines.

Science Advisory Board Evaluation of the Effectiveness of Partial Lead Service Line Replacements

EPA Pesticide Factsheets

Report of the Science Advisory Board (SAB) to evaluate the current scientific data to determine the effectiveness of partial lead service line replacements (PLSLR) in reducing drinking water lead levels.

Hydrological state of the Large Aral Sea in the fall season of 2013

NASA Astrophysics Data System (ADS)

Izhitskiy, Alexander; Zavialov, Peter

2014-05-01

We report here the results of the latest expedition of the Shirshov Institute to the Aral Sea. The survey encompassed 8 field days in October-November, 2013. Direct measurements of thermohaline characteristics and water currents were conducted in the western basin of the Large Aral Sea during the expedition. Vertical profiles of temperature and salinity were obtained using a CTD profiler at 9 stations, situated on two cross-sections of the western basin. Four mooring stations equipped with current meters, as well as pressure gauges, were deployed for 4-6 days on the slopes of the deepest portion of the western basin. A portable automatic meteorological station, continuously recording the variability of wind and principal meteorological parameters, was installed near the mooring sites. Analysis of the current measurements data along with the meteorological data records demonstrated the current velocity and level anomalies responded energetically to winds. Correlation analysis of the velocity series versus the wind stress allowed to quantify the response of the system to the wind forcing. Together with the similar results of more earlier surveys, recently collected data shows that the mean surface circulation of the western basin remains anti-cyclonic under the predominant winds. Character of the interannual variability of salinity values in the Aral Sea water manifested increase in the surface layer during last 5 years. On the other hand, salinity values in the bottom layer appear to be decreased due to ceasing of the influence of the interbasin water exchange since 2010. Water level of the Large Aral Sea is still falling. Assessment of the on-going changes holds promise to help predicting the subsequent state of the Aral Sea region.

Quantifying the Bering Strait Oceanic Fluxes and their Impacts on Sea-Ice and Water Properties in the Chukchi and Beaufort Seas and Western Arctic Ocean for 2013-2014

DTIC Science & Technology

2014-09-30

Right) Sea Surface Temperature (SST) MODIS/Aqua level 1 image from 26th August 2004 (courtesy of Ocean Color Data Processing Archive, NASA/Goddard...was extremely good. The ADCPs and lower level temperature and salinity sensors all returned complete records. All 3 moorings also carried upper... Pavlov , and M. Kulakov (1999), The Siberian Coastal Current: a wind- and buoyancy-forced Arctic coastal current, J. Geophys. Res., 104(C12), 29697

Predicted effects on ground water of construction of Divide Cut section, Tennessee-Tombigbee Waterway, northeastern Mississippi, using a digital model

USGS Publications Warehouse

McBride, Mark S.

1981-01-01

The Tennessee-Tombigbee Waterway, connecting the Tennessee River in northeastern Mississippi with the Gulf of Mexico, is currently (1980) under construction. The Divide Section, the northernmost 39 miles of the Waterway, will consist, from north to south, of (1) a dredged channel, (2) the Divide Cut, and (3) an artifical lake impounded by the Bay Springs Dam. In all three , water will be at Tennessee River level. A three-dimensional digital model covering 3,273 square miles was constructed to simulate ground-water flow in the Gordo and Eutaw Formations and the Coffee Sand in the vicinity of the Divide Section. The model was calibrated to preconstruction water levels, then used to simulate the effects of stresses imposed by the construction of the Divide Section. The model indicates that the system stabilizes after major changes in conditions within a few months. The Divide Cut acts as a drain, lowering water levels as much as 55 feet. Drawdowns of 5 feet occur as much as 8 miles from the Cut. The 80-foot-high Bay Springs Dam raises ground-water levels by 5 feet as far as 6 miles from its impoundment. Drawdown is not likely to affect public water supplies significantly, but probably will adversely affect a relatively small number of private wells. (USGS)

Economic evaluation of the new U.S. arsenic standard for drinking water: A disaggregate approach

NASA Astrophysics Data System (ADS)

Cho, Yongsung; Easter, K. William; Konishi, Yoshifumi

2010-10-01

We evaluate the welfare consequences of the new U.S. arsenic standard for drinking water, using contingent valuation survey and recent cost data for the small rural community water systems in Minnesota that have had arsenic levels above the new standard prior to its implementation. Using variation in actual arsenic levels and an elicitation method that recognizes the dependence of welfare values on both ambient arsenic concentrations and self-protection levels, the welfare values of the new arsenic rule are estimated at 6-23 per household per year for communities with less than 10 μg/L of arsenic currently in their water and 31-78 for communities with more than 10 μg/L of arsenic. Given cost estimates of 230-2,006 and the fact that a substantial portion of the cost needs to be internally financed, the new rule may have substantially negative welfare consequences for a number of small communities.

NATIONAL GEODATABASE OF TIDAL STREAM POWER RESOURCE IN USA

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

Smith, Brennan T; Neary, Vincent S; Stewart, Kevin M

2012-01-01

A geodatabase of tidal constituents is developed to present the regional assessment of tidal stream power resource in the USA. Tidal currents are numerically modeled with the Regional Ocean Modeling System (ROMS) and calibrated with the available measurements of tidal current speeds and water level surfaces. The performance of the numerical model in predicting the tidal currents and water levels is assessed by an independent validation. The geodatabase is published on a public domain via a spatial database engine with interactive tools to select, query and download the data. Regions with the maximum average kinetic power density exceeding 500 W/m2more » (corresponding to a current speed of ~1 m/s), total surface area larger than 0.5 km2 and depth greater than 5 m are defined as hotspots and documented. The regional assessment indicates that the state of Alaska (AK) has the largest number of locations with considerably high kinetic power density, followed by, Maine (ME), Washington (WA), Oregon (OR), California (CA), New Hampshire (NH), Massachusetts (MA), New York (NY), New Jersey (NJ), North and South Carolina (NC, SC), Georgia (GA), and Florida (FL).« less

Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: II. Water Level Models, Floodplain Wetland Inundation, and System Zones

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

Jay, David A.; Borde, Amy B.; Diefenderfer, Heida L.

Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetlandmore » hydrologic regimes at different locations on the river floodplain. A new predictive tool is introduced and validated, the potential SEV (pSEV), which can reduce the need for extensive new data collection in wetland restoration planning. Models of water levels and inundation frequency distinguish four zones encompassing eight reaches. The system zones are the wave- and current-dominated Entrance to river kilometer (rkm) 5; the Estuary (rkm-5 to 87), comprised of a lower reach with salinity, the energy minimum (where the turbidity maximum normally occurs), and an upper estuary reach without salinity; the Tidal River (rkm-87 to 229), with lower, middle, and upper reaches in which river flow becomes increasingly dominant over tides in determining water levels; and the steep and weakly tidal Cascade (rkm-229 to 234) immediately downstream from Bonneville Dam. The same zonation is seen in the water levels of floodplain stations, with considerable modification of tidal properties. The system zones and reaches defined here reflect geological features and their boundaries are congruent with five wetland vegetation zones« less

Issues that Drive Waste Management Technology Development for Space Missions

NASA Technical Reports Server (NTRS)

Fisher, John W.; Levri, Julie A.; Hogan, John A.; Wignarajah, Kanapathipillai

2005-01-01

Waste management technologies for space life support systems are currently at low development levels. Manual compaction of waste in plastic bags and overboard disposal to earth return vehicles are the primary current waste management methods. Particularly on future missions, continuance of current waste management methods would tend to expose the crew to waste hazards, forfeit recoverable resources such as water, consume valuable crew time, contaminate planetary surfaces, and risk return to Earth of extraterrestrial life. Improvement of waste management capabilities is needed for adequate management of wastes. Improvements include recovery of water and other resources, conversion of waste to states harmless to humans, long-term containment of wastes, and disposal of waste. Current NASA requirements documents on waste management are generally not highly detailed. More detailed requirements are needed to guide the development of waste management technologies that will adequately manage waste. In addition to satisfying requirements, waste management technologies must also recover resources. Recovery of resources such as water and habitat volume can reduce mission cost. This paper explores the drivers for waste management technology development including requirements and resource recovery.

Flood-inundation maps for the Big Blue River at Shelbyville, Indiana

USGS Publications Warehouse

Fowler, Kathleen K.

2017-02-13

Digital flood-inundation maps for a 4.1-mile reach of the Big Blue River at Shelbyville, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The floodinundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at https://water. usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Big Blue River at Shelbyville, Ind. (station number 03361500). Near-real-time stages at this streamgage may be obtained from the USGS National Water Information System at https://waterdata. usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service at https://water.weather.gov/ ahps/, which also forecasts flood hydrographs at this site (SBVI3). Flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relation at the Big Blue River at Shelbyville, Ind., streamgage. The calibrated hydraulic model was then used to compute 12 water-surface profiles for flood stages referenced to the streamgage datum and ranging from 9.0 feet, or near bankfull, to 19.4 feet, the highest stage of the current stage-discharge rating curve. The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from light detection and ranging [lidar] data having a 0.98-foot vertical accuracy and 4.9-foot horizontal resolution) to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage at the Big Blue River at Shelbyville, Ind., and forecasted stream stages from the NWS, will provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post-flood recovery efforts.

Determination of water environment standards based on water quality criteria in China: Limitations and feasibilities.

PubMed

Wang, Tieyu; Zhou, Yunqiao; Bi, Cencen; Lu, Yonglong; He, Guizhen; Giesy, John P

2017-07-01

There is a need to formulate water environment standards (WESs) from the current water quality criteria (WQC) in China. To this end, we briefly summarize typical mechanisms applied in several countries with longer histories of developing WESs, and three limitations to formulating WESs in China were identified. After analyzing the feasibility factors including economic development, scientific support capability and environmental policies, we realized that China is still not ready for a complete change from its current nation-wide unified WES system to a local-standard-based system. Thus, we proposed a framework for transformation from WQC to WESs in China. The framework consists of three parts, including responsibilities, processes and policies. The responsibilities include research authorization, development of guidelines, and collection of information, at both national and local levels; the processes include four steps and an impact factor system to establish water quality standards; and the policies include seven specific proposals. Copyright © 2016. Published by Elsevier B.V.

The 21st Century Challenges and the Food-Energy-Water-Security (FEWS) Nexus in the Middle East Region

NASA Astrophysics Data System (ADS)

Moradkhani, H.; Hameed, M.

2017-12-01

Developing countries have experienced crucial conditions in meeting the needs for food, energy, and water security. This paper presents a country-level quantitative assessment of the current issues associated with the Food-Energy-Water-Security (FEWS) Nexus in the Middle East region. In this study, sixteen countries in the Middle East region are chosen, namely, Arabian Peninsula, Iran, Syria, Lebanon, Israel, Palestine, Egypt, and Turkey. The most recent datasets are used to study and analyze the factors that have emerged the demand to understand and manage the linkage of FEW systems in the region. Water scarcity, extreme events, population growth, urbanization, economic growth, poverty, and political stability are found to be the key drivers of the current challenges in the Middle East region. Additionally, the results suggest that these factors have created a subsequent stress on FEW resources specifically on water sector in the region. Therefore, more attention is required to sustain the FEW resources and cope with the socio-economic development.

Estimating Agricultural Water Use using the Operational Simplified Surface Energy Balance Evapotranspiration Estimation Method

NASA Astrophysics Data System (ADS)

Forbes, B. T.

2015-12-01

Due to the predominantly arid climate in Arizona, access to adequate water supply is vital to the economic development and livelihood of the State. Water supply has become increasingly important during periods of prolonged drought, which has strained reservoir water levels in the Desert Southwest over past years. Arizona's water use is dominated by agriculture, consuming about seventy-five percent of the total annual water demand. Tracking current agricultural water use is important for managers and policy makers so that current water demand can be assessed and current information can be used to forecast future demands. However, many croplands in Arizona are irrigated outside of areas where water use reporting is mandatory. To estimate irrigation withdrawals on these lands, we use a combination of field verification, evapotranspiration (ET) estimation, and irrigation system qualification. ET is typically estimated in Arizona using the Modified Blaney-Criddle method which uses meteorological data to estimate annual crop water requirements. The Modified Blaney-Criddle method assumes crops are irrigated to their full potential over the entire growing season, which may or may not be realistic. We now use the Operational Simplified Surface Energy Balance (SSEBop) ET data in a remote-sensing and energy-balance framework to estimate cropland ET. SSEBop data are of sufficient resolution (30m by 30m) for estimation of field-scale cropland water use. We evaluate our SSEBop-based estimates using ground-truth information and irrigation system qualification obtained in the field. Our approach gives the end user an estimate of crop consumptive use as well as inefficiencies in irrigation system performance—both of which are needed by water managers for tracking irrigated water use in Arizona.

Well waters fluoride in Enugu, Nigeria.

PubMed

Ogbu, I Si; Okoro, O Io; Ugwuja, E I

2012-04-01

Abnormal fluoride levels in drinking water have been associated with adverse health effects. To determine the fluoride content of well waters in Enugu, southeastern Nigeria, water samples from 50 artisan wells chosen by multistage sampling procedure from the 5 zones of Enugu municipality were analyzed in duplicates for their fluoride content. The zonal mean values were 0.60, 0.70, 0.62, 0.62, and 0.63 mg/L for Abakpa Nike, Achara Layout, Obiagu/ Ogui, Trans Ekulu and Uwani, respectively (p<0.05). The mean value for the whole city was 0.63 mg/L. Although, the mean level of fluoride recorded in this study is currently within safe limits (1.5 mg/L, WHO 2011), it is important to monitor continuously the fluoride content of well waters in the municipality in view of the increasing industrial activities going on in the city and heavy reliance on well water for domestic purposes and the widespread use of consumer products containing fluoride.

User’s manual to update the National Wildlife Refuge System Water Quality Information System (WQIS)

USGS Publications Warehouse

Chojnacki, Kimberly A.; Vishy, Chad J.; Hinck, Jo Ellen; Finger, Susan E.; Higgins, Michael J.; Kilbride, Kevin

2013-01-01

National Wildlife Refuges may have impaired water quality resulting from historic and current land uses, upstream sources, and aerial pollutant deposition. National Wildlife Refuge staff have limited time available to identify and evaluate potential water quality issues. As a result, water quality–related issues may not be resolved until a problem has already arisen. The National Wildlife Refuge System Water Quality Information System (WQIS) is a relational database developed for use by U.S. Fish and Wildlife Service staff to identify existing water quality issues on refuges in the United States. The WQIS database relies on a geospatial overlay analysis of data layers for ownership, streams and water quality. The WQIS provides summary statistics of 303(d) impaired waters and total maximum daily loads for the National Wildlife Refuge System at the national, regional, and refuge level. The WQIS allows U.S. Fish and Wildlife Service staff to be proactive in addressing water quality issues by identifying and understanding the current extent and nature of 303(d) impaired waters and subsequent total maximum daily loads. Water quality data are updated bi-annually, making it necessary to refresh the WQIS to maintain up-to-date information. This manual outlines the steps necessary to update the data and reports in the WQIS.

To What Extent is Drinking Water Tested in Sub-Saharan Africa? A Comparative Analysis of Regulated Water Quality Monitoring.

PubMed

Peletz, Rachel; Kumpel, Emily; Bonham, Mateyo; Rahman, Zarah; Khush, Ranjiv

2016-03-02

Water quality information is important for guiding water safety management and preventing water-related diseases. To assess the current status of regulated water quality monitoring in sub-Saharan Africa, we evaluated testing programs for fecal contamination in 72 institutions (water suppliers and public health agencies) across 10 countries. Data were collected through written surveys, in-person interviews, and analysis of microbial water quality testing levels. Though most institutions did not achieve the testing levels specified by applicable standards or World Health Organization (WHO) Guidelines, 85% of institutions had conducted some microbial water testing in the previous year. Institutions were more likely to meet testing targets if they were suppliers (as compared to surveillance agencies), served larger populations, operated in urban settings, and had higher water quality budgets (all p < 0.05). Our results indicate that smaller water providers and rural public health offices will require greater attention and additional resources to achieve regulatory compliance for water quality monitoring in sub-Saharan Africa. The cost-effectiveness of water quality monitoring should be improved by the application of risk-based water management approaches. Efforts to strengthen monitoring capacity should pay greater attention to program sustainability and institutional commitment to water safety.

To What Extent is Drinking Water Tested in Sub-Saharan Africa? A Comparative Analysis of Regulated Water Quality Monitoring

PubMed Central

Peletz, Rachel; Kumpel, Emily; Bonham, Mateyo; Rahman, Zarah; Khush, Ranjiv

2016-01-01

Water quality information is important for guiding water safety management and preventing water-related diseases. To assess the current status of regulated water quality monitoring in sub-Saharan Africa, we evaluated testing programs for fecal contamination in 72 institutions (water suppliers and public health agencies) across 10 countries. Data were collected through written surveys, in-person interviews, and analysis of microbial water quality testing levels. Though most institutions did not achieve the testing levels specified by applicable standards or World Health Organization (WHO) Guidelines, 85% of institutions had conducted some microbial water testing in the previous year. Institutions were more likely to meet testing targets if they were suppliers (as compared to surveillance agencies), served larger populations, operated in urban settings, and had higher water quality budgets (all p < 0.05). Our results indicate that smaller water providers and rural public health offices will require greater attention and additional resources to achieve regulatory compliance for water quality monitoring in sub-Saharan Africa. The cost-effectiveness of water quality monitoring should be improved by the application of risk-based water management approaches. Efforts to strengthen monitoring capacity should pay greater attention to program sustainability and institutional commitment to water safety. PMID:26950135

Enhancing drought resilience with conjunctive use and managed aquifer recharge in California and Arizona

USGS Publications Warehouse

Scanlon, Bridget R.; Reedy, Robert C.; Faunt, Claudia; Pool, Donald R.; Uhlman, Kristine;

2016-01-01

Projected longer‐term droughts and intense floods underscore the need to store more water to manage climate extremes. Here we show how depleted aquifers have been used to store water by substituting surface water use for groundwater pumpage (conjunctive use, CU) or recharging groundwater with surface water (Managed Aquifer Recharge, MAR). Unique multi‐decadal monitoring from thousands of wells and regional modeling datasets for the California Central Valley and central Arizona were used to assess CU and MAR. In addition to natural reservoir capacity related to deep water tables, historical groundwater depletion further expanded aquifer storage by ~44 km3 in the Central Valley and by ~100 km3 in Arizona, similar to or exceeding current surface reservoir capacity by up to three times. Local river water and imported surface water, transported through 100s of km of canals, is substituted for groundwater (≤15 km3/yr, CU) or is used to recharge groundwater (MAR, ≤1.5 km3/yr) during wet years shifting to mostly groundwater pumpage during droughts. In the Central Valley, CU and MAR locally reversed historically declining water‐level trends, which contrasts with simulated net regional groundwater depletion. In Arizona, CU and MAR also reversed historically declining groundwater level trends in Active Management Areas. These rising trends contrast with current declining trends in irrigated areas that lack access to surface water to support CU or MAR. Use of depleted aquifers as reservoirs could expand with winter flood irrigation or capturing flood discharges to the Pacific (0 – 1.6 km3/yr, 2000–2014) with additional infrastructure in California. Because flexibility and expanded portfolio options translate to resilience, CU and MAR enhance drought resilience through multi‐year storage, complementing shorter term surface reservoir storage, and facilitating water markets.

Use Of The Operational Air Quality Monitor (AQM) For In-Flight Water Testing Project

NASA Technical Reports Server (NTRS)

Macatangay, Ariel

2014-01-01

A primary requirement for manned spaceflight is Environmental Health which ensures air and water contaminants, acoustic profiles, microbial flora, and radiation exposures within the cabin are maintained to levels needed for crew health and for vehicle system functionality. The reliance on ground analyses of returned samples is a limitation in the current environmental monitoring strategy that will prevent future Exploration missions beyond low-Earth orbit. This proposal attempts to address this shortcoming by advancing in-flight analyses of water and air. Ground analysis of in-flight, air and water samples typically employ vapor-phase analysis by gas chromatography-mass spectrometry (GC-MS) to identify and quantify organic compounds present in the samples. We envision the use of newly-developed direct ionization approaches as the most viable avenue leading towards an integrated analytical platform for the monitoring of water, air, and, potentially bio-samples in the cabin environment. Development of an in-flight instrument capable of analyzing air and water samples would be the logical next step to meeting the environmental monitoring needs of Exploration missions. Currently, the Air Quality Monitor (AQM) on-board ISS provides this specific information for a number of target compounds in the air. However, there is a significant subset of common target compounds between air and water. Naturally, the following question arises, "Can the AQM be used for both air and water quality monitoring?" Previous directorate-level IR&D funding led to the development of a water sample introduction method for mass spectrometry using electrothermal vaporization (ETV). This project will focus on the integration of the ETV with a ground-based AQM. The capabilities of this integrated platform will be evaluated using a subset of toxicologically important compounds.

Seasonal and Interannual Variation of Currents and Water Properties off the Mid-East Coast of Korea

NASA Astrophysics Data System (ADS)

Park, J. H.; Chang, K. I.; Nam, S.

2016-02-01

Since 1999, physical parameters such as current, temperature, and salinity off the mid-east coast of Korea have been continuously observed from the long-term buoy station called `East-Sea Real-time Ocean monitoring Buoy (ESROB)'. Applying harmonic analysis to 6-year-long (2007-2012) depth-averaged current data from the ESROB, a mean seasonal cycle of alongshore currents, characterized by poleward current in average and equatorward current in summer, is extracted which accounts for 5.8% of the variance of 40 hours low-pass filtered currents. In spite of the small variance explained, a robust seasonality of summertime equatorward reversal typifies the low-passed alongshore currents along with low-density water. To reveal the dynamics underlying the seasonal variation, each term of linearized, depth-averaged momentum equations is estimated using the data from ESROB, adjacent tide gauge stations, and serial hydrographic stations. The result indicates that the reversal of alongshore pressure gradient is a major driver of the equatorward reversals in summer. The reanalysis wind product (MERRA) and satellite altimeter-derived sea surface height (AVISO) data show correlated features between positive (negative) wind stress curl and sea surface depression (uplift). Quantitative estimates reveal that the wind-stress curl accounts for 42% of alongshore sea level variation. Summertime low-density water originating from the northern coastal region is a footprint of the buoyancy-driven equatorward current. An interannual variation (anomalies from the mean seasonal cycle) of alongshore currents and its possible driving mechanisms will be discussed.

Arsenic in private drinking water wells: an assessment of jurisdictional regulations and guidelines for risk remediation in North America.

PubMed

Chappells, Heather; Parker, Louise; Fernandez, Conrad V; Conrad, Cathy; Drage, John; O'Toole, Gary; Campbell, Norma; Dummer, Trevor J B

2014-09-01

Arsenic is a known carcinogen found globally in groundwater supplies due to natural geological occurrence. Levels exceeding the internationally recognized safe drinking water standard of 10 μg/L have been found in private drinking water supplies in many parts of Canada and the United States. Emerging epidemiological evidence confirms groundwater arsenic to be a significant health concern, even at the low to moderate levels typically found in this region. These findings, coupled with survey data reporting limited public adherence to testing and treatment guidelines, have prompted calls for improved protective measures for private well users. The purpose of this review is to assess current jurisdictional provisions for private well water protection in areas where arsenic is known to naturally occur in groundwater at elevated levels. Significant limitations in risk management approaches are identified, including inconsistent and uncoordinated risk communication approaches, lack of support mechanisms for routine water testing and limited government resources to check that testing and treatment guidelines are followed. Key action areas are discussed that can help to build regulatory, community and individual capacity for improved protection of private well water supplies and enhancement of public health.

Extensive Liquid Meltwater Storage in Firn Within the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Forster, Richard R.; Box, Jason E.; vandenBroeke, Michael R.; Miege, Clement; Burgess, Evan W.; vanAngelen, Jan H.; Lenaerts, Jan T. M.; Koenig, Lora S.; Paden, John; Lewis, Cameron;

Bulawayo water supplies: Sustainable alternatives for the next decade

NASA Astrophysics Data System (ADS)

Mkandla, Noel; Van der Zaag, Pieter; Sibanda, Peter

Bulawayo is the second largest city in Zimbabwe with a population of nearly one million people. It is located on the watershed of Umzingwane and Gwayi catchments. The former is part of the Limpopo basin, while the latter drains into the Zambezi basin. Bulawayo has a good potential of economic development but has been stymied by lack of sufficient water. The city currently relies on five surface sources in the Umzingwane catchment where it has to compete with evaporation. The well field from the Nyamandlovu aquifer in the Gwayi catchment, which was constructed as an emergency measure during the 1992 drought, is currently not operational. Alternative water supply sources are far and expensive. A multilinear regression model was developed to analyse and quantify the factors affecting water consumption. It was found that per capita water consumption is very low, indicating suppressed demand. Water rationing, tariffs, rainfall, population growth and gross domestic product are the main factors influencing water consumption in Bulawayo. Assuming that these factors will continue to be influential, future water consumption was projected for intensive, regular and slack water demand management. Future water consumption was then compared with the current water supply capacity in order to determine the date by which the next water supply source is required. With slack demand management, the Nyamandlovu well field should have been operational by 2003, while by the year 2007 an additional source of water is required. With intensive demand management and assuming low population growth, current capacities may suffice to satisfy the suppressed demand until the year 2015, by which time Nyamandlovu wells should be operational again. The additional water supply sources that are currently being considered for Bulawayo (namely the Zambezi water pipeline; Gwayi Shangani dam; Mtshabezi dam; Lower Tuli dam; and Glass block dam) were then compared with an alternative water source not yet contemplated, namely drawing groundwater from Umguza, part of the Nyamandlovu aquifer. The paper then provides details of the Umguza alternative, which was designed at pre-feasibility level by Mkandla [Mkandla, N., 2003. Bulawayo water supplies: Umguza well field as a sustainable alternative for the next decade. Unpublished M.Sc. WREM dissertation. University of Zimbabwe, Harare]. All alternative additional water supply sources were compared in terms of their Net Present Values. It was found that Umguza well field is the least-cost alternative to meet additional water demand. The Umguza alternative will be able to satisfy water demand for a period of six to ten years. Thereafter, the second least-cost alternative, namely Gwayi Shangani dam, must be on stream.

Large-scale forcing of the European Slope Current and associated inflows to the North Sea

NASA Astrophysics Data System (ADS)

Marsh, Robert; Haigh, Ivan; Cunningham, Stuart; Inall, Mark; Porter, Marie; Moat, Ben

2017-04-01

Drifters drogued at 50 m in the European Slope Current at the Hebridean shelf break follow a wide range of pathways, indicating highly variable Atlantic inflow to the North Sea. Slope Current pathways, timescales and transports over 1988-2007 are further quantified in an eddy-resolving ocean model hindcast. Particle trajectories calculated with model currents indicate that Slope Current water is largely "recruited" from the eastern subpolar North Atlantic. Observations of absolute dynamic topography and climatological density support theoretical expectations that Slope Current transport is to first order associated with meridional density gradients in the eastern subpolar gyre, which support a geostrophic inflow towards the slope. In the model hindcast, Slope Current transport variability is dominated by abrupt 25-50% reductions of these density gradients over 1996-1998. Concurrent changes in wind forcing, expressed in terms of density gradients, act in the same sense to reduce Slope Current transport. This indicates that coordinated regional changes of buoyancy and wind forcing acted together to reduce Slope Current transport during the 1990s. Particle trajectories further show that 10-40% of Slope Current water is destined for the northern North Sea within 6 months of passing to the west of Scotland, with a clear decline in this Atlantic inflow over 1988-2007. The influence of variable Slope Current transport on the northern North Sea is also expressed in salinity variations. A proxy for Atlantic inflow may be found in sea level records. Variability of Slope Current transport is implicit in mean sea level differences between Lerwick (Shetland) and Torshavn (Faeroes), in both tide gauge records and a longer model hindcast spanning 1958-2013. Potential impacts of this variability on North Sea biogeochemistry and ecosystems, via associated changes in temperature and seasonal stratification, are discussed.

The European Marine Strategy: Noise Monitoring in European Marine Waters from 2014.

PubMed

Dekeling, René; Tasker, Mark; Ainslie, Michael; Andersson, Mathias; André, Michel; Borsani, Fabrizio; Brensing, Karsten; Castellote, Manuel; Dalen, John; Folegot, Thomas; van der Graaf, Sandra; Leaper, Russell; Liebschner, Alexander; Pajala, Jukka; Robinson, Stephen; Sigray, Peter; Sutton, Gerry; Thomsen, Frank; Werner, Stefanie; Wittekind, Dietrich; Young, John V

2016-01-01

The European Marine Strategy Framework Directive requires European member states to develop strategies for their marine waters leading to programs of measures that achieve or maintain good environmental status (GES) in all European seas by 2020. An essential step toward reaching GES is the establishment of monitoring programs, enabling the state of marine waters to be assessed on a regular basis. A register for impulsive noise-generating activities would enable assessment of their cumulative impacts on wide temporal and spatial scales; monitoring of ambient noise would provide essential insight into current levels and any trend in European waters.

 Frequency of hepatitis E and Hepatitis A virus in water sample collected from Faisalabad, Pakistan.

PubMed

Ahmad, Tahir; Anjum, Sadia; Sadaf Zaidi, Najam-us-Sahar; Ali, Amjad; Waqas, Muhammad; Afzal, Muhammad Sohail; Arshad, Najma

2015-01-01

Hepatitis E and Hepatitis A virus both are highly prevalent in Pakistan mainly present as a sporadic disease. The aim of the current study is to isolate and characterized the specific genotype of Hepatitis E virus from water bodies of Faisalabad, Pakistan. Drinking and sewage samples were qualitatively analyzed by using RT-PCR. HEV Genotype 1 strain was recovered from sewage water of Faisalabad. Prevalence of HEV and HAV in sewage water propose the possibility of gradual decline in the protection level of the circulated vaccine in the Pakistani population.

Infantile methemoglobinemia: reexamining the role of drinking water nitrates.

PubMed

Avery, A A

1999-07-01

Ingestion of nitrates in drinking water has long been thought to be a primary cause of acquired infantile methemoglobinemia, often called blue baby syndrome. However, recent research and a review of historical cases offer a more complex picture of the causes of infantile methemoglobinemia. Gastrointestinal infection and inflammation and the ensuing overproduction of nitric oxide may be the cause of many cases of infantile methemoglobinemia previously attributed to drinking water nitrates. If so, current limits on allowable levels of nitrates in drinking water, which are based solely on the health threat of infantile methemoglobinemia, may be unnecessarily strict.

The effect of selenium on spoil suitability as root zone material at Navajo Mine, New Mexico

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

Lane, J.R.; Buchanan, B.A.; Ramsey, T.C.

1995-09-01

The root zone suitability limits for spoil Se at Navajo Mine in northwest New Mexico are currently 0.8 ppm total Se and 0.15 ppm hot-water soluble Se. These criteria were largely developed by the Office of Surface Mining using data from the Northern Great Plains. Applying these values, approximately 23% of the spoil volume and 47% of the spoil area sampled at Navajo Mine from 1985 to December 1993 were determined to be unsuitable as root zone material. Secondary Se accumulator plants (Atriplex canescens) growing in both undisturbed and reclaimed areas were randomly sampled for selenium from 1985 to Decembermore » 1993. In most cases the undisturbed soil and reclaimed spoil at these plant sampling sites were sampled for both total and hot-water soluble Se. Selenium values for Atriplex canescens samples collected on the undisturbed sites averaged 0.64 ppm and ranged from 0.20 ppm to 2.5 ppm. Selenium values for the plants growing on spoil ranged from 0.02 ppm to 7.75 ppm and averaged 1.07 ppm. Total and hot-water Se values for spoil averaged 0.66 ppm and 0.06 ppm respectively, and ranged from 0.0 to 14.2 for total Se and 0.0 ppm to 0.72 ppm for hot-water soluble Se. The plant Se values were poorly correlated to both total and hot-water soluble Se values for both soil and spoil. Therefore, predicting suitable guidelines using normal regression techniques was ineffective. Based on background Se levels in native soils, and levels found on reclaimed areas with Atriplex canescens, it is suggested that a total Se level of 2.0 ppm and a hot-water soluble Se level of 0.25 ppm should be used to represent the suitability limits for Se at Navajo Mine. If these Se values are used, it is estimated that less than 1% of the spoil volume would be unsuitable. This volume of spoil seems to be a more accurate estimate of the amount of spoil with unsuitable levels of Se than the estimated 23% using the current guidelines.« less

Hydrogeology, hydrologic budget, and water chemistry of the Medina Lake area, Texas

USGS Publications Warehouse

Lambert, Rebecca B.; Grimm, Kenneth C.; Lee, Roger W.

2000-01-01

A three-phase study of the Medina Lake area in Texas was done to assess the hydrogeology and hydrology of Medina and Diversion Lakes combined (the lake system) and to determine what fraction of seepage losses from the lake system might enter the regional ground-water-flow system of the Edwards and (or) Trinity aquifers. Phase 1 consisted of revising the geologic framework for the Medina Lake area. Results of field mapping show that the upper member of the Glen Rose Limestone underlies Medina Lake and the intervening stream channel from the outflow of Medina Lake to the midpoint of Diversion Lake, where the Diversion Lake fault intersects Diversion Lake. A thin sequence of strata consisting primarily of the basal nodular and dolomitic members of the Kainer Formation of the Edwards Group, is present in the southern part of the study area. On the southern side of Medina Lake, the contact between the upper member of the Glen Rose Limestone and the basal nodular member is approximately 1,000 feet above mean sea level, and the contact between the basal nodular member and the dolomitic member is approximately 1,050 feet above mean sea level. The most porous and permeable part of the basal nodular member is about 1,045 feet above mean sea level. At these altitudes, Medina Lake is in hydrologic connection with rocks in the Edwards aquifer recharge zone, and Medina Lake appears to lose more water to the ground-water system along this bedding plane contact. Hydrologic budgets calculated during phase 2 for Medina Lake, Diversion Lake, and Medina/Diversion Lakes combined indicate that: (1) losses from Medina and Diversion Lakes can be quantified; (2) a portion of those losses are entering the Edwards aquifer; and (3) losses to the Trinity aquifer in the Medina Lake area are minimal and within the error of the hydrologic budgets. Hydrologic budgets based on streamflow, precipitation, evaporation, and change in lake storage were used to quantify losses (recharge) to the ground-water system from Medina Lake, Diversion Lake, and Medina/Diversion Lakes combined during October 1995–September 1996. Water losses from Medina Lake to the Edwards/Trinity aquifers ranged from -14.0 to 135 acre-feet per day; Diversion Lake ranged from -1.2 to 93.1 acre-feet per day; and Medina/Diversion Lakes combined ranged from 36.1 to 119 acre-feet per day.Monthly average recharge during December 1995–July 1996 was estimated using an alternative method developed during this study (current study method) and compared to monthly average recharge during December 1995–July 1996 estimated using the existing USGS method and the Trans-Texas method. Recharge to the Edwards aquifer estimated using the current study method was about 69 and 73 percent of the recharge estimated using the USGS and Trans-Texas methods, respectively. The USGS and Trans-Texas methods overestimated recharge from Medina Lake compared to the recharge estimated with the current study method when Medina Lake stage was between about 1,027 and 1,032 feet above mean sea level and underestimated recharge from Medina Lake when lake stage was between about 1,036 and 1,045 feet above mean sea level. The USGS and Trans-Texas methods underestimated recharge from Diversion Lake compared to the recharge estimated with the current study method when Diversion Lake stage was greater than 913 feet above mean sea level and overestimated recharge from Diversion Lake when lake stage was less than 913 feet above mean sea level.The water quality of Medina Lake and Medina River and in selected wells and springs in the Edwards and Trinity aquifers was characterized during phase 3 of the study. Environmental isotope analyses and geochemical modeling also were used to determine where water losses from the lake system might be entering the ground-water-flow system. Isotopic ratios of deuterium, oxygen, and strontium were analyzed in selected surface-water, lake-water, and ground-water samples to trace the isotopic “signature” of the lake water as it mixes with the ground water and to determine the fraction of lake water and ground water in selected Edwards aquifer wells. Isotopic data and geochemical modeling were used to show that lake water is moving into the Edwards aquifer in two fault blocks in the eastern Medina storage unit. One fault block is bounded on the north by the Vandenburg School fault and on the south by the Haby Crossing fault, and the second fault block is bounded on the north by the Diversion Lake fault and on the south by the Haby Crossing fault. In selected Edwards aquifer wells located southwest of Medina Lake and west of Diversion Lake, the proportion of lake water ranged from about 10 to 45 percent. Geochemical modeling using NETPATH confirms the degree of mixing between lake water and aquifer water shown by the isotopes.

TRIHALOMETHANE LEVELS AND SEMEN QUALITY

EPA Science Inventory

Trihalomethanes (THMs) are common byproducts of chlorinating drinking water. The effects of disinfection byproducts on semen quality have not yet been studied in humans, despite animal studies linking exposure to sperm abnormalities. We are currently analyzing the relationship of...

Wave-current induced erosion of cohesive riverbanks in northern Manitoba, Canada

NASA Astrophysics Data System (ADS)

Kimiaghalam, N.; Clark, S.; Ahmari, H.; Hunt, J.

2015-03-01

The field of cohesive soil erosion is still not fully understood, in large part due to the many soil parameters that affect cohesive soil erodibility. This study is focused on two channels, 2-Mile and 8-Mile channels in northern Manitoba, Canada, that were built to connect Lake Winnipeg with Playgreen Lake and Playgreen Lake with Kiskikittogisu Lake, respectively. The banks of the channels consist of clay rich soils and alluvial deposits of layered clay, silts and sands. The study of erosion at the sites is further complicated because the flow-induced erosion is combined with the effects of significant wave action due to the large fetch length on the adjacent lakes, particularly Lake Winnipeg that is the seventh largest lake in North America. The study included three main components: field measurements, laboratory experiments and numerical modelling. Field measurements consisted of soil sampling from the banks and bed of the channels, current measurements and water sampling. Grab soil samples were used to measure the essential physical and electrochemical properties of the riverbanks, and standard ASTM Shelby tube samples were used to estimate the critical shear stress and erodibility of the soil samples using an erosion measurement device (EMD). Water samples were taken to estimate the sediment concentration profile and also to monitor changes in sediment concentration along the channels over time. An Acoustic Doppler Current Profiler (ADCP) was used to collect bathymetry and current data, and two water level gauges have been installed to record water levels at the entrance and outlet of the channels. The MIKE 21 NSW model was used to simulate waves using historical winds and measured bathymetry of the channels and lakes. Finally, results from the wave numerical model, laboratory tests and current measurement were used to estimate the effect of each component on erodibility of the cohesive banks.

Efficient Electrocatalytic Water Oxidation at Neutral and High pH by Adventitious Nickel at Nanomolar Concentrations.

PubMed

Roger, Isolda; Symes, Mark D

2015-11-04

Electrolytic water oxidation using earth-abundant elements is a key challenge in the quest to develop cheap, large surface area arrays for solar-to-hydrogen conversion. There have been numerous studies in this area in recent years, but there remains an imperative to demonstrate that the current densities reported are indeed due to the species under consideration and not due to the presence of adventitious (yet possibly highly active) contaminants at low levels. Herein, we show that adventitious nickel at concentrations as low as 17 nM can act as a water oxidation catalyst in mildly basic aqueous solutions, achieving stable (tens of hours) current densities of 1 mA cm(-2) at overpotentials as low as 540 mV at pH 9.2 and 400 mV at pH 13. This nickel was not added to the electrolysis baths deliberately, but it was found to be present in the electrolytes as an impurity by ICP-MS. The presence of nickel on anodes from extended-time bulk electrolysis experiments was confirmed by XPS. In showing that such low levels of nickel can perform water oxidation at overpotentials comparable to many recently reported water oxidation catalysts, this work serves to raise the burden of proof required of new materials in this field: contamination by adventitious metal ions at trace loadings must be excluded as a possible cause of any observed water oxidation activity.

Involved, United, and Efficacious: Could Self-Affirmation Be the Solution to California's Drought?

PubMed

Walter, Nathan; Demetriades, Stefanie Z; Murphy, Sheila T

2017-09-01

Self-affirmation theory posits that thoughts and actions that affirm an important aspect of the self-concept can make people more susceptible to change by casting their self in a positive light. Whereas much of the current literature has been restricted to individual-level concerns, the current study provides longitudinal evidence for behavioral outcomes in the context of the California drought, advancing our theoretical knowledge regarding the underlying processes that lead self-affirmed individuals to address societal risks and collective concerns. The results of a three-wave experimental study (N = 91) indicated that relative to nonaffirmed counterparts, self-affirmed participants reported on higher levels of support for water conservation policies, as well as on reduction of water use that endured for 30 days following the self-affirming manipulation. In both cases, the effects were mediated by collective-efficacy but not by self-efficacy. Relevant explanations are considered and practical and theoretical implications are discussed.

Portrait of a Warming Ocean and Rising Sea Levels: Trend of Sea Level Change 1993-2008

NASA Technical Reports Server (NTRS)

2008-01-01

Warming water and melting land ice have raised global mean sea level 4.5 centimeters (1.7 inches) from 1993 to 2008. But the rise is by no means uniform. This image, created with sea surface height data from the Topex/Poseidon and Jason-1 satellites, shows exactly where sea level has changed during this time and how quickly these changes have occurred.

It's also a road map showing where the ocean currently stores the growing amount of heat it is absorbing from Earth's atmosphere and the heat it receives directly from the Sun. The warmer the water, the higher the sea surface rises. The location of heat in the ocean and its movement around the globe play a pivotal role in Earth's climate.

Light blue indicates areas in which sea level has remained relatively constant since 1993. White, red, and yellow are regions where sea levels have risen the most rapidly up to 10 millimeters per year and which contain the most heat. Green areas have also risen, but more moderately. Purple and dark blue show where sea levels have dropped, due to cooler water.

The dramatic variation in sea surface heights and heat content across the ocean are due to winds, currents and long-term changes in patterns of circulation. From 1993 to 2008, the largest area of rapidly rising sea levels and the greatest concentration of heat has been in the Pacific, which now shows the characteristics of the Pacific Decadal Oscillation (PDO), a feature that can last 10 to 20 years or even longer.

In this 'cool' phase, the PDO appears as a horseshoe-shaped pattern of warm water in the Western Pacific reaching from the far north to the Southern Ocean enclosing a large wedge of cool water with low sea surface heights in the eastern Pacific. This ocean/climate phenomenon may be caused by wind-driven Rossby waves. Thousands of kilometers long, these waves move from east to west on either side of the equator changing the distribution of water mass and heat.

This image of sea level trend also reveals a significant area of rising sea levels in the North Atlantic where sea levels are usually low. This large pool of rapidly rising warm water is evidence of a major change in ocean circulation. It signals a slow down in the sub-polar gyre, a counter-clockwise system of currents that loop between Ireland, Greenland and Newfoundland.

Such a change could have an impact on climate since the sub-polar gyre may be connected in some way to the nearby global thermohaline circulation, commonly known as the global conveyor belt. This is the slow-moving circulation in which water sinks in the North Atlantic at different locations around the sub-polar gyre, spreads south, travels around the globe, and slowly up-wells to the surface before returning around the southern tip of Africa. Then it winds its way through the surface currents in the Atlantic and eventually comes back to the North Atlantic.

It is unclear if the weakening of the North Atlantic sub-polar gyre is part of a natural cycle or related to global warming.

This image was made possible by the detailed record of sea surface height measurements begun by Topex/Poseidon and continued by Jason-1. The recently launched Ocean Surface Topography Mission on the Jason-2 satellite (OSTM/Jason-2) will soon take over this responsibility from Jason-1. The older satellite will move alongside OSTM/Jason-2 and continue to measure sea surface height on an adjacent ground track for as long as it is in good health.

Topex/Poseidon and Jason-1 are joint missions of NASA and the French space agency, CNES. OSTM/Jason-2 is collaboration between NASA; the National Oceanic and Atmospheric Administration; CNES; and the European Organisation for the Exploitation of Meteorological Satellites. JPL manages the U.S. portion of the missions for NASA's Science Mission Directorate, Washington, D.C.

Human Health Screening and Public Health Significance of ...

EPA Pesticide Factsheets

The source water and treated drinking water from twenty five drinking water treatment plants (DWTPs) across the United States were sampled in 2010 – 2012. Samples were analyzed for 247 contaminants using 15 chemical and microbiological methods. Most of these contaminants are not regulated currently either in drinking water or in discharges to ambient water by the United States Environmental Protection Agency (EPA) or other U.S. regulatory agencies. This analysis shows that there is little public health concern for most of the contaminants detected in treated water from the 25 DWTPs participating in this study. For vanadium, the calculated MOE was less than the screening MOE in two DWTPs. Additional study, for example a national survey may be needed to determine the number of people ingesting vanadium above a level of concern. In addition, the concentrations of lithium found in treated water from several DWTPs are within the range previous research has suggested to have a human health effect. Additional investigation of this issue may also be appropriate. Finally, new toxicological data suggests that exposure to manganese at levels in public water supplies may present a public health concern which may warrant a more robust assessment of this information. This paper provides a screening-level human health risk assessment using the margin of exposure of exposure approach, of contaminants of emerging concern detected in drinking water. As far as we are a

National Water-Quality Assessment Program; the Allegheny-Monongahela River Basin

USGS Publications Warehouse

McAuley, Steven D.

1995-01-01

In 1991, the U.S. Geological Survey (USGS) began a National Water-Quality Assessment (NAWQA) program. The three major objectives of the NAWQA program are to provide a consistent description of current water-quality conditions for a large part of the Nation's water resources, define long-term trends in water quality, and identify, describe, and explain the major factors that affect water-quality conditions and trends. The program produces water-quality information that is useful to policy makers and managers at the National, State, and local levels.The program will be implemented through 60 separate investigations of river basins and aquifer systems called study units. These study-unit investigations will be conducted at the State and local level and will form the foundation on which national- and regional-level assessments are based. The 60 study units are hydrologic systems that include parts of most major river basins and aquifer systems. The study-unit areas range from 1,000 to more than 60,000 square miles and include about 60 to 70 percent of the Nation's water use and population served by public water supplies. Twenty studyunit investigations were started in 1991, 20 started in 1994, and 20 more are planned to start in 1997. The Allegheny-Monongahela River Basin was selected to begin assessment activities as a NAWQA study unit in 1994. The study team will work from the office of the USGS in Pittsburgh, Pa.

Exchanges of Water between the Upper Floridan Aquifer and the Lower Suwannee and Lower Santa Fe Rivers, Florida

USGS Publications Warehouse

Grubbs, J.W.; Crandall, C.A.

2007-01-01

Exchanges of water between the Upper Floridan aquifer and the Lower Suwannee River were evaluated using historic and current hydrologic data from the Lower Suwannee River Basin and adjacent areas that contribute ground-water flow to the lowest 76 miles of the Suwannee River and the lowest 28 miles of the Santa Fe River. These and other data were also used to develop a computer model that simulated the movement of water in the aquifer and river, and surface- and ground-water exchanges between these systems over a range of hydrologic conditions and a set of hypothetical water-use scenarios. Long-term data indicate that at least 15 percent of the average annual flow in the Suwannee River near Wilcox (at river mile 36) is derived from ground-water discharge to the Lower Suwannee and Lower Santa Fe Rivers. Model simulations of ground-water flow to this reach during water years 1998 and 1999 were similar to these model-independent estimates and indicated that ground-water discharge accounted for about 12 percent of the flow in the Lower Suwannee River during this time period. The simulated average ground-water discharge to the Lower Suwannee River downstream from the mouth of the Santa Fe River was about 2,000 cubic feet per second during water years 1998 and 1999. Simulated monthly average ground-water discharge rates to this reach ranged from about 1,500 to 3,200 cubic feet per second. These temporal variations in ground-water discharge were associated with climatic phenomena, including periods of strong influence by El Ni?o-associated flooding, and La Ni?a-associated drought. These variations showed a relatively consistent pattern in which the lowest rates of ground-water inflow occurred during periods of peak flood levels (when river levels rose faster than ground-water levels) and after periods of extended droughts (when ground-water storage was depleted). Conversely, the highest rates of ground-water inflow typically occurred during periods of receding levels that followed peak river levels.

Fluctuations of sediments-related optical parameters on a megatidal beach in the Eastern English Channel

NASA Astrophysics Data System (ADS)

Xing, Q.; Schmitt, F.; Loisel, H.

2009-04-01

To investigate the influence of turbulence coupled with waves and tides on the re-suspension of sediments, a 4-hour field experiment was conducted on a surf-zone beach near Wimereux, France where is at the Eastern English Channel and characterized by a semi-diurnal megatide (spring tidal range > 8 m). A sensor cluster was fixed 1.5 m above the sea bed when the tidal level was low. The parameters of the particle scattering coefficient and the optical attenuation coefficient were measured as a surrogate of the suspended sediments concentration (SSC), and the water temperature, the pressure, the horizontal 2-D velocity and so on, were also simultaneously measured in a continuous mode at a frequency of 1 Hz. The parameter of pressure was used for monitoring the water level and estimating the variation of surface wave heights by removing the local averages of time series, and the pressure time series show that the experiment started with a water level of about 3.7 m at 10 o'clock and ended with 4.5 m at 14 o'clock, and that the water level reached the highest at about 12 o'clock. The time series of current direction indicate that there was a steady along-coast current with a direction of 218 degrees when the water level almost reached the largest of 6 m, i.e., when the sensors were 4.5 m under the water surface. The particle scattering coefficient and the optical attenuation coefficient exhibit a similar fluctuating trend with a correlation coefficient of 0.85 between them. Although there is a time lag of about 1000 s, a relation between the optical parameters and the square of U is observed, i.e., SSC is a function of U, where U is the vector product of the along-shore and cross-shore velocities (v and u). The cross-shore velocity u fluctuates roughly with a mean of zero, and its variation decreases exponentially with the increase of water level, which is consistent with the common sense that wave orbital motions decrease exponentially with the water depth; the variation of v is slightly different to that of u, and the mean of fluctuations changes against the occurrence of along-coast current. Power spectral analysis on the basis of Fast Fourier Transform (FFT) is used to study their scaling behaviors in an energy (E(f)) ~ frequency (f) function of log(E(f)) ~ -p log(f). Temperature fluctuations exhibit to be corresponding to a passive scalar turbulence, p=1.79. When f < 0.003Hz, the values of p with the fluctuations of v and u are between 5/3 and 3, and more close to 3, which may suggest a main component of wave orbital motions in the mixed behavior with turbulence. Particle scattering coefficients and water attenuation coefficients exhibit a similar scaling behavior to each other, and when f < 0.003Hz, the values of p are close to 3 and a little larger than it, which also suggests the role of wave orbital motions in the re-suspension of sediments. In this experiments, a water volume of tens to one hundred cubic centimeters were monitored for velocity measurement. However, a finer spatial resolution may be more suitable for the observation of turbulence as well as the sediments-related optical parameters.

Water gate array for current flow or tidal movement pneumatic harnessing system

DOEpatents

Gorlov, Alexander M.

1991-01-01

The invention, which provides a system for harnessing power from current flow or tidal movement in a body of water, comprises first and second hydro-pneumatic chambers each having ingress and egress below the water surface near the river or ocean floor and water gates operative to open or seal the ports to the passage of water. In an exemplary embodiment, the gates are sychronized by shafts so that the ingress ports of each chamber are connected to the egress ports of each other chamber. Thus, one set of gates is closed, while the other is open, thereby allowing water to flow into one chamber and build air pressure therein and allowing water to flow out of the other chamber and create a partial vacuum therein. A pipe connects the chambers, and an air turbine harnesses the air movement within the pipe. When water levels are equilibrated, the open set of gates is closed by a counterweight, and the other set is allowed to open by natural force of the water differential. The water gates may be comprised of a plurality of louvers which are ganged for simultaneous opening and closing. The system is designed to operate with air turbines or other pneumatic devices. Its design minimizes construction cost and environmental impact, yet provides a clean renewable energy source.

Real Time Monitoring System of Pollution Waste on Musi River Using Support Vector Machine (SVM) Method

NASA Astrophysics Data System (ADS)

Fachrurrozi, Muhammad; Saparudin; Erwin

2017-04-01

Real-time Monitoring and early detection system which measures the quality standard of waste in Musi River, Palembang, Indonesia is a system for determining air and water pollution level. This system was designed in order to create an integrated monitoring system and provide real time information that can be read. It is designed to measure acidity and water turbidity polluted by industrial waste, as well as to show and provide conditional data integrated in one system. This system consists of inputting and processing the data, and giving output based on processed data. Turbidity, substances, and pH sensor is used as a detector that produce analog electrical direct current voltage (DC). Early detection system works by determining the value of the ammonia threshold, acidity, and turbidity level of water in Musi River. The results is then presented based on the level group pollution by the Support Vector Machine classification method.

Bootstrap position analysis for forecasting low flow frequency

USGS Publications Warehouse

Tasker, Gary D.; Dunne, P.

1997-01-01

A method of random resampling of residuals from stochastic models is used to generate a large number of 12-month-long traces of natural monthly runoff to be used in a position analysis model for a water-supply storage and delivery system. Position analysis uses the traces to forecast the likelihood of specified outcomes such as reservoir levels falling below a specified level or streamflows falling below statutory passing flows conditioned on the current reservoir levels and streamflows. The advantages of this resampling scheme, called bootstrap position analysis, are that it does not rely on the unverifiable assumption of normality, fewer parameters need to be estimated directly from the data, and accounting for parameter uncertainty is easily done. For a given set of operating rules and water-use requirements for a system, water managers can use such a model as a decision-making tool to evaluate different operating rules. ?? ASCE,.

Preliminary investigation of the effects of sea-level rise on groundwater levels in New Haven, Connecticut

USGS Publications Warehouse

Bjerklie, David M.; Mullaney, John R.; Stone, Janet R.; Skinner, Brian J.; Ramlow, Matthew A.

2012-01-01

Global sea level rose about 0.56 feet (ft) (170 millimeters (mm)) during the 20th century. Since the 1960s, sea level has risen at Bridgeport, Connecticut, about 0.38 ft (115 mm), at a rate of 0.008 ft (2.56 mm + or - 0.58 mm) per year. With regional subsidence, and with predicted global climate change, sea level is expected to continue to rise along the northeast coast of the United States through the 21st century. Increasing sea levels will cause groundwater levels in coastal areas to rise in order to adjust to the new conditions. Some regional climate models predict wetter climate in the northeastern United States under some scenarios. Scenarios for the resulting higher groundwater levels have the potential to inundate underground infrastructure in lowlying coastal cities. New Haven is a coastal city in Connecticut surrounded and bisected by tidally affected waters. Monitoring of water levels in wells in New Haven from August 2009 to July 2010 indicates the complex effects of urban influence on groundwater levels. The response of groundwater levels to recharge and season varied considerably from well to well. Groundwater temperatures varied seasonally, but were warmer than what was typical for Connecticut, and they seem to reflect the influence of the urban setting, including the effects of conduits for underground utilities. Specific conductance was elevated in many of the wells, indicating the influence of urban activities or seawater in Long Island Sound. A preliminary steady-state model of groundwater flow for part of New Haven was constructed using MODFLOW to simulate current groundwater levels (2009-2010) and future groundwater levels based on scenarios with a rise of 3 ft (0.91 meters (m)) in sea level, which is predicted for the end of the 21st century. An additional simulation was run assuming a 3-ft rise in sea level combined with a 12-percent increase in groundwater recharge. The model was constructed from existing hydrogeologic information for the New Haven area and from new information on groundwater levels collected during October 2009-June 2010. For the scenario with a 3-ft rise in sea level and no increase in recharge, simulated groundwater levels near the coast rose 3 ft; this increased water level tapered off toward a discharge area at the only nontidal stream in the study area. Simulated stream discharge increased at the nontidal stream because of the increased gradient. Although groundwater levels rose, the simulated difference between the groundwater levels in the aquifer and the increased sea level declined, indicating that the depth to the interface between freshwater and saltwater may possibly decline. Simulated water levels were affected by rise in sea level even in areas where the water table was at 17-24 ft (5.2-7.3 m) above current (2011) sea level. For the scenario with increased recharge, simulated groundwater levels were as much as an additional foot higher at some locations in the study area. The results of this preliminary investigation indicate that groundwater levels in coastal areas can be expected to rise and may rise higher if groundwater recharge also increases. This finding has implications for the disposal of stormwater through infiltration, a low-impact development practice designed to improve water quality and reduce overland peak discharge. Other implications include increased risk of basement flooding and increased groundwater seepage into underground sewer pipes and utility corridors in some areas. These implications will present engineering challenges to New Haven and Yale University. The preliminary model developed for this study can be the starting point for further simulation of future alternative scenarios for sea-level rise and recharge. Further simulations could identify those areas of New Haven where infrastructure may be at greatest risk from rising levels of groundwater. The simulations described in this report have limitations due to the preliminary scope of the work. Approaches to improve simulations include but are not limited to incorporating: * The variable density of seawater into the model in order to understand the current and future location of the interface between freshwater and saltwater; * Collection of additional data in order to better resolve temporal and spatial patterns in water levels in the aquifer; * Improved estimates of recharge through direct and indirect measurements of freshwater discharge from the study area; and * Transient simulations for greater understanding of the amount of time required for water levels and the position of the interface between freshwater and saltwater to adjust to changes in sea level and recharge.

Hydrogeology and trichloroethene contamination in the sea-level aquifer beneath the Logistics Center, Fort Lewis, Washington

USGS Publications Warehouse

Dinicola, Richard S.

2005-01-01

The U.S. Army disposed of waste trichloroethene (TCE) and other materials in the East Gate Disposal Yard near the Logistics Center on Fort Lewis, Washington, from the 1940s to the early 1970s. As a result, ground water contaminated with primarily TCE extends more than 3 miles downgradient from the East Gate Disposal Yard. The site is underlain by a complex and heterogeneous sequence of glacial and non-glacial deposits that have been broadly categorized into an upper and a lower aquifer (the latter referred to as the sea-level aquifer). TCE contamination was detected in both aquifers. This report describes an investigation by the U.S. Geological Survey (USGS) of the source, migration, and attenuation of TCE in the sea-level aquifer. A refined conceptual model for ground-water flow and contaminant migration into and through the sea-level aquifer was developed in large part from interpretation of environmental tracer data. The tracers used included stable isotopes of oxygen (18O), hydrogen (2H), and carbon (13C); the radioactive hydrogen isotope tritium (3H); common ions and redox-related analytes; chlorofluorocarbons; and sulfur hexafluoride. Tracer and TCE concentrations were determined for samples collected by the USGS from 37 wells and two surface-water sites in American Lake during 1999-2000. Ground-water levels were measured by the USGS in more than 40 wells during 2000-01, and were combined with measurements by the U.S. Army and others to create potentiometric-surface maps. Localized ground-water flow features were identified that are of particular relevance to the migration of TCE in the study area. A ridge of ground water beneath American Lake diverts the flow of TCE-contaminated ground water in the sea-level aquifer to the west around the southern end of the lake. Tracer data provided clear evidence that American Lake is a significant source of recharge to the sea-level aquifer that has created that ridge of ground water. High ground-water altitudes at locations north and northeast of the Logistics Center combined with the ridge beneath American Lake prevent TCE contaminated water beneath the Logistics Center from migrating toward municipal water-supply wells northeast of the site. The 1999-2000 TCE concentrations measured by the USGS at older wells screened in the sea-level aquifer were similar to those measured since 1995, but the known downgradient extent of the TCE contamination expanded nearly 2 miles after the Army installed and sampled new wells during 2003-04. Concentrations of TCE in the sea-level aquifer were consistently highest in the upper part of the aquifer throughout the plume, although TCE has spread throughout much of the thickness of the aquifer in the downgradient portions of the plume. Environmental tracer data indicated that the primary pathway for contaminant migration into the sea-level aquifer is through the previously identified confining unit window, an area where the predominately fine-grained confining unit is relatively coarse grained and more permeable. Other less substantial pathways for contaminant migration also were identified near the East Gate Disposal Yard and the I-5 pump-and-treat facilities. Those areas are near active pumping wells and ground-water reintroduction facilities, but there is no evidence that the contaminant migration was caused or enhanced by those activities. Within the sea-level aquifer, TCE concentrations continue to migrate westward in the flow field strongly influenced by ground-water recharge from American Lake. Historical data are not available to definitively determine if the 5-?g/L leading edge of the current TCE plume is stable or if it is still moving downgradient. However, an evaluation of the available data combined with TCE traveltime estimates indicates that the peak TCE concentrations in the sea-level aquifer may have not yet reached the wells near the currently defined leading edge of the plume. Hypothetically, the 5-?g/L leading edge

Changes of freshwater-lens thickness in basaltic island aquifers overlain by thick coastal sediments

USGS Publications Warehouse

Rotzoll, Kolja; Oki, Delwyn S.; El-Kadi, Aly I.

2010-01-01

Freshwater-lens thickness and long-term changes in freshwater volume in coastal aquifers are commonly assessed through repeated measurement of salinity profiles from monitor wells that penetrate into underlying salt water. In Hawaii, the thickest measured freshwater lens is currently 262 m in dike-free, volcanic-rock aquifers that are overlain by thick coastal sediments. The midpoint depth (depth where salinity is 50% salt water) between freshwater and salt water can serve as an indicator for freshwater thickness. Most measured midpoints have risen over the past 40 years, indicating a shrinking lens. The mean rate of rise of the midpoint from 1999–2009 varied locally, with faster rates in highly developed areas (1.0 m/year) and slower rates in less developed areas (0.5 m/year). The thinning of the freshwater lenses is the result of long-term groundwater withdrawal and reduced recharge. Freshwater/salt-water interface locations predicted from measured water levels and the Ghyben-Herzberg principle may be deeper than measured midpoints during some periods and shallower during other periods, although depths may differ up to 100 m in some cases. Moreover, changes in the midpoint are slower than changes in water level. Thus, water levels may not be a reliable indicator of the amount of freshwater in a coastal aquifer.

Level 1 Water-Quality Inventory of Baseline Levels of Pesticides in Urban Creeks - Golden Gate National Recreation Area and the Presidio of San Francisco, California

USGS Publications Warehouse

Hladik, Michelle; Orlando, James L.

2008-01-01

To characterize baseline water-quality levels of pesticides in Golden Gate National Recreation Area and the Presidio of San Francisco, the U.S. Geological Survey collected and analyzed surface-water and bed-sediment samples at 10 creeks during February, April, and July 2006. Pesticide data were obtained using previously developed methods. Samples from sites in the Presidio were analyzed only for pyrethroid insecticides, whereas the remaining samples were analyzed for pyrethroids and additional current and historical-use pesticides. Pesticide concentrations were low in both the water (below 30 ng/L) and sediment (below 3 ng/g). The pyrethroid bifenthrin was detected in water samples from two sites at concentrations below 2 ng/L. Other compounds detected in water included the herbicides dacthal (DCPA) and prometryn, the insecticide fipronil, the insecticide degradates p,p'-DDE and fipronil sulfone, and the fungicides cyproconazole, myclobutanil and tetraconazole. The only pesticides detected in the sediment samples were p,p'-DDT and its degradates (p,p'-DDD and p,p'-DDE). Pesticide information from the samples collected can provide a reference point for future sampling and can help National Park Service managers assess the water quality of the urban creeks.

Flood-inundation maps for the Saddle River in Ho-Ho-Kus Borough, the Village of Ridgewood, and Paramus Borough, New Jersey, 2013

USGS Publications Warehouse

Watson, Kara M.; Niemoczynski, Michal J.

2014-01-01

Digital flood-inundation maps for a 5.4-mile reach of the Saddle River in New Jersey from Hollywood Avenue in Ho-Ho-Kus Borough downstream through the Village of Ridgewood and Paramus Borough to the confluence with Hohokus Brook in the Village of Ridgewood were created by the U.S. Geological Survey (USGS) in cooperation with the New Jersey Department of Environmental Protection (NJDEP). The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Saddle River at Ridgewood, New Jersey (station 01390500). Current conditions for estimating near real-time areas of inundation using USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/nwis/uv?site_no=01390500 or at the National Weather Services (NWS) Advanced Hydrologic Prediction Service (AHPS) at http://water.weather.gov/ahps2/hydrograph.php?wfo=okx&gage=rwdn4. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relation (March 11, 2011) at the USGS streamgage 01390500, Saddle River at Ridgewood, New Jersey. The hydraulic model was then used to compute 10 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum, North American Vertical Datum of 1988 (NAVD 88), and ranging from 5 ft, the NWS “action and minor flood stage”, to 14 ft, which is the maximum extent of the stage-discharge rating and 0.6 ft higher than the highest recorded water level at the streamgage. The simulated water-surface profiles were then combined with a geographic information system 3-meter (9.84-ft) digital elevation model derived from Light Detection and Ranging (lidar) data in order to delineate the area flooded at each water level. The availability of these maps along with information on the Internet regarding current stage from the USGS streamgage provides emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures as well as for post-flood recovery efforts.

Flood-inundation maps for the Elkhart River at Goshen, Indiana

USGS Publications Warehouse

Strauch, Kellan R.

2013-01-01

The U.S. Geological Survey (USGS), in cooperation with the Indiana Office of Community and Rural Affairs, created digital flood-inundation maps for an 8.3-mile reach of the Elkhart River at Goshen, Indiana, extending from downstream of the Goshen Dam to downstream from County Road 17. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to nine selected water levels (stages) at the USGS streamgage at Elkhart River at Goshen (station number 04100500). Current conditions for the USGS streamgages in Indiana may be obtained on the Internet at http://waterdata.usgs.gov/. In addition, stream stage data have been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that are often colocated with USGS streamgages. NWS-forecasted peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated using the most current stage-discharge relation at the Elkhart River at Goshen streamgage. The hydraulic model was then used to compute nine water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from approximately bankfull (5 ft) to greater than the highest recorded water level (13 ft). The simulated water-surface profiles were then combined with a geographic information system (GIS) digital-elevation model (DEM), derived from Light Detection and Ranging (LiDAR) data having a 0.37-ft vertical accuracy and 3.9-ft horizontal resolution in order to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from USGS streamgages and forecasted stream stages from the NWS, provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for postflood recovery efforts.

A comparison of three methods to estimate evapotranspiration in two contrasting loblolly pine plantations: age-related changes in water use and drought sensitivity of evapotranspiration components

Treesearch

Jean-Christophe Domec; Ge Sun; Asko Noormets; Michael J. Gavazzi; Emrys A. Treasure; Erika Cohen; Jennifer J. Swenson; Steve G. McNulty; John S. King

2012-01-01

Increasing variability of rainfall patterns requires detailed understanding of the pathways of water loss from ecosystems to optimize carbon uptake and management choices. In the current study we characterized the usability of three alternative methods of different rigor for quantifying stand-level evapotranspiration (ET), partitioned ET into tree transpiration (T),...

Sensitivity of GRACE-derived estimates of groundwater-level changes in southern Ontario, Canada

NASA Astrophysics Data System (ADS)

Hachborn, Ellen; Berg, Aaron; Levison, Jana; Ambadan, Jaison Thomas

2017-12-01

Amidst changing climates, understanding the world's water resources is of increasing importance. In Ontario, Canada, low water conditions are currently assessed using only precipitation and watershed-based stream gauges by the Conservation Authorities in Ontario and the Ministry of Natural Resources and Forestry. Regional groundwater-storage changes in Ontario are not currently measured using satellite data by research institutes. In this study, contributions from the Gravity Recovery and Climate Experiment (GRACE) data are compared to a hydrogeological database covering southern Ontario from 2003 to 2013, to determine the suitability of GRACE total water storage estimates for monitoring groundwater storage in this location. Terrestrial water storage data from GRACE were used to determine monthly groundwater storage (GWS) anomaly values. GWS values were also determined by multiplying groundwater-level elevations (from the Provincial Groundwater Monitoring Network wells) by specific yield. Comparisons of GRACE-derived GWS to well-based GWS data determined that GRACE is sufficiently sensitive to obtain a meaningful signal in southern Ontario. Results show that GWS values produced by GRACE are useful for identifying regional changes in groundwater storage in areas with limited available hydrogeological characterization data. Results also indicate that GRACE may have an ability to forecast changes in groundwater storage, which will become useful when monitoring climate shifts in the near future.

Water-Level Changes in Aquifers of the Atlantic Coastal Plain, Predevelopment to 2000

USGS Publications Warehouse

dePaul, Vincent T.; Rice, Donald E.; Zapecza, Otto S.

2008-01-01

The Atlantic Coastal Plain aquifer system, which underlies a large part of the east coast of the United States, is an important source of water for more than 20 million people. As the population of the region increases, further demand is being placed on those ground-water resources. To define areas of past and current declines in ground-water levels, as well as to document changes in those levels, historical water-level data from more than 4,000 wells completed in 13 regional aquifers in the Atlantic Coastal Plain were examined. From predevelopment to 1980, substantial water-level declines occurred in many areas of the Atlantic Coastal Plain. Regional variability in water-level change in the confined aquifers of the Atlantic Coastal Plain resulted from regional differences in aquifer properties and patterns of ground-water withdrawals. Within the Northern Atlantic Coastal Plain, declines of more than 100 ft were observed in New Jersey, Delaware, Maryland, Virginia, and North Carolina. Regional declines in water levels were most widespread in the deeper aquifers that were most effectively confined?the Upper, Middle, and Lower Potomac aquifers. Within these aquifers, water levels had declined up to 200 ft in southern Virginia and to more than 100 ft in New Jersey, Delaware, Maryland, and North Carolina. Substantial water-level declines were also evident in the regional Lower Chesapeake aquifer in southeastern New Jersey; in the Castle Hayne-Piney Point aquifer in Delaware, Maryland, southern Virginia and east-central North Carolina; in the Peedee-Severn aquifer in east-central New Jersey and southeastern North Carolina; and in the Black Creek-Matawan aquifer in east-central New Jersey and east-central North Carolina. Conversely, declines were least severe in the regional Upper Chesapeake aquifer during this period. In the Southeastern Coastal Plain, declines of more than 100 ft in the Chattahoochee River aquifer occurred in eastern South Carolina and in southwestern Georgia, where water levels had declined approximately 140 and 200 ft from prepumping conditions, respectively. Within the Upper Floridan aquifer, decline was most pronounced in the coastal areas of Georgia and northern Florida where ground-water withdrawals were at their highest. These areas included Savannah, Jesup, and Brunswick, Ga., as well as the St. Marys, Ga. and Fernandina Beach, Fla., area. Regional water levels had declined by 80 ft near Brunswick and Fernandina Beach to as much as 160 ft near Savannah. Since 1980, water levels in many areas have continued to fall; however, in some places the rate at which levels declined has slowed. Conservation measures have served to limit withdrawals in affected areas, moderating or stabilizing water-level decline, and in some cases, resulting in substantial recovery. In other cases, increases in ground-water pumpage have resulted in continued rapid decline in water levels. From 1980 to 2000, water levels across the regional Upper, Middle, and Lower Potomac aquifers continued to decline across large parts of Delaware, Maryland, Virginia, and North Carolina, and water levels had stabilized or recovered throughout much of Long Island and New Jersey. Substantial water-level recovery had also occurred in east-central New Jersey in the Peedee-Severn and Black Creek-Matawan aquifers and in east-central North Carolina in the Castle Hayne-Piney Point aquifer. Substantial declines from about 1980 to about 2000 occurred in the Peedee-Severn aquifer in southern New Jersey, the Beaufort-Aquia aquifer in southern Maryland, and the Black Creek-Matawan and Upper Potomac aquifers in central and southern parts of the coastal plain in North Carolina. From 1980 to about 2000, water levels within the regional Upper Floridan aquifer had generally stabilized in response to shifting withdrawal patterns and reductions in pumpage at many places within the coastal region. Ground-water levels had stabilized and recovered at the ma

Reconstruction of paleoenvironmental changes based on the planktonic foraminiferal assemblages off Shimokita (Japan) in the northwestern North Pacific

NASA Astrophysics Data System (ADS)

Kuroyanagi, Azumi; Kawahata, Hodaka; Narita, Hisashi; Ohkushi, Ken'ichi; Aramaki, Takafumi

2006-08-01

Planktonic foraminifera live in the upper ocean, and their assemblages can record the surrounding environment. To reconstruct changes in water masses and the timing of flow of the Oyashio and Tsugaru currents through the Tsugaru Strait after the Last Glacial Maximum, when the Japan Sea had been almost isolated from the surrounding seas, we investigated at high resolution the planktonic foraminiferal fauna in seafloor sediments off the Shimokita (core MD01-2409: 41°33.9'N, 141°52.1'E), in the northwestern North Pacific, over the last 26,900 years. Factor analysis of the foraminiferal assemblage suggests that the water mass changed significantly as a result of the deglacial sea-level rise and opening of the straits into the Japan Sea. Mass accumulation rates of some selected foraminiferal species that inhabit characteristic environments (e.g., warm stratified water, Oyashio Current, Tsushima Current) corroborate these changes in water mass and water column structure. We also used the ratio of the dextral form to total Neogloboquadrina pachyderma as an indicator of subsurface (below the pycnocline) water temperature. We recognized five distinct periods of oceanographic change at the study site, which is just east of the Tsugaru Strait: (1) Oyashio Current affecting both surface and subsurface waters (26.9-15.7 thousand calendar years before present (cal. kyr BP)); (2) vertical mixing and subsurface warming as the Oyashio Current began to flow into the Japan Sea through the Tsugaru Strait (15.7-10.6 cal. kyr BP); (3) outflow of the Tsugaru Current from the Japan Sea into the Pacific, leading to baroclinic conditions, with the surface layer under the influence of the Tsugaru and the subsurface layers of the Oyashio Current (10.6-9.0 cal. kyr BP); (4) stratification of the water column developed as the flow of the Tsugaru Current increased (9.0-6.2 cal. kyr BP); and (5) warming of the subsurface layer, disruption of the stratification, and dominance of the Tsugaru Current in both surface and subsurface layers, similar to the present situation (6.2-1.5 cal. kyr BP). The timing of flow of the Oyashio and Tsugaru currents through the strait at the study site off Shimokita is generally compatible with the results of studies in the Japan Sea. The flow of the Tsugaru Current led to progressive warming of the waters, from the surface to the subsurface layers and from the Japan Sea side to the Pacific side of the Tsugaru Strait, beginning in 8.3-6.8 cal. kyr BP on the western side, and in 6.2 cal. kyr BP on the eastern side of the strait. By 4.8 cal. kyr BP on the western side, and by ˜ 3.4 cal. kyr BP on the eastern side of the strait, warm water prevailed in both surface and subsurface layers.

Major Texas floods of 1935

USGS Publications Warehouse

Dalrymple, Tate

1939-01-01

In localities where highly mineralized water is present in beds above and below the beds that yield the supplies of fresh water it is necessary to be able to locate leaks in wells in order to know whether the wells are being contaminated through holes in the casings or whether the fresh water supply is failing. Four general methods of detecting salt-water leaks have been used. In the pumping method, samples taken at measured time intervals while the well is being pumped show by their progressive change in salinity if salt water is being drawn in. In the velocity method, which is suitable for use only in artesian wells, a current meter lowered into the well indicates the location of possible salt water leaks by determining the levels at which there are changes in the rate of upward movement of the water. In the sampler method a container lowered into the well brings up a sample from any depth desired for analysis of its chloride content. The electric conductivity method, for which special apparatus was designed, has been used successfully in the Winter Garden area and Kleberg County, Tex., and in Sarasota County, Fla. The procedure in this method was to lower a pair of insulated electrodes into the well and measure the resistance of the water between them with the Wheatstone bridge or, in waters low in chloride, to apply a direct current of low voltage and measure the current flowing between .the electrodes by means of a milliammeter. The installments showed a marked increase in the conductivity of the water as the electrodes passed from fresh to salt water in the well, leaving no doubt as to the location of the leaks.

Recent distribution of lead in the Indian Ocean reflects the impact of regional emissions.

PubMed

Echegoyen, Yolanda; Boyle, Edward A; Lee, Jong-Mi; Gamo, Toshitaka; Obata, Hajime; Norisuye, Kazuhiro

2014-10-28

Humans have injected lead (Pb) massively into the earth surface environment in a temporally and spatially evolving pattern. A significant fraction is transported by the atmosphere into the surface ocean where we can observe its transport by ocean currents and sinking particles. This study of the Indian Ocean documents high Pb concentrations in the northern and tropical surface waters and extremely low Pb levels in the deep water. North of 20°S, dissolved Pb concentrations decrease from 42 to 82 pmol/kg in surface waters to 1.5-3.3 pmol/kg in deep waters. South of 20°S, surface water Pb concentrations decrease from 21 pmol/kg at 31°S to 7 pmol/kg at 62°S. This surface Pb concentration gradient reflects a southward decrease in anthropogenic Pb emissions. The upper waters of the north and central Indian Ocean have high Pb concentrations resulting from recent regional rapid industrialization and a late phase-out of leaded gasoline, and these concentrations are now higher than currently seen in the central North Pacific and North Atlantic oceans. The Antarctic sector of the Indian Ocean shows very low concentrations due to limited regional anthropogenic Pb emissions, high scavenging rates, and rapid vertical mixing, but Pb still occurs at higher levels than would have existed centuries ago. Penetration of Pb into the northern and central Indian Ocean thermocline waters is minimized by limited ventilation. Pb concentrations in the deep Indian Ocean are comparable to the other oceans at the same latitude, and deep waters of the central Indian Ocean match the lowest observed oceanic Pb concentrations.

A Survey of N'-Nitrosonornicotine (NNN) and Total Water Content in Select Smokeless Tobacco Products Purchased in the United States in 2015.

PubMed

Ammann, Jeffrey R; Lovejoy, Katherine S; Walters, Matthew J; Holman, Matthew R

2016-06-01

This investigation provides an updated survey measuring the levels of N'-nitrosonornicotine (NNN) and water content of a select number of smokeless tobacco products sold in the United States in 2015. A total of 34 smokeless tobacco products were collected and analyzed for NNN and water content using LC-MS/MS and GC-TCD, respectively. Smokeless tobacco products were chosen to obtain a representative sample of the different types of products on the U.S. market. These smokeless products represent 12 of the 25 top-selling smokeless tobacco products according to 2013 Nielsen net sales data while five of the smokeless tobacco products are of lower selling smokeless tobacco products. The NNN levels and the water content of the smokeless tobacco products were determined and compared to previous studies. Although the range of NNN levels found was broad for the examined smokeless tobacco products (0.64-12.0 μg/g dry weight), dry snuff had the highest levels of NNN observed (>5 μg/g dry weight). We observed a general decrease in NNN levels for the same six moist snuff products that were analyzed in 2004 compared to our current 2015 study. The water content of the smokeless tobacco products surveyed ranged from 3.92 to 54.8%.

A Survey of N′-Nitrosonornicotine (NNN) and Total Water Content in Select Smokeless Tobacco Products Purchased in the United States in 2015

PubMed Central

Ammann, Jeffrey R.; Lovejoy, Katherine S.; Walters, Matthew J.; Holman, Matthew R.

2016-01-01

This investigation provides an updated survey measuring the levels of N′-nitrosonornicotine (NNN) and water content of a select number of smokeless tobacco products sold in the United States in 2015. A total of 34 smokeless tobacco products were collected and analyzed for NNN and water content using LC-MS/MS and GC-TCD, respectively. Smokeless tobacco products were chosen to obtain a representative sample of the different types of products on the U.S. market. These smokeless products represent 12 of the 25 top-selling smokeless tobacco products according to 2013 Nielsen net sales data while five of the smokeless tobacco products are of lower selling smokeless tobacco products. The NNN levels and the water content of the smokeless tobacco products were determined and compared to previous studies. Although the range of NNN levels found was broad for the examined smokeless tobacco products (0.64–12.0 µg/g dry weight), dry snuff had the highest levels of NNN observed (>5 µg/g dry weight). We observed a general decrease in NNN levels for the same six moist snuff products that were analyzed in 2004 compared to our current 2015 study. The water content of the smokeless tobacco products surveyed ranged from 3.92 to 54.8%. PMID:27192054

Simulated effects of projected withdrawals from the Wenonah-Mount Laurel Aquifer on ground-water levels in the Camden, New Jersey, area and vicinity

USGS Publications Warehouse

Navoy, A.S.

1994-01-01

The Wenonah-Mount Laurel aquifer is being considered as a potential source of future water supply for the Camden, New Jersey, area. The deeper Potomac- Raritan-Magothy aquifer system is currently the major major source of water supply for the area, but its use may be curtailed or reduced by 35 percent of 1983 withdrawals through its designation by the New Jersey Department of Environmental Protection and Energy as "Water Supply Critical Area#2." Withdrawals from the Wenonah-Mount Laurel aquifer currently (1989) total about 7 million gallons per day. The anticipated use of this aquifer by communities with access to it, as an alternative supply, could increase to more than 14 million gallons per day by 2020. If the communities of Clayton and Glassboro decrease their withdrawals from the Potomac-Raritan-Magothy aquifer system by 50 percent or cease them entirely because of their proximity to saline water, the use of Wenonah-Mount Laurel aquifer could increase to greater than 15 million gallons per day by 2020. Simulation of the ground-water system indicates that the projected increase in withdrawals will cause cones of depression in the potentiometric surface of the Wenonah-Mount Laurel aquifer in the Camden metro- politan area by 2020 that extend to depths ranging from 10 feet above sea level to 60 feet below sea level. This represents a secline of about 40 to 100 feet thr 1990 conditions. Withdrawals in northeastern Burlington County will cause a large cone of depression that, by 2020, will extend to depths of about 220 feet below sea level, represent- ing a decline of about 140 feet from 1990 conditions. Simulation results indicate that water levels in the Wenonah-Mount Laurel aquifer near the Salem Nuclear Power Plant are somewhat insensitive to withdrawals elsewhere in the aquifer. In some areas, especially in Burlington County, the cones of depression have developed in proximity to the aquifer-outcrop area and could induce infiltration from streams crossing the outcrop. Because of the hydraulic connection to adjacent aquifers, future management plans need to be developed in a compre- hensive manner with regard to all aquifers. Further study of the aquifer in Salem County could provide additional information on the hydraulic connection to Delaware Bay and the potential for saltwater intrusion.

Low-level arsenic exposure from drinking water is associated with prostate cancer in Iowa.

PubMed

Roh, Taehyun; Lynch, Charles F; Weyer, Peter; Wang, Kai; Kelly, Kevin M; Ludewig, Gabriele

2017-11-01

Inorganic arsenic is a toxic naturally occurring element in soil and water in many regions of the US including the Midwest. Prostate cancer is the second most common type of cancer in men in Iowa, surpassed only by non-melanotic skin cancer. Epidemiology studies have evaluated arsenic exposure from drinking water and prostate cancer, but most have focused on high-level exposures outside the US. As drinking water from groundwater sources is a major source of arsenic exposure, we conducted an ecologic study to evaluate prostate cancer and arsenic in drinking water from public water sources and private wells in Iowa, where exposure levels are low, but duration of exposure can be long. Arsenic data from public water systems were obtained from the Iowa Safe Drinking Water Information System for the years 1994-2003 and for private wells from two Iowa Well Water Studies, the Iowa Community Private Well Study (ICPWS, 2002-2003) and Iowa Statewide Rural Well Water Survey Phase 2 (SWIRL2, 2006-2008) that provided data for 87 Iowa counties. Prostate cancer incidence data from 2009 to 2013 for Iowa were obtained from Surveillance, Epidemiology and End Results' SEER*Stat software. County averages of water arsenic levels varied from 1.08 to 18.6 ppb, with three counties above the current 10 ppb limit. Based on the tertiles of arsenic levels, counties were divided into three groups: low (1.08-2.06 ppb), medium (2.07-2.98 ppb), and high (2.99-18.6 ppb). Spatial Poisson regression modeling was conducted to estimate the risk ratios (RR) of prostate cancer by tertiles of arsenic level at a county level, adjusted for demographic and risk factors. The RR of prostate cancer were 1.23 (95% CI, 1.16-1.30) and 1.28 (95% CI, 1.21-1.35) in the medium and high groups, respectively, compared to the low group after adjusting for risk factors. The RR increased to 1.36 (95% CI, 1.28-1.45) in the high group when analyses were restricted to aggressive prostate cancers (Gleason score ≥ 7). This study shows a significant dose-dependent association between low-level arsenic exposure and prostate cancer, and if this result is replicated in future individual-level studies, may suggest that 10 ppb is not protective for human health. Copyright © 2017 Elsevier Inc. All rights reserved.

Water footprint assessment along the wheat-bread value chain towards the sustainable use of freshwater in South Africa

NASA Astrophysics Data System (ADS)

Mohlotsane, Pascalina; Owusu-Sekyere, Enoch; Jordaan, Henry

2017-04-01

A significant amount of water is used in food production. The current increase in demand for food and impact of climate change place much pressure on the available water resources. South Africa is soon approaching complete utilisation of its available surface water, with irrigated agriculture accountable for about 63% of the country's available water use. This poses a threat to food security. Wheat is the largest winter cereal crop produced in South Africa, approximately 80% of this wheat is used to produce Bread. Bread consumption in South Africa is estimated at 2.8 billion loaves per annum. About 62 loaves of bread are consumed per person per annum with noticeable differences in preferences. Therefore, it is important to account for the amount of water used along the wheat-bread production chain. In this paper, we examined water footprint along the wheat-bread value chain. The water footprint concept provides an appropriate framework for analysis to find the link between the consumption of agricultural goods and the use of water resources. The paper employed the Global Water Footprint Standard approach to calculating the volumetric green, blue and grey water footprint along the wheat-bread value chain. Our findings reveal that wheat production at the farm level accounts for 99.95 percent of the total water footprint of the bread, while processing and wholesale levels only account for 0.56 per cent. Our findings highlight the importance of effective and efficient water use at the farm level for wheat production. Specifically, the total water footprint of wheat bread is 937.42m3.ton-1. The green water component was found to be 190.59m3.ton-1 and that of blue water was 745.28 m3.ton-1. Grey water footprint accounted for only 1.55 m3.ton-1. The results indicate that the amount of water used at farm level is the largest contributor to the total water footprint of bread. Given the blue water scarcity situation in South Africa, it is very critical for wheat producers to pay particular attention to the large blue water usage in order to be sustainable in their production. Economically, we found that value added to water as it moves along the wheat-bread value chain varies from one stage to another. More value is added to water at the farm level, relative to the milling and bakery levels. Hence, we recommend that the economic dimension of water utilisation should be considered in the production decision of food producers.

Humanity's unsustainable environmental footprint.

PubMed

Hoekstra, Arjen Y; Wiedmann, Thomas O

2014-06-06

Within the context of Earth's limited natural resources and assimilation capacity, the current environmental footprint of humankind is not sustainable. Assessing land, water, energy, material, and other footprints along supply chains is paramount in understanding the sustainability, efficiency, and equity of resource use from the perspective of producers, consumers, and government. We review current footprints and relate those to maximum sustainable levels, highlighting the need for future work on combining footprints, assessing trade-offs between them, improving computational techniques, estimating maximum sustainable footprint levels, and benchmarking efficiency of resource use. Ultimately, major transformative changes in the global economy are necessary to reduce humanity's environmental footprint to sustainable levels. Copyright © 2014, American Association for the Advancement of Science.

Integrated Monitoring of the Soya Warm Current Using HF Ocean Radars, Satellite Altimeters, Coastal Tide Gauges, and a Bottom-Mounted ADCP

NASA Astrophysics Data System (ADS)

Ebuchi, N.; Fukamachi, Y.; Ohshima, K. I.; Wakatsuchi, M.

2007-12-01

The Soya Warm Current (SWC) is a coastal boundary current, which flows along the coast of Hokkaido in the Sea of Okhotsk. The SWC flows into the Sea of Okhotsk from the Sea of Japan through the Soya/La Perouse Strait, which is located between Hokkaido, Japan, and Sakhalin, Russia. It supplies warm, saline water in the Sea of Japan to the Sea of Okhotsk and largely affects the ocean circulation and water mass formation in the Sea of Okhotsk, and local climate, environment and fishery in the region. However, the SWC has never been continuously monitored due to the difficulties involved in field observations related to, for example, severe weather conditions in the winter, political issues at the border strait, and conflicts with fishing activities in the strait. Detailed features of the SWC and its variations have not yet been clarified. In order to monitor variations in the SWC, three HF ocean radar stations were installed around the strait. The radar covers a range of approximately 70 km from the coast. It is shown that the HF radars clearly capture seasonal and subinertial variations of the SWC. The velocity of the SWC reaches its maximum, approximately 1 m/s, in summer, and weakens in winter. The velocity core is located 20 to 30 km from the coast, and its width is approximately 50 km. The surface transport by the Soya Warm Current shows a significant correlation with the sea level difference along the strait, as derived from coastal tide gauge records. The cross-current sea level difference, which is estimated from the sea level anomalies observed by the Jason-1 altimeter and a coastal tide gauge, also exhibits variation in concert with the surface transport and along-current sea level difference.

Effects of moisture and nitrogen stress on gas exchange and nutrient resorption in Quercus rubra seedlings

Treesearch

K. Francis Salifu; Douglass F. Jacobs

2008-01-01

The effects of simulated soil fertility at three levels (poor, medium, and rich soils) and moisture stress at two levels (well watered versus moisture stressed) on gas exchange and foliar nutrient resorption in 1+0 bareroot northern red oak (Quercus rubra) seedlings were evaluated. Current nitrogen (N) uptake was labeled with the stable isotope

Impact of climate change on Gironde Estuary

NASA Astrophysics Data System (ADS)

Laborie, Vanessya; Hissel, François; Sergent, Philippe

2014-05-01

Within the THESEUS European project, a simplified mathematical model for storm surge levels in the Bay of Biscay was adjusted on 10 events at Le Verdon using wind and pressure fields from CLM/SGA, so that the water levels at Le Verdon have the same statistic quantiles as observed tide records for the period [1960-2000]. The analysis of future storm surge levels shows a decrease in their quantiles at Le Verdon, whereas there is an increase of the quantiles of total water levels. This increase is smaller than the sea level rise and gets even smaller as one enters farther upstream in the estuary. A numerical model of the Gironde Estuary was then used to evaluate future water levels at 6 locations of the estuary from Le Verdon to Bordeaux and to assess the changes in the quantiles of water levels during the XXIst century using ONERC's pessimistic scenario for sea level rise (60 cm). The model was fed by several data sources : wind fields at Royan and Mérignac interpolated from the grid of the European Climatolologic Model CLM/SGA, a tide signal at Le Verdon, the discharges of Garonne (at La Réole), the Dordogne (at Pessac) and Isle (at Libourne). A series of flood maps for different return periods between 2 and 100 years and for four time periods ([1960-1999], [2010-2039], [2040-2069] and [2070-2099]) have been built for the region of Bordeaux. Quantiles of water levels in the floodplain have also been calculated. The impact of climate change on the evolution of flooded areas in the Gironde Estuary and on quantiles of water levels in the floodplain mainly depends on the sea level rise. Areas which are not currently flooded for low return periods will be inundated in 2100. The influence of river discharges and dike breaching should also be taken into account for more accurate results.

Analysis of changes in water-level dynamics at selected sites in the Florida Everglades

USGS Publications Warehouse

Conrads, Paul; Benedict, Stephen T.

2013-01-01

The historical modification and regulation of the hydrologic patterns in the Florida Everglades have resulted in changes in the ecosystem of South Florida and the Florida Everglades. Since the 1970s, substantial focus has been given to the restoration of the Everglades ecosystem. The U.S. Geological Survey through its Greater Everglades Priority Ecosystem Science and National Water-Quality Assessment Programs has been providing scientific information to resource managers to assist in the Everglades restoration efforts. The current investigation included development of a simple method to identify and quantify changes in historical hydrologic behavior within the Everglades that could be used by researchers to identify responses of ecological communities to those changes. Such information then could be used by resource managers to develop appropriate water-management practices within the Everglades to promote restoration. The identification of changes in historical hydrologic behavior within the Everglades was accomplished by analyzing historical time-series water-level data from selected gages in the Everglades using (1) break-point analysis of cumulative Z-scores to identify hydrologic changes and (2) cumulative water-level frequency distribution curves to evaluate the magnitude of those changes. This analytical technique was applied to six long-term water-level gages in the Florida Everglades. The break-point analysis for the concurrent period of record (1978–2011) identified 10 common periods of changes in hydrologic behavior at the selected gages. The water-level responses at each gage for the 10 periods displayed similarity in fluctuation patterns, highlighting the interconnectedness of the Florida Everglades hydrologic system. While the patterns were similar, the analysis also showed that larger fluctuations in water levels between periods occurred in Water Conservation Areas 2 and 3 in contrast to those in Water Conservation Area 1 and the Everglades National Park. Results from the analysis indicate that the cumulative Z-score curve, in conjunction with cumulative water-level frequency distribution curves, can be a useful tool in identifying and quantifying changes in historical hydrologic behavior within the Everglades. In addition to the analysis, a spreadsheet application was developed to assist in applying these techniques to time-series water-level data at gages within the Everglades and is included with this report.

Analysis of projected water availability with current basin management plan, Pajaro Valley, California

NASA Astrophysics Data System (ADS)

Hanson, R. T.; Lockwood, B.; Schmid, Wolfgang

2014-11-01

The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within ;water-balance subregions; (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori. The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations and assumptions of 2009 urban water demand and land use. Water supplied directly from precipitation, and indirectly from reuse, captured local runoff, and groundwater is necessary but inadequate to satisfy agricultural demand without coastal and regional storage depletion that facilitates seawater intrusion. These facilities reduce potential seawater intrusion by about 45% with groundwater levels in the four regions served by the CDS projected to recover to levels a few feet above sea level. The projected recoveries are not high enough to prevent additional seawater intrusion during dry-year periods or in the deeper aquifers where pumpage is greater. While these facilities could reduce coastal pumpage by about 55% of the historical 2000-2009 pumpage for these regions, and some of the water is delivered in excess of demand, other coastal regions continue to create demands on coastal pumpage that will need to be replaced to reduce seawater intrusion. In addition, inland urban and agricultural demands continue to sustain water levels below sea level causing regional landward gradients that also drive seawater intrusion. Seawater intrusion is reduced by about 45% but it supplies about 55% of the recovery of groundwater levels in the coastal regions served by the CDS. If economically feasible, water from summer agricultural runoff and tile-drain returnflows could be another potential local source of water that, if captured and reused, could offset the imbalance between supply and demand as well as reducing discharge of agricultural runoff into the National Marine Sanctuary of Monterey Bay. A BMP update (2012) identifies projects and programs that will fund a conservation program and will provide additional, alternative water sources to reduce or replace coastal and inland pumpage, and to replenish the aquifers with managed aquifer recharge in an inland portion of the Pajaro Valley.

Nutrient Pumping/Advection by Propagating Rossby Waves in the Kuroshio Extension

DTIC Science & Technology

2010-01-01

sea-elevation changes or SLA variance levels are a maximum as eddies and meanders cross a mean route. This boundary in terms of Chl- a levels (lower...and elevated Chl- a levels ) is south of the KE jet. Kuroshio Extension meanders and rings carry different water types across a mean Kuroshio Extension...Fig. 5A). The ring or eddy currents may also redistribute the surface Chl- a levels , drawing out plumes of locally increased Chl-a from regions of

Development of an integrated hydrological modeling system for near-real-time multi-objective reservoir operation in large river basins

NASA Astrophysics Data System (ADS)

Wang, L.; Koike, T.

2010-12-01

The climate change-induced variability in hydrological cycles directly affects regional water resources management. For improved multiple multi-objective reservoir operation, an integrated modeling system has been developed by incorporating a global optimization system (SCE-UA) into a distributed biosphere hydrological model (WEB-DHM) coupled with the reservoir routing module. The reservoir storage change is estimated from the difference between the simulated inflows and outflows; while the reservoir water level can be defined from the updated reservoir storage by using the H-V curve. According to the reservoir water level, the new operation rule can be decided. For optimization: (1) WEB-DHM is calibrated for each dam’s inflows separately; (2) then the calibrated WEB-DHM is used to simulate inflows and outflows by assuming outflow proportional to inflow; and (3) the proportion coefficients are optimized with Shuffle Complex Evolution method (SCE-UA), to fulfill an objective function towards minimum flood risk at downstream and maximum reservoir water storage for future use. The GSMaP product offers hourly global precipitation maps in near real-time (about four hours after observation). Aiming at near real-time reservoir operation in large river basins, the integrated modeling system takes the inputs from both an operational global quantitative precipitation forecast (JMA-GPV; to achieve an optimal operation rule in the assumed lead time period) and the GSMaP product (to perform current operation with the obtained optimal rule, after correction by gauge rainfall). The newly-developed system was then applied to the Red River Basin, with an area of 160,000 km2, to test its performance for near real-time dam operation. In Vietnam, three reservoirs are located in the upstream of Hanoi city, with Hoa Binh the largest (69% of total volume). After calibration with the gauge rainfall, the inflows to three reservoirs are well simulated; the discharge and water level at Hanoi city are also well reproduced with the actual dam releases. With the corrected GSMaP rainfall (by using gauge rainfall), the inflows to reservoirs and the water level at Hanoi city can be also reasonably reproduced. The study aims at achieving an optimal operation rule in the lead time period (with the quantitative precipitation forecast) and then using it to perform current operation (with the corrected GSMaP rainfall). At Hanoi, there are relatively low flows in July, but high floods in August 2005. Results show that with the actual operation, dangerous water level in Hanoi was observed; while with the lead-time operation, the water level in Hanoi can be obviously cut down, and maximum water storage is also achieved for Hoa Binh reservoir at the end of flood season.

Effect of water table management and elevated CO2 on radish productivity and on CH4 and CO2 fluxes from peatlands converted to agriculture.

PubMed

Musarika, S; Atherton, C E; Gomersall, T; Wells, M J; Kaduk, J; Cumming, A M J; Page, S E; Oechel, W C; Zona, D

2017-04-15

Anthropogenic activity is affecting the global climate through the release of greenhouse gases (GHGs) e.g. CO 2 and CH 4 . About a third of anthropogenic GHGs are produced from agriculture, including livestock farming and horticulture. A large proportion of the UK's horticultural farming takes place on drained lowland peatlands, which are a source of significant amounts of CO 2 into the atmosphere. This study set out to establish whether raising the water table from the currently used -50cm to -30cm could reduce GHGs emissions from agricultural peatlands, while simultaneously maintaining the current levels of horticultural productivity. A factorial design experiment used agricultural peat soil collected from the Norfolk Fens (among the largest of the UK's lowland peatlands under intensive cultivation) to assess the effects of water table levels, elevated CO 2 , and agricultural production on GHG fluxes and crop productivity of radish, one of the most economically important fenland crops. The results of this study show that a water table of -30cm can increase the productivity of the radish crop while also reducing soil CO 2 emissions but without a resultant loss of CH 4 to the atmosphere, under both ambient and elevated CO 2 concentrations. Elevated CO 2 increased dry shoot biomass, but not bulb biomass nor root biomass, suggesting no immediate advantage of future CO 2 levels to horticultural farming on peat soils. Overall, increasing the water table could make an important contribution to global warming mitigation while not having a detrimental impact on crop yield. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Exceptionally fast growth rate of <100-yr-old tufa, Big Soda Lake, Nevada: Implications for using tufa as a peleoclimate proxy

USGS Publications Warehouse

Rosen, Michael R.; Arehart, G.B.; Lico, M.S.

2004-01-01

Large tufa mounds (>3 m tall, with a basal circumference of 5 m) have been discovered on the margin of Big Soda Lake, Nevada, USA. These tufa mounds are rooted at a maximum of 4 m below the current lake surface and are actively forming from groundwater seepage, which can be seen emanating from the top of the tufa mounds. Big Soda Lake is a volcanic crater lake whose water level is maintained exclusively by groundwater. The age of the tufa mounds is well constrained because prior to the development of the Newlands Irrigation Project in 1907, the water level was ???18 m lower than the current lake level. The vertical columnar nature of the tufa mounds indicates that they formed under the lake and not subaerially. Thus, the tufa mounds are <100 yr old and have grown at a rate ???30 mm/yr. Stable oxygen and carbon isotope analyses of tufa carbonate compared to isotopic analyses of groundwater and lake water and hydrochemical data indicate that the fluids responsible for their precipitation are a simple mixture of modern groundwater and lake water and do not reflect a recent climate signature. The exceptionally fast growth of the tufa mounds indicates that large tufa deposits may form almost instantaneously in geologic time. Given this potential for rapid growth and the fact that variations in isotopic compositions of tufa deposits have been interpreted in terms of changes in paleoclimate and changes in the composition of recharge water over thousands of years, care should be taken when trying to determine the significance of variations in isotopic or chemical compositions of tufas that may have been caused by mixing with groundwater. ?? 2004 Geological Society of America.

Field Assessment of a Novel Household-Based Water Filtration Device: A Randomised, Placebo-Controlled Trial in the Democratic Republic of Congo

PubMed Central

Boisson, Sophie; Kiyombo, Mbela; Sthreshley, Larry; Tumba, Saturnin; Makambo, Jacques; Clasen, Thomas

2010-01-01

Background Household water treatment can improve the microbiological quality of drinking water and may prevent diarrheal diseases. However, current methods of treating water at home have certain shortcomings, and there is evidence of bias in the reported health impact of the intervention in open trial designs. Methods and Findings We undertook a randomised, double-blinded, placebo-controlled trial among 240 households (1,144 persons) in rural Democratic Republic of Congo to assess the field performance, use and effectiveness of a novel filtration device in preventing diarrhea. Households were followed up monthly for 12 months. Filters and placebos were monitored for longevity and for microbiological performance by comparing thermotolerant coliform (TTC) levels in influent and effluent water samples. Mean longitudinal prevalence of diarrhea was estimated among participants of all ages. Compliance was assessed through self-reported use and presence of water in the top vessel of the device at the time of visit. Over the 12-month follow-up period, data were collected for 11,236 person-weeks of observation (81.8% total possible). After adjusting for clustering within the household, the longitudinal prevalence ratio of diarrhoea was 0.85 (95% confidence interval: 0.61–1.20). The filters achieved a 2.98 log reduction in TTC levels while, for reasons that are unclear, the placebos achieved a 1.05 log reduction (p<0.0001). After 8 months, 68% of intervention households met the study's definition of current users, though most (73% of adults and 95% of children) also reported drinking untreated water the previous day. The filter maintained a constant flow rate over time, though 12.4% of filters were damaged during the course of the study. Conclusions While the filter was effective in improving water quality, our results provide little evidence that it was protective against diarrhea. The moderate reduction observed nevertheless supports the need for larger studies that measure impact against a neutral placebo. Trial Registration Current Controlled Trials ISRCTN03844341 PMID:20856584

Backwater development by woody debris

NASA Astrophysics Data System (ADS)

Geertsema, Tjitske; Torfs, Paul; Teuling, Ryan; Hoitink, Ton

2017-04-01

Placement of woody debris is a common method for increasing ecological values in river and stream restoration, and is thus widely used in natural environments. Water managers, however, are afraid to introduce wood in channels draining agricultural and urban areas. Upstream, it may create backwater, depending on hydrodynamic characteristics including the obstruction ratio, the Froude number and the surface level gradient. Patches of wood may trigger or counter morphological activity, both laterally, through bank erosion and protection, and vertically, with pool and riffle formation. Also, a permeable construction composed of wood will weather over time. Both morphodynamic activity and weathering cause backwater effects to change in time. The purpose of this study is to quantify the time development of backwater effects caused by woody debris. Hourly water levels gauged upstream and downstream of patches and discharge are collected for five streams in the Netherlands. The water level drop over the woody debris patch relates to discharge in the streams. This relation is characterized by an increasing water level difference for an increasing discharge, up to a maximum. If the discharge increases beyond this level, the water level difference reduces to the value that may represent the situation without woody debris. This reduction depends primarily on the obstruction ratio of the woody debris in the channel cross-section. Morphologic adjustments in the stream and reorientation of the woody material reduce the water level drop over the patches in time. Our results demonstrate that backwater effects can be reduced by optimizing the location where woody debris is placed and manipulating the obstruction ratio. Current efforts are focussed on representing woody debris in a one-dimensional numerical model, aiming to obtain a generic tool to achieve a stream design with woody debris that minimizes backwater.

Advanced Life Support Technologies and Scenarios

NASA Technical Reports Server (NTRS)

Barta, Daniel J.

2011-01-01

As NASA looks beyond the International Space Station toward long-duration, deep space missions away from Earth, the current practice of supplying consumables and spares will not be practical nor affordable. New approaches are sought for life support and habitation systems that will reduce dependency on Earth and increase mission sustainability. To reduce launch mass, further closure of Environmental Control and Life Support Systems (ECLSS) beyond the current capability of the ISS will be required. Areas of particular interest include achieving higher degrees of recycling within Atmosphere Revitalization, Water Recovery and Waste Management Systems. NASA is currently investigating advanced carbon dioxide reduction processes that surpass the level of oxygen recovery available from the Sabatier Carbon Dioxide Reduction Assembly (CRA) on the ISS. Improving the efficiency of the recovery of water from spacecraft solid and liquid wastes is possible through use of emerging technologies such as the heat melt compactor and brine dewatering systems. Another significant consumable is that of food. Food production systems based on higher plants may not only contribute significantly to the diet, but also contribute to atmosphere revitalization, water purification and waste utilization. Bioreactors may be potentially utilized for wastewater and solid waste management. The level at which bioregenerative technologies are utilized will depend on their comparative requirements for spacecraft resources including mass, power, volume, heat rejection, crew time and reliability. Planetary protection requirements will need to be considered for missions to other solar system bodies.

Modeling waves and circulation in Lake Pontchartrain, Louisiana

USGS Publications Warehouse

Signell, Richard P.; List, Jeffrey H.

1997-01-01

The U.S. Geological Survey is conducting a study of storm-driven sediment resuspension and transport in Lake Pontchartrain, Louisiana. Two critical processes related to sediment transport in the lake are (1) the resuspension of sediments due to wind-generated storm waves and (2) the movement of resuspended material by lake currents during storm wind events. The potential for sediment resuspension is being studied with the wave prediction model which simulates local generation of waves by wind and shallow-water effects on waves (refraction, shoaling, bottom friction, and breaking). Long-term wind measurements are then used to determine the regional "climate" of bottom orbital velocity (showing the spatial and temporal variability of wave-induced currents at the bottom). The circulation of the lake is being studied with a three-dimensional hydrodynamic model. Results of the modeling effort indicate that remote forcing due to water levels in Mississippi Sound dominate the circulation near the passes in the eastern end of the lake, while local wind forcing dominates water movement in the western end. During typical storms with winds from the north-northeast or the south-southeast, currents along the south coast near New Orleans generally transport material westward, while material in the central region moves against the wind. When periods of sustained winds are followed by a drop in coastal sea level, a large amount of suspended sediment can be flushed from the lake.

The 'selfish brain' is regulated by aquaporins and autophagy under nutrient deprivation.

PubMed

Ye, Qiao; Wu, Yonghong; Gao, Yan; Li, Zhihui; Li, Weiguang; Zhang, Chenggang

2016-05-01

The brain maintains its mass and physiological functional capacity compared with other organs under harsh conditions such as starvation, a mechanism termed the 'selfish brain' theory. To further investigate this phenomenon, mice were examined following water and/or food deprivation. Although the body weights of the mice, the weight of the organs except the brain and blood glucose levels were significantly reduced in the absence of water and/or food, the brain weight maintained its original state. Furthermore, no significant differences in the water content of the brain or its energy balance were observed when the mice were subjected to water and/or food deprivation. To further investigate the mechanism underlying the brain maintenance of water and substance homeostasis, the expression levels of aquaporins (AQPs) and autophagy‑specific protein long‑chain protein 3 (LC3) were examined. During the process of water and food deprivation, no significant differences in the transcriptional levels of AQPs were observed. However, autophagy activity levels were initially stimulated, then suppressed in a time‑dependent manner. LC3 and AQPs have important roles for the survival of the brain under conditions of food and water deprivation, which provided further understanding of the mechanism underlying the 'selfish brain' phenomenon. Although not involved in the energy regulation of the 'selfish brain', AQPs were observed to have important roles in water and food deprivation, specifically with regards to the control of water content. Additionally, the brain exhibits an 'unselfish strategy' using autophagy during water and/or food deprivation. The present study furthered current understanding of the 'selfish brain' theory, and identified additional regulating target genes of AQPs and autophagy, with the aim of providing a basis for the prevention of nutrient shortage in humans and animals.

The 'selfish brain' is regulated by aquaporins and autophagy under nutrient deprivation

PubMed Central

YE, QIAO; WU, YONGHONG; GAO, YAN; LI, ZHIHUI; LI, WEIGUANG; ZHANG, CHENGGANG

2016-01-01

The brain maintains its mass and physiological functional capacity compared with other organs under harsh conditions such as starvation, a mechanism termed the 'selfish brain' theory. To further investigate this phenomenon, mice were examined following water and/or food deprivation. Although the body weights of the mice, the weight of the organs except the brain and blood glucose levels were significantly reduced in the absence of water and/or food, the brain weight maintained its original state. Furthermore, no significant differences in the water content of the brain or its energy balance were observed when the mice were subjected to water and/or food deprivation. To further investigate the mechanism underlying the brain maintenance of water and substance homeostasis, the expression levels of aquaporins (AQPs) and autophagy-specific protein long-chain protein 3 (LC3) were examined. During the process of water and food deprivation, no significant differences in the transcriptional levels of AQPs were observed. However, autophagy activity levels were initially stimulated, then suppressed in a time-dependent manner. LC3 and AQPs have important roles for the survival of the brain under conditions of food and water deprivation, which provided further understanding of the mechanism underlying the 'selfish brain' phenomenon. Although not involved in the energy regulation of the 'selfish brain', AQPs were observed to have important roles in water and food deprivation, specifically with regards to the control of water content. Additionally, the brain exhibits an 'unselfish strategy' using autophagy during water and/or food deprivation. The present study furthered current understanding of the 'selfish brain' theory, and identified additional regulating target genes of AQPs and autophagy, with the aim of providing a basis for the prevention of nutrient shortage in humans and animals. PMID:26986971

Summary of hydrologic conditions in Kansas, water year 2014

USGS Publications Warehouse

Robison, Andrew L.

2015-01-01

The U.S. Geological Survey Kansas Water Science Center, in cooperation with Federal, State, and local agencies, maintains a long-term network of hydrologic monitoring gages in the State of Kansas. These include 206 real-time streamgages, 12 real-time reservoir-level monitoring stations, and 32 groundwater monitoring wells. These data and associated analyses, accumulated over time, provide a unique overview of hydrologic conditions and help improve our understanding of Kansas’s water resources. Yearly hydrologic conditions are determined by comparing statistical analyses of current and historical water year data for the period of record. These data are used in protecting life and property, and managing water resources for agricultural, industrial, public supply, ecological, and recreational purposes.

Ganga water pollution: A potential health threat to inhabitants of Ganga basin.

PubMed

Dwivedi, Sanjay; Mishra, Seema; Tripathi, Rudra Deo

2018-05-18

The water quality of Ganga, the largest river in Indian sub-continent and life line to hundreds of million people, has severely deteriorated. Studies have indicated the presence of high level of carcinogenic elements in Ganga water. We performed extensive review of sources and level of organic, inorganic pollution and microbial contamination in Ganga water to evaluate changes in the level of various pollutants in the recent decade in comparison to the past and potential health risk for the population through consumption of toxicant tainted fishes in Ganga basin. A systematic search through databases, specific websites and reports of pollution regulatory agencies was conducted. The state wise level of contamination was tabulated along the Ganga river. We have discussed the major sources of various pollutants with particular focus on metal/metalloid and pesticide residues. Bioaccumulation of toxicants in fishes of Ganga water and potential health hazards to humans through consumption of tainted fishes was evaluated. The level of pesticides in Ganga water registered a drastic reduction in the last decade (i.e. after the establishment of National Ganga River Basin Authority (NGRBA) in 2009), still the levels of some organochlorines are beyond the permissible limits for drinking water. Conversely the inorganic pollutants, particularly carcinogenic elements have increased several folds. Microbial contamination has also significantly increased. Hazard quotient and hazard index indicated significant health risk due to metal/metalloid exposure through consumption of tainted fishes from Ganga. Target cancer risk assessment showed high carcinogenic risk from As, Cr, Ni and Pb as well as residues of DDT and HCHs. Current data analysis showed that Ganga water quality is deteriorating day by day and at several places even in upper stretch of Ganga the water is not suitable for domestic uses. Although there is positive impact of ban on persistent pesticides with decreasing trend of pesticide residues in Ganga water, the increasing trend of trace and toxic elements is alarming and the prolong exposure to polluted Ganga water and/or consumption of Ganga water fishes may cause serious illness including cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

Flood-inundation maps for the White River at Spencer, Indiana

USGS Publications Warehouse

Nystrom, Elizabeth A.

2013-01-01

Digital flood-inundation maps for a 5.3-mile reach of the White River at Spencer, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage White River at Spencer, Indiana (sta. no. 03357000). Current conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/. National Weather Service (NWS)-forecasted peak-stage inforamation may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relation at the White River at Spencer, Indiana, streamgage and documented high-water marks from the flood of June 8, 2008. The hydraulic model was then used to compute 20 water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from the NWS action stage (9 feet) to the highest rated stage (28 feet) at the streamgage. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from Light Detection and Ranging (LiDAR) data) in order to delineate the area flooded at each water level. The availability of these maps along with Internet information regarding the current stage from the Spencer USGS streamgage and forecasted stream stages from the NWS will provide emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures, as well as for post-flood recovery efforts.

Texas Water Observatory: A platform for landscape-level assessment of human and natural water uses, productivity, carbon sequestration, and other ecosystem services

NASA Astrophysics Data System (ADS)

Jaimes, A.; Gaur, N.; Moore, G. W.; Miller, G. R.; Morgan, C.; Everett, M. E.; Noormets, A.; Mohanty, B.

2017-12-01

The increasing temperature, and growing variability and intensity of precipitation events have strained the water supplies of several metropolitan areas in the Southern USA. The need for better system-level understanding and data-based planning tools to support the needs of 50 million habitants of Texas and the Gulf States led the establishment of Texas Water Observatory (TWO; http://two.tamu.edu/sites.aspx) in 2015. Using the Brazos River watershed as a model system, encompassing land cover types from agricultural and pasture lands to forest, savannah, and wetland systems, TWO is designed to develop comprehensive understanding of hydrological and biogeochemical processes at not only ecosystem scale, but of their spatially explicit interconnections in the landscape. In the current report, we will report the first year of ecosystem-scale fluxes of water and CO2 from the different nine sites, and discuss the regional implications of their environmental sensitivities.

Estimated Depth to Ground Water and Configuration of the Water Table in the Portland, Oregon Area

USGS Publications Warehouse

Snyder, Daniel T.

2008-01-01

Reliable information on the configuration of the water table in the Portland metropolitan area is needed to address concerns about various water-resource issues, especially with regard to potential effects from stormwater injection systems such as UIC (underground injection control) systems that are either existing or planned. To help address these concerns, this report presents the estimated depth-to-water and water-table elevation maps for the Portland area, along with estimates of the relative uncertainty of the maps and seasonal water-table fluctuations. The method of analysis used to determine the water-table configuration in the Portland area relied on water-level data from shallow wells and surface-water features that are representative of the water table. However, the largest source of available well data is water-level measurements in reports filed by well constructors at the time of new well installation, but these data frequently were not representative of static water-level conditions. Depth-to-water measurements reported in well-construction records generally were shallower than measurements by the U.S. Geological Survey (USGS) in the same or nearby wells, although many depth-to-water measurements were substantially deeper than USGS measurements. Magnitudes of differences in depth-to-water measurements reported in well records and those measured by the USGS in the same or nearby wells ranged from -119 to 156 feet with a mean of the absolute value of the differences of 36 feet. One possible cause for the differences is that water levels in many wells reported in well records were not at equilibrium at the time of measurement. As a result, the analysis of the water-table configuration relied on water levels measured during the current study or used in previous USGS investigations in the Portland area. Because of the scarcity of well data in some areas, the locations of select surface-water features including major rivers, streams, lakes, wetlands, and springs representative of where the water table is at land surface were used to augment the analysis. Ground-water and surface-water data were combined for use in interpolation of the water-table configuration. Interpolation of the two representations typically used to define water-table position - depth to the water table below land surface and elevation of the water table above a datum - can produce substantially different results and may represent the end members of a spectrum of possible interpolations largely determined by the quantity of recharge and the hydraulic properties of the aquifer. Datasets of depth-to-water and water-table elevation for the current study were interpolated independently based on kriging as the method of interpolation with parameters determined through the use of semivariograms developed individually for each dataset. Resulting interpolations were then combined to create a single, averaged representation of the water-table configuration. Kriging analysis also was used to develop a map of relative uncertainty associated with the values of the water-table position. Accuracy of the depth-to-water and water-table elevation maps is dependent on various factors and assumptions pertaining to the data, the method of interpolation, and the hydrogeologic conditions of the surficial aquifers in the study area. Although the water-table configuration maps generally are representative of the conditions in the study area, the actual position of the water-table may differ from the estimated position at site-specific locations, and short-term, seasonal, and long-term variations in the differences also can be expected. The relative uncertainty map addresses some but not all possible errors associated with the analysis of the water-table configuration and does not depict all sources of uncertainty. Depth to water greater than 300 feet in the Portland area is limited to parts of the Tualatin Mountains, the foothills of the Cascade Range, and muc

On Evaluating circulation and temperature stratification under changing water levels in Lake Mead with a 3D hydrodynamic model

NASA Astrophysics Data System (ADS)

Li, Y.; Acharya, K.; Chen, D.; Stone, M.; Yu, Z.; Young, M.; Zhu, J.; Shafer, D. S.; Warwick, J. J.

2009-12-01

Sustained drought in the western United States since 2000 has led to a significant drop (about 35 meters) in the water level of Lake Mead, the largest reservoir by volume in United States. The drought combined with rapid urban development in southern Nevada and emergence of invasive species has threatened the water quality and ecological processes in Lake Mead. A three-dimensional hydrodynamic model, Environmental Fluid Dynamics Code (EFDC), was applied to investigate lake circulation and temperature stratification in parts of Lake Mead (Las Vegas Bay and Boulder Basin) under changing water levels. Besides the inflow from Las Vegas Wash and the Colorado River, the model considered atmospheric changes as well as the boundary conditions restricted by the operation of Hoover Dam. The model was calibrated and verified by using observed data including water level, velocity, and temperature from 2003 and 2005. The model was applied to study the hydrodynamic processes at water level 366.8 m (year 2000) and at water level 338.2 m (year 2008). The high-stage simulation described the pre-drought lake hydrodynamic processes while the low-stage simulation highlighted the drawdown impact on such processes. The results showed that both inflow and wind-driven mixing process played major roles in the thermal stratification and lake circulation in both cases. However, the atmospheric boundary played a more important role than inflow temperature on thermal stratification of Lake Mead during water level decline. Further, the thermal stratification regime and flow circulation pattern in shallow lake regions (e.g.., the Boulder Basin area) were most impacted. The temperature of the lake at the high-stage was more sensitive to inflow temperatures than at low-stage. Furthermore, flow velocities decreased with the decreasing water level due to reduction in wind impacts, particularly in shallow areas of the lake. Such changes in temperature and lake current due to present drought have a strong influence on contaminant and nutrient dynamics and ecosystem of the lake.

Sea Consultants Inc, Cambridge, MA

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

Reed, D.F.

1989-06-01

The EPA is currently developing regulations to limit the radon concentration in public water supplies. Based on the latest scientific evaluations, it appears that the health impact of radon is larger than suggested by guidelines used at the state level. The radon maximum contaminant level being discussed would impact over half of the groundwater supplies in the country and a larger percentage in the New England States. In Friendship, Maine, a public water system was recently placed into operation that uses a bedrock well as a source. High radon levels are treated using granulated activated carbon contactors. Performance testing wasmore » completed that provides insight into process effectiveness and the flexibility of GAC to respond to varying loading rates. 17 refs., 5 figs., 1 tab.« less

Mercury contamination level and speciation inventory in Lakes Titicaca & Uru-Uru (Bolivia): Current status and future trends.

PubMed

Guédron, S; Point, D; Acha, D; Bouchet, S; Baya, P A; Tessier, E; Monperrus, M; Molina, C I; Groleau, A; Chauvaud, L; Thebault, J; Amice, E; Alanoca, L; Duwig, C; Uzu, G; Lazzaro, X; Bertrand, A; Bertrand, S; Barbraud, C; Delord, K; Gibon, F M; Ibanez, C; Flores, M; Fernandez Saavedra, P; Ezpinoza, M E; Heredia, C; Rocha, F; Zepita, C; Amouroux, D

2017-12-01

Aquatic ecosystems of the Bolivian Altiplano (∼3800 m a.s.l.) are characterized by extreme hydro-climatic constrains (e.g., high UV-radiations and low oxygen) and are under the pressure of increasing anthropogenic activities, unregulated mining, agricultural and urban development. We report here a complete inventory of mercury (Hg) levels and speciation in the water column, atmosphere, sediment and key sentinel organisms (i.e., plankton, fish and birds) of two endorheic Lakes of the same watershed differing with respect to their size, eutrophication and contamination levels. Total Hg (THg) and monomethylmercury (MMHg) concentrations in filtered water and sediment of Lake Titicaca are in the lowest range of reported levels in other large lakes worldwide. Downstream, Hg levels are 3-10 times higher in the shallow eutrophic Lake Uru-Uru than in Lake Titicaca due to high Hg inputs from the surrounding mining region. High percentages of MMHg were found in the filtered and unfiltered water rising up from <1 to ∼50% THg from the oligo/hetero-trophic Lake Titicaca to the eutrophic Lake Uru-Uru. Such high %MMHg is explained by a high in situ MMHg production in relation to the sulfate rich substrate, the low oxygen levels of the water column, and the stabilization of MMHg due to abundant ligands present in these alkaline waters. Differences in MMHg concentrations in water and sediments compartments between Lake Titicaca and Uru-Uru were found to mirror the offset in MMHg levels that also exist in their respective food webs. This suggests that in situ MMHg baseline production is likely the main factor controlling MMHg levels in fish species consumed by the local population. Finally, the increase of anthropogenic pressure in Lake Titicaca may probably enhance eutrophication processes which favor MMHg production and thus accumulation in water and biota. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of handheld assays for the detection of ricin and staphylococcal enterotoxin B in disinfected waters.

PubMed

Wade, Mary Margaret; Biggs, Tracey D; Insalaco, Joseph M; Neuendorff, Lisa K; Bevilacqua, Vicky L H; Schenning, Amanda M; Reilly, Lisa M; Shah, Saumil S; Conley, Edward K; Emanuel, Peter A; Zulich, Alan W

2011-01-01

Development of a rapid field test is needed capable of determining if field supplies of water are safe to drink by the warfighter during a military operation. The present study sought to assess the effectiveness of handheld assays (HHAs) in detecting ricin and Staphylococcal Enterotoxin B (SEB) in water. Performance of HHAs was evaluated in formulated tap water with and without chlorine, reverse osmosis water (RO) with chlorine, and RO with bromine. Each matrix was prepared, spiked with ricin or SEB at multiple concentrations, and then loaded onto HHAs. HHAs were allowed to develop and then read visually. Limits of detection (LOD) were determined for all HHAs in each water type. Both ricin and SEB were detected by HHAs in formulated tap water at or below the suggested health effect levels of 455 ng/mL and 4.55 ng/mL, respectively. However, in brominated or chlorinated waters, LODs for SEB increased to approximately 2,500 ng/mL. LODs for ricin increased in chlorinated water, but still remained below the suggested health effect level. In brominated water, the LOD for ricin increased to approximately 2,500 ng/mL. In conclusion, the HHAs tested were less effective at detecting ricin and SEB in disinfected water, as currently configured.

Perspectives of low cost arsenic remediation of drinking water in Pakistan and other countries.

PubMed

Malik, Amir Haider; Khan, Zahid Mehmood; Mahmood, Qaisar; Nasreen, Sadia; Bhatti, Zulfiqar Ahmed

2009-08-30

Arsenic concentrations above acceptable standards for drinking water have been detected in many countries and this should therefore is a global issue. The presence of arsenic in subsurface aquifers and drinking water systems is a potentially serious human health hazard. The current population growth in Pakistan and other developing countries will have direct bearing on the water sector for meeting the domestic, industrial and agricultural needs. Pakistan is about to exhaust its available water resources and is on the verge of becoming a water deficit country. Water pollution is a serious menace in Pakistan, as almost 70% of its surface waters as well as its groundwater reserves have contaminated by biological, organic and inorganic pollutants. In some areas of Pakistan, a number of shallow aquifers and tube wells are contaminated with arsenic at levels which are above the recommended USEPA arsenic level of 10 ppb (10 microg L(-1)). Adverse health effects including human mortality from drinking water are well documented and can be attributed to arsenic contamination. The present paper reviews appropriate and low cost methods for the elimination of arsenic from drinking waters. It is recommended that a combination of low cost chemical treatment like ion exchange, filtration and adsorption along with bioremediation may be useful option for arsenic removal from drinking water.

Impacts of Sea-Level Rise and Human Activity on a Tropical Continental Shelf, RN State, NE Brazil

NASA Astrophysics Data System (ADS)

Vital, H.; Barros Pereira, T. R.; Lira, H. F.; Tabosa, W. F.; Eichler, P.; Stattegger, K.; Sen Gupta, B. K.; Gomes, M. P.; Nogueira, M. L. D. S.; Pierri, G. C. S.

2014-12-01

The northeastern Brazilian, tropical coast-shelf system along the Atlantic Ocean is a sediment-starved zone, because of low relief, small drainage basins, and a semiarid climate. This work presents the major results of a study of environmental changes, particularly those related to Holocene sea-level rise, affecting the coast and shallow waters of Rio Grande do Norte (RN) State, NE Brazil. The methods included bottom-sediment characterization, bioindicator tracking, and integrated shallow-water geophysical investigation. This coastline is marked by active sea cliffs carved into tablelands alternating with reef- or dune-barrier sections, beach rocks and lagoons, whereas the shelf is a narrow, very shallow, and highly energetic system. Overall, the area is under the natural influence of tides (with a semidiurnal mesotidal regime) and the anthropogenic influence of salt exploration, oil industry, shrimp farms, tourism, and wind-farms. Sedimentation during the Holocene has been controlled mainly by sea-level variation, longshore currents, and the advance and westward propagation of active dunes along the coast. As in other areas around the world, growing numbers of permanent and seasonal residents choose to live at or near the ocean. Coastal erosion is a cause for concern along many Brazilian beaches, and several erosion hot spots are already recognized in RN State. Curves of Holocene relative sea-level variation were established for RN State, but the absence of long-term oceanographic observations in the last centuries or that of detailed altimetry maps hinders the evaluation of different risk scenarios at the local level. Nevertheless, impacts of the current sea-level rise and human activity can be observed along the RN coastal-shelf system. Particular aspects of the study, such as oil-spill monitoring, coastal-water sewage contamination, and coastal erosion, will be highlighted.

Isotonic transport by the Na+-glucose cotransporter SGLT1 from humans and rabbit

PubMed Central

Zeuthen, T; Meinild, A-K; Loo, D D F; Wright, E M; Klaerke, D A

2001-01-01

In order to study its role in steady state water transport, the Na+-glucose cotransporter (SGLT1) was expressed in Xenopus laevis oocytes; both the human and the rabbit clones were tested. The transport activity was monitored as a clamp current and the flux of water followed optically as the change in oocyte volume. SGLT1 has two modes of water transport. First, it acts as a molecular water pump: for each 2 Na+ and 1 sugar molecule 264 water molecules were cotransported in the human SGLT1 (hSGLT1), 424 for the rabbit SGLT1 (rSGLT1). Second, it acts as a water channel. The cotransport of water was tightly coupled to the sugar-induced clamp current. Instantaneous changes in clamp current induced by changes in clamp voltage were accompanied by instantaneous changes in the rate of water transport. The cotransported solution was predicted to be hypertonic, and an osmotic gradient built up across the oocyte membrane with continued transport; this resulted in an additional osmotic influx of water. After 5-10 min a steady state was achieved in which the total influx was predicted to be isotonic with the intracellular solution. With the given expression levels, the steady state water transport was divided about equally between cotransport, osmosis across the SGLT1 and osmosis across the native oocyte membrane. Coexpression of AQP1 with the SGLT1 increased the water permeability more than 10-fold and steady state isotonic transport was achieved after less than 2 s of sugar activation. One-third of the water was cotransported, and the remainder was osmotically driven through the AQP1. The data suggest that SGLT1 has three roles in isotonic water transport: it cotransports water directly, it supplies a passive pathway for osmotic water transport, and it generates an osmotic driving force that can be employed by other pathways, for example aquaporins. PMID:11251046

Water data in US: a spatial, temporal and sectoral analysis

NASA Astrophysics Data System (ADS)

Josset, L.; Allaire, M.; Rising, J. A.; Thomas, C.; Lall, U.

2017-12-01

Water data plays a crucial role in the development and implementation of sustainable water management strategies. Both effective design and assessment hinge on accurate information. This requires environmental, climatic, hydrologic, hydrogeologic, industrial, agricultural, energetic and socio-economic data to accurately characterize and project future supply and demand. In 2001, Vorosmarty et al. painted a stark future for water data, which was qualified as ``a new endangered species". Sixteen years after this publication, we propose a review of the current state of water data in the United States. While considerable progress has been made in data science and model development in the recent years, models are only as good as the data that populate them. After a brief overview of water data aggregated at the national level, we compare datasets from federal agencies with water information collected by individual states. We note in particular the potential gaps in the collected information that would support research beyond water balance accounts to informing regulations, investments, and economic decisions. In addition, we assess the information structures that host and disseminate data as well as data availability and usability (i.e. whether tools are proposed such as metrics, visualization, projections). We conclude our paper with a review of the current technological developments, policies and initiatives that may be transformative and redefine the future of water data. We follow two angles: the progress made in data collection (e.g. remote sensing, datascience, reporting policies) and in data dissemination (frameworks, cyber-infrastructures and standards). We review in particular the current initiatives taking place in US and around the world that promote water data freely available to all.

Two Virus Based Endocrine Disruptor Assays Effective Across Vertebrate Classes.

EPA Science Inventory

The presence of hormone mimics, or endocrine disrupting compounds (EDC’s), in the environment are increasing. Sources range from agricultural run–off, pharmaceuticals in waste water, to industrial operations. Current levels of contamination are sufficient to alter sexual develo...

Underwater noise reduction of marine pile driving using a double pile.

DOT National Transportation Integrated Search

2015-12-01

Impact pile driving of steel piles in marine environments produces extremely high sound levels in the water. : It has been shown that current pile driving noise attenuation techniques, such as bubble curtains and : cofferdams, provide limited noise r...

Hydrology of Polk County, Florida

USGS Publications Warehouse

Spechler, Rick M.; Kroening, Sharon E.

2007-01-01

Local water managers usually rely on information produced at the State and regional scale to make water-resource management decisions. Current assessments of hydrologic and water-quality conditions in Polk County, Florida, commonly end at the boundaries of two water management districts (South Florida Water Management District and the Southwest Florida Water Management District), which makes it difficult for managers to determine conditions throughout the county. The last comprehensive water-resources assessment of Polk County was published almost 40 years ago. To address the need for current countywide information, the U.S. Geological Survey began a 3?-year study in 2002 to update information about hydrologic and water-quality conditions in Polk County and identify changes that have occurred. Ground-water use in Polk County has decreased substantially since 1965. In 1965, total ground-water withdrawals in the county were about 350 million gallons per day. In 2002, withdrawals totaled about 285 million gallons per day, of which nearly 95 percent was from the Floridan aquifer system. Water-conservation practices mainly related to the phosphate-mining industry as well as the decrease in the number of mines in operation in Polk County have reduced total water use by about 65 million gallons per day since 1965. Polk County is underlain by three principal hydrogeologic units. The uppermost water-bearing unit is the surficial aquifer system, which is unconfined and composed primarily of clastic deposits. The surficial aquifer system is underlain by the intermediate confining unit, which grades into the intermediate aquifer system and consists of up to two water-bearing zones composed of interbedded clastic and carbonate rocks. The lowermost hydrogeologic unit is the Floridan aquifer system. The Floridan aquifer system, a thick sequence of permeable limestone and dolostone, consists of the Upper Floridan aquifer, a middle semiconfining unit, a middle confining unit, and the Lower Floridan aquifer. The Upper Floridan aquifer provides most of the water required to meet demand in Polk County. Data from about 300 geophysical and geologic logs were used to construct hydrogeologic maps showing the tops and thicknesses of the aquifers and confining units within Polk County. Thickness of the surficial aquifer system ranges from several feet thick or less in the extreme northwestern part of the county and along parts of the Peace River south of Bartow to more than 200 feet along the southern part of the Lake Wales Ridge in eastern Polk County. Thickness of the intermediate aquifer system/intermediate confining unit is highly variable throughout the county because of past erosional processes and sinkhole formation. Thickness of the unit ranges from less than 25 feet in the extreme northwestern part of the county to more than 300 feet in southwestern Polk County. The altitude of the top of the Upper Floridan aquifer in the county ranges from about 50 feet above National Geodetic Vertical Datum of 1929 (NGVD 29) in the northwestern part to more than 250 feet below NGVD 29 in the southern part. Water levels in the Upper Floridan aquifer fluctuate seasonally, increasing during the wet season (June through September) and decreasing during the rest of the year. Water levels in the Upper Floridan aquifer also can change from year to year, depending on such factors as pumpage and climatic variations. In the southwestern part of the county, fluctuations in water use related to phosphate mining have had a major impact on ground-water levels. Hydrographs of selected wells in southwestern Polk County show a general decline in water levels that ended in the mid-1970s. This water-level decline coincides with an increase in water use associated with phosphate mining. A substantial increase in water levels that began in the mid-1970s coincides with a period of decreasing water use in the county. Despite reductions in water use since 1970, howev

Flood-inundation maps for the Wabash River at Lafayette, Indiana

USGS Publications Warehouse

Kim, Moon H.

2018-05-10

Digital flood-inundation maps for an approximately 4.8-mile reach of the Wabash River at Lafayette, Indiana (Ind.) were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science web site at https://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at USGS streamgage 03335500, Wabash River at Lafayette, Ind. Current streamflow conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the internet at https://waterdata.usgs.gov/in/nwis/uv?site_no=03335500. In addition, information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood-warning system (https://water.weather.gov/ahps/). The NWS AHPS forecasts flood hydrographs at many places that are often colocated with USGS streamgages, including the Wabash River at Lafayette, Ind. NWS AHPS-forecast peak-stage information may be used with the maps developed in this study to show predicted areas of flood inundation.For this study, flood profiles were computed for the Wabash River reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relations at USGS streamgage 03335500, Wabash River at Lafayette, Ind., and high-water marks from the flood of July 2003 (U.S. Army Corps of Engineers [USACE], 2007). The calibrated hydraulic model was then used to determine 23 water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the highest stage of the current stage-discharge rating curve. The simulated water-surface profiles were then combined with a geographic information system digital elevation model derived from light detection and ranging to delineate the area flooded at each water level. The availability of these maps, along with internet information regarding current stage from the USGS streamgage 03335500, Wabash River at Lafayette, Ind., and forecasted high-flow stages from the NWS AHPS, will provide emergency management personnel and residents with information that is critical for flood-response activities such as evacuations and road closures, and for postflood recovery efforts.

Flood-inundation maps for the North Branch Elkhart River at Cosperville, Indiana

USGS Publications Warehouse

Kim, Moon H.; Johnson, Esther M.

2014-01-01

Digital flood-inundation maps for a reach of the North Branch Elkhart River at Cosperville, Indiana (Ind.), were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Army Corps of Engineers, Detroit District. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at USGS streamgage 04100222, North Branch Elkhart River at Cosperville, Ind. Current conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/in/nwis/uv?site_no=04100222. In addition, information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http:/water.weather.gov/ahps/). The NWS AHPS forecasts flood hydrographs at many places that are often colocated with USGS streamgages, including the North Branch Elkhart River at Cosperville, Ind. NWS AHPS-forecast peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. For this study, flood profiles were computed for the North Branch Elkhart River reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relations at USGS streamgage 04100222, North Branch Elkhart River at Cosperville, Ind., and preliminary high-water marks from the flood of March 1982. The calibrated hydraulic model was then used to determine four water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the highest stage of the current stage-discharge rating curve. The simulated water-surface profiles were then combined with a geographic information system (GIS) digital elevation model (DEM, derived from Light Detection and Ranging [LiDAR]) in order to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage 04100222, North Branch Elkhart River at Cosperville, Ind., and forecast stream stages from the NWS AHPS, provides emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

Solutions Network Formulation Report. Improving NOAA's Tides and Currents Through Enhanced Data Inputs from NASA's Ocean Surface Topography Mission

NASA Technical Reports Server (NTRS)

Guest, DeNeice C.

2006-01-01

The Nation uses water-level data for a variety of practical purposes, including hydrography, nautical charting, maritime navigation, coastal engineering, and tsunami and storm surge warnings (NOAA, 2002; Digby et al., 1999). Long-term applications include marine boundary determinations, tidal predictions, sea-level trend monitoring, oceanographic research, and climate research. Accurate and timely information concerning sea-level height, tide, and ocean current is needed to understand their impact on coastal management, disaster management, and public health. Satellite altimeter data products are currently used by hundreds of researchers and operational users to monitor ocean circulation and to improve scientists understanding of the role of the oceans in climate and weather. The NOAA (National Oceanic and Atmospheric Administration) National Ocean Service has been monitoring sea-level variations for many years (NOAA, 2006). NOAA s Tides & Currents DST (decision support tool, managed by the Center for Operational Oceanographic Products and Services, is the portal to a vast collection of oceanographic and meteorological data (historical and real-time), predictions, and nowcasts and forecasts. This report assesses the capacity of NASA s satellite altimeter data to meet societal decision support needs through incorporation into NOAA s Tides & Currents.

Infantile methemoglobinemia: reexamining the role of drinking water nitrates.

PubMed Central

Avery, A A

1999-01-01

Ingestion of nitrates in drinking water has long been thought to be a primary cause of acquired infantile methemoglobinemia, often called blue baby syndrome. However, recent research and a review of historical cases offer a more complex picture of the causes of infantile methemoglobinemia. Gastrointestinal infection and inflammation and the ensuing overproduction of nitric oxide may be the cause of many cases of infantile methemoglobinemia previously attributed to drinking water nitrates. If so, current limits on allowable levels of nitrates in drinking water, which are based solely on the health threat of infantile methemoglobinemia, may be unnecessarily strict. Images Figure 1 Figure 2 PMID:10379005

An expanded model: flood-inundation maps for the Leaf River at Hattiesburg, Mississippi, 2013

USGS Publications Warehouse

Storm, John B.

2014-01-01

Digital flood-inundation maps for a 6.8-mile reach of the Leaf River at Hattiesburg, Mississippi (Miss.), were created by the U.S. Geological Survey (USGS) in cooperation with the City of Hattiesburg, City of Petal, Forrest County, Mississippi Emergency Management Agency, Mississippi Department of Homeland Security, and the Emergency Management District. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage at Leaf River at Hattiesburg, Miss. (station no. 02473000). Current conditions for estimating near-real-time areas of inundation by use of USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/. In addition, the information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that are often colocated with USGS streamgages. NWS-forecasted peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relations at the Leaf River at Hattiesburg, Miss. streamgage (02473000) and documented high-water marks from recent and historical floods. The hydraulic model was then used to determine 13 water-surface profiles for flood stages at 1.0-foot intervals referenced to the streamgage datum and ranging from bankfull to approximately the highest recorded water level at the streamgage. The simulated water-surface profiles were then combined with a geographic information system (GIS) digital elevation model (DEM, derived from light detection and ranging (lidar) data having a 0.6-foot vertical and 9.84-foot horizontal resolution) in order to delineate the area flooded at each water level. Development of the estimated flood inundation maps as described in this report update previously published inundation estimates by including reaches of the Bouie and Leaf Rivers above their confluence. The availability of these maps along with Internet information regarding current stage from USGS streamgages and forecasted stream stages from the NWS provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures as well as for post flood recovery efforts.

Ocean-Ice-Atmosphere Interactions off Sabrina and Adelie Coasts During NBP1402 and AU1402

NASA Astrophysics Data System (ADS)

Orsi, A. H.; Zielinski, N. J.; Webb, C.; Huber, B. A.

2015-12-01

Diverse interactions of winds, currents and ice around Antarctica dictate how, where and when the world's densest waters form, massive floating ice shelves and glaciers melt, gases are exchanged at the sea surface, and primary productivity. Compelled by recent rate estimates of East Antarctic Ice Sheet mass loss, we contrast the paths and mixing histories of oceanic waters reaching the continental ice edge off the Sabrina and Adelie coasts relying on a the first synoptic shipboard measurements made by U.S. (NBP1402) and Australian (AU1402) scientists. Analysis of historical hydrography and sea ice concentration fields within the Mertz Polynya indicates the apparent effect of evolving ocean-ice- atmosphere interactions on the characteristics of local Shelf Water (SW) sources. A polynya dominated water mass structure similar to that observed off the Adelie Coast before the removal of the Mertz Ice Tongue was expected to the west of the Dalton Ice Tongue (DIT). However, there was no evidence of dense SW off Sabrina Coast during both summer cruises of 2014 and 2015, thus lessening the region's preconceived influence to global meridional overturning. Present sea ice production within the eastern Dalton Polynya is overshadowed by freshwater input to relatively stable interior upper waters. The Antarctic Coastal Current (ACoC) picks up distinct meltwater contributions along the DIT western flank and in front of the Moscow University Ice Shelf (MUIS) and Totten Glacier (TG). Unlike over other highly influential margins to global sea level rise, the main evidence of inflow and mixing of relatively warm oceanic waters is reduced to relatively cold thermocline water (< 0.3°C) from the continental slope. This source water enters the eastern trough off Sabrina Coast and is swiftly steered poleward by complex underlying topography. Meltwater export from beneath the MUIS and TG is observed at newly discovered trenches that effectively constrain sub-cavity inflow to low salinity near-freezing waters drawn from intermediate levels of the adjacent westward flowing ACoC.
Winds, currents and ice interactions observed off Sabrina Coast during NBP1402 and AU1402 are most likely widespread, in view of reported decadal freshening of upper waters over the Antarctic continental shelf and their localized AABW outflows.

Effects of Shampoo and Water Washing on Hair Cortisol Concentrations

PubMed Central

Hamel, Amanda F.; Meyer, Jerrold S.; Henchey, Elizabeth; Dettmer, Amanda M.; Suomi, Stephen J.; Novak, Melinda A.

2010-01-01

Background Measurement of cortisol in hair is an emerging biomarker for chronic stress in human and nonhuman primates. Currently unknown, however, is the extent of potential cortisol loss from hair that has been repeatedly exposed to shampoo and/or water. Methods Pooled hair samples from 20 rhesus monkeys were subjected to five treatment conditions: 10, 20, or 30 shampoo washes, 20 water-only washes, or a no-wash control. For each wash, hair was exposed to a dilute shampoo solution or tap water for 45 s, rinsed 4 times with tap water, and rapidly dried. Samples were then processed for cortisol extraction and analysis using previously published methods. Results Hair cortisol levels were significantly reduced by washing, with an inverse relationship between number of shampoo washes and the cortisol concentration. This effect was mainly due to water exposure, as cortisol levels following 20 water-only washes were similar to those following 20 shampoo treatments. Conclusions Repeated exposure to water with or without shampoo appears to leach cortisol from hair, yielding values that underestimate the amount of chronic hormone deposition within the shaft. Collecting samples proximal to the scalp and obtaining hair washing frequency data may be valuable when conducting human hair cortisol studies. PMID:21034727

Estimating the potential water reuse based on fuzzy reasoning.

PubMed

Almeida, Giovana; Vieira, José; Marques, Alfeu Sá; Kiperstok, Asher; Cardoso, Alberto

2013-10-15

Studies worldwide suggest that the risk of water shortage in regions affected by climate change is growing. Decision support tools can help governments to identify future water supply problems in order to plan mitigation measures. Treated wastewater is considered a suitable alternative water resource and it is used for non-potable applications in many dry regions around the world. This work describes a decision support system (DSS) that was developed to identify current water reuse potential and the variables that determine the reclamation level. The DSS uses fuzzy inference system (FIS) as a tool and multi-criteria decision making is the conceptual approach behind the DSS. It was observed that water reuse level seems to be related to environmental factors such as drought, water exploitation index, water use, population density and the wastewater treatment rate, among others. A dataset was built to analyze these features through water reuse potential with a FIS that considered 155 regions and 183 cities. Despite some inexact fit between the classification and simulation data for agricultural and urban water reuse potential it was found that the FIS was suitable to identify the water reuse trend. Information on the water reuse potential is important because it issues a warning about future water supply needs based on climate change scenarios, which helps to support decision making with a view to tackling water shortage. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Sparta aquifer in Arkansas' critical ground-water areas: Response of the aquifer to supplying future water needs

USGS Publications Warehouse

Hays, Phillip D.; Fugitt, D. Todd

1999-01-01

The Sparta aquifer is a confined aquifer of great regional importance that comprises a sequence of unconsolidated sand, silt, and clay units extending across much of eastern and southeastern Arkansas and into adjoining States. Water use from the aquifer has doubled since 1975 and continues to increase, and large water-level declines are occurring in many areas of the aquifer. To focus State attention and resources on the growing problem and to provide a mechanism for locally based education and management, the Arkansas Soil and Water Conservation Commission has designated Critical Ground-Water Areas in some counties (see page 6, ?What is a Critical Ground-Water Area??). Ground-water modeling study results show that the aquifer cannot continue to meet growing water-use demands. Dewatering of the primary producing sands is predicted to occur within 10 years in some areas if current trends continue. The predicted dewatering will cause reduced yields and damage the aquifer. Modeling also shows that a concerted ground-water conservation management plan could enable sustainable use of the aquifer. Water-conservation measures and use of alternative sources that water managers in Union County (an area of high demand and growth in Arkansas' initial five-county Critical Ground-Water Area) think to be realistic options result in considerable recovery in water levels in the aquifer during a 30-year model simulation.

Thermo-hydrological and chemical (THC) modeling to support Field Test Design

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

Stauffer, Philip H.; Jordan, Amy B.; Harp, Dylan Robert

This report summarizes ongoing efforts to simulate coupled thermal-hydrological-chemical (THC) processes occurring within a hypothetical high-level waste (HLW) repository in bedded salt. The report includes work completed since the last project deliverable, “Coupled model for heat and water transport in a high level waste repository in salt”, a Level 2 milestone submitted to DOE in September 2013 (Stauffer et al., 2013). Since the last deliverable, there have been code updates to improve the integration of the salt module with the pre-existing code and development of quality assurance (QA) tests of constitutive functions and precipitation/dissolution reactions. Simulations of bench-scale experiments, bothmore » historical and currently in the planning stages have been performed. Additional simulations have also been performed on the drift-scale model that incorporate new processes, such as an evaporation function to estimate water vapor removal from the crushed salt backfill and isotopic fractionation of water isotopes. Finally, a draft of a journal paper on the importance of clay dehydration on water availability is included as Appendix I.« less

Annual summary of ground-water conditions in Arizona, Spring 1981 to Spring 1982

USGS Publications Warehouse

,

1982-01-01

The withdrawal of ground water was about 5.4 million acre-feet in Arizona in 1981, which is about 800,000 acre-feet more than the amount withdrawn in 1980. Most of the increase in 1981 was in the amount of ground water used for irrigation in the Basin and Range lowlands province. Through 1981, slightly more than 189 million acre-feet of ground water had been withdrawn from the ground-water reservoirs in Arizona. The report contains two small-scale maps that show ground-water pumpage by areas and the status of the ground-water inventory in the State. The main map, which is at a scale of 1:500,000, shows potential well production, depth to water in selected wells in spring 1982, and change in water level in selected wells from 1977 to 1982. A brief text summarizes the current ground-water conditions in the State. (USGS)

Does water hardness have preventive effect on cardiovascular disease?

PubMed

Momeni, Mitra; Gharedaghi, Zahra; Amin, Mohammad Mehadi; Poursafa, Parinaz; Mansourian, Marjan

2014-02-01

The aim of this study is to investigate the association of calcium and magnesium concentration of drinking water with cardiovascular disease (CVDs) in urban and rural areas of a city in Iran. This case-control study was conducted in 2012 in Khansar County in Isfahan province, Iran. We used the official data of the Provincial health center regarding the chemical analysis data of urban and rural areas including the hardness, calcium and magnesium content of drinking water. Data of patients hospitalized for CVD in the only specialty hospital of the city was gathered for the years of 2010 and 2011. In 2010, water calcium content above 72 mg/L was associated with reduced number of CVDs in 1000 population; whereas in 2011 this decrease in CVDs was observed for calcium levels of more than 75 mg/L. In 2010, the level of water Mg content ranged from 23 to 57 mg/L. By increasing Mg hardness level above 31 mg/L in 2010 and above 26 mg/L in 2011 were associated with decreased number of CVDs in 1000 people. decrease. Our study suggests favorable protective effects of water hardness, mainly water magnesium content, on CVDs. Water hardness, as well as calcium and magnesium content of drinking water may have a protective role against CVDs. Further experimental studies are necessary to determine the underlying mechanisms and longitudinal studies are required to study the clinical impacts of the current findings.

The effect of the Environmental Protection Agency maximum contaminant level on arsenic exposure in the USA from 2003 to 2014: an analysis of the National Health and Nutrition Examination Survey (NHANES).

PubMed

Nigra, Anne E; Sanchez, Tiffany R; Nachman, Keeve E; Harvey, David; Chillrud, Steven N; Graziano, Joseph H; Navas-Acien, Ana

2017-11-01

The current US Environmental Protection Agency (EPA) maximum contaminant level (MCL) for arsenic in public water systems (10 µg/L) took effect in 2006. Arsenic is not federally regulated in private wells. The impact of the 2006 MCL on arsenic exposure in the US, as confirmed through biomarkers, is presently unknown. We evaluated national trends in water arsenic exposure in the US, hypothesizing that urinary arsenic levels would decrease over time among participants using public water systems but not among those using well water. We further estimated the expected number of avoided lung, bladder, and skin cancer cases. We evaluated 14,127 participants in the National Health and Nutrition Examination Survey (NHANES) 2003-2014 with urinary dimethylarsinate (DMA) and total arsenic available. To isolate water exposure, we expanded a residual-based method to remove tobacco and dietary contributions of arsenic. We applied EPA risk assessment approaches to estimate the expected annual number of avoided cancer cases comparing arsenic exposure in 2013-2014 vs. 2003-2004. Among public water users, fully adjusted geometric means (GMs) of DMA decreased from 3.01 µg/L in 2003-2004 to 2.49 µg/L in 2013-2014 (17% reduction; 95% confidence interval 10%, 24%; p-trend<0.01); no change was observed among well water users (p-trend= 0.35). Assuming these estimated exposure reductions will remain similar across a lifetime, we estimate a reduction of 200 to 900 lung and bladder cancer cases per year depending on the approach used. The decline in urinary arsenic among public water but not private well users in NHANES 2003-2014 indicates that the implementation of the current MCL has reduced arsenic exposure in the US population. Our study supports prior work showing that well water users are inadequately protected against drinking water arsenic, and confirms the critical role of federal drinking water regulations in reducing toxic exposures and protecting human health. This work was supported by the National Institute of Environmental Health Sciences (1R01ES025216, R01ES021367, 5P30ES009089 and P42ES010349). A. E. Nigra was supported by 5T32ES007322.

Hydrogeology and Simulation of Groundwater Flow in the Plymouth-Carver-Kingston-Duxbury Aquifer System, Southeastern Massachusetts

USGS Publications Warehouse

Masterson, John P.; Carlson, Carl S.; Walter, Donald A.; Other contributing authors: Bent, Gardner C.; Massey, Andrew J.

2009-01-01

The glacial sediments that underlie the Plymouth-Carver-Kingston-Duxbury area of southeastern Massachusetts compose an important aquifer system that is the primary source of water for a region undergoing rapid development. Population increases and land-use changes in this area has led to two primary environmental effects that relate directly to groundwater resources: (1) increases in pumping that can adversely affect environmentally sensitive groundwater-fed surface waters, such as ponds, streams, and wetlands; and (2) adverse effects of land use on the quality of water in the aquifer. In response to these concerns, the U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, began an investigation in 2005 to improve the understanding of the hydrogeology in the area and to assess the effects of changing pumping and recharge conditions on groundwater flow in the Plymouth-Carver-Kingston-Duxbury aquifer system. A numerical flow model was developed based on the USGS computer program MODFLOW-2000 to assist in the analysis of groundwater flow. Model simulations were used to determine water budgets, flow directions, and the sources of water to pumping wells, ponds, streams, and coastal areas. Model-calculated water budgets indicate that approximately 298 million gallons per day (Mgal/d) of water recharges the Plymouth-Carver-Kingston-Duxbury aquifer system. Most of this water (about 70 percent) moves through the aquifer, discharges to streams, and then reaches the coast as surface-water discharge. Of the remaining 30 percent of flow, about 25 percent of the water that enters the aquifer as recharge discharges directly to coastal areas and 5 percent discharges to pumping wells. Groundwater withdrawals are anticipated to increase from the current (2005) rate of about 14 Mgal/d to about 21 Mgal/d by 2030. Pumping from large-capacity production wells decreases water levels and increases the potential for effects on surface-water bodies, which are affected by pumping and wastewater disposal locations and rates. Pumping wells that are upgradient of surface-water bodies potentially capture water that would otherwise discharge to these surface-water bodies, thereby reducing streamflow and pond levels. The areas most affected by proposed increases in groundwater withdrawals are in the Towns of Plymouth and Wareham where more than half of the proposed increase in pumping will occur. In response to an increase of about 7 Mgal/d of pumping, groundwater discharge to streams is reduced by about 6 cubic feet per second (ft3/s) (about 4 Mgal/d) from a total of about 325 ft3/s. Reduction in streamflow is moderated by an increase of artificial recharge from wastewater returned to the aquifer by onsite domestic septic systems and centralized wastewater treatment facilities. It is anticipated that about 3 Mgal/d of the 7 Mgal/d of increase in pumped water will be returned to the aquifer as wastewater by 2030. Currently (2005) about 3 percent of groundwater discharge to streams is from wastewater return flow to the aquifer during average conditions. During drought conditions, the component of streamflow augmented by wastewater return flow doubles as wastewater recharge remains constant and aquifer recharge rates decrease. Wastewater return flow, whether as direct groundwater discharge to streams or as an additional source of aquifer recharge, increases the height of the water table near streams, thereby moderating the effects of increased groundwater withdrawals on streamflow. An analysis of a simulated drought similar to the 1960s drought of record indicates that the presence of streams moderates the effects on water levels of reduced aquifer recharge. The area where water-table altitudes were least affected by drought was in the Weweantic River watershed in the Town of Carver. Water levels decreased by less than 2 feet from current average conditions compared to decreases of greater than 5

Effect of suppressor current intensity on the determination of glyphosate and aminomethylphosphonic acid by suppressed conductivity ion chromatography.

PubMed

Dimitrakopoulos, Ioannis K; Thomaidis, Nikolaos S; Megoulas, Nikolaos C; Koupparis, Michael A

2010-05-28

This paper presents the application of ion chromatography with electrolytic eluent generation and mobile phase suppression for the direct conductimetric detection of glyphosate and its degradation product aminomethylphosphonic acid (AMPA). The compounds were separated on a Dionex AS18 anion exchange column with a 12-40 mM KOH step gradient from 9 to 9.5 min. The effect of the suppressor current intensity on the electrostatic interaction of these amphoteric compounds with the suppressor cation exchange membranes was evaluated. A suppressor current gradient technique was proposed for the limitation of peak broadening and baseline noise, in order to improve method sensitivity and detectability. It was observed that residual sample carbonates co-eluted with AMPA when a large injection loop was installed for the low level determination of both compounds in natural waters. For this reason, glyphosate was isocratically eluted using 33 mM KOH in order to decrease analysis time within 10 min and a column clean up step using 100 mM KOH was used to ensure retention time reproducibility. The developed method was applied to the analysis of drinking and natural water and it was further successfully applied to orange samples with slight modifications. Instrumental LOD for glyphosate was 0.24 microg/L, while method LOD was 0.54 microg/L for spring waters and 0.01 mg/kg for oranges using a 1000 microL direct loop injection of the sample. Intra-day and inter-day precision (as %RSD) for water samples was 4.6% and 12% at a spiking level of 2 microg/L, and the recovery ranged from 64% to 88% depending on sample conductivity. For orange samples, the inter-day precision was 1.4% at a spiking level of 4.4 mg/kg, while overall recovery was 103%. The developed method is direct, fast, sensitive and relatively inexpensive, and could be used as an ideal fast screening tool for the monitoring of glyphosate residues in water and fruit samples. Copyright 2010 Elsevier B.V. All rights reserved.

Microelectrode-based technology for the detection of low levels of bacteria

NASA Technical Reports Server (NTRS)

Rogers, Tom D.; Hitchens, G. D.; Mishra, S. K.; Pierson, D. L.

1992-01-01

A microelectrode-based electrochemical detection method was used for quantitation of bacteria in water samples. The redox mediator, benzoquinone, was used to accept electrons from the bacterial metabolic pathway to create a flow of electrons by reducing the mediator. Electrochemical monitoring electrodes detected the reduced mediator as it diffused out of the cells and produced a small electrical current. By using a combination of microelectrodes and monitoring instrumentation, the cumulative current generated by a particular bacterial population could be monitored. Using commercially available components, an electrochemical detection system was assembled and tested to evaluate its potential as an emerging technology for rapid detection and quantitation of bacteria in water samples.

Small Microbial Three-Electrode Cell Based Biosensor for Online Detection of Acute Water Toxicity.

PubMed

Yu, Dengbin; Zhai, Junfeng; Liu, Changyu; Zhang, Xueping; Bai, Lu; Wang, Yizhe; Dong, Shaojun

2017-11-22

The monitoring of toxicity of water is very important to estimate the safety of drinking water and the level of water pollution. Herein, a small microbial three-electrode cell (M3C) biosensor filled with polystyrene particles was proposed for online monitoring of the acute water toxicity. The peak current of the biosensor related with the performance of the bioanode was regarded as the toxicity indicator, and thus the acute water toxicity could be determined in terms of inhibition ratio by comparing the peak current obtained with water sample to that obtained with nontoxic standard water. The incorporation of polystyrene particles in the electrochemical cell not only reduced the volume of the samples used, but also improved the sensitivity of the biosensor. Experimental conditions including washing time with PBS and the concentration of sodium acetate solution were optimized. The stability of the M3C biosensor under optimal conditions was also investigated. The M3C biosensor was further examined by formaldehyde at the concentration of 0.01%, 0.03%, and 0.05% (v/v), and the corresponding inhibition ratios were 14.6%, 21.6%, and 36.4%, respectively. This work provides a new insight into the development of an online toxicity detector based on M3C biosensor.

Dynamic characteristics of corona discharge generated under rainfall condition on AC charged conductors

NASA Astrophysics Data System (ADS)

Xu, Pengfei; Zhang, Bo; Wang, Zezhong; Chen, Shuiming; He, Jinliang

2017-12-01

By synchronous measurement of corona current and the water droplet deformation process on a conductor surface, different types of corona discharge are visualized when AC voltage is applied on a line-ground electrode system. The corona characteristics are closely related to the applied voltage and water supply rate. With the increase of AC voltage, the positive Taylor cone discharge firstly appears and then disappears, replaced by the dripping and crashing discharge. Furthermore, the number of pulses in each pulse train increases with the increase of applied voltage. The mechanism of the transfer from the positive Taylor cone discharge to the dripping and crashing discharge is found to be related to the oscillation process of the water droplet. The water supply rate also has a great influence on the characteristics of corona currents. The number of positive pulse trains increases linearly when the water supply rate gets larger, leading to a higher audible noise and radio interference level from the AC corona, which is quite different from that of the DC corona. The difference between the AC and DC coronas under rainfall conditions is analyzed finally.

A blue/green water-based accounting framework for assessment of water security

NASA Astrophysics Data System (ADS)

Rodrigues, Dulce B. B.; Gupta, Hoshin V.; Mendiondo, Eduardo M.

2014-09-01

A comprehensive assessment of water security can incorporate several water-related concepts, while accounting for Blue and Green Water (BW and GW) types defined in accordance with the hydrological processes involved. Here we demonstrate how a quantitative analysis of provision probability and use of BW and GW can be conducted, so as to provide indicators of water scarcity and vulnerability at the basin level. To illustrate the approach, we use the Soil and Water Assessment Tool (SWAT) to model the hydrology of an agricultural basin (291 km2) within the Cantareira Water Supply System in Brazil. To provide a more comprehensive basis for decision making, we analyze the BW and GW-Footprint components against probabilistic levels (50th and 30th percentile) of freshwater availability for human activities, during a 23 year period. Several contrasting situations of BW provision are distinguished, using different hydrological-based methodologies for specifying monthly Environmental Flow Requirements (EFRs), and the risk of natural EFR violation is evaluated by use of a freshwater provision index. Our results reveal clear spatial and temporal patterns of water scarcity and vulnerability levels within the basin. Taking into account conservation targets for the basin, it appears that the more restrictive EFR methods are more appropriate than the method currently employed at the study basin. The blue/green water-based accounting framework developed here provides a useful integration of hydrologic, ecosystem and human needs information on a monthly basis, thereby improving our understanding of how and where water-related threats to human and aquatic ecosystem security can arise.

Health-based ingestion exposure guidelines for Vibrio cholerae: Technical basis for water reuse applications.

PubMed

Watson, Annetta P; Armstrong, Anthony Q; White, George H; Thran, Brandolyn H

2018-02-01

U.S. military and allied contingency operations are increasingly occurring in locations with limited, unstable or compromised fresh water supplies. Non-potable graywater reuse is currently under assessment as a viable means to increase mission sustainability while significantly reducing the resources, logistics and attack vulnerabilities posed by transport of fresh water. Development of health-based (non-potable) exposure guidelines for the potential microbial components of graywater would provide a logical and consistent human-health basis for water reuse strategies. Such health-based strategies will support not only improved water security for contingency operations, but also sustainable military operations. Dose-response assessment of Vibrio cholerae based on adult human oral exposure data were coupled with operational water exposure scenario parameters common to numerous military activities, and then used to derive health risk-based water concentrations. The microbial risk assessment approach utilized oral human exposure V. cholerae dose studies in open literature. Selected studies focused on gastrointestinal illness associated with experimental infection by specific V. cholerae serogroups most often associated with epidemics and pandemics (O1 and O139). Nonlinear dose-response model analyses estimated V. cholerae effective doses (EDs) aligned with gastrointestinal illness severity categories characterized by diarrheal purge volume. The EDs and water exposure assumptions were used to derive Risk-Based Water Concentrations (CFU/100mL) for mission-critical illness severity levels over a range of water use activities common to military operations. Human dose-response studies, data and analyses indicate that ingestion exposures at the estimated ED 1 (50CFU) are unlikely to be associated with diarrheal illness while ingestion exposures at the lower limit (200CFU) of the estimated ED 10 are not expected to result in a level of diarrheal illness associated with degraded individual capability. The current analysis indicates that the estimated ED 20 (approximately 1000CFU) represents initiation of a more advanced stage of diarrheal illness associated with clinical care. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Enhancing drought resilience with conjunctive use and managed aquifer recharge in California and Arizona

NASA Astrophysics Data System (ADS)

Scanlon, Bridget R.; Reedy, Robert C.; Faunt, Claudia C.; Pool, Donald; Uhlman, Kristine

2016-03-01

Projected longer-term droughts and intense floods underscore the need to store more water to manage climate extremes. Here we show how depleted aquifers have been used to store water by substituting surface water use for groundwater pumpage (conjunctive use, CU) or recharging groundwater with surface water (managed aquifer recharge, MAR). Unique multi-decadal monitoring from thousands of wells and regional modeling datasets for the California Central Valley and central Arizona were used to assess CU and MAR. In addition to natural reservoir capacity related to deep water tables, historical groundwater depletion further expanded aquifer storage by ˜44 km3 in the Central Valley and by ˜100 km3 in Arizona, similar to or exceeding current surface reservoir capacity by up to three times. Local river water and imported surface water, transported through 100s of km of canals, is substituted for groundwater (≤15 km3 yr-1, CU) or is used to recharge groundwater (MAR, ≤1.5 km3 yr-1) during wet years shifting to mostly groundwater pumpage during droughts. In the Central Valley, CU and MAR locally reversed historically declining water-level trends, which contrasts with simulated net regional groundwater depletion. In Arizona, CU and MAR also reversed historically declining groundwater level trends in active management areas. These rising trends contrast with current declining trends in irrigated areas that lack access to surface water to support CU or MAR. Use of depleted aquifers as reservoirs could expand with winter flood irrigation or capturing flood discharges to the Pacific (0-1.6 km3 yr-1, 2000-2014) with additional infrastructure in California. Because flexibility and expanded portfolio options translate to resilience, CU and MAR enhance drought resilience through multi-year storage, complementing shorter term surface reservoir storage, and facilitating water markets.

Risk-based water resources planning: Incorporating probabilistic nonstationary climate uncertainties

NASA Astrophysics Data System (ADS)

Borgomeo, Edoardo; Hall, Jim W.; Fung, Fai; Watts, Glenn; Colquhoun, Keith; Lambert, Chris

2014-08-01

We present a risk-based approach for incorporating nonstationary probabilistic climate projections into long-term water resources planning. The proposed methodology uses nonstationary synthetic time series of future climates obtained via a stochastic weather generator based on the UK Climate Projections (UKCP09) to construct a probability distribution of the frequency of water shortages in the future. The UKCP09 projections extend well beyond the range of current hydrological variability, providing the basis for testing the robustness of water resources management plans to future climate-related uncertainties. The nonstationary nature of the projections combined with the stochastic simulation approach allows for extensive sampling of climatic variability conditioned on climate model outputs. The probability of exceeding planned frequencies of water shortages of varying severity (defined as Levels of Service for the water supply utility company) is used as a risk metric for water resources planning. Different sources of uncertainty, including demand-side uncertainties, are considered simultaneously and their impact on the risk metric is evaluated. Supply-side and demand-side management strategies can be compared based on how cost-effective they are at reducing risks to acceptable levels. A case study based on a water supply system in London (UK) is presented to illustrate the methodology. Results indicate an increase in the probability of exceeding the planned Levels of Service across the planning horizon. Under a 1% per annum population growth scenario, the probability of exceeding the planned Levels of Service is as high as 0.5 by 2040. The case study also illustrates how a combination of supply and demand management options may be required to reduce the risk of water shortages.

Estimating Water Supply Arsenic Levels in the New England Bladder Cancer Study

PubMed Central

Freeman, Laura E. Beane; Lubin, Jay H.; Airola, Matthew S.; Baris, Dalsu; Ayotte, Joseph D.; Taylor, Anne; Paulu, Chris; Karagas, Margaret R.; Colt, Joanne; Ward, Mary H.; Huang, An-Tsun; Bress, William; Cherala, Sai; Silverman, Debra T.; Cantor, Kenneth P.

2011-01-01

Background: Ingestion of inorganic arsenic in drinking water is recognized as a cause of bladder cancer when levels are relatively high (≥ 150 µg/L). The epidemiologic evidence is less clear at the low-to-moderate concentrations typically observed in the United States. Accurate retrospective exposure assessment over a long time period is a major challenge in conducting epidemiologic studies of environmental factors and diseases with long latency, such as cancer. Objective: We estimated arsenic concentrations in the water supplies of 2,611 participants in a population-based case–control study in northern New England. Methods: Estimates covered the lifetimes of most study participants and were based on a combination of arsenic measurements at the homes of the participants and statistical modeling of arsenic concentrations in the water supply of both past and current homes. We assigned a residential water supply arsenic concentration for 165,138 (95%) of the total 173,361 lifetime exposure years (EYs) and a workplace water supply arsenic level for 85,195 EYs (86% of reported occupational years). Results: Three methods accounted for 93% of the residential estimates of arsenic concentration: direct measurement of water samples (27%; median, 0.3 µg/L; range, 0.1–11.5), statistical models of water utility measurement data (49%; median, 0.4 µg/L; range, 0.3–3.3), and statistical models of arsenic concentrations in wells using aquifers in New England (17%; median, 1.6 µg/L; range, 0.6–22.4). Conclusions: We used a different validation procedure for each of the three methods, and found our estimated levels to be comparable with available measured concentrations. This methodology allowed us to calculate potential drinking water exposure over long periods. PMID:21421449

G-REALM: A lake/reservoir monitoring tool for drought monitoring and water resources management.

NASA Astrophysics Data System (ADS)

Birkett, C. M.; Ricko, M.; Beckley, B. D.; Yang, X.; Tetrault, R. L.

2017-12-01

G-REALM is a NASA/USDA funded operational program offering water-level products for lakes and reservoirs and these are currently derived from the NASA/CNES Topex/Jason series of satellite radar altimeters. The main stakeholder is the USDA/Foreign Agricultural Service (FAS) though many other end-users utilize the products for a variety of interdisciplinary science and operational programs. The FAS utilize the products within their CropExplorer Decision Support System (DSS) to help assess irrigation potential, and to monitor both short-term (agricultural) and longer-term (hydrological) drought conditions. There is increasing demand for a more global monitoring service that in particular, captures the variations in the smallest (1 to 100km2) reservoirs and water holdings in arid and semi-arid regions. Here, water resources are critical to both agriculture and regional security. A recent G-REALM 10-day resolution product upgrade and expansion has allowed for more accurate lake level products to be released and for a greater number of water bodies to be monitored. The next program phase focuses on the exploration of the enhanced radar altimeter data sets from the Cryosat-2 and Sentinel-3 missions with their improved spatial resolution, and the expansion of the system to the monitoring of 1,000 water bodies across the globe. In addition, a new element, the monitoring of surface water levels in wetland zones, is also being introduced. This aims to satisfy research and stakeholder requirements with respect to programs examining the links between inland fisheries catch potential and declining water levels, and to those monitoring the delicate balance between water resources, agriculture, and fisheries management in arid basins.

Estimating water supply arsenic levels in the New England bladder cancer study

USGS Publications Warehouse

Nuckols, J.R.; Beane, Freeman L.E.; Lubin, J.H.; Airola, M.S.; Baris, D.; Ayotte, J.D.; Taylor, A.; Paulu, C.; Karagas, M.R.; Colt, J.; Ward, M.H.; Huang, A.-T.; Bress, W.; Cherala, S.; Silverman, D.T.; Cantor, K.P.

2011-01-01

Background: Ingestion of inorganic arsenic in drinking water is recognized as a cause of bladder cancer when levels are relatively high (??? 150 ??g/L). The epidemiologic evidence is less clear at the low-to-moderate concentrations typically observed in the United States. Accurate retrospective exposure assessment over a long time period is a major challenge in conducting epidemiologic studies of environmental factors and diseases with long latency, such as cancer. Objective: We estimated arsenic concentrations in the water supplies of 2,611 participants in a population-based case-control study in northern New England. Methods: Estimates covered the lifetimes of most study participants and were based on a combination of arsenic measurements at the homes of the participants and statistical modeling of arsenic concentrations in the water supply of both past and current homes. We assigned a residential water supply arsenic concentration for 165,138 (95%) of the total 173,361 lifetime exposure years (EYs) and a workplace water supply arsenic level for 85,195 EYs (86% of reported occupational years). Results: Three methods accounted for 93% of the residential estimates of arsenic concentration: direct measurement of water samples (27%; median, 0.3 ??g/L; range, 0.1-11.5), statistical models of water utility measurement data (49%; median, 0.4 ??g/L; range, 0.3-3.3), and statistical models of arsenic concentrations in wells using aquifers in New England (17%; median, 1.6 ??g/L; range, 0.6-22.4). Conclusions: We used a different validation procedure for each of the three methods, and found our estimated levels to be comparable with available measured concentrations. This methodology allowed us to calculate potential drinking water exposure over long periods.

Puget Sound Dissolved Oxygen Modeling Study: Development of an Intermediate Scale Water Quality Model

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

Khangaonkar, Tarang; Sackmann, Brandon S.; Long, Wen

2012-10-01

The Salish Sea, including Puget Sound, is a large estuarine system bounded by over seven thousand miles of complex shorelines, consists of several subbasins and many large inlets with distinct properties of their own. Pacific Ocean water enters Puget Sound through the Strait of Juan de Fuca at depth over the Admiralty Inlet sill. Ocean water mixed with freshwater discharges from runoff, rivers, and wastewater outfalls exits Puget Sound through the brackish surface outflow layer. Nutrient pollution is considered one of the largest threats to Puget Sound. There is considerable interest in understanding the effect of nutrient loads on themore » water quality and ecological health of Puget Sound in particular and the Salish Sea as a whole. The Washington State Department of Ecology (Ecology) contracted with Pacific Northwest National Laboratory (PNNL) to develop a coupled hydrodynamic and water quality model. The water quality model simulates algae growth, dissolved oxygen, (DO) and nutrient dynamics in Puget Sound to inform potential Puget Sound-wide nutrient management strategies. Specifically, the project is expected to help determine 1) if current and potential future nitrogen loadings from point and non-point sources are significantly impairing water quality at a large scale and 2) what level of nutrient reductions are necessary to reduce or control human impacts to DO levels in the sensitive areas. The project did not include any additional data collection but instead relied on currently available information. This report describes model development effort conducted during the period 2009 to 2012 under a U.S. Environmental Protection Agency (EPA) cooperative agreement with PNNL, Ecology, and the University of Washington awarded under the National Estuary Program« less

Agricultural irrigated land-use inventory for Osceola County, Florida, October 2013-April 2014

USGS Publications Warehouse

Marella, Richard L.; Dixon, Joann F.

2014-01-01

A detailed inventory of irrigated crop acreage is not available at the level of resolution needed to increase the accuracy of current water-use estimates or to project future water demands in many Florida counties. This report provides a detailed digital map and summary of irrigated areas within Osceola County for the agricultural growing period October 2013–April 2014. The irrigated areas were first delineated using land-use data and satellite imagery and then field verified between February and April 2014. Selected attribute data were collected for the irrigated areas, including crop type, primary water source, and type of irrigation system. Results indicate that an estimated 27,450 acres were irrigated during the study period. This includes 4,370 acres of vegetables, 10,970 acres of orchard crops, 1,620 acres of field crops, and 10,490 acres of ornamentals and grasses. Specifically, irrigated acreage included citrus (10,860 acres), sod (5,640 acres), pasture (4,580 acres), and potatoes (3,320 acres). Overall, groundwater was used to irrigate 18,350 acres (67 percent of the total acreage), and surface water was used to irrigate the remaining 9,100 acres (33 percent). Microirrigation systems accounted for 45 percent of the total acreage irrigated, flood systems 30 percent, and sprinkler systems the remaining 25 percent. An accurate, detailed, spatially referenced, and field-verified inventory of irrigated crop acreage can be used to assist resource managers making current and future county-level water-use estimates in Osceola County.

The Estrogenic Content of Rodent Diets, Bedding, Cages, and Water Bottles and Its Effect on Bisphenol A Studies

PubMed Central

Thigpen, Julius E; Setchell, Kenneth DR; Kissling, Grace E; Locklear, Jacqueline; Caviness, Gordon F; Whiteside, Tanya; Belcher, Scott M; Brown, Nadine M; Collins, Bradley J; Lih, Fred B; Tomer, Kenneth B; Padilla-Banks, Elizabeth; Camacho, Luísa; Adsit, Floyd G; Grant, Mary

2013-01-01

The lowest observed adverse effect level for bisphenol A (BPA) in mice and rats is currently poorly defined due to inconsistent study designs and results in published studies. The objectives of the current study were to (1) compare the estrogenic content of rodent diets, bedding, cages, and water bottles to evaluate their impact on the estrogenic activity of BPA and (2) review the literature on BPA to determine the most frequently reported diets, beddings, cages, and water bottles used in animal studies. Our literature review indicated that low-dose BPA animal studies have inconsistent results and that factors contributing to this inconsistency are the uses of high-phytoestrogen diets and the different routes of exposure. In 44% (76 of 172) of all reports, rodents were exposed to BPA via the subcutaneous route. Our literature review further indicated that the type of diet, bedding, caging, and water bottles used in BPA studies were not always reported. Only 37% (64 of 172) of the reports described the diet used. In light of these findings, we recommend the use of a diet containing low levels of phytoestrogen (less than 20 µg/g diet) and metabolizable energy (approximately 3.1 kcal/g diet) and estrogen-free bedding, cages, and water bottles for studies evaluating the estrogenic activity of endocrine-disrupting compounds such as BPA. The oral route of BPA exposure should be used when results are to be extrapolated to humans. PMID:23562095

Unconventional oil and gas development and its stresses on water resources in the context of Water-Energy-Food Nexus: The case of Weld County, Colorado

NASA Astrophysics Data System (ADS)

Oikonomou, P. D.; Waskom, R.; Boone, K.; Ryan, J. N.

2015-12-01

The development of unconventional oil and gas resources in Colorado started to rapidly increase since the early 2000's. The recent oil price plunge resulted in a decline of well starts' rate in the US, but in Weld County, Colorado, it is currently at the 2013-levels. The additional water demand, despite its insignificant percentage in overall state's demand (0.1% in 2012), it competes with traditional ones, since Colorado's water is almost fully appropriated. Presently, the state has 53,597 active producing oil and gas wells. More than 40% of these are located in Weld County, which happens also to be one of top food production U.S. counties. The competition for land and water resources between the energy and agricultural sectors in water stressed areas, like the western U.S., is further intensified if recycle and reuse practices are not preferred to water disposal by the energy industry. Satisfying the multiple objectives of the Water-Energy-Food Nexus in order to achieve sustainable economic development requires balanced management of these resources. Identifying pressures on key areas that food and energy sectors are competing for water, is essential for prudent water management and developing appropriate policies. Weld County, as a water stressed and fossil fuel producing area, was selected for investigating current stresses on local water resources alongside with future climatic and water demand scenarios for exploring probable long-term effects.

Classroom Activities about Water and Climate Change

NASA Astrophysics Data System (ADS)

Rodriguez, M.

2012-04-01

The purpose of this activity is to demonstrate practical work and experiments in the classroom, with students on Water: Water is the most neccesary Earth's resource, although it is decreasing because many human activities are changing its quality and its availability. The activity is designed in order to recreate experiments, simulations, and determine the aspects of the problematic environment currently plaguing our planet, especially those related to water and climate change. The selected activities have to be easy to make, and easy to understand. Each activity will be illustrated, explained and described using pictures and short texts, so teachers could replay them in their classroom. 1. Simulation of the Ocean Water Currents Convection to understand the heat distribution in our planet. 2. Ocean Water Stratification According to Water Salinity. We can understand the behaviour of water when we mix water from different densities 3. Melting of the Arctic and Antarctic Polar Caps. In this experiment, we can see the consequences of changing environment and climate conditions as it pertains to ice and our polar ice caps. We want to show the different behaviours of continental and floating ice and to evaluate the consequences of their melting. 4. Detecting water pollution. Here, we can analyse some water patterns and get to know the existence or absence of pollutants in the water, as well as learning how to determine its pH level, hardness, nitrogen composition, bacteria content and more. 5. Creating a home treatment. We show the necessity to preserve the water quality through a suitable treatment.

Bacteria in atmospheric waters: Detection, characteristics and implications

NASA Astrophysics Data System (ADS)

Hu, Wei; Niu, Hongya; Murata, Kotaro; Wu, Zhijun; Hu, Min; Kojima, Tomoko; Zhang, Daizhou

2018-04-01

In this review paper, we synthesize the current knowledges about bacteria in atmospheric waters, e.g., cloud, fog, rain, and snow, most of which were obtained very recently. First, we briefly describe the importance of bacteria in atmospheric waters, i.e., the essentiality of studying bacteria in atmospheric waters in understanding aerosol-cloud-precipitation-climate interactions in the Earth system. Next, approaches to collect atmospheric water samples for the detection of bacteria and methods to identify the bacteria are summarized and compared. Then the available data on the abundance, viability and community composition of bacteria in atmospheric waters are summarized. The average bacterial concentration in cloud water was usually on the order 104-105 cells mL-1, while that in precipitation on the order 103-104 cells mL-1. Most of the bacteria were viable or metabolically active. Their community composition was highly diverse and differed at various sites. Factors potentially influencing the bacteria, e.g., air pollution levels and sources, meteorological conditions, seasonal effect, and physicochemical properties of atmospheric waters, are described. After that, the implications of bacteria present in atmospheric waters, including their effect on nucleation in clouds, atmospheric chemistry, ecosystems and public health, are briefly discussed. Finally, based on the current knowledges on bacteria in atmospheric waters, which in fact remains largely unknown, we give perspectives that should be paid attention to in future studies.

Ground-water resources of Tinian, Commonwealth of the Northern Mariana Islands

USGS Publications Warehouse

Gingerich, Stephen B.; Yeatts, Daniel S.

2000-01-01

Tinian, which lies in the western Pacific Ocean at latitude 15°N and longitude 145°W (fig. 1), is the second largest island (39.2 mi2) in the Commonwealth of the Northern Mariana Islands (CNMI). Fresh ground water is obtained from shallow wells that tap the surface of a freshwater lends found in an aquifer composed mainly of coralline limestone. The main water-supply well withdraws water with a chloride concentration ranging from 160 to 220 mg/L. Current (1999) pumping rates adequately supply the island residents but future demand are expected to be higher.. To better understand the ground-water resources of the island and to learn more about the hydrology of oceanic islands, the U.S. Geological Survey (USGS) entered into a cooperative study with the Municipality of Tinian. The objective of the study, conducted between 1990 and 1997, was to assess the ground-water resources of the is;land. This report presents some of the results of the study including a description of the island's geology and geography, the current land use, the water-production system, the thickness and arcal extent of the freshwater lens, the water-table configuration and directions of ground-water flow. The report also discusses the relation of the changes in water-table elevation to daily and seasonal changes in ocean level.

Cavitation induced Becquerel effect.

PubMed

Prevenslik, T V

2003-06-01

The observation of an electrical current upon the ultraviolet (UV) illumination of one of a pair of identical electrodes in liquid water, called the Becquerel effect, was made over 150 years ago. More recently, an electrical current was found if the water surrounding one electrode was made to cavitate by focused acoustic radiation, the phenomenon called the cavitation induced Becquerel effect. Since cavitation is known to produce UV light, the electrode may simply absorb the UV light and produce the current by the photo-emission theory of photoelectrochemistry. But the current was found to be semi-logarithmic with the standard electrode potential which is characteristic of the oxidation of the electrode surface in the photo-decomposition theory, and not the photo-emission theory. High bubble collapse temperatures may oxidize the electrode, but this is unlikely because melting was not observed on the electrode surfaces. At ambient temperature, oxidation may proceed by chemical reaction provided a source of vacuum ultraviolet (VUV) radiation is available to produce the excited OH* states of water to react with the electrode. The source of VUV radiation is shown to be the spontaneous emission of coherent infrared (IR) radiation from water molecules in particles that form in bubbles because of surface tension, the spontaneous IR emission induced by cavity quantum electrodynamics. The excited OH* states are produced as the IR radiation accumulates to VUV levels in the bubble wall molecules.

NEW DISINFECTION BY-PRODUCT ISSUES: EMERGING DBP'S AND ALTERNATIVE ROUTES OF EXPOSURE

EPA Science Inventory

This paper discusses current issues with drinking water disinfection by-products (DBPs), which include emerging (unregulated) DBPs that can be formed at greater levels with alternative disinfectants (as compared to chlorine) and routes of human exposure (which include inhalation ...

Estimation of water surface elevations for the Everglades, Florida

USGS Publications Warehouse

Palaseanu, Monica; Pearlstine, Leonard

2008-01-01

The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level monitoring gages and modeling methods that provides scientists and managers with current (2000–present) online water surface and water depth information for the freshwater domain of the Greater Everglades. This integrated system presents data on a 400-m square grid to assist in (1) large-scale field operations; (2) integration of hydrologic and ecologic responses; (3) supporting biological and ecological assessment of the implementation of the Comprehensive Everglades Restoration Plan (CERP); and (4) assessing trophic-level responses to hydrodynamic changes in the Everglades.This paper investigates the radial basis function multiquadric method of interpolation to obtain a continuous freshwater surface across the entire Everglades using radio-transmitted data from a network of water-level gages managed by the US Geological Survey (USGS), the South Florida Water Management District (SFWMD), and the Everglades National Park (ENP). Since the hydrological connection is interrupted by canals and levees across the study area, boundary conditions were simulated by linearly interpolating along those features and integrating the results together with the data from marsh stations to obtain a continuous water surface through multiquadric interpolation. The absolute cross-validation errors greater than 5 cm correlate well with the local outliers and the minimum distance between the closest stations within 2000-m radius, but seem to be independent of vegetation or season.

Potential influence of sugarcane cultivation on estuarine water quality of Louisiana's gulf coast.

PubMed

Southwick, Lloyd M; Grigg, Brandon C; Kornecki, Ted S; Fouss, James L

2002-07-17

Sugarcane is cultivated on some 170000 ha of land in south central and southwestern Louisiana. This acreage drains into bayous and rivers that empty into Louisiana's coastal bays and estuaries. For a number of years the state's Department of Agriculture and Forestry and Department of Environmental Quality have collected water quality data from this sugarcane area. Study of these data shows that approximately one in five detections of atrazine is above the maximum contaminant level (MCL) for drinking water. Currently there is no U.S. atrazine standard for protection of aquatic life. February and October detections of this herbicide are probably due to sugarcane cultivation. Nitrate levels have remained below the MCL for drinking water, but nitrate and phosphorus concentrations may pose a potential for eutrophication problems. The contribution of sugarcane production to the nutrient status of Louisiana's coastal water bodies is difficult to assess because there are other sources of nutrients in the area and native soil phosphorus levels are high. Cultural practices such as subsurface drains, open drainage ditches, and postharvest residue management have potential through enhancement of soil infiltration for decreasing sugarcane's contribution to water quality problems in southern and coastal Louisiana. A new field project is being installed at the Louisiana State University Agricultural Experiment Station's Sugarcane Research Station at St. Gabriel to assess the water quality benefits of these practices with respect to sugarcane cultivation.

Atmospheric signature of the Agulhas current

NASA Astrophysics Data System (ADS)

Stela Nkwinkwa Njouodo, Arielle; Koseki, Shunya; Rouault, Mathieu; Keenlyside, Noel

2017-04-01

Satellite observation and Climate Forecast System Reanalysis (CFSR) are used to map the influence of the Agulhas current on local annual precipitation in Southern Africa. The pressure adjustment mechanism is applied over the Agulhas current region. Results unfold that the narrow band of precipitation above the Agulhas Current is collocated with surface wind convergence, sea surface temperature (SST) Laplacian and sea level pressure (SLP) Laplacian. Relationship between SLP Laplacian and wind convergence is found, with 0.54 correlation coefficient statistically significant. In the free troposphere, the band of precipitation above the Agulhas current is collocated with the wind divergence and the upward motion of wind velocity. The warm waters from the Agulhas current can influence local precipitation.

Visions for a Pan-European digital data infrastructure for groundwater quantity and quality data relevant for implementation of the Water Framework Directive.

NASA Astrophysics Data System (ADS)

Hinsby, Klaus; Broers, Hans Peter

2014-05-01

The EU Water Framework and Groundwater Directives stipulate that EU member states (MS) should ensure good groundwater chemical and quantitative by 2015. For the assessment of good chemical status the MS have to establish Natural Background Levels (NBLs) and Threshold Values (TVs) for groundwater bodies at risk and compare current concentration levels to these. In addition the MS shall ensure trend reversals in cases where contaminants or water levels show critical increasing or decreasing trends. The EU MS have to demonstrate that the quantitative and chemical status of its groundwater bodies does not put drinking water, ecosystems or other legitimate uses at risk. Easy on-line access to relevant visualizations of groundwater quality and quantity data of e.g. nitrate, chloride, arsenic and water tables in Europe's major aquifer types compiled from national databases would be of great importance for managers, authorities and scientists conducting risk and status assessments. The Water Resources Expert Group of the EuroGeoSurveys propose to develop Pan-European interactive on-line digital maps and visualizations of concentrations levels and trends, as well as calculated natural background levels and threshold values for the most important aquifer types of Europe mainly derived based on principles established in the former EU project "BRIDGE" - Background cRiteria for the IDentification of Groundwater Thresholds. Further, we propose to develop Pan-European digital and dynamic maps and cross sections in close collaboration with ecologists, which delineate dependent or associated terrestrial and aquatic ecosystems across Europe where groundwater quantity and quality plays a significant role in sustaining good ecological status of the ecosystem, and where the water resources and ecosystems are most vulnerable to climate change. Finally, integrated water resources management requires integrated consideration of both deep and shallow groundwater and surface water issues and interaction. It is therefore proposed to map regions of Europe that use coupled groundwater-surface water models in integrated water resources and river basin management. In the presentation we will show selected examples of data visualizations of importance to integrated water resources and river basin management and the implementation of the Water Framework Directive.

The Exploration Water Recovery System

NASA Technical Reports Server (NTRS)

ORourke, Mary Jane E.; Carter, Layne; Holder, Donald W.; Tomes, Kristin M.

2006-01-01

The Exploration Water Recovery System is designed towards fulfillment of NASA s Vision for Space Exploration, which will require elevation of existing technologies to higher levels of optimization. This new system, designed for application to the Exploration infrastructure, presents a novel combination of proven air and water purification technologies. The integration of unit operations is modified from that of the current state-of-the-art water recovery system so as to optimize treatment of the various waste water streams, contaminant loads, and flow rates. Optimization is achieved primarily through the removal of volatile organic contaminants from the vapor phase prior to their absorption into the liquid phase. In the current state-of-the-art system, the water vapor in the cabin atmosphere is condensed, and the volatile organic contaminants present in that atmosphere are absorbed into the aqueous phase. Removal of contaminants the5 occurs via catalytic oxidation in the liquid phase. Oxidation kinetics, however, dictate that removal of volatile organic contaminants from the vapor phase can inherently be more efficient than their removal from the aqueous phase. Taking advantage of this efficiency reduces the complexity of the water recovery system. This reduction in system complexity is accompanied by reductions in the weight, volume, power, and resupply requirements of the system. Vapor compression distillation technology is used to treat the urine, condensate, and hygiene waste streams. This contributes to the reduction in resupply, as incorporation of vapor compression distillation technology at this point in the process reduces reliance on the expendable ion exchange and adsorption media used in the current state-of-the-art water recovery system. Other proven technologies that are incorporated into the Exploration Water Recovery System include the Trace Contaminant Control System and the Volatile Removal Assembly.

Plant water potential improves prediction of empirical stomatal models.

PubMed

Anderegg, William R L; Wolf, Adam; Arango-Velez, Adriana; Choat, Brendan; Chmura, Daniel J; Jansen, Steven; Kolb, Thomas; Li, Shan; Meinzer, Frederick; Pita, Pilar; Resco de Dios, Víctor; Sperry, John S; Wolfe, Brett T; Pacala, Stephen

2017-01-01

Climate change is expected to lead to increases in drought frequency and severity, with deleterious effects on many ecosystems. Stomatal responses to changing environmental conditions form the backbone of all ecosystem models, but are based on empirical relationships and are not well-tested during drought conditions. Here, we use a dataset of 34 woody plant species spanning global forest biomes to examine the effect of leaf water potential on stomatal conductance and test the predictive accuracy of three major stomatal models and a recently proposed model. We find that current leaf-level empirical models have consistent biases of over-prediction of stomatal conductance during dry conditions, particularly at low soil water potentials. Furthermore, the recently proposed stomatal conductance model yields increases in predictive capability compared to current models, and with particular improvement during drought conditions. Our results reveal that including stomatal sensitivity to declining water potential and consequent impairment of plant water transport will improve predictions during drought conditions and show that many biomes contain a diversity of plant stomatal strategies that range from risky to conservative stomatal regulation during water stress. Such improvements in stomatal simulation are greatly needed to help unravel and predict the response of ecosystems to future climate extremes.

Building new WDM regulations for the Namibian tourism sector on factors influencing current water-management practices at the enterprise level

NASA Astrophysics Data System (ADS)

Schachtschneider, Klaudia

Namibia's aridity is forcing its water sector to resort to new water resource management approaches, including water demand management (WDM). Such a change in management approach is facilitated through the country's opportunity at independence to rewrite and adapt its old policies, including those for water and tourism. Legal support for WDM through the Water Act and other sector-specific Acts is crucial to plan the practical implementation of WDM throughout the different water use sectors of Namibia. In order to be able to put the policy into practice, it is imperative to understand which factors motivate people to adopt WDM initiatives. Within the Namibian tourism industry three main factors have been identified which influence the water-management approaches at tourist facilities. This paper discusses how the water and tourism decision makers can consider these factors when developing new regulations to introduce WDM in the tourism sector.

Water Supply at Los Alamos 1998-2001

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

Richard J. Koch; David B. Rogers

2003-03-01

For the period 1998 through 2001, the total water used at Los Alamos from all sources ranged from 1325 million gallons (Mg) in 1999 to 1515 Mg in 2000. Groundwater production ranged from 1323 Mg in 1999 to 1506 Mg in 2000 from the Guaje, Pajarito, and Otowi fields. Nonpotable surface water used from Los Alamos reservoir ranged from zero gallons in 2001 to 9.3 Mg in 2000. For years 1998 through 2001, over 99% of all water used at Los Alamos was groundwater. Water use by Los Alamos National Laboratory (LANL) between 1998 and 2001 ranged from 379 Mgmore » in 2000 to 461 Mg in 1998. The LANL water use in 2001 was 393 Mg or 27% of the total water use at Los Alamos. Water use by Los Alamos County ranged from 872 Mg in 1999 to 1137 Mg in 2000, and averaged 1006 Mg/yr. Four new replacement wells in the Guaje field (G-2A, G-3A, G-4A, and G-5A) were drilled in 1998 and began production in 1999; with existing well G-1A, the Guaje field currently has five producing wells. Five of the old Guaje wells (G-1, G-2, G-4, G-5, and G-6) were plugged and abandoned in 1999, and one well (G-3) was abandoned but remains as an observation well for the Guaje field. The long-term water level observations in production and observation (test) wells at Los Alamos are consistent with the formation of a cone of depression in response to water production. The water level decline is gradual and at most has been about 0.7 to 2 ft per year for production wells and from 0.4 to 0.9 ft/yr for observation (test) wells. The largest water level declines have been in the Guaje field where nonpumping water levels were about 91 ft lower in 2001 than in 1951. The initial water levels of the Guaje replacement wells were 32 to 57 ft lower than the initial water levels of adjacent original Guaje wells. When production wells are taken off-line for pump replacement or repair, water levels have returned to within about 25 ft of initial static levels within 6 to 12 months. Thus, the water-level trends suggest no adverse impacts by production on long-term water supply sustainability at Los Alamos. This report summarizes production data and aquifer conditions for water production and monitor wells in the Los Alamos, New Mexico, and Los Alamos National Laboratory (LANL) area (Figure 1). Water production wells are grouped within the Guaje, Pajarito, and Otowi fields, the locations of which are shown on Figure 1. Wells from these fields supply all the potable water used for municipal and most industrial purposes in Los Alamos County (LAC), at LANL, and at Bandelier National Monument. This report has three primary objectives: (1) Provide a continuing historical record of metered well production and overall water usage; (2) Provide data to the Department of Energy (DOE) and LANL management, and Los Alamos County planners for operation of the water supply system and for long-range water resource planning; and (3) Provide water-level data from regional aquifer production wells, test wells, and monitoring wells.« less

Ground-Water Availability in the Wailuku Area, Maui, Hawai'i

USGS Publications Warehouse

Gingerich, Stephen B.

2008-01-01

Most of the public water supply in Maui, Hawai'i, is from a freshwater lens in the Wailuku area of the island. Because of population growth, ground-water withdrawals from wells in this area increased from less than 10 Mgal/d during 1970 to about 23 Mgal/d during 2006. In response to increased withdrawals from the freshwater lens in the Wailuku area, water levels declined, the transition zone between freshwater and saltwater became shallower, and the chloride concentrations of water pumped from wells increased. These responses led to concern over the long-term sustainability of withdrawals from existing and proposed wells. A three-dimensional numerical ground-water flow and transport model was developed to simulate the effects of selected withdrawal and recharge scenarios on water levels, on the transition zone between freshwater and saltwater, and on surface-water/ground-water interactions. The model was constructed using time-varying recharge, withdrawals, and ocean levels. Hydraulic characteristics used to construct the model were initially based on published estimates but ultimately were varied to obtain better agreement between simulated and measured water levels and salinity profiles in the modeled area during the period 1926-2006. Scenarios included ground-water withdrawal at 2006 and 1996 rates and locations with average recharge (based on 2000-04 land use and 1926-2004 rainfall) and withdrawal at redistributed rates and locations with several different recharge scenarios. Simulation results indicate that continuing 1996 and 2006 withdrawal distributions into the future results in decreased water levels, a thinner freshwater lens, increased salinity from pumped wells, and higher salinity at several current withdrawal sites. A redistributed withdrawal condition in which ground-water withdrawal was redistributed to maximize withdrawal and minimize salinities in the withdrawn water was determined. The redistributed withdrawal simulates 27.1 Mgal/d of withdrawal from 14 wells or well fields in the Wailuku area. Simulation results from the five scenarios that include redistributed withdrawal conditions indicate the following for the Wailuku Aquifer Sector: (1) withdrawal during times of average recharge rates cause average water levels to decrease 2-3 ft and the transition zone to become more than 200 ft shallower after 150 years; (2) a 5-yr drought condition similar to the 1998-2002 drought results in additional salinity increases after 30 years (12.5 years of normal recharge after drought conditions) but only one well has salinity increases of concern; (3) additional recharge from restored streamflow significantly increases water levels, thickens the freshwater body, and decreases salinity at withdrawal sites in the Waihe'e and 'Iao Aquifer Systems; and (4) a complete removal of irrigation recharge decreases water levels and increases salinity in the central isthmus where irrigation is reduced, but recharge through restored streams still significantly increases water levels, thickens the freshwater body, and decreases salinity at withdrawal sites in the Waihe'e and 'Iao Aquifer Systems.

Plan for assessment of the occurrence, status, and distribution of volatile organic compounds in aquifers of the United States

USGS Publications Warehouse

Lapham, W.W.; Tadayon, Saeid

1996-01-01

The occurrence of volatile organic compounds (VOCs) in water is of national concern because of their relatively high aqueous solubility, mobility, and persistence, because many are known or suspected carcinogens, because of their widespread use, and because they have been found in drinking-water supplies. Because of this national concern, VOCs were selected for National investigation (hereafter termed "National Synthesis") by the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program in 1994. The broad goals of this National Synthesis are to: (1) describe current water- quality conditions with respect to VOCs; (2) define trends, or lack of trends, in VOCs in surface and ground water; and (3) identify, describe, and explain causal relations among the occurrence and distribution of VOCs in surface water and ground water, and natural and human factors. The National Synthesis of VOCs in ground water has three objectives: (1) to describe their occurrence, status, and distribution; (2) to determine relations among VOCs in shallow ground water and natural and human factors; and (3) to determine, compare, and contrast the occurrence, transformation, transport, and fate of selected VOCs in the hydrologic cycle for several regionally or nationally important aquifer systems. The description of VOC occurrence, status, and distribution in ground water focuses on major aquifers of the United States. Occurrence describes the presence or absence of VOCs, their frequency of occurrence, and their ranges of concentrations. Status compares the concentrations of VOCs detected in relation to water-quality regulations or advisories, such as Maximum Contaminant Levels, Proposed Maximum Contaminant Levels, Maximum Contaminant Level Goals, and Health Advisories. Distribution describes the variability of VOCs in ground water, areally and by depth. This report describes the study design for conducting such an assessment. The assessment focuses on aquifers, or parts of aquifers, that are currently used or have the potential to be used as sources of water supplies, using data collected as part of local, State, and Federal ground-water monitoring programs since 1985. Assessment by aquifer and comparison of results among aquifers will be completed for those aquifers for which adequate spatial or depth-related data are available. Assessment of VOCs in aquifers also will be completed at regional and national scales. A set of criteria for well-network design, well construction, sample-collection methods, and methods of laboratory analysis must be met before VOC data are used for assessment. An appropriate well-network design will provide a generally unbiased, random, equal-area distribution of sampling sites throughout the aquifer, or part of the aquifer, of interest. Well-construction information must be sufficient to ensure that the hydrogeologic unit (or units) represented by the water level measured and the hydrologic unit (or units) contributing water to the well are known. In addition, the well construction and pumping equipment in the well need to be of a type that are not likely to affect concentrations of VOCs in the water sample. VOC data will be considered suitable for use in the occurrence assessment if nationally accepted methods for collection and analysis were used and if the quantitation level for VOC analytes was less than about 5 micrograms per liter; laboratory analysis was done by a laboratory certified by the U.S. Environ- mental Protection Agency; and the sample was collected from untreated (raw) water at or near the well head before being held in a pressure tank or holding tank.

Coastal circulation and water-column properties in the War in the Pacific National Historical Park, Guam: measurements and modeling of waves, currents, temperature, salinity, and turbidity, April-August 2012

USGS Publications Warehouse

Storlazzi, Curt D.; Cheriton, Olivia M.; Lescinski, Jamie M.R.; Logan, Joshua B.

2014-01-01

The U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center (PCMSC) initiated an investigation in the National Park Service’s (NPS) War in the Pacific National Historical Park (WAPA) to provide baseline scientific information on coastal circulation and water-column properties along west-central Guam, focusing on WAPA’s Agat Unit, as it relates to the transport and settlement of coral larvae, fish, and other marine organisms. The oceanographic data and numerical circulation modeling results from this study demonstrate that circulation in Agat Bay was strongly driven by winds and waves at longer (>1 day) timescales and by the tides at shorter (<1 day) timescales; near-surface currents in deep water were primarily controlled by the winds, whereas currents on the shallow reef flats were dominated by wave-driven motions. Water-column properties exhibited strong seasonality coupled to the shift from the trade wind to the non-trade wind season. During the dry trade-wind season, waters were cooler and more saline. When the winds shifted to a more variable pattern, waters warmed and became less saline because of a combination of increased thermal insolation from lack of wind forcing and higher rainfall. Turbidity was relatively low in Agat Bay and was similar to levels measured elsewhere along west-central Guam. The numerical circulation modeling results provide insight into the potential paths of buoyant material released from a series of locations along west-central Guam under summer non-trade wind forcing conditions that characterize coral spawning events. This information may be useful in evaluating the potential zones of influence/impact resulting from transport by surface currents of material released from these select locations.

Circulation and water properties in the landfast ice zone of the Alaskan Beaufort Sea

NASA Astrophysics Data System (ADS)

Weingartner, Thomas J.; Danielson, Seth L.; Potter, Rachel A.; Trefry, John H.; Mahoney, Andy; Savoie, Mark; Irvine, Cayman; Sousa, Leandra

2017-09-01

Moorings, hydrography, satellite-tracked drifters, and high-frequency radar data describe the annual cycle in circulation and water properties in the landfast ice zone (LIZ) of the Alaskan Beaufort Sea. Three seasons, whose duration and characteristics are controlled by landfast ice formation and ablation, define the LIZ: ;winter;, ;break-up;, and ;open-water;. Winter begins in October with ice formation and ends in June when rivers commence discharging. Winter LIZ ice velocities are zero, under-ice currents are weak ( 5 cm s-1), and poorly correlated with winds and local sea level. The along-shore momentum balance is between along-shore pressure gradients and bottom and ice-ocean friction. Currents at the landfast ice-edge are swift ( 35 cm s-1), wind-driven, with large horizontal shears, and potentially unstable. Weak cross-shore velocities ( 1 cm s-1) imply limited exchanges between the LIZ and the outer shelf in winter. The month-long break-up season (June) begins with the spring freshet and concludes when landfast ice detaches from the bottom. Cross-shore currents increase, and the LIZ hosts shallow ( 2 m), strongly-stratified, buoyant and sediment-laden, under-ice river plumes that overlie a sharp, 1 m thick, pycnocline across which salinity increases by 30. The plume salt balance is between entrainment and cross-shore advection. Break-up is followed by the 3-month long open-water season when currents are swift (≥20 cm s-1) and predominantly wind-driven. Winter water properties are initialized by fall advection and evolve slowly due to salt rejection from ice. Fall waters and ice within the LIZ derive from local rivers, the Mackenzie and/or Chukchi shelves, and the Arctic basin.

USGS ground-water flow model : an essential tool for managing the water supply of the Virginia Coastal Plain

USGS Publications Warehouse

Erwin, Martha L.; McFarland, Randolph E.; Scott, Bruce T.

1999-01-01

Virginia needs a reliable water supply to sustain its growing population and expanding economy. In 1990, the aquifers in the Coastal Plain supplied about 100 million gallons per day (mgd) to the citizens, businesses, and industries of Virginia. It is estimated that by the year 2000, demand will increase by another 10 mgd and likely will continue to increase in future years.Ground water is the only source of usable water in rural areas of the Coastal Plain and increasingly is being used to support a growing urban population. Current withdrawals have led to declining water levels in most Coastal Plain aquifers. Further declines are likely to occur, posing a threat that saltwater will move into parts of these freshwater aquifers.

A population-based case-control study of drinking-water nitrate and congenital anomalies using Geographic Information Systems (GIS) to develop individual-level exposure estimates.

PubMed

Holtby, Caitlin E; Guernsey, Judith R; Allen, Alexander C; Vanleeuwen, John A; Allen, Victoria M; Gordon, Robert J

2014-02-05

Animal studies and epidemiological evidence suggest an association between prenatal exposure to drinking water with elevated nitrate (NO3-N) concentrations and incidence of congenital anomalies. This study used Geographic Information Systems (GIS) to derive individual-level prenatal drinking-water nitrate exposure estimates from measured nitrate concentrations from 140 temporally monitored private wells and 6 municipal water supplies. Cases of major congenital anomalies in Kings County, Nova Scotia, Canada, between 1988 and 2006 were selected from province-wide population-based perinatal surveillance databases and matched to controls from the same databases. Unconditional multivariable logistic regression was performed to test for an association between drinking-water nitrate exposure and congenital anomalies after adjusting for clinically relevant risk factors. Employing all nitrate data there was a trend toward increased risk of congenital anomalies for increased nitrate exposure levels though this was not statistically significant. After stratification of the data by conception before or after folic acid supplementation, an increased risk of congenital anomalies for nitrate exposure of 1.5-5.56 mg/L (2.44; 1.05-5.66) and a trend toward increased risk for >5.56 mg/L (2.25; 0.92-5.52) was found. Though the study is likely underpowered, these results suggest that drinking-water nitrate exposure may contribute to increased risk of congenital anomalies at levels below the current Canadian maximum allowable concentration.

A Population-Based Case-Control Study of Drinking-Water Nitrate and Congenital Anomalies Using Geographic Information Systems (GIS) to Develop Individual-Level Exposure Estimates

PubMed Central

Holtby, Caitlin E.; Guernsey, Judith R.; Allen, Alexander C.; VanLeeuwen, John A.; Allen, Victoria M.; Gordon, Robert J.

2014-01-01

Animal studies and epidemiological evidence suggest an association between prenatal exposure to drinking water with elevated nitrate (NO3-N) concentrations and incidence of congenital anomalies. This study used Geographic Information Systems (GIS) to derive individual-level prenatal drinking-water nitrate exposure estimates from measured nitrate concentrations from 140 temporally monitored private wells and 6 municipal water supplies. Cases of major congenital anomalies in Kings County, Nova Scotia, Canada, between 1988 and 2006 were selected from province-wide population-based perinatal surveillance databases and matched to controls from the same databases. Unconditional multivariable logistic regression was performed to test for an association between drinking-water nitrate exposure and congenital anomalies after adjusting for clinically relevant risk factors. Employing all nitrate data there was a trend toward increased risk of congenital anomalies for increased nitrate exposure levels though this was not statistically significant. After stratification of the data by conception before or after folic acid supplementation, an increased risk of congenital anomalies for nitrate exposure of 1.5–5.56 mg/L (2.44; 1.05–5.66) and a trend toward increased risk for >5.56 mg/L (2.25; 0.92–5.52) was found. Though the study is likely underpowered, these results suggest that drinking-water nitrate exposure may contribute to increased risk of congenital anomalies at levels below the current Canadian maximum allowable concentration. PMID:24503976

The direct determination of dose-to-water using a water calorimeter.

PubMed

Schulz, R J; Wuu, C S; Weinhous, M S

1987-01-01

A flexible, temperature-regulated, water calorimeter has been constructed which consists of three nested cylinders. The innermost "core" is a 10 X 10 cm right cylinder made of glass, the contents of which are isolated from the environment. It has two Teflon-washered glass valves for filling, and two thermistors are supported at the center by glass capillary tubes. Surrounding the core is a "jacket" that provides approximately 2 cm of air insulation between the core and the "shield." The shield surrounds the jacket with a 2.5-cm layer of temperature-regulated water flowing at 51/min. The core is filled with highly purified water the gas content of which is established prior to filling. Convection currents, which may be induced by dose gradients or thermistor power dissipation, are eliminated by operating the calorimeter at 4 degrees C. Depending upon the power level of the thermistors, 15-200 microW, and the insulation provided by the glass capillary tubing, the temperature of the thermistors is higher than that of the surrounding water. To minimize potential errors caused by differences between calibration curves obtained at finite power levels, the zero-power-level calibration curve obtained by extrapolation is employed. Also the calorimeter response is corrected for the change in power level, and therefore thermistor temperature, that follows the resistance change caused by irradiation. The response of the calorimeter to 4-MV x rays has been compared to that of an ionization chamber irradiated in an identical geometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Late quaternary history and uranium isotopic compositions of ground water discharge deposits, Crater Flat, Nevada

USGS Publications Warehouse

Paces, James B.; Taylor, Emily M.; Bush, Charles

1993-01-01

Three carbonate-rich spring deposits are present near the southern end of Crater Flat, NV, approximately 18 km southwest of the potential high-level waste repository at Yucca Mountain. We have analyzed five samples of carbonate-rich material from two of the deposits for U and Th isotopic compositions. Resulting U-series disequilibrium ages indicate that springs were active at 18 ?? 1, 30 ?? 3, 45 ?? 4 and >70 ka. These ages are consistent with a crude internal stratigraphy at one site. Identical ages for two samples at two separate sites suggest that springs were contemporaneous, at least in part, and were most likely part of the same hydrodynamic system. In addition, initial U isotopic compositions range from 2.8 to 3.8 and strongly suggest that ground water from the regional Tertiary-volcanic aquifer provided the source for these hydrogenic deposits. This interpretation, along with water level data from near-by wells suggest that the water table rose approximately 80 to 115 m above present levels during the late Quaternary and may have fluctuated repeatedly. Current data are insufficient to allow reconstruction of a detailed depositional history, however geochronological data are in good agreement with other paleoclimatic proxy records preserved throughout the region. Since these deposits are down gradient from the potential repository site, the possibility of higher ground water levels in the future dramatically shortens both vertical and lateral ground water pathways and reduces travel times of transported radionuclides to potential discharge sites.

Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin, With Special Emphasis on Responses of an Oligotrophic Seepage Lake to Changes in Phosphorus Loading and Water Level

USGS Publications Warehouse

Robertson, Dale M.; Rose, William J.; Juckem, Paul F.

2009-01-01

Whitefish Lake, which is officially named Bardon Lake, is an oligotrophic, soft-water seepage lake in northwestern Wisconsin, and classified by the Wisconsin Department of Natural Resources as an Outstanding Resource Water. Ongoing monitoring of the lake demonstrated that its water quality began to degrade (increased phosphorus and chlorophyll a concentrations) around 2002 following a period of high water level. To provide a better understanding of what caused the degradation in water quality, and provide information to better understand the lake and protect it from future degradation, the U.S. Geological Survey did a detailed study from 2004 to 2008. The goals of the study were to describe the past and present water quality of the lake, quantify water and phosphorus budgets for the lake, simulate the potential effects of changes in phosphorus inputs on the lake's water quality, analyze changes in the water level in the lake since 1900, and relate the importance of changes in climate and changes in anthropogenic (human-induced) factors in the watershed to the water quality of the lake. Since 1998, total phosphorus concentrations increased from near the 0.005-milligrams per liter (mg/L) detection limit to about 0.010 mg/L in 2006, and then decreased slightly in 2007-08. During this time, chlorophyll a concentrations and Secchi depths remained relatively stable at about 1.5 micrograms per liter (ug/L) and 26 feet, respectively. Whitefish Lake is typically classified as oligotrophic. Because the productivity in Whitefish Lake is limited by phosphorus, phosphorus budgets were constructed for the lake. Because it was believed that much of its phosphorus comes from the atmosphere, phosphorus deposition was measured in this study. Phosphorus input from the atmosphere was greater than computed based on previously reported wetfall phosphorus concentrations. The concentrations and deposition rates can be used to estimate atmospheric loading in future lake studies. The average annual load of phosphorus to the lake was 232 pounds: 56 percent from precipitation, 27 percent from groundwater, and 16 percent from septic systems. During a series of dry years (low water levels) and wet years (high water levels), the inputs of water and phosphorus ranged by only 10-13 percent. Results from the Canfield and Bachmann eutrophication model and Carlson trophic-state-index equations demonstrated that the lake directly responds to changes in external phosphorus loading, with percent change in chlorophyll a being similar to the percent change in loading and the change in total phosphorus and Secchi depth being slightly smaller. Therefore, changes in phosphorus loading should affect the water quality of the lake. Specific scenarios that simulated the effects of anthropogenic (human-induced) and climatic (water level) changes demonstrated that: surface-water inflow (runoff) based on current development has little effect on pelagic water quality, changes in the inputs from septic systems and development in the watershed could have a large effect on water quality, and decreases in water and phosphorus loading during periods of low water level had little effect on water quality. Sustained high water levels, resulting from several wet years with relatively high water and phosphorus input, however, could cause a small degradation in water quality. Although high water levels may be associated with a degradation in water quality, it appears that anthropogenic changes in the watershed may be more important in affecting the future water quality of the lake. Fluctuations in water levels since 1998 are representative of what has occurred since 1900, with fluctuations of about 3 feet occurring about every 15 years. Based on total phosphorus concentrations inferred from sediment core analysis, there has been little long-term change in water quality and there has been a slight deterioration in water quality following most periods of high water levels. There

Flood-inundation maps for the Wabash River at Memorial Bridge at Vincennes, Indiana

USGS Publications Warehouse

Fowler, Kathleen K.; Menke, Chad D.

2017-08-23

Digital flood-inundation maps for a 10.2-mile reach of the Wabash River from Sevenmile Island to 3.7 mile downstream of Memorial Bridge (officially known as Lincoln Memorial Bridge) at Vincennes, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at USGS streamgage 03343010, Wabash River at Memorial Bridge at Vincennes, Ind. Near-real-time stages at this streamgage may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service at http:/water.weather.gov/ahps/, which also forecasts flood hydrographs at this site.For this study, flood profiles were computed for the Wabash River reach by means of a one-dimensional stepbackwater model. The hydraulic model was calibrated by using the most current stage-discharge relations at USGS streamgage 03343010, Wabash River at Memorial Bridge at Vincennes, Ind., and preliminary high-water marks from a high-water event on April 27, 2013. The calibrated hydraulic model was then used to determine 19 water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from 10 feet (ft) or near bankfull to 28 ft, the highest stage of the current stage-discharge rating curve. The simulated water-surface profiles were then combined with a Geographic Information System (GIS) digital elevation model (DEM, derived from Light Detection and Ranging [lidar] data having a 0.98-ft vertical accuracy and 4.9-ft horizontal resolution) in order to delineate the area flooded at each water level.The availability of these maps—along with Internet information regarding current stage from the USGS streamgage 03343010, and forecast stream stages from the NWS AHPS—provides emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

Water quality prediction of marine recreational beaches receiving watershed baseflow and stormwater runoff in southern California, USA.

PubMed

He, Li-Ming Lee; He, Zhen-Li

2008-05-01

Beach advisories are issued to the public in California when the concentration of fecal indicator bacteria (FIB), including total coliform, fecal coliform (or Escherichia coli), and Enterococcus, exceed their recreational water health standards, or when the amount of a rainfall event is above the pre-determined threshold. However, it is not fully understood about how and to what degree stormwater runoff or baseflow exerts impacts on beach water quality. Furthermore, current laboratory methods used to determine the FIB levels take 18-96 h, which is too slow to keep pace with changes in FIB levels in water. Thus, a beach may not be posted when it is contaminated, and may be posted under advisory when bacterial levels have already decreased to within water quality standards. The study was designed to address the above critical issues. There were large temporal and spatial variations in FIB concentrations along two popular State Beaches in San Diego, CA, USA. The rainstorm-induced runoff from the watersheds exerts significant impacts on the marine recreational water quality of the beaches adjacent to lagoons during the first 24-48 h after a rain event. The large volume of stormwater runoff discharging to beaches caused high FIB concentrations in beach water not only at the lagoon outlet channel and the mixing zone, but also at the locations 90 m away from the channel northward or southward along the shoreline. The geomorphology of beach shoreline, distance from the outlet channel, wind strength, wind direction, tide height, wave height, rainfall, time lapse after a rainstorm, or channel flow rate played a role in affecting the distribution of FIB concentrations in beach water. Despite the great temporal and spatial variability of FIB concentrations along a shoreline, the artificial neural network-based models developed in this study are capable of successfully predicting FIB concentrations at different beaches, different locations, and different times under baseflow or rainstorm conditions. The models are based on readily measurable variables including temperature, conductivity, pH, turbidity, channel water flow, rainfall, and/or time lapse after a rainstorm. The established models will help fill the current gap between beach posting and actual water quality and make more meaningful and effective decisions on beach closures and advisories.

The National Shipbuilding Research Program. Analysis of Wash Water Treatment Efficiency for Copper and Zinc

DTIC Science & Technology

2000-12-15

per trillion for tributyltin (“ TBT ”). This regulatory action lead to an intensive research effort to develop a treatment method for ship’s wash water...antifoulant coating systems, including tributyltin , copper and zinc. In 1997 The Commonwealth of Virginia established an effluent discharge limit of 50 parts...waste stream that could consistently remove TBT to levels below this discharge standard. This work is currently being performed by the Center for

Shelf Circulation Induced by an Orographic Wind Jet

NASA Astrophysics Data System (ADS)

Ràfols, Laura; Grifoll, Manel; Jordà, Gabriel; Espino, Manuel; Sairouní, Abdel; Bravo, Manel

2017-10-01

The dynamical response to cross-shelf wind-jet episodes is investigated. The study area is located at the northern margin of the Ebro Shelf, in the Northwestern (NW) Mediterranean Sea, where episodes of strong northwesterly wind occur. In this case, the wind is channeled through the Ebro Valley and intensifies upon reaching the sea, resulting in a wind jet. The wind-jet response in terms of water circulation and vertical density structure is investigated using a numerical model. The numerical outputs agree with water current observations from a high-frequency radar. Additionally, temperature, sea level, and wind measurements are also used for the skill assessment of the model. For the wind-jet episodes, the numerical results show a well-defined two-layer circulation in the cross-shelf direction, with the surface currents in the direction of the wind. This pattern is consistent with sea level set-down due to the wind effect. The comparison of the vertical structure response for different episodes revealed that the increase of stratification leads to an onshore displacement of the transition from inner shelf to mid-shelf. In general, the cross-shelf momentum balance during a wind-jet episode exhibits a balance between the frictional terms and the pressure gradient in shallow waters, shifting to a balance between the Coriolis force and the wind stress terms in deeper waters.

An evaluation of the readability of drinking water quality reports: a national assessment.

PubMed

Roy, Siddhartha; Phetxumphou, Katherine; Dietrich, Andrea M; Estabrooks, Paul A; You, Wen; Davy, Brenda M

2015-09-01

The United States Environmental Protection Agency mandates that community water systems (or water utilities) provide annual consumer confidence reports (CCRs)--water quality reports--to their consumers. These reports encapsulate information regarding sources of water, detected contaminants, regulatory compliance, and educational material. These reports have excellent potential for providing the public with accurate information on the safety of tap water, but there is a lack of research on the degree to which the information can be understood by a large proportion of the population. This study evaluated the readability of a nationally representative sample of 30 CCRs, released between 2011 and 2013. Readability (or 'comprehension difficulty') was evaluated using Flesch-Kincaid readability tests. The analysis revealed that CCRs were written at the 11th-14th grade level, which is well above the recommended 6th-7th grade level for public health communications. The CCR readability ease was found to be equivalent to that of the Harvard Law Review journal. These findings expose a wide chasm that exists between current water quality reports and their effectiveness toward being understandable to US residents. Suggestions for reorienting language and scientific information in CCRs to be easily comprehensible to the public are offered.

[Field study on the change of urinary iodine levels among family members with iodine content of 5 - 150 microg/L in drinking water before and after non-iodized salt intervention].

PubMed

Li, Su-mei; Zhang, Gen-hong; Sun, Fan; Wang, Pei-hua; Zhang, Zhi-zhong; Li, Xiu-wei; Li, Shu-hua

2008-08-01

To compare the changes of urinary iodine levels among the family members with iodine content of 5 - 150 microg/L in drinking water, before and after non-iodized salt intervention through a field trail study. Family members who routinely drank water with iodine content 5 - 150 microg/L were chosen to substitute non-iodized salt for their current iodized salt for 2 months, and urine samples of the family members were collected for determination of iodine change before and after intervention was carried out. Median urinary iodine of school children, women with productive age and male adults exceeding 370 microg/L before intervention and the frequency distribution of urinary iodine were all above 70%. Our results revealed that iodine excess exited in three groups of family members. After intervention, all median urinary iodine level seemed to have decreased significantly, and groups with drinking water iodine 5.0 - 99.9 microg/L reduced to adequate or close to adequate while the group that drinking water iodine was 100 - 150 microg/L reached the cut-off point of excessive iodine level (300 microg/L). Results from your study posed the idea that the iodine adequate areas should be defined as the areas with iodine content of 5.0 - 100 microg/L in drinking water, and edible salt not be iodized in these areas. Areas with iodine content of 100 - 150 microg/L in drinking water should be classified as iodine excessive.

Evaluating the impact of municipal water fluoridation on the aquatic environment.

PubMed Central

Osterman, J W

1990-01-01

Although highly beneficial for dental health, low concentrations of fluoride in environmental waters may be toxic to several organisms. In an era of heightened public awareness about the environment, this may lead city officials to withhold implementing water fluoridation for environmental reasons. This paper presents a mass balance approach to evaluate this perceived risk. Generally speaking, fluoridated water loss during use, dilution of sewage by rain and ground water infiltrate, fluoride removal during secondary sewage treatment, and diffusion dynamics at effluent outfall combine to eliminate fluoridation-related environmental effects. In Montreal, water fluoridation would raise average aquatic fluoride levels in the waste water plume immediately below effluent outfall by only 0.05-0.09 mg/l. Downstream, these changes would be only 0.02-0.05 mg/l at 1 km, and 0.01-0.03 mg/l at 2 km below outfall. Overall river fluoride concentrations theoretically would be raised by 0.001-0.002 mg/l, a value not measurable by current analytical techniques. All resulting concentrations would be well below those recommended for environmental safety and would not exceed natural levels found elsewhere in Quebec. A literature review did not reveal any examples of municipal water fluoridation causing recommended environmental concentrations to be exceeded, although excesses occurred in several cases of severe industrial water pollution. PMID:2400035

U.S. Geological Survey Ground-Water Climate Response Network

USGS Publications Warehouse

,

2007-01-01

The U.S. Geological Survey serves the Nation by providing reliable hydrologic information used by others to manage the Nation's water resources. The U.S. Geological Survey (USGS) measures more than 20,000 wells each year for a variety of objectives as part of Federal programs and in cooperation with State and local agencies. Water-level data are collected using consistent data-collection and quality-control methods. A small subset of these wells meets the criteria necessary to be included in a 'Climate Response Network' of wells designed to illustrate the response of the ground-water system to climate variations nationwide. The primary purpose of the Climate Response Network is to portray the effect of climate on ground-water levels in unconfined aquifers or near-surface confined aquifers that are minimally affected by pumping or other anthropogenic stresses. The Climate Response Network Web site (http://groundwaterwatch.usgs.gov/) is the official USGS Web site for illustrating current ground-water conditions in the United States and Puerto Rico. The Climate Response Network Web pages provide information on ground-water conditions at a variety of scales. A national map provides a broad overview of water-table conditions across the Nation. State maps provide a more local picture of ground-water conditions. Site pages provide the details about a specific well.

New York Harbor water quality survey, 1994. Executive summary. Final report

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

Brosnan, T.M.; O`Shea, M.L.

1995-10-24

This summary presents the results of the 1994 survey, followed by a synopsis of recent changes to pollutant loads from NYC facilities. In general, conventional water quality, as indicated by coliform bacterica and DO levels, continues to improve in most areas of NY Harbor. However, violations of the `never less than` DO standards, although improved, are still occasionally recorded at 50-75% of all stations in summer. Therefore, loadings of nutrients and organic carbon, and changes in water column stratification and flushing rate, remain a concern, as does the appropriateness of the current `never the less` DO standards.

New York Harbor water quality survey, 1994. (Includes appendices). Final report

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

Brosnan, T.M.; O`Shea, M.L.

1995-11-15

This summary presents the results of the 1994 survey, followed by a synopsis of recent changes to pollutant loads from NYC facilities. In general, conventional water quality, as indicated by coliform bacterica and DO levels, continues to improve in most areas of NY Harbor. However, violations of the `never less than` DO standards, although improved, are still occasionally recorded at 50-75% of all stations in summer. Therefore, loadings of nutrients and organic carbon, and changes in water column stratification and flushing rate, remain a concern, as does the appropriateness of the current `never the less` DO standards.

A customized resistivity system for monitoring saturation and seepage in earthen levees: installation and validation

NASA Astrophysics Data System (ADS)

Arosio, Diego; Munda, Stefano; Tresoldi, Greta; Papini, Monica; Longoni, Laura; Zanzi, Luigi

2017-10-01

This work is based on the assumption that a resistivity meter can effectively monitor water saturation in earth levees and can be used as a warning system when saturation exceeds the expected seasonal maxima. We performed time-lapse ERT measurements to assess the capability of this method to detect areas where seepage is critical. These measurements were also very useful to design a prototype monitoring system with remarkable savings by customizing the specifications according to field observations. The prototype consists of a remotely controlled low-power resistivity meter with a spread of 48 stainless steel 20 × 20 cm plate electrodes buried at half-meter depth. We deployed the newly-designed permanent monitoring system on a critical levee segment. A weather station and an ultrasonic water level sensor were also installed in order to analyse the correlation of resistivity with temperature, rainfalls and water level seasonal variations. The preliminary analysis of the monitoring data shows that the resistivity maps follow a very reasonable trend related with the saturation/drying cycle of the levee caused by the seasonal variations of the water level in the irrigation channel. Sharp water level changes cause delayed and smooth resistivity variations. Rainfalls and, to a lesser extent, temperature seem to have an influence on the collected data but effects are apparently negligible beyond 1 m depth. The system is currently operating and results are continuously monitored.

U.S. drinking water challenges in the twenty-first century.

PubMed

Levin, Ronnie B; Epstein, Paul R; Ford, Tim E; Harrington, Winston; Olson, Erik; Reichard, Eric G

2002-02-01

The access of almost all 270 million U.S. residents to reliable, safe drinking water distinguishes the United States in the twentieth century from that of the nineteenth century. The United States is a relatively water-abundant country with moderate population growth; nonetheless, current trends are sufficient to strain water resources over time, especially on a regional basis. We have examined the areas of public water infrastructure, global climate effects, waterborne disease (including emerging and resurging pathogens), land use, groundwater, surface water, and the U.S. regulatory history and its horizon. These issues are integrally interrelated and cross all levels of public and private jurisdictions. We conclude that U.S. public drinking water supplies will face challenges in these areas in the next century and that solutions to at least some of them will require institutional changes.

U.S. drinking water challenges in the twenty-first century.

PubMed Central

Levin, Ronnie B; Epstein, Paul R; Ford, Tim E; Harrington, Winston; Olson, Erik; Reichard, Eric G

2002-01-01

The access of almost all 270 million U.S. residents to reliable, safe drinking water distinguishes the United States in the twentieth century from that of the nineteenth century. The United States is a relatively water-abundant country with moderate population growth; nonetheless, current trends are sufficient to strain water resources over time, especially on a regional basis. We have examined the areas of public water infrastructure, global climate effects, waterborne disease (including emerging and resurging pathogens), land use, groundwater, surface water, and the U.S. regulatory history and its horizon. These issues are integrally interrelated and cross all levels of public and private jurisdictions. We conclude that U.S. public drinking water supplies will face challenges in these areas in the next century and that solutions to at least some of them will require institutional changes. PMID:11834462

Marine nitrous oxide emissions: An unknown liability for the international water sector

EPA Science Inventory

Reliable estimates of anthropogenic greenhouse gas (GHG) emissions are essential for setting effective climate policy at both the sector and national level. Current IPCC Guidelines for calculating nitrous oxide (N2O) emissions from sewage management are both highly uncertain and ...

CONSIDERATION IN THE DESIGN OF TREATMENT BEST MANAGEMENT PRACTICES (BMPS) TO IMPROVE WATER QUALITY

EPA Science Inventory

For the past three decades, municipalities in the United States have successfully addressed pollution in the watershed by collecting and treating their wastewater. Currently, all municipalities provide secondary level treatment, and in some cases tertiary treatment, and industri...

An insight into the drinking-water access in the health institutions at the Saharawi refugee camps in Tindouf (Algeria) after 40years of conflict.

PubMed

Vivar, M; Pichel, N; Fuentes, M; Martínez, F

2016-04-15

Drinking water access in the Saharawi refugee camps located in the Algerian desert is a challenge that is still an on-going problem after 40years of conflict. This work presents an analysis of the situation with emphasis on the water supply in health institutions (quantity and quality) including both sanitary inspections and a comprehensive water quality study. Results from sanitary inspections show that only half of the water supply installations at the hospitals are in adequate conditions and the rest present high risk of microbiological contamination. Water access in small medical community centres on the other hand present issues related to the non-availability of food-grade water tanks for the institutions (70%), the use of small 10l containers as the main water supply (40%), poor maintenance (60% under antihygienic conditions and 30% with damaged covers), and insufficient chlorine levels that prevent microbiological contamination. Regarding water quality analyses, raw water supply in Smara, El Aiun and Awserd camps present high conductivity and high levels of fluoride, chloride, nitrate and sulphate, but dropping to normal levels within the drinking-water standards after water treatment via reverse osmosis plants. But for the case of El Aiun and Awserd, the reverse osmosis plant only provides treated water to the population each 20days, so the population receives raw water directly and health risks should be evaluated. Finally, Dakhla water supply is the best in terms of physico-chemical parameters quality, currently providing safe drinking water after a chlorination stage. In summary, drinking water access has improved dramatically in the last years due to the efforts of local and international authorities but several issues remain to be solved: access to treated water for all the population, improved water quality controls (especially in Dakhla), expansion of distribution networks, and adequate storage systems and maintenance. Copyright © 2016 Elsevier B.V. All rights reserved.

Pre-anthropocene mercury residues in North American freshwater fish.

PubMed

Hope, Bruce K; Louch, Jeff

2014-04-01

Mercury (Hg) has been entering the environment from both natural and anthropogenic sources for millennia, and humans have been influencing its environmental transport and fate from well before the Industrial Revolution. Exposure to Hg (as neurotoxic monomethylmercury [MeHg]) occurs primarily through consumption of finfish, shellfish, and marine mammals, and regulatory limits for MeHg concentrations in fish tissue have steadily decreased as information on its health impacts has become available. These facts prompted us to consider 2 questions: 1) What might the MeHg levels in fish tissue have been in the pre-Anthropocene, before significant human impacts on the environment? and 2) How would these pre-Anthropocene levels have compared with current regulatory criteria for MeHg residues in fish tissue? We addressed the first question by estimating pre-Anthropocene concentrations of MeHg in the tissues of prey and predatory fish with an integrated Hg speciation, transport, fate, and food web model (SERAFM), using estimated Hg concentrations in soil, sediment, and atmospheric deposition before the onset of significant human activity (i.e., ≤2000 BCE). Model results show MeHg residues in fish varying depending on the characteristics of the modeled water body, which suggests that Hg in fish tissue is best considered at the scale of individual watersheds or water bodies. We addressed the second question by comparing these model estimates with current regulatory criteria and found that MeHg residues in predatory (but not prey) fish could have approached or exceeded these criteria in some water bodies during the pre-Anthropocene. This suggests that the possibility of naturally occurring levels of Hg in fish below which it is not possible to descend, regardless of where those levels stand with respect to current regulatory limits. Risk management decisions made under these circumstances have the potential to be ineffectual, frustrating, and costly for decision makers and stakeholders alike, suggesting the need for regulatory flexibility when addressing the issue of Hg in fish. © 2013 SETAC.

Appraisal of ground water in the vicinity of the Leadville drainage tunnel, Lake County, Colorado

USGS Publications Warehouse

Turk, John T.; Taylor, O. James

1979-01-01

Ground water in the Leadville mining district occurs in granite, quartzite, limestone, sandstone, porphyry dikes, and unconsolidated material. These rocks form a single aquifer system because the formations are hydraulically connected through contact, mine workings, faulting, and fracturing. The aquifer is recharged by precipitation and water moves toward California Gulch and probably toward Evans Gulch, in the drainage basin of the Arkansas River. The Leadville drainage tunnel was constructed from 1943 to 1945 and later extended during 1950 to 1952, in order to drain the mine workings. Discharge from the tunnel lowered water levels 30 to 96 feet in mine shafts from 1944 to 1951. Installation of an impervious plug in the tunnel has been proposed in order to reduce the discharge of water containing objectionable concentrations of trace metals into the East Fork Arkansas River. The proposed plug would reduce the discharge from the tunnel, cause water levels east of the town of Leadville to rise, flood some mine workings, and increase ground-water discharge to California Gulch. However, the proposed plug is not expected to cause water levels in Leadville to rise substantially, but more current and detailed data are needed to verify this. Discharge from the Leadville drainage tunnel is probably a mixture of water in equilibrium with carbonate aquifer materials from the mineralized zone, water acidified by the localized oxidation of pyrite from the mineralized zone, and water nearly saturated with calcite from the glacial mantle. Based on limited data, water from the carbonate mineral deposits has a pH of about 7.0 and concentrations of manganese of about 1,800 micrograms per liter and zinc concentrations of about 13,000 micrograms per liter. (USGS)

Water stress mitigates the negative effects of ozone on photosynthesis and biomass in poplar plants.

PubMed

Gao, Feng; Catalayud, Vicent; Paoletti, Elena; Hoshika, Yasutomo; Feng, Zhaozhong

2017-11-01

Tropospheric ozone (O 3 ) pollution frequently overlaps with drought episodes but the combined effects are not yet understood. We investigated the physiological and biomass responses of an O 3 sensitive hybrid poplar clone ('546') under three O 3 levels (charcoal-filtered ambient air, non-filtered ambient air (NF), and NF plus 40 ppb) and two watering regimes (well-watered (WW) and reduced watering (RW), i.e. 40% irrigation) for one growing season. Water stress increased chlorophyll and carotenoid contents, protecting leaves from pigment degradation by O 3 . Impairment of photosynthesis by O 3 was also reduced by stomatal closure due to water stress, which preserved light-saturated CO 2 assimilation rate, and the maximum carboxylation efficiency. Water stress increased water use efficiency of the leaves while O 3 decreased it, showing significant interactions. Effects were more evident in older leaves than in younger leaves. Water stress reduced biomass production, but the negative effects of O 3 were less in RW than in WW for total biomass per plant. A stomatal O 3 flux-based dose-response relationship was parameterized considering water stress effects, which explained biomass losses much better than a concentration-based approach. The O 3 critical level of Phytotoxic Ozone Dose over a threshold of 7 nmol O 3 .m -2 .s -1 (POD 7 ) for a 4% biomass loss in this poplar clone under different water regimes was 4.1 mmol m -2 . Our results suggest that current O 3 levels in most parts of China threaten poplar growth and that interaction with water availability is a key factor for O 3 risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

The study of Lake Urmia desiccation: morphometry impress

NASA Astrophysics Data System (ADS)

Moradi, Ayoub; Rasouli, Ali Akbar; Roostaei, Shahram

2017-04-01

Located in northwestern Iran, the hypersaline Lake Urmia has started a serious uninterrupted desiccation since 1995. The lake has lost about eight meters of water level and about 75% of water surface area during past 20 years. In particular, the lake water volume decrement has been accelerated in recent years. The importance of the Lake Urmia for human life in northwestern Iran, and its destructive effects on a vast region if totally dry up, demands comprehensive studies of the lake level fluctuations mechanism. According to literature review, the water volume of the lake behaves sometimes differently from the water storage of the whole basin. Our time series analysis using Land Data Assimilation Systems also confirms those differences within last decades. In other hand, many studies addressed the lake desiccation to climatic changes and/or anthropogenic influences such as excessive dam constructions in the watershed during last decades. As water leaves the lake only through evaporation, the fluctuation of evaporation has a distinctive role in the lake level variations. Dramatic decreament in the lake extent indicates of a special morphometry. The lake's morphometry has made it vulnerable to temperature and salinity changes. It strongly controls the lake's water heat capacity and water density. And, it therefore controls the rate of evaporation from water surface. We study the role of lake's morphometry on the lake desiccation. Although, the global climatic change is known as the primary reason for current droughts in the Middle East generally, our preliminary results show that the lake's morphometry is the main cause for the accelerating of water volume lost in Lake Urmia. In particular, after 2007, lake's water temperature and density show significant variations. Water heat capacity and evaporation rate are consistent with information of lake's hypsometry.

Organic compounds in produced waters from coalbed natural gas wells in the Powder River Basin, Wyoming, USA

USGS Publications Warehouse

Orem, W.H.; Tatu, C.A.; Lerch, H.E.; Rice, C.A.; Bartos, T.T.; Bates, A.L.; Tewalt, S.; Corum, M.D.

2007-01-01

The organic composition of produced water samples from coalbed natural gas (CBNG) wells in the Powder River Basin, WY, sampled in 2001 and 2002 are reported as part of a larger study of the potential health and environmental effects of organic compounds derived from coal. The quality of CBNG produced waters is a potential environmental concern and disposal problem for CBNG producers, and no previous studies of organic compounds in CBNG produced water have been published. Organic compounds identified in the produced water samples included: phenols, biphenyls, N-, O-, and S-containing heterocyclic compounds, polycyclic aromatic hydrocarbons (PAHs), aromatic amines, various non-aromatic compounds, and phthalates. Many of the identified organic compounds (phenols, heterocyclic compounds, PAHs) are probably coal-derived. PAHs represented the group of organic compounds most commonly observed. Concentrations of total PAHs ranged up to 23 ??g/L. Concentrations of individual compounds ranged from about 18 to <0.01 ??g/L. Temporal variability of organic compound concentrations was documented, as two wells with relatively high organic compound contents in produced water in 2001 had much lower concentrations in 2002. In many areas, including the PRB, coal strata provide aquifers for drinking water wells. Organic compounds observed in produced water are also likely present in drinking water supplied from wells in the coal. Some of the organic compounds identified in the produced water samples are potentially toxic, but at the levels measured in these samples are unlikely to have acute health effects. The human health effects of low-level, chronic exposure to coal-derived organic compounds in drinking water are currently unknown. Continuing studies will evaluate possible toxic effects from low level, chronic exposure to coal-derived organic compounds in drinking water supplies.

The influence of sea-level rise on fringing reef sediment dynamics: field observations and numerical modeling

USGS Publications Warehouse

Storlazzi, Curt D.; Field, Michael E.; Elias, Edwin; Presto, M. Katherine

2011-01-01

While most climate projections suggest that sea level may rise on the order of 0.5-1.0 m by 2100, it is not clear how fluid flow and sediment transport on fringing reefs might change in response to this rapid sea-level rise. Field observations and numerical modeling suggest that an increase in water depth on the order of 0.5-1.0 m on a fringing reef flat would result in larger significant wave heights and wave-driven shear stresses, which, in turn, would result in an increase in both the size and quantity of sediment that can be resuspended from the seabed or eroded from coastal plain deposits. Greater wave- and wind-driven currents would develop on the reef flat with increasing water depth, increasing the offshore flux of water and sediment from the inner reef flat to the outer reef flat and fore reef where coral growth is typically greatest.

Water and Forest Health: Drought Stress as a Core Driver of Forest Disturbances and Tree Mortality in Western North America

NASA Astrophysics Data System (ADS)

Allen, C. D.; Williams, P.

2012-12-01

Increasing warmth and dry climate conditions have affected large portions of western North America in recent years, causing elevated levels of both chronic and acute forest drought stress. In turn, increases in drought stress amplify the incidence and severity of the most significant forest disturbances in this region, including wildfire, drought-induced tree mortality, and outbreaks of damaging insects and diseases. Regional patterns of drought stress and various forest disturbances are reviewed, including interactions among climate and the various disturbance processes; similar global-scale patterns and trends of drought-amplified forest die-off and high-severity wildfire also are addressed. New research is presented that derives a tree-ring-based Forest Drought Stress Index (FDSI) for the three most widespread conifer species (Pinus edulis, Pinus ponderosa, and Pseudotsuga menziesii) in the southwestern US (Arizona, New Mexico), demonstrating nonlinear escalation of FDSI to levels unprecedented in the past 1000 years, in response to both drought and especially recent warming. This new work further highlights strong correlations between drought stress and amplified forest disturbances (fire, bark beetle outbreaks), and projects that by ca. 2050 anticipated regional warming will cause mean FDSI levels to reach extreme levels that may exceed thresholds for the survival of current tree species in large portions of their current range. Given recent trends of forest disturbance and projections for substantially warmer temperatures and greater drought stress for much of western North America in coming years, the growing risks to western forest health are becoming clear. This emerging understanding suggests an urgent need to determine potentials and methods for managing water on-site to maintain the vigor and resilience of western forests in the face of increasing levels of climate-induced water stress.

The Effect of Drought on Stomatal Conductance in the Biosphere 2 Rainforest

NASA Astrophysics Data System (ADS)

Gay, J. D.; Van Haren, J. L. M.

2015-12-01

Drought is a major climate change concern for the Earth's rainforests; however little is currently known about how these forests and individual plants will respond to water stress. At the individual level, the ability of plants to regulate their stomatal conductance is an important preservation mechanism that helps to cool leaves, regulate water loss, and uptake carbon dioxide. At the ecosystem level, transpiration in rainforests is a major contributor to the positive feedback loop that returns moisture to the atmosphere for continued precipitation cycles. Nearly 60% of atmospheric moisture in the Amazon rain forests has been traced back to origins of transpiration from its plants. In relation to current climatic conditions, stomatal conductance rates are highly variable across rainforest species and environmental conditions. It is still unknown to what extent these rates will decrease at leaf and forest level in response to periods of drought. The University of Arizona's Biosphere 2 (B2) served as the study site for a simulated 4-week long drought because of its ability to mimic the micrometeorology of an Amazonian rainforest. Three species of plants were chosen at various levels in the canopy: Clitoria racemosa, Cissus sicyoides, and Hibiscus elatus. These plants were selected based on their relative abundance and distribution in the B2 forest. It was revealed that two out of the three species exhibited decreases in H20 efflux at each elevation, while one species (C. racemosa) proved much more resistant, at each elevation, to H20 loss. These results may be useful for future integrative modeling of how individual leaf level responses extend to entire ecosystem scales. It will be important to better understand how rainforests conserve, recycle, and lose water to gauge their response to warming climate, and increased periods of drought in the tropics.

Climate and water resource change impacts and adaptation potential for US power supply

DOE PAGES

Miara, Ariel; Macknick, Jordan E.; Vorosmarty, Charles J.; ...

2017-10-30

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptationmore » strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. As a result, climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.« less

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

Fant, Charles; Schlosser, C. Adam; Gao, Xiang

The sustainability of future water resources is of paramount importance and is affected by many factors, including population, wealth and climate. Inherent in current methods to estimate these factors in the future is the uncertainty of their prediction. In this study, we integrate a large ensemble of scenarios—internally consistent across economics, emissions, climate, and population—to develop a risk portfolio of water stress over a large portion of Asia that includes China, India, and Mainland Southeast Asia in a future with unconstrained emissions. We isolate the effects of socioeconomic growth from the effects of climate change in order to identify themore » primary drivers of stress on water resources. We find that water needs related to socioeconomic changes, which are currently small, are likely to increase considerably in the future, often overshadowing the effect of climate change on levels of water stress. As a result, there is a high risk of severe water stress in densely populated watersheds by 2050, compared to recent history. There is strong evidence to suggest that, in the absence of autonomous adaptation or societal response, a much larger portion of the region’s population will live in water-stressed regions in the near future. Lastly, tools and studies such as these can effectively investigate large-scale system sensitivities and can be useful in engaging and informing decision makers.« less

Climate and water resource change impacts and adaptation potential for US power supply

NASA Astrophysics Data System (ADS)

Miara, Ariel; Macknick, Jordan E.; Vörösmarty, Charles J.; Tidwell, Vincent C.; Newmark, Robin; Fekete, Balazs

2017-11-01

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptation strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. Climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.

Droughts in Georgia

USGS Publications Warehouse

Barber, Nancy L.; Stamey, Timothy C.

2000-01-01

Droughts do not have the immediate effects of floods, but sustained droughts can cause economic stress throughout the State. The word 'drought' has various meanings, depending on a person's perspective. To a farmer, a drought is a period of moisture deficiency that affects the crops under cultivation - even two weeks without rainfall can stress many crops during certain periods of the growing cycle. To a meteorologist, a drought is a prolonged period when precipitation is less than normal. To a water manager, a drought is a deficiency in water supply that affects water availability and water quality. To a hydrologist, a drought is an extended period of decreased precipitation and streamflow. Droughts in Georgia have severely affected municipal and industrial water supplies, agriculture, stream water quality, recreation at major reservoirs, hydropower generation, navigation, and forest resources. In Georgia, droughts have been documented at U.S. Geological Survey (USGS) streamflow gaging stations since the 1890's. From 1910 to 1940, about 20 streamflow gaging stations were in operation. Since the early 1950's through the late 1980's, about 100 streamflow gaging stations were in operation. Currently (2000), the USGS streamflow gaging network consists of more than 135 continuous-recording gages. Ground-water levels are currently monitored at 165 wells equipped with continuous recorders.

Climate and water resource change impacts and adaptation potential for US power supply

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

Miara, Ariel; Macknick, Jordan E.; Vorosmarty, Charles J.

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptationmore » strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. As a result, climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.« less

Torsional ultrasonic technique for reactor vessel liquid level measurement

NASA Astrophysics Data System (ADS)

Dress, W. B.

A detailed study of an ultrasonic waveguide employed as a level, density, and temperature sensor was undertaken. The purpose was to show how such a device might be used in the nuclear power industry to provide reliable level information with a multifunction sensor, thus overcoming several of the errors that led to the accident at Three Mile Island. Some additional work is needed to answer the question raised by the current study, most noticably the damping effects of flowing water.

[Geochemical distribution of dissolved bismuth in the Yellow Sea and East China Sea].

PubMed

Wu, Xiao-Dan; Song, Jin-Ming; Wu, Bin; Li, Xue-Gang

2014-01-01

Occurrence level, geochemical distribution of dissolved bismuth and its coupling relationship to eco-environment were investigated in the Yellow Sea and East China Sea to explore the source and influencing factors. The results showed that the concentration of dissolved bismuth was within the range of 0-0. 029 microg x L(-1) at the surface and 0.001-0.189 microg x L(-1) at the bottom, with the averages of 0.008 and 0.016 microg x L(-1), respectively. Horizontally, low value of dissolved bismuth exhibited the bidirectional extension feature, indicating that it could trace the path of Changjiang Diluted Water. High value of dissolved bismuth was observed where the Subei Costal Current and Yellow Sea Warm Current flowed and the Changjiang Diluted Water and Zhejiang-Fujian Coastal Current met, suggesting that it was controlled by the cycle of current system. Vertically, the coastal water was fully mixed by water convection and eddy mixing, and was divided from the stratified water by strong tidal front, which blocked the transport of dissolved bismuth to the open sea. Thus, the concentration in front area was significantly higher than that in the open sea. Diurnal variation of dissolved bismuth was related to the hydrodynamic conditions (tide, suspension and thermocline) instead of the environmental factors (temperature and salinity). Positive relationship to SPM (suspended particulate matter) clarified that bismuth was prone to release from solid phase to liquid phase. Furthermore, conditions with temperature ranging 22-27 degrees C, salinity ranging 28-31 and pH ranging 7.9-8.1 were shown to be optimal for the release process.

Airborne Imaging in the Yukon River Basin to Characterize SWOT Mission Phenomenology

NASA Astrophysics Data System (ADS)

Moller, D.; Pavelsky, T.; Arvesen, J. C.

2015-12-01

Remote sensing offers intriguing tools to track Arctic hydrology, but current techniques are largely limited to tracking either inundation or water surface elevation only. For the first time, the proposed Surface Water Ocean Topography (SWOT) satellite mission will provide regular, simultaneous observations of inundation extent and water level from space. SWOT is unique and distinct from precursor altimetry missions in some notable regards: 1) 100km+ of swath will provide complete ocean coverage, 2) in addition to the ocean product, land surface water will be mapped for storage measurement and discharge estimation and 3) Ka-band single-pass interferometry will produce the height measurements introducing a new measurement technique. This new approach introduces additional algorithmic, characterization and calibration/validation needs for which the Ka-band SWOT Phenomenology Airborne Radar (KaSPAR) was developed. In May 2015, AirSWOT (comprised of KaSPAR and a color infrared (CIR) high resolution aerial camera) was part of an intensive field campaign including observations of inundation extent and water level and in situ hydrologic measurements in two rivers and 20 lakes within the Yukon River Basin, Alaska. One goal is to explore the fundamental phenomenology of the SWOT measurement. This includes assessment of the effects of vegetation layover and attenuation, wind roughening and classification. Further KaSPAR-derived inundation extent will to be validated using a combination of ground surveys and coregistered CIR imagery. Ultimately, by combining measurements of changing inundation extent and water level between two collection dates, it will be possible to validate lake water storage variations against storage changes computed from in situ water levels and inundation area derived from AirSWOT. Our paper summarizes the campaign, the airborne and in situ measurements and presents some initial KaSPAR and CIR imagery from the Yukon flats region.

Risk of breast cancer following exposure to tetrachloroethylene-contaminated drinking water in Cape Cod, Massachusetts: reanalysis of a case-control study using a modified exposure assessment

PubMed Central

2011-01-01

Background Tetrachloroethylene (PCE) is an important occupational chemical used in metal degreasing and drycleaning and a prevalent drinking water contaminant. Exposure often occurs with other chemicals but it occurred alone in a pattern that reduced the likelihood of confounding in a unique scenario on Cape Cod, Massachusetts. We previously found a small to moderate increased risk of breast cancer among women with the highest exposures using a simple exposure model. We have taken advantage of technical improvements in publically available software to incorporate a more sophisticated determination of water flow and direction to see if previous results were robust to more accurate exposure assessment. Methods The current analysis used PCE exposure estimates generated with the addition of water distribution modeling software (EPANET 2.0) to test model assumptions, compare exposure distributions to prior methods, and re-examine the risk of breast cancer. In addition, we applied data smoothing to examine nonlinear relationships between breast cancer and exposure. We also compared a set of measured PCE concentrations in water samples collected in 1980 to modeled estimates. Results Thirty-nine percent of individuals considered unexposed in prior epidemiological analyses were considered exposed using the current method, but mostly at low exposure levels. As a result, the exposure distribution was shifted downward resulting in a lower value for the 90th percentile, the definition of "high exposure" in prior analyses. The current analyses confirmed a modest increase in the risk of breast cancer for women with high PCE exposure levels defined by either the 90th percentile (adjusted ORs 1.0-1.5 for 0-19 year latency assumptions) or smoothing analysis cut point (adjusted ORs 1.3-2.0 for 0-15 year latency assumptions). Current exposure estimates had a higher correlation with PCE concentrations in water samples (Spearman correlation coefficient = 0.65, p < 0.0001) than estimates generated using the prior method (0.54, p < 0.0001). Conclusions The incorporation of sophisticated flow estimates in the exposure assessment method shifted the PCE exposure distribution downward, but did not meaningfully affect the exposure ranking of subjects or the strength of the association with the risk of breast cancer found in earlier analyses. Thus, the current analyses show a slightly elevated breast cancer risk for highly exposed women, with strengthened exposure assessment and minimization of misclassification by using the latest technology. PMID:21600013

Wave-driven fluxes through New River Inlet, NC

NASA Astrophysics Data System (ADS)

Wargula, A.; Raubenheimer, B.; Elgar, S.

2012-12-01

The importance of wave forcing to inlet circulation is examined using observations of waves, water levels, and currents collected in and near New River Inlet, NC during April and May, 2012. A boat-mounted system was used to measure current profiles along transects across the inlet mouth during three 14-hr periods, providing information on cross-inlet current structure, as well as discharge. Additionally, an array of 13 colocated pressure gages and profilers were deployed along 2 km of the inlet channel (5 to 10 m water depths) and ebb shoal channel (2 to 3 m water depths) and 19 colocated pressure gages and acoustic Doppler velocimeters were deployed across and offshore of the ebb shoal (1 to 5 m water depths) (Figure 1). The inlet is well mixed and tidal currents ranged from +/- 1.5 m/s, maximum discharge rates at peak ebb and flood were about 700 to 900 m3/s, offshore significant wave heights Hsig were 0.5 to 2.5 m, and wind speeds ranged from 0 to 14 m/s. Time-integrated residual discharge over semi-diurnal tidal cycles with similar ranges was ebb dominant during calm conditions (May 11, net out-of-inlet discharge ~ 55 m3, Hsig ~ 0.5 m, NW winds ~ 3 m/s) and flood dominant during stormier conditions (May 14, net into-inlet discharge ~ 15 m3, Hsig ~ 1.2 m, S winds ~ 6.5 m/s). Low-pass filtered in situ profiler data suggest wave-forcing affects the fluxes into and out of the inlet. The observations will be used to examine the momentum balance governing the temporal and cross-inlet (channel vs. shoal) variation of these fluxes, as well as the effect of waves on ebb and flood flow dominance. Funding provided by the Office of Naval Research and a National Security Science and Engineering Faculty Fellowship.; Figure 1: Google Earth image of New River Inlet, NC. Colors are depth contours (scale on the right, units are m relative to mean sea level) and symbols are locations of colocated current meters and pressure gages.

Effects of currents and tides on fine-scale use of marine bird habitats in a Southeast Alaska hotspot

USGS Publications Warehouse

Drew, Gary S.; Piatt, John F.; Hill, David J.

2013-01-01

Areas with high species richness have become focal points in the establishment of marine protected areas, but an understanding of the factors that support this diversity is still incomplete. In coastal areas, tidal currents—modulated by bathymetry and manifested in variable speeds—are a dominant physical feature of the environment. However, difficulties resolving tidally affected currents and depths at fine spatial-temporal scales have limited our ability to understand their influence the distribution of marine birds. We used a hydrographic model of the water mass in Glacier Bay, Alaska to link depths and current velocities with the locations of 15 common marine bird species observed during fine-scale boat-based surveys of the bay conducted during June of four consecutive years (2000-2003). Marine birds that forage on the bottom tended to occupy shallow habitats with slow-moving currents; mid-water foragers used habitats with intermediate depths and current speeds; and surface-foraging species tended to use habitats with fast-moving, deep waters. Within foraging groups there was variability among species in their use of habitats. While species obligated to foraging near bottom were constrained to use similar types of habitat, species in the mid-water foraging group were associated with a wider range of marine habitat characteristics. Species also showed varying levels of site use depending on tide stage. The dramatic variability in bottom topography—especially the presence of numerous sills, islands, headlands and channels—and large tidal ranges in Glacier Bay create a wide range of current-affected fine-scale foraging habitats that may contribute to the high diversity of marine bird species found there.

Sustainable water future with global implications: everyone's responsibility.

PubMed

Kuylenstierna, J L; Bjorklund, G; Najlis, P

1997-01-01

The current use and management of freshwater is not sustainable in many countries and regions of the world. If current trends are maintained, about two-thirds of the world's population will face moderate to severe water stress by 2025 compared to one-third at present. This water stress will hamper economic and social development unless action is taken to deal with the emerging problems. The Comprehensive Assessment of the Freshwater Resources of the World, prepared by the UN and the Stockholm Environment Institute, calls for immediate action to prevent further deterioration of freshwater resources. Although most problems related to water quantity and quality require national and regional solutions, only a global commitment can achieve the necessary agreement on principles, as well as financial means to attain sustainability. Due to the central and integrated role played by water in human activities, any measures taken need to incorporate a wide range of social, ecological and economic factors and needs. The Assessment thus addresses the many issues related to freshwater use, such as integrated land and water management at the watershed level, global food security, water supply and sanitation, ecosystem requirements, pollution, strengthening of major groups, and national water resource assessment capabilities and monitoring networks. Governments are urged to work towards a consensus regarding global principles and guidelines for integrated water management, and towards their implementation in local and regional water management situations. The alternative development options available to countries facing water stress, or the risk thereof, needs to be considered in all aspects of development planning.

Evidence for Legacy Contamination of Nitrate in Groundwater of North Carolina Using Monitoring and Private Well Data Models

NASA Astrophysics Data System (ADS)

Messier, K. P.; Kane, E.; Bolich, R.; Serre, M. L.

2014-12-01

Nitrate (NO3-) is a widespread contaminant of groundwater and surface water across the United States that has deleterious effects to human and ecological health. Legacy contamination, or past releases of NO3-, is thought to be impacting current groundwater and surface water of North Carolina. This study develops a model for predicting point-level groundwater NO3- at a state scale for monitoring wells and private wells of North Carolina. A land use regression (LUR) model selection procedure known as constrained forward nonlinear regression and hyperparameter optimization (CFN-RHO) is developed for determining nonlinear model explanatory variables when they are known to be correlated. Bayesian Maximum Entropy (BME) is then used to integrate the LUR model to create a LUR-BME model of spatial/temporal varying groundwater NO3- concentrations. LUR-BME results in a leave-one-out cross-validation r2 of 0.74 and 0.33 for monitoring and private wells, effectively predicting within spatial covariance ranges. The major finding regarding legacy sources NO3- in this study is that the LUR-BME models show the geographical extent of low-level contamination of deeper drinking-water aquifers is beyond that of the shallower monitoring well. Groundwater NO3- in monitoring wells is highly variable with many areas predicted above the current Environmental Protection Agency standard of 10 mg/L. Contrarily, the private well results depict widespread, low-level NO3-concentrations. This evidence supports that in addition to downward transport, there is also a significant outward transport of groundwater NO3- in the drinking water aquifer to areas outside the range of sources. Results indicate that the deeper aquifers are potentially acting as a reservoir that is not only deeper, but also covers a larger geographical area, than the reservoir formed by the shallow aquifers. Results are of interest to agencies that regulate surface water and drinking water sources impacted by the effects of legacy NO3- sources. Additionally, the results can provide guidance on factors affecting the point-level variability of groundwater NO3- and areas where monitoring is needed to reduce uncertainty. Lastly, LUR-BME predictions can be integrated into surface water models for more accurate management of non-point sources of nitrogen.

Evaluation of Handheld Assays for the Detection of Ricin and Staphylococcal Enterotoxin B in Disinfected Waters

PubMed Central

Wade, Mary Margaret; Biggs, Tracey D.; Insalaco, Joseph M.; Neuendorff, Lisa K.; Bevilacqua, Vicky L. H.; Schenning, Amanda M.; Reilly, Lisa M.; Shah, Saumil S.; Conley, Edward K.; Emanuel, Peter A.; Zulich, Alan W.

2011-01-01

Development of a rapid field test is needed capable of determining if field supplies of water are safe to drink by the warfighter during a military operation. The present study sought to assess the effectiveness of handheld assays (HHAs) in detecting ricin and Staphylococcal Enterotoxin B (SEB) in water. Performance of HHAs was evaluated in formulated tap water with and without chlorine, reverse osmosis water (RO) with chlorine, and RO with bromine. Each matrix was prepared, spiked with ricin or SEB at multiple concentrations, and then loaded onto HHAs. HHAs were allowed to develop and then read visually. Limits of detection (LOD) were determined for all HHAs in each water type. Both ricin and SEB were detected by HHAs in formulated tap water at or below the suggested health effect levels of 455 ng/mL and 4.55 ng/mL, respectively. However, in brominated or chlorinated waters, LODs for SEB increased to approximately 2,500 ng/mL. LODs for ricin increased in chlorinated water, but still remained below the suggested health effect level. In brominated water, the LOD for ricin increased to approximately 2,500 ng/mL. In conclusion, the HHAs tested were less effective at detecting ricin and SEB in disinfected water, as currently configured. PMID:21792355

Concentration and quantification of somatic and F+ coliphages from recreational waters.

PubMed

McMinn, Brian R; Huff, Emma M; Rhodes, Eric R; Korajkic, Asja

2017-11-01

Somatic and F+ coliphages are promising alternative fecal indicators, but current detection methods are hindered by lower levels of coliphages in surface waters compared to traditional bacterial fecal indicators. We evaluated the ability of dead-end hollow fiber ultrafiltration (D- HFUF) and single agar layer (SAL) procedure to concentrate and enumerate coliphages from 1L and 10L volumes of ambient surface waters (lake, river, marine), river water with varying turbidities (3.74-118.7 NTU), and a simulated combined sewer overflow (CSO) event. Percentage recoveries for surface waters were 40-79% (somatic) and 35-94% (F+). The method performed equally well in all three matrices at 1L volumes, but percent recoveries were significantly higher in marine waters at 10L volumes when compared to freshwater. Percent recoveries at 1L and 10L were similar, except in river water where recoveries were significantly lower at higher volume. In highly turbid waters, D-HFUF-SAL had a recovery range of 25-77% (somatic) and 21-80% (F+). The method produced detectable levels of coliphages in diluted wastewater and in unspiked surface waters, emphasizing its applicability to CSO events and highlighting its utility in recovery of low coliphage densities from surface waters. Thus D-HFUF-SAL is a good candidate method for routine water quality monitoring of coliphages. Published by Elsevier B.V.

Possible impacts of sea level rise on disease transmission and potential adaptation strategies, a review.

PubMed

Dvorak, Ana C; Solo-Gabriele, Helena M; Galletti, Andrea; Benzecry, Bernardo; Malone, Hannah; Boguszewski, Vicki; Bird, Jason

2018-07-01

Sea levels are projected to rise in response to climate change, causing the intrusion of sea water into land. In flat coastal regions, this would generate an increase in shallow water covered areas with limited circulation. This scenario raises a concern about the consequences it could have on human health, specifically the possible impacts on disease transmission. In this review paper we identified three categories of diseases which are associated with water and whose transmission can be affected by sea level rise. These categories include: mosquitoborne diseases, naturalized organisms (Vibrio spp. and toxic algae), and fecal-oral diseases. For each disease category, we propose comprehensive adaptation strategies that would help minimize possible health risks. Finally, the City of Key West, Florida is analyzed as a case study, due to its inherent vulnerability to sea level rise. Current and projected adaptation techniques are discussed as well as the integration of additional recommendations, focused on disease transmission control. Given that sea level rise will likely continue into the future, the promotion and implementation of positive adaptation strategies is necessary to ensure community resilience. Copyright © 2018 Elsevier Ltd. All rights reserved.

Water Utility Management Strategies in Turkey: The current situation and the challenges

NASA Astrophysics Data System (ADS)

Alp, E.; Aksoy, M. N.; Koçer, B.

2013-12-01

As the effects of climate change becomes more prominent, current challenges related to water and wastewater management is becoming more serious. Providing water that satisfies environmental and safety standards in terms of quantity and quality is needed to maintain human life without compromising the need of future generations. Besides providing safe and affordable water, necessary treatment should be achieved according to several important factors such as receiving body standards, discharge standards, water reuse options. Therefore, management of water becomes more crucial than ever that states have to provide accessibility of safe water with affordable cost to its citizens with the means of effective utility management, including water treatment facilities, wastewater treatment facilities, water supply facilities and water distribution systems. Water utilities encounter with several challenges related to cost, infrastructure, population, legislation, workforce and resource. This study aims to determine the current situation and the necessary strategies to improve utility management in Turkish municipalities in a sustainable manner. US Environment Protection Agency (EPA) has formed a tool on effective utility management that assists utilities to provide a solution for both current and future challenges. In this study, we used EPA's guidelines and developed a survey consists of 60 questions under 10 sub-topics (Product Quality, Employee & Leadership Development, Stakeholder Understanding & Support, Operational Optimization, Infrastructure Stability, Financial Viability, Community Sustainability, Customer Satisfaction, Operational Resiliency, and Water Resource Adequacy). This survey was sent to the managers of 25 metropolitan municipalities in Turkey to assess the current condition of municipalities. After the evaluation of the survey results for each topic, including the importance given by managers, facilities were rated according to their level of achievement. The scores were given for Rate Achievement from 1 to 5 and Rank Importance from 1 to 10 to the survey outcomes for each topic. Then, rating and ranking matrix was constructed according to score ranges. Results show that Product Quality, Stakeholder Understanding & Support, Infrastructure Stability and Customer Satisfaction are the major topics that needs to be improved according to the utility managers in Turkey. According to the outcomes of the study, water losses and unbilled unmetered consumption of water appeared to be the most important issues with the utility management. The utility managers also think there is still room for improvement to satisfy the needs of the users. Even though the rehabilitation of the infrastructure is a costly investment, it can be compensated with the help of the increased revenues as a result of improvement in water loss and unbilled water use. Suggestions given as a result of this study aim to aid decision makers and local authorities to overcome the significant problems faced during management and to achieve a sustainable utility management.

Water level management of lakes connected to regulated rivers: An integrated modeling and analytical methodology

NASA Astrophysics Data System (ADS)

Hu, Tengfei; Mao, Jingqiao; Pan, Shunqi; Dai, Lingquan; Zhang, Peipei; Xu, Diandian; Dai, Huichao

2018-07-01

Reservoir operations significantly alter the hydrological regime of the downstream river and river-connected lake, which has far-reaching impacts on the lake ecosystem. To facilitate the management of lakes connected to regulated rivers, the following information must be provided: (1) the response of lake water levels to reservoir operation schedules in the near future and (2) the importance of different rivers in terms of affecting the water levels in different lake regions of interest. We develop an integrated modeling and analytical methodology for the water level management of such lakes. The data-driven method is used to model the lake level as it has the potential of producing quick and accurate predictions. A new genetic algorithm-based synchronized search is proposed to optimize input variable time lags and data-driven model parameters simultaneously. The methodology also involves the orthogonal design and range analysis for extracting the influence of an individual river from that of all the rivers. The integrated methodology is applied to the second largest freshwater lake in China, the Dongting Lake. The results show that: (1) the antecedent lake levels are of crucial importance for the current lake level prediction; (2) the selected river discharge time lags reflect the spatial heterogeneity of the rivers' impacts on lake level changes; (3) the predicted lake levels are in very good agreement with the observed data (RMSE ≤ 0.091 m; R2 ≥ 0.9986). This study demonstrates the practical potential of the integrated methodology, which can provide both the lake level responses to future dam releases and the relative contributions of different rivers to lake level changes.

Application of multiple isotopic and geochemical tracers for investigation of recharge, salinization, and residence time of water in the Souss-Massa aquifer, southwest of Morocco

USGS Publications Warehouse

Bouchaou, L.; Michelot, J.L.; Vengosh, A.; Hsissou, Y.; Qurtobi, M.; Gaye, C.B.; Bullen, T.D.; Zuppi, G.M.

2008-01-01

Groundwater and surface water in Souss-Massa basin in the west-southern part of Morocco is characterized by a large variation in salinity, up to levels of 37 g L-1. The high salinity coupled with groundwater level decline pose serious problems for current irrigation and domestic water supplies as well as future exploitation. A combined hydrogeologic and isotopic investigation using several chemical and isotopic tracers such as Br/Cl, ??18O, ??2H, 3H, 87Sr/86Sr, ??11B, and 14C was carried out in order to determine the sources of water recharge to the aquifer, the origin of salinity, and the residence time of water. Stable isotope, 3H and 14C data indicate that the high Atlas mountains in the northern margin of the Souss-Massa basin with high rainfall and low ??18O and ??2H values (-6 to -8??? and -36 to -50???) is currently constitute the major source of recharge to the Souss-Massa shallow aquifer, particularly along the eastern part of the basin. Localized stable isotope enrichments offset meteoric isotopic signature and are associated with high nitrate concentrations, which infer water recycling via water agricultural return flows. The 3H and 14C data suggest that the residence time of water in the western part of the basin is in the order of several thousands of years; hence old water is mined, particularly in the coastal areas. The multiple isotope analyses and chemical tracing of groundwater from the basin reveal that seawater intrusion is just one of multiple salinity sources that affect the quality of groundwater in the Souss-Massa aquifer. We differentiate between modern seawater intrusion, salinization by remnants of seawater entrapped in the middle Souss plains, recharge of nitrate-rich agricultural return flow, and dissolution of evaporate rocks (gypsum and halite minerals) along the outcrops of the high Atlas mountains. The data generated in this study provide the framework for a comprehensive management plan in which water exploitation should shift toward the eastern part of the basin where current recharge occurs with young and high quality groundwater. In contrast, we argued that the heavily exploited aquifer along the coastal areas is more vulnerable given the relatively longer residence time of the water and salinization processes in this part of the aquifer. ?? 2008 Elsevier B.V. All rights reserved.

Flood-inundation maps for the East Fork White River near Bedford, Indiana

USGS Publications Warehouse

Fowler, Kathleen K.

2014-01-01

Digital flood-inundation maps for an 1.8-mile reach of the East Fork White River near Bedford, Indiana (Ind.) were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Department of Transportation. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/ depict estimates of the areal extent and depth of flooding corresponding to selectedwater levels (stages) at USGS streamgage 03371500, East Fork White River near Bedford, Ind. Current conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/in/nwis/uv?site_no=03371500. In addition, information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that are often colocated with USGS streamgages, including the East Fork White River near Bedford, Ind. NWS-forecasted peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. For this study, flood profiles were computed for the East Fork White River reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relations at USGS streamgage 03371500, East Fork White River near Bedford, Ind., and documented high-water marks from the flood of June 2008. The calibrated hydraulic model was then used to determine 20 water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the highest stage of the current stage-discharge rating curve. The simulated water-surface profiles were then combined with a geographic information system (GIS) digital elevation model (DEM, derived from Light Detection and Ranging (LiDAR) data having a 0.593-foot vertical accuracy) in order to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage near Bedford, Ind., and forecasted stream stages from the NWS, provides emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for postflood recovery eforts.

Evaluation of water resources in part of central Texas

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

Baker, B.; Duffin, G.; Flores, R.

1990-01-01

Water resources in the Brazos, Red, Colorado, and Trinity River basins, in central Texas, were evaluated. In 1985 there was a little less than 81,000 acre-ft of groundwater pumped from all aquifers in the study area, with a little less than 77,000 acre-ft of groundwater pumped from the Trinity Group aquifer. Irrigation accounted for about 56% of all groundwater pumped. A serious problem associated with the development of groundwater from the Trinity Group aquifer is the decline of artesian pressure in areas of large groundwater withdrawals. Degradation of groundwater within the Antlers and Travis Peak Formations from oil-field brines andmore » organic material are problems in several counties. The deterioration of water qualify for the City of Blum has occurred over a 26-year period and is associated with water level declines in the Hensell Member of the Travis Peak Formation. The Woodbine Group yields good quality water at or near the outcrop; however, the residual sodium carbonate and percent sodium limits its use for irrigation, while high iron and fluoride content restricts its use for public supply. Existing surface reservoirs in the study area alone can supply 296,400 acre-ft of water under 2010 conditions. Nearly all of this water is either currently owned or under contract to supply current and future needs. An additional 176,000 acre-ft of surface water could become available with the development of the proposed Lake Bosque and Paluxy Reservoir projects and with reallocation of storage in existing Lakes Waco and Whitney. The amount of groundwater currently pumped exceeds the estimated annual effective recharge to the Trinity Group aquifer; the groundwater supply for the area will continue to be drawn from storage within the aquifer. 84 refs., 21 figs., 3 tabs.« less

Eddy formation and surface flow field in the Luzon Strait area during the summer of 2009

NASA Astrophysics Data System (ADS)

Liu, Ze; Hou, Yijun; Xie, Qiang

2015-09-01

The formation of mesoscale eddies and the structure of the surface flow field in the Luzon Strait area were examined using in-situ CTD data, Argo float data, and multi-satellite remote sensing data collected from May to August 2009. The results show that vigorous water exchange between Kuroshio water and South China Sea (SCS) water began to emerge over the 200 m water column throughout the strait. Based on an objective definition of surface currents, float A69 tracked an anti-cyclonic eddy southwest of Taiwan Island under a Lagrangian current measurement. The salinity inside the anti-cyclonic eddy was higher than in typical SCS water but lower than in Kuroshio mainstream water, indicating that this eddy was induced by Kuroshio frontal intrusion through the Luzon Strait and into the SCS. From hydrographic data, we propose that continuous horizontal diffusion with high-salinity characteristics in the subsurface layer could extend to 119°E or even further west. The high-temperature filament, large positive sea level anomaly and clockwise geostrophic current all confirmed the existence of this warm eddy in May and June. A strongly negative wind stress curl maintained the eddy until it died. The surface flow field during July and August was rather complicated. Float A83 described an east-west orientated shuttle run in the 20°N section that was not reported by previous studies. At the same time, float A80 indicated a Kuroshio bend into the north-central region of Luzon Strait but it did not cross 120.5°E. The water mass rejoining the Kuroshio mainstream from the southern tip of Taiwan Island was less saline, indicating an entrainment of water from SCS by the Kuroshio bend.

Conceptual model and numerical simulation of the groundwater-flow system of Bainbridge Island, Washington

USGS Publications Warehouse

Frans, Lonna M.; Bachmann, Matthew P.; Sumioka, Steve S.; Olsen, Theresa D.

2011-01-01

Groundwater is the sole source of drinking water for the population of Bainbridge Island. Increased use of groundwater supplies on Bainbridge Island as the population has grown over time has created concern about the quantity of water available and whether saltwater intrusion will occur as groundwater usage increases. A groundwater-flow model was developed to aid in the understanding of the groundwater system and the effects of groundwater development alternatives on the water resources of Bainbridge Island. Bainbridge Island is underlain by unconsolidated deposits of glacial and nonglacial origin. The surficial geologic units and the deposits at depth were differentiated into aquifers and confining units on the basis of areal extent and general water-bearing characteristics. Eleven principal hydrogeologic units are recognized in the study area and form the basis of the groundwater-flow model. A transient variable-density groundwater-flow model of Bainbridge Island and the surrounding area was developed to simulate current (2008) groundwater conditions. The model was calibrated to water levels measured during 2007 and 2008 using parameter estimation (PEST) to minimize the weighted differences or residuals between simulated and measured hydraulic head. The calibrated model was used to make some general observations of the groundwater system in 2008. Total flow through the groundwater system was about 31,000 acre-ft/ yr. The recharge to the groundwater system was from precipitation and septic-system returns. Groundwater flow to Bainbridge Island accounted for about 1,000 acre-ft/ yr or slightly more than 5 percent of the recharge amounts. Groundwater discharge was predominately to streams, lakes, springs, and seepage faces (16,000 acre-ft/yr) and directly to marine waters (10,000 acre-ft/yr). Total groundwater withdrawals in 2008 were slightly more than 6 percent (2,000 acre-ft/yr) of the total flow. The calibrated model was used to simulate predevelopment conditions, during which no groundwater pumping or secondary recharge occurred and currently developed land was covered by conifer forests. Simulated water levels in the uppermost aquifer generally were slightly higher at the end of 2008 than under predevelopment conditions, likely due to increased recharge from septic returns and reduced evapotranspiration losses due to conversion of land cover from forests to current conditions. Simulated changes in water levels for the extensively used sea-level aquifer were variable, although areas with declines between zero and 10 feet were common and generally can be traced to withdrawals from public-supply drinking wells. Simulated water-level declines in the deep (Fletcher Bay) aquifer between predevelopment and 2008 conditions ranged from about 10 feet in the northeast to about 25 feet on the western edge of the Island. These declines are related to groundwater withdrawals for public-supply purposes. The calibrated model also was used to simulate the possible effects of increased groundwater pumping and changes to recharge due to changes in land use and climactic conditions between 2008 and 2035 under minimal, expected, and maximum impact conditions. Drawdowns generally were small for most of the Island (less than 10 ft) for the minimal and expected impact scenarios, and were larger for the maximum impact scenario. No saltwater intrusion was evident in any scenario by the year 2035. The direction of flow in the deep Fletcher Bay aquifer was simulated to reverse direction from its predevelopment west to east direction to an east to west direction under the maximum impact scenario.

Responses of water environment to tidal flat reduction in Xiangshan Bay: Part II locally re-suspended sediment dynamics

NASA Astrophysics Data System (ADS)

Li, Li; Guan, Weibing; He, Zhiguo; Yao, Yanming; Xia, Yuezhang

2017-11-01

Xiangshan Bay is a semi-enclosed bay in China, in which tidal flats have been substantially reclaimed to support the development of local economies and society over previous decades. The loss of tidal flats has led to changes of tides and locally suspended sediment in the bay. The effects of tidal flat reduction on locally suspended sediment dynamics was investigated using a numerical model forced by tidal data and calibrated by observed tidal elevation and currents. The model satisfactorily reproduces observed water levels, currents, and suspended sediment concentration in the estuary, and therefore is subsequently applied to analyze the impact of tidal flat reclamation on locally suspended sediment transport. After the loss of the tidal flats from 1963 to 2010, the suspended sediment concentrations (SSC) at the bottom boundary layer were reduced/increased in the outer bay/tidal flat areas due to weakened tidal currents. In the inner bay, the SSC values near the bottom level increased from 1963 to 2003 due to the narrowed bathymetry, and then decreased from 2003 to 2010 because of the reduced tidal prism. The model scenarios suggest that: (1) a reduction of tidal flat areas appears to be the main factor for enhancing the transport of sediments up-estuary, due to the increased Eulerian velocity and tidal pumping; (2) A reduction of tidal flat areas impacts on spatial and temporal SSC distribution: reducing the SSC values in the water areas due to the reduced current; and (3) a tidal flat reduction influences the net sediment fluxes: lessening the erosion and inducing higher/lower landward/seaward sediment transportation.

2015 Groundwater Monitoring Report Project Shoal Area: Subsurface Correction Unit 447

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

Findlay, Rick

The Project Shoal Area in Nevada was the site of a 12-kiloton-yield underground nuclear test in 1963. Although the surface of the site has been remediated, investigation of groundwater contamination resulting from the test is still in the corrective action process. Annual sampling and hydraulic head monitoring are conducted at the site as part of the subsurface corrective action strategy. The corrective action strategy is currently focused on revising the site conceptual model (SCM) and evaluating the adequacy of the monitoring well network. Some aspects of the SCM are known; however, two major concerns are the uncertainty in the groundwatermore » flow direction and the cause of rising water levels in site wells west of the shear zone. Water levels have been rising in the site wells west of the shear zone since the first hydrologic characterization wells were installed in 1996. Although water levels in wells west of the shear zone continue to rise, the rate of increase is less than in previous years. The SCM will be revised, and an evaluation of the groundwater monitoring network will be conducted when water levels at the site have stabilized to the agreement of both the U.S. Department of Energy Office of Legacy Management and the Nevada Division of Environmental Protection.« less

Assessing chronic and climate-induced water risk through spatially distributed cumulative deficit measures: A new picture of water sustainability in India

NASA Astrophysics Data System (ADS)

Devineni, Naresh; Perveen, Shama; Lall, Upmanu

2013-04-01

India is a poster child for groundwater depletion and chronic water stress. Often, water sustainability is measured through an estimate of the difference between the average supply and demand in a region. However, water supply and demand are highly variable in time and space. Hence, measures of scarcity need to reflect temporal imbalances even for a fixed location. We introduce spatially distributed indices of water stress that integrate over time variations in water supply and demand. The indices reflect the maximum cumulative deficit in a regional water balance within year and across years. This can be interpreted as the amount that needs to be drawn from external storage (either aquifers or surface reservoirs or interarea transfers) to meet the current demand pattern given a variable climate and renewable water supply. A simulation over a long period of record (historical or projected) provides the ability to quantify risk. We present an application at a district level in India considering more than a 100 year data set of rainfall as the renewable supply, and the recent water use pattern for each district. Consumption data are available through surveys at the district level, and consequently, we use this rather than river basins as the unit of analysis. The rainfall endogenous to each district is used as a potentially renewable water supply to reflect the supply-demand imbalances directly at the district level, independent of potential transfers due to upstream-induced runoff or canals. The index is useful for indicating whether small or large surface storage will suffice, or whether the extent of groundwater storage or external transfers, or changes in demand are needed to achieve a sustainable solution. Implications of the analysis for India and for other applications are discussed.

Agent-Based Modelling of Agricultural Water Abstraction in Response to Climate, Policy, and Demand Changes: Results from East Anglia, UK

NASA Astrophysics Data System (ADS)

Swinscoe, T. H. A.; Knoeri, C.; Fleskens, L.; Barrett, J.

2014-12-01

Freshwater is a vital natural resource for multiple needs, such as drinking water for the public, industrial processes, hydropower for energy companies, and irrigation for agriculture. In the UK, crop production is the largest in East Anglia, while at the same time the region is also the driest, with average annual rainfall between 560 and 720 mm (1971 to 2000). Many water catchments of East Anglia are reported as over licensed or over abstracted. Therefore, freshwater available for agricultural irrigation abstraction in this region is becoming both increasingly scarce due to competing demands, and increasingly variable and uncertain due to climate and policy changes. It is vital for water users and policy makers to understand how these factors will affect individual abstractors and water resource management at the system level. We present first results of an Agent-based Model that captures the complexity of this system as individual abstractors interact, learn and adapt to these internal and external changes. The purpose of this model is to simulate what patterns of water resource management emerge on the system level based on local interactions, adaptations and behaviours, and what policies lead to a sustainable water resource management system. The model is based on an irrigation abstractor typology derived from a survey in the study area, to capture individual behavioural intentions under a range of water availability scenarios, in addition to farm attributes, and demographics. Regional climate change scenarios, current and new abstraction licence reforms by the UK regulator, such as water trading and water shares, and estimated demand increases from other sectors were used as additional input data. Findings from the integrated model provide new understanding of the patterns of water resource management likely to emerge at the system level.

Scaling issues in sustainable river basin management

NASA Astrophysics Data System (ADS)

Timmerman, Jos; Froebich, Jochen

2014-05-01

Sustainable river basin management implies considering the whole river basin when managing the water resources. Management measures target at dividing the water over different uses (nature, agriculture, industry, households) thereby avoiding calamities like having too much, too little or bad quality water. Water management measures are taken at the local level, usually considering the sub-national and sometimes national effects of such measures. A large part of the world's freshwater resources, however, is contained in river basins and groundwater systems that are shared by two or more countries. Sustainable river basin management consequently has to encompass local, regional, national and international scales. This requires coordination over and cooperation between these levels that is currently compressed into the term 'water governance' . Governance takes into account that a large number of stakeholders in different regimes (the principles, rules and procedures that steer management) contribute to policy and management of a resource. Governance includes the increasing importance of basically non-hierarchical modes of governing, where non-state actors (formal organizations like NGOs, private companies, consumer associations, etc.) participate in the formulation and implementation of public policy. Land use determines the run-off generation and use of irrigation water. Land use is increasingly determined by private sector initiatives at local scale. This is a complicating factor in the governance issue, as in comparison to former developments of large scale irrigation systems, planning institutions at state level have then less insight on actual water consumption. The water management regime of a basin consequently has to account for the different scales of water management and within these different scales with both state and non-state actors. The central elements of regimes include the policy setting (the policies and water management strategies), legal setting (national and international laws and agreements), the institutional setting (the formal networks), information management (the information collection and dissemination system), and financing systems (the public and private sources that cover the water management costs). These elements are usually designed for a specific level and are ideally aligned with the other levels. The presentation will go into detail on connecting the different elements of the water management regime between different levels as well as on the overarching governance issues that play a role and will present opportunities and limitations of the linking options.

Dynamic regulation of aquaporin-4 water channels in neurological disorders

PubMed Central

Hsu, Ying; Tran, Minh; Linninger, Andreas A.

2015-01-01

Aquaporin-4 water channels play a central role in brain water regulation in neurological disorders. Aquaporin-4 is abundantly expressed at the astroglial endfeet facing the cerebral vasculature and the pial membrane, and both its expression level and subcellular localization significantly influence brain water transport. However, measurements of aquaporin-4 levels in animal models of brain injury often report opposite trends of change at the injury core and the penumbra. Furthermore, aquaporin-4 channels play a beneficial role in brain water clearance in vasogenic edema, but a detrimental role in cytotoxic edema and exacerbate cell swelling. In light of current evidence, we still do not have a complete understanding of the role of aquaporin-4 in brain water transport. In this review, we propose that the regulatory mechanisms of aquaporin-4 at the transcriptional, translational, and post-translational levels jointly regulate water permeability in the short and long time scale after injury. Furthermore, in order to understand why aquaporin-4 channels play opposing roles in cytotoxic and vasogenic edema, we discuss experimental evidence on the dynamically changing osmotic gradients between blood, extracellular space, and the cytosol during the formation of cytotoxic and vasogenic edema. We conclude with an emerging picture of the distinct osmotic environments in cytotoxic and vasogenic edema, and propose that the directions of aquaporin-4-mediated water clearance in these two types of edema are distinct. The difference in water clearance pathways may provide an explanation for the conflicting observations of the roles of aquaporin-4 in edema resolution. PMID:26526878

Atmospheric CO2: principal control knob governing Earth's temperature.

PubMed

Lacis, Andrew A; Schmidt, Gavin A; Rind, David; Ruedy, Reto A

2010-10-15

Ample physical evidence shows that carbon dioxide (CO(2)) is the single most important climate-relevant greenhouse gas in Earth's atmosphere. This is because CO(2), like ozone, N(2)O, CH(4), and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO(2) and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state.

Cryptosporidium Propidium Monoazide-PCR, a Molecular Biology-Based Technique for Genotyping Viable Cryptosporidium Oocysts

EPA Science Inventory

Cryptosporidium is an important waterborne protozoan parasite that can cause severe diarrhea and death in the immunocompromised. Current methods to monitor for Cryptosporidium oocysts in water are microscopy-based USEPA Methods 1622 and 1623. These methods assess total levels o...

ASSESSING THE EFFECTS OF DICHLOROACETIC ACID (DCA) USING A MULTI-ENDPOINT MEDAKA ASSAY

EPA Science Inventory

In regulating the safety of water, EPA makes decisions on what chemical contaminants to regulate and at what levels. To make these decisions, the EPA needs hazard identification and dose-response information. Current rodent methods for generating required information have limita...

75 FR 60617 - Review and Approval of Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-01

... cease taking water at given flow levels are in fact abiding by passby limitations. In addition, the... notice than the current contiguous property owner requirement that is based on proximity, not science... conservative management approach helping to ensure that applications are supported by science. Rather than...

Moving forward on remote sensing of soil salinity at regional scale

USDA-ARS?s Scientific Manuscript database

Soil salinity undermines global agriculture by reducing crop yield and soil quality. Irrigation management can help control salinity levels within the root-zone. To best allocate water resources, accurate regional-scale inventories are needed. Two remote sensing approaches are currently used to moni...

Capacitance Based Moisture Sensing for Microgravity Plant Modules: Sensor Design and Considerations

NASA Technical Reports Server (NTRS)

Schaber, Chad L.; Nurge, Mark; Monje, Oscar

2011-01-01

Life support systems for growing plants in microgravity should strive for providing optimal growing conditions and increased automation. Accurately tracking soil moisture content can forward both of these aims, so an attempt was made to instrument a microgravity growth module currently in development, the VEGGIE rooting pillow, in order to monitor moisture levels. Two electrode systems for a capacitance-based moisture sensor were tested. Trials with both types of electrodes showed a linear correlation between observed capacitance and water content over certain ranges of moisture within the pillows. Overall, both types of the electrodes and the capacitance-based moisture sensor are promising candidates for tracking water levels for microgravity plant growth systems.