Global water resources affected by human interventions and climate change

PubMed Central

Haddeland, Ingjerd; Heinke, Jens; Biemans, Hester; Eisner, Stephanie; Flörke, Martina; Hanasaki, Naota; Konzmann, Markus; Ludwig, Fulco; Masaki, Yoshimitsu; Schewe, Jacob; Stacke, Tobias; Tessler, Zachary D.; Wada, Yoshihide; Wisser, Dominik

2014-01-01

Humans directly change the dynamics of the water cycle through dams constructed for water storage, and through water withdrawals for industrial, agricultural, or domestic purposes. Climate change is expected to additionally affect water supply and demand. Here, analyses of climate change and direct human impacts on the terrestrial water cycle are presented and compared using a multimodel approach. Seven global hydrological models have been forced with multiple climate projections, and with and without taking into account impacts of human interventions such as dams and water withdrawals on the hydrological cycle. Model results are analyzed for different levels of global warming, allowing for analyses in line with temperature targets for climate change mitigation. The results indicate that direct human impacts on the water cycle in some regions, e.g., parts of Asia and in the western United States, are of the same order of magnitude, or even exceed impacts to be expected for moderate levels of global warming (+2 K). Despite some spread in model projections, irrigation water consumption is generally projected to increase with higher global mean temperatures. Irrigation water scarcity is particularly large in parts of southern and eastern Asia, and is expected to become even larger in the future. PMID:24344275

Effects of prevailing winds on turbidity of a shallow estuary.

PubMed

Cho, Hyun Jung

2007-06-01

Estuarine waters are generally more turbid than lakes or marine waters due to greater algal mass and continual re-suspension of sediments. The varying effects of diurnal and seasonal prevailing winds on the turbidity condition of a wind-dominated estuary were investigated by spatial and statistical analyses of wind direction, water level, turbidity, chlorophyll a, and PAR (Photosynthetically Active Radiation) collected in Lake Pontchartrain, Louisiana, USA. The prolonged prevailing winds were responsible for the long-term, large-scale turbidity pattern of the estuary, whereas the short-term changes in wind direction had differential effects on turbidity and water level in varying locations. There were temporal and spatial changes in the relationship between vertical light attenuation coefficient (Kd) and turbidity, which indicate difference in phytoplankton and color also affect Kd. This study demonstrates that the effect of wind on turbidity and water level on different shores can be identified through system-specific analyses of turbidity patterns.

Effects of Prevailing Winds on Turbidity of a Shallow Estuary

PubMed Central

Cho, Hyun Jung

2007-01-01

Estuarine waters are generally more turbid than lakes or marine waters due to greater algal mass and continual re-suspension of sediments. The varying effects of diurnal and seasonal prevailing winds on the turbidity condition of a wind-dominated estuary were investigated by spatial and statistical analyses of wind direction, water level, turbidity, chlorophyll a, and PAR (Photosynthetically Active Radiation) collected in Lake Pontchartrain, Louisiana, USA. The prolonged prevailing winds were responsible for the long-term, large-scale turbidity pattern of the estuary, whereas the short-term changes in wind direction had differential effects on turbidity and water level in varying locations. There were temporal and spatial changes in the relationship between vertical light attenuation coefficient (Kd) and turbidity, which indicate difference in phytoplankton and color also affect Kd. This study demonstrates that the effect of wind on turbidity and water level on different shores can be identified through system-specific analyses of turbidity patterns. PMID:17617683

40 CFR 141.65 - Maximum residual disinfectant levels.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... 141.65 Section 141.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water... only ground water not under the direct influence of surface water must comply with this subpart...

40 CFR 141.65 - Maximum residual disinfectant levels.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... 141.65 Section 141.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water... only ground water not under the direct influence of surface water must comply with this subpart...

40 CFR 141.65 - Maximum residual disinfectant levels.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... 141.65 Section 141.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water... only ground water not under the direct influence of surface water must comply with this subpart...

40 CFR 141.65 - Maximum residual disinfectant levels.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... 141.65 Section 141.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water... only ground water not under the direct influence of surface water must comply with this subpart...

Reuse/disposal of agricultural drainage water with high levels of salinity and toxic trace elements in central California.

USDA-ARS?s Scientific Manuscript database

Agricultural drainage waters in the western San Joaquin Valley of Central California contain high levels of salts, boron (B) and selenium (Se). Discharge of the drainage water directly into the Kesterson Reservoir in 1980's was hazardous to plants and wildlife. To investigate the plausibility of usi...

Generation of multivariate near shore extreme wave conditions based on an extreme value copula for offshore boundary conditions.

NASA Astrophysics Data System (ADS)

Leyssen, Gert; Mercelis, Peter; De Schoesitter, Philippe; Blanckaert, Joris

2013-04-01

Near shore extreme wave conditions, used as input for numerical wave agitation simulations and for the dimensioning of coastal defense structures, need to be determined at a harbour entrance situated at the French North Sea coast. To obtain significant wave heights, the numerical wave model SWAN has been used. A multivariate approach was used to account for the joint probabilities. Considered variables are: wind velocity and direction, water level and significant offshore wave height and wave period. In a first step a univariate extreme value distribution has been determined for the main variables. By means of a technique based on the mean excess function, an appropriate member of the GPD is selected. An optimal threshold for peak over threshold selection is determined by maximum likelihood optimization. Next, the joint dependency structure for the primary random variables is modeled by an extreme value copula. Eventually the multivariate domain of variables was stratified in different classes, each of which representing a combination of variable quantiles with a joint probability, which are used for model simulation. The main variable is the wind velocity, as in the area of concern extreme wave conditions are wind driven. The analysis is repeated for 9 different wind directions. The secondary variable is water level. In shallow waters extreme waves will be directly affected by water depth. Hence the joint probability of occurrence for water level and wave height is of major importance for design of coastal defense structures. Wind velocity and water levels are only dependent for some wind directions (wind induced setup). Dependent directions are detected using a Kendall and Spearman test and appeared to be those with the longest fetch. For these directions, wind velocity and water level extreme value distributions are multivariately linked through a Gumbel Copula. These distributions are stratified into classes of which the frequency of occurrence can be calculated. For the remaining directions the univariate extreme wind velocity distribution is stratified, each class combined with 5 high water levels. The wave height at the model boundaries was taken into account by a regression with the extreme wind velocity at the offshore location. The regression line and the 95% confidence limits where combined with each class. Eventually the wave period is computed by a new regression with the significant wave height. This way 1103 synthetic events were selected and simulated with the SWAN wave model, each of which a frequency of occurrence is calculated for. Hence near shore significant wave heights are obtained with corresponding frequencies. The statistical distribution of the near shore wave heights is determined by sorting the model results in a descending order and accumulating the corresponding frequencies. This approach allows determination of conditional return periods. For example, for the imposed univariate design return periods of 100 years for significant wave height and 30 years for water level, the joint return period for a simultaneous exceedance of both conditions can be computed as 4000 years. Hence, this methodology allows for a probabilistic design of coastal defense structures.

Floodplain Condition and Water Framework Directive River Classification in England: Evidence of a Disconnect.

NASA Astrophysics Data System (ADS)

Bentley, S.

2017-12-01

The European Union Water Framework Directive came into force in October 2000 committing European Union member states to achieve Good Ecological Status for all water bodies. By 2015 29% of rivers across England had achieved this level suggesting that these watercourse units are now functioning well. This study utilises recently published land cover data for England clipped to the floodplain boundary as defined by the 100 year return period discharge to examine the state of valley bottom vegetation and function for these Good Status rivers. Agricultural use of floodplain areas is high with cereal and horticulture covering an average of 24% and pasture accounting for some 37% of the area. Maximum values increase to 77% and 92% respectively. In all cases wetland accounts for less than 2% of the floodplain and rough grassland averages 7%. Such significant and widespread alteration to floodplain vegetation character suggests that the ecological functioning of this component of the fluvial system has been severely negatively impacted calling into question the Water Framework Directive status level. This is a fault of the Water Framework Directive process which only explicitly evaluates the hydromorphological component of the fluvial system for high status rivers preferring to infer functioning from biological indicators that are focused on in-channel assessments. The fundamental omission of floodplain condition in the Water Framework Directive process will result in only partial achievement of the original goals of the Directive with the majority of Europe's floodplains remaining in a highly degraded, non-functional state.

Dynamics of water-table fluctuations in an upland between two prairie-pothole wetlands in North Dakota

USGS Publications Warehouse

Rosenberry, Donald O.; Winter, Thomas C.

1997-01-01

Data from a string of instrumented wells located on an upland of 55 m width between two wetlands in central North Dakota, USA, indicated frequent changes in water-table configuration following wet and dry periods during 5 years of investigation. A seasonal wetland is situated about 1.5 m higher than a nearby semipermanent wetland, suggesting an average ground water-table gradient of 0.02. However, water had the potential to flow as ground water from the upper to the lower wetland during only a few instances. A water-table trough adjacent to the lower semipermanent wetland was the most common water-table configuration during the first 4 years of the study, but it is likely that severe drought during those years contributed to the longevity and extent of the water-table trough. Water-table mounds that formed in response to rainfall events caused reversals of direction of flow that frequently modified the more dominant water-table trough during the severe drought. Rapid and large water-table rise to near land surface in response to intense rainfall was aided by the thick capillary fringe. One of the wettest summers on record ended the severe drought during the last year of the study, and caused a larger-scale water-table mound to form between the two wetlands. The mound was short in duration because it was overwhelmed by rising stage of the higher seasonal wetland which spilled into the lower wetland. Evapotranspiration was responsible for generating the water-table trough that formed between the two wetlands. Estimation of evapotranspiration based on diurnal fluctuations in wells yielded rates that averaged 3–5 mm day−1. On many occasions water levels in wells closer to the semipermanent wetland indicated a direction of flow that was different from the direction indicated by water levels in wells farther from the wetland. Misinterpretation of direction and magnitude of gradients between ground water and wetlands could result from poorly placed or too few observation wells, and also from infrequent measurement of water levels in wells.

Clean water, sanitation and diarrhoea in Indonesia: Effects of household and community factors.

PubMed

Komarulzaman, Ahmad; Smits, Jeroen; de Jong, Eelke

2017-09-01

Diarrhoea is an important health issue in low- and middle-income countries, including Indonesia. We applied a multilevel regression analysis on the Indonesian Demographic and Health Survey to examine the effects of drinking water and sanitation facilities at the household and community level on diarrhoea prevalence among children under five (n = 33,339). The role of the circumstances was explored by studying interactions between the water and sanitation variables and other risk factors. Diarrhoea prevalence was reported by 4820 (14.4%) children, who on average were younger, poorer and were living in a poorer environment. At the household level, piped water was significantly associated with diarrhoea prevalence (OR = 0.797, 95% CI: 0.692-0.918), improved sanitation had no direct effect (OR = 0.992, 95% CI: 0.899-1.096) and water treatment was not related to diarrhoea incidence (OR = 1.106, 95% CI: 0.994-1.232). At the community level, improved water coverage had no direct effect (OR = 1.002, 95% CI: 0.950-1.057) but improved sanitation coverage was associated with lower diarrhoea prevalence (OR = 0.917, 95% CI: 0.843-0.998). Our interaction analysis showed that the protective effects of better sanitation at the community level were increased by better drinking water at the community level. This illustrates the importance of improving both drinking water and sanitation simultaneously.

Simulated interaction between freshwater and saltwater and effects of ground-water pumping and sea-level change, lower Cape Cod aquifer system, Massachusetts

USGS Publications Warehouse

Masterson, John P.

2004-01-01

The U.S. Geological Survey, in cooperation with the National Park Service, Massachusetts Executive Office of Environmental Affairs, Cape Cod Commission, and the Towns of Eastham, Provincetown, Truro, and Wellfleet, began an investigation in 2000 to improve the understanding of the hydrogeology of the four freshwater lenses of the Lower Cape Cod aquifer system and to assess the effects of changing ground-water pumping, recharge conditions, and sea level on ground-water flow in Lower Cape Cod, Massachusetts. A numerical flow model was developed with the computer code SEAWAT to assist in the analysis of freshwater and saltwater flow. Model simulations were used to determine water budgets, flow directions, and the position and movement of the freshwater/saltwater interface. Model-calculated water budgets indicate that approximately 68 million gallons per day of freshwater recharge the Lower Cape Cod aquifer system with about 68 percent of this water moving through the aquifer and discharging directly to the coast, 31 percent flowing through the aquifer, discharging to streams, and then reaching the coast as surface-water discharge, and the remaining 1 percent discharging to public-supply wells. The distribution of streamflow varies greatly among flow lenses and streams; in addition, the subsurface geology greatly affects the position and movement of the underlying freshwater/saltwater interface. The depth to the freshwater/saltwater interface varies throughout the study area and is directly proportional to the height of the water table above sea level. Simulated increases in sea level appear to increase water levels and streamflows throughout the Lower Cape Cod aquifer system, and yet decrease the depth to the freshwater/saltwater interface. The resulting change in water levels and in the depth to the freshwater/saltwater interface from sea-level rise varies throughout the aquifer system and is controlled largely by non-tidal freshwater streams. Pumping from large-capacity municipal-supply wells 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. Kettle-hole ponds, such as Duck Pond in Wellfleet, that are near the top of a freshwater flow lens, appear to be more susceptible to changing pumping and recharge conditions than kettle-hole ponds closer to the coast or near discharge boundaries, such as the Herring River.

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.

Regional water table (2016) in the Mojave River and Morongo groundwater basins, southwestern Mojave Desert, California

USGS Publications Warehouse

Dick, Meghan; Kjos, Adam

2017-12-07

From January to April 2016, the U.S. Geological Survey (USGS), the Mojave Water Agency, and other local water districts made approximately 1,200 water-level measurements in about 645 wells located within 15 separate groundwater basins, collectively referred to as the Mojave River and Morongo groundwater basins. These data document recent conditions and, when compared with older data, changes in groundwater levels. A water-level contour map was drawn using data measured in 2016 that shows the elevation of the water table and general direction of groundwater movement for most of the groundwater basins. Historical water-level data stored in the USGS National Water Information System (https://waterdata.usgs.gov/nwis/) database were used in conjunction with data collected for this study to construct 37 hydrographs to show long-term (1930–2016) and short-term (1990–2016) water-level changes in the study area.

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.

Kansas environmental and resource study: A Great Plains model. Monitoring fresh water resources. [water quality of reservoirs

NASA Technical Reports Server (NTRS)

Yarger, H. L. (Principal Investigator); Mccauley, J. R.

1974-01-01

The author has identified the following significant results. Processing and analysis of CCT's for numerous ground truth supported passes over Kansas reservoirs has demonstrated that sun angle and atmospheric conditions are strong influences on water reflectance levels as detected by ERTS-1 and can suppress the contributions of true water quality factors. Band ratios, on the other hand, exhibit very little dependence on sun angle and sky conditions and thus are more directly related to water quality. Band ratio levels can be used to reliably determine suspended load. Other water quality indicators appear to have little or no affect on reflectance levels.

Impact of European Union Legislation On The Wash Catchment, U.k.

NASA Astrophysics Data System (ADS)

Daldorph, P.; Wheater, H.; Saunders, A.

A case study is presented which shows the impact of existing European Legislation (Urban Waste Water Directive, Nitrate Directive, Bathing Waters Directive, Habitats Directive) on aquatic nutrient concentrations in the 16112 km2 catchment area of The Wash in eastern England , including both the inland and coastal zones. Information is provided on the implementation process (administrative and economic) and the observed impacts of measures to reduce environmental nutrient levels. Impacts are compared with simulations of nutrients in the inland and coastal zones, and the modeling tools are further used to predict impacts of future management change, e.g. to meet possible requirements of the Water Framework Directive. The issues in setting future environmental targets and research needs to underpin this process are discussed in the context of developing river basin management plans to support the Common Implementation Strategy for the Water Framework Directive.

Seasonal changes in ground-water levels in the shallow aquifer near Hagerman and the Pecos River, Chaves County, New Mexico

USGS Publications Warehouse

Garn, H.S.

1988-01-01

The Pecos River near Hagerman in Chaves County, New Mexico, historically has been a gaining stream. In 1938, the slope of the water table in the shallow alluvial aquifer near Hagerman was toward the Pecos River. By 1950, a large water-table depression had formed in the alluvial aquifer southwest of Hagerman. Continued enlargement of this depression could reverse the direction of groundwater flow to the Pecos River. Water levels were measured during 1981-85 in wells along a section extending from the Pecos River to a point within the depression. Although the water-table depression has not caused a perennial change in direction of groundwater flow, it has caused a seasonal reversal in the slope of the water table between the river and the depression during the growing season when pumpage from the shallow aquifer is the greatest. (USGS)

Pre-treating water with non-thermal plasma

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

Cho, Young I.; Fridman, Alexander; Rabinovich, Alexander

The present invention consists of a method of pre-treatment of adulterated water for distillation, including adulterated water produced during hydraulic fracturing ("fracking") of shale rock during natural gas drilling. In particular, the invention is directed to a method of treating adulterated water, said adulterated water having an initial level of bicarbonate ion in a range of about 250 ppm to about 5000 ppm and an initial level of calcium ion in a range of about 500 ppm to about 50,000 ppm, said method comprising contacting the adulterated water with a non-thermal arc discharge plasma to produce plasma treated water havingmore » a level of bicarbonate ion of less than about 100 ppm. Optionally, the plasma treated water may be further distilled.« less

Towards tributyltin quantification in natural water at the Environmental Quality Standard level required by the Water Framework Directive.

PubMed

Alasonati, Enrica; Fettig, Ina; Richter, Janine; Philipp, Rosemarie; Milačič, Radmila; Sčančar, Janez; Zuliani, Tea; Tunç, Murat; Bilsel, Mine; Gören, Ahmet Ceyhan; Fisicaro, Paola

2016-11-01

The European Union (EU) has included tributyltin (TBT) and its compounds in the list of priority water pollutants. Quality standards demanded by the EU Water Framework Directive (WFD) require determination of TBT at so low concentration level that chemical analysis is still difficult and further research is needed to improve the sensitivity, the accuracy and the precision of existing methodologies. Within the frame of a joint research project "Traceable measurements for monitoring critical pollutants under the European Water Framework Directive" in the European Metrology Research Programme (EMRP), four metrological and designated institutes have developed a primary method to quantify TBT in natural water using liquid-liquid extraction (LLE) and species-specific isotope dilution mass spectrometry (SSIDMS). The procedure has been validated at the Environmental Quality Standard (EQS) level (0.2ngL(-1) as cation) and at the WFD-required limit of quantification (LOQ) (0.06ngL(-1) as cation). The LOQ of the methodology was 0.06ngL(-1) and the average measurement uncertainty at the LOQ was 36%, which agreed with WFD requirements. The analytical difficulties of the method, namely the presence of TBT in blanks and the sources of measurement uncertainties, as well as the interlaboratory comparison results are discussed in detail. Copyright © 2016 Elsevier B.V. All rights reserved.

Discharge and nutrient transport between lakes in a hydrologically complex area of Voyageurs National Park, Minnesota, 2010-2012

USGS Publications Warehouse

Christensen, Victoria G.; Wakeman, Eric; Maki, Ryan P.

2016-01-01

An acoustic Doppler velocity meter (ADVM) was deployed in the narrows between Namakan and Kabetogama Lakes in Voyageurs National Park, Minnesota, from November 3, 2010, through October 3, 2012. The ADVM can account for wind, seiche, and changing flow direction in hydrologically complex areas. The objectives were to (1) estimate discharge and document the direction of water flow, (2) assess whether specific conductance can be used to determine flow direction, and (3) document nutrient and chlorophyll a concentrations at the narrows. The discharge direction through the narrows was seasonal. Water generally flowed out of Kabetogama Lake and into Namakan Lake throughout the ice-covered season. During spring, water flow was generally from Namakan Lake to Kabetogama Lake. During the summer and fall, the water flowed in both directions, affected in part by wind. Water flowed into Namakan Lake 70% of water year 2011 and 56% of water year 2012. Nutrient and chlorophyll a concentrations were highest during the summer months when water-flow direction was unpredictable. The use of an ADVM was effective for assessing flow direction and provided flow direction under ice. The results indicated the eutrophic Kabetogama Lake may have a negative effect on the more pristine Namakan Lake. The results also provide data on the effects of the current water-level management plan and may help determine if adjustments are necessary to help protect the aquatic ecosystem of Voyageurs National Park.

Persistence and diversity of directional landscape connectivity improves biomass pulsing in expanding and contracting wetlands

USGS Publications Warehouse

Yurek, Simeon; DeAngelis, Donald L.; Trexler, Joel C.; Klassen, Stephen; Larsen, Laurel G.

2016-01-01

In flood-pulsed ecosystems, hydrology and landscape structure mediate transfers of energy up the food chain by expanding and contracting in area, enabling spatial expansion and growth of fish populations during rising water levels, and subsequent concentration during the drying phase. Connectivity of flooded areas is dynamic as waters rise and fall, and is largely determined by landscape geomorphology and anisotropy. We developed a methodology for simulating fish dispersal and concentration on spatially-explicit, dynamic floodplain wetlands with pulsed food web dynamics, to evaluate how changes in connectivity through time contribute to the concentration of fish biomass that is essential for higher trophic levels. The model also tracks a connectivity index (DCI) over different compass directions to see if fish biomass dynamics can be related in a simple way to topographic pattern. We demonstrate the model for a seasonally flood-pulsed, oligotrophic system, the Everglades, where flow regimes have been greatly altered. Three dispersing populations of functional fish groups were simulated with empirically-based dispersal rules on two landscapes, and two twelve-year time series of managed water levels for those areas were applied. The topographies of the simulations represented intact and degraded ridge-and-slough landscapes (RSL). Simulation results showed large pulses of biomass concentration forming during the onset of the drying phase, when water levels were falling and fish began to converge into the sloughs. As water levels fell below the ridges, DCI declined over different directions, closing down dispersal lanes, and fish density spiked. Persistence of intermediate levels of connectivity on the intact RSL enabled persistent concentration events throughout the drying phase. The intact landscape also buffered effects of wet season population growth. Water level reversals on both landscapes negatively affected fish densities by depleting fish populations without allowing enough time for them to regenerate. Testable, spatiotemporal predictions of the timing, location, duration, and magnitude of fish concentration pulses were produced by the model, and can be applied to restoration planning.

Comparison of Hydraulic Conductivity Determinations in Co-located Conventional and Direct-Push Monitoring Wells

DTIC Science & Technology

2011-03-08

pressure gauge on the pneumatic head and indicate the number of inches the water level was lowered in the well to induce the slug test. ERDC/CRREL...a pneumatic slug-test system and its major components. ERDC/CRREL TR-11-6 10 pressure gauge on the pneumatic head, which is graduated in inches...The water level changes induced by the slug test were measured with a 10-psi pressure transducer installed below the water level. An analog-to

Chemical, physical, and radiological quality of selected public water supplies in Florida, February-April 1980

USGS Publications Warehouse

Franks, Bernard J.; Irwin, G.A.

1981-01-01

Virtually all treated public water supplies in Florida meet the National Interim Primary and Secondary Drinking Water Regulations. These findings are based on a water-quality reconnaissance of 126 raw and treated public water supplies throughout the State during the period February through April 1980. Primary drinking water regulations maximum contaminant levels were rarely exceeded, although mercury (1 site), fluoride (2 sites), and radionuclides (3 sites) in water supplies were above established maximum contaminant levels. Dissolved solids, chloride, copper, manganese, iron, color, sulfate, and pH, were occasionally slightly in excess of the recommended maximum contaminant levels of the secondary drinking water regulation. The secondary regulations, however, pertain mainly to the esthetic quality of drinking water and not directly to public health aspects. (USGS)

Fluid dynamics in suspension-feeding blackfish.

PubMed

Sanderson, S L; Cech, J J; Patterson, M R

1991-03-15

Measurements of flow patterns and water velocities inside the oral cavity of blackfish (Orthodon microlepidotus), made with a fiberoptic endoscope and thermistor flow probe, revealed that gill-arch structures act in blackfish as barriers that direct particle-laden water to the mucus-covered roof of the oral cavity, where particles are retained. Gill-arch structures have previously been assumed to be the site of particle retention in suspension-feeding fishes. Water does not pass between these structures in blackfish, and they do not serve as filters that separate particles from the water. These results emphasize the importance of directly assessing flow velocity and direction inside the oral cavity of vertebrate suspension feeders, particularly at the level of the filtering elements.

Disentangling Puzzles of Spatial Scales and Participation in Environmental Governance—The Case of Governance Re-scaling Through the European Water Framework Directive

NASA Astrophysics Data System (ADS)

Newig, Jens; Schulz, Daniel; Jager, Nicolas W.

2016-12-01

This article attempts to shed new light on prevailing puzzles of spatial scales in multi-level, participatory governance as regards the democratic legitimacy and environmental effectiveness of governance systems. We focus on the governance re-scaling by the European Water Framework Directive, which introduced new governance scales (mandated river basin management) and demands consultation of citizens and encourages `active involvement' of stakeholders. This allows to examine whether and how re-scaling through deliberate governance interventions impacts on democratic legitimacy and effective environmental policy delivery. To guide the enquiry, this article organizes existing—partly contradictory—claims on the relation of scale, democratic legitimacy, and environmental effectiveness into three clusters of mechanisms, integrating insights from multi-level governance, social-ecological systems, and public participation. We empirically examine Water Framework Directive implementation in a comparative case study of multi-level systems in the light of the suggested mechanisms. We compare two planning areas in Germany: North Rhine Westphalia and Lower Saxony. Findings suggest that the Water Framework Directive did have some impact on institutionalizing hydrological scales and participation. Local participation appears generally both more effective and legitimate than on higher levels, pointing to the need for yet more tailored multi-level governance approaches, depending on whether environmental knowledge or advocacy is sought. We find mixed results regarding the potential of participation to bridge spatial `misfits' between ecological and administrative scales of governance, depending on the historical institutionalization of governance on ecological scales. Polycentricity, finally, appeared somewhat favorable in effectiveness terms with some distinct differences regarding polycentricity in planning vs. polycentricity in implementation.

Disentangling Puzzles of Spatial Scales and Participation in Environmental Governance-The Case of Governance Re-scaling Through the European Water Framework Directive.

PubMed

Newig, Jens; Schulz, Daniel; Jager, Nicolas W

2016-12-01

This article attempts to shed new light on prevailing puzzles of spatial scales in multi-level, participatory governance as regards the democratic legitimacy and environmental effectiveness of governance systems. We focus on the governance re-scaling by the European Water Framework Directive, which introduced new governance scales (mandated river basin management) and demands consultation of citizens and encourages 'active involvement' of stakeholders. This allows to examine whether and how re-scaling through deliberate governance interventions impacts on democratic legitimacy and effective environmental policy delivery. To guide the enquiry, this article organizes existing-partly contradictory-claims on the relation of scale, democratic legitimacy, and environmental effectiveness into three clusters of mechanisms, integrating insights from multi-level governance, social-ecological systems, and public participation. We empirically examine Water Framework Directive implementation in a comparative case study of multi-level systems in the light of the suggested mechanisms. We compare two planning areas in Germany: North Rhine Westphalia and Lower Saxony. Findings suggest that the Water Framework Directive did have some impact on institutionalizing hydrological scales and participation. Local participation appears generally both more effective and legitimate than on higher levels, pointing to the need for yet more tailored multi-level governance approaches, depending on whether environmental knowledge or advocacy is sought. We find mixed results regarding the potential of participation to bridge spatial 'misfits' between ecological and administrative scales of governance, depending on the historical institutionalization of governance on ecological scales. Polycentricity, finally, appeared somewhat favorable in effectiveness terms with some distinct differences regarding polycentricity in planning vs. polycentricity in implementation.

MODOPTIM: A general optimization program for ground-water flow model calibration and ground-water management with MODFLOW

USGS Publications Warehouse

Halford, Keith J.

2006-01-01

MODOPTIM is a non-linear ground-water model calibration and management tool that simulates flow with MODFLOW-96 as a subroutine. A weighted sum-of-squares objective function defines optimal solutions for calibration and management problems. Water levels, discharges, water quality, subsidence, and pumping-lift costs are the five direct observation types that can be compared in MODOPTIM. Differences between direct observations of the same type can be compared to fit temporal changes and spatial gradients. Water levels in pumping wells, wellbore storage in the observation wells, and rotational translation of observation wells also can be compared. Negative and positive residuals can be weighted unequally so inequality constraints such as maximum chloride concentrations or minimum water levels can be incorporated in the objective function. Optimization parameters are defined with zones and parameter-weight matrices. Parameter change is estimated iteratively with a quasi-Newton algorithm and is constrained to a user-defined maximum parameter change per iteration. Parameters that are less sensitive than a user-defined threshold are not estimated. MODOPTIM facilitates testing more conceptual models by expediting calibration of each conceptual model. Examples of applying MODOPTIM to aquifer-test analysis, ground-water management, and parameter estimation problems are presented.

Vertical-Deformation, Water-Level, Microgravity, Geodetic, Water-Chemistry, and Flow-Rate Data Collected During Injection, Storage, and Recovery Tests at Lancaster, Antelope Valley, California, September 1995 Through September 1998

DTIC Science & Technology

2002-01-01

63 Tiltmeter Network...71 34. Map showing locations of tiltmeters used to monitor the magnitude and direction of ground tilting associated with direct well injection...during cycle 2 at Lancaster, Antelope Valley, California .............................. 72 35. Photograph showing typical tiltmeter installation for

Water-level conditions in the upper Cape Fear aquifer, 1992-94, in parts of Bladen and Robeson counties, North Carolina

USGS Publications Warehouse

Strickland, Alfred Gerald

1995-01-01

Water-level measurements were made on a periodic basis in 16 wells throughout an area of about 730 square miles in Bladen and Robeson Counties, North Carolina, from September 1992 to October 1994. Water levels from the wells were used to construct a map of the potentiometric surface of the upper Cape Fear aquifer in the fall of 1994. This map can be used to infer the direction of ground-water movement in the aquifer. Withdrawals from wells at pumping centers, such as in the Tar Heel and Elizabethtown areas, has disrupted the natural pattern of ground-water flow. Ground water flows toward pumped wells resulting in cones of depression in the potentiometric surface. Water levels measured in 14 wells in 1992 and 1994 were used to estimate change in ground-water levels for the upper Cape Fear aquifer in the study area. During 1992-94, water-level declines occurred in the aquifer throughout much of the area as a result of pumping. The greatest decline was 90.6 feet in Bladen County.

WATER LEVEL AND OXYGEN DELIVERY/UTILIZATION IN POROUS SALT MARSH SEDIMENTS

EPA Science Inventory

Increasing terrestrial nutrient inputs to coastal waters is a global water quality issue worldwide, and salt marshes may provide a valuable nutrient buffer, either by direct removal or by smoothing out pulse inputs between sources and sensitive estuarine habitats. A major challen...

Persistent water level changes in a well near Parkfield, California, due to local and distant earthquakes

NASA Astrophysics Data System (ADS)

Roeloffs, Evelyn A.

1998-01-01

Coseismic water level rises in the 30-m deep Bourdieu Valley (BV) well near Parkfield, California, have occurred in response to three local and five distant earthquakes. Coseismic changes in static strain cannot explain these water level rises because (1) the well is insensitive to strain at tidal periods; (2) for the distant earthquakes, the expected coseismic static strain is extremely small; and (3) the water level response is of the incorrect sign for the local earthquakes. These water level changes must therefore be caused by seismic waves, but unlike seismic water level oscillations, they are monotonic, persist for days or weeks, and seem to be caused by waves with periods of several seconds rather than long-period surface waves. Other investigators have reported a similar phenomenon in Japan. Certain wells consistently exhibit this type of coseismic water level change, which is always in the same direction, regardless of the earthquake's azimuth or focal mechanism, and approximately proportional to the inverse square of hypocentral distance. To date, the coseismic water level rises in the B V well have never exceeded the seasonal water level maximum, although their sizes are relatively well correlated with earthquake magnitude and distance. The frequency independence of the well's response to barometric pressure in the frequency band 0.1 to 0.7 cpd implies that the aquifer is fairly well confined. High aquifer compressibility, probably due to a gas phase in the pore space, is the most likely reason why the well does not respond to Earth tides. The phase and amplitude relationships between the seasonal water level and precipitation cycles constrain the horizontal hydraulic diffusivity to within a factor of 4.5, bounding hypothetical earthquake-induced changes in aquifer hydraulic properties. Moreover, changes of hydraulic conductivity and/or diffusivity throughout the aquifer would not be expected to change the water level in the same direction at every time of the year. The first 2.5 days of a typical coseismic water level rise could be caused by a small coseismic discharge decrease at a point several tens of meters from the well. Alternatively, the entire coseismic water level signal could represent diffusion of an abrupt coseismic pore pressure increase within several meters of the well, produced by a mechanism akin to that of liquefaction. The coseismic water level changes in the BV well resemble, and may share a mechanism with, coseismic water level, stream discharge, and groundwater temperature changes at other locations where preearthquake changes have also been reported. No preearthquake changes have been observed at the BV well site, however.

Persistent water level changes in a well near Parkfield, California, due to local and distant earthquakes

USGS Publications Warehouse

Roeloffs, E.A.

1998-01-01

Coseismic water level rises in the 30-m deep Bourdieu Valley (BV) well near Parkfield, California, have occurred in response to three local and five distant earthquakes. Coseismic changes in static strain cannot explain these water level rises because (1) the well is insensitive to strain at tidal periods; (2) for the distant earthquakes, the expected coseismic static strain is extremely small; and (3) the water level response is of the incorrect sign for the local earthquakes. These water level changes must therefore be caused by seismic waves, but unlike seismic water level oscillations, they are monotonic, persist for days or weeks, and seem to be caused by waves with periods of several seconds rather than long-period surface waves. Other investigators have reported a similar phenomenon in Japan. Certain wells consistently exhibit this type of coseismic water level change, which is always in the same direction, regardless of the earthquake's azimuth or focal mechanism, and approximately proportional to the inverse square of hypocentral distance. To date, the coseismic water level rises in the BV well have never exceeded the seasonal water level maximum, although their sizes are relatively well correlated with earthquake magnitude and distance. The frequency independence of the well's response to barometric pressure in the frequency band 0.1 to 0.7 cpd implies that the aquifer is fairly well confined. High aquifer compressibility, probably due to a gas phase in the pore space, is the most likely reason why the well does not respond to Earth tides. The phase and amplitude relationships between the seasonal water level and precipitation cycles constrain the horizontal hydraulic diffusivity to within a factor of 4.5, bounding hypothetical earthquake-induced changes in aquifer hydraulic properties. Moreover, changes of hydraulic conductivity and/or diffusivity throughout the aquifer would not be expected to change the water level in the same direction at every time of the year. The first 2.5 days of a typical coseismic water level rise could be caused by a small coseismic discharge decrease at a point several tens of meters from the well. Alternatively, the entire coseismic water level signal could represent diffusion of an abrupt coseismic pore pressure increase within several meters of the well, produced by a mechanism akin to that of liquefaction. The coseismic water level changes in the BV well resemble, and may share a mechanism with, coseismic water level, stream discharge, and groundwater temperature changes at other locations where preearthquake changes have also been reported. No preearthquake changes have been observed at the BV well site, however.

Potentiometric Surfaces and Water-Level Trends in the Cockfield and Wilcox Aquifers of Southern and Northeastern Arkansas, 2006

USGS Publications Warehouse

Schrader, T.P.

2007-01-01

The Cockfield Formation of Claiborne Group and the Wilcox Group contain aquifers that provide sources of ground water in southern and northeastern Arkansas. In 2000, about 9.9 million gallons per day was withdrawn from the Cockfield Formation of Claiborne Group and about 22.2 million gallons per day was withdrawn from the Wilcox Group. Major withdrawals from the aquifers were for industrial and public water supplies. A study was conducted by the U.S. Geological Survey in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey to determine the water level associated with the aquifers in the Cockfield Formation of Claiborne Group and the Wilcox Group in southern and northeastern Arkansas. During February and March 2006, 56 water-level measurements were made in wells completed in the Cockfield aquifer and 59 water-level measurements were made in wells completed in the Wilcox aquifer, 16 in southwestern and 43 in northeastern Arkansas. This report presents the results as potentiometric-surface maps and as long-term water-level hydrographs. The regional direction of ground-water flow in the Cockfield Formation of Claiborne Group generally is towards the east and southeast, away from the outcrop, except in areas of intense ground-water withdrawals, such as western Drew County, southeastern Lincoln County, southwestern Calhoun County, and near Crossett in Ashley County. There are three cones of depression indicated by relatively low water-level altitudes in southeastern Lincoln County, southwestern Calhoun County, and near Crossett in Ashley County. The lowest water-level altitude measured was 44 feet above the National Geodetic Vertical Datum of 1929 in Lincoln County; the highest water-level altitude measured was 346 feet above the National Geodetic Vertical Datum of 1929 in Columbia County at the outcrop area. Hydrographs from 40 wells with historical water levels from 1986 to 2006 were evaluated using linear regression to calculate the annual rise or decline. Calhoun and Cleveland Counties have mean annual rises from 0.01 to 0.07 feet per year. Arkansas, Ashley, Bradley, Chicot, Columbia, Drew, Lincoln, and Union Counties have mean annual declines from 0.4 to 0.55 feet per year. Desha County has a mean annual decline of about 1.35 feet per year. The direction of ground-water flow in the southwestern study area of the Wilcox Group generally is south and east. The lowest water-level altitude measured in southwestern Arkansas was 147 feet above the National Geodetic Vertical Datum of 1929 near the Ouachita River in Clark County; the highest water-level altitude measured was 397 feet above the National Geodetic Vertical Datum of 1929 in the outcrop area of Hempstead County. The direction of ground-water flow in the northeastern study area of the Wilcox Group generally is south and east. The lowest water-level altitude measured in northeastern Arkansas was 120 feet above the National Geodetic Vertical Datum of 1929 near West Memphis in Crittenden County; the highest water-level altitude measured was 368 feet above the National Geodetic Vertical Datum of 1929 on Crowleys Ridge in Clay County. Hydrographs from 28 wells with historical water levels from 1986 to 2006 were evaluated using linear regression to calculate the annual rise or decline. All 28 wells showed an annual decline from 1986 to 2006. Craighead, Greene, Mississippi, and Poinsett Counties have mean annual declines from 0.27 to 1.00 feet per year. Crittenden, Lee, and St. Francis Counties have mean annual declines from 1.39 to 1.64 feet per year.

Ultrasonic technique for detection of liquids in copper tubing process lines

NASA Astrophysics Data System (ADS)

Dudley, W. A.

1980-10-01

An ultrasonic pulse-echo method developed for semiquantitative measurement of liquid levels in copper tubing is described. This ultrasonic approach is of particular value when used as a pre-maintenance diagnostic tool in repairing process lines containing hazardous liquids. Performance tests show that water and similar liquids can be directly detected to fill levels as low as 1/16 in. For water fills below 1/16 in., direct level detection is impractical because of signal resolution limitations. However, this fill condition is indirectly measurable and is detected by the effect of observed degradation of the adjacent wall echo pattern. Fill conditions for liquids associated with high sound attenuation such as oil can be indirectly determined.

Excretion of arsenic (As) in urine of children, 7--11 years, exposed to elevated levels of As in the city water supply in Hermosillo, Sonora, Mexico

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

Wyatt, C.J.; Quiroga, V.L.; Acosta, R.T.O.

1998-07-01

Arsenic (As) is a common element in the environment with many industrial uses, but it also can be a contaminant in drinking water and present serious health concerns. Earlier studies on the quality of drinking water in the city of Hermosillo, Sonora, Mexico, showed high levels of As in water from wells located in the northern part of the city. Additionally a high positive correlation between the levels of Fluoride (F) and As in the same wells was found. Therefore, the objective of this study was to determine the excretion of As in children, 7--11 years of age, that hadmore » been exposed to elevated levels of As in their drinking water. Twenty-four-hour urine samples and a water sample taken directly in the home were collected from school age children living in two different areas with known high levels of As in their drinking water. A control group with normal levels of As in their water was also included.« less

A Powerful Method of Measuring Sea Wave Spectra and their Direction

NASA Astrophysics Data System (ADS)

Blasi, Christoph; Mai, Stephan; Wilhelmi, Jens; Zenz, Theodor; Barjenbruch, Ulrich

2014-05-01

Besides the need of precise measurements of water levels of the sea, there is an increasing demand for assessing waves in height and direction for different purposes like sea-wave modelling and coastal engineering. The design of coastal structures such as piles, breakwaters, and offshore structures like wind farms must take account of the direction of the impacting waves. To date, records of wave directions are scarce. The reason for this might be the high costs of purchasing and operating such measuring devices. These are usually buoys, which require regular maintenance. Against this background, the German Federal Institute of Hydrology (BfG) developed a low-cost directional sea-wave monitoring system that is based on commercially available liquid-level radar sensors. These sensors have the advantage that they have no contact to the fluid, i.e. the corrosive sea water. The newly developed device was tested on two sites. One is the tide gauge 'Borkum Südstrand' that is located in the southern North Sea off the island of Borkum. The other one is the 'Research Platform FINO1' approximately 45 km north of the island of Borkum. The main focus of these tests is the comparison of the data measured by the radar-based system with those of a conventional Directional Wave Rider Buoy. The general conditions at the testing sites are good for the tests. At the tide gauge 'Borkum Südstrand' waves propagate in different directions, strongly influenced by the morphological conditions like shallow waters of the Wadden Seas and the coast of the island of Borkum. Whereas on the open sea, at the site FINO1, the full physical conditions of the sea state, like heavy storms etc. play an important role. To determine and measure the direction of waves, the device has to be able to assess the wave movements in two dimensions. Therefore, an array of several radar sensors is required. Radar sensors are widely used and well established in measuring water levels, e.g. in tanks and basins. They operate by emitting a chain of electromagnetic pulses at a frequency of 26 GHz twice per second and, in turn, detect the backscatter information from the water surface. As the travelling time of each pulse is proportional to the distance between water surface and sensor, the height of the water surface can be easily calculated. To obtain the directional information of the sea state, all four radar sensors in the array have to collect simultaneously the wave profiles at fixed points. The Wave Rider Buoy works in a completely different way. Here, the wave height is calculated by the double integration of the measured vertical acceleration. By correlating the three-dimensional motion data, which are gained from gravity-stabilized vertical and horizontal accelerometers, the directional wave spectrum can be derived. Data of both devices were collected and analysed. During the hurricane Xaver, extreme water levels and heavy sea hit the North Sea coast on 5 and 6 December 2013. The radar array at the testing site FINO1 measured wave heights in the order of 15.5 meters. Furthermore, it was possible to detect significant wave heights, the mean wave direction, and the spread of the sea state. For the first time the accuracy of the wave height distribution could be determined as well.

Status of Ground-Water Levels and Storage Volume in the Equus Beds Aquifer Near Wichita, Kansas, January 2003-January 2006

USGS Publications Warehouse

Hansen, Cristi V.

2007-01-01

The Equus Beds aquifer northwest of Wichita, Kansas, was developed to supply water to Wichita residents and for irrigation in south-central Kansas. Ground-water pumping for city and agricultural use from the aquifer caused water levels to decline in a large part of the aquifer northwest of Wichita. Irrigation pumpage in the area increased substantially during the 1970s and 1980s and accelerated water-level declines. A period of water-level rises associated with greater-than-average precipitation and decreased city pumpage from the area began in 1993. An important factor in the decreased city pumpage was increased use of Cheney Reservoir as a water-supply source by the city of Wichita; as a result, city pumpage from the Equus Beds aquifer during 1993-2005 decreased to quantities similar to those pumped in the 1940s and went from being about 60 percent to about 40 percent of Wichita's water usage. Since 1995, the city also has been investigating the use of artificial recharge in the study area to meet future water-supply needs and to protect the aquifer from the intrusion of saltwater from sources to the west. During January 2006, the direction of ground-water flow in the Equus Beds aquifer in the area was generally from west to east, similar to the direction prior to development of the aquifer. Water-level changes since 1940 for the period January 2003-January 2006 ranged from a decline of more than 36 feet to a rise of more than 2 feet. Almost all wells in the area had small cumulative water-level rises from January 2003 to January 2006 and larger rises from October 1992 (period of maximum storage loss) to January 2006. The water-level rises from October 1992 to January 2006 probably are due principally to decreases in city pumpage, with increases in recharge due to increased precipitation during the period also a contributing factor. Irrigation pumpage increased during the period, so irrigation did not contribute to the rises in water levels between the beginning and end of the period. The storage volume change from October 1992 to January 2006 represents a recovery of about 55 percent of the storage volume previously lost between August 1940 and October 1992.

Water Management Strategy in Assessing the Water Scarcity in Northern Western Region of Nile Delta, Egypt

NASA Astrophysics Data System (ADS)

Mabrouk, Badr; Arafa, Salah; Gemajl, Khaled

2015-04-01

Sustainable development in the Nile Delta of Egypt is retarded by serious environmental problems, where land-use and land-cover of the region are subjected to continuous changes; including shoreline changes either by erosion or accretion, subsidence of the delta, as well as by sea level rise due to climate change. The current research attempts to; (1) study the vulnerability of the northern western region of the Nile Delta coastal zone to climate change/sea level rise while setting basic challenges, review adaptation strategies based on adaptation policy framework, and highlight recommended programs for preparedness to climate change, (2) study the scarcity of water resources in the area of study with review of the socioeconomic impacts and the critical need of establishing desalination plants with new standards assessing the environmental situation and population clusters, and (3) monitor of the brine water extracted from the desalination plants and injected to subsurface strata. This monitoring process is divided into 3 main directions: 1) studying the chemical characteristics of water extracted from the water desalinations plants qualitatively and quantitatively. 2) mapping the subsurface of which that brine water will be injected to it and the flow directions and effects using resistivity data, and 3) using GIS and suitable numerical models in order to study the effect, volume, flow of the brine water and its long term environmental impacts on the area. The results indicate that the area is particularly vulnerable to the impact of SLR, salt water intrusion, the deterioration of coastal tourism and the impact of extreme dust storms. This in turn will directly affect the agricultural productivity and human settlements in coastal zones. The paper presents different scenarios for water management and recommends the most suitable scenarios in order to establish a core for water management strategy in the region according to existing socio-economic and environmental situations. Key words: Nile Delta, climate change, socioeconomic, sea level rise, groundwater monitoring, GIS

Ground-water levels and flow directions in the glacial sediments and the Lockport Dolomite in southeastern Darke and northeastern Preble counties, Ohio, July 1998

USGS Publications Warehouse

Dumouchelle, Denise H.

1999-01-01

During the summer of 1997, the U.S. Environmental Protection Agency (USEPA) began an emergency removal action at the Lewisburg Drum Site in northern Preble County, Ohio.  The site is about 3 miles west-northwest of the village of Lewisburg.  The USEPA removed about 1,200 drums of waste ink from the site, as well as 2,500 cubic yards of contaminated soil and 100,000 gallons of ground water.  Because of the potential for off-site migration of ground-water contamination, USEPA sampled residential wells in the area; results from the samples collected by USEPA indicated that the quality of water in some privately owned wells may have been affected by contaminants from the site.  However, the directions of ground-water flow in the area were not known.  In 1998, the U.S. Geological Survey (USGS), in cooperation with the USEPA, measure water levels in the vicinity of the site.  This map will aid in the interpretation of the water-quality data collected by USEPA.

Implementation of Theeuropeanwater Framework Directive In France: New Challenges For River Basin Organisat Ion, Planning and Participation

NASA Astrophysics Data System (ADS)

Allain, S.

The European Water Framework Directive (2000/60/EC) establishes a system of participatory river basin planning for national and international basins. The French institutional framework for water management is already very close to this system: the 1964 Water Law actually set up basin bodies, the Agences de l'Eau ("Water Agencies"), at the level of large river basins, and multipartite basin commissions, the Comités de Bassin ("River Basin Authorities"), in order to monitor the Agences de l'Eau's policies; besides, the 1992 Water Law created a planning procedure at this level, the Schéma Directeur d'Aménagement et de Gestion des Eaux (SDAGE : "General Water Management Plan"), aiming to determine general orientations for the management of water resources and having to be defined by the Comités de Bassin. At first glance therefore, the implementation of the European Water Framework Directive should not raise a lot of problems in France. However, a quick analysis of the current situation shows that it is not so obvious : if the French Water Policy set up two basin organisations, neither of them deals concretely with the management of the water resources, and the implementation of water management plans depends on many stakeholders; the SDAGE itself only partially meets the demands of the Directive, regarding e. g. the economic analysis; finally, in spite of the creation of multipartite basin commissions, the public participation is very restricted. Such an analysis leads to pay more attention to the relations to establish between organisation, planning and participation at the level of large river basins. An analysis of other elements of the French institutional framework can help us in this way : another planning procedure was actually created by the 1992 Water Law, the Schéma d'Aménagement et de Gestion des Eaux (SAGE : "Water Management Plan"), aiming to fix general objectives to manage the water resources at the level of small river basins, and having to be defined and implemented by a new tripartite entity, the Commission Locale de l'Eau (CLE : Local Water Commission), which can be considered as a real river basin organisation; an empirical analysis of the implementation of such a procedure can offer therefore many new insights and the paper will present the results of an analysis of 10 case studies. But it will be also necessary to put such an experience side by side with the political will to develop public debates and to extend the roles of the Commission Nationale du Débat Public ("Public Debate National Commission").

Water, Water Everywhere, But....Notes for the Teacher, Report Writing Directions and Experiments.

ERIC Educational Resources Information Center

Jacobson, Cliff

Provided in this teaching package are materials that clearly and simply unveil the mysteries of water pollution. Materials, written on an approximate seventh-grade level, include: (1) a student reading unit; (2) water quality factors pamphlet; (3) experiments; and (4) teacher's guide to field testing a local waterway. The student reading unit is…

DEVELOPMENT OF A RESEARCH STRATEGY FOR INTEGRATED TECHNOLOGY-BASED-TOXICOLOGICAL AND CHEMICAL EVALUATION OF COMPLEX MIXTURES OF DRINKING WATER DISINFECTION BYPRODUCTS

EPA Science Inventory

Chemical disinfection of water is a major public health triumph of the 20th century. Dramatic decreases in both morbidity and mortality of water-borne diseases are a direct result of water disinfection. With these important public health benefits comes low-level, chronic ex...

Ground-water levels and direction of ground-water flow in the central part of Bernalillo County, New Mexico, summer 1983

USGS Publications Warehouse

Kues, Georginna E.

1986-01-01

In 1980, toxic chemicals were detected in water samples from wells in and near Albuquerque 's San Jose well field. At the request of the Environmental Improvement Division of the New Mexico Health and Environment Department, the U.S. Geological Survey conducted a study to determine groundwater levels and flow direction. Water levels were measured in 44 wells in a 64 sq mi area along the Rio Grande and adjacent areas during a period of near maximum municipal pumpage. Based on the altitude of screened interval, wells were grouped into shallow (screened internal above an altitude of 4,800 ft) or deep (screened internal below an altitude of 4,800 ft) zones. Groundwater in the shallow zone generally moves from north to south parallel to flow in the Rio Grande. Groundwater in the deep zone generally moves from the northwest to the east and southeast. A poorly developed cone of depression within the deep zone was present in the northeast. Water levels in wells were as much as 18 feet higher in the shallow zone than in the deep zone in the vicinity of the San Jose well field, indicating a downward gradient. (Author 's abstract)

Hydrogeology and leachate plume delineation at a closed municipal landfill, Norman, Oklahoma

USGS Publications Warehouse

Becker, Carol J.

2002-01-01

The City of Norman operated a solid-waste municipal landfill at two sites on the Canadian River alluvium in Cleveland County, Oklahoma from 1970 to 1985. The sites, referred to as the west and east cells of the landfill, were originally excavations in the unconsolidated alluvial deposits and were not lined. Analysis of ground-water samples indicate that leachate from the west cell is discharging into an adjacent abandoned river channel, referred to as the slough, and is migrating downgradient in ground water toward the Canadian River. The report describes the hydrogeologic features at the landfill, including the topography of the bedrock, water-level changes in the alluvial aquifer, and delineates the leachate plume using specific conductance data. The leading edge of the leachate plume along the 35-80 transect extended over 250 meters downgradient of the west cell. The leading edge of the leachate plume along the 40-SOUTH transect had moved about 60 meters from the west cell in a south-southwesterly direction and had not moved past the slough as of 1997. Specific conductance measurements exceeding 7,000 microsiemens per centimeter at site 40 indicate the most concentrated part of the plume remained in the upper half of the alluvial aquifer adjacent to the west cell. The direction of ground-water flow in the alluvial aquifer surrounding the landfill was generally north-northeast to south-southwest toward the river. However, between the west cell and the slough along the 40-SOUTH transect, head measurements indicate a directional change to the east and southeast toward a channel referred to as the sewage outfall. Near the 35-80 transect, at 0.5 meter below the water table and at the base of the aquifer, the direction of ground-water flow was south-southeast with a gradient of about 30 centimeters per 100 meters. Generally, ground-water levels in the alluvial aquifer were higher during the winter months and lower during summer months, due to a normal decrease in precipitation and increased evapotranspiration in the summer. Hydrographs show temporal water-level changes in ground water and the slough, indicating a hydrologic connection between the alluvial aquifer and the slough.

Detection of ultra-low levels of DNA changes by drinking water: epidemiologically important finding.

PubMed

Kumari, Parmila; Kamiseki, Meiko; Biyani, Manish; Suzuki, Miho; Nemoto, Naoto; Aita, Takuyo; Nishigaki, Koichi

2015-02-01

The safety of drinking water is essential to our health. In this context, the mutagenicity of water needs to be checked strictly. However, from the methodological limit, the lower concentration (less than parts per million) of mutagenicity could not be detected, though there have been of interest in the effect of less concentration mutagens. Here, we describe a highly sensitive mutation assay that detects mutagens at the ppb level, termed genome profiling-based mutation assay (GPMA). This consists of two steps; (i) Escherichia coli culture in the medium with/without mutagens and (ii) Genome profiling (GP) method (an integrated method of random PCR, temperature gradient gel electrophoresis and computer-aided normalization). Owing to high sensitivity of this method, very low concentration of mutagens in tap water could be directly detected without introducing burdensome concentration processes, enabling rapid measurement of low concentration samples. Less expectedly, all of the tap waters tested (22 samples) were shown to be significantly mutagenic while mineral waters were not. Resultantly, this article informs two facts that the GPMA method is competent to measure the mutagenicity of waters directly and the experimental results supported the former reports that the city tap waters contain very low level of mutagenicity reagent trihalomethanes. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Back-Analyses of Landfill Instability Induced by High Water Level: Case Study of Shenzhen Landfill

PubMed Central

Peng, Ren; Hou, Yujing; Zhan, Liangtong; Yao, Yangping

2016-01-01

In June 2008, the Shenzhen landfill slope failed. This case is used as an example to study the deformation characteristics and failure mode of a slope induced by high water levels. An integrated monitoring system, including water level gauges, electronic total stations, and inclinometers, was used to monitor the slope failure process. The field measurements suggest that the landfill landslide was caused by a deep slip along the weak interface of the composite liner system at the base of the landfill. The high water level is considered to be the main factor that caused this failure. To calculate the relative interface shear displacements in the geosynthetic multilayer liner system, a series of numerical direct shear tests were carried out. Based on the numerical results, the composite lining system simplified and the centrifuge modeling technique was used to quantitatively evaluate the effect of water levels on landfill instability. PMID:26771627

Potentiometric Surface of the Magothy Aquifer in Southern Maryland, September 2007

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Staley, Andrew W.

2009-01-01

This report presents a map showing the potentiometric surface of the Magothy aquifer in the Magothy Formation of Late Cretaceous age in Southern Maryland during September 2007. The map is based on water-level measurements in 69 wells. The highest measured water level was 85 feet above sea level near the northern boundary and outcrop area of the aquifer in the north-central part of Anne Arundel County. The potentiometric surface declined towards the south. Local gradients were directed toward the center of a cone of depression in the Waldorf area that developed in response to pumping. Measured ground-water levels were as low as 90 feet below sea level in the Waldorf area.

A direct immunoassay for detecting diatoms in groundwater as an indicator of the direct influence of surface water

USGS Publications Warehouse

Walker, C.E.; Schrock, R.M.; Reilly, T.J.; Baehr, A.L.

2005-01-01

Groundwater under the direct influence of surface water (GWUDISW) is of concern in communities where growing public demand on groundwater resources has resulted in increased withdrawals and hydraulic stress near surface water bodies. Under these conditions, contaminants such as methyl-tert butyl ether (MTBE) and biological materials have been detected in domestic wells. Other contaminants and pathogens associated with surface water are not routinely tested for in groundwater-supplied systems. To address the need for methods to easily identify potentially vulnerable supplies, a direct immunoassay for the quantitative detection of diatoms in raw water samples was developed as a measure of surface water influence on groundwater. Cell wall preparations from Nitzschia palea Ku??tzing, a freshwater diatom found throughout North America, were used to produce a polyclonal antibody that was applied in a direct enzyme-linked immunosorbent assay (ELISA) developed to detect the presence of N. palea cell wall components. The direct immunoassay allows detection at 500 cells L-1, a level similar to diatom concentrations observed in samples of groundwater collected near the test site. This investigation was the first attempt to utilize an ELISA as an indicator of surface water influence on groundwater. Further research is needed to develop more specific diatom-based monoclonal antibodies, determine cross-reactivity, and optimize sample processing and ELISA procedures for development of a standardized method. ?? Springer 2005.

A direct immunoassay for detecting diatoms in groundwater as an indicator of the direct influence of surface water

USGS Publications Warehouse

Walker, C.E.; Schrock, R.M.; Reilly, T.J.; Baehr, A.L.

2005-01-01

Groundwater under the direct influence of surface water (GWUDISW) is of concern in communities where growing public demand on groundwater resources has resulted in increased withdrawals and hydraulic stress near surface water bodies. Under these conditions, contaminants such as methyl-tert butyl ether (MTBE) and biological materials have been detected in domestic wells. Other contaminants and pathogens associated with surface water are not routinely tested for in groundwater-supplied systems. To address the need for methods to easily identify potentially vulnerable supplies, a direct immunoassay for the quantitative detection of diatoms in raw water samples was developed as a measure of surface water influence on groundwater. Cell wall preparations from Nitzschia palea Kützing, a freshwater diatom found throughout North America, were used to produce a polyclonal antibody that was applied in a direct enzyme-linked immunosorbent assay (ELISA) developed to detect the presence of N. palea cell wall components. The direct immunoassay allows detection at 500 cells L−1, a level similar to diatom concentrations observed in samples of groundwater collected near the test site. This investigation was the first attempt to utilize an ELISA as an indicator of surface water influence on groundwater. Further research is needed to develop more specific diatom-based monoclonal antibodies, determine cross-reactivity, and optimize sample processing and ELISA procedures for development of a standardized method.

Complex governance structures and incoherent policies: Implementing the EU water framework directive in Sweden.

PubMed

Söderberg, Charlotta

2016-12-01

Contemporary processes of environmental policymaking in general span over several territorial tiers. This also holds for the EU Water Framework Directive system of environmental quality standards (EQS), which are part of a complex multi-level institutional landscape, embracing both EU, national and sub-national level. Recent evaluations show that many EU member states, including Sweden, have not reached the ecological goals for water in 2015. Departing from theories on policy coherence and multi-level governance, this paper therefore analyses Swedish water governance as a case to further our understanding of policy implementation in complex governance structures: how does policy coherence (or the lack thereof) affect policy implementation in complex governance structures? To answer this question, the paper maps out the formal structure of the water governance system, focusing on power directions within the system, analyses policy coherence in Swedish water governance through mapping out policy conflicts between the EQS for water and other goals/regulations and explore how they are handled by national and sub-national water bureaucrats. The study concludes that without clear central guidance, 'good ecological status' for Swedish water will be difficult to achieve since incoherent policies makes policy implementation inefficient due to constant power struggles between different authorities, and since environmental goals are often overridden by economic and other societal goals. Further research is needed in order to explore if similar policy conflicts between water quality and other objectives occur in other EU member states and how bureaucrats handle such conflicts in different institutional settings. This study of the Swedish case indicates that the role of the state as a navigator and rudder-holder is important in order to improve policy implementation in complex governance structures - otherwise; bureaucrats risk being lost in an incoherent archipelago of ecological, social and economic goals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Direct injection GC method for measuring light hydrocarbon emissions from cooling-tower water.

PubMed

Lee, Max M; Logan, Tim D; Sun, Kefu; Hurley, N Spencer; Swatloski, Robert A; Gluck, Steve J

2003-12-15

A Direct Injection GC method for quantifying low levels of light hydrocarbons (C6 and below) in cooling water has been developed. It is intended to overcome the limitations of the currently available technology. The principle of this method is to use a stripper column in a GC to strip waterfrom the hydrocarbons prior to entering the separation column. No sample preparation is required since the water sample is introduced directly into the GC. Method validation indicates that the Direct Injection GC method offers approximately 15 min analysis time with excellent precision and recovery. The calibration studies with ethylene and propylene show that both liquid and gas standards are suitable for routine calibration and calibration verification. The sampling method using zero headspace traditional VOA (Volatile Organic Analysis) vials and a sample chiller has also been validated. It is apparent that the sampling method is sufficient to minimize the potential for losses of light hydrocarbons, and samples can be held at 4 degrees C for up to 7 days with more than 93% recovery. The Direct Injection GC method also offers <1 ppb (w/v) level method detection limits for ethylene, propylene, and benzene. It is superior to the existing El Paso stripper method. In addition to lower detection limits for ethylene and propylene, the Direct Injection GC method quantifies individual light hydrocarbons in cooling water, provides better recoveries, and requires less maintenance and setup costs. Since the instrumentation and supplies are readily available, this technique could easily be established as a standard or alternative method for routine emission monitoring and leak detection of light hydrocarbons in cooling-tower water.

Investigating summer flow paths in a Dutch agricultural field using high frequency direct measurements

NASA Astrophysics Data System (ADS)

Delsman, J. R.; Waterloo, M. J.; Groen, M. M. A.; Groen, J.; Stuyfzand, P. J.

2014-11-01

The search for management strategies to cope with projected water scarcity and water quality deterioration calls for a better understanding of the complex interaction between groundwater and surface water in agricultural catchments. We separately measured flow routes to tile drains and an agricultural ditch in a deep polder in the coastal region of the Netherlands, characterized by exfiltration of brackish regional groundwater flow and intake of diverted river water for irrigation and water quality improvement purposes. We simultaneously measured discharge, electrical conductivity and temperature of these separate flow routes at hourly frequencies, disclosing the complex and time-varying patterns and origins of tile drain and ditch exfiltration. Tile drainage could be characterized as a shallow flow system, showing a non-linear response to groundwater level changes. Tile drainage was fed primarily by meteoric water, but still transported the majority (80%) of groundwater-derived salt to surface water. In contrast, deep brackish groundwater exfiltrating directly in the ditch responded linearly to groundwater level variations and is part of a regional groundwater flow system. We could explain the observed salinity of exfiltrating drain and ditch water from the interaction between the fast-responding pressure distribution in the subsurface that determined groundwater flow paths (wave celerity), and the slow-responding groundwater salinity distribution (water velocity). We found water demand for maintaining water levels and diluting salinity through flushing to greatly exceed the actual sprinkling demand. Counterintuitively, flushing demand was found to be largest during precipitation events, suggesting the possibility of water savings by operational flushing control.

Determination of background levels on water quality of groundwater bodies: a methodological proposal applied to a Mediterranean River basin (Guadalhorce River, Málaga, southern Spain).

PubMed

Urresti-Estala, Begoña; Carrasco-Cantos, Francisco; Vadillo-Pérez, Iñaki; Jiménez-Gavilán, Pablo

2013-03-15

Determine background levels are a key element in the further characterisation of groundwater bodies, according to Water Framework Directive 2000/60/EC and, more specifically, Groundwater Directive 2006/118/EC. In many cases, these levels present very high values for some parameters and types of groundwater, which is significant for their correct estimation as a prior step to establishing thresholds, assessing the status of water bodies and subsequently identifying contaminant patterns. The Guadalhorce River basin presents widely varying hydrogeological and hydrochemical conditions. Therefore, its background levels are the result of the many factors represented in the natural chemical composition of water bodies in this basin. The question of determining background levels under objective criteria is generally addressed as a statistical problem, arising from the many aspects involved in its calculation. In the present study, we outline the advantages of applying two statistical techniques applied specifically for this purpose: (1) the iterative 2σ technique and (2) the distribution function, and examine whether the conclusions reached by these techniques are similar or whether they differ considerably. In addition, we identify the specific characteristics of each approach and the circumstances under which they should be used. Copyright © 2012 Elsevier Ltd. All rights reserved.

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…

Development and application of a spatial hydrology model of Okefenokee Swamp, Georgia

USGS Publications Warehouse

Loftin, C.S.; Kitchens, W.M.; Ansay, N.

2001-01-01

The model described herein was used to assess effects of the Suwannee River sill (a low earthen dam constructed to impound the Suwannee River within the Okefenokee National Wildlife Refuge to eliminate wildfires) on the hydrologic environment of Okefenokee Swamp, Georgia. Developed with Arc/Info Macro Language routines in the GRID environment, the model distributes water in the swamp landscape using precipitation, inflow, evapotranspiration, outflow, and standing water. Water movement direction and rate are determined by the neighborhood topographic gradient, determined using survey grade Global Positioning Systems technology. Model data include flow rates from USGS monitored gauges, precipitation volumes and water levels measured within the swamp, and estimated evapotranspiration volumes spatially modified by vegetation type. Model output in semi-monthly time steps includes water depth, water surface elevation above mean sea level, and movement direction and volume. Model simulations indicate the sill impoundment affects 18 percent of the swamp during high water conditions when wildfires are scarce and has minimal spatial effect (increasing hydroperiods in less than 5 percent of the swamp) during low water and drought conditions when fire occurrence is high but precipitation and inflow volumes are limited.

Measurements of aquifer-storage change and specific yield using gravity surveys

USGS Publications Warehouse

Pool, D.R.; Eychaner, J.H.

1995-01-01

Pinal Creek is an intermittent stream that drains a 200-square-mile alluvial basin in central Arizona. Large changes in water levels and aquifer storage occur in an alluvial aquifer near the stream in response to periodic recharge and ground-water withdrawals. Outflow components of the ground-water budget and hydraulic properties of the alluvium are well-defined by field measurements; however, data are insufficient to adequately describe recharge, aquifer-storage change, and specific-yield values. An investigation was begun to assess the utility of temporal-gravity surveys to directly measure aquifer-storage change and estimate values of specific yield.The temporal-gravity surveys measured changes in the differences in gravity between two reference stations on bedrock and six stations at wells; changes are caused by variations in aquifer storage. Specific yield was estimated by dividing storage change by water-level change. Four surveys were done between February 21, 1991, and March 31, 1993. Gravity increased as much as 158 microGal ± 1 to 6 microGal, and water levels rose as much as 58 feet. Average specific yield at wells ranged from 0.16 to 0.21, and variations in specific yield with depth correlate with lithologic variations. Results indicate that temporal-gravity surveys can be used to estimate aquifer-storage change and specific yield of water-table aquifers where significant variations in water levels occur. Direct measurement of aquifer-storage change can eliminate a major unknown from the ground-water budget of arid basins and improve residual estimates of recharge.

Comparison of self-reported and observed water contact in an S. mansoni endemic village in Brazil.

PubMed

Friedman, J F; Kurtis, J D; McGarvey, S T; Fraga, A L; Silveira, A; Pizziolo, V; Gazzinelli, G; LoVerde, P; Corrêa-Oliveira, R

2001-03-30

Estimates of exposure are critical for immuno-epidemiologic and intervention studies in human schistosomiasis. Direct observation of human water contact patterns is both costly and time consuming. To address these issues, we determined whether individuals residing in a Schistosoma mansoni endemic village in Brazil could accurately self-report their water contact patterns. We compared the results of a water contact questionnaire to the present gold standard, direct observation of water contact in 86 volunteers, aged 8--29. We administered a survey to estimate volunteers' frequency and type of water contact and directly measured each volunteers' water contact patterns during 5 weeks of detailed water contact observations. We found a poor correlation between self reported frequency of contact and directly observed exposure (rho=0.119, P=NS). The questionnaire data was supplemented by information about average body surface area of exposure and duration of contact for specific activities derived from observations of this cohort. This 'supplemented questionnaire' data was significantly correlated with their exposure index (rho=0.227, P=0.05). It provides a starting point from which questionnaires may develop to provide a more cost-effective and less labor intensive method of assessing water contact exposure at the level of the individual.

Potentiometric surface, 2013, and water-level differences, 1991-2013, of the Carrizo-Wilcox aquifer in northwest Louisiana

USGS Publications Warehouse

Fendick, Robert B.; Carter, Kayla

2015-01-01

This report presents data and maps that illustrate the potentiometric surface of the Carrizo-Wilcox aquifer during March–May 2013 and water-level differences from 1991 to 2013. The potentiometric surface map can be used for determining the direction of groundwater flow, hydraulic gradients, and effects of withdrawals on the groundwater resource. The rate of groundwater movement also can be estimated from the gradient when the hydraulic conductivity is applied. Water-level data collected for this study are stored in the USGS National Water Information System (NWIS) (http://waterdata.usgs.gov/nwis) and are on file at the USGS office in Baton Rouge, La.

Water levels, rapid vegetational changes, and the endangered Cape Sable seaside-sparrow

USGS Publications Warehouse

Nott, M.P.; Bass, O.L.; Fleming, D.M.; Killeffer, S.E.; Fraley, N.; Manne, L.; Curnutt, J.L.; Brooks, T.M.; Powell, R.; Pimm, S.L.

1998-01-01

The legally endangered Cape Sable seaside-sparrow (Ammodramus maritimus mirabilis) is restricted to short-hydroperiod, marl prairies within Florida's Everglades National Park and Big Cypress National Preserve. Marl prairies are typified by dense, mixed stands of graminoid species usually below 1 m in height, naturally inundated by freshwater for 3-7 months annually. Water levels affect the birds directly, by flooding their nests, and indirectly by altering the habitat on which they depend. Managed redistribution of water flows flooded nearly half of the sparrow's geographical range during several consecutive breeding seasons starting in 1993. Furthermore, these high water levels rapidly changed plant communities, so jeopardizing the sparrow's survival by reducing the availability of nesting habitat.

Toward Clean Water: A Guide to Citizen Action.

ERIC Educational Resources Information Center

Outen, Ronald, Ed.; Lawson, Simpson, Ed.

This guide identifies the major opportunities for participation under the 1976 Federal Water Pollution Control Act Amendments for citizens concerned with the improvement of water quality. The book is aimed primarily at fulfilling the direct needs of citizens at all levels. In addition to an explanation of the law and implementing regulations, this…

Implementation and use of direct-flow connections in a coupled ground-water and surface-water model

USGS Publications Warehouse

Swain, Eric D.

1994-01-01

The U.S. Geological Survey's MODFLOW finite-difference ground-water flow model has been coupled with three surface-water packages - the MODBRANCH, River, and Stream packages - to simulate surface water and its interaction with ground water. Prior to the development of the coupling packages, the only interaction between these modeling packages was that leakage values could be passed between MODFLOW and the three surface-water packages. To facilitate wider and more flexible uses of the models, a computer program was developed and added to MODFLOW to allow direct flows or stages to be passed between any of the packages and MODFLOW. The flows or stages calculated in one package can be set as boundary discharges or stages to be used in another package. Several modeling packages can be used in the same simulation depending upon the level of sophistication needed in the various reaches being modeled. This computer program is especially useful when any of the River, Stream, or MODBRANCH packages are used to model a river flowing directly into or out of wetlands in direct connection with the aquifer and represented in the model as an aquifer block. A field case study is shown to illustrate an application.

Relations Among River Stage, Rainfall, Ground-Water Levels, and Stage at Two Missouri River Flood-Plain Wetlands

USGS Publications Warehouse

Kelly, Brian P.

2001-01-01

The source of water is important to the ecological function of Missouri River flood-plain wetlands. There are four potential sources of water to flood-plain wetlands: direct flow from the river channel during high river stage, ground-water movement into the wetlands in response to river-stage changes and aquifer recharge, direct precipitation, and runoff from surrounding uplands. Concurrent measurements of river stage, rainfall, ground-water level, and wetland stage were compared for two Missouri River flood-plain wetlands located near Rocheport, Missouri, to characterize the spatial and temporal relations between river stage, rainfall, ground-water levels and wetland stage, determine the source of water to each wetland, and compare measured and estimated stage and ground-water levels at each site. The two sites chosen for this study were wetland NC-5, a non-connected, 50 feet deep scour constantly filled with water, formed during the flood of 1993, and wetland TC-1, a shallow, temporary wetland intermittently filled with water. Because these two wetlands bracket a range of wetland types of the Missouri River flood plain, the responses of other Missouri River wetlands to changes in river stage, rainfall, and runoff should be similar to the responses exhibited by wetlands NC-5 and TC-1. For wetlands deep enough to intersect the ground-water table in the alluvial aquifer, such as wetland NC-5, the ground-water response factor can estimate flood-plain wetland stage changes in response to known river-stage changes. Measured maximum stage and ground-water-level changes at NC-5 fall within the range of estimated changes using the ground-water response factor. Measured maximum ground-water-level changes at TC-1 are similar to, but consistently greater than the estimated values, and are most likely the result of alluvial deposits with higher than average hydraulic conductivity located between wetland TC-1 and the Missouri River. Similarity between ground-water level and stage hydrography at wetland NC-5 indicate that ground-water-level fluctuations caused by river-stage changes control the stage of wetland NC-5. A 2-day lag time exists between river-stage changes and ground water and stage changes at wetland NC-5. The lack of a measurable response of wetland NC-5 stage to rainfall indicate that rainfall is not a large source of water to wetland NC-5. Stage in wetland TC-1 only increased at high river stage in June and July 1999, and from runoff caused by local rainfall during the winter. The 2-day lag time between peak stages at wetland TC-1 and peak Missouri River stages compared to the 1-day lag time between Missouri River stage and ground-water peaks at wetland TC-1 indicates ground-water flow does not directly affect wetland stage at TC-1, but surface-water flow does affect wetland stage at TC-1 during high river stage. Comparing wetland TC-1 stage to potential water sources indicates the most likely explanation for the rise in stage at wetland TC-1 is surface runoff supplied via seepage through the levees and upward flow of ground water through alluvial deposits of higher hydraulic conductivity during high river stage. The rate of decrease in wetland TC-1 stage was limited by the rate at which ground-water level decreased. Stage response to rainfall at wetland TC-1 during the winter months and no response to greater rainfall amounts during spring and summer months indicate that evapotranspiration may limit the affect of rainfall on stage at wetland TC-1 during the growing season.

Changes in water levels and storage in the High Plains Aquifer, predevelopment to 2009

USGS Publications Warehouse

McGuire, V.L.

2011-01-01

The High Plains aquifer underlies 111.8 million acres (175,000 square miles) in parts of eight States - Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The area overlying the High Plains aquifer is one of the primary agricultural regions in the Nation. Water-level declines began in parts of the High Plains aquifer soon after the onset of substantial irrigation with groundwater from the aquifer (about 1950 and termed "predevelopment" in this fact sheet). By 1980, water levels in the High Plains aquifer in parts of Texas, Oklahoma, and southwestern Kansas had declined more than 100 feet (ft) (Luckey and others, 1981). In 1987, in response to declining water levels, Congress directed the U.S. Geological Survey (USGS), in collaboration with numerous Federal, State, and local water-resources entities, to assess and track water-level changes in the aquifer. This fact sheet summarizes changes in water levels and drainable water in storage in the High Plains aquifer from predevelopment to 2009. Drainable water in storage is the fraction of water in the aquifer that will drain by gravity and can be withdrawn by wells. The remaining water in the aquifer is held to the aquifer material by capillary forces and generally cannot be withdrawn by wells. Drainable water in storage is termed "water in storage" in this report. A companion USGS report presents more detailed and technical information about water-level and storage changes in the High Plains aquifer during this period (McGuire, 2011).

Water governance within Kenya's Upper Ewaso Ng'iro Basin: Assessing the performance of water projects

NASA Astrophysics Data System (ADS)

McCord, P. F.; Evans, T. P.; Dell'Angelo, J.; Gower, D.; McBride, L.; Caylor, K. K.

2013-12-01

Climate change processes are projected to change the availability and seasonality of streamflow with dramatic implications for irrigated agricultural systems. Within mountain environments, this alteration in water availability may be quite pronounced over a relatively short distance as upstream users with first access to river water directly impact the availability of water to downstream users. Livelihood systems that directly depend on river water for both domestic consumption and practices such as irrigated agriculture are particularly vulnerable. The Mount Kenya region is an exemplary case of a semi-arid upstream-downstream system in which water availability rapidly decreases and directly impacts the livelihoods of river water users existing across this steep environmental gradient. To effectively manage river water within these water-scarce environs, water projects have been established along the major rivers of the Mount Kenya region. These water projects are responsible for managing water within discrete sub-catchments of the region. While water projects develop rules that encourage the responsible use of water and maintenance of the project itself, the efficiency of water allocation to the projects' members remains unclear. This research analyzes water projects from five sub-catchments on the northwest slopes of Mount Kenya. It utilizes data from household surveys and water project management surveys as well as stream gauge data and flow measurements within individual water projects to assess the governance structure and performance of water projects. The performance of water projects is measured through a variety of household level metrics including: farm-level water flow and volume over time, mean and variability in maize yield, per capita crop productivity, household-level satisfaction with water availability, number of days where water volume was insufficient for irrigation, and quantity harvested compared with expected quantity harvested. We present results demonstrating the heterogeneity of these individual measures and discuss the influence of topography, network design, household behaviors and water governance on the overall performance of these water projects. This work is the foundation for an agent-based model of these water projects that investigates the impact of climate change and population pressure on sustained agricultural production in the region. Additionally, the study highlights the utility of pairing distinct fields of scholarship by utilizing both survey responses and hydrological data to study complex social-ecological systems. This pairing allows for insights regarding governance structures that are effectively managing river water in the present and helps to understand the structures that may be suitable for future water management.

Comparison of intracellular water content measurements by dark-field imaging and EELS in medium voltage TEM

NASA Astrophysics Data System (ADS)

Terryn, C.; Michel, J.; Kilian, L.; Bonhomme, P.; Balossier, G.

2000-09-01

Knowledge of the water content at the subcellular level is important to evaluate the intracellular concentration of either diffusible or non-diffusible elements in the physiological state measured by the electron microprobe methods. Water content variations in subcellular compartments are directly related to secretion phenomena and to transmembrane exchange processes, which could be attributed to pathophysiological states. In this paper we will describe in details and compare two local water measurement methods using analytical electron microscopy. The first one is based on darkfield imaging. It is applied on freeze-dried biological cryosections; it allows indirect measurement of the water content at the subcellular level from recorded maps of darkfield intensity. The second method uses electron energy loss spectroscopy. It is applied to hydrated biological cryosections. It is based on the differences that appear in the electron energy loss spectra of macromolecular assemblies and vitrified ice in the 0-30 eV range. By a multiple least squares (MLS) fit between an experimental energy loss spectrum and reference spectra of both frozen-hydrated ice and macromolecular assemblies we can deduce directly the local water concentration in biological cryosections at the subcellular level. These two methods are applied to two test specimens: human erythrocytes in plasma, and baker's yeast (Saccharomyses Cerevisiae) cryosections. We compare the water content measurements obtained by these two methods and discuss their advantages and drawbacks.

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.

Analysis of water levels in the Frenchman Flat area, Nevada Test Site

USGS Publications Warehouse

Bright, D.J.; Watkins, S.A.; Lisle, B.A.

2001-01-01

Analysis of water levels in 21 wells in the Frenchman Flat area, Nevada Test Site, provides information on the accuracy of hydraulic-head calculations, temporal water-level trends, and potential causes of water-level fluctuations. Accurate hydraulic heads are particularly important in Frenchman Flat where the hydraulic gradients are relatively flat (less than 1 foot per mile) in the alluvial aquifer. Temporal water-level trends with magnitudes near or exceeding the regional hydraulic gradient may have a substantial effect on ground-water flow directions. Water-level measurements can be adjusted for the effects of barometric pressure, formation water density (from water-temperature measurements), borehole deviation, and land-surface altitude in selected wells in the Frenchman Flat area. Water levels in one well were adjusted for the effect of density; this adjustment was significantly greater (about 17 feet) than the adjustment of water levels for barometric pressure, borehole deviation, or land-surface altitude (less than about 4 feet). Water-level measurements from five wells exhibited trends that were statistically and hydrologically significant. Statistically significant water-level trends were observed for three wells completed in the alluvial aquifer (WW-5a, UE-5n, and PW-3), for one well completed in the carbonate aquifer (SM-23), and for one well completed in the quartzite confining unit (Army-6a). Potential causes of water-level fluctuations in wells in the Frenchman Flat area include changes in atmospheric conditions (precipitation and barometric pressure), Earth tides, seismic activity, past underground nuclear testing, and nearby pumping. Periodic water-level measurements in some wells completed in the carbonate aquifer indicate cyclic-type water-level fluctuations that generally correlate with longer term changes (more than 5 years) in precipitation. Ground-water pumping fromthe alluvial aquifer at well WW-5c and pumping and discharge from well RNM-2s appear to cause water-level fluctuations in nearby observation wells. The remaining known sources of water-level fluctuations do not appear to substantially affect water-level changes (seismic activity and underground nuclear testing) or do not affect changes over a period of more than 1 year (barometric pressure and Earth tides) in wells in the Frenchman Flat area.

Improved water-level forecasting for the Northwest European Shelf and North Sea through direct modelling of tide, surge and non-linear interaction

NASA Astrophysics Data System (ADS)

Zijl, Firmijn; Verlaan, Martin; Gerritsen, Herman

2013-07-01

In real-time operational coastal forecasting systems for the northwest European shelf, the representation accuracy of tide-surge models commonly suffers from insufficiently accurate tidal representation, especially in shallow near-shore areas with complex bathymetry and geometry. Therefore, in conventional operational systems, the surge component from numerical model simulations is used, while the harmonically predicted tide, accurately known from harmonic analysis of tide gauge measurements, is added to forecast the full water-level signal at tide gauge locations. Although there are errors associated with this so-called astronomical correction (e.g. because of the assumption of linearity of tide and surge), for current operational models, astronomical correction has nevertheless been shown to increase the representation accuracy of the full water-level signal. The simulated modulation of the surge through non-linear tide-surge interaction is affected by the poor representation of the tide signal in the tide-surge model, which astronomical correction does not improve. Furthermore, astronomical correction can only be applied to locations where the astronomic tide is known through a harmonic analysis of in situ measurements at tide gauge stations. This provides a strong motivation to improve both tide and surge representation of numerical models used in forecasting. In the present paper, we propose a new generation tide-surge model for the northwest European Shelf (DCSMv6). This is the first application on this scale in which the tidal representation is such that astronomical correction no longer improves the accuracy of the total water-level representation and where, consequently, the straightforward direct model forecasting of total water levels is better. The methodology applied to improve both tide and surge representation of the model is discussed, with emphasis on the use of satellite altimeter data and data assimilation techniques for reducing parameter uncertainty. Historic DCSMv6 model simulations are compared against shelf wide observations for a full calendar year. For a selection of stations, these results are compared to those with astronomical correction, which confirms that the tide representation in coastal regions has sufficient accuracy, and that forecasting total water levels directly yields superior results.

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.

Developing Methods For Linking Surficial Aquifers With Localized Rainfall Data

NASA Astrophysics Data System (ADS)

Lafrenz, W. B.; van Gaalen, J. F.

2008-12-01

Water level hydrographs of the surficial aquifer can be evaluated to identify both the cause and consequence of water supply development. Rainfall, as a source of direct recharge and as a source of delayed or compounded recharge, is often the largest influence on surficial aquifer water level responses. It is clear that proximity of the rain gauge to the observation well is a factor in the degree of correlation, but in central Florida, USA, rainfall patterns change seasonally, with latitude, and with distance from the coast . Thus, for a location in central Florida, correlation of rain events with observed hydrograph responses depends on both distance and direction from an observation well to a rain gauge. In this study, we examine the use of extreme value analysis as a method of selecting the best rainfall data set for describing a given surficial aquifer monitor well. A surficial aquifer monitor well with a substantial suite of data is compared to a series of rainfall data sets from gauges ranging from meters to tens of kilometers in distance from the monitor well. The gauges vary in a wide range of directions from the monitor well in an attempt to identify both a method for rainfall gauge selection to be associated with the monitor well. Each rainfall gauge is described by a correlation coefficient with respect to the surficial aquifer water level data.

Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: I. Along-channel Water Level Variations, Pacific Ocean to Bonneville Dam

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

Jay, D. A.; Leffler, K.; Diefenderfer, Heida L.

This two-part paper provides comprehensive time and frequency domain analyses and models of along-channel water level variations in the 234km-long Lower Columbia River and Estuary (LCRE) and documents the response of floodplain wetlands thereto. In Part I, power spectra, continuous wavelet transforms, and harmonic analyses are used to understand the influences of tides, river flow, upwelling and downwelling, and hydropower operations ("power-peaking") on the water level regime. Estuarine water levels are influenced primarily by astronomical tides and coastal processes, and secondarily by river flow. The importance of coastal and tidal influences decreases in the landward direction, and water levels aremore » increasingly controlled by river flow variations at periods from ≤1 day to years. Water level records are only slightly non-stationary near the ocean, but become increasingly irregular upriver. Although astronomically forced tidal constituents decrease above the estuary, tidal fortnightly and overtide variations increase for 80-200km landward, both relative to major tidal constituents and in absolute terms.« less

Do shrubs reduce the adverse effects of grazing on soil properties?

USGS Publications Warehouse

Eldridge, David J.; Beecham, Genevieve; Grace, James B.

2015-01-01

Increases in the density of woody plants are a global phenomenon in drylands, and large aggregations of shrubs, in particular, are regarded as being indicative of dysfunctional ecosystems. There is increasing evidence that overgrazing by livestock reduces ecosystem functions in shrublands, but that shrubs may buffer the negative effects of increasing grazing. We examined changes in water infiltration and nutrient concentrations in soils under shrubs and in their interspaces in shrublands in eastern Australia that varied in the intensity of livestock grazing. We used structural equation modelling to test whether shrubs might reduce the negative effects of overgrazing on infiltration and soil carbon and nitrogen (henceforth ‘soil nutrients’). Soils under shrubs and subject to low levels of grazing were more stable and had greater levels of soil nutrients. Shrubs had a direct positive effect on soil nutrients; but, grazing negatively affected nutrients by increasing soil bulk density. Structural equation modelling showed that shrubs had a direct positive effect on water flow under ponded conditions but also enhanced water flow, indirectly, through increased litter cover. Any positive effects of shrubs on water flow under low levels of grazing waned at high levels of grazing. Our results indicate that shrubs may reduce the adverse effects of grazing on soil properties. Specifically, shrubs could restrict access to livestock and therefore protect soils and plants beneath their canopies. Low levels of grazing are likely to ensure the retention of soil water and soil carbon and nitrogen in shrubland soils.

Field Techniques for Estimating Water Fluxes Between Surface Water and Ground Water

USGS Publications Warehouse

Rosenberry, Donald O.; LaBaugh, James W.

2008-01-01

This report focuses on measuring the flow of water across the interface between surface water and ground water, rather than the hydrogeological or geochemical processes that occur at or near this interface. The methods, however, that use hydrogeological and geochemical evidence to quantify water fluxes are described herein. This material is presented as a guide for those who have to examine the interaction of surface water and ground water. The intent here is that both the overview of the many available methods and the in-depth presentation of specific methods will enable the reader to choose those study approaches that will best meet the requirements of the environments and processes they are investigating, as well as to recognize the merits of using more than one approach. This report is designed to make the reader aware of the breadth of approaches available for the study of the exchange between surface and ground water. To accomplish this, the report is divided into four chapters. Chapter 1 describes many well-documented approaches for defining the flow between surface and ground waters. Subsequent chapters provide an in-depth presentation of particular methods. Chapter 2 focuses on three of the most commonly used methods to either calculate or directly measure flow of water between surface-water bodies and the ground-water domain: (1) measurement of water levels in well networks in combination with measurement of water level in nearby surface water to determine water-level gradients and flow; (2) use of portable piezometers (wells) or hydraulic potentiomanometers to measure hydraulic gradients; and (3) use of seepage meters to measure flow directly. Chapter 3 focuses on describing the techniques involved in conducting water-tracer tests using fluorescent dyes, a method commonly used in the hydrogeologic investigation and characterization of karst aquifers, and in the study of water fluxes in karst terranes. Chapter 4 focuses on heat as a tracer in hydrological investigations of the near-surface environment.

Tides, and tidal and residual currents in Suisun and San Pablo bays, California; results of measurements, 1986

USGS Publications Warehouse

Gartner, J.W.; Yost, B.T.

1988-01-01

Current meter data collected at 11 stations and water level data collected at one station in Suisun and San Pablo Bays, California, in 1986 are compiled in this report. Current-meter measurements include current speed and direction, and water temperature and salinity (computed from temperature and conductivity). For each of the 19 current-meter records, data are presented in two forms. These are: (1) results of harmonic analysis; and (2) plots of tidal current speed and direction versus time and plots of temperature and salinity versus time. Spatial distribution of the properties of tidal currents are given in graphic form. In addition, Eulerian residual currents have been compiled by using a vector-averaging technique. Water level data are presented in the form of a time-series plot and the results of harmonic analysis. (USGS)

DEVELOPMENT OF A RESEARCH STRATEGY FOR INTEGRATED TECHNOLOGY-BASED TOXICOLOGICAL AND CHEMICAL EVALUATION OF COMPLEX MIXTURES OF DRINKING WATER DISINFECTION BYPRODUCTS

EPA Science Inventory

Chemical disinfection of water is a major public health triumph of the 20th century. Dramatic decreases in both morbidity and mortality of waterborne diseases are a direct result of water disinfection. With these important public health benefits comes low-level, chronic exposure ...

Water-level conditions in the upper Cape Fear Aquifer, 1994-98, in parts of Bladen and Robeson counties, North Carolina

USGS Publications Warehouse

Strickland, A.G.

1999-01-01

Water-level measurements were made on a periodic basis from October 1994 through November 1998 in 17 wells that tap the upper Cape Fear aquifer. The approximately 730-square-mile study area in Bladen and Robeson Counties is in the southern Coastal Plain of North Carolina. Water-level declines occurred in the aquifer throughout much of the area as a result of pumping during this period. The greatest decline was about 42 feet in Bladen County. Water levels from the wells in the fall of 1998 were used to construct a map of the potentiometric surface of the upper Cape Fear aquifer. This map can be used to infer the direction of ground-water movement in the aquifer. Withdrawals from wells at pumping centers, such as in the Tar Heel and Elizabethtown areas in Bladen County, have caused ground water to flow toward pumped wells, resulting in cones of depression in the potentiometric surface.

Development of high yielding photonic light delivery system for photodynamic therapy of esophageal carcinomas

NASA Astrophysics Data System (ADS)

Premasiri, Amaranath; Happawana, Gemunu; Rosen, Arye

2007-02-01

Photodynamic therapy (PDT) is an approved treatment modality for Barrett's and invasive esophageal carcinoma. Proper Combination of photosentizing agent, oxygen, and a specific wavelength of light to activate the photosentizing agents is necessary for the cytotoxic destruction of cancerous cells by PDT. As a light source expensive solid-state laser sources currently are being used for the treatment. Inexpensive semiconductor lasers have been suggested for the light delivery system, however packaging of semiconductor lasers for optimal optical power output is challenging. In this paper, we present a multidirectional direct water-cooling of semiconductor lasers that provides a better efficiency than the conventional unidirectional cooling. AlGaAsP lasers were tested under de-ionized (DI) water and it is shown that the optical power output of the lasers under the DI water is much higher than that of the uni-directional cooling of lasers. Also, in this paper we discuss how direct DI water-cooling can optimize power output of semiconductor lasers. Thereafter an optimal design of the semiconductor laser package is shown with the DI water-cooling system. Further, a microwave antenna is designed which is to be imprinted on to a balloon catheter in order to provide local heating of esophagus, leading to an increase in local oxygenation of the tumor to generate an effective level of singlet oxygen for cellular death. Finally the optimal level of light energy that is required to achieve the expected level of singlet oxygen is modeled to design an efficient PDT protocol.

The Politics of Extension Water Programming: Determining if Affiliation Impacts Participation

ERIC Educational Resources Information Center

Owens, Courtney T.; Lamm, Alexa J.

2017-01-01

Research has found levels of engagement in environmental behaviors and participation in Extension programming around environmental issues are directly associated with political affiliation. Democrat and Independent parties encourage members to vote for stricter environmental regulations, such as water conservation efforts, while Republicans…

OVERVIEW OF RESEARCH ON DEFINED AND COMPLEX MIXTURES OF DISINFECTION BYPRODUCTS

EPA Science Inventory

Decreased morbidity and mortality from water-borne diseases are a direct result of water disinfection. Concurrent with these important public health benefits is low-level, chronic exposure to a very large number of disinfection byproducts (DBPs), chemicals formed as a result of ...

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.

METHOD AND APPARATUS FOR CONTROLLING DIRECT-CYCLE NEUTRONIC REACTORS

DOEpatents

Reed, G.A.

1961-01-10

A control arrangement is offered for a boiling-water reactor. Boric acid is maintained in the water in the reactor and the amount in the reactor is controlled by continuously removing a portion of the water from the reactor, concentrating the boric acid by evaporating the water therefrom, returning a controlled amount of the acid to the reactor, and simultaneously controlling the water level by varying the rate of spent steam return to the reactor.

Hydrological, chemical, and biological characteristics of a prairie pothole wetland complex under highly variable climate conditions : the Cottonwood Lake area, east-central North Dakota

USGS Publications Warehouse

Winter, Thomas C.

2003-01-01

Geologic deposits in the Cottonwood Lake area consist largely of silty, clayey glacial till that contains numerous fractures and small, randomly distributed sand and gravel deposits. The sand deposits can have a substantial effect on groundwater flow between wetlands in the area and can cause some to drain while others have relatively stable inflow. Direct precipitation and runoff from snowmelt are the primary sources of water to the wetlands and evaporation accounts for the largest loss of water from the wetlands. The wetlands in the study area have a range of functions with respect to their interaction with ground water. Some of the seasonal wetlands recharge ground water and others recharge ground water and receive ground-water discharge. The semipermanent wetlands receive ground-water discharge much of the time, but some have reversals of flow between them and the groundwater system nearly every year. Ground-water flow toward the wetlands is caused by recharge in the uplands and by focused recharge near the wetland perimeters. Flow from the semipermanent wetlands to the ground-water system occurs when the wetland water levels are higher than the contiguous water table, resulting in bank storage, and when evapotranspiration directly from the ground-water system causes seepage around the wetland perimeters. Substantial climate variability during the study period caused the wetlands to range from being completely dry to having such high water levels that some of the wetlands merged to become large lakes.

The Water Level and Transport Regimes of the Lower Columbia River

NASA Astrophysics Data System (ADS)

Jay, D. A.

2011-12-01

Tidal rivers are vital, spatially extensive conduits of material from land to sea. Yet the tidal-fluvial regime remains poorly understood relative to the bordering fluvial and estuarine/coastal regimes with which it interacts. The 235km-long Lower Columbia River (LCR) consists of five zones defined by topographic constrictions: a 5km-long ocean-entrance, the lower estuary (15km), an energy-minimum (67km), the tidal river (142km), and a landslide zone (5km). Buoyant plume lift-off occurs within the entrance zone, which is dominated by tidal and wave energy. The lower estuary is strongly tidally, amplifies the semidiurnal tide, and has highly variable salinity intrusion. Tidal and fluvial influences are balanced in the wide energy-minimum, into which salinity intrudes during low-flow periods. It has a turbidity maximum and a dissipation minimum at its lower end, but a water-level variance minimum at its landward end. The tidal river shows a large increase in the ratio of fluvial-to-tidal energy in the landward direction and strong seasonal variations in tidal properties. Because tidal monthly water level variations are large, low waters are higher on spring than neap tides. The steep landslide zone has only weak tides and is the site of the most seaward hydropower dam. Like many dammed systems, the LCR has pseudo-tides: daily and weakly hydropower peaking waves that propagate seaward. Tidal constituent ratios vary in the alongchannel direction due to frictional non-linearities, the changing balance of dissipation vs. propagation, and power peaking. Long-term changes to the system have occurred due to climate change and direct human manipulation. Flood control, hydropower regulation, and diversion have reduced peak flows, total load and sand transport by ~45, 50 and 80%, respectively, causing a blue-shift in the flow and water level power spectra. Overbank flows have been largely eliminated through a redundant combination of diking and flow regulation. Export of sand to the ocean now occurs mainly through dredging, though fine sediment export may be higher than natural levels. Reduced sediment input and navigational development have reduced water levels in the upper tidal river by ~0.4/1.5m during low/high flow periods, impacting both navigation and shallow-water habitat availability. Tidal amplitudes have increased due both to increased coastal tides and reduced friction. This exacerbates difficulties with low-waters during fall neap tides. Climate-induced changes have so far had much less influence on system properties than human modifications. At present, regional sea level (RSL) rise and tectonic change are in balance, yielding no net sea level rise.

Rapid and Sensitive Enumeration of Viable Diluted Cells of Members of the Family Enterobacteriaceae in Freshwater and Drinking Water

PubMed Central

Baudart, Julia; Coallier, Josée; Laurent, Patrick; Prévost, Michèle

2002-01-01

Water quality assessment involves the specific, sensitive, and rapid detection of bacterial indicators and pathogens in water samples, including viable but nonculturable (VBNC) cells. This work evaluates the specificity and sensitivity of a new method which combines a fluorescent in situ hybridization (FISH) approach with a physiological assay (direct viable count [DVC]) for the direct enumeration, at the single-cell level, of highly diluted viable cells of members of the family Enterobacteriaceae in freshwater and drinking water after membrane filtration. The approach (DVC-FISH) uses a new direct detection device, the laser scanning cytometer (Scan RDI). Combining the DVC-FISH method on a membrane with Scan RDI detection makes it possible to detect as few as one targeted cell in approximately 108 nontargeted cells spread over the membrane. The ability of this new approach to detect and enumerate VBNC enterobacterial cells in freshwater and drinking water distribution systems was investigated and is discussed. PMID:12324357

Revisit: A Surprising Demonstration of Total Internal Reflection

ERIC Educational Resources Information Center

Lee, Jiwon; Cha, Yu Wha; Jung, Yeon Su; Oh, Eun Ju; Moon, Ye Lin; Kim, Jung Bog

2016-01-01

Melton demonstrated a surprising disappearance using total internal reflection. When he put a Florence flask filled with marbles into a water tank and looked straight down from directly above the flask, he was only able to see marbles above a certain water level. When he added more water into the tank above the top line of the marbles, all of the…

Extreme value theory applied to the definition of bathing water quality discounting limits.

PubMed

Haggarty, R A; Ferguson, C A; Scott, E M; Iroegbu, C; Stidson, R

2010-02-01

The European Community Bathing Water Directive (European Parliament, 2006) set compliance standards for bathing waters across Europe, with minimum standards for microbiological indicators to be attained at all locations by 2015. The Directive allows up to 15% of samples affected by short-term pollution episodes to be disregarded from the figures used to classify bathing waters, provided certain management criteria have been met, including informing the public of short-term water pollution episodes. Therefore, a scientifically justifiable discounting limit is required which could be used as a management tool to determine the samples that should be removed. This paper investigates different methods of obtaining discounting limits, focusing in particular on extreme value methodology applied to data from Scottish bathing waters. Return level based limits derived from threshold models applied at a site-specific level improved the percentage of sites which met at least the minimum required standard. This approach provides a method of obtaining limits which identify the samples that should be removed from compliance calculations, although care has to be taken in terms of the quantity of data which is removed. (c) 2009 Elsevier Ltd. All rights reserved.

A simple bubbling system for measuring radon (222Rn) gas concentrations in water samples based on the high solubility of radon in olive oil.

PubMed

Al-Azmi, D; Snopek, B; Sayed, A M; Domanski, T

2004-01-01

Based on the different levels of solubility of radon gas in organic solvents and water, a bubbling system has been developed to transfer radon gas, dissolving naturally in water samples, to an organic solvent, i.e. olive oil, which is known to be a good solvent of radon gas. The system features the application of a fixed volume of bubbling air by introducing a fixed volume of water into a flask mounted above the system, to displace an identical volume of air from an air cylinder. Thus a gravitational flow of water is provided without the need for pumping. Then, the flushing air (radon-enriched air) is directed through a vial containing olive oil, to achieve deposition of the radon gas by another bubbling process. Following this, the vial (containing olive oil) is measured by direct use of gamma ray spectrometry, without the need of any chemical or physical processing of the samples. Using a standard solution of 226Ra/222Rn, a lowest measurable concentration (LMC) of radon in water samples of 9.4 Bq L(-1) has been achieved (below the maximum contaminant level of 11 Bq L(-1)).

Global network of embodied water flow by systems input-output simulation

NASA Astrophysics Data System (ADS)

Chen, Zhanming; Chen, Guoqian; Xia, Xiaohua; Xu, Shiyun

2012-09-01

The global water resources network is simulated in the present work for the latest target year with statistical data available and with the most detailed data disaggregation. A top-down approach of systems inputoutput simulation is employed to track the embodied water flows associated with economic flows for the globalized economy in 2004. The numerical simulation provides a database of embodied water intensities for all economic commodities from 4928 producers, based on which the differences between direct and indirect water using efficiencies at the global scale are discussed. The direct and embodied water uses are analyzed at continental level. Besides, the commodity demand in terms of monetary expenditure and the water demand in terms of embodied water use are compared for the world as well as for three major water using regions, i.e., India, China, and the United States. Results show that food product contributes to a significant fraction for water demand, despite the value varies significantly with respect to the economic status of region.

78 FR 48068 - Topramezone; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-07

... from proteins in the diet). Inhibition of HPPD can result in elevated tyrosine levels in the blood, a... protein diet. This indicates that HPPD inhibitor in it of itself cannot easily overwhelm the tyrosine... from drinking water. The highest drinking water concentrations are expected to result from the direct...

Direct Measurement of Daily Evapotranspiration From a Deciduous Forest Using a Superconducting Gravimeter

NASA Astrophysics Data System (ADS)

Van Camp, M. J.; de Viron, O.; Pajot-Métivier, G.; Cazenave, F.; Watlet, A.; Dassargues, A.; Vanclooster, M.

2015-12-01

The conversion of liquid water into water vapor strongly controls the energy transfer between the Earth and the atmosphere, and plays one of the most important roles in the hydrological cycle. This process, called evapotranspiration (ET), deeply constraints the amount of green water in the total global water balance. However, assessing the ET from terrestrial ecosystems remains a key challenge in hydrology. We show that the liquid water mass losses can be directly inferred from continuous gravity measurements: as water evaporates and transpires from terrestrial ecosystems, the mass distribution varies through the system, changing its gravity field. Using continuous superconducting gravity measurements, we were able to identify a daily changes in gravity at the level of, or smaller than 10-10 g per day. This corresponds to 2.0 mm of water over an area of 50 ha.The strength of this method is its ability to ensure a direct, traceable and continuous monitoring of actual ET for years at the mesoscale (~50 ha) with a precision of a few tenths of mm of water. This paves the way for the development of the method in different land-use, land-cover and geological contexts, using superconducting and coming quantum gravimeters.

Spatial variability in the trends in extreme storm surges and weekly-scale high water levels in the eastern Baltic Sea

NASA Astrophysics Data System (ADS)

Soomere, Tarmo; Pindsoo, Katri

2016-03-01

We address the possibilities of a separation of the overall increasing trend in maximum water levels of semi-enclosed water bodies into associated trends in the heights of local storm surges and basin-scale components of the water level based on recorded and modelled local water level time series. The test area is the Baltic Sea. Sequences of strong storms may substantially increase its water volume and raise the average sea level by almost 1 m for a few weeks. Such events are singled out from the water level time series using a weekly-scale average. The trends in the annual maxima of the weekly average have an almost constant value along the entire eastern Baltic Sea coast for averaging intervals longer than 4 days. Their slopes are ~4 cm/decade for 8-day running average and decrease with an increase of the averaging interval. The trends for maxima of local storm surge heights represent almost the entire spatial variability in the water level maxima. Their slopes vary from almost zero for the open Baltic Proper coast up to 5-7 cm/decade in the eastern Gulf of Finland and Gulf of Riga. This pattern suggests that an increase in wind speed in strong storms is unlikely in this area but storm duration may have increased and wind direction may have rotated.

Interpretation of changes in water level accompanying fault creep and implications for earthquake prediction.

USGS Publications Warehouse

Wesson, R.L.

1981-01-01

Quantitative calculations for the effect of a fault creep event on observations of changes in water level in wells provide an approach to the tectonic interpretation of these phenomena. For the pore pressure field associated with an idealized creep event having an exponential displacement versus time curve, an analytic expression has been obtained in terms of exponential-integral functions. The pore pressure versus time curves for observation points near the fault are pulselike; a sharp pressure increase (or decrease, depending on the direction of propagation) is followed by more gradual decay to the normal level after the creep event. The time function of the water level change may be obtained by applying the filter - derived by A.G.Johnson and others to determine the influence of atmospheric pressure on water level - to the analytic pore pressure versus time curves. The resulting water level curves show a fairly rapid increase (or decrease) and then a very gradual return to normal. The results of this analytic model do not reproduce the steplike changes in water level observed by Johnson and others. If the procedure used to obtain the water level from the pore pressure is correct, these results suggest that steplike changes in water level are not produced by smoothly propagating creep events but by creep events that propagate discontinuously, by changes in the bulk properties of the region around the well, or by some other mechanism.-Author

Global energy consumption for direct water use

NASA Astrophysics Data System (ADS)

Liu, Y.; Hejazi, M. I.; Kim, S. H.; Kyle, P.; Davies, E. G.; Miralles, D. G.; Teuling, R.; He, Y.; Niyogi, D.

2015-12-01

Despite significant efforts to quantify the mutual inter-dependence of the water and energy sectors, global energy for water (EFW) remains poorly understood, resulting in biases in energy accounting that directly affect water and energy management and policy. We firstly evaluate the global energy consumption for direct water use from 1973 to 2012 with sectoral, regional and process-level details. Over the 40-year period, we detected multiple shifts in EFW by county and region. For example, we find that India, the Middle East and China have surpassed the United States as the three largest consumers of EFW since 2003, mostly because of rapid growth in groundwater-based irrigation, desalination, and industrial and municipal water use, respectively. Globally, EFW accounts for 1-3% of total primary energy consumption in 2010, of which 52% is surface water, 36% is groundwater, and 12% is non-fresh water. The sectoral allocation of EFW includes municipal (45%), industrial (29%), and agricultural use (26%), and process-level contributions are from source/conveyance (41%), water purification (19%), water distribution (13%) and wastewater treatment (22%). Our evaluation suggests that the EFW may increase in importance in the future due to growth in population and income, and depletion of surface and shallow aquifer water resources in water-scarce regions. We are incorporating this element into an integrated assessment model (IAM) and linking it back to energy balance within that IAM. By doing this, we will then explore the impacts of EFW on the global energy market (e.g., changes in the share of groundwater use and desalination), and the uncertainty of future EFW under different shared social pathway (SSP) and representative concentration pathway (RCP) scenarios, and consequences on the emission of greenhouse gases as well. We expect these EFW induced impacts will be considerable, and will then have significant implications for adaptive management and policy making.

Effects of a network of sand-storage dams on the hydrology on catchment scale

NASA Astrophysics Data System (ADS)

Ertsen, Maurits; Strohschein, Paul; Onencan, Abby; van de Giesen, Nick

2015-04-01

Water conservation is a high priority in the drier areas of sub-Saharan Africa. Storage of water from the rainy season to the dry season, or even from wet years to dry years is highly important. Small multi-purpose sub-surface water reservoirs recharged through infiltration are used to provide water for humans, livestock and crops in the Kitui region in Kenya. The groundwater dams obstruct the natural flow of water in wet seasons or periods, and provide storage of water during dry seasons or periods. This paper links the hydrology of the sand-storage dams to human agency. When is a dam a success in hydrological terms? When it provides water every year? Every two years? How many months? What happens in very dry years? Obviously, water use will decrease the water volume and thus the water level upstream of the dam, but to what extent typically depends on the amounts used compared to the size of the dam and the water use itself. Longer-term effects on groundwater levels to be expected depend strongly on the way the water is used. Household water use and river banks infiltration increasing seasonal storage can go hand in hand. However, when water in dams is used for higher water demanding activities such as (motorized) irrigation, the infiltration effect into banks may be minimal. A dam can also be "too effective" and decrease water availability for water users further downstream. It is unlikely, however, that an individual farmer will effect on the downstream users of the resources he/she is tapping, but a network of dams as in Kitui may have considerable effect. Measurements indicate that only about 2% to 3% of the total yearly runoff within the catchment directly associated with a single dam is stored in its reservoir. Therefore only this small percentage of the total flow of a seasonal river with dams is blocked. The paper will detail these general concepts with a case study of the Kiindu catchment. The hydrology of the Kiindu catchment is dependent on different aspects which influence each other. The physical environment determines the living conditions of the people directly and indirectly through the availability of water. The society on the other hand changes the physical environment directly by building sand dams or digging terraces directly and by the water use indirectly. Within the catchment, different sub-catchments show specific outcomes of this interaction. This means that even on a small scale of a catchment of some 20 kilometres, significant differences in water availability and quality can be found.

Challenges to Stakeholder Participation in Water Reuse for Irrigation in Jordan

NASA Astrophysics Data System (ADS)

Carr, Gemma; Potter, Rob; Nortcliff, Stephen

2010-05-01

Developing new water resources continues to be a challenge in water scarce regions and water reuse offers a sustainable means by which water availability can be maximised. In Jordan, treated domestic wastewater (reclaimed water) already provides a valuable contribution to the annual water budget. This resource is used for irrigation either directly around wastewater treatment plants, or indirectly after reclaimed water released from treatment plants has been transferred though natural waterways and blended with surface runoff. Direct reuse is employed for the irrigation of fodder crops such as barley or alfalfa, while indirect reuse is employed for the irrigation of high-value fruit and vegetable crops grown in the Jordan Valley, a major commercial agricultural area. In order to ensure water reuse is conducted successfully, it is essential that the benefits of reclaimed water (water availability, high nutrient content) are maximised while the potential risks (to human health, soil sustainability and agricultural yields) are minimised. Stakeholder participation in water reuse management decisions could raise the capacity of the water user (such as the farmer) to manage the risks without compromising the benefits of this resource. To investigate the extent to which stakeholders are participating in water reuse management, semi-structured interviews with farmers and institutional representatives were conducted in Jordan. A particular aim of the interviews was to explore the variation in participation between those stakeholders using reclaimed water directly and indirectly. The data collected during 56 interviews with Jordanian farmers showed that the farmers' perception and management of reclaimed water varied considerably between the indirect and direct users. The direct users had a greater level of satisfaction with the water (55 per cent of those asked described the water as "good water") and recognised that they were able to produce larger yields and raise their incomes through this resource. Direct users also felt that communication with the managers of the wastewater treatment plant was more effective and this enabled them to influence the final quality of the water they received (for example, through requesting a reduction in the chlorine concentration in the wastewater effluent due to the negative effect that chlorine has on crop quality). The indirect reuse farmers had a lower level of satisfaction with the reclaimed water (69 per cent of those asked described the water quality as bad). The interviews revealed that few farmers felt included in water resource management decisions and felt unable to discuss water quality concerns with government officials responsible for water distribution. The indirect reuse farmers seemed to be more concerned with water quality management at the individual farm level, through the installation of water filters to reduce the organic load of the water rather than through processes of lobbying or participatory involvement in decision-making to raise the quality of the water through top-down measures such as the enforcement of water quality legislation. The interviews with 29 organisational representatives drew attention to the sensitivity surrounding indirect water reuse which seems to inhibit open discussion of the topic. This is likely to be due to the nature of agriculture at the sites of indirect reuse. Institutional representatives appeared to be concerned with the risk of consumer rejection of produce grown with reclaimed water and the associated negative effects of rejection on agricultural income and employment. A strategy of reduced discussion seemed to be adopted in the attempt to minimise the potential for consumer rejection. The present research proposes that this strategy (adopted with the aim of protecting agriculture) could have the reverse effect though inhibiting the participation of farmers in water reuse planning and management (they are unable to take part in a process in which they are not recognised as being involved). Open discussion of reuse is necessary to accurately identify water quality requirements, drive appropriate legislation and subsequently lead to the enforcement of such legislation. This work shows that a major barrier to participation in water reuse management is the stakeholders' fear that consumer concerns over the use of "waste" resources in food production will reduce marketability. The extent of consumer concerns, in conjunction with stakeholders' perceptions of these concerns, is therefore an important area to be addressed in future research.

Determining return water levels at ungauged coastal sites: a case study for northern Germany

NASA Astrophysics Data System (ADS)

Arns, Arne; Wahl, Thomas; Haigh, Ivan D.; Jensen, Jürgen

2015-04-01

We estimate return periods and levels of extreme still water levels for the highly vulnerable and historically and culturally important small marsh islands known as the Halligen, located in the Wadden Sea offshore of the coast of northern Germany. This is a challenging task as only few water level records are available for this region, and they are currently too short to apply traditional extreme value analysis methods. Therefore, we use the Regional Frequency Analysis (RFA) approach. This originates from hydrology but has been used before in several coastal studies and is also currently applied by the local federal administration responsible for coastal protection in the study area. The RFA enables us to indirectly estimate return levels by transferring hydrological information from gauged to related ungauged sites. Our analyses highlight that this methodology has some drawbacks and may over- or underestimate return levels compared to direct analyses using station data. To overcome these issues, we present an alternative approach, combining numerical and statistical models. First, we produced a numerical multidecadal model hindcast of water levels for the entire North Sea. Predicted water levels from the hindcast are bias corrected using the information from the available tide gauge records. Hence, the simulated water levels agree well with the measured water levels at gauged sites. The bias correction is then interpolated spatially to obtain correction functions for the simulated water levels at each coastal and island model grid point in the study area. Using a recommended procedure to conduct extreme value analyses from a companion study, return water levels suitable for coastal infrastructure design are estimated continuously along the entire coastline of the study area, including the offshore islands. A similar methodology can be applied in other regions of the world where tide gauge observations are sparse.

Condensed Phase Membrane Introduction Mass Spectrometry with Direct Electron Ionization: On-line Measurement of PAHs in Complex Aqueous Samples

NASA Astrophysics Data System (ADS)

Termopoli, Veronica; Famiglini, Giorgio; Palma, Pierangela; Cappiello, Achille; Vandergrift, Gregory W.; Krogh, Erik T.; Gill, Chris G.

2016-02-01

Polycyclic aromatic hydrocarbons (PAHs) are USEPA regulated priority pollutants. Their low aqueous solubility requires very sensitive analytical methods for their detection, typically involving preconcentration steps. Presented is the first demonstrated `proof of concept' use of condensed phase membrane introduction mass spectrometry (CP-MIMS) coupled with direct liquid electron ionization (DEI) for the direct, on-line measurement of PAHs in aqueous samples. DEI is very well suited for the ionization of PAHs and other nonpolar compounds, and is not significantly influenced by the co-elution of matrix components. Linear calibration data for low ppb levels of aqueous naphthalene, anthracene, and pyrene is demonstrated, with measured detection limits of 4 ppb. Analytical response times (t10%-90% signal rise) ranged from 2.8 min for naphthalene to 4.7 min for pyrene. Both intra- and interday reproducibility has been assessed (<3% and 5% RSD, respectively). Direct measurements of ppb level PAHs spiked in a variety of real, complex environmental sample matrices is examined, including natural waters, sea waters, and a hydrocarbon extraction production waste water sample. For these spiked, complex samples, direct PAH measurement by CP-MIMS-DEI yielded minimal signal suppression from sample matrix effects (81%-104%). We demonstrate the use of this analytical approach to directly monitor real-time changes in aqueous PAH concentrations with potential applications for continuous on-line monitoring strategies and binding/adsorption studies in heterogeneous samples.

The value of long-term monitoring in the development of ground-water-flow models

USGS Publications Warehouse

Feinstein, Daniel T.; Hart, David J.; Krohelski, James T.

2004-01-01

As environmental issues have come to the forefront of public concern, so has the awareness of the importance of ground water in the overall water cycle and as a source of the Nation’s drinking water. Heightened interest has spawned a host of scientific enterprises (Taylor and Alley, 2001). Some activities are directed toward collection of water-level data and related information to monitor the physical and chemical state of the resource. Other activities are directed at interpretive studies undertaken, for example, to optimize the location of new water-supply wells or to protect rivers and lakes fed by ground water. An important type of interpretive study is the computer ground-water-flow model that inte- grates field data in a mathematical framework. Long-term, systematic collection of hydro- logic data is crucial to the construction and testing of ground-water models so that they can reproduce the evolution of flow systems and forecast future conditions. 

Geohydrologic reconnaissance of drainage wells in Florida; an interim report

USGS Publications Warehouse

Kimrey, Joel O.; Fayard, Larry D.

1982-01-01

Drainage wells are used to inject surface waters directly into an aquifer, or shallow ground waters directly into a deeper aquifer, primarily by gravity. Such wells in Florida may be grouped into two broad types: (1) Surface-water injection wells, and (2) interaquifer connector wells. Surface-water injection wells are commonly used to supplement drainage for urban areas in karst terranes of central and north Florida. Data are available for 25 wells in the Ocala, Live Oak, and Orlando areas that allow comparison of the quality of water samples from these Floridan aquifer drainage wells with allowable contaminant levels. Comparison indicates that maximum contaminant levels for turbidity, color, and iron, manganese, and lead concentrations are equaled or exceeded in some drainage-well samples, and relatively high counts for coliform bacteria are present in most wells. Interaquifer connector wells are used in the phosphate mining areas of Polk and Hillsborough Counties, to drain mining operations and recharge the Floridan aquifer. Water-quality data available from 13 connector wells indicate that samples from most of these wells exceed standards values for iron concentration and turbidity. One well yielded a highly mineralized water, and samples from 6 of the other 12 wells exceed standards values for gross alpha concentrations. (USGS)

Uncertainty considerations in calibration and validation of hydrologic and water quality models

USDA-ARS?s Scientific Manuscript database

Hydrologic and water quality models (HWQMs) are increasingly used to support decisions on the state of various environmental issues and policy directions on present and future scenarios, at scales varying from watershed to continental levels. Uncertainty associated with such models may impact the ca...

The Full-Scale Implementation of an Innovative Biological Ammonia Treatment Process

EPA Science Inventory

Across the United States, high levels of ammonia in drinking water sources can be found, including small communities like Palo, Iowa (approximate population of 1,026). Although ammonia in water does not pose a direct health concern, ammonia nitrification can cause a number of iss...

[Investigation on the phenomena of bacteria exceeding standards in rural pit water treated by ultrafiltration membrane].

PubMed

Yue, Yinling; Zhang, Lan; Ling, Bo

2011-11-01

To investigate the phenomenon of bacteria exceeding standards in rural pit water, which was intermittently operated by water pump equipped with ultrafiltration membrane, and to explore the solutions. Polyvinyl chloride (PVC) alloy capillary membranes combined with UV, disinfectant, one-way valve, water-seal, high water level-water tank and direct outlet were tested. The operation on water treatment was intermittent, simulating the ways of treating pit water in the rural. The combination modes of ultrafiltration membrane with UV, disinfectant and high water level-water tank are valid in solving the problem of high turbidity and microorganism of pit water stored in cellars, the quality of effluents was consistent with the requirements of the national standards. While the combination modes of ultrafiltration membrane with one-way valve or water-seal were less desirable, more bacteria in treated water than raw water were observed because of bacteria breeding on the membrane component. In order to avoid excessive bacteria in filtered pit water caused by intermittent operation, it is recommended that for the pit water in high water level water tanks, the ultrafiltration membranes should be cleaned with disinfectants on a regular basis. The effluent pit water from underground cellars should be disinfected with UV after ultrafiltration.

Best-estimate coupled RELAP/CONTAIN analysis of inadvertent BWR ADS valve opening transient

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

Feltus, M.A.; Muftuoglu, A.K.

1993-01-01

Noncondensible gases may become dissolved in boiling water reactor (BWR) water-level instrumentation during normal operations. Any dissolved noncondensible gases inside these water columns may come out of solution during rapid depressurization events and displace water from the reference leg piping, resulting in a false high level. Significant errors in water-level indication are not expected to occur until the reactor pressure vessel (RPV) pressure has dropped below [approximately]450 psig. These water level errors may cause a delay or failure in emergency core cooling system (ECCS) actuation. The RPV water level is monitored using the pressure of a water column having amore » varying height (reactor water level) that is compared to the pressure of a water column maintained at a constant height (reference level). The reference legs have small-diameter pipes with varying lengths that provide a constant head of water and are located outside the drywell. The amount of noncondensible gases dissolved in each reference leg is very dependent on the amount of leakage from the reference leg and its geometry and interaction of the reactor coolant system with the containment, i.e., torus or suppression pool, and reactor building. If a rapid depressurization causes an erroneously high water level, preventing automatic ECCS actuation, it becomes important to determine if there would be other adequate indications for operator response. In the postulated inadvertent opening of all seven automatic depressurization system (ADS) valves, the ECCS signal on high drywell pressure would be circumvented because the ADS valves discharge directly into the suppression pool. A best-estimate analysis of such an inadvertent opening of all ADS valves would have to consider the thermal-hydraulic coupling between the pool, drywell, reactor building, and RPV.« less

Documentation of a spreadsheet for time-series analysis and drawdown estimation

USGS Publications Warehouse

Halford, Keith J.

2006-01-01

Drawdowns during aquifer tests can be obscured by barometric pressure changes, earth tides, regional pumping, and recharge events in the water-level record. These stresses can create water-level fluctuations that should be removed from observed water levels prior to estimating drawdowns. Simple models have been developed for estimating unpumped water levels during aquifer tests that are referred to as synthetic water levels. These models sum multiple time series such as barometric pressure, tidal potential, and background water levels to simulate non-pumping water levels. The amplitude and phase of each time series are adjusted so that synthetic water levels match measured water levels during periods unaffected by an aquifer test. Differences between synthetic and measured water levels are minimized with a sum-of-squares objective function. Root-mean-square errors during fitting and prediction periods were compared multiple times at four geographically diverse sites. Prediction error equaled fitting error when fitting periods were greater than or equal to four times prediction periods. The proposed drawdown estimation approach has been implemented in a spreadsheet application. Measured time series are independent so that collection frequencies can differ and sampling times can be asynchronous. Time series can be viewed selectively and magnified easily. Fitting and prediction periods can be defined graphically or entered directly. Synthetic water levels for each observation well are created with earth tides, measured time series, moving averages of time series, and differences between measured and moving averages of time series. Selected series and fitting parameters for synthetic water levels are stored and drawdowns are estimated for prediction periods. Drawdowns can be viewed independently and adjusted visually if an anomaly skews initial drawdowns away from 0. The number of observations in a drawdown time series can be reduced by averaging across user-defined periods. Raw or reduced drawdown estimates can be copied from the spreadsheet application or written to tab-delimited ASCII files.

Estimated 2008 groundwater potentiometric surface and predevelopment to 2008 water-level change in the Santa Fe Group aquifer system in the Albuquerque area, central New Mexico

USGS Publications Warehouse

Falk, Sarah E.; Bexfield, Laura M.; Anderholm, Scott K.

2011-01-01

The water-supply requirements of the Albuquerque metropolitan area of central New Mexico have historically been met almost exclusively by groundwater withdrawal from the Santa Fe Group aquifer system. Previous studies have indicated that the large quantity of groundwater withdrawal relative to recharge has resulted in water-level declines in the aquifer system throughout the metropolitan area. Analysis of the magnitude and pattern of water-level change can help improve understanding of how the groundwater system responds to withdrawals and variations in the management of the water supply and can support water-management agencies' efforts to minimize future water-level declines and improve sustainability. This report, prepared by the U.S. Geological Survey in cooperation with the Albuquerque Bernalillo County Water Utility Authority, presents the estimated groundwater potentiometric surface during winter (from December to March) of the 2008 water year and the estimated changes in water levels between predevelopment and water year 2008 for the production zone of the Santa Fe Group aquifer system in the Albuquerque and surrounding metropolitan and military areas. Hydrographs from selected wells are included to provide details of historical water-level changes. In general, water-level measurements used for this report were measured in small-diameter observation wells screened over short intervals and were considered to best represent the potentiometric head in the production zone-the interval of the aquifer, about 300 feet below land surface to 1,100 feet or more below land surface, in which production wells generally are screened. Water-level measurements were collected by various local and Federal agencies. The 2008 water year potentiometric surface map was created in a geographic information system, and the change in water-level elevation from predevelopment to water year 2008 was calculated. The 2008 water-level contours indicate that the general direction of groundwater flow is from the Rio Grande towards clusters of production wells in the east, north, and west. Water-level changes from predevelopment to 2008 are variable across the area. Hydrographs from piezometers on the east side of the river generally indicate a trend of decline in the annual highest water level through most of the period of record. Hydrographs from piezometers in the valley near the river and on the west side of the river indicate spatial variability in water-level trends.

Towards real-time flood forecasting in hydraulics: merits of in situ discharge and water level data assimilation for the modeling of the Marne catchment in France

NASA Astrophysics Data System (ADS)

Ricci, S. M.; Habert, J.; Le Pape, E.; Piacentini, A.; Jonville, G.; Thual, O.; Zaoui, F.

2011-12-01

The present study describes the assimilation of river flow and water level observations and the resulting improvement in flood forecasting. The Kalman Filter algorithm was built on top of the one-dimensional hydraulic model, MASCARET, [1] which describes the Saint-Venant equations. The assimilation algorithm folds in two steps: the first one was based on the assumption that the upstream flow can be adjusted using a three-parameter correction; the second one consisted of directly correcting the hydraulic state. This procedure was previously applied on the Adour Maritime Catchment using water level observations [2]. On average, it was shown that the data assimilation procedure enables an improvement of 80% in the simulated water level over the reanalysis period, 60 % in the forecast water level at a one-hour lead time, and 25% at a twelve-hour lead time. The procedure was then applied on the Marne Catchment, which includes karstic tributaries, located East of the Paris basin, characterized by long flooding periods and strong sensitivity to local precipitations. The objective was to geographically extend and improve the existing model used by the flood forecasting service located in Chalons-en-Champagne. A hydrological study first enabled the specification of boundary conditions (upstream flow or lateral inflow), then the hydraulic model was calibrated using in situ discharge data (adjustment of Strickler coefficients or cross sectional geometry). The assimilation of water level data enabled the reduction of the uncertainty in the hydrological boundary conditions and led to significant improvement of the simulated water level in re-analysis and forecast modes. Still, because of errors in the Strickler coefficients or cross section geometry, the improvement of the simulated water level sometimes resulted in a degradation of discharge values. This problem was overcome by controlling the correction of the hydrological boundary conditions by directly assimilating discharge observations rather than water level observations. As this approach leads to a satisfying simulation of flood events in the Marne catchment in re-analysis and forecast mode, ongoing work aims at controlling Strickler coefficients through data assimilation procedures in order to simultaneously improve the water level and discharge state. [1] N. Goutal, F. Maurel: A finite volume solver for 1D shallow water equations applied to an actual river, Int. J. Numer. Meth. Fluids, 38(2), 1--19, 2002. [2] S. Ricci, A. Piacentini, O. Thual, E. Le Pape, G. Jonville, 2011: Correction of upstream flow and hydraulic state with data assimilation on the context of flood forecasting. Submitted to Hydrol. Earth Syst. Sci, In review.

A New Approach to Extract Forest Water Use Efficiency from Eddy Covariance Data

NASA Astrophysics Data System (ADS)

Scanlon, T. M.; Sulman, B. N.

2016-12-01

Determination of forest water use efficiency (WUE) from eddy covariance data typically involves the following steps: (a) estimating gross primary productivity (GPP) from direct measurements of net ecosystem exchange (NEE) by extrapolating nighttime ecosystem respiration (ER) to daytime conditions, and (b) assuming direct evaporation (E) is minimal several days after rainfall, meaning that direct measurements of evapotranspiration (ET) are identical to transpiration (T). Both of these steps could lead to errors in the estimation of forest WUE. Here, we present a theoretical approach for estimating WUE through the analysis of standard eddy covariance data, which circumvents these steps. Only five statistics are needed from the high-frequency time series to extract WUE: CO2 flux, water vapor flux, standard deviation in CO2 concentration, standard deviation in water vapor concentration, and the correlation coefficient between CO2 and water vapor concentration for each half-hour period. The approach is based on the assumption that stomatal fluxes (i.e. photosynthesis and transpiration) lead to perfectly negative correlations and non-stomatal fluxes (i.e. ecosystem respiration and direct evaporation) lead to perfectly positive correlations within the CO2 and water vapor high frequency time series measured above forest canopies. A mathematical framework is presented, followed by a proof of concept using eddy covariance data and leaf-level measurements of WUE.

Water Resources Investigations at Edwards Air Force Base since 1988

USGS Publications Warehouse

Sneed, Michelle; Nishikawa, Tracy; Martin, Peter

2006-01-01

Edwards Air Force Base (EAFB) in southern California (fig. 1) has relied on ground water to meet its water-supply needs. The extraction of ground water has led to two major problems that can directly affect the mission of EAFB: declining water levels (more than 120 ft since the 1920s) and land subsidence, a gradual downward movement of the land surface (more than 4 ft since the late 1920s). As water levels decline, this valuable resource becomes depleted, thus requiring mitigating measures. Land subsidence has caused cracked (fissured) runways and accelerated erosion on Rogers lakebed. In 1988, the U.S. Geological Survey (USGS), in cooperation with the U.S. Air Force, began investigations of the effects of declining water levels and land subsidence at EAFB and possible mitigation measures, such as the injection of imported surface water into the ground-water system. The cooperative investigations included data collection and analyses, numerical simulations of ground-water flow and land subsidence, and development of a preliminary simulation-optimization model. The results of these investigations indicate that the injection of imported water may help to control land subsidence; however, the potential ground-water-quality impacts are unknown.

Potentiometric Surfaces in the Springfield Plateau and Ozark Aquifers of Northwestern Arkansas, Southeastern Kansas, Southwestern Missouri, and Northeastern Oklahoma, 2006

USGS Publications Warehouse

Gillip, Jonathan A.; Czarnecki, John B.; Mugel, Douglas N.

2008-01-01

The Springfield Plateau and Ozark aquifers are important sources of ground water in the Ozark Plateaus aquifer system. Water from these aquifers is used for agricultural, domestic, industrial, and municipal water sources. Changing water use over time in these aquifers presents a need for updated potentiometric-surface maps of the Springfield Plateau and Ozark aquifers. The Springfield Plateau aquifer consists of water-bearing Mississippian-age limestone and chert. The Ozark aquifer consists of Late Cambrian to Middle Devonian age water-bearing rocks consisting of dolostone, limestone, and sandstone. Both aquifers are complex with areally varying lithologies, discrete hydrologic units, varying permeabilities, and secondary permeabilities related to fractures and karst features. During the spring of 2006, ground-water levels were measured in 285 wells. These data, and water levels from selected lakes, rivers, and springs, were used to create potentiometric-surface maps for the Springfield Plateau and Ozark aquifers. Linear kriging was used initially to construct the water-level contours on the maps; the contours were subsequently modified using hydrologic judgment. The potentiometric-surface maps presented in this report represent ground-water conditions during the spring of 2006. During the spring of 2006, the region received less than average rainfall. Dry conditions prior to the spring of 2006 could have contributed to the observed water levels as well. The potentiometric-surface map of the Springfield Plateau aquifer shows a maximum measured water-level altitude within the study area of about 1,450 feet at a spring in Barry County, Missouri, and a minimum measured water-level altitude of 579 feet at a well in Ottawa County, Oklahoma. Cones of depression occur in Dade, Lawrence and Newton Counties in Missouri and Delaware and Ottawa Counties in Oklahoma. These cones of depression are associated with private wells. Ground water in the Springfield Plateau aquifer generally flows to the west in the study area, and to surface features (lakes, rivers, and springs) particularly in the south and east of the study area where the Springfield Plateau aquifer is closest to land surface. The potentiometric-surface map of the Ozark aquifer indicates a maximum measured water-level altitude of 1,303 feet in the study area at a well in Washington County, Arkansas, and a minimum measured water-level altitude of 390 feet in Ottawa County, Oklahoma. The water in the Ozark aquifer generally flows to the northwest in the northern part of the study area and to the west in the remaining study area. Cones of depression occur in Barry, Barton, Cedar, Jasper, Lawrence, McDonald, Newton, and Vernon Counties in Missouri, Cherokee and Crawford Counties in Kansas, and Craig and Ottawa Counties in Oklahoma. These cones of depression are associated with municipal supply wells. The flow directions, based on both potentiometric-surface maps, generally agree with flow directions indicated by previous studies.

Water-quality conditions at selected landfills in Mecklenburg County, North Carolina, 1986-92

USGS Publications Warehouse

Ferrell, G.M.; Smith, D.G.

1995-01-01

Water-quality conditions at five municipal landfills in Mecklenburg County, North Carolina, were studied during 1986-92. Analytical results of water samples from monitoring wells and streams at and near the landfills were used to evaluate effects of leachate on surface and ground water. Ground-water levels at monitoring wells were used to determine directions of ground-water flow at the landfills. Data from previous studies were used for analysis of temporal trends in selected water-quality properties and chemical constituents. Effects of leachate, such as large biochemical- and chemical-oxygen demands, generally were evident in small streams originating within the landfills, whereas effects of leachate generally were not evident in most of the larger streams. In larger streams, surface-water quality upstream and downstream from most of the landfills was similar. However, the chemical quality of water in Irwin Creek appears to have been affected by the Statesville Road landfill. Concentrations of several constituents indicative of leachate were larger in samples collected from Irwin Creek downstream from the Statesville Road landfill than in samples collected from Irwin Creek upstream from the landfill. The effect of leachate on ground-water quality generally was largest in water from wells adjacent to waste-disposal cells. Concentrations of most constituents considered indicative of leachate generally were smaller with increasing distance from waste-disposal cells. Water samples from offsite wells generally indicated no effect or very small effects of leachate. Action levels designated by the Mecklenburg County Engineering Department and maximum contaminant levels established by the U.S. Environmental Protection Agency were exceeded in some samples from the landfills. Ground-water samples exceeded action levels and maximum contaminant levels more commonly than surface-water samples. Iron and manganese were the constituents that most commonly exceeded action levels in water samples from the landfills. Synthetic organic compounds were detected more commonly and in larger concentrations in ground-water samples than in surface-water samples. Concentrations of synthetic organic compounds detected in water samples from monitoring sites at the landfills generally were much less than maximum contaminant levels. However, concentrations of some chlorinated organic compounds exceeded maximum contaminant levels in samples from several monitoring wells at the Harrisburg Road and York Road landfills. Trend analysis indicated statistically significant temporal changes in concentrations of selected water-quality constituents and properties at some of the monitoring sites. Trends detected for the Holbrooks Road and Statesville Road landfills generally indicated an improvement in water quality and a decrease in effects of leachate at most monitoring sites at these landfills from 1979 to 1992. Water-quality trends detected for monitoring sites at the Harrisburg Road and York Road landfills, the largest landfills in the study, differed in magnitude and direction. Upward trends generally were detected for sites near recently closed waste-disposal cells, whereas downward trends generally were detected for sites near older waste-disposal cells. Temporal trends in water quality generally reflected changes in degradation processes associated with the aging of landfill wastes.

Development of an integrated methodology for the sustainable environmental and socio-economic management of river ecosystems.

PubMed

Koundouri, P; Ker Rault, P; Pergamalis, V; Skianis, V; Souliotis, I

2016-01-01

The development of the Water Framework Directive aimed to establish an integrated framework of water management at European level. This framework revolves around inland surface waters, transitional waters, coastal waters and ground waters. In the process of achieving the environment and ecological objectives set from the Directive, the role of economics is put in the core of the water management. An important feature of the Directive is the recovery of total economic cost of water services by all users. The total cost of water services can be disaggregated into environmental, financial and resource costs. Another important aspect of the directive is the identification of major drivers and pressures in each River Basin District. We describe a methodology that is aiming to achieve sustainable and environmental and socioeconomic management of freshwater ecosystem services. The Ecosystem Services Approach is in the core of the suggested methodology for the implementation of a more sustainable and efficient water management. This approach consists of the following three steps: (i) socio-economic characterization of the River Basin area, (ii) assessment of the current recovery of water use cost, and (iii) identification and suggestion of appropriate programs of measures for sustainable water management over space and time. This methodology is consistent with a) the economic principles adopted explicitly by the Water Framework Directive (WFD), b) the three-step WFD implementation approach adopted in the WATECO document, c) the Ecosystem Services Approach to valuing freshwater goods and services to humans. Furthermore, we analyze how the effects of multiple stressors and socio-economic development can be quantified in the context of freshwater resources management. We also attempt to estimate the value of four ecosystem services using the benefit transfer approach for the Anglian River Basin, which showed the significance of such services. Copyright © 2015. Published by Elsevier B.V.

Ecological impacts of winter water level drawdowns on lake littoral zones: A review

USGS Publications Warehouse

Roy, Allison

2017-01-01

Freshwater littoral zones harbor diverse ecological communities and serve numerous ecosystem functions that are controlled, in part, by natural water level fluctuations. However, human alteration of lake hydrologic regimes beyond natural fluctuations threaten littoral zone ecological integrity. One type of hydrologic alteration in lakes is winter water level drawdowns, which are frequently employed for hydropower, flood control, and macrophyte control, among other purposes. Here, we synthesize the abiotic and biotic responses to annual and novel winter water level drawdowns in littoral zones of lakes and reservoirs. The dewatering, freezing, and increased erosion of exposed lakebeds drive changes in the littoral zone. Shoreline-specific physicochemical conditions such as littoral slope and shoreline exposure further induce modifications. Loss of fine sediment decreases nutrient availability over time, but desiccation may promote a temporary nutrient pulse upon re-inundation. Annual winter drawdowns can decrease taxonomic richness of macrophytes and benthic invertebrates and shift assemblage composition to favor taxa with r-selected life history strategies and with functional traits resistant to direct and indirect drawdown effects. Fish assemblages, though less directly affected by winter drawdowns (except where there is critically low dissolved oxygen), experience negative effects via indirect pathways like decreased food resources and spawning habitat. We identify eight general research gaps to guide future research that could improve our understanding about the complex effects of winter drawdowns on littoral zone ecology.

Potentiometric surface map of the Magothy aquifer in southern Maryland, September, 2003

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Wheeler, Judith C.

2005-01-01

This report presents a map showing the potentiometric surface of the Magothy aquifer in the Magothy Formation of Upper Cretaceous age in Southern Maryland during September 2002. The map is based on water-level measurements in 79 wells. The highest measured water level was 83 feet above sea level near the northern boundary and outcrop area of the aquifer in the north-central part of Anne Arundel County. The potentiometric surface declined towards the south and east. Local gradients were directed toward the centers of two cones of depression that developed in response to pumping. These cones of depression were centered around well fields in the Waldorf area and at the Chalk Point power plant. Measured ground-water levels were as low as 81 feet below sea level in the Waldorf area and 75 feet below sea level at Chalk Point.

Potentiometric Surface of the Magothy Aquifer in Southern Maryland, September 2002

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Wheeler, Judith C.

2003-01-01

This report presents a map showing the potentiometric surface of the Magothy aquifer in the Magothy Formation of Upper Cretaceous age in Southern Maryland during September 2002. The map is based on water-level measurements in 79 wells. The highest measured water level was 83 feet above sea level near the northern boundary and outcrop area of the aquifer in the north-central part of Anne Arundel County. The potentiometric surface declined towards the south and east. Local gradients were directed toward the centers of two cones of depression that developed in response to pumping. These cones of depression were centered around well fields in the Waldorf area and at the Chalk Point power plant. Measured ground-water levels were as low as 81 feet below sea level in the Waldorf area and 75 feet below sea level at Chalk Point.

Effects of the proposed Prosperity Reservoir on ground water and water quality in lower Center Creek basin, Missouri

USGS Publications Warehouse

Berkas, Wayne R.; Barks, James H.

1980-01-01

Effects of the proposed Prosperity Reservoir on ground water and water quality in lower Center Creek basin depend partly on the effectiveness of Grove Creek as a hydrologic boundary between the reservoir site and the Oronogo-Duenweg mining belt. Results of two dye traces indicate that Grove Creek probably is not an effective boundary. Therefore, higher water levels near the reservoir may cause more ground water to move into the mining belt and cause a greater discharge of zinc-laden mine water into Center Creek.Ground-water-level measurements and seepage runs on Center Creek indicate a relationship between ground-water levels, mine-water discharge and seepage, and base flow in Center Creek. From March to October 1979, ground-water levels generally decreased from 5 to 20 feet at higher elevations (recharge areas) and from 1 to 3 feet near Center Creek (discharge area); total mine water discharged to the surface before entering Center Creek decreased from 5.4 to 2.2 cubic feet per second; mine-water seepage directly to Center Creek decreased from an estimated 1.9 to 1.1 cubic feet per second; and the discharge of Center Creek near Carterville decreased from 184 to 42 cubic feet per second.Fertilizer industry wastes discharged into Grove Creek resulted in significant increases of nitrogen and phosphorus in lower Center Creek.

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.

Hanford Site ground-water monitoring for 1993

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

Dresel, P.E.; Luttrell, S.P.; Evans, J.C.

This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1993 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiological and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1993 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporatedmore » to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1992 and June 1993. The greatest declines occurred in the 200-West Area. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal. Water levels remained nearly constant in the vicinity of B Pond, as a result of continued disposal to the pond. Water levels measured from wells in the unconfined aquifer north and east of the Columbia River indicate that the primary source of recharge is irrigation practices.« less

Human exposure assessment to antibiotic-resistant Escherichia coli through drinking water.

PubMed

O'Flaherty, E; Borrego, C M; Balcázar, J L; Cummins, E

2018-03-01

Antibiotic-resistant bacteria (ARB) are a potential threat to human health through drinking water with strong evidence of ARB presence in post treated tap water around the world. This study examines potential human exposure to antibiotic-resistant (AR) Escherichia coli (E. coli) through drinking water, the effect of different drinking water treatments on AR E. coli and the concentration of AR E. coli required in the source water for the EU Drinking Water Directive (DWD) (Council Directive 98/83/EC, 0CFU/100ml of E. coli in drinking water) to be exceeded. A number of scenarios were evaluated to examine different water treatment combinations and to reflect site specific conditions at a study site in Europe. A literature search was carried out to collate data on the effect of environmental conditions on AR E. coli, the effect of different water treatments on AR E. coli and typical human consumption levels of tap water. A human exposure assessment model was developed with probability distributions used to characterise uncertainty and variability in the input data. Overall results show the mean adult human exposure to AR E. coli from tap water consumption ranged between 3.44×10 -7 and 2.95×10 -1 cfu/day for the scenarios tested and varied depending on the water treatments used. The level of AR E. coli required in the source water pre-treatment to exceed the DWD varied between 1 and 5logcfu/ml, depending on the water treatments used. This can be used to set possible monitoring criteria in pre-treated water for potential ARB exposure in drinking water. Copyright © 2017 Elsevier B.V. All rights reserved.

What the Toadfish Ear Tells the Toadfish Brain About Sound.

PubMed

Edds-Walton, Peggy L

2016-01-01

Of the three, paired otolithic endorgans in the ear of teleost fishes, the saccule is the one most often demonstrated to have a major role in encoding frequencies of biologically relevant sounds. The toadfish saccule also encodes sound level and sound source direction in the phase-locked activity conveyed via auditory afferents to nuclei of the ipsilateral octaval column in the medulla. Although paired auditory receptors are present in teleost fishes, binaural processes were believed to be unimportant due to the speed of sound in water and the acoustic transparency of the tissues in water. In contrast, there are behavioral and anatomical data that support binaural processing in fishes. Studies in the toadfish combined anatomical tract-tracing and physiological recordings from identified sites along the ascending auditory pathway to document response characteristics at each level. Binaural computations in the medulla and midbrain sharpen the directional information provided by the saccule. Furthermore, physiological studies in the central nervous system indicated that encoding frequency, sound level, temporal pattern, and sound source direction are important components of what the toadfish ear tells the toadfish brain about sound.

[Investigation of the arsenic levels in ecosystem aspect in water type of endemic arsenicosis area in Datong City].

PubMed

Yun, Fen; Yang, Mimi; Ma, Caifeng; Miao, Yanling; Gao, Yi; Tian, Fengjie; Lü, Yi; Pei, Qiuling

2015-01-01

To investigate the arsenic levels in endemic arsenism in Datong City, Shanxi Province. A total of 85 inhabitants from one village in endemic arsenism area in Datong City, Shanxi Province were collected as research subjects. The People's Republic of China health industry standard for endemic arsenism was used to identify and diagnosis the patients. Daily drinking water and soil were collected and detected by atomic fluorescence spectrometry. The content of vegetables were detected by inductively coupled plasma mass spectrometry (ICP-MS). In the study, 85 samples were collected. Arsenic concentration in the daily drinking water were 14.41 - 90.34 μg/L, and the median value was 43.88 μg/L. The arsenic concentration of vegetables were 0.001 - 0.771 mg/kg, and 43.04% of samples, were higher than the maximal permissible limit of As in food. The results that the arsenic concentration of vegetables constant changes in the leaf vegetables > tubers > fruit vegetables. The health risk of intaking arsenic pollution in vegetables up to 71.77%. The arsenic levels in village of four directions were not exceeded the Chinese standards. Arsenic concentration in drinking water and vegetables are high in waterborn endemic arsenicosis area of Shanxi province. Arsenic in drinking water has been considered as a primary cause of arsenism, but direct intake of arsenic from vegetables can not be ignored.

Generalized potentiometric surface of aquifers of Pleistocene age, Southern Louisiana, 1980

USGS Publications Warehouse

Martin, Angel; Whiteman, Charles D.

1985-01-01

A map of potentiometric surface defines generalized water levels for 1980 in the Pleistocene aquifers of southern Louisiana. The map was prepared as part of the Western Gulf Coast Regional Aquifer-System Analysis study. The Pleistocene deposits in southern Louisiana consist of alternating beds of sand, gravel, silt, and clay deposited under fluvial, deltaic, and near-short marine conditions. The aquifers are mainly under artesian conditions and the regional flow direction is primarily southward. Areally definable cones of depression result from heavy pumpage in the Baton Rouge, Lake Charles, and New Orleans metropolitan areas and in the rice irrigation area of southwestern Louisiana. Where water levels differ vertically within the aquifer, the lowest water levels in the vertical section were used because these levels represented the thickest and most heavily pumped unit in the aquifer. The map represents regional water levels in the Pleistocene aquifers, and is not intended to show localized variations near pumping centers. (USGS)

Potentiometric Surface of the Upper Patapsco Aquifer in Southern Maryland, September 2007

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Staley, Andrew W.

2009-01-01

This report presents a map showing the potentiometric surface of the upper Patapsco aquifer in the Patapsco Formation of Early Cretaceous age in Southern Maryland during September 2007. The map is based on water-level measurements in 50 wells. The highest measured water level was 120 feet above sea level near the northern boundary and outcrop area of the aquifer in northern Anne Arundel County. From this area, the potentiometric surface declined to the south toward a well field in the Annapolis-Arnold area, and from all directions toward four cones of depression. These cones are located in the Waldorf-La Plata area, Chalk Point-Prince Frederick area, Swan Point subdivision in southern Charles County, and the Lexington Park-St. Inigoes area. The lowest measured ground-water level was 44 feet below sea level at Arnold, 106 feet below sea level south of Waldorf, 54 feet below sea level at Swan Point, 59 feet below sea level at Chalk Point, and 58 feet below sea level at Lexington Park.

Condensation nucleation light scattering detection with ion chromatography for direct determination of glyphosate and its metabolite in water.

PubMed

You, Jing; Koropchak, John A

2003-03-14

An ion chromatography-condensation nucleation light scattering detection (IC-CNLSD) method was successfully used to directly analyze glyphosate, a polar pesticide, and aminomethylphosaphonic acid, the major metabolite of glyphosate, in water without need of pre-treatment or derivatization. CNLSD gave a LOD of 53 ng/ml for glyphosate, which is much lower than the maximum contaminant level of 700 ng/ml for drinking water issued by the US Environmental Protection Agency. Spiked analytes in different matrixes were tested. A diluted commercial herbicide containing glyphosate was also evaluated. Compared to other reported methods, the IC-CNLSD method has no need of sample derivatization, pre-concentration, and mobile phase conductivity suppression. It is simple, fast and inexpensive. IC-CNLSD is an ideal direct detection technique for such pesticides without chromophores or fluorophores.

Tracking Seasonal and Diurnal Photosynthesis and Plant Water Status in Maize Using SIF, Eddy Covariance Fluxes, PAM Fluorescence and Gas Exchange

NASA Astrophysics Data System (ADS)

Chang, C.; Melkonian, J.; Riha, S. J.; Gu, L.; Sun, Y.

2017-12-01

Improving the sensitivity of methods for crop monitoring and yield forecasting is crucial as the frequency of extreme weather events increases. Conventional remote monitoring methods rely on greenness-based indices such as NDVI and EVI, which do not directly measure photosynthesis and are not sufficiently sensitive to rapid plant stress response. Solar-induced chlorophyll fluorescence (SIF) is a promising new technology that serves as a direct functional proxy of photosynthesis. We developed the first system utilizing dual QE Pro spectrometers to continuously measure the diurnal and seasonal cycle of SIF, and deployed the system in a corn field in upstate New York in 2017. To complement SIF, canopy-level measurements of carbon and water fluxes were also measured, along with concurrent leaf-level measurements of gas exchange and PAM fluorescence, midday water potential, leaf pigments, phenology, LAI, and soil moisture. We show that SIF is well correlated to GPP during the growing season and show that both are controlled by similar environmental conditions including PAR and water availability. We also describe diurnal changes in photosynthesis and plant water status and demonstrate the sensitivity of SIF to diurnal plant response.

Survival of human pathogenic bacteria in different types of natural mineral water.

PubMed

Serrano, Concepción; Romero, Margarita; Alou, Luis; Sevillano, David; Corvillo, Iluminada; Armijo, Francisco; Maraver, Francisco

2012-09-01

The aim of this study was to determine the survival of human pathogens (Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) in five natural mineral waters (NMWs) with different properties and mineralization levels. Five NMWs from four Spanish spas with different dry residue at 110 °C were used: A = 76,935 mg/L; B = 1,827 mg/L; C = 808.4 mg/L; D = 283.8 mg/L; and E = 170.4 mg/L. An initial inoculum of 1 × 10(6) colony forming units (cfu)/mL was used for survival studies. Distilled water, chlorinated tap water and Mueller-Hinton broth were used as controls. Colony counts in all different waters were lower than those achieved with Mueller-Hinton broth over all incubation periods. A direct effect between the bacterial survival and the level of mineralization water was observed. The NMW E with low mineralization level along with the radioactive properties showed the highest antibacterial activity among all NMWs.

Water level observations from Unmanned Aerial Vehicles (UAVs) for improving probabilistic estimations of interaction between rivers and groundwater

NASA Astrophysics Data System (ADS)

Bandini, Filippo; Butts, Michael; Vammen Jacobsen, Torsten; Bauer-Gottwein, Peter

2016-04-01

Integrated hydrological models are generally calibrated against observations of river discharge and piezometric head in groundwater aquifers. Integrated hydrological models are rarely calibrated against spatially distributed water level observations measured by either in-situ stations or spaceborne platforms. Indeed in-situ observations derived from ground-based stations are generally spaced too far apart to capture spatial patterns in the water surface. On the other hand spaceborne observations have limited spatial resolution. Additionally satellite observations have a temporal resolution which is not ideal for observing the temporal patterns of the hydrological variables during extreme events. UAVs (Unmanned Aerial Vehicles) offer several advantages: i) high spatial resolution; ii) tracking of the water body better than any satellite technology; iii) timing of the sampling merely depending on the operators. In this case study the Mølleåen river (Denmark) and its catchment have been simulated through an integrated hydrological model (MIKE 11-MIKE SHE). This model was initially calibrated against observations of river discharge retrieved by in-situ stations and against piezometric head of the aquifers. Subsequently the hydrological model has been calibrated against dense spatially distributed water level observations, which could potentially be retrieved by UAVs. Error characteristics of synthetic UAV water level observations were taken from a recent proof-of-concept study. Since the technology for ranging water level is under development, UAV synthetic water level observations were extracted from another model of the river with higher spatial resolution (cross sections located every 10 m). This model with high resolution is assumed to be absolute truth for the purpose of this work. The river model with the coarser resolution has been calibrated against the synthetic water level observations through Differential Evolution Adaptive Metropolis (DREAM) algorithm, an efficient global Markov Chain Monte Carlo (MCMC) in high-dimensional spaces. Calibration against water level has demonstrated a significant improvement of the estimation of the exchange flow between groundwater and river branch. Groundwater flux and direction are now better simulated. Reliability and sharpness of the probabilistic forecasts are assessed with the sharpness, the interval skill score (ISS) of the 95{%} confidence interval, and with the root mean square error (RMSE) of the maximum a posteriori probability (MAP). The binary outcome (either gaining or loosing stream) of the flow direction is assessed with Brier score (BS). After water level calibration the sharpness of the estimations is approximately doubled with respect to the model calibrated only against discharge, ISS has improved from 2.4-7to 7.8-8 m^3/s\\cdot m, RMSE from 9.2-8 to 2.4-8 m^3/s\\cdot m^and BS is halved from 0.58 to 0.25.

Irrigation management using an expert system, soil water potentials, and vegetative indices for spatial applications

USDA-ARS?s Scientific Manuscript database

Variable rate irrigation (VRI) systems are irrigation systems that are capable of applying different water depths both in the direction of travel and along the length of the irrigation system. However, when compared to traditional irrigation systems, VRI systems require a higher level of management...

Changes In Tree Species In Riparian Zones Of Urban Streams May Have Effects On Restoration And Storm Water Control Efforts

EPA Science Inventory

A riparian zone is the land and vegetation within and directly adjacent to surface water ecosystems, such as lakes and streams. The vegetation in riparian zones provides ecosystem services (such as reducing flooding and bank erosion and reducing levels of pollutants in streams) ...

Engineering Design and Operation Report: Biological ...

EPA Pesticide Factsheets

Many regions in the United States have excessive levels of ammonia in their drinking water sources (e.g., ground and surface waters) as a result of naturally occurring processes, agricultural and urban runoff, concentrated animal feeding operations, municipal wastewater treatment plants, and other sources. Ammonia is not regulated by the U.S. Environmental Protection Agency (EPA) as a contaminant. Based on a 2003 World Health Organization (WHO) assessment, ammonia levels in groundwater are typically below 0.2 milligrams per liter (mg/L), and do not pose a direct health concern at levels expected in drinking water (WHO 2003); however, they may pose a concern when nitrification of significant levels of ammonia from the source water occurs in the drinking water distribution system. Specifically, this nitrification, which is the conversion of the ammonia to nitrite and nitrate by bacteria, leads to water quality issues, such as potential corrosion problems, oxidant demand, taste and odor complaints, and elevated nitrite levels (Bremer et al.,2001; Fleming et al., 2005; Lee et al., 1980; Odell et al., 1996; Rittman & Snoeyink, 1984; Suffet et al., 1996). The EPA’s regulatory limits for nitrite and nitrate (at the entry point to the distribution system) are 0.1 and 10 mg N/L, respectively. Ammonia in water may also pose problems with water treatment effectiveness. For example, in source waters containing both ammonia and arsenic, the ammonia may negatively impact

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.

Monitoring Lake and Reservoir Level: Satellite Observations, Modeling and Prediction

NASA Astrophysics Data System (ADS)

Ricko, M.; Birkett, C. M.; Adler, R. F.; Carton, J.

2013-12-01

Satellite measurements of lake and reservoir water levels complement in situ observations by providing stage information for un-gauged basins and by filling data gaps in gauge records. However, different satellite radar altimeter-derived continental water level products may differ significantly owing to choice of satellites and data processing methods. To explore the impacts of these differences, a direct comparison between three different altimeter-based surface water level estimates (USDA/NASA GRLM, LEGOS and ESA-DMU) will be presented and products validated with lake level gauge time series for lakes and reservoirs of a variety of sizes and conditions. The availability of satellite-based rainfall (i.e., TRMM and GPCP) and satellite-based lake/reservoir levels offers exciting opportunities to estimate and monitor the hydrologic properties of the lake systems. Here, a simple water balance model is utilized to relate net freshwater flux on a catchment basin to lake/reservoir level. Focused on tropical lakes and reservoirs it allows a comparison of the flux to altimetric lake level estimates. The combined use of model, satellite-based rainfall, evaporation information and reanalysis products, can be used to output water-level hindcasts and seasonal future forecasts. Such a tool is fundamental for understanding present-day and future variations in lake/reservoir levels and enabling a better understand of climatic variations on inter-annual to inter-decadal time-scales. New model-derived water level estimates of lakes and reservoirs, on regional to global scales, would assist communities with interests in climate studies focusing on extreme events, such as floods and droughts, and be important for water resources management.

Incidence of enteroviruses in Mamala Bay, Hawaii using cell culture and direct polymerase chain reaction methodologies.

PubMed

Reynolds, K A; Roll, K; Fujioka, R S; Gerba, C P; Pepper, I L

1998-06-01

The consequence of point and nonpoint pollution sources, discharged into marine waters, on public recreational beaches in Mamala Bay, Hawaii was evaluated using virus cell culture and direct reverse transcriptase-polymerase chain reaction (RT-PCR). Twelve sites, nine marine, two freshwater (one stream and one canal), and one sewage, were assessed either quarterly or monthly for 1 year to detect the presence of human enteric viruses. Water samples were concentrated from initial volumes of 400 L to final volumes of 30 mL using Filterite electronegative cartridge filters and a modified beef extract elution procedure. Cell culture was applied using the Buffalo Green Monkey kidney cell line to analyze samples for enteroviruses. Positive samples were also evaluated by RT-PCR, using enterovirus-specific primers. Levels of RT-PCR inhibition varied with each concentrated sample. Resin column purification increased PCR detection sensitivity by at least one order of magnitude in a variety of sewage outfall and recreational marine water samples but not in the freshwater canal samples. Using cell culture, viable enteroviruses were found in 50 and 17% of all outfall and canal samples, respectively. Samples were positive at beaches 8% of the time. These data illustrate the potential public health hazard associated with recreational waters. Using direct PCR, viruses were detected at the outfall but were not found in any beach or canal samples, in part, owing to substances that inhibit PCR. Therefore, conventional cell culture is the most effective means of detecting low levels of infectious enteroviruses in environmental waters, whereas direct RT-PCR is rendered less effective by inhibitory compounds and low equivalent reaction volumes.

Report for Full-Scale Mulch Wall Treatment of Chlorinated Hydrocarbon-Impacted Groundwater

DTIC Science & Technology

2004-04-13

7.1 Direction of Groundwater Flow Through the Test Area Static water level measurements were taken every quarter after the installation of the...volatile organic compounds, alternate electron acceptors/byproducts and water quality parameters. Potentiometric surface maps showed the groundwater ... groundwater and surface water restrictions 10 Established clear zone (3000 ft by 3000 ft) Building 301 CEA Previously installed soil boring MW-19I 19

Analysis of Ground-Water Levels and Associated Trends in Yucca Flat, Nevada Test Site, Nye County, Nevada, 1951-2003

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

J.M. Fenelon

2005-10-05

Almost 4,000 water-level measurements in 216 wells in the Yucca Flat area from 1951 to 2003 were quality assured and analyzed. An interpretative database was developed that describes water-level conditions for each water level measured in Yucca Flat. Multiple attributes were assigned to each water-level measurement in the database to describe the hydrologic conditions at the time of measurement. General quality, temporal variability, regional significance, and hydrologic conditions are attributed for each water-level measurement. The database also includes narratives that discuss the water-level history of each well. Water levels in 34 wells were analyzed for variability and for statistically significantmore » trends. An attempt was made to identify the cause of many of the water-level fluctuations or trends. Potential causes include equilibration following well construction or development, pumping in the monitoring well, withdrawals from a nearby supply well, recharge from precipitation, earthquakes, underground nuclear tests, land subsidence, barometric pressure, and Earth tides. Some of the naturally occurring fluctuations in water levels may result from variations in recharge. The magnitude of the overall water-level change for these fluctuations generally is less than 2 feet. Long-term steady-state hydrographs for most of the wells open to carbonate rock have a very similar pattern. Carbonate-rock wells without the characteristic pattern are directly west of the Yucca and Topgallant faults in the southwestern part of Yucca Flat. Long-term steady-state hydrographs from wells open to volcanic tuffs or the Eleana confining unit have a distinctly different pattern from the general water-level pattern of the carbonate-rock aquifers. Anthropogenic water-level fluctuations were caused primarily by water withdrawals and nuclear testing. Nuclear tests affected water levels in many wells. Trends in these wells are attributed to test-cavity infilling or the effects of depressurization following nuclear testing. The magnitude of the overall water-level change for wells with anthropogenic trends can be large, ranging from several feet to hundreds of feet. Vertical water-level differences at 27 sites in Yucca Flat with multiple open intervals were compared. Large vertical differences were noted in volcanic rocks and in boreholes where water levels were affected by nuclear tests. Small vertical differences were noted within the carbonate-rock and valley-fill aquifers. Vertical hydraulic gradients generally are downward in volcanic rocks and from pre-Tertiary clastic rocks toward volcanic- or carbonate-rock units.« less

Analysis of ground-water levels and associated trends in Yucca Flat, Nevada Test Site, Nye County, Nevada, 1951-2003

USGS Publications Warehouse

Fenelon, Joseph M.

2005-01-01

Almost 4,000 water-level measurements in 216 wells in the Yucca Flat area from 1951 to 2003 were quality assured and analyzed. An interpretative database was developed that describes water-level conditions for each water level measured in Yucca Flat. Multiple attributes were assigned to each water-level measurement in the database to describe the hydrologic conditions at the time of measurement. General quality, temporal variability, regional significance, and hydrologic conditions are attributed for each water-level measurement. The database also includes narratives that discuss the water-level history of each well. Water levels in 34 wells were analyzed for variability and for statistically significant trends. An attempt was made to identify the cause of many of the water-level fluctuations or trends. Potential causes include equilibration following well construction or development, pumping in the monitoring well, withdrawals from a nearby supply well, recharge from precipitation, earthquakes, underground nuclear tests, land subsidence, barometric pressure, and Earth tides. Some of the naturally occurring fluctuations in water levels may result from variations in recharge. The magnitude of the overall water-level change for these fluctuations generally is less than 2 feet. Long-term steady-state hydrographs for most of the wells open to carbonate rock have a very similar pattern. Carbonate-rock wells without the characteristic pattern are directly west of the Yucca and Topgallant faults in the southwestern part of Yucca Flat. Long-term steady-state hydrographs from wells open to volcanic tuffs or the Eleana confining unit have a distinctly different pattern from the general water-level pattern of the carbonate-rock aquifers. Anthropogenic water-level fluctuations were caused primarily by water withdrawals and nuclear testing. Nuclear tests affected water levels in many wells. Trends in these wells are attributed to test-cavity infilling or the effects of depressurization following nuclear testing. The magnitude of the overall water-level change for wells with anthropogenic trends can be large, ranging from several feet to hundreds of feet. Vertical water-level differences at 27 sites in Yucca Flat with multiple open intervals were compared. Large vertical differences were noted in volcanic rocks and in boreholes where water levels were affected by nuclear tests. Small vertical differences were noted within the carbonate-rock and valley-fill aquifers. Vertical hydraulic gradients generally are downward in volcanic rocks and from pre-Tertiary clastic rocks toward volcanic- or carbonate-rock units.

Water ecosystem service function assessment based on eco-hydrological process in Luanhe Basin,China

NASA Astrophysics Data System (ADS)

Zhang, C.; Hao, C.; Qin, T.; Wang, G.; Weng, B.

2012-12-01

At present, ecological water are mainly occupied by a rapid development of social economic and population explosion, which seriously threat the ecological security and water security in watershed and regional scale. Due to the lack of a unified standard of measuring the benefit of water resource, social economic and ecosystem, the water allocation can't take place in social economic and ecosystem. The function which provided by water in terrestrial, aquatic and social economic system can be addressed through water ecosystem service function research, and it can guide the water allocation in water resource management. The function which provided by water in terrestrial, aquatic and social economic system can be addressed through water ecosystem service function research, and it can guide the water allocation in water resource management. Throughout the researches of water ecosystem service, a clear identification of the connection of water ecosystem service function has not been established, and eco-economic approach can't meet the practical requirement of water allocation. Based on "nature-artificiality" dual water cycle theory and eco-hydrological process, this paper proposes a connection and indicator system of water ecosystem service function. In approach, this paper establishes an integrated assessment approach through prototype observation technology, numerical simulation, physical simulation and modern geographic information technology. The core content is to couple an eco-hydrological model, which involves the key processes of distributed hydrological model (WEP), ecological model (CLM-DGVM), in terms of eco-hydrological process. This paper systematically evaluates the eco-hydrological process and evolution of Luanhe Basin in terms of precipitation, ET, runoff, groundwater, ecosystem's scale, form and distribution. According to the results of eco-hydrological process, this paper assesses the direct and derived service function. The result indicates that the general service function of 2010 has minor increase than 2007, however the general function of two years are in common level; Compare with different region, the upstream, middle stream and downstream indicates "worse", "common" and "good" level respectively. The first three derived functions are leisure, offer products and industrial water use. In the end, this paper investigates the evolution of water ecosystem service function under rising temperatures and elevated CO2 concentration scenarios in Luanhe Basin through eco-hydrological model. The results elaborate that the water ecosystem service functions would decline when temperature rising, and warming to 1.5 degree is the mutation point of sharp drop; Increased CO2 concentration scenario will improve the direct service function in the whole Basin; under the overlying scenario, different region shows different results, the direct service function will increased in upstream and middle stream, direct service function will drop in downstream. A comprehensive analysis indicates that the rising temperature is the major driven of water ecosystem service function in Luanhe Basin.

Effects of human management on black carbon sorption/desorption during a water transfer project: Recognizing impacts and identifying mitigation possibilities.

PubMed

Hao, Rong; Zhang, Jinliang; Wang, Peichao; Hu, Ronggui; Song, Yantun; Wu, Yupeng; Qiu, Guohong

2018-05-15

Water resources management is an important public concern. In this study, we examined the extent of sorption/desorption of trace pollutants to soil black carbon (BC) in the water level fluctuation zone (WLFZ) of the middle route of the South to North Water Transfer Project in China. In addition, we investigated the main management measures affecting these processes during the project. The results showed that the pseudo second-order model adequately describes the sorption/desorption of phenanthrene on the soil BC in the WLFZ. Water level fluctuation may indirectly influenced BC sorption/desorption by altering water chemistry. Water level residence time had negative effects on BC sorption in short-term experiments (days to months), but the impact gradually diminished with increased residence time. The results suggested that long-term field monitoring of water chemistry is urgent. During the initial period of water transfer, delaying the water supplies as drinking water source or directly irrigating crops could mitigate the adverse impacts. Future research should focus on the water-soluble products of BC degradation. The findings of this study should be useful in improving sustainable management of water resources for water transfer projects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of the effects of precipitation on ground-water levels from wells in selected alluvial aquifers in Utah and Arizona, 1936-2005

USGS Publications Warehouse

Gardner, Philip M.; Heilweil, Victor M.

2009-01-01

Increased withdrawals from alluvial aquifers of the southwestern United States during the last half-century have intensified the effects of drought on ground-water levels in valleys where withdrawal for irrigation is greatest. Furthermore, during wet periods, reduced withdrawals coupled with increased natural recharge cause rising ground-water levels. In order to manage water resources more effectively, analysis of ground-water levels under the influence of natural and anthropogenic stresses is useful. This report evaluates the effects of precipitation patterns on ground-water levels in areas of Utah and Arizona that have experienced different amounts of ground-water withdrawal. This includes a comparison of water-level records from basins that are hydrogeologically and climatologically similar but have contrasting levels of ground-water development. Hydrologic data, including records of ground-water levels, basin-wide annual ground-water withdrawals, and precipitation were examined from two basins in Utah (Milford and central Sevier) and three in Arizona (Aravaipa Canyon, Willcox, and Douglas). Most water-level records examined in this study from basins experiencing substantial ground-water development (Milford, Douglas, and Willcox) showed strong trends of declining water levels. Other water-level records, generally from the less-developed basins (central Sevier and Aravaipa Canyon) exhibited trends of increasing water levels. These trends are likely the result of accumulating infiltration of unconsumed irrigation water. Water-level records that had significant trends were detrended by subtraction of a low-order polynomial in an attempt to eliminate the variation in the water-level records that resulted from ground-water withdrawal or the application of water for irrigation. After detrending, water-level residuals were correlated with 2- to 10-year moving averages of annual precipitation from representative stations for the individual basins. The water-level residual time series for each well was matched with the 2- to 10-year moving average of annual precipitation with which it was best correlated and the results were compared across basins and hydrologic settings. Analysis of water-level residuals and moving averages of annual precipitation indicate that ground-water levels in the Utah basins respond more slowly to precipitation patterns than those from the Arizona basins. This is attributed to the dominant mechanism of recharge that most directly influences the respective valley aquifers. Substantial recharge in the Utah basins likely originates as infiltrating snowmelt in the mountain block far from the valley aquifer, whereas mountain-front recharge and streambed infiltration of runoff are the dominant recharge mechanisms operating in the Arizona basins. It was determined that the fraction of water-level variation caused by local precipitation patterns becomes more difficult to resolve with increasing effects of ground-water pumping, especially from incomplete records. As the demand for ground water increases in the southwestern United States, long-term records of ground-water levels have the potential to provide valuable information about the precipitation-driven variation in water levels, which has implications to water management related to water availability.

Inventory of ground-water resources in the Kabul Basin, Afghanistan

USGS Publications Warehouse

Broshears, Robert E.; Akbari, M. Amin; Chornack, Michael P.; Mueller, David K.; Ruddy, Barbara C.

2005-01-01

In 2004, the U.S. Geological Survey began working with engineers at the Afghanistan Geological Survey to provide hydrologic training and equipment and to apply these tools to build an inventory of water wells in the Kabul Basin of Afghanistan. An inventory of 148 wells now includes information on well location, depth, and access. Water-level and water-quality measurements have been made at most of these wells. A water-level elevation map has been constructed, and general directions of ground-water flow have been defined. Ground-water flow in the Kabul Basin is primarily through saturated alluvium and other basin-fill sediments. The water-table surface generally mirrors topography, and ground water generally flows in the directions of surface-water discharge. The quality of ground water in the Kabul Basin varies widely. In some areas, ground-water quality is excellent, with low concentrations of dissolved solids and no problematic constituents. In other areas, however, high concentrations of dissolved solids and the presence of some constituents at concentrations deemed harmful to humans and crops render untreated ground water marginal or unsuitable for public supply and/or agricultural use. Of particular concern are elevated concentrations of nitrate, boron, and dissolved solids, and an indication of fecal pollution in some parts of the basin. As Afghanistan emerges from years of conflict, as institutional capacities rejuvenate and grow, and as the need for wise water-management decisions continues, adequate data and a fuller understanding of the ground-water resource in the Kabul Basin will be imperative. The work described in this report represents only a modest beginning in what will be a long-term data-collection and interpretive effort.

Concentration of Uranium Radioisotopes in Albanian Drinking Waters Measured by Alpha Spectrometry

NASA Astrophysics Data System (ADS)

Bylyku, Elida; Cfarku, Florinda; Deda, Antoneta; Bode, Kozeta; Fishka, Kujtim

2010-01-01

Uranium is a radioactive material that is frequently found in rocks and soil. When uranium decays, it changes into different elements that are also radioactive, including radon, a gas that is known to cause a lung cancer. The main concern with uranium in drinking water is harm to the kidneys. Public water systems are required to keep uranium levels at or below 500 mBq per liter to protect against kidney damage. Such an interest is needed due to safety, regulatory compliance and disposal issue for uranium in the environment since uranium is included as an obligatory controlled radionuclide in the European Legislation (Directive 98/83 CE of Council of 03.11.1998). The aim of this work is to measure the levels of uranium in drinking and drilled well waters in Albania. At first each sample was measured for total Alpha and total Beta activity. The samples with the highest levels of total alpha activity were chosen for the determination of uranium radioisotopes by alpha spectrometry. A radiochemical procedure using extraction with TBP (Tri-Butyl-Phosphate) is used in the presence of U232 as a yield tracer. Thin sources for alpha spectrometry are prepared by electrodepositing on to stainless steel discs. The results of the U238 activity measured in the different samples, depending from their geological origin range between 0.55-13.87 mBq/l. All samples measured results under the European Directive limits for U238 (5-500 mBq/1), Dose Coefficients according to Directive 96/29 EURATOM.

How trust and emotions influence policy acceptance: The case of the Irish water charges.

PubMed

Rodriguez-Sanchez, Carla; Schuitema, Geertje; Claudy, Marius; Sancho-Esper, Franco

2018-02-01

The introduction of new policies can evoke strong emotional reactions by the public. Yet, social-psychological research has paid little attention to affective determinants of individual-level policy acceptance. Building on recent theoretical and empirical advances around emotions and decision-making, we evaluate how people's trust and integral emotions function as important antecedents of cognitive evaluations, and subsequent acceptance of policies. We test our hypotheses within a sample of Irish citizens (n = 505), who were subject to the introduction of water charges in 2015. In line with our hypotheses, results show that general trust in government shapes emotions regarding water charges, which in turn, directly and via expected costs and benefits, influence policy acceptance. Additionally, we find that negative emotions have a larger direct effect on policy acceptance than positive emotions. Specifically, 'anger' was the main negative emotion that influenced the acceptance of the water charge. We conclude by discussing directions for future research around emotions and policy acceptance. © 2018 The British Psychological Society.

Can frequent precipitation moderate drought impact on peatmoss carbon uptake in northern peatlands?

NASA Astrophysics Data System (ADS)

Nijp, Jelmer; Limpens, Juul; Metselaar, Klaas; van der Zee, Sjoerd; Berendse, Frank; Robroek, Bjorn

2014-05-01

Northern peatlands represent one of the largest global carbon stores that can potentially be released by water table drawdown during extreme summer droughts. Small precipitation events may moderate negative impacts of deep water levels on carbon uptake by sustaining photosynthesis of peatmoss (Sphagnum spp.), the key species in these ecosystems. We experimentally assessed the importance of the temporal distribution of precipitation for Sphagnum water supply and carbon uptake during a stepwise decrease in water levels in a growth chamber. CO2 exchange and the water balance were measured for intact cores of three peatmoss species representative of three contrasting habitats in northern peatlands (Sphagnum fuscum, S. balticum and S. majus). For shallow water levels, capillary rise was the most important source of water for peatmoss photosynthesis and precipitation did not promote carbon uptake irrespective of peatmoss species. For deep water levels, however, precipitation dominated over capillary rise and moderated adverse effects of drought on carbon uptake by peat mosses. The ability to use the transient water supply by precipitation was species-specific: carbon uptake of S. fuscum increased linearly with precipitation frequency for deep water levels, whereas S. balticum and S. majus showed depressed carbon uptake at intermediate precipitation frequencies. Our results highlight the importance of precipitation for carbon uptake by peatmosses. The potential of precipitation to moderate drought impact, however, is species specific and depends on the temporal distribution of precipitation and water level. These results also suggest that modelling approaches in which water level depth is used as the only state variable determining water availability in the living moss layer and (in)directly linked to Sphagnum carbon uptake may have serious drawbacks. The predictive power of peatland ecosystem models may be reduced when deep water levels prevail, as precipitation frequency and quantity are likely the main variables controlling carbon uptake.

Groundwater Recharge Assessment in a Remote Region of Colombia Through Citizen Science

NASA Astrophysics Data System (ADS)

Gomez, A. M.; Wise, E.; Riveros-Iregui, D.

2017-12-01

Understanding water dynamic and storage is essential for decision making in hydrology issues. In remote groundwater-dependent regions affected by population displacement and land over exploitation, especially in developing economies, limited data hinders the production of information necessary to formulate and implement effective water management plans. The community science research approach, which seeks to solve scientific questions with the participation of the community at various levels, represents an opportunity in these regions. We present results of a citizen science project developed to improve the conceptualization of groundwater flow path and to estimate the monthly direct recharge to the shallow aquifer in a remote rural region, the Man River watershed, located in one of the last foothills between the Western and Central Andes cordillera in Colombia. This project was conducted by: i) implementing a water level monitoring network aided by the community to collect weekly data from 2007 to 2010; ii) comparing the precipitation data and water table time series to identify the response of the shallow aquifer to the wet season; iii) conceptualizing specific groundwater-surface interactions through water table spatial analysis; and iv) estimating direct groundwater recharge using the Water Table Fluctuation method. Water quality test results were shared with the local community. Results show that groundwater interacts with the main tributaries to the Man River. Two scenarios were identified related to water table temporal behavior: (1) the water table rises during the transition from the dry to the wet season (between March and April), and (2) it increases one month after this transition. In general, groundwater levels descend in November, which is the end of the wet season. The work with the community provided useful insights for interpreting the collected data and allowed for information exchange concerning the groundwater quality and methods for improving the sanitary conditions of the dug wells. This project represents a valuable strategy for adding information to the hydrogeological conceptual model at low cost. It also provides opportunities for the implementation of a more informed water management plan while improving water quality and accessibility at the domestic household level.

Evaluation of hydrologic data collected at the North Penn Area 12 Superfund Site, Montgomery County, Pennsylvania

USGS Publications Warehouse

Senior, Lisa A.; Grazul, Kevin E.; Wood, Charles R.

1998-01-01

The North Penn Area 12 Superfund Site is underlain by the Lockatong Formation, which consists of interbedded gray to black siltstone and shale. The beds of the Lockatong Formation strike northeast and dip about 10d to 20d to the northwest in the vicinity of the site. Ground water moves through fractures that are nearly vertical and horizontal in the shale and siltstone. Permeability and storage are very low. Borehole-geophysical logs were obtained from eight wells to determine the location of fractures, water-producing and water-receiving intervals, and intervals of borehole flow. The logs also were used to quantify fluid movement in the borehole, to characterize the lithology, and to obtain data on well construction. The logs indicate fractures at depths less than 100 feet are more frequent and generally are more productive than fractures at depths greater than 100 feet. The fluid resistivity of water in shallow intervals usually was greater than that in deeper intervals. The rate and direction of fluid movement under nonpumping conditions differs in the boreholes logged. In the northwest part of the site, no vertical flow was detected in three wells and very small amounts of flow were measured in two wells. In the southwest part of the site, downward flow was measured in two wells. Aquifer-isolation tests in three wells provided information on hydraulic heads and specific capacities in discrete vertical intervals and allowed collection of water samples form discrete water-bearing intervals. Natural annual fluctuations of water levels in 11 wells ranged form 11.4 to 28.3 feet. Seven of the 11 wells gave very similar water-level hydrographs. The four southernmost wells on the site show rises in water levels after precipitation much sooner than the other seven wells. Two other wells show daily fluctuations caused by pumping. A potentiometric-surface map of the site and vicinity was prepared from water-level measurements made in late July 1995. The map can be used to determine the approximate direction of ground-water flow.

Mapping the transition from catalyst-pool to bamboo-like growth-mechanism in vertically-aligned free-standing films of carbon nanotubes filled with Fe3C: The key role of water

NASA Astrophysics Data System (ADS)

Boi, Filippo S.; Wang, Shanling; He, Yi

2016-08-01

The control of carbon nanotube growth has challenged researchers for more than a decade due to the complex parameters-control necessary in the commonly used CVD approaches. Here we show that a direct transition from the catalyst-pool growth mechanism characterized by graphene-caps in the direction of growth to a bamboo-shaped mechanism characterized by the repetition of periodic elongated graphitic compartments is present when controlled quantities of water are added to ferrocene/dichlorobenzene. Our results suggest that water-addition allows enhancing the level of stress accumulated under the graphitic nanotubes-cap.

Heating the Ice-Covered Lakes of the McMurdo Dry Valleys, Antarctica - Decadal Trends in Heat Content, Ice Thickness, and Heat Exchange

NASA Astrophysics Data System (ADS)

Gooseff, M. N.; Priscu, J. C.; Doran, P. T.; Chiuchiolo, A.; Obryk, M.

2014-12-01

Lakes integrate landscape processes and climate conditions. Most of the permanently ice-covered lakes in the McMurdo Dry Valleys, Antarctica are closed basin, receiving glacial melt water from streams for 10-12 weeks per year. Lake levels rise during the austral summer are balanced by sublimation of ice covers (year-round) and evaporation of open water moats (summer only). Vertical profiles of water temperature have been measured in three lakes in Taylor Valley since 1988. Up to 2002, lake levels were dropping, ice covers were thickening, and total heat contents were decreasing. These lakes have been gaining heat since the mid-2000s, at rates as high as 19.5x1014 cal/decade). Since 2002, lake levels have risen substantially (as much as 2.5 m), and ice covers have thinned (1.5 m on average). Analyses of lake ice thickness, meteorological conditions, and stream water heat loads indicate that the main source of heat to these lakes is from latent heat released when ice-covers form during the winter. An aditional source of heat to the lakes is water inflows from streams and direct glacieal melt. Mean lake temperatures in the past few years have stabilized or cooled, despite increases in lake level and total heat content, suggesting increased direct inflow of meltwater from glaciers. These results indicate that McMurdo Dry Valley lakes are sensitive indicators of climate processes in this polar desert landscape and demonstrate the importance of long-term data sets when addressing the effects of climate on ecosystem 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.

Use of Tritium and Helium to Define Groundwater Flow Conditions in a Coastal Aquifer Influenced by Seawater Intrusion: Everglades National Park

NASA Astrophysics Data System (ADS)

Price, R. M.; Top, Z.; Happell, J. D.; Swart, P. K.

2002-05-01

The concentrations of tritium (3H) and helium isotopes (3He, 4He) were used as tracers of groundwater flow in Everglades National Park, South Florida (USA). Both fresh and brackish groundwaters were collected from 47 wells completed at depths ranging from 2 m to 73 m within the Surficial Aquifer System (SAS). Ages as determined by 3H/3He techniques indicate that groundwater within the upper 28 m originated after the nuclear era (within the last 42 yr) and below 28 m before then with evidence of some mixing at the interface. Inter-annual variation of the 3H/3He ages within the upper 28 m was significant throughout the three year investigation, suggesting varying hydrologic conditions. The age of the shallow groundwater in the southern regions of ENP (Rocky Glades and Taylor Slough) tended to be younger following times of high water level when the dominant direction of groundwater flow water was to the southeast. In the same region, significantly older groundwater was observed following times of low water levels and a shift in the groundwater flow direction toward the southwest. Near the canals, the reverse occurred with the ages of shallow groundwater tending to be younger following times of low water levels, suggesting a greater influence of recharge water from the canals to the surrounding aquifer. Although water levels and the direction of hydrologic gradients vary greatly within a 3-month time period, the average age of the shallow (<28 m) fresh groundwaters was 17 +/- 9 years. In the region of Taylor Slough Bridge, younger groundwater was consistently detected below older groundwater in the Biscayne Aquifer suggesting a preferential flow path to the deeper formation. An increase in 4He with depth suggests that radiogenic 4He produced in the underlying Hawthorn Group is dispersed into the SAS. Higher Δ 4He values in brackish groundwaters compared to fresh waters from similar depths indicate an enhanced vertical transport of 4He in the seawater mixing zone. Seawater intrudes at distances of 6 to 28 km at shallow depths (<28 m) in the SAS along the entire coastline of ENP and further inland at depths up to 68 m thereby preventing the direct discharge of fresh groundwater from the SAS into downgradient marine systems. Instead, brackish to saline groundwater is expected to discharge to the overlying surface water of the Everglades and possibly along the coastlines of Florida Bay and the Gulf of Mexico over an approximately 6 to 28 km wide strip that parallels the coastline.

Excretion of arsenic (As) in urine of children, 7-11 years, exposed to elevated levels of As in the city water supply in Hermosillo, Sonora, México.

PubMed

Wyatt, C J; Lopez Quiroga, V; Olivas Acosta, R T; Olivia Méndez, R

1998-07-01

Arsenic (As) is a common element in the environment with many industrial uses, but it also can be a contaminant in drinking water and present serious health concerns. Earlier studies on the quality of drinking water in the city of Hermosillo, Sonora, México, showed high levels of As (> 0.05 ppm) in water from wells located in the northern part of the city. Additionally a high positive correlation between the levels of Fluoride (F) and As in the same wells was found. Therefore, the objective of this study was to determine the excretion of As in children, 7-11 years of age, that had been exposed to elevated levels of As in their drinking water. Twenty-four-hour urine samples and a water sample taken directly in the home were collected from school age children living in two different areas with known high levels of As in their drinking water. A control group with normal levels of As in their water was also included. As was determined by an atomic absorption-hydride generator, verified with the use of NBS certified standards (SRM 1643a and SRM 2670). None of the water samples exceeded the limit established for drinking water; however, there was a significant difference between the intake of As and the As in drinking water among the three areas of the study. Average As in water was 0.009 +/- 0.002 and 0.030 +/- 0.011 micrograms/ml between the control and high areas. Intake (in micrograms/day) was 15 +/- 3 and 54 +/- 18. In the group consuming water with high levels of As, 65% of the children exceeded the recommended dose of < 1 micrograms/kg/day (EPA, 1988). Several children in this study also had high levels of As in their urine. Even though As levels in the drinking water are within the norms, it appears that children exposed to high levels of As in their drinking water may have a health risk.

Trends in the components of extreme water levels signal a rotation of winds in strong storms in the eastern Baltic Sea

NASA Astrophysics Data System (ADS)

Pindsoo, Katri; Soomere, Tarmo

2016-04-01

The water level time series and particularly temporal variations in water level extremes usually do not follow any simple rule. Still, the analysis of linear trends in extreme values of surge levels is a convenient tool to obtain a first approximation of the future projections of the risks associated with coastal floodings. We demonstrate how this tool can be used to extract essential information about concealed changes in the forcing factors of seas and oceans. A specific feature of the Baltic Sea is that sequences of even moderate storms may raise the average sea level by almost 1 m for a few weeks. Such events occur once in a few years. They substantially contribute to the extreme water levels in the eastern Baltic Sea: the most devastating coastal floodings occur when a strong storm from unfortunate direction arrives during such an event. We focus on the separation of subtidal (weekly-scale) processes from those which are caused by a single storm and on establishing how much these two kinds of events have contributed to the increase in the extreme water levels in the eastern Baltic Sea. The analysis relies on numerically reconstructed sea levels produced by the RCO (Rossby Center, Swedish Meteorological and Hydrological Institute) ocean model for 1961-2005. The reaction of sea surface to single storm events is isolated from the local water level time series using a running average over a fixed interval. The distribution of average water levels has an almost Gaussian shape for averaging lengths from a few days to a few months. The residual (total water level minus the average) can be interpreted as a proxy of the local storm surges. Interestingly, for the 8-day average this residual almost exactly follows the exponential distribution. Therefore, for this averaging length the heights of local storm surges reflect an underlying Poisson process. This feature is universal for the entire eastern Baltic Sea coast. The slopes of the exponential distribution for low and high water levels are different, vary markedly along the coast and provide a useful quantification of the vulnerability of single coastal segments with respect to coastal flooding. The formal linear trends in the extreme values of these water level components exhibit radically different spatial variations. The slopes of the trends in the weekly average are almost constant (~4 cm/decade for 8-day running average) along the entire eastern Baltic Sea coast. This first of all indicates that the duration of storm sequences has increased. The trends for maxima of local storm surge heights represent almost the entire spatial variability in the water level extremes. Their slopes are almost zero at the open Baltic Proper coasts of the Western Estonian archipelago. Therefore, an increase in wind speed in strong storms is unlikely in this area. In contrast, the slopes in question reach 5-7 cm/decade in the eastern Gulf of Finland and Gulf of Riga. This feature suggests that wind direction in strongest storms may have rotated in the northern Baltic Sea.

Recharge contribution to the Guarani Aquifer System estimated from the water balance method in a representative watershed.

PubMed

Wendland, Edson; Gomes, Luis H; Troeger, Uwe

2015-01-01

The contribution of recharge to regional groundwater flow systems is essential information required to establish sustainable water resources management. The objective of this work was to determine the groundwater outflow in the Ribeirão da Onça Basin using a water balance model of the saturated soil zone. The basin is located in the outcrop region of the Guarani Aquifer System (GAS). The water balance method involved the determination of direct recharge values, groundwater storage variation and base flow. The direct recharge was determined by the water table fluctuation method (WTF). The base flow was calculated by the hydrograph separation method, which was generated by a rain-flow model supported by biweekly streamflow measurements in the control section. Undisturbed soil samples were collected at depths corresponding to the variation zone of the groundwater level to determine the specific yield of the soil (drainable porosity). Water balances were performed in the saturated zone for the hydrological years from February 2004 to January 2007. The direct recharge ranged from 14.0% to 38.0%, and groundwater outflow from 0.4% to 2.4% of the respective rainfall during the same period.

Use of Unmanned Aerial Vehicles for Improving Farm Scale Agricultural Water Management in Agriculture at a Farm Scale. A case study for field crops in the California's Central Valley

NASA Astrophysics Data System (ADS)

Medellin-Azuara, J.; Morande, J. A.; Jin, Y.; Chen, Y.; Paw U, K. T.; Viers, J. H.

2016-12-01

Traditional methods for estimating consumptive water use as evapotranspiration (ET) for agriculture in areas with water limitations such as California have always been a challenge for farmers, water managers, researchers and government agencies. Direct measurement of evapotranspiration (ET) and crop water stress in agriculture can be a cumbersome and costly task. Furthermore, spatial variability of applied water and irrigation and stress level in crops, due to inherent heterogeneity in soil conditions, topography, management practices, and lack of uniformity in water applications may affect estimates water use efficiency and water balances. This situation difficult long-term management of agroecosystems. This paper presents a case study for various areas in California's Central Valley using Unmanned Aerial Vehicles (UAVs) for a late portion of the 2016 irrigation season These estimates are compared those obtained by direct measurement (from previously deployed stations), and energy balance approaches with remotely sensed data in a selection of field crop parcels. This research improves information on water use and site conditions in agriculture by enhancing remote sensing-based estimations through the use of higher resolution multi-spectral and thermal imagery captured by UAV. We assess whether more frequent information at higher spatial resolution from UAVs can improve estimations of overall ET through energy balance and imagery. Stress levels and ET are characterized spatially to examine irrigation practices and their performance to improve water use in the agroecosystem. Ground based data such as air and crop temperature and stem water potential is collected to validate UAV aerial measurements. Preliminary results show the potential of UAV technology to improve timing, resolution and accuracy in the ET estimation and assessment of crop stress at a farm scales. Side to side comparison with ground level stations employing surface renewal, eddy covariance and energy balance provides a testbed to improve understanding of consumptive use and crop water management in water scarce irrigated agriculture regions. Keywords. California Central Valley, Agricultural Water Use, Remote Sensing, Energy Balance, Evapotranspiration, Water management,

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.

Imported water risk: the case of the UK

NASA Astrophysics Data System (ADS)

Hoekstra, Arjen Y.; Mekonnen, Mesfin M.

2016-05-01

While the water dependency of water-scarce nations is well understood, this is not the case for countries in temperate and humid climates, even though various studies have shown that many of such countries strongly rely on the import of water-intensive commodities from elsewhere. In this study we introduce a method to evaluate the sustainability and efficiency of the external water footprint (WF) of a country, with the UK as an example. We trace, quantify and map the UK’s direct and indirect water needs and assess the ‘imported water risk’ by evaluating the sustainability of the water consumption in the source regions. In addition, we assess the efficiency of the water consumption in source areas in order to identify the room for water savings. We find that half of the UK’s global blue WF—the direct and indirect consumption of ground- and surface water resources behind all commodities consumed in the UK—is located in places where the blue WF exceeds the maximum sustainable blue WF. About 55% of the unsustainable part of the UK’s blue WF is located in six countries: Spain (14%), USA (11%), Pakistan (10%), India (7%), Iran (6%), and South Africa (6%). Our analysis further shows that about half of the global consumptive WF of the UK’s direct and indirect crop consumption is inefficient, which means that consumptive WFs exceed specified WF benchmark levels. About 37% of the inefficient part of the UK’s consumptive WF is located in six countries: Indonesia (7%), Ghana (7%), India (7%), Brazil (6%), Spain (5%), and Argentina (5%). In some source countries, like Pakistan, Iran, Spain, USA and Egypt, unsustainable and inefficient blue water consumption coincide. We find that, by lowering overall consumptive WFs to benchmark levels, the global blue WF of UK crop consumption could be reduced by 19%. We discuss four strategies to mitigate imported water risk: become more self-sufficient in food; diversify the import of water-intensive commodities, favouring the sourcing from water-abundant regions; reconsider the import of water-intensive commodities from the regions that are most severely water stressed altogether; and collaborate internationally with source countries with unsustainable water use where opportunities exist to increase water productivity.

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.

Ground-water hydrology of the upper Sevier River Basin, south-central Utah, and simulation of ground-water flow in the valley-fill in Panguitch Valley.

USGS Publications Warehouse

Thiros, Susan A.; Brothers, William C.

1993-01-01

The ground-water hydrology of the upper Sevier River basin, primarily of the unconsolidated valley-fill aquifers, was studied from 1988 to 1989. Recharge to the valley-fill aquifers is mostly by seepage from surface-water sources. Changes in soil-moisture content am water levels were measured in Panguitch Valley both at a flood-irrigated and at a sprinkler-irrigated alfalfa field to quantify seepage from unconsumed irrigation water. Lag time between irrigation and water-level response decreased from 6 to 2 days in the flood-irrigated field as the soil-moisture content increased. Water levels measured in the sprinkler-irrigated field did not respond to irrigation. Discharge from the valley-fill aquifer to the Sevier River in Panguitch Valley is about 53,570 acre-feet per year.Water levels measured in wells from 1951 to 1989 tend to fluctuate with the quantity of precipitation falling at higher elevations. Ground-water discharge to the Sevier River in Panguitch Valley causes a general increase in the specific conductance of the river in a downstream direction.A three-layered ground-water-flow model was used to simulate the effects of changes in irrigation practices am increased ground-water withdrawals in Panguitch Valley. The establishment of initial conditions consisted of comparing simulated water levels and simulated gains and losses from the Sevier River and selected canals with values measured during the 1988 irrigation season. The model was calibrated by comparing water-level changes measured from 1961 to 1963 to simulated changes. A simulated change from flood to sprinkler irrigation resulted in a maximum decline in water level of 0.9 feet after the first year of change. Simulating additional discharge from wells resulted in drawdowns of about 20 feet after the first year of pumping.

Water-Quality Conditions of Chester Creek, Anchorage, Alaska, 1998-2001

USGS Publications Warehouse

Glass, Roy L.; Ourso, Robert T.

2006-01-01

Between October 1998 and September 2001, the U.S. Geological Survey's National Water-Quality Assessment Program evaluated the water-quality conditions of Chester Creek, a stream draining forest and urban settings in Anchorage, Alaska. Data collection included water, streambed sediments, lakebed sediments, and aquatic organisms samples from urban sites along the stream. Urban land use ranged from less than 1 percent of the basin above the furthest upstream site to 46 percent above the most downstream site. Findings suggest that water quality of Chester Creek declines in the downstream direction and as urbanization in the watershed increases. Water samples were collected monthly and during storms at a site near the stream's mouth (Chester Creek at Arctic Boulevard) and analyzed for major ions and nutrients. Water samples collected during water year 1999 were analyzed for selected pesticides and volatile organic compounds. Concentrations of fecal-indicator bacteria were determined monthly during calendar year 2000. During winter, spring, and summer, four water samples were collected at a site upstream of urban development (South Branch of South Fork Chester Creek at Tank Trail) and five from an intermediate site (South Branch of South Fork Chester Creek at Boniface Parkway). Concentrations of calcium, magnesium, sodium, chloride, and sulfate in water increased in the downstream direction. Nitrate concentrations were similar at the three sites and all were less than the drinking-water standard. About one-quarter of the samples from the Arctic Boulevard site had concentrations of phosphorus that exceeded the U.S. Environmental Protection Agency (USEPA) guideline for preventing nuisance plant growth. Water samples collected at the Arctic Boulevard site contained concentrations of the insecticide carbaryl that exceeded the guideline for protecting aquatic life. Every water sample revealed a low concentration of volatile organic compounds, including benzene, toluene, tetrachloroethylene, methyl tert-butyl ether, and chloroform. No water samples contained volatile organic compounds concentrations that exceeded any USEPA drinking-water standard or guideline. Fecal-indicator bacteria concentrations in water from the Arctic Boulevard site commonly exceeded Federal and State guidelines for water-contact recreation. Concentrations of cadmium, copper, lead, and zinc in streambed sediments increased in the downstream direction. Some concentrations of arsenic, chromium, lead, and zinc in sediments were at levels that can adversely affect aquatic organisms. Analysis of sediment chemistry in successive lakebed-sediment layers from Westchester Lagoon near the stream's mouth provided a record of water-quality trends since about 1970. Concentrations of lead have decreased from peak levels in the mid-1970s, most likely because of removing lead from gasoline and lower lead content in other products. However, concen-trations in recently-deposited lakebed sediments are still about 10 times greater than measured in streambed sediments at the upstream Tank Trail site. Zinc concentrations in lakebed sediments also increased in the early 1970s to levels that exceeded guidelines to protect aquatic life and have remained at elevated but variable levels. Pyrene, benz[a]anthracene, and phenanthrene in lakebed sediments also have varied in concentrations and have exceeded protection guidelines for aquatic life since the 1970s. Concentrations of dichloro-diphenyl-trichloroethane, polychlorinated biphenyls (PCBs), or their by-products generally were highest in lakebed sediments deposited in the 1970s. More recent sediments have concentrations that vary widely and do not show distinct temporal trends. Tissue samples of whole slimy sculpin (Cottus cognatus), a non-migratory species of fish, showed con-centrations of trace elements and organic contaminants. Of the constituents analyzed, only selenium concentra-tions showed levels of potential concern for

Cold Heat Release Characteristics of Solidified Oil Droplet-Water Solution Latent Heat Emulsion by Air Bubbles

NASA Astrophysics Data System (ADS)

Inaba, Hideo; Morita, Shin-Ichi

The present work investigates the cold heat-release characteristics of the solidified oil droplets (tetradecane, C14H30, freezing point 278.9 K)/water solution emulsion as a latent heat-storage material having a low melting point. An air bubbles-emulsion direct-contact heat exchange method is selected for the cold heat-results from the solidified oil droplet-emulsion layer. This type of direct-contact method results in the high thermal efficiency. The diameter of air bubbles in the emulsion increases as compared with that in the pure water. The air bubbles blown from a nozzle show a strong mixing behavior during rising in the emulsion. The temperature effectiveness, the sensible heat release time and the latent heat release time have been measured as experimental parameters. The useful nondimensional emulsion level equations for these parameters have been derived in terms of the nondimensional emalsion level expressed the emulsion layer dimensions, Reynolds number for air flow, Stefan number and heat capacity ratio.

Increasing extreme water level flood risk as a result of future sea-level rise: A case study on a coastal city in China

NASA Astrophysics Data System (ADS)

Feng, A.; Wu, S.

2016-12-01

Extreme water levels, caused by the joint occurrence of storm surges and high tides, always lead to super floods along coastlines. In the context of climate change, this study explored the impact of future sea-level rise on the flood risk of extreme water levels. Using Rongcheng City in Shandong Province, China as a case study, flooded area, expected direct damage losses, and affected population and GDP were assessed for 2050 and 2100 under three greenhouse gas concentration Representative Concentration Pathways (RCP) scenarios, 2.6, 4.5, and 8.5. Results indicate that, as a result of sea-level rise induced by climate change, the flooded areas of Rongcheng City would increase by 3.23% to 10.64% in 2050 and by as much as 4.98% to 19.87% in 2100, compared with current recurrence periods. Residential land and farmland are at greatest risk of flooding in terms of exposure and losses than other land-use types, and under a high degree RCP 8.5 scenario, expected damage losses would be between 59.84 billion and 86.45 billion in 2050. Results show that the increase in total direct damage losses would reach an average of 60% in 2100 as a result of a 0.82 m sea-level rise. Similarly, affected population and GDP would increase by between 4.95% and 13.87% and between 3.66% and 10.95% in 2050, and by as much as 7.69% to 29.01% and 5.30% to 20.50% in 2100. This study shows that sea-level rise significantly shortens recurrence periods of extreme water levels, makes extreme flood events more frequent, and exacerbates the risk of future flooding. Our results suggest that, if there is no adaptation, sea-level rise will greatly increase the risk of flooding and severely impact human habitability along coastlines.

Managing the financial risk of low water levels in Great Lakes with index-based contracts

NASA Astrophysics Data System (ADS)

Meyer, E.; Characklis, G. W.; Brown, C. M.; Moody, P.

2014-12-01

Low water levels in the Great Lakes have recently had significant financial impacts on the region's commercial shipping, responsible for transporting millions of dollars' worth of bulk goods each year. Low lake levels can significantly affect shipping firms, as cargo capacity is a function of draft, or the distance between water level and the ship's bottom. Draft increases with weight, and lower lake levels force ships to reduce cargo to prevent running aground in shallow harbors, directly impacting the finances of shipping companies. Risk transfer instruments may provide adaptable, yet unexplored, alternatives for managing these financial risks, at significantly less expense than more traditional solutions (e.g., dredging). Index-based financial instruments can be particularly attractive as contract payouts are directly linked to well-defined transparent metrics (e.g., lake levels), eliminating the need for subjective adjustors, as well as concerns over moral hazard. In developing such instruments, a major challenge is identifying an index that is well correlated with financial losses, and thus a contract that reliably pays out when losses are experienced (low basis risk). In this work, a relationship between lake levels and shipping revenues is developed, and actuarial analyses of the frequency and magnitude of revenue losses is completed using this relationship and synthetic water level data. This analysis is used to develop several types of index-based contracts. A standardized suite of binary contracts is developed, with each indexed to lake levels and priced according to predefined thresholds. These are combined to form portfolios with different objectives (e.g. options, collars), with optimal portfolio structure and length of coverage determined by limiting basis risk and contract cost, using simulations over the historic dataset. Results suggest that portfolios of these binary contracts can substantially reduce the risk of financial losses during periods of low lake level at a cost of only 1-3% of total revenues.

Colors of Alien Worlds from Direct Imaging Exoplanet Missions

NASA Astrophysics Data System (ADS)

Hu, Renyu

2016-01-01

Future direct-imaging exoplanet missions such as WFIRST will measure the reflectivity of exoplanets at visible wavelengths. Most of the exoplanets to be observed will be located further away from their parent stars than is Earth from the Sun. These "cold" exoplanets have atmospheric environments conducive for the formation of water and/or ammonia clouds, like Jupiter in the Solar System. I find the mixing ratio of methane and the pressure level of the uppermost cloud deck on these planets can be uniquely determined from their reflection spectra, with moderate spectral resolution, if the cloud deck is between 0.6 and 1.5 bars. The existence of this unique solution is useful for exoplanet direct imaging missions for several reasons. First, the weak bands and strong bands of methane enable the measurement of the methane mixing ratio and the cloud pressure, although an overlying haze layer can bias the estimate of the latter. Second, the cloud pressure, once derived, yields an important constraint on the internal heat flux from the planet, and thus indicating its thermal evolution. Third, water worlds having H2O-dominated atmospheres are likely to have water clouds located higher than the 10-3 bar pressure level, and muted spectral absorption features. These planets would occupy a confined phase space in the color-color diagrams, likely distinguishable from H2-rich giant exoplanets by broadband observations. Therefore, direct-imaging exoplanet missions may offer the capability to broadly distinguish H2-rich giant exoplanets versus H2O-rich super-Earth exoplanets, and to detect ammonia and/or water clouds and methane gas in their atmospheres.

Ground Water in the Southern Lihue Basin, Kauai, Hawaii

USGS Publications Warehouse

Izuka, Scot K.; Gingerich, Stephen B.

1998-01-01

A multi-phased study of ground-water resources, including well drilling, aquifer tests, analysis of ground-water discharge, and numerical ground-water modeling, indicates that the rocks of the southern Lihue Basin, Kauai, have permeabilities that are much lower than in most other areas of ground-water development in the Hawaiian islands. The regional hydraulic conductivity of the Koloa Volcanics, which dominates fresh ground-water flow in the basin, is about 0.275 foot per day. The Waimea Canyon Basalt which surrounds the basin and underlies the Koloa Volcanics within the basin is intruded by dikes that reduce the bulk hydraulic conductivity of the rocks to about 1.11 feet per day. The low permeabilities result in steeper head gradients compared with other areas in the Hawaiian islands, and a higher proportion of ground-water discharging to streams than to the ocean. Water levels rise from near sea level at the coast to several hundreds of feet above sea level at the center of the basin a few miles inland. The high inland water levels are part of a completely saturated ground-water system. Because of the low regional hydraulic conductivity and high influx of water from recharge in the southern Lihue Basin, the rocks become saturated nearly to the surface and a variably saturated/unsaturated (perched) condition is not likely to exist. Streams incising the upper part of the aquifer drain ground water and keep the water levels just below the surface in most places. Streams thus play an important role in shaping the water table in the southern Lihue Basin. At least 62 percent of the ground water discharging from the aquifer in the southern Lihue Basin seeps to streams; the remainder seeps directly to the ocean or is withdrawn by wells.

Predevelopment Water-Level Contours for Aquifers in the Rainier Mesa and Shoshone Mountain area of the Nevada Test Site, Nye County, Nevada

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

Joseph M. Fenelon; Randell J. Laczniak; and Keith J. Halford

2008-06-24

Contaminants introduced into the subsurface of the Nevada Test Site at Rainier Mesa and Shoshone Mountain by underground nuclear testing are of concern to the U.S. Department of Energy and regulators responsible for protecting human health and safety. Although contaminants were introduced into low-permeability rocks above the regional flow system, the potential for contaminant movement away from the underground test areas and into the accessible environment is greatest by ground-water transport. The primary hydrologic control on this transport is evaluated and examined through a series of contour maps developed to represent the water-level distribution within each of the major aquifersmore » underlying the area. Aquifers were identified and their extents delineated by merging and analyzing multiple hydrostratigraphic framework models developed by other investigators from existing geologic information. The contoured water-level distribution in each major aquifer was developed from a detailed evaluation and assessment of available water-level measurements. Multiple spreadsheets that accompany this report provide pertinent water-level and geologic data by well or drill hole. Aquifers are mapped, presented, and discussed in general terms as being one of three aquifer types—volcanic aquifer, upper carbonate aquifer, or lower carbonate aquifer. Each of these aquifer types was subdivided and mapped as independent continuous and isolated aquifers, based on the continuity of its component rock. Ground-water flow directions, as related to the transport of test-generated contaminants, were developed from water-level contours and are presented and discussed for each of the continuous aquifers. Contoured water-level altitudes vary across the study area and range from more than 5,000 feet in the volcanic aquifer beneath a recharge area in the northern part of the study area to less than 2,450 feet in the lower carbonate aquifer in the southern part of the study area. Variations in water-level altitudes within any single continuous aquifer range from a few hundred feet in a lower carbonate aquifer to just more than 1,100 feet in a volcanic aquifer. Flow directions throughout the study area are dominantly southward with minor eastward or westward deviations. Primary exceptions are westward flow in the northern part of the volcanic aquifer and eastward flow in the eastern part of the lower carbonate aquifer. Northward flow in the upper and lower carbonate aquifers in the northern part of the study area is possible but cannot be substantiated because data are lacking. Interflow between continuous aquifers is evaluated and mapped to define major flow paths. These flow paths delineate tributary flow systems, which converge to form the regional ground-water flow system. The implications of these tributary flow paths in controlling transport away from the underground test areas at Rainier Mesa and Shoshone Mountain are discussed. The obvious data gaps contributing to uncertainties in the delineation of aquifers and development of water-level contours are identified and evaluated.« less

Predevelopment Water-Level Contours for Aquifers in the Rainier Mesa and Shoshone Mountain area of the Nevada Test Site, Nye County, Nevada

USGS Publications Warehouse

Fenelon, Joseph M.; Laczniak, Randell J.; Halford, Keith J.

2008-01-01

Contaminants introduced into the subsurface of the Nevada Test Site at Rainier Mesa and Shoshone Mountain by underground nuclear testing are of concern to the U.S. Department of Energy and regulators responsible for protecting human health and safety. Although contaminants were introduced into low-permeability rocks above the regional flow system, the potential for contaminant movement away from the underground test areas and into the accessible environment is greatest by ground-water transport. The primary hydrologic control on this transport is evaluated and examined through a series of contour maps developed to represent the water-level distribution within each of the major aquifers underlying the area. Aquifers were identified and their extents delineated by merging and analyzing multiple hydrostratigraphic framework models developed by other investigators from existing geologic information. The contoured water-level distribution in each major aquifer was developed from a detailed evaluation and assessment of available water-level measurements. Multiple spreadsheets that accompany this report provide pertinent water-level and geologic data by well or drill hole. Aquifers are mapped, presented, and discussed in general terms as being one of three aquifer types?volcanic aquifer, upper carbonate aquifer, or lower carbonate aquifer. Each of these aquifer types was subdivided and mapped as independent continuous and isolated aquifers, based on the continuity of its component rock. Ground-water flow directions, as related to the transport of test-generated contaminants, were developed from water-level contours and are presented and discussed for each of the continuous aquifers. Contoured water-level altitudes vary across the study area and range from more than 5,000 feet in the volcanic aquifer beneath a recharge area in the northern part of the study area to less than 2,450 feet in the lower carbonate aquifer in the southern part of the study area. Variations in water-level altitudes within any single continuous aquifer range from a few hundred feet in a lower carbonate aquifer to just more than 1,100 feet in a volcanic aquifer. Flow directions throughout the study area are dominantly southward with minor eastward or westward deviations. Primary exceptions are westward flow in the northern part of the volcanic aquifer and eastward flow in the eastern part of the lower carbonate aquifer. Northward flow in the upper and lower carbonate aquifers in the northern part of the study area is possible but cannot be substantiated because data are lacking. Interflow between continuous aquifers is evaluated and mapped to define major flow paths. These flow paths delineate tributary flow systems, which converge to form the regional ground-water flow system. The implications of these tributary flow paths in controlling transport away from the underground test areas at Rainier Mesa and Shoshone Mountain are discussed. The obvious data gaps contributing to uncertainties in the delineation of aquifers and development of water-level contours are identified and evaluated.

33 CFR 207.170 - Federal Dam, Oklawaha River, Moss Bluff, Fla.; pool level.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Federal Dam, Oklawaha River, Moss..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170 Federal Dam, Oklawaha River... high water, the discharge past the dam shall be regulated in such manner as he may direct until he...

33 CFR 207.170 - Federal Dam, Oklawaha River, Moss Bluff, Fla.; pool level.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Federal Dam, Oklawaha River, Moss..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170 Federal Dam, Oklawaha River... high water, the discharge past the dam shall be regulated in such manner as he may direct until he...

Water clustering in glassy polymers.

PubMed

Davis, Eric M; Elabd, Yossef A

2013-09-12

In this study, water solubility and water clustering in several glassy polymers, including poly(methyl methacrylate) (PMMA), poly(styrene) (PS), and poly(vinylpyrrolidone) (PVP), were measured using both quartz spring microbalance (QSM) and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy. Specifically, QSM was used to determine water solubility, while FTIR-ATR spectroscopy provided a direct, molecular-level measurement of water clustering. The Flory-Huggins theory was employed to obtain a measure of water-polymer interaction and water solubility, through both prediction and regression, where the theory failed to predict water solubility in both PMMA and PVP. Furthermore, a comparison of water clustering between direct FTIR-ATR spectroscopy measurements and predictions from the Zimm-Lundberg clustering analysis produced contradictory results. The failure of the Flory-Huggins theory and Zimm-Lundberg clustering analysis to describe water solubility and water clustering, respectively, in these glassy polymers is in part due to the equilibrium constraints under which these models are derived in contrast to the nonequilibrium state of glassy polymers. Additionally, FTIR-ATR spectroscopy results were compared to temperature-dependent diffusivity data, where a correlation between the activation energy for diffusion and the measured water clustering was observed.

Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models

USGS Publications Warehouse

Storlazzi, Curt D.; Berkowitz, Paul; Reynolds, Michelle H.; Logan, Joshua B.

2013-01-01

Two inundation events in 2011 underscored the potential for elevated water levels to damage infrastructure and affect terrestrial ecosystems on the low-lying Northwestern Hawaiian Islands in the Papahānaumokuākea Marine National Monument. The goal of this study was to compare passive "bathtub" inundation models based on geographic information systems (GIS) to those that include dynamic water levels caused by wave-induced set-up and run-up for two end-member island morphologies: Midway, a classic atoll with islands on the shallow (2-8 m) atoll rim and a deep, central lagoon; and Laysan, which is characterized by a deep (20-30 m) atoll rim and an island at the center of the atoll. Vulnerability to elevated water levels was assessed using hindcast wind and wave data to drive coupled physics-based numerical wave, current, and water-level models for the atolls. The resulting model data were then used to compute run-up elevations using a parametric run-up equation under both present conditions and future sea-level-rise scenarios. In both geomorphologies, wave heights and wavelengths adjacent to the island shorelines increased more than three times and four times, respectively, with increasing values of sea-level rise, as more deep-water wave energy could propagate over the atoll rim and larger wind-driven waves could develop on the atoll. Although these increases in water depth resulted in decreased set-up along the islands’ shorelines, the larger wave heights and longer wavelengths due to sea-level rise increased the resulting wave-induced run-up. Run-up values were spatially heterogeneous and dependent on the direction of incident wave direction, bathymetry, and island configuration. Island inundation was modeled to increase substantially when wave-driven effects were included, suggesting that inundation and impacts to infrastructure and terrestrial habitats will occur at lower values of predicted sea-level rise, and thus sooner in the 21st century, than suggested by passive GIS-based "bathtub" inundation models. Lastly, observations and the modeling results suggest that classic atolls with islands on a shallow atoll rim are more susceptible to the combined effects of sea-level rise and wave-driven inundation than atolls characterized by a deep atoll rim.

Ground-water levels, predevelopment ground-water flow, and stream-aquifer relations in the vicinity of the Savannah River Site, Georgia and South Carolina

USGS Publications Warehouse

Clarke, John S.; West, Christopher T.

1998-01-01

Ground-water levels, predevelopment ground-water flow, and stream-aquifer relations in the vicinity of the U.S. Department of Energy Savannah River Site, Georgia and South Carolina, were evaluated as part of a cooperative study between the U.S. Geological Survey, U.S. Department of Energy, and Georgia Department of Natural Resources. As part of this evaluation: (1) ground-water-level fluctuations and trends in three aquifer systems in sediment of Cretaceous and Tertiary age were described and related to patterns of ground-water use and precipitations; (2) a conceptual model ofthe stream-aquifer flow system was developed; (3) the predevelopment ground-water flow system, configuration of potentiometric surfaces, trans-river flow, and recharge-discharge relations were described; and (4) stream-aquifer relations and the influence of river incision on ground-water flow and stream-aquifer relations were described. The 5,147-square mile study area is located in the northern part of the Coastal Plain physiographic province of Georgia and South Carolina. Coastal Plain sediments comprise three aquifer systems consisting of seven aquifers that are separated hydraulically by confining units. The aquifer systems are, in descending order: (1) the Floridan aquifer system?consisting of the Upper Three Runs and Gordon aquifers in sediments of Eocene age; (2) the Dublin aquifer system?consisting of the Millers Pond, upper Dublin, and lower Dublin aquifers in sediments of Paleocene-Late Cretaceous age; and (3) the Midville aquifer system?consisting of the upper Midville and lower Midville aquifers in sediments of Late Cretaceous age. The Upper Three Runs aquifer is the shallowest aquifer and is unconfined to semi-confined throughout most of the study area. Ground-water levels in the Upper Three Runs aquifer respond to a local flow system and are affected mostly by topography and climate. Ground-water flow in the deeper, Gordon aquifer and Dublin and Midville aquifer systems is characterized by local flow near outcrop areas to the north, changing to intermediate flow and then regional flow downdip (southeastward) as the aquifers become more deeply buried. Water levels in these deeper aquifers show a pronounced response to topography and climate in the vicinity of outcrops, and diminish southeastward where the aquifer is more deeply buried. Stream stage and pumpage affect ground-water levels in these deeper aquifers to varying degrees throughout the study area. The geologic characteristics of the Savannah River alluvial valley substantially control the configuration of potentiometric surfaces, ground-water-flow directions, and stream-aquifer relations. Data from 18 shallow borings indicate incision into each aquifer by the paleo Savannah River channel and subsequent infill of permeable alluvium, allowing for direct hydraulic connection between aquifers and the Savannah River along parts of its reach. This hydraulic connection may be the cause of large ground-water discharge to the river near Jackson, S.C., where the Gordon aquifer is in contact with Savannah River alluvium, and also the cause of lows or depressions formed in the potentiometric surfaces of confined aquifers that are in contact with the alluvium. Ground water in these aquifers flows toward the depressions. The influence of the river is diminished downstream where the aquifers are deeply buried, and upstream and downstream ground-water flow is possibly separated by a water divide or 'saddle'. Water-level data indicate that saddle features probably exist in the Gordon aquifer and Dublin aquifer system, and also might be present in the Midville aquifer system. Ground-water levels respond seasonally or in long term to changes in precipitation, evapotranspiration, pumpage, and river stage. Continuous water-level data and water-levels measured in a network of 271 wells during the Spring (May) and Fall (October) in 1992, indicate that seasonal water-level changes generally are

Rate of disappearance of gas bubble trauma signs in juvenile salmonids

USGS Publications Warehouse

Hans, K.M.; Mesa, M.G.; Maule, A.G.

1999-01-01

To assess the rate of disappearance of gas bubble trauma (GBT) signs in juvenile salmonids, we exposed spring chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss to water containing high levels of dissolved gas supersaturation (DGS) for a time period sufficient to induce signs of GBT, reduced the DGS to minimal levels, and then sampled fish through time to document changes in severity of GBT. Because of the tendency of GBT signs to dissipate at different rates, we conducted trials focusing on emboli (bubbles) in the gill filaments and lateral line and separate trials that focused on bubbles in the external surfaces (fins, eyes, and opercula). Bubbles in gill filaments dissipated almost completely within 2 h after transfer of fish to water of nearly normal DGS (104%), whereas bubbles in the lateral line dissipated to negligible levels within 5 h. Bubbles on external surfaces were more persistent through time than they were in gill filaments and the lateral line. Although typically dissipating to low levels within 48 h, external bubbles sometimes remained for 4 d. Assuming a direct relation exists between easily observable signs and direct mortality, our results suggest that fish can recover quickly from the potentially lethal effects of DGS once they move from water with high DGS to water of almost normal gas saturation. These results should be of fundamental importance to fishery managers interpreting the results of monitoring for the severity and prevalence of GBT in juvenile salmonids in the Columbia River system and perhaps elsewhere.

SOFIA Water Vapor Monitor Design

NASA Technical Reports Server (NTRS)

Cooper, R.; Roellig, T. L.; Yuen, L.; Shiroyama, B.; Meyer, A.; Devincenzi, D. (Technical Monitor)

2002-01-01

The SOFIA Water Vapor Monitor (WVM) is a heterodyne radiometer designed to determine the integrated amount of water vapor along the telescope line of sight and directly to the zenith. The basic technique that was chosen for the WVM uses radiometric measurements of the center and wings of the 183.3 GHz rotational line of water to measure the water vapor. The WVM reports its measured water vapor levels to the aircraft Mission Controls and Communication System (MCCS) while the SOFIA observatory is in normal operation at flight altitude. The water vapor measurements are also available to other scientific instruments aboard the observatory. The electrical, mechanical and software design of the WVM are discussed.

Ultra-trace level determination of diquat and paraquat residues in surface and drinking water using ion-pair liquid chromatography with tandem mass spectrometry: a comparison of direct injection and solid-phase extraction methods.

PubMed

Oh, Jin-Aa; Lee, Jun-Bae; Lee, Soo-Hyung; Shin, Ho-Sang

2014-10-01

Direct injection and solid-phase extraction methods for the determination of diquat and paraquat in surface and drinking water were developed using liquid chromatography with tandem mass spectrometry. The signal intensities of analytes based on six ion-pairing reagents were compared with each other, and 12.5 mM nonafluoropentanoic acid was selected as the best suited amongst them. A clean-up method was developed using Oasis hydrophilic-lipophilic balance; this was compared to the direct injection method, with respect to limits of detection, interference, precision, and accuracy. Limits of quantification of diquat and paraquat were 0.03 and 0.01 μg/L using the direct injection method, and 0.002 and 0.001 μg/L using the hydrophilic-lipophilic balance method. When the hydrophilic-lipophilic balance method was used to analyze target compounds in 114 surface water and 30 drinking water samples, paraquat and diquat were detected within a concentration range of 0.001-0.12 and 0.002-0.038 μg/L in surface water, respectively. When the direct injection method was used to analyze target compounds in the same samples, the detected concentrations of paraquat and diquat were within 25% in samples being >0.015 μg/L using the hydrophilic-lipophilic balance method. The liquid chromatography with tandem mass spectrometry method using direct injection can thus be used for routine monitoring of paraquat and diquat in surface and drinking water. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Co-spray Drying with HPMC as a Platform to Improve Direct Compaction Properties of Various Tablet Fillers.

PubMed

Li, JinZhi; Zhao, LiJie; Lin, Xiao; Shen, Lan; Feng, Yi

2017-11-01

Many commonly used tablet fillers are not suitable for direct compaction process due to insufficient properties, mainly of flowability and compactability. This work therefore aimed to use co-spray drying with HPMC as a platform to improve direct compaction properties of various tablet fillers. Starch, calcium hydrogen phosphate dihydrate (DCPD), and mannitol were chosen as a representative of three types of commonly used fillers (i.e. organic macromolecules, water-insoluble inorganic salts, and water-soluble small molecular carbohydrates), respectively. The five-level central composite design-response surface methodology was used (i) to investigate the effects of HPMC level and solid content of the feed on various powder, tableting, and tablet properties of composite excipients, and (ii) to optimize the composition. The results showed that the impacts of the two factors on various properties of composite excipients showed great similarity, despite of significantly different primary properties of the parent fillers, and the HPMC level was the main contributor to the majority of the impacts. An increase in HPMC level significantly improved tablet tensile strength and various tableting parameters. For all the three fillers, their optimized composite excipients provided by the established models showed excellent performances as predicted. The platform suggested is confirmed to be effective and promising.

Ground-water levels, water quality, and potential effects of toxic-substance spills or cessation of quarry dewatering near a municipal ground-water supply, southeastern Franklin County, Ohio

USGS Publications Warehouse

Sedam, A.C.; Eberts, S.M.; Bair, E.S.

1989-01-01

A newly completed municipal ground-water supply that produces from a sand and gravel aquifer in southern Franklin County, Ohio, may be susceptible to potential sources of pollution. Among these are spills of toxic substances that could enter recharge areas of the aquifer or be carried by surface drainage and subsequently enter the aquifer by induced infiltration. Ground water of degraded quality also is present in the vicinity of several landfills located upstream from the municipal supply. Local dewatering by quarrying operations has created a ground-water divide which, at present, prevents direct movement of the degraded ground water to the municipal supply. In addition, the dewatering has held water levels at the largest landfills below the base of the landfill. Should the dewatering cease, concern would be raised regarding the rise of water levels at this landfills and transport of contaminants through the aquifer to the Scioto River and subsequently by the river to the well field. From June 1984 through July 1986, the U.S. Geological Survey, in cooperation with the City of Columbus, Ohio, investigated the relations among the ground-water supply and potential sources of contamination by means of an observation-well network and a program of measuring water levels and sampling for water quality. Sample collections included those made to determine the baseline levels of organic chemicals and metals, as well as periodic sampling and analysis for common constituents to evaluate any changes taking place in the system. Finally, a steady-state, three-dimensional numerical model was used to determine ground-water flow directions and average ground-water velocities to asses potential effects of toxic-substance spills. The model also was used to simulate changes in the ground-water flow system that could result if part or all of the quarry dewatering ceased. Few of the organic-chemical and metal constituents analyzed for were present at detectable levels. With respect to chemical analysis of water and soil materials reported in earlier studies, no new problem areas were discovered as a result of either the baseline or periodic samplings. Model simulations suggest that, under March 1986 conditions, a toxic-substance spill along the major highways in the northern two-thirds of the study area eventually could discharge into one of the two quarries being dewatered or into the Scioto River. A toxic-substance spill in the southern one-third of the study area ultimately may discharge into the Scioto River, Big Walnut Creek, or possibly into the municipal ground-water supply. Model simulations also indicate that concentrated landfill leachate probably would not reach the municipal ground-water supply under current or well-field pumping conditions if dewatering ceased at either or both of the quarries.

Potential of capillary-column-switching liquid chromatography-tandem mass spectrometry for the quantitative trace analysis of small molecules. Application to the on-line screening of drugs in water.

PubMed

Pitarch, Elena; Hernandez, Felix; ten Hove, Jan; Meiring, Hugo; Niesing, Willem; Dijkman, Ellen; Stolker, Linda; Hogendoorn, Elbert

2004-03-26

We have investigated the potential of capillary-column-switching liquid chromatography coupled to tandem mass spectrometry (cLC-MS-MS) for the quantitative on-line trace analysis of target compounds in aqueous solutions. The technical design of the nano-scale cLC system developed at our Institute for peptide and protein identification has been tested and evaluated for the direct trace analysis of drugs in water samples. Sulphametoxazole, bezafibrate, metoprolol, carbamazepine and bisoprolol occurring frequently in Dutch waters, were selected as test compounds. Adequate conditions for trapping, elution and MS-MS detection were investigated by employing laboratory made 200 microm i.d. capillary columns packed with 5 microm aqua C18 material. In the final cLC-MS-MS conditions, a 1 cm length trapping column and a 4 cm length analytical column were selected. Under these conditions, the target compounds could be directly determined in water down to a level of around 50 ng/l employing only 25 microl of water sample. Validation was done by recovery experiments in ground-, surface- and drinking-water matrices as well as by the analysis of water samples with incurred residues and previously analyzed with a conventional procedure involving off-line solid-phase extraction and narrow-bore LC with MS-MS detection. The new methodology provided recoveries (50-500 ng/l level) between 50 and 114% with RSDs (n = 3, each level) below 20% for most of the compounds. Despite the somewhat less analytical performance in comparison to the conventional procedure, the on-line approach of the new methodology is very suitable for screening of drugs in aqueous samples.

Sensitivity Analysis as a Tool to assess Energy-Water Nexus in India

NASA Astrophysics Data System (ADS)

Priyanka, P.; Banerjee, R.

2017-12-01

Rapid urbanization, population growth and related structural changes with-in the economy of a developing country act as a stressor on energy and water demand, which forms a well-established energy-water nexus. Energy-water nexus is thoroughly studied at various spatial scales viz. city level, river basin level and national level- to guide different stakeholders for sustainable management of energy and water. However, temporal dimensions of energy-water nexus at national level have not been thoroughly investigated because of unavailability of relevant time-series data. In this study we investigated energy-water nexus at national level using environmentally-extended input-output tables for Indian economy (2004-2013) as provided by EORA database. Perturbation based sensitivity analysis is proposed to highlight the critical nodes of interactions among economic sectors which is further linked to detect the synergistic effects of energy and water consumption. Technology changes (interpreted as change in value of nodes) results in modification of interactions among economic sectors and synergy is affected through direct as well as indirect effects. Indirect effects are not easily understood through preliminary examination of data, hence sensitivity analysis within an input-output framework is important to understand the indirect effects. Furthermore, time series data helps in developing the understanding on dynamics of synergistic effects. We identified the key sectors and technology changes for Indian economy which will provide the better decision support for policy makers about sustainable use of energy-water resources in India.

Direct exfoliation and dispersion of two-dimensional materials in pure water via temperature control.

PubMed

Kim, Jinseon; Kwon, Sanghyuk; Cho, Dae-Hyun; Kang, Byunggil; Kwon, Hyukjoon; Kim, Youngchan; Park, Sung O; Jung, Gwan Yeong; Shin, Eunhye; Kim, Wan-Gu; Lee, Hyungdong; Ryu, Gyeong Hee; Choi, Minseok; Kim, Tae Hyeong; Oh, Junghoon; Park, Sungjin; Kwak, Sang Kyu; Yoon, Suk Wang; Byun, Doyoung; Lee, Zonghoon; Lee, Changgu

2015-09-15

The high-volume synthesis of two-dimensional (2D) materials in the form of platelets is desirable for various applications. While water is considered an ideal dispersion medium, due to its abundance and low cost, the hydrophobicity of platelet surfaces has prohibited its widespread use. Here we exfoliate 2D materials directly in pure water without using any chemicals or surfactants. In order to exfoliate and disperse the materials in water, we elevate the temperature of the sonication bath, and introduce energy via the dissipation of sonic waves. Storage stability greater than one month is achieved through the maintenance of high temperatures, and through atomic and molecular level simulations, we further discover that good solubility in water is maintained due to the presence of platelet surface charges as a result of edge functionalization or intrinsic polarity. Finally, we demonstrate inkjet printing on hard and flexible substrates as a potential application of water-dispersed 2D materials.

Comparison of UV photolysis, nanofiltration, and their combination to remove hormones from a drinking water source and reduce endocrine disrupting activity.

PubMed

Sanches, Sandra; Rodrigues, Alexandre; Cardoso, Vitor V; Benoliel, Maria J; Crespo, João G; Pereira, Vanessa J

2016-06-01

A sequential water treatment combining low pressure ultraviolet direct photolysis with nanofiltration was evaluated to remove hormones from water, reduce endocrine disrupting activity, and overcome the drawbacks associated with the individual processes (production of a nanofiltration-concentrated retentate and formation of toxic by-products). 17β-Estradiol, 17α-ethinylestradiol, estrone, estriol, and progesterone were spiked into a real water sample collected after the sedimentation process of a drinking water treatment plant. Even though the nanofiltration process alone showed similar results to the combined treatment in terms of the water quality produced, the combined treatment offered advantage in terms of the load of the retentate and decrease in the endocrine-disrupting activity of the samples. Moreover, the photolysis by-products produced, with higher endocrine disrupting activity than the parent compounds, were effectively retained by the membrane. The combination of direct LP/UV photolysis with nanofiltration is promising for a drinking water utility that needs to cope with sudden punctual discharges or deterioration of the water quality and wants to decrease the levels of chemicals in the nanofiltration retentate.

USACE Extreme Sea levels

DTIC Science & Technology

2014-03-14

with expected changes due to climate change. (tropicals and extra-tropicals) Ivan provided some good information on work being done on tropical...Pattiaratchi, C., Jensen, J., 2013. Estimating extreme water level probabilities: a comparison of the direct methods and recommendations for best practise ...sites: site-by-site analyses. Proudman Oceanographic Laboratory , Internal Document, No. 65, 229pp. Dixon, M.J., Tawn, J.A. (1995) Extreme sea-levels

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

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.

Preliminary Water-Table Map and Water-Quality Data for Part of the Matanuska-Susitna Valley, Alaska, 2005

USGS Publications Warehouse

Moran, Edward H.; Solin, Gary L.

2006-01-01

The Matanuska-Susitna Valley is in the northeastern part of the Cook Inlet Basin, Alaska, an area experiencing rapid population growth and development proximal to many lakes. Here water commonly flows between lakes and ground water, indicating interrelation between water quantity and quality. Thus concerns exist that poorer quality ground water may degrade local lake ecosystems. This concern has led to water-quality sampling in cooperation with the Alaska Department of Environmental Conservation and the Matanuska-Susitna Borough. A map showing the estimated altitude of the water table illustrates potential ground-water flow directions and areas where ground- and surface-water exchanges and interactions might occur. Water quality measured in selected wells and lakes indicates some differences between ground water and surface water. 'The temporal and spatial scarcity of ground-water-level and water-quality data limits the analysis of flow direction and water quality. Regionally, the water-table map indicates that ground water in the eastern and southern parts of the study area flows southerly. In the northcentral area, ground water flows predominately westerly then southerly. Although ground and surface water in most areas of the Matanuska-Susitna Valley are interconnected, they are chemically different. Analyses of the few water-quality samples collected in the area indicate that dissolved nitrite plus nitrate and orthophosphorus concentrations are higher in ground water than in surface water.'

Reduction of Altitude Diffuser Jet Noise Using Water Injection

NASA Technical Reports Server (NTRS)

Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

2014-01-01

A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

Reduction of Altitude Diffuser Jet Noise Using Water Injection

NASA Technical Reports Server (NTRS)

Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

2011-01-01

A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

OSOAA: A Vector Radiative Transfer Model of Coupled Atmosphere-Ocean System for a Rough Sea Surface Application to the Estimates of the Directional Variations of the Water Leaving Reflectance to Better Process Multi-angular Satellite Sensors Data Over the Ocean

NASA Technical Reports Server (NTRS)

Chami, Malik; LaFrance, Bruno; Fougnie, Bertrand; Chowdhary, Jacek; Harmel, Tristan; Waquet, Fabien

2015-01-01

In this study, we present a radiative transfer model, so-called OSOAA, that is able to predict the radiance and degree of polarization within the coupled atmosphere-ocean system in the presence of a rough sea surface. The OSOAA model solves the radiative transfer equation using the successive orders of scattering method. Comparisons with another operational radiative transfer model showed a satisfactory agreement within 0.8%. The OSOAA model has been designed with a graphical user interface to make it user friendly for the community. The radiance and degree of polarization are provided at any level, from the top of atmosphere to the ocean bottom. An application of the OSOAA model is carried out to quantify the directional variations of the water leaving reflectance and degree of polarization for phytoplankton and mineral-like dominated waters. The difference between the water leaving reflectance at a given geometry and that obtained for the nadir direction could reach 40%, thus questioning the Lambertian assumption of the sea surface that is used by inverse satellite algorithms dedicated to multi-angular sensors. It is shown as well that the directional features of the water leaving reflectance are weakly dependent on wind speed. The quantification of the directional variations of the water leaving reflectance obtained in this study should help to correctly exploit the satellite data that will be acquired by the current or forthcoming multi-angular satellite sensors.

Stomata of the CAM plant Tillandsia recurvata respond directly to humidity.

PubMed

Lange, O L; Medina, E

1979-01-01

Under controlled conditions, CO 2 exchange of Tillandsia recurvata showed all characteristics of CAM. During the phase of nocturnal CO 2 fixation stomata of the plant responded sensitively to changes in ambient air humidity. Dry air resulted in an increase, moist air in a decrease of diffusion resistance. The evaporative demand of the air affected the level of stomatal resistance during the entire night period. Due to stomatal closure, the total nocturnal water loss of T. recurvata was less at low than at high humidity. It is concluded that stomata respond directly to humidity and not via bulk tissue water conditions of the leaves. Such control of transpiration may optimize water use efficiency for this almost rootless, extreme epiphyte.

Mechanistic insights into the role of river sediment in the attenuation of the herbicide isoproturon.

PubMed

Trinh, Son B; Hiscock, Kevin M; Reid, Brian J

2012-11-01

Mechanistic insights into the relative contribution of sorption and biodegradation on the removal of the herbicide isoproturon (IPU) are reported. (14)C-radiorespirometry indicated very low levels of catabolic activity in IPU-undosed and IPU-dosed (0.1, 1, 100 μg L(-1)) river water (RW) and groundwater (GW) (mineralisation: <2%). In contrast, levels of catabolic activity in IPU-undosed and IPU-dosed river sediment (RS) were significantly higher (mineralisation: 14.5-36.9%). Levels of IPU catabolic competence showed a positive log-linear relationship (r(2) = 0.768) with IPU concentration present. A threshold IPU concentration of between 0.1 μg L(-1) and 1 μg L(-1) was required to significantly (p < 0.05) increase levels of catabolic activity. Given the EU Drinking Water Directive limit for a single pesticide in drinking water of <0.1 μg L(-1) this result suggests that riverbed sediment infiltration is potentially an appropriate 'natural' means of improving water quality in terms of pesticide levels at concentrations that are in keeping with regulatory limits. Copyright © 2012 Elsevier Ltd. All rights reserved.

Estimating water consumption of potential natural vegetation on global dry lands: building an LCA framework for green water flows.

PubMed

Núñez, Montserrat; Pfister, Stephan; Roux, Philippe; Antón, Assumpció

2013-01-01

This study aimed to provide a framework for assessing direct soil-water consumption, also termed green water in the literature, in life cycle assessment (LCA). This was an issue that LCA had not tackled before. The approach, which is applied during the life cycle inventory phase (LCI), consists of quantifying the net change in the evapo(transpi)ration of the production system compared to the natural reference situation. Potential natural vegetation (PNV) is used as the natural reference situation. In order to apply the method, we estimated PNV evapotranspiration adapted to local biogeographic conditions, on global dry lands, where soil-water consumption impacts can be critical. Values are reported at different spatial aggregation levels: 10-arcmin global grid, ecoregions (501 units), biomes (14 units), countries (124 units), continents, and a global average, to facilitate the assessment for different spatial information detail levels available in the LCI. The method is intended to be used in rain-fed agriculture and rainwater harvesting contexts, which includes direct soil moisture uptake by plants and rainwater harvested and then reused in production systems. The paper provides the necessary LCI method and data for further development of impact assessment models and characterization factors to evaluate the environmental effects of the net change in evapo(transpi)ration.

Engineered river flow-through to improve mine pit lake and river values.

PubMed

McCullough, Cherie D; Schultze, Martin

2018-05-30

Mine pit lakes may develop at mine closure when mining voids extend below groundwater levels and fill with water. Acid and metalliferous drainage (AMD) and salinity are common problems for pit lake water quality. Contaminated pit lake waters can directly present significant risk to both surrounding and regional communities and natural environmental values and limit beneficial end use opportunities. Pit lake waters can also discharge into surface and groundwater; or directly present risks to wildlife, stock and human end users. Riverine flow-through is increasingly proposed to mitigate or remediate pit lake water contamination using catchment scale processes. This paper presents the motivation and key processes and considerations for a flow-through pit lake closure strategy. International case studies as precedent and lessons for future application are described from pit lakes that use or propose flow-through as a key component of their mine closure design. Chemical and biological processes including dilution, absorption and flocculation and sedimentation can sustainably reduce pit lake contaminant concentrations to acceptable levels for risk and enable end use opportunities to be realised. Flow-through may be a valid mine closure strategy for pit lakes with poor water quality. However, maintenance of existing riverine system values must be foremost. We further suggest that decant river water quality may, in some circumstances, be improved; notably in examples of meso-eutrophic river waters flowing through slightly acidic pit lakes. Flow-through closure strategies must be scientifically justifiable and risk-based for both lake and receptors potentially affected by surface and groundwater transport. Due to the high-uncertainty associated with this complex strategy, biotic and physico-chemical attributes of both inflow and decant river reaches as well as lake should be well monitored. Monitoring should directly feed into an adaptive management framework discussed with key stakeholders with validation of flow-through as a sustainable strategy prior to mine relinquishment. Copyright © 2018 Elsevier B.V. All rights reserved.

Improved diffusivity of NaOH solution in autohydrolyzed poplar sapwood chips for chemi-mechanical pulp production.

PubMed

Zhang, Honglei; Hou, Qingxi; Liu, Wei; Yue, Zhen; Jiang, Xiaoya; Ma, Xixi

2018-07-01

This work investigated the changes in the physical structure of autohydrolyzed poplar sapwood chips and the effect on the subsequent alkali liquor diffusion properties for chemi-mechanical pulping (CMP). An alkali impregnation process was conducted by using the autohydrolyzed poplar sapwood with different levels of autohydrolysis intensity. The results showed that the volume porosity, water constraint capacity, and saturated water absorption of the autohydrolyzed poplar sapwood chips increased. Also, the effective capillary cross-sectional area (ECCSA) in the radial direction and the diffusion coefficients of NaOH solution in both the radial and axial directions all increased. Autohydrolysis pretreatment enhanced the alkali liquor diffusion properties in poplar sapwood chips, and the diffusion coefficient was increased more greatly in the radial direction than that in the axial direction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Residue determination and levels of glyphosate in surface waters, sediments and soils associated with oil palm plantation in Tasik Chini, Pahang, Malaysia

NASA Astrophysics Data System (ADS)

Mardiana-Jansar, K.; Ismail, B. S.

2014-09-01

Levels of glyphosate and its main metabolite were determined in surface water, soil and sediment samples from an oil palm plantation area located at Tasik Chini, Pahang, Malaysia. The optimization analytical method has been developed for the determination of glyphosate herbicide and its metabolite amino-methyl-phosphonic acid (AMPA) in surface waters to a level of 0.1μg/L, while in sediments and soils to a level of 0.5μg/g with a good linearity in the calibration range of 1-100μg/L. The procedure involves a pre-columnderivatization step with 9-fluorenyl-methyl-chloroformate (FMOC-Cl) yielding highly fluorescent derivatives of the analytes which can be determined by HPLC with fluorescence detection. In the field, levels of glyphosate in surface waters ranges from not detected to 1.0mg/L, while in soils and sediments were from not detected to 6.0mg/kg. For AMPA, the residues in surface waters were between not detected to 2.0mg/L, while in soil and sediment samples were from not detected to 5mg/kg. This variation of glyphosate and AMPA levels depended directly on time of pesticide application and the season.

Uncertainty estimation of water levels for the Mitch flood event in Tegucigalpa

NASA Astrophysics Data System (ADS)

Fuentes Andino, D. C.; Halldin, S.; Lundin, L.; Xu, C.

2012-12-01

Hurricane Mitch in 1998 left a devastating flood in Tegucigalpa, the capital city of Honduras. Simulation of elevated water surfaces provides a good way to understand the hydraulic mechanism of large flood events. In this study the one-dimensional HEC-RAS model for steady flow conditions together with the two-dimensional Lisflood-fp model were used to estimate the water level for the Mitch event in the river reaches at Tegucigalpa. Parameters uncertainty of the model was investigated using the generalized likelihood uncertainty estimation (GLUE) framework. Because of the extremely large magnitude of the Mitch flood, no hydrometric measurements were taken during the event. However, post-event indirect measurements of discharge and observed water levels were obtained in previous works by JICA and USGS. To overcome the problem of lacking direct hydrometric measurement data, uncertainty in the discharge was estimated. Both models could well define the value for channel roughness, though more dispersion resulted from the floodplain value. Analysis of the data interaction showed that there was a tradeoff between discharge at the outlet and floodplain roughness for the 1D model. The estimated discharge range at the outlet of the study area encompassed the value indirectly estimated by JICA, however the indirect method used by the USGS overestimated the value. If behavioral parameter sets can well reproduce water surface levels for past events such as Mitch, more reliable predictions for future events can be expected. The results acquired in this research will provide guidelines to deal with the problem of modeling past floods when no direct data was measured during the event, and to predict future large events taking uncertainty into account. The obtained range of the uncertain flood extension will be an outcome useful for decision makers.

Coliphages as indicators of enteroviruses.

PubMed Central

Stetler, R E

1984-01-01

Coliphages were monitored in conjunction with indicator bacteria and enteroviruses in a drinking-water plant modified to reduce trihalomethane production. Coliphages could be detected in the source water by direct inoculation, and sufficient coliphages were detected in enterovirus concentrates to permit following the coliphage levels through different water treatment processes. The recovery efficiency by different filter types ranged from 1 to 53%. Statistical analysis of the data indicated that enterovirus isolates were better correlated with coliphages than with total coliforms, fecal coliforms, fecal streptococci, or standard plate count organisms. Coliphages were not detected in finished water. PMID:6093694

Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, May 2008

USGS Publications Warehouse

Kinnaman, Sandra L.; Dixon, Joann F.

2008-01-01

This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 2008. Potentiometric contours are based on water-level measurements collected at 567 wells during the period May 6-May 27, near the end of the dry season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours. Measured values of the potentiometric surface ranged from 7 feet below NGVD29 near Fernandina Beach, Florida, to 124 feet above NGVD29 in Polk County, Florida. The average water level of the network in May 2008 was about 1 foot lower than the average in September 2007 following below-average rainfall during the dry season of 2007-08. Seasonal differences in network average water levels generally range from 4 to 6 feet. For 457 wells with previous measurements, May 2008 levels ranged from about 19 feet below to about 11 feet above September 2007 water levels. The average water level of the network in May 2008 was about 1 foot higher than the average in May 2007. For 544 wells with previous measurements, May 2008 levels ranged from about 8 feet below to about 13 feet above May 2007 water levels. Long-term hydrographs of ground-water levels for continuous and periodic wells are available at internet site: http://waterdata.usgs.gov/fl/nwis/gw

CMS-Wave Model: Part 3: Grid Nesting and Application Example for Rhode Island South Shore Regional Sediment Management Study

DTIC Science & Technology

2010-07-01

CDIP 154 (NDBC 44097) in 48-m water depth. Figure 5 shows the extent of the regional bathymetry grid and five nested child grids covering the...directional spectra from the nearest offshore buoy ( CDIP 154). The water level along the ocean boundary is from the Le Provost database. In the

Determination of tributyltin in whole water matrices under the European Water Framework Directive.

PubMed

Richter, Janine; Fettig, Ina; Philipp, Rosemarie; Jakubowski, Norbert; Panne, Ulrich; Fisicaro, Paola; Alasonati, Enrica

2016-08-12

Monitoring of water quality is important to control water pollution. Contamination of the aquatic system has a large effect on human health and the environment. Under the European Water Framework Directive (WFD) 2000/60/EC and the related directive on environmental quality standards (EQS) in the field of water policy 2008/105/EC, the need for sensitive reference methods was highlighted. Since tributyltin (TBT) is one of the WFD listed priority substances a method was developed which is capable to qualify and quantify the pollutant at the required low WFD EQS of 0.2ngL(-1) in whole water bodies, i.e. in non-filtered water samples with dissolved organic carbon and suspended particulate matter. Therefore special attention was paid on the interaction of TBT with the suspended particulate matter and humic substances to obtain a complete representation of the pollution in surface waters. Different water samples were investigated varying the content of organic dissolved and suspended matter. Quantification was performed using species-specific isotope dilution (SSID) and gas chromatography with inductively coupled plasma mass spectrometry (GC-ICP-MS). Different sample treatment strategies were evaluated and compared. The process of internal standard addition was investigated and optimized, hence the equilibrium between internal standards and matrix is of primary importance to perform accurate SSID. Samples spiked at EQS level were analyzed with a recovery between 95 and 105 %. Additionally real surface water samples were investigated and the TBT concentration for the whole water body was determined and compared with conventional routine analysis method. Copyright © 2016 Elsevier B.V. All rights reserved.

Ground-Water Flow Direction, Water Quality, Recharge Sources, and Age, Great Sand Dunes National Monument, South-Central Colorado, 2000-2001

USGS Publications Warehouse

Rupert, Michael G.; Plummer, Niel

2004-01-01

Great Sand Dunes National Monument is located in south-central Colorado along the eastern edge of the San Luis Valley. The Great Sand Dunes National Monument contains the tallest sand dunes in North America; some rise up to750 feet. Important ecological features of the Great Sand Dunes National Monument are palustrine wetlands associated with interdunal ponds and depressions along the western edge of the dune field. The existence and natural maintenance of the dune field and the interdunal ponds are dependent on maintaining ground-water levels at historic elevations. To address these concerns, the U.S. Geological Survey conducted a study, in collaboration with the National Park Service, of ground-water flow direction, water quality, recharge sources, and age at the Great Sand Dunes National Monument. A shallow unconfined aquifer and a deeper confined aquifer are the two principal aquifers at the Great Sand Dunes National Monument. Ground water in the unconfined aquifer is recharged from Medano and Sand Creeks near the Sangre de Cristo Mountain front, flows underneath the main dune field, and discharges to Big and Little Spring Creeks. The percentage of calcium in ground water in the unconfined aquifer decreases and the percentage of sodium increases because of ionic exchange with clay minerals as the ground water flows underneath the dune field. It takes more than 60 years for the ground water to flow from Medano and Sand Creeks to Big and Little Spring Creeks. During this time, ground water in the upper part of the unconfined aquifer is recharged by numerous precipitation events. Evaporation of precipitation during recharge prior to reaching the water table causes enrichment in deuterium (2H) and oxygen-18 (18O) relative to waters that are not evaporated. This recharge from precipitation events causes the apparent ages determined using chlorofluorocarbons and tritium to become younger, because relatively young precipitation water is mixing with older waters derived from Medano and Sand Creeks. Major ion chemistry of water from sites completed in the confined aquifer is different than water from sites completed in the unconfined aquifer, but insufficient data exist to quantify if the two aquifers are hydrologically disconnected. Radiocarbon dating of ground water in the confined aquifer indicates it is about 30,000 years old (plus or minus 3,000 years). The peak of the last major ice advance (Wisconsin) during the ice age occurred about 20,000 years before present; ground water from the confined aquifer is much older than that. Water quality and water levels of the interdunal ponds are not affected by waters from the confined aquifer. Instead, the interdunal ponds are affected directly by fluctuations in the water table of the unconfined aquifer. Any lowering of the water table of the unconfined aquifer would result in an immediate decrease in water levels of the interdunal ponds. The water quality of the interdunal ponds probably results from several factors, including the water quality of the unconfined aquifer, evaporation of the pond water, and biologic activity within the ponds.

On the derivation of specific yield and soil water retention characteristics in peatlands from rainfall, microrelief and water level data - Theory and Practice

NASA Astrophysics Data System (ADS)

Dettmann, Ullrich; Bechtold, Michel

2016-04-01

Water level depth is one of the crucial state variables controlling the biogeochemical processes in peatlands. For flat soil surfaces, water level depth dynamics as response to boundary fluxes are primarily controlled by the water retention characteristics of the soil in and above the range of the water level fluctuations. For changing water levels, the difference of the integrals of two soil moisture profiles (ΔAsoil), of a lower and a upper water level, is equal to the amount of water received or released by the soil. Dividing ΔAsoil by the water level change, results into a variable that is known as specific yield (Sy). For water level changes approaching the soil surface, changes in soil water storage are small due to the thin unsaturated zone that remains. Consequentially, Sy values approach zero with an abrupt transition to 1 in case of inundation. However, on contrary, observed water level rises due to precipitation events at various locations showed increasing Sy values for water level changes at shallow depths (Sy = precipitation/water level change; Logsdon et al., 2010). The increase of Sy values can be attributed in large parts to the influence of the microrelief on water level changes in these wet landscapes that are characterized by a mosaic of inundated and non-inundated areas. Consequentially, water level changes are dampened by partial inundation. In this situation, total Sy is composed of a spatially-integrated below ground and above ground contribution. We provide a general one-dimensional expression that correctly represents the effect of a microrelief on the total Sy. The one-dimensional expression can be applied for any soil hydraulic parameterizations and soil surface elevation frequency distributions. We demonstrate that Sy is influenced by the microrelief not only when surface storage directly contributes to Sy by (partial) inundation but also when water levels are lower than the minimum surface elevation. With the derived one-dimensional expression we developed a novel approach for the in situ determination of soil water retention characteristics that is applicable to shallow groundwater systems. Our approach is built on two assumptions: i) for shallow groundwater systems with medium- to high conductive soils the soil moisture profile is always close to hydrostatic equilibrium and ii) over short time periods differences in total water storage due to lateral fluxes are negligible. Given these assumptions, the height of a water level rise due to a precipitation event mainly depends on the soil water retention characteristics, the precipitation amount, the initial water level depth and, if present, the microrelief. We use this dependency to determine water retention characteristics (van Genuchten parameter) by Bayesian inversion. Our results demonstrate that observations of water level rises, caused by precipitation events, contain sufficient information to constrain the water retention characteristics around two dip wells in a Sphagnum bog to plausible ranges. We discuss the possible biases that come along with our approach and point out the research that is needed to quantify their significance.

Direct screening and confirmation of priority volatile organic pollutants in drinking water.

PubMed

Caro, J; Serrano, A; Gallego, M

2007-01-05

A screening tool was proposed for the rapid detection of eight priority volatile organic pollutants according to European standards in drinking water. The method is based on the direct coupling of a headspace sampler with a mass spectrometer, using a chromatographic column heated to 175 degrees C as an interface. The water sample was subjected to the headspace extraction process and the volatile fraction was introduced directly into the mass spectrometer, without prior chromatographic separation, achieving low detection limits (0.6-1.2 ng/ml) for all compounds. The mass spectrum resulting from the simultaneous ionization and fragmentation of the mixture of molecules constitutes the volatile profile of each sample. An appropriate chemometric treatment of these signals permitted them to be classified, on the basis of their volatile composition, as contaminated or uncontaminated with respect to the legally established concentration levels for these compounds in drinking water, and providing no false negatives. A conventional confirmation method was carried out to analyze positive water samples by using the same instrumental setup as in the screening method, but using an appropriate temperature program in the chromatographic column to separate, identify and quantify each analyte.

Availability of streamflow for recharge of the basal aquifer in the Pearl Harbor area, Hawaii

USGS Publications Warehouse

Hirashima, George Tokusuke

1971-01-01

The Pearl Harbor area is underlain by an extensive basal aquifer that contains large supplies of fresh water. Because of the presence of a cap rock composed of sedimentary material that is less permeable than the basaltic lava of the basal aquifer, seaward movement of ground water is retarded. The cap rock causes the basal water to stand at a high level; thus, the lens of fresh water that floats on sea water is thick. Discharge from the basal ground-water body, which includes pumpage from wells and shafts, averaged 250 million gallons per day during 1931-65. Because the water level in the basal aquifer did not decline progressively, recharge to the ground-water body must have been approximately equal to discharge. Although pumping for agricultural use has decreased since 1931, net ground-water discharge has increased because of a large increase in pumping for urban use. Substitution of ground water for surface water in the irrigation of sugarcane has also contributed to a net increase in ground-water discharge. The development of Mililani Town will further increase discharge. The increase in ground-water discharge may cause an increase in chloride content of the water pumped from wells near the shore of Pearl Harbor unless the increased discharge is balanced by increased recharge to the local aquifer. The aquifer is recharged by direct infiltration and deep percolation of rain, principally in the high forested area, by infiltration and percolation of irrigation water applied in excess of plant requirements, by seepage of water through streambeds, and possibly by ground-water inflow from outside the area. Recharge is greatest in the uplands, where rainfall is heavy and where much infiltration takes place before rainwater collects in the middle and lower reaches of stream channels. Once water collects in and saturates the alluvium of stream channels, additional inflow to the streams will flow out to sea, only slightly decreased by seepage. Average annual direct runoff from the 90-square-mile Pearl Harbor area is 47.27 million gallons per day, or 11.1 inches; this is 13.3 percent of the average annual rainfall (83.3 in.) over the area. Average annual direct runoff in streams at the 800- and 400-foot altitudes is 29 and 38 million gallons per day, respectively. Kipapa Stream has the largest average annual direct runoff at those altitudes--6 and 9 million gallons per day, respectively. Because streams are flashy and have a wide range in discharge, only 60 percent of the average annual runoff can be economically diverted through ditches to recharge areas. The diversion may be increased slightly if reservoirs are used in conjunction with ditches to temporarily detain flows in excess of ditch capacity. The planned irrigation use of some of the perennial flow available in Waikele Stream near sea level will decrease pumping from and increase recharge to the basal aquifer. Suspended-sediment load is mainly silt and clay, and it increases rapidly with increased discharge. Thus, the use of streamflow for artificial recharge poses problems. High flows must be used if recharge is to be effective, but flows must not be so high as to cause clogging of recharge facilities with sediment or woodland debris. Practical tests are needed to determine the advantages and disadvantages of different types of recharge structures, such as a reservoir or basin, large-diameter deep shafts, deep wells, or combinations of all these structures.

Potentiometric Surface of the Aquia Aquifer in Southern Maryland, September 1999

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Wheeler, Judith C.

2001-01-01

This report presents a map showing the potentiometric surface of the Aquia aquifer in the Aquia Formation of Paleocene age in Southern Maryland during September 1999. The map is based on water-level measurements in 85 wells. The potentiometric surface was above sea level near the northern boundary and outcrop area of the aquifer in a topographically high area of Anne Arundel County, and was below sea level in the remainder of the study area. The hydraulic gradient was directed southeastward toward an extensive cone of depression around well fields at Lexington Park and Solomons Island. Ground-water levels were more than 80 feet below sea level in a 100-square-mile area surrounding the deepest part of the cone of depression. A cone of depression formed in northern Calvert County due to pumpage at Chesapeake Beach and North Beach. The water level has declined to 43 feet below sea level in this area. The lowest measurement was 164 feet below sea level in a well near the center of the cone of depression at Lexington Park.

Defining restoration targets for water depth and salinity in wind-dominated Spartina patens (Ait.) Muhl. coastal marshes

USGS Publications Warehouse

Nyman, J.A.; LaPeyre, Megan K.; Caldwell, Andral W.; Piazza, Sarai C.; Thom, C.; Winslow, C.

2009-01-01

Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable.

Defining restoration targets for water depth and salinity in wind-dominated Spartina patens (Ait.) Muhl. coastal marshes

USGS Publications Warehouse

Nyman, J.A.; La Peyre, M.K.; Caldwell, A.; Piazza, S.; Thom, C.; Winslow, C.

2009-01-01

Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable. ?? 2009 Elsevier B.V.

Hydrologic conditions, recharge, and baseline water quality of the surficial aquifer system at Jekyll Island, Georgia, 2012-13

USGS Publications Warehouse

Gordon, Debbie W.; Torak, Lynn J.

2016-03-08

Groundwater levels and specific-conductance measurements showed the dependence of freshwater resources on rainfall to recharge the water-table zone of the surficial aquifer system and to influence groundwater flow on Jekyll Island. The unseasonably dry conditions during November 2012 to April 2013 induced saline water infiltration to the water-table zone from the marshland separating the Jekyll River from the island. A strong correlation (R2 = 0.97) of specific conductance to chloride concentration in water samples from wells installed in the water-table zone provided support for the determination of seasonal directions of groundwater flow by confirming salinity changes in the water-table zone. Unseasonably wet conditions during the late spring to August caused groundwater-flow reversals in some areas. The high dependence of the water-table zone in the surficial aquifer system on precipitation to replenish the aquifer with freshwater underscored the importance of monitoring groundwater levels, water quality, and water use to identify aquifer-discharge conditions that have the potential to promote seawater encroachment and degrade freshwater resources on Jekyll Island.

Simulated Effects of Projected 2010 Withdrawals on Ground-Water Flow and Water Levels in the New Jersey Coastal Plain - A Task of the New Jersey Water Supply Plan, 2006 Revision

USGS Publications Warehouse

Gordon, Alison D.

2007-01-01

A ground-water flow model previously developed as part of a Regional Aquifer System Analysis (RASA) of the New Jersey Coastal Plain was used to simulate ground-water flow in eight major confined aquifers to help evaluate ground-water resources in support of the New Jersey Department of Environmental Protection's revision of the New Jersey State Water Supply Plan. This model was calibrated to 1998 steady-state and transient conditions. Withdrawals at wells in operation in 1998 were varied in three scenarios to evaluate their effects on flow directions, water levels, and water budgets in the confined aquifers. The scenarios used to predict changes in pumpage from 1998 to 2010 were based on (1) a continuation of 1990-99 trends in water use, (2) public-supply withdrawals estimated from county population projections, and (3) restricted withdrawals in Water-Supply Critical Areas. Total withdrawals in these three scenarios were approximately 366, 362, and 355 million gallons per day, respectively. The results of these simulations are used by New Jersey water-management officials to help address water-supply concerns for the State. In the revision of the New Jersey State Water Supply Plan, the eight major confined aquifers of the New Jersey Coastal Plain and their outcrop areas are divided into 41 hydrologic budget areas (HBAs). Simulation results were used to assess the effects of changing ground-water withdrawals on water levels and the flow budgets in each budget area. Simulation results for each scenario were compared with 1998 (baseline) simulated water levels and flow budgets. The 41 hydrologic budget areas are in areas of large ground-water withdrawals, water-level declines, and (or) saltwater-intrusion potential. Their boundaries are based on various hydrologic, geohydrologic, and withdrawal conditions, such as aquifer extent, location of the 250-milligram-per-liter isochlor, aquifer outcrop area, and ground-water divides. The budget areas include primarily the onshore, freshwater portions of the aquifers. A budget analysis was done for each of the hydrologic budget areas for each scenario. Ground-water withdrawals, leakage to streams, net leakage to overlying and underlying aquifers, lateral flow to adjacent budget areas, and the flow direction at the 250-milligram-per-liter isochlor were evaluated. Although three different methods were applied to predict future pumping rates, the simulated water levels for scenarios 1 and 2 were generally within 2 feet of each other in most areas in the confined aquifers, but differences of more than 2 feet occurred locally. Differences in values of flow-budget components between scenarios 1 and 2 as a percentage change from 1998 values were generally within 2 percent in most hydrologic budget areas, but values of some budget components in some hydrologic budget areas differed by more than 2 percent. Simulated water levels recovered as much as 4 feet more in northeastern Camden and northwestern Burlington Counties in the Lower Potomac-Raritan-Magothy aquifer, and as much as 3 feet more in the same area in the Upper and Middle Potomac-Raritan-Magothy aquifers when pumpage restrictions were imposed in Critical Area 2 (scenario 3). In the Wenonah-Mount-Laurel aquifer, water levels declined continually in Monmouth County (HBA 8) downdip from the outcrop (in Critical Area 1) from 1988 to 2010 in all three scenarios, although most of the water levels farther downdip from this area in Critical Area 1 are still recovering because of mandated reductions in pumpage in the 1990s. In the Englishtown aquifer system, water levels declined continually in small areas in HBA 13 in central Monmouth County (in Critical Area 1) and in western Monmouth County downdip from the outcrop from 1988 to 2010 in all three scenarios, although most of the water levels farther downdip from this area are still recovering because of the mandated reductions in pumpage. In the Upper Potomac-Raritan-Magothy aquif

EU Water Framework Directive and Stockholm Convention: can we reach the targets for priority substances and persistent organic pollutants?

PubMed

Fuerhacker, Maria

2009-08-01

Water is a renewable resource and acceptable quality is important for human health, ecological and economic reasons, but human activity can cause great damage to the natural aquatic environment. Managing the water cycle in a sustainable way is the key to protect natural resources and human health. On a global level, the microbiological contamination of water sources is a major problem in connection with poverty and the United Nations Millennium Development Declaration is an important initiative to handle this problem. In terms of environmental health, persistent organic pollutants (POPs) circulate globally; as they travel long distances, they are found in remote areas far from their original source of application and can cause damage wherever they move to. On a global scale, United Nations Environmental Programme (UNEP) issued the Stockholm Convention to reduce POPs; in the European Union (EU), one intention of the Water Framework Directive (WFD) is to reach the good chemical status of waters; beside these regulations, there are other directives in support of these goals. The aim of this paper is to discuss whether the Stockholm Convention and the WFD allows meeting the targets of protection of human and environmental health, which are established in the different directives and how could we approach the targets. The aims and scopes of different directives are compiled and compared with the actual quality of water, different approaches of standard settings are compared and potential treatment options are discussed. Under the Stockholm Convention on POPs, which came into force in May 2004, governments are required to develop a National Implementation Plan (NIP) setting out how they will address their obligations under the convention and how they will take measures to eliminate or reduce the release of POPs into the environment by the use of best available techniques (BAT) and application of best environmental practices (BEP). On a European level, the WFD has been in place as the main European legislation to protect our water resources and the water environment of Europe since 2000. It requires managing river basins so that the quality and quantity of water does not affect the ecological services of any specific water body. Nevertheless, the goals of other directives as for drinking water, bathing water and urban wastewater treatment are not yet harmonised mainly concerning microbiological, priority substances and priority hazardous substances (PS/PHS) contamination. Following the detection of substances, a risk assessment with sound effect data needs to be performed also for regulatory decisions and priorisation of measures to remove emerging contaminants. Beside personal care products and industrial contaminants, faecal pollution of recreational waters is one of the major hazards facing users, although microbial contamination from other sources as well as chemical and physical aspects also affects the suitability of water for recreation. As in arid and semiarid areas, wastewater is considered for irrigation with regulatory needs of hygienic and chemical parameters-health-based targets-to avoid the contamination of crops and food. In surface waters, currently, the relationships between physical and chemical properties and the biological state of surface waters were quite well-understood to enable the management of catchments and rivers to achieve ecological quality. Nevertheless, more work is needed to find out the actual impact of the regulations for single chemicals and complex mixtures, in terms of environmental quality standards to achieve a 'good chemical status', on the good biological status. In a next step after the adoption of the list of PS/PHS substances, which also includes the POPs, the Urban Wastewater Treatment Directive (UWWTD) needs to be adjusted and existing or new treatment options (BATs) should comply with the new requirements of the different directives. Relevant substances threaten human health and the environment by new effects such as CMR, endocrine-disrupting effects or neurotoxicity which are not yet considered in an adequate way by assessment methods and regulatory standards and the application of abatement technologies. The Registration, Evaluation, Authorisation and Restriction of Chemicals helps to control the sources, but WFD, the Stockholm Convention and UWWTD need to be harmonised and a rolling revision process should react on new developments. Finally, to answer the question if the Stockholm Convention and the WFD (2000/60/EC) could reach the target-I would state that they provide a very valuable frame to approach the targets, but there is still way to go to reach them on an EU level and on a global scale, also under the aspects of the Stockholm Convention and the Millennium Development Goals. The compilation of the goals of different regulations and combined actions will save a lot of administrative efforts and money.

Inter-City Virtual Water Transfers Within a Large Metropolitan Area: A Case Study of the Phoenix Metropolitan Area in the United States

NASA Astrophysics Data System (ADS)

Rushforth, R.; Ruddell, B. L.

2014-12-01

Water footprints have been proposed as potential sustainability indicators, but these analyses have thus far focused at the country-level or regional scale. However, for many countries, especially the United States, the most relevant level of water decision-making is the city. For water footprinting to inform urban sustainability, the boundaries for analysis must match the relevant boundaries for decision-making and economic development. Initial studies into city-level water footprints have provided insight into how large cities across the globe—Delhi, Lagos, Berlin, Beijing, York—create virtual water trade linkages with distant hinterlands. This study hypothesizes that for large cities the most direct and manageable virtual water flows exist at the metropolitan area scale and thus should provide the most policy-relevant information. This study represents an initial attempt at quantifying intra-metropolitan area virtual water flows. A modified commodity-by-industry input-output model was used to determine virtual water flows destined to, occurring within, and emanating from the Phoenix metropolitan area (PMA). Virtual water flows to and from the PMA were calculated for each PMA city using water consumption data as well as economic and industry statistics. Intra-PMA virtual water trade was determined using county-level traffic flow data, water consumption data, and economic and industry statistics. The findings show that there are archetypal cities within metropolitan areas and that each type of city has a distinct water footprint profile that is related to the value added economic processes occuring within their boundaries. These findings can be used to inform local water managers about the resilience of outsourced water supplies.

Colors of Alien Worlds from Direct Imaging Exoplanet Missions

NASA Astrophysics Data System (ADS)

Hu, Renyu

2015-08-01

Future direct-imaging exoplanet missions such as WFIRST/AFTA, Exo-C, and Exo-S will measure the reflectivity of exoplanets at visible wavelengths. Most of the exoplanets to be observed will be located further away from their parent stars than is Earth from the Sun. These “cold” exoplanets have atmospheric environments conducive for the formation of water and/or ammonia clouds, like Jupiter in the Solar System. I find the mixing ratio of methane and the pressure level of the uppermost cloud deck on these planets can be uniquely determined from their reflection spectra, with moderate spectral resolution, if the cloud deck is between 0.6 and 1.5 bars. The existence of this unique solution is useful for exoplanet direct imaging missions for several reasons. First, the weak bands and strong bands of methane enable the measurement of the methane mixing ratio and the cloud pressure, although an overlying haze layer can bias the estimate of the latter. Second, the cloud pressure, once derived, yields an important constraint on the internal heat flux from the planet, and thus indicating its thermal evolution. Third, water worlds having H2O-dominated atmospheres are likely to have water clouds located higher than the 10-3 bar pressure level, and muted spectral absorption features. These planets would occupy a confined phase space in the color-color diagrams, likely distinguishable from H2-rich giant exoplanets by broadband observations. Therefore, direct-imaging exoplanet missions may offer the capability to broadly distinguish H2-rich giant exoplanets versus H2O-rich super-Earth exoplanets, and to detect ammonia and/or water clouds and methane gas in their atmospheres.

Modelling the photochemical attenuation pathways of the fibrate drug gemfibrozil in surface waters.

PubMed

Fabbri, Debora; Maurino, Valter; Minella, Marco; Minero, Claudio; Vione, Davide

2017-03-01

Gemfibrozil (GFZ) is a relatively persistent pollutant in surface-water environments and it is rather recalcitrant to biological degradation. The GFZ photochemical lifetimes are relatively short in shallow waters with low levels of dissolved organic carbon (DOC), but they can reach the month-year range in deep and high-DOC waters. The main reason is that GFZ undergoes negligible reaction with singlet oxygen or degradation sensitised by the triplet states of chromophoric dissolved organic matter, which are the usually prevalent photochemical pathways in deep and high-DOC sunlit waters. Nitrate and nitrite scarcely affect the overall GFZ lifetimes, but they can shift photodegradation from direct photolysis to the OH process. These two pathways are the main GFZ phototransformation routes, with the direct photolysis prevailing in shallow environments during summer. Under these conditions the GFZ photochemical lifetimes are also shorter and the environmental significance of photodegradation correspondingly higher. The direct photolysis of GFZ under UVB irradiation yielded several transformation intermediates deriving from oxidation or cleavage of the aliphatic lateral chain. A quinone derivative (2,5-dimethyl-1,4-benzoquinone), a likely oxidation product of the transformation intermediate 2,5-dimethylphenol, is expected to be the most acutely and chronically toxic compound arising from GFZ direct photolysis. Interestingly, literature evidence suggests that the same toxic intermediate would be formed upon OH reaction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ground-Water Levels and Water-Quality Data for Wells in the Crumpton Creek Area near Arnold Air Force Base, Tennessee, November 2001 to January 2002

USGS Publications Warehouse

Williams, Shannon D.

2003-01-01

From November 2001 to January 2002, a study of the ground-water resources in the Crumpton Creek area of Middle Tennessee was conducted to determine whether volatile organic compounds (VOCs) from Arnold Air Force Base (AAFB) have affected local private water supplies and to advance understanding of the ground-water-flow system in this area. VOC samples were collected from private wells that were not included in previous sampling efforts conducted in the Crumpton Creek area near AAFB. Ground-water-flow directions were investigated by measuring water levels in wells and constructing a potentiometric-surface map of the Manchester aquifer in the study area. Data were collected from a total of 68 private wells, 82 monitoring wells, and 1 cave during the period of study. Ground-water levels were determined for 42 of the private wells and for all 82 monitoring wells. Of the 82 monitoring wells, 81 withdraw water from the Manchester aquifer and 1 well withdraws water from the overlying shallow aquifer. The Manchester aquifer wells range in depth from 20 to 150 feet. Water-level altitudes for the Manchester aquifer ranged from 956 to 1,064 feet above the National Geodetic Vertical Datum of 1929. Water levels ranged from approximately 6 feet above land surface to 94 feet below land surface. Water-quality samples were collected from all 68 private wells, 8 of the monitoring wells, and the 1 cave. Of the 55 VOCs analyzed, 42 were not detected. Thirteen VOCs were detected; however, only tetrachloroethylene (PCE), methylene chloride, and toluene were detected at concentrations equal to or above reporting levels for the analytical method used. PCE was detected in water samples from 15 private wells and was the only VOC that exceeded drinking water maximum contaminant levels for public water systems. PCE concentrations in samples from five of the wells were below the reporting level and ranged from estimated concentrations of 0.46 to 0.80 microgram per liter (?g/L). Samples from 10 wells contained concentrations equal to or greater than the analytical reporting level of 1 ?g/L for PCE. Samples from one of these wells contained PCE concentrations (12 ?g/L and 11 ?g/L) exceeding the drinking water maximum contaminant level of 5 ?g/L for PCE. The spatial distribution of PCE detections and the relative concentrations of PCE and trichloroethylene suggest that the PCE detections are associated with a small and localized ground-water contamination plume unrelated to AAFB ground-water contamination.

Topsoil structure stability in a restored floodplain: Impacts of fluctuating water levels, soil parameters and ecosystem engineers.

PubMed

Schomburg, A; Schilling, O S; Guenat, C; Schirmer, M; Le Bayon, R C; Brunner, P

2018-10-15

Ecosystem services provided by floodplains are strongly controlled by the structural stability of soils. The development of a stable structure in floodplain soils is affected by a complex and poorly understood interplay of hydrological, physico-chemical and biological processes. This paper aims at analysing relations between fluctuating groundwater levels, soil physico-chemical and biological parameters on soil structure stability in a restored floodplain. Water level fluctuations in the soil are modelled using a numerical surface-water-groundwater flow model and correlated to soil physico-chemical parameters and abundances of plants and earthworms. Causal relations and multiple interactions between the investigated parameters are tested through structural equation modelling (SEM). Fluctuating water levels in the soil did not directly affect the topsoil structure stability, but indirectly through affecting plant roots and soil parameters that in turn determine topsoil structure stability. These relations remain significant for mean annual days of complete and partial (>25%) water saturation. Ecosystem functioning of a restored floodplain might already be affected by the fluctuation of groundwater levels alone, and not only through complete flooding by surface water during a flood period. Surprisingly, abundances of earthworms did not show any relation to other variables in the SEM. These findings emphasise that earthworms have efficiently adapted to periodic stress and harsh environmental conditions. Variability of the topsoil structure stability is thus stronger driven by the influence of fluctuating water levels on plants than by the abundance of earthworms. This knowledge about the functional network of soil engineering organisms, soil parameters and fluctuating water levels and how they affect soil structural stability is of fundamental importance to define management strategies of near-natural or restored floodplains in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

Simulated water sources and effects of pumping on surface and ground water, Sagamore and Monomoy flow lenses, Cape Cod, Massachusetts

USGS Publications Warehouse

Walter, Donald A.; Whealan, Ann T.

2005-01-01

The sandy sediments underlying Cape Cod, Massachusetts, compose an important aquifer that is the sole source of water for a region undergoing rapid development. Population increases and urbanization on Cape Cod lead to two primary environmental effects that relate directly to water supply: (1) adverse effects of land use on the quality of water in the aquifer and (2) increases in pumping that can adversely affect environmentally sensitive surface waters, such as ponds and streams. These considerations are particularly important on the Sagamore and Monomoy flow lenses, which underlie the largest and most populous areas on Cape Cod. Numerical models of the two flow lenses were developed to simulate ground-water-flow conditions in the aquifer and to (1) delineate areas at the water table contributing water to wells and (2) estimate the effects of pumping and natural changes in recharge on surface waters. About 350 million gallons per day (Mgal/d) of water recharges the aquifer at the water table in this area; most water (about 65 percent) discharges at the coast and most of the remaining water (about 28 percent) discharges into streams. A total of about 24.9 Mgal/d, or about 7 percent, of water in the aquifer is withdrawn for water supply; most pumped water is returned to the hydrologic system as return flow creating a state of near mass balance in the aquifer. Areas at the water table that contribute water directly to production wells total about 17 square miles; some water (about 10 percent) pumped from the wells flows through ponds prior to reaching the wells. Current (2003) steady-state pumping reduces simulated ground-water levels in some areas by more than 4 feet; projected (2020) pumping may reduce water levels by an additional 3 feet or more in these same areas. Current (2003) and future (2020) pumping reduces total streamflow by about 4 and 9 cubic feet per second (ft3/s), corresponding to about 5 percent and 9 percent, respectively, of total streamflow. Natural recharge varies with time, over both monthly and multiyear time scales. Monthly changes in recharge cause pond levels to vary between 1 and 2 feet in an average year; annual changes in recharge, which can be much larger than monthly variations, can cause pond levels to vary by more than 10 feet in some areas over a period of years. Streamflow, which also changes in response to changes in recharge, varies by a factor of two over an average year and can vary more over multiyear periods. On average, monthly pumping ranges from 15.8 Mgal/d in March to 45.3 Mgal/d in August. Pumping and the distribution of return flow can seasonally affect the hydrologic system by lowering ground-water and pond levels and by depleting streamflows, particularly in the summer months. Maximum drawdowns in March and August exceed 3 feet and 6 feet, respectively, for current (2003) pumping. Simulated drawdowns from projected (2020) pumping, relative to water levels representing 2003 pumping conditions, exceed 2 feet in March and 5 feet in August. Current (2003) and future (2020) pumping can decrease pond levels in some areas by more than 3 feet; drawdown generally is largest during the month of August of an average year. Over multiyear periods, seasonal pumping can lower pond levels in some areas by more than 4 feet; the effects of seasonal pumping are largest during periods of reduced recharge. Monthly streamflow depletion varies in individual streams but can exceed 2 ft3/s in some streams. The combined effects of seasonal pumping and drought can reduce pond levels by more than 10 feet below average levels. Water levels in Mary Dunn Pond, which is in an area of large current and projected pumping, are predicted (2020) to decline during drought conditions by about 10.6 feet: about 6.9 feet from lower recharge, about 2.3 feet from current (2003) pumping, and about 1.4 feet from additional future (2020) pumping. The results indicate that pumping generally does not cause substantial

Temporal changes in the configuration of the water table in the vicinity of the management systems evaluation area site, central Nebraska

USGS Publications Warehouse

Kilpatrick, John M.

1996-01-01

To improve understanding of the hydrologic characteristics of the shallow aquifer in the vicinity of the Management Systems Evaluation Area site near Shelton, Nebraska, water levels were measured in approximately 130 observation wells in both June and September 1991. Two water-table maps and a water-level-change map were drawn on the basis of these measurements. In addition, historical data from U.S. Geological Survey computer files and published reports were used to determine the approximate configuration of the water table in 1931 and to draw one short-term and two-long term water- level hydrographs. Comparison of the three water- table maps indicates general similarities. The average horizontal hydraulic gradient in the shallow aquifer is about 7.5 feet per mile, and the flow direction is to the east-northeast. The water table declined 2 to 10 feet between June and September 1991, with the greatest decline occurring in a wedge-shaped area south of the Wood River and north of the Platte River. The 1991 water-table configurations appear to indicate that the aquifer either was discharging to the Platte River in this reach or there was little flow between the river and the aquifer. Comparison of the 1931 and 1991 water-table maps indicates that, except for short-term variations, the water-table configuration changed little during this 61-year period. Two long-term water-level hydrographs confirm this conclusion, indicating that the shallow aquifer in this area has been in long-term, dynamic equilibrium.

A continental-scale hydrology and water quality model for Europe: Calibration and uncertainty of a high-resolution large-scale SWAT model

NASA Astrophysics Data System (ADS)

Abbaspour, K. C.; Rouholahnejad, E.; Vaghefi, S.; Srinivasan, R.; Yang, H.; Kløve, B.

2015-05-01

A combination of driving forces are increasing pressure on local, national, and regional water supplies needed for irrigation, energy production, industrial uses, domestic purposes, and the environment. In many parts of Europe groundwater quantity, and in particular quality, have come under sever degradation and water levels have decreased resulting in negative environmental impacts. Rapid improvements in the economy of the eastern European block of countries and uncertainties with regard to freshwater availability create challenges for water managers. At the same time, climate change adds a new level of uncertainty with regard to freshwater supplies. In this research we build and calibrate an integrated hydrological model of Europe using the Soil and Water Assessment Tool (SWAT) program. Different components of water resources are simulated and crop yield and water quality are considered at the Hydrological Response Unit (HRU) level. The water resources are quantified at subbasin level with monthly time intervals. Leaching of nitrate into groundwater is also simulated at a finer spatial level (HRU). The use of large-scale, high-resolution water resources models enables consistent and comprehensive examination of integrated system behavior through physically-based, data-driven simulation. In this article we discuss issues with data availability, calibration of large-scale distributed models, and outline procedures for model calibration and uncertainty analysis. The calibrated model and results provide information support to the European Water Framework Directive and lay the basis for further assessment of the impact of climate change on water availability and quality. The approach and methods developed are general and can be applied to any large region around the world.

Climatic and hydrologic influences on wading bird foraging patterns in Everglades National Park

NASA Astrophysics Data System (ADS)

Kwon, H.; Lall, U.; Engel, V.

2007-12-01

A goal of the Everglades National Park (ENP) restoration project is to ensure that the ecological health of the ENP improves as a direct result of management activities. Achieving hydrologic targets through the proper timing and amount of releases from control structures is a first step in the management process. Significant climate and weather variations in the region influence the ability to make releases and also determine the ecological outcomes. An assessment of the relative impact of climate variations and water releases to ENP in determining ecological outcomes is consequently a key to the evaluation of the success or failure of any restoration plan. Seasonal water depths in ENP depend on managed surface water releases from control structures and on direct rainfall. Here we link wading bird foraging patterns - a fundamental aspect of Everglades' ecology - to hydrologic management and climate variability in the National Park. Our objective is multifold. First, we relate the water levels at P33 and Shark Slough to the synoptic hydrologic conditions. Second, we develop a statistical model relating water levels at a station in central Shark Slough (P33) to wading birds foraging patterns throughout ENP. We attempt to apply a Hierarchical Bayesian scheme to a time series of wading bird to provide an uncertainty distribution of the population over specified time periods given hydrologic condition. Third, we develop a set of hydrologic index derived by recorded water level at P33 for a use of the statistical model of wading birds as an input. Our study will focus on great egret and white ibis that are major species among wading birds in the ENP. The great egret and white ibis prediction predicted by the model using the proposed predictors exhibits strong correlation with the observed streamflow, with an correlation 0.8.

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.

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.

Use of Microgravity to Assess the Effects of El Nino on Ground-Water Storage in Southern Arizona

USGS Publications Warehouse

Parker, John T.C.; Pool, Donald R.

1998-01-01

The availability of ground water is of extreme importance in areas, such as southern Arizona, where it is the main supply for agricultural, industrial, or domestic purposes. Where ground-water use exceeds recharge, monitoring is critical for managing water supplies. Typically, monitoring has been done by measuring water levels in wells; however, this technique only partially describes ground-water conditions in a basin. A new application of geophysical technology is enabling U.S. Geological Survey (USGS) scientists to measure changes in the amount of water in an aquifer using a network of microgravity stations. This technique enables a direct measurement of ground-water depletion and recharge. In Tucson, Arizona, residents have relied solely upon ground water for most of their needs since the 19th century. Water levels in some wells in the Tucson area have declined more than 200 ft in the past 50 years. Similar drops in water levels have occurred elsewhere in Arizona. In response to the overdrafting of ground water, the State of Arizona passed legislation designed to attain 'safe yield,' which is defined as a balance between ground-water withdrawals and annual recharge of aquifers. To monitor progress in complying with the legislation, ground-water withdrawals are measured and estimated, and annual recharge is estimated. The Tucson Basin and Avra Valley are two ground-water basins that form the Tucson Active Management Area (TAMA), which by State statute must attain 'safe yield' by the year 2025.

A new classification scheme of European cold-water coral habitats: Implications for ecosystem-based management of the deep sea

NASA Astrophysics Data System (ADS)

Davies, J. S.; Guillaumont, B.; Tempera, F.; Vertino, A.; Beuck, L.; Ólafsdóttir, S. H.; Smith, C. J.; Fosså, J. H.; van den Beld, I. M. J.; Savini, A.; Rengstorf, A.; Bayle, C.; Bourillet, J.-F.; Arnaud-Haond, S.; Grehan, A.

2017-11-01

Cold-water corals (CWC) can form complex structures which provide refuge, nursery grounds and physical support for a diversity of other living organisms. However, irrespectively from such ecological significance, CWCs are still vulnerable to human pressures such as fishing, pollution, ocean acidification and global warming Providing coherent and representative conservation of vulnerable marine ecosystems including CWCs is one of the aims of the Marine Protected Areas networks being implemented across European seas and oceans under the EC Habitats Directive, the Marine Strategy Framework Directive and the OSPAR Convention. In order to adequately represent ecosystem diversity, these initiatives require a standardised habitat classification that organises the variety of biological assemblages and provides consistent and functional criteria to map them across European Seas. One such classification system, EUNIS, enables a broad level classification of the deep sea based on abiotic and geomorphological features. More detailed lower biotope-related levels are currently under-developed, particularly with regards to deep-water habitats (>200 m depth). This paper proposes a hierarchical CWC biotope classification scheme that could be incorporated by existing classification schemes such as EUNIS. The scheme was developed within the EU FP7 project CoralFISH to capture the variability of CWC habitats identified using a wealth of seafloor imagery datasets from across the Northeast Atlantic and Mediterranean. Depending on the resolution of the imagery being interpreted, this hierarchical scheme allows data to be recorded from broad CWC biotope categories down to detailed taxonomy-based levels, thereby providing a flexible yet valuable information level for management. The CWC biotope classification scheme identifies 81 biotopes and highlights the limitations of the classification framework and guidance provided by EUNIS, the EC Habitats Directive, OSPAR and FAO; which largely underrepresent CWC habitats.

APEX (Aqueous Photochemistry of Environmentally occurring Xenobiotics): a free software tool to predict the kinetics of photochemical processes in surface waters.

PubMed

Bodrato, Marco; Vione, Davide

2014-04-01

The APEX software predicts the photochemical transformation kinetics of xenobiotics in surface waters as a function of: photoreactivity parameters (direct photolysis quantum yield and second-order reaction rate constants with transient species, namely ˙OH, CO₃(-)˙, (1)O₂ and the triplet states of chromophoric dissolved organic matter, (3)CDOM*), water chemistry (nitrate, nitrite, bicarbonate, carbonate, bromide and dissolved organic carbon, DOC), and water depth (more specifically, the optical path length of sunlight in water). It applies to well-mixed surface water layers, including the epilimnion of stratified lakes, and the output data are average values over the considered water column. Based on intermediate formation yields from the parent compound via the different photochemical pathways, the software can also predict intermediate formation kinetics and overall yield. APEX is based on a photochemical model that has been validated against available field data of pollutant phototransformation, with good agreement between model predictions and field results. The APEX software makes allowance for different levels of knowledge of a photochemical system. For instance, the absorption spectrum of surface water can be used if known, or otherwise it can be modelled from the values of DOC. Also the direct photolysis quantum yield can be entered as a detailed wavelength trend, as a single value (constant or average), or it can be defined as a variable if unknown. APEX is based on the free software Octave. Additional applications are provided within APEX to assess the σ-level uncertainty of the results and the seasonal trend of photochemical processes.

Experimental design for TBT quantification by isotope dilution SPE-GC-ICP-MS under the European water framework directive.

PubMed

Alasonati, Enrica; Fabbri, Barbara; Fettig, Ina; Yardin, Catherine; Del Castillo Busto, Maria Estela; Richter, Janine; Philipp, Rosemarie; Fisicaro, Paola

2015-03-01

In Europe the maximum allowable concentration for tributyltin (TBT) compounds in surface water has been regulated by the water framework directive (WFD) and daughter directive that impose a limit of 0.2 ng L(-1) in whole water (as tributyltin cation). Despite the large number of different methodologies for the quantification of organotin species developed in the last two decades, standardised analytical methods at required concentration level do not exist. TBT quantification at picogram level requires efficient and accurate sample preparation and preconcentration, and maximum care to avoid blank contamination. To meet the WFD requirement, a method for the quantification of TBT in mineral water at environmental quality standard (EQS) level, based on solid phase extraction (SPE), was developed and optimised. The quantification was done using species-specific isotope dilution (SSID) followed by gas chromatography (GC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The analytical process was optimised using a design of experiment (DOE) based on a factorial fractionary plan. The DOE allowed to evaluate 3 qualitative factors (type of stationary phase and eluent, phase mass and eluent volume, pH and analyte ethylation procedure) for a total of 13 levels studied, and a sample volume in the range of 250-1000 mL. Four different models fitting the results were defined and evaluated with statistic tools: one of them was selected and optimised to find the best procedural conditions. C18 phase was found to be the best stationary phase for SPE experiments. The 4 solvents tested with C18, the pH and ethylation conditions, the mass of the phases, the volume of the eluents and the sample volume can all be optimal, but depending on their respective combination. For that reason, the equation of the model conceived in this work is a useful decisional tool for the planning of experiments, because it can be applied to predict the TBT mass fraction recovery when the experimental conditions are drawn. This work shows that SPE is a convenient technique for TBT pre-concentration at pico-trace levels and a robust approach: in fact (i) number of different experimental conditions led to satisfactory results and (ii) the participation of two institutes to the experimental work did not impact the developed model. Copyright © 2014 Elsevier B.V. All rights reserved.

Milk protein composition and stability changes affected by iron in water sources.

PubMed

Wang, Aili; Duncan, Susan E; Knowlton, Katharine F; Ray, William K; Dietrich, Andrea M

2016-06-01

Water makes up more than 80% of the total weight of milk. However, the influence of water chemistry on the milk proteome has not been extensively studied. The objective was to evaluate interaction of water-sourced iron (low, medium, and high levels) on milk proteome and implications on milk oxidative state and mineral content. Protein composition, oxidative stability, and mineral composition of milk were investigated under conditions of iron ingestion through bovine drinking water (infused) as well as direct iron addition to commercial milk in 2 studies. Four ruminally cannulated cows each received aqueous infusions (based on water consumption of 100L) of 0, 2, 5, and 12.5mg/L Fe(2+) as ferrous lactate, resulting in doses of 0, 200, 500 or 1,250mg of Fe/d, in a 4×4Latin square design for a 14-d period. For comparison, ferrous sulfate solution was directly added into commercial retail milk at the same concentrations: control (0mg of Fe/L), low (2mg of Fe/L), medium (5mg of Fe/L), and high (12.5mg of Fe/L). Two-dimensional electrophoresis coupled with matrix-assisted laser desorption/ionization-tandem time-of-flight (MALDI-TOF/TOF) high-resolution tandem mass spectrometry analysis was applied to characterize milk protein composition. Oxidative stability of milk was evaluated by the thiobarbituric acid reactive substances (TBARS) assay for malondialdehyde, and mineral content was measured by inductively coupled plasma mass spectrometry. For milk from both abomasal infusion of ferrous lactate and direct addition of ferrous sulfate, an iron concentration as low as 2mg of Fe/L was able to cause oxidative stress in dairy cattle and infused milk, respectively. Abomasal infusion affected both caseins and whey proteins in the milk, whereas direct addition mainly influenced caseins. Although abomasal iron infusion did not significantly affect oxidation state and mineral balance (except iron), it induced oxidized off-flavor and partial degradation of whey proteins. Direct iron addition to milk led to lipid oxidation during storage at 4°C. Oxidation level was positively associated with the concentration of added iron. Minerals (Mg, P, Na, K, Ca, Zn) in milk were not affected by the added iron in milk. This study indicated that a small amount of iron contamination in bovine drinking water at the farm or incidental iron addition from potable water sources causes oxidation, affects milk protein composition and stability, and affects final milk quality. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Potentiometric Surface of the Magothy Aquifer in Southern Maryland, September 2009

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Staley, Andrew W.

2010-01-01

This report presents a map showing the potentiometric surface of the Magothy aquifer in the Magothy Formation of Late Cretaceous age in Southern Maryland during September 2009. The map is based on water-level measurements in 66 wells. The highest measured water level was 85 feet above sea level near the northern boundary and outcrop area of the aquifer in the north-central part of Anne Arundel County. The potentiometric surface declined towards the south. Local hydraulic gradients were directed toward the center of a cone of depression in the Waldorf area that developed in response to pumping. Measured groundwater levels were as low as 71 feet below sea level in the Waldorf area. The map also shows well yield in gallons per day for 2008 at wells or well fields.

Geometry and Hydraulics of Englacial Conduits, Storglaciaren, Sweden

NASA Astrophysics Data System (ADS)

Fountain, A. G.; Schlichting, R.; Frodin, S.; Jacobel, R. W.

2001-12-01

Englacial conduits are the primary structure responsible for transporting surface water to the base of a glacier, where it supplies the subglacial hydraulic system and, in turn, affects glacier movement. Despite the well-known theoretical descriptions of englacial conduits, little direct evidence exists about their geometry and hydraulics. In July 2001, we initiated a field effort on Storglaciären, Sweden, to intersect englacial conduits by drilling into the glacier using a hot water drill. A companion project (Jacobel et al., this session) attempted to detect the englacial conduits using ground-penetrating radar. In a typical borehole, the water level remained at the surface while drilling through the impermeable ice. Once a connection was made, the water level dropped roughly 10 m and remained low despite continued water pumping. A small video camera was lowered, with attachments, to measure the geometry of the opening, and water flow speed. The water level in the hole provided a piezometric measure of the pressure. We drilled 22 holes at 3 separate locations and 17 (77%) connected englacially, the remaining 5 reached the bed without englacial connection, of which 2 drained at the bed. The geometry of the connections was highly irregular in cross-section with 1-2 cm openings, reminiscent of crevasse-like features rather than circular cross-sections as anticipated from the theoretical literature. Flow behavior was observed by tracking particle motion. The flow was complicated, in part by the inferred tangential intersection between the borehole and structure, and by the observed surging behavior. Flow speeds were low, on the order of 1 cm sec-1. Water level records from 3 different holes over several days exhibited highly correlated variations and large diurnal excursions. In contrast, records from holes drilled to the bed showed little variation. Based on these measurements, our conceptual picture of the englacial system is that of a sluggish flow system composed of many passages with hydraulically inefficient cross-sections. In general, correlation between the radar images and directly measured connections was inconclusive. However, in one case we believe we drilled to a very clear linear subsurface structure imaged by the radar.

Regional-scale impact of storm surges on groundwaters of Texas, Florida and Puerto Rico after 2017 hurricanes Harvey, Irma, Jose, Maria

NASA Astrophysics Data System (ADS)

Sellier, W. H.; Dürr, H. H.

2017-12-01

Hurricanes and related storm surges have devastating effects on near-shore infrastructure and above-ground installations. They also heavily impact groundwater resources, with potentially millions of people dependant on these resources as a freshwater source. Destructions of casings and direct incursions of saline and/or polluted waters have been widely observed. It is uncertain how extensive the effects are on underground water systems, especially in limestone karst areas such as Florida and Puerto Rico. Here, we report regional-scale water level changes in groundwater systems of Texas, Florida and Puerto Rico for the 2017 Hurricanes Harvey, Irma, Jose and Maria. We collected regional scale data from the USGS Waterdata portal. Puerto Rico shows the strongest increase in groundwater levels in wells during Hurricane Maria, with less reaction for the preceding storms Irma and Jose. Increases in water levels range from 0.5 to 11m, with maximum storm surges in Puerto Rico around 3m. These wells are located throughout Puerto Rico, on the coast and inland. In Florida, most wells that show a response during Hurricane Irma are located in the Miami region. Wells located on the west coast show smaller responses with the exception of one well located directly on Hurricane Irma's track. These wells show an increase of 0.2 to 1.7m. In Texas, wells located in proximity to Hurricane Harvey's track show an increase in water level. The effect of groundwater level increases is not limited to the Texas coast, but inland as well. An increase between 0.03 and 2.9m is seen. Storm surges for both Florida and Texas have ranged from 1.8-3.7m maximum. We discuss the findings in the context of local and regional geology and hydrogeology (presence of connected aquifer systems, faulting, presence of carbonate/karst systems etc.).

Concentrations and possible sources of nitrate in water from the Silurian-Devonian aquifer, Cedar Falls, Iowa

USGS Publications Warehouse

Schaap, Bryan D.

1999-01-01

Nitrogen fertilizer sales in Iowa have been higher in recent years than during the mid- 1970’s. This suggests that nitrate concentrations in water from well 9 may persist at present levels or could increase in future years if fertilizer use increases and if higher nitrate concentrations are directly related to higher nitrogen fertilizer use.

Chemical, physical, and radiological quality of selected public water supplies in Florida, November 1977-February 1978

USGS Publications Warehouse

Irwin, G.A.; Hull, Robert W.

1979-01-01

Virtually all treated public water supplies sampled in Florida meet the National Interim Primary and Proposed Secondary Drinking Water Regulations. These findings are based on a water-quality reconnaissance of 129 treated public supplies throughout the State during the period November 1977 through February 1978. While primary drinking water regulation exceedences were infrequent, lead, selenium, and gross alpha radioactivity in a very few water supplies were above established maximum contaminant levels. Additionally, the secondary drinking water regulation parameters--dissolved solids , chloride, sulfate, iron, color, and pH--were occasionally detected in excess of the proposed Federal regulations. The secondary regulations, however, pertain mainly to the aesthetic quality of drinking water and not directly to public health aspects. (Woodard-USGS)

A generalized fuzzy credibility-constrained linear fractional programming approach for optimal irrigation water allocation under uncertainty

NASA Astrophysics Data System (ADS)

Zhang, Chenglong; Guo, Ping

2017-10-01

The vague and fuzzy parametric information is a challenging issue in irrigation water management problems. In response to this problem, a generalized fuzzy credibility-constrained linear fractional programming (GFCCFP) model is developed for optimal irrigation water allocation under uncertainty. The model can be derived from integrating generalized fuzzy credibility-constrained programming (GFCCP) into a linear fractional programming (LFP) optimization framework. Therefore, it can solve ratio optimization problems associated with fuzzy parameters, and examine the variation of results under different credibility levels and weight coefficients of possibility and necessary. It has advantages in: (1) balancing the economic and resources objectives directly; (2) analyzing system efficiency; (3) generating more flexible decision solutions by giving different credibility levels and weight coefficients of possibility and (4) supporting in-depth analysis of the interrelationships among system efficiency, credibility level and weight coefficient. The model is applied to a case study of irrigation water allocation in the middle reaches of Heihe River Basin, northwest China. Therefore, optimal irrigation water allocation solutions from the GFCCFP model can be obtained. Moreover, factorial analysis on the two parameters (i.e. λ and γ) indicates that the weight coefficient is a main factor compared with credibility level for system efficiency. These results can be effective for support reasonable irrigation water resources management and agricultural production.

Quantifying Energy and Water Savings in the U.S. Residential Sector.

PubMed

Chini, Christopher M; Schreiber, Kelsey L; Barker, Zachary A; Stillwell, Ashlynn S

2016-09-06

Stress on water and energy utilities, including natural resource depletion, infrastructure deterioration, and growing populations, threatens the ability to provide reliable and sustainable service. This study presents a demand-side management decision-making tool to evaluate energy and water efficiency opportunities at the residential level, including both direct and indirect consumption. The energy-water nexus accounts for indirect resource consumption, including water-for-energy and energy-for-water. We examine the relationship between water and energy in common household appliances and fixtures, comparing baseline appliances to ENERGY STAR or WaterSense appliances, using a cost abatement analysis for the average U.S. household, yielding a potential annual per household savings of 7600 kWh and 39 600 gallons, with most upgrades having negative abatement cost. We refine the national average cost abatement curves to understand regional relationships, specifically for the urban environments of Los Angeles, Chicago, and New York. Cost abatement curves display per unit cost savings related to overall direct and indirect energy and water efficiency, allowing utilities, policy makers, and homeowners to consider the relationship between energy and water when making decisions. Our research fills an important gap of the energy-water nexus in a residential unit and provides a decision making tool for policy initiatives.

Multiple modes of water quality impairment by fecal contamination in a rapidly developing coastal area: southwest Brunswick County, North Carolina.

PubMed

Cahoon, Lawrence B; Hales, Jason C; Carey, Erin S; Loucaides, Socratis; Rowland, Kevin R; Toothman, Byron R

2016-02-01

Fecal contamination of surface waters is a significant problem, particularly in rapidly developing coastal watersheds. Data from a water quality monitoring program in southwest Brunswick County, North Carolina, gathered in support of a regional wastewater and stormwater management program were used to examine likely modes and sources of fecal contamination. Sampling was conducted at 42 locations at 3-4-week intervals between 1996 and 2003, including streams, ponds, and estuarine waters in a variety of land use settings. Expected fecal sources included human wastewater systems (on-site and central), stormwater runoff, and direct deposition by animals. Fecal coliform levels were positively associated with rainfall measures, but frequent high fecal coliform concentrations at times of no rain indicated other modes of contamination as well. Fecal coliform levels were also positively associated with silicate levels, a groundwater source signal, indicating that flux of fecal-contaminated groundwater was a mode of contamination, potentially elevating FC levels in impacted waters independent of stormwater runoff. Fecal contamination by failing septic or sewer systems at many locations was significant and in addition to effects of stormwater runoff. Rainfall was also linked to fecal contamination by central sewage treatment system failures. These results highlight the importance of considering multiple modes of water pollution and different ways in which human activities cause water quality degradation. Management of water quality in coastal regions must therefore recognize diverse drivers of fecal contamination to surface waters.

Relation of drainage problems to high ground-water levels, Coconut Grove area, Oahu, Hawaii

USGS Publications Warehouse

Swain, L.A.; Huxel, C.J.

1971-01-01

Purpose and Scope In 1969, hydrologic data-collection sites were established in and around the Coconut Grove area for the purpose of measuring directly the relationship between rainfall, runoff, ground-water levels, the level of water in Kawainui Swamp and the canals, and tidal fluctuations. The primary objective was to identify the causes of the occurrence and persistence of flooding and to gain data on which to base recommendations for remedial action. The scope of the study included establishing and operating flow and stage-recording gages on the Swamp, Kawainui Canal, and the inner canal; periodic and repeated measurements of ground-water level in test borings throughout the residential area; collection and analysis of soil and construction borings made for engineering purposes; the assembly and analysis of all available data relating surface and subsurface flow conditions, and the development of conclusions as to the causes and means to alleviate the flooding. This report summarizes the information collected from October 1969 to June 1971, includes analysis of the data, and discusses the probable causes of flooding.

Copper and zinc levels in soil, water, wheat, and hair of inhabitants of three areas of the Orenburg region, Russia.

PubMed

Salnikova, Elena V; Burtseva, Tatiana I; Skalnaya, Margarita G; Skalny, Anatoly V; Tinkov, Alexey A

2018-06-07

The objective of the present study was to assess the level of zinc and copper in soil, water, wheat and hair of inhabitants of the western, central, and eastern areas of the Orenburg region. A total of 525 water, soil, and wheat samples, as well as 420 hair samples were assessed using atomic absorption spectrometry (water, soil, wheat) and inductively-coupled plasma mass spectrometry (hair). The highest levels of Zn and Cu in water (4.9(4.2-5.1) and 1.0(0.9-1.1) mg/l), soil (23.8(20.7-27.0) and 2.6(1.9-3.1) mg/kg), and wheat (24.7(20.5-31.0) and 4.8(4.2-5.5) mg/kg) were observed in the eastern area (p < 0.001). Hair zinc levels in inhabitants of the western (184(165-198) µg/g) and eastern (224(211-253) µg/g) areas of the region exceeded the respective values from the central area by 32% and 61% (p < 0.001). In turn, hair Cu levels in the central (16.4(14.3-17.8) µg/g) and eastern (17.9(16.4-19.0) µg/g) areas exceeded the values from the western area by 10% and 20%, respectively. Correlation analysis demonstrated that hair Zn levels were positively correlated with water and soil content, whereas wheat Zn levels were associated with soil and water content. For copper significant direct correlation was observed only between soil and water Cu content. In multiple regression models, only water zinc level was significantly associated with hair Zn content, although the general model accounted for 55% of variability of hair Zn content. Higher zinc and copper exposure in the eastern area is presumably associated with higher activity of metal-processing industry. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

Descriptions and characterizations of water-level data and groundwater flow for the Brewster Boulevard and Castle Hayne Aquifer Systems and the Tarawa Terrace Aquifer

USGS Publications Warehouse

Faye, Robert E.; Jones, L. Elliott; Suárez-Soto, René J.

2013-01-01

This supplement of Chapter A (Supplement 3) summarizes results of analyses of groundwater-level data and describes corresponding elements of groundwater flow such as vertical hydraulic gradients useful for groundwater-flow model calibration. Field data as well as theoretical concepts indicate that potentiometric surfaces within the study area are shown to resemble to a large degree a subdued replica of surface topography. Consequently, precipitation that infiltrates to the water table flows laterally from highland to lowland areas and eventually discharges to streams such as Northeast and Wallace Creeks and New River. Vertically downward hydraulic gradients occur in highland areas resulting in the transfer of groundwater from shallow relatively unconfined aquifers to underlying confined or semi-confined aquifers. Conversely, in the vicinity of large streams such as Wallace and Frenchs Creeks, diffuse upward leakage occurs from underlying confined or semi-confined aquifers. Point water-level data indicating water-table altitudes, water-table altitudes estimated using a regression equation, and estimates of stream levels determined from a digital elevation model (DEM) and topographic maps were used to estimate a predevelopment water-table surface in the study area. Approximate flow lines along hydraulic gradients are shown on a predevelopment potentiometric surface map and extend from highland areas where potentiometric levels are greatest toward streams such as Wallace Creek and Northeast Creek. The distribution of potentiometric levels and corresponding groundwater-flow directions conform closely to related descriptions of the conceptual model.

Forecasting in an integrated surface water-ground water system: The Big Cypress Basin, South Florida

NASA Astrophysics Data System (ADS)

Butts, M. B.; Feng, K.; Klinting, A.; Stewart, K.; Nath, A.; Manning, P.; Hazlett, T.; Jacobsen, T.

2009-04-01

The South Florida Water Management District (SFWMD) manages and protects the state's water resources on behalf of 7.5 million South Floridians and is the lead agency in restoring America's Everglades - the largest environmental restoration project in US history. Many of the projects to restore and protect the Everglades ecosystem are part of the Comprehensive Everglades Restoration Plan (CERP). The region has a unique hydrological regime, with close connection between surface water and groundwater, and a complex managed drainage network with many structures. Added to the physical complexity are the conflicting needs of the ecosystem for protection and restoration, versus the substantial urban development with the accompanying water supply, water quality and flood control issues. In this paper a novel forecasting and real-time modelling system is presented for the Big Cypress Basin. The Big Cypress Basin includes 272 km of primary canals and 46 water control structures throughout the area that provide limited levels of flood protection, as well as water supply and environmental quality management. This system is linked to the South Florida Water Management District's extensive real-time (SCADA) data monitoring and collection system. Novel aspects of this system include the use of a fully distributed and integrated modeling approach and a new filter-based updating approach for accurately forecasting river levels. Because of the interaction between surface- and groundwater a fully integrated forecast modeling approach is required. Indeed, results for the Tropical Storm Fay in 2008, the groundwater levels show an extremely rapid response to heavy rainfall. Analysis of this storm also shows that updating levels in the river system can have a direct impact on groundwater levels.

Punched belt hole position deviation analysis of float type water level gauge

NASA Astrophysics Data System (ADS)

Mao, Chunlei; Wang, Tao; Fu, Weijie; Li, Lianhui

2018-03-01

The key parts of the float type water level gauge instrument is perforated belt, The size and tolerance requirements of its aperture is: (1) alternation of 100+0.2 and 100-0.2, (2) 200±0.1, (3) 1000±0.15, (4) 10000±0.2. The single hole position: alternation of 100+0.2 and 100-0.2; double: 200±0.1, and ensure the best hole position error avoidance tends to be one-way, that is to say: when the punched belt combined with a water wheel rotating line moving, The hole position error to single direction increase or decrease, caused the water level nail gradually and close to the edge of the hole, and then edge and final punched belt was lifted. This paper uses the laser drilling process of steel strip for data collection and analysis. It is found that this method cannot meet the tolerance requirements and the double stamping processing method with adjustable cylindrical pin is feasible.

Use pattern of pesticides and their predicted mobility into shallow groundwater and surface water bodies of paddy lands in Mahaweli river basin in Sri Lanka.

PubMed

Aravinna, Piyal; Priyantha, Namal; Pitawala, Amarasooriya; Yatigammana, Sudharma K

2017-01-02

Pesticides applied on agricultural lands reach groundwater by leaching, and move to offsite water bodies by direct runoff, erosion and spray drift. Therefore, an assessment of the mobility of pesticides in water resources is important to safeguard such resources. Mobility of pesticides on agricultural lands of Mahaweli river basin in Sri Lanka has not been reported to date. In this context, the mobility potential of 32 pesticides on surface water and groundwater was assessed by widely used pesticide risk indicators, such as Attenuation Factor (AF) index and the Pesticide Impact Rating Index (PIRI) with some modifications. Four surface water bodies having greater than 20% land use of the catchment under agriculture, and shallow groundwater table at 3.0 m depth were selected for the risk assessment. According to AF, carbofuran, quinclorac and thiamethoxam are three most leachable pesticides having AF values 1.44 × 10 -2 , 1.87 × 10 -3 and 5.70 × 10 -4 , respectively. Using PIRI, offsite movement of pesticides by direct runoff was found to be greater than with the erosion of soil particles for the study area. Carbofuran and quinclorac are most mobile pesticides by direct runoff with runoff fractions of 0.01 and 0.08, respectively, at the studied area. Thiamethoxam and novaluron are the most mobile pesticides by erosion with erosion factions of 1.02 × 10 -4 and 1.05 × 10 -4 , respectively. Expected pesticide residue levels in both surface and groundwater were predicted to remain below the USEPA health advisory levels, except for carbofuran, indicating that pesticide pollution is unlikely to exceed the available health guidelines in the Mahaweli river basin in Sri Lanka.

Organochlorine compounds in ice melt water from Italian Alpine rivers.

PubMed

Villa, Sara; Negrelli, Christian; Finizio, Antonio; Flora, Onelio; Vighi, Marco

2006-01-01

Organochlorine chemicals (OCs) (dichlorodiphenyltrichloroethanes, hexachlorocyclohexanes, and hexachlorobenzene) were measured in ice melt water from five glaciers in the Italian Alps. Even though the data collected may not be sufficient for a precise description of persistent organic pollutant release patterns from glacier melting, they have, however, highlighted the potential for surface water contamination. Concentrations were of the same order of magnitude in all glacial streams, indicating comparable contamination levels in different glaciers of the alpine region. OC levels in nonglacial springs sampled in the same areas are usually lower. Even if differences during the melting season (from spring to autumn) have been identified, a regular seasonal pattern in OC concentrations was not observed. Risk for the aquatic environment is excluded through direct water exposure, but it is likely to occur through biomagnification and secondary poisoning exposure.

Experiment T001: Entry communication on the Gemini 3 mission

NASA Technical Reports Server (NTRS)

Schroeder, L. C.; Sims, T. E.; Cuddihy, W. F.

1971-01-01

Water addition to the Gemini 3 exhaust plasma was studied to determine its effectiveness in the establishment of communication links during the entry portion of the flight. Attenuation levels were measured with and without water injection at uhf frequencies of 230.4 and 296.8 megahertz and at the C-band frequency of 5690 megahertz. Ultrahigh frequency signals that had been blacked out were restored to significant levels, during early portions of the water-injection sequence, by the high flow rate injection. The C-band signal was enhanced by medium and high flow rate injections during the latter portion of the injection period. The uhf signal recovered during water injection resulted in an antenna pattern that was beamed in the radial direction of injection from the spacecraft. Postflight analysis showed that the uhf recovery data were consistent with injection-penetration theory.

Use of borehole and surface geophysics to investigate ground-water quality near a road-deicing salt-storage facility, Valparaiso, Indiana

USGS Publications Warehouse

Risch, M.R.; Robinson, B.A.

2001-01-01

Two surface surveys of terrain electromagnetic conductivity were used to map the horizontal extent of the saltwater plume in areas without monitoring wells. Background values of terrain conductivity were measured in an area where water-quality and borehole geophysical data did not indicate saline or brackish water. Based on a guideline from previous case studies, the boundaries of the saltwater plume were mapped where terrain conductivity was 1.5 times background. The extent of the saltwater plume, based on terrain conductivity, generally was consistent with the available water-quality and borehole electromagnetic-conductivity data and with directions of ground-water flow determined from water-level altitudes.

Carbonate dissolution in mixed waters due to ocean acidification

NASA Astrophysics Data System (ADS)

Koski, K.; Wilson, J. L.

2009-12-01

Much of the anthropogenically released carbon dioxide has been stored as a dissolved gas in the ocean, causing a 0.1 decrease in ocean surface pH, with models predicting that by 2100 the surface ocean pH will be 0.5 below pre-industrial levels. In mixed ocean water - fresh water environments (e.g. estuaries, coastal aquifers, and edges of ice sheets), the decreased ocean pH couples with the mixed water geochemistry to make water more undersaturated with respect to calcium carbonate than ocean acidification alone. Mixed-water calcite dissolution may be one of the first directly observable effects of ocean acidification, as the ocean water and the fresh water can both be saturated with respect to calcium carbonate while their mixture will be undersaturated. We present a basic quantitative model describing mixed water dissolution in coastal or island freshwater aquifers, using temporally changing ocean pH, sea level, precipitation, and groundwater pumping. The model describes the potential for an increased rate of speleogenesis and porosity/permeability development along the lower edge of a fresh water lens aquifer. The model accounts the indirect effects of rising sea level and a growing coastal population on these processes. Applications are to freshwater carbonate aquifers on islands (e.g. the Bahamas) and in coastal areas (e.g. the unconfined Floridan aquifer of the United States, the Yucatan Peninsula of Mexico).

Incidence of heavy metal contamination in water supplies in northern Mexico.

PubMed

Wyatt, C J; Fimbres, C; Romo, L; Méndez, R O; Grijalva, M

1998-02-01

Contaminants in drinking water present public health risks. The objective of this study was to analyze water samples taken from wells or storage tanks, direct sources for domestic water in Northern Mexico, for the presence of lead (Pb), copper (Cu), cadmium (Cd), arsenic (As), and mercury (Hg). The samples were analyzed by atomic absorption coupled with a hydride generator or a graphite furnace. High levels of Pb (0.05-0.12 ppm) were found in Hermosillo, Guaymas, and Nacozari. Forty-three percent of the samples in Sonora exceeded the action level (0.015 ppm) established by the EPA for Pb. For As, 8.92% exceeded the limit with a range of 0.002-0.305 ppm. Several studies have indicated a possible link between As and fluoride (F) in drinking water. This study showed a positive correlation between F and As (r = 0.53, P = 0.01, and n = 116). One location in Hermosillo had 7.36 ppm of F and 0.117 ppm of As, 3.5 times the recommended F levels in drinking water and 2 times higher than the level permitted for As. Hg contamination was found in 42% of the samples. Based on the results of this study, it appears that As, Hg, and Pb contamination in the drinking water for some areas of the state of Sonora is a major concern.

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.

Direct evidence of warm water access to the Totten Glacier sub-ice shelf cavity

NASA Astrophysics Data System (ADS)

Orsi, A. H.; Rintoul, S. R.; Silvano, A.; van Wijk, E.; Pena-Molino, B.; Rosenberg, M. A.

2015-12-01

The Totten Glacier holds enough ice to raise global sea level by 3.5 m, is thinning according to (some) satellite data, and is grounded well below sea level on a retrograde bed and hence is potentially unstable. Basal melt driven by ocean heat flux has been linked to ice shelf thinning elsewhere in Antarctica, but no oceanographic measurements had been made near the Totten. In January 2015 the RSV Aurora Australis was the first ship to reach the Totten calving front. Observations from ship-board CTD, moorings and profiling floats provide direct confirmation that warm water reaches the ice shelf cavity. Warm water is present near the sea floor at every station deeper than 300 m depth, with maximum temperatures at mid-shelf >0.5°C. Mooring data confirm that the warm water is present year-round. A deep (>1100 m) channel at the calving front allows warm water (-0.4°C, >2°C above the local freezing point) to access the ice shelf cavity. The contrast between the oceanographic conditions near the Totten and near the Mertz Glacier is stark, although they are separated by only 30 degrees of longitude. East Antarctic ice shelves have often been assumed to behave in a similar manner and to be invulnerable to ocean change; these measurements suggest these assumptions need to be reconsidered.

Sediment properties and water movement through shallow unsaturated alluvium at an arid site for disposal of low-level radioactive waste near Beatty, Nye County, Nevada

USGS Publications Warehouse

Fischer, Jeffrey M.

1992-01-01

A commercial disposal facility for low-level radioactive waste has been in operation near Beatty, Nevada, since 1962. The facility is in the arid Amargosa Desert where wastes are buried in trenches excavated into unsaturated alluvial sediments. Thick unsaturated zones in arid environments offer many potential advantages for disposal of radioactive wastes, but little is known about the natural movement of water near such facilities. Thus, a study was begun in 1982 to better define the direction and rates of water movement through the unsaturated zone in undisturbed sediments near the disposal facility. This report discusses the analyses of data collected between 1983 and 1988.

Louisiana ground-water map no. 1: potentiometric surface, 1985, and water-level changes, 1983-85, of the Chicot aquifer in southwestern Louisiana

USGS Publications Warehouse

Fendick, Robert B.; Nyman, Dale J.

1987-01-01

The Chicot aquifer is the principle source of groundwater in southwestern Louisiana and is the most extensively pumped (nearly 1 billion gallons per day) aquifer in the State. Withdrawals from the Chicot aquifer are used primarily for irrigation. Two maps show the generalized potentiometric surfaces of the upper sand unit ('200-ft ' sand in the Lake Charles area) and the ' 500-ft ' sand of the Chicot aquifer. General water level altitudes and flow directions may be inferred from these maps which were prepared in cooperation with the Louisiana Department of Transportation and Development, Office of Public Works. Previous studies of groundwater hydrology in southwestern Louisiana are included in selected references. (Lantz-PTT)

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.

Evaluating trihalomethane content in drinking water on the basis of common monitoring parameters: regression models.

PubMed

Espigares, Miguel; Lardelli, Pablo; Ortega, Pedro

2003-10-01

The presence of trihalomethanes (THMs) in potable-water sources is an issue of great interest because of the negative impact THMs have on human health. The objective of this study was to correlate the presence of trihalomethanes with more routinely monitored parameters of water quality, in order to facilitate THM control. Water samples taken at various stages of treatment from a water treatment plant were analyzed for the presence of trihalomethanes with the Fujiwara method. The data collected from these determinations were compared with the values obtained for free-residual-chlorine and combined-residual-chlorine levels as well as standard physico-chemical and microbiological indicators such as chemical oxygen demand (by the KMnO4 method), total chlorophyll, conductivity, pH, alkalinity, turbidity, chlorides, sulfates, nitrates, nitrites, phosphates, ammonia, calcium, magnesium, heterotrophic bacteria count, Pseudomonas spp., total and fecal coliforms, and fecal streptococci. The data from these determinations were compiled, and statistical analysis was performed to determine which variables correlate best with the presence and quantity of trihalomethanes in the samples. Levels of THMs in water seem to correlate directly with levels of combined residual chlorine and nitrates, and inversely with the level of free residual chlorine. Statistical analysis with multiple linear regression was conducted to determine the best-fitting models. The models chosen incorporate between two and four independent variables and include chemical oxygen demand, nitrites, and ammonia. These indicators, which are commonly determined during the water treatment process, demonstrate the strongest correlation with the levels of trihalomethanes in water and offer great utility as an accessible method for THM detection and control.

Assessment of complex water pollution with heavy metals and Pyrethroid pesticides on transcript levels of metallothionein and immune related genes.

PubMed

Ghazy, Haneen A; Abdel-Razek, Mohamed A S; El Nahas, Abeer F; Mahmoud, Shawky

2017-09-01

Alteration of immunological function of an aquatic organism can be used as an indicator for evaluating the direct effect of exposure to pollutants. The aim of this work is to assess the impact of complex water pollution with special reference to Pyrethroid pesticides and heavy metals on mRNA transcript levels of Metallothionine and some immune related genes of Nile tilapia (Oreochromas Niloticus). Residues of six heavy metals and six Pyrethroid were assessed in water as well as fish tissues at three different sites of Lake Burullus, located at Northern Egypt. Variations of water physicochemical properties associated with different levels of heavy metals at the three different sections were recorded. Tissue residues of Fe, Mn and Zn, Cu, Ni exceed water levels in contrast to elevated water level of Pb. All assessed Pyrethroids are detected in fish tissue samples with higher concentration (3-42 folds) than that found in water samples especially Cypermethrin. Significant down-regulation of expression levels of metallothionein (MT) at the three sections of the lake was observed. The expression of immune related genes (IgM) and inflammatory cytokines (TNF, IL.8 and IL.1) were affected. IgM and TNF were significantly down-regulated at eastern and western section of the lake; meanwhile the expression of IL8 is down regulated at the three sections of the lack. IL1 was significantly up-regulated at eastern and middle sections. We conclude that, variable gene expression of MT and immune-related genes at the three sections of the lack impose different response to complex water pollution in relation to variable aquatic environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integrating long-term water and sediment pollution data, in assessing chemical status within the European Water Framework Directive.

PubMed

Tueros, Itziar; Borja, Angel; Larreta, Joana; Rodríguez, J Germán; Valencia, Victoriano; Millán, Esmeralda

2009-09-01

The European Water Framework Directive (WFD) establishes a framework for the protection and improvement of estuarine (transitional) and coastal waters, attempting to achieve good water status by 2015; this includes, within the assessment, biological and chemical elements. The European Commission has proposed a list of priority dangerous substances (including metals such as Cd, Hg, Ni and Pb), with the corresponding list of environmental quality standards (EQS), to assess chemical status, but only for waters. In this contribution, a long-term (1995-2007) dataset of transitional and coastal water and sediment trace elements concentrations, from the Basque Country (northern Spain), has been used to investigate the response of these systems to water treatment programmes. Moreover, the approach proposed in the WFD, for assessing water chemical status (the 'one out, all out' approach), is compared with the integration of water and sediment data, into a unique assessment. For this exercise, background levels are used as reference conditions, identifying the boundary between high and good chemical status. EQS are used as the boundary between good and moderate chemical status. This contribution reveals that the first approach can lead to misclassification, with the second approach representing the pattern shown by the long-term data trends. Finally, the management implications, using each approach are discussed.

Water use implications of biofuel scenarios

NASA Astrophysics Data System (ADS)

Teter, J.; Mishra, G. S.; Yeh, S.

2012-12-01

Existing studies rely upon attributional lifecycle analysis (LCA) approaches to estimate water intensity of biofuels in liters of irrigated/evapotranspiration water consumed for biofuel production. Such approaches can be misleading. From a policy perspective, a better approach is to compare differential water impacts among scenarios on a landscape scale. We address the shortcomings of existing studies by using consequential LCA, and incorporate direct and indirect land use (changes) of biofuel scenarios, marginal vs. average biofuel water use estimates, future climate, and geographic heterogeneity. We use the outputs of a partial equilibrium economic model, climate and soil data, and a process-based crop-soil-climate-water model to estimate differences in green water (GW - directly from precipitation to soil) and blue water (BW - supplied by irrigation) use among three scenarios: (1) business-as-usual (BAU), (2) Renewable Fuels Standard (RFS) mandates, and (3) a national Low Carbon Fuel Standard (LCFS) plus the RFS scenario. We use spatial statistical methods to interpolate key climatic variables using daily climate observations for the contiguous USA. Finally, we use FAO's crop model AquaCrop to estimate the domestic GW and BW impacts of biofuel policies from 2007-2035. We assess the differences among scenarios along the following metrics: (1) crop area expansion at the county level, including prime and marginal lands, (2) crop-specific and overall annual/seasonal water balances including (a) water inflows (irrigation & precipitation), (b) crop-atmosphere interactions: (evaporation & transpiration) and (d) soil-water flows (runoff & soil infiltration), in mm 3 /acre over the relevant time period. The functional unit of analysis is the BW and GW requirements of biofuels (mm3 per Btu biofuel) at the county level. Differential water use impacts among scenarios are a primarily a function of (1) land use conversion, in particular that of formerly uncropped land classes (2) irrigation practices, (3) feedstock water use efficiency, and (4) the longer growing season and a predominance of rainfed cultivation of dedicated biofuel feedstocks. National-level total water use is lowest in the BAU scenario and highest in the RFS2 + LCFS scenario. Figure: Million acres converted to growing miscanthus (top) & switchgrass (bottom) under the RFS + LCFS scenario in 2035. Land use classes are crop pasture (blue), idle cropland (red-purple) & prime cropland (brown).

Exploring the capacity of radar remote sensing to estimate wetland marshes water storage.

PubMed

Grings, F; Salvia, M; Karszenbaum, H; Ferrazzoli, P; Kandus, P; Perna, P

2009-05-01

This paper focuses on the use of radar remote sensing for water storage estimation in wetland marshes of the Paraná River Delta in Argentina. The approach followed is based on the analysis of a temporal set of ENVISAT ASAR data which includes images acquired under different polarizations and incidence angles as well as different environmental conditions (water level, precipitation, and vegetation condition). Two marsh species, named junco and cortadera, were monitored. This overall data set gave us the possibility of studying and understanding the basic interactions between the radar, the soil under different flood conditions, and the vegetation structure. The comprehension of the observed features was addressed through electromagnetic models developed for these ecosystems. The procedure used in this work to estimate water level within marshes combines a direct electromagnetic model, field work data specifically obtained to feed the model, the actual ASAR measurements and a well known retrieval scheme based on a cost function. Results are validated with water level evaluations at specific points. A map showing an estimation of the water storage capacity and its error in junco and cortadera areas for the date where the investigation was done is also presented.

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;

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

LaFreniere, L. M.

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at Barnes, Kansas, in 1949-1974. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to characterize this contamination. Those results were reported previously (Argonne 2008a). The results of that investigation indicated that carbon tetrachloride contamination is present in groundwater at low to moderate levels in the vicinity of the former CCC/USDA grain storage facility. Information obtained during the 2006-2007 investigation alsomore » indicated that at least one other potential source might have contributed to the groundwater contaminant plume (Argonne 2008a). The former agriculture building owned by the local school district, located immediately east of well PWS3, is also a potential source of the contamination. In November 2007, the CCC/USDA began periodic groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, under the direction of the Kansas Department of Health and Environment (KDHE). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. Through 2010, sampling was conducted in a network of 28 individual monitoring wells (at 19 distinct locations), 2 public water supply wells, and 1 private well (Figure 1.1). The results of the 2006-2007 targeted investigation and the subsequent monitoring events (Argonne 2008a-d, 2009a,b, 2010) demonstrated the presence of carbon tetrachloride contamination in groundwater at levels exceeding the KDHE Tier 2 risk-based screening level (RBSL) of 5.0 {micro}g/L for this compound. The contaminant plume appears to extend from the former CCC/USDA property northwestward, toward the Barnes public water supply wells. Long-term monitoring of the groundwater levels and the contaminant distribution has confirmed that pumping of the public water supply wells affects the direction of groundwater flow. When these wells are not pumping, the direction of groundwater flow is to the northeast. However, when they are pumping, groundwater flow is directed to the northwest, toward the public wells. A contingency interim measure (Argonne 2009c) has been approved by the KDHE (2009) and will be implemented if the two operating public water supply wells become contaminated at levels above the RBSL of 5.0 {micro}g/L for carbon tetrachloride. This current report presents the results of monitoring conducted in 2010. Sampling of the monitoring well network was conducted in March-April 2010 and September 2010. In addition, the two operating public water supply wells were sampled in June 2010 and December 2010. On the basis of an evaluation of the data collected in 2006-2009 (Argonne 2010), including a trend analysis of the site contamination and its migration, the KDHE (2010) concurred that future monitoring will occur on an annual basis, with twice-yearly sampling of the two public water supply wells in service (conducted in cooperation with the city). The KDHE (2010) also agreed to decrease the number wells to be sampled in the future, as discussed in Section 5.« less

Excel Spreadsheet Tools for Analyzing Groundwater Level Records and Displaying Information in ArcMap

USGS Publications Warehouse

Tillman, Fred D.

2009-01-01

When beginning hydrologic investigations, a first action is often to gather existing sources of well information, compile this information into a single dataset, and visualize this information in a geographic information system (GIS) environment. This report presents tools (macros) developed using Visual Basic for Applications (VBA) for Microsoft Excel 2007 to assist in these tasks. One tool combines multiple datasets into a single worksheet and formats the resulting data for use by the other tools. A second tool produces summary information about the dataset, such as a list of unique site identification numbers, the number of water-level observations for each, and a table of the number of sites with a listed number of water-level observations. A third tool creates subsets of the original dataset based on user-specified options and produces a worksheet with water-level information for each well in the subset, including the average and standard deviation of water-level observations and maximum decline and rise in water levels between any two observations, among other information. This water-level information worksheet can be imported directly into ESRI ArcMap as an 'XY Data' file, and each of the fields of summary well information can be used for custom display. A separate set of VBA tools distributed in an additional Excel workbook creates hydrograph charts of each of the wells in the data subset produced by the aforementioned tools and produces portable document format (PDF) versions of the hydrograph charts. These PDF hydrographs can be hyperlinked to well locations in ArcMap or other GIS applications.

Plant Interactions with Changes in Coverage of Biological Soil Crusts and Water Regime in Mu Us Sandland, China

PubMed Central

Gao, Shuqin; Pan, Xu; Cui, Qingguo; Hu, Yukun; Ye, Xuehua; Dong, Ming

2014-01-01

Plant interactions greatly affect plant community structure. Dryland ecosystems are characterized by low amounts of unpredictable precipitation as well as by often having biological soil crusts (BSCs) on the soil surface. In dryland plant communities, plants interact mostly as they compete for water resources, and the direction and intensity of plant interaction varies as a function of the temporal fluctuation in water availability. Since BSCs influence water redistribution to some extent, a greenhouse experiment was conducted to test the hypothesis that the intensity and direction of plant interactions in a dryland plant community can be modified by BSCs. In the experiment, 14 combinations of four plant species (Artemisia ordosica, Artemisia sphaerocephala, Chloris virgata and Setaria viridis) were subjected to three levels of coverage of BSCs and three levels of water supply. The results show that: 1) BSCs affected plant interaction intensity for the four plant species: a 100% coverage of BSCs significantly reduced the intensity of competition between neighboring plants, while it was highest with a 50% coverage of BSCs in combination with the target species of A. sphaerocephala and C. virgata; 2) effects of the coverage of BSCs on plant interactions were modified by water regime when the target species were C. virgata and S. viridis; 3) plant interactions were species-specific. In conclusion, the percent coverage of BSCs affected plant interactions, and the effects were species-specific and could be modified by water regimes. Further studies should focus on effects of the coverage of BSCs on plant-soil hydrological processes. PMID:24498173

Plant interactions with changes in coverage of biological soil crusts and water regime in Mu Us Sandland, China.

PubMed

Gao, Shuqin; Pan, Xu; Cui, Qingguo; Hu, Yukun; Ye, Xuehua; Dong, Ming

2014-01-01

Plant interactions greatly affect plant community structure. Dryland ecosystems are characterized by low amounts of unpredictable precipitation as well as by often having biological soil crusts (BSCs) on the soil surface. In dryland plant communities, plants interact mostly as they compete for water resources, and the direction and intensity of plant interaction varies as a function of the temporal fluctuation in water availability. Since BSCs influence water redistribution to some extent, a greenhouse experiment was conducted to test the hypothesis that the intensity and direction of plant interactions in a dryland plant community can be modified by BSCs. In the experiment, 14 combinations of four plant species (Artemisia ordosica, Artemisia sphaerocephala, Chloris virgata and Setaria viridis) were subjected to three levels of coverage of BSCs and three levels of water supply. The results show that: 1) BSCs affected plant interaction intensity for the four plant species: a 100% coverage of BSCs significantly reduced the intensity of competition between neighboring plants, while it was highest with a 50% coverage of BSCs in combination with the target species of A. sphaerocephala and C. virgata; 2) effects of the coverage of BSCs on plant interactions were modified by water regime when the target species were C. virgata and S. viridis; 3) plant interactions were species-specific. In conclusion, the percent coverage of BSCs affected plant interactions, and the effects were species-specific and could be modified by water regimes. Further studies should focus on effects of the coverage of BSCs on plant-soil hydrological processes.

Hydrologic assessment of a riparian section along Boulder Creek near Boulder, Colorado, September 1989-September 1991

USGS Publications Warehouse

Kimbrough, Robert

1995-01-01

Native woody riparian species, primarily plains cottonwood (Populus fremontii), are regenerating at less than historical rates along Boulder Creek, a regulated stream near Boulder, Colorado. Loss of native riparian habitats might cause a decline in numbers of some native wildlife species. Previous studies have indicated that streamflow regulation can adversely affect native riparian vegetation reproduction. Surface- and ground-water data were collected from September 1989 to September 1991 along a riparian section of Boulder Creek to assist ecologists in assessing woody plant-recruitment characteristics. Annual mean streamflows in Boulder Creek at Cottonwood Grove of 34.5 cubic feet per second for water year 1990 (October 1, 1989- September 30, 1990) and 34.1 cubic feet per second for water year 1991 were 53 percent less than a site on Boulder Creek about 5 miles upstream from the study area. Diversions dating from 1882 caused most of the decrease. The alluvial aquifer in the study area averaged 5 feet in thickness and consisted of gravel- to cobble-size particles derived from crystalline rock of Precambrian age. The direction of ground-water movement was similar to the direction of streamflow. Ground-water movement in the northeastern part of the grove was affected by a pond constructed at a lower elevation than the stream channel. Water levels in the alluvial aquifer adjacent to the stream pre- dominantly were affected by stream stage, whereas farther from the channel, ground-water levels were affected by other processes such as evapotrans- piration, infiltration, and recharge from urban runoff.

Estimating Spring Condensation on the Great Lakes

NASA Astrophysics Data System (ADS)

Meyer, A.; Welp, L.

2017-12-01

The Laurentian Great Lakes region provides opportunities for shipping, recreation, and consumptive water use to a large part of the United States and Canada. Water levels in the lakes fluctuate yearly, but attempts to model the system are inadequate because the water and energy budgets are still not fully understood. For example, water levels in the Great Lakes experienced a 15-year low period ending in 2013, the recovery of which has been attributed partially to decreased evaporation and increased precipitation and runoff. Unlike precipitation, the exchange of water vapor between the lake and the atmosphere through evaporation or condensation is difficult to measure directly. However, estimates have been constructed using off-shore eddy covariance direct measurements of latent heat fluxes, remote sensing observations, and a small network of monitoring buoys. When the lake surface temperature is colder than air temperature as it is in spring, condensation is larger than evaporation. This is a relatively small component of the net annual water budget of the lakes, but the total amount of condensation may be important for seasonal energy fluxes and atmospheric deposition of pollutants and nutrients to the lakes. Seasonal energy fluxes determine, and are influenced by, ice cover, water and air temperatures, and evaporation in the Great Lakes. We aim to quantify the amount of spring condensation on the Great Lakes using the National Center for Atmospheric Prediction North American Regional Reanalysis (NCEP NARR) Data for Winter 2013 to Spring 2017 and compare the condensation values of spring seasons following high volume, high duration and low volume, low duration ice cover.

Direct damage to vegetation caused by acid rain and polluted cloud: definition of critical levels for forest trees.

PubMed

Cape, J N

1993-01-01

The concept of critical levels was developed in order to define short-term and long-term average concentrations of gaseous pollutants above which plants may be damaged. Although the usual way in which pollutants in precipitation (wet deposition) influence vegetation is by affecting soil processes, plant foliage exposed to fog and cloud, which often contain much greater concentrations of pollutant ions than rain, may be damaged directly. The idea of a critical level has been extended to define concentrations of pollutants in wet deposition above which direct damage to plants is likely. Concentrations of acidity and sulphate measured in mountain and coastal cloud are summarised. Vegetation at risk of injury is identified as montane forest growing close to the cloud base, where ion concentrations are highest. The direct effects of acidic precipitation on trees are reviewed, based on experimental exposure of plants to simulated acidic rain, fog or mist. Although most experiments have reported results in terms of pH (H(+) concentration), the accompanying anion is important, with sulphate being more damaging than nitrate. Both conifers and broadleaved tree seedlings showing subtle changes in the structural characteristics of leaf surfaces after exposure to mist or rain at or about pH 3.5, or sulphate concentration of 150 micromol litre(-1). Visible lesions on leaf surfaces occur at around pH 3 (500 micromol litre(-1) sulphate), broadleaved species tending to be more sensitive than conifers. Effects on photosynthesis and water relations, and interactions with other stresses (e.g. frost), have usually been observed only for treatments which have also caused visible injury to the leaf surface. Few experiments on the direct effects of polluted cloud have been conducted under field conditions with mature trees, which unlike seedlings in controlled conditions, may suffer a growth reduction in the absence of visible injury. Although leaching of cations (Ca(2+), Mg(2+), K(+)) is stimulated by acidic precipitation, amounts leached are small compared with root uptake, unless soils have been impoverished. This aspect of the potential effects of acidic precipitation is best considered in terms of the long-term critical-load of pollutants to the soil. Given the practical difficulties in monitoring cloud water composition, a method for defining critical levels is proposed, which uses climatological average data to identify the duration and frequency of hill cloud, and combines this information with measured or modelled concentrations of particulate sulphate in the atmosphere, to derive cloud water concentrations as a function of cloud liquid water content. For forests within 100 m of the cloud base the critical levels of particulate sulphate, corresponding to solution concentrations in the range 150-500 micromol litre(-1), are in the range 1-3.3 microg S m(-3). These concentrations are observed over much of central Europe, suggesting that many montane forests are at risk of direct effects of fossil-fuel-derived pollutants in cloud.

Degradation of nicotine in water solutions using a water falling film DBD plasma reactor: direct and indirect treatment

NASA Astrophysics Data System (ADS)

Krupež, Jelena; Kovačević, Vesna V.; Jović, Milica; Roglić, Goran M.; Natić, Maja M.; Kuraica, Milorad M.; Obradović, Bratislav M.; Dojčinović, Biljana P.

2018-05-01

Nicotine degradation efficiency in water solutions was studied using a water falling film dielectric barrier discharge (DBD) reactor. Two different treatments were applied: direct treatment, the recirculation of the solution through a DBD reactor, and indirect treatment, the bubbling of the gas from the DBD through the porous filter into the solution. In a separate experiment, samples spiked with nicotine in double distilled water (ddH2O) and tap water were studied and compared after both treatments. Furthermore, the effects of the homogeneous catalysts, namely, Fe2+ and H2O2, were tested in the direct treatment. Nicotine degradation efficiency was determined using high-performance liquid chromatography. A degradation efficiency of 90% was achieved after the direct treatment catalyzed with Fe2+. In order to analyze the biodegradability, mineralization level, and toxicity of the obtained solutions, after all degradation procedures the values of the following parameters were determined: total organic carbon, chemical oxygen demand, biochemical oxygen demand, and the Artemia salina toxicity test. The results showed that an increase in biodegradability was obtained, after all treatments. A partial nicotine mineralization was achieved and the mortality of the A. salina organism decreased in the treated samples, all of which indicating the effective removal of nicotine and the creation of less toxic solutions. Nicotine degradation products were identified using ultrahigh-performance liquid chromatography coupled with a linear ion trap Orbitrap hybrid mass spectrometer and a simple mechanism for oxidative degradation of nicotine in non-thermal plasma systems is proposed.

An estimation method of the direct benefit of a waterlogging control project applicable to the changing environment

NASA Astrophysics Data System (ADS)

Zengmei, L.; Guanghua, Q.; Zishen, C.

2015-05-01

The direct benefit of a waterlogging control project is reflected by the reduction or avoidance of waterlogging loss. Before and after the construction of a waterlogging control project, the disaster-inducing environment in the waterlogging-prone zone is generally different. In addition, the category, quantity and spatial distribution of the disaster-bearing bodies are also changed more or less. Therefore, under the changing environment, the direct benefit of a waterlogging control project should be the reduction of waterlogging losses compared to conditions with no control project. Moreover, the waterlogging losses with or without the project should be the mathematical expectations of the waterlogging losses when rainstorms of all frequencies meet various water levels in the drainage-accepting zone. So an estimation model of the direct benefit of waterlogging control is proposed. Firstly, on the basis of a Copula function, the joint distribution of the rainstorms and the water levels are established, so as to obtain their joint probability density function. Secondly, according to the two-dimensional joint probability density distribution, the dimensional domain of integration is determined, which is then divided into small domains so as to calculate the probability for each of the small domains and the difference between the average waterlogging loss with and without a waterlogging control project, called the regional benefit of waterlogging control project, under the condition that rainstorms in the waterlogging-prone zone meet the water level in the drainage-accepting zone. Finally, it calculates the weighted mean of the project benefit of all small domains, with probability as the weight, and gets the benefit of the waterlogging control project. Taking the estimation of benefit of a waterlogging control project in Yangshan County, Guangdong Province, as an example, the paper briefly explains the procedures in waterlogging control project benefit estimation. The results show that the waterlogging control benefit estimation model constructed is applicable to the changing conditions that occur in both the disaster-inducing environment of the waterlogging-prone zone and disaster-bearing bodies, considering all conditions when rainstorms of all frequencies meet different water levels in the drainage-accepting zone. Thus, the estimation method of waterlogging control benefit can reflect the actual situation more objectively, and offer a scientific basis for rational decision-making for waterlogging control projects.

Hydrodynamic modelling of recreational water quality using Escherichia coli as an indicator of microbial contamination

NASA Astrophysics Data System (ADS)

Eregno, Fasil Ejigu; Tryland, Ingun; Tjomsland, Torulv; Kempa, Magdalena; Heistad, Arve

2018-06-01

Microbial contamination of recreational beaches is often at its worst after heavy rainfall events due to storm floods that carry fecal matter and other pollutants from the watershed. Similarly, overflows of untreated sewage from combined sewerage systems may discharge directly into coastal water or via rivers and streams. In order to understand the effect of rainfall events, wind-directions and tides on the recreational water quality, GEMSS, an integrated 3D hydrodynamic model was applied to assess the spreading of Escherichia coli (E. coli) at the Sandvika beaches, located in the Oslo fjord. The model was also used to theoretically investigate the effect of discharges from septic tanks from boats on the water quality at local beaches. The model make use of microbial decay rate as the main input representing the survival of microbial pathogens in the ocean, which vary widely depending on the type of pathogen and environmental stress. The predicted beach water quality was validated against observed data after a heavy rainfall event using Nash-Sutcliffe coefficient (E) and the overall result indicated that the model performed quite well and the simulation was in - good agreement with the observed E. coli concentrations for all beaches. The result of this study indicated that: 1) the bathing water quality was poor according to the EU bathing water directive up to two days after the heavy rainfall event depending on the location of the beach site. 2) The discharge from a boat at 300-meter distance to the beaches slightly increased the E. coli levels at the beaches. 3) The spreading of microbial pathogens from its source to the different beaches depended on the wind speed and the wind direction.

Groundwater modelling as a tool for the European Water Framework Directive (WFD) application: The Llobregat case

NASA Astrophysics Data System (ADS)

Vázquez-Suñé, E.; Abarca, E.; Carrera, J.; Capino, B.; Gámez, D.; Pool, M.; Simó, T.; Batlle, F.; Niñerola, J. M.; Ibáñez, X.

The European Water Framework Directive establishes the basis for Community action in the field of water policy. Water authorities in Catalonia, together with users are designing a management program to improve groundwater status and to assess the impact of infrastructures and city-planning activities on the aquifers and their associated natural systems. The objective is to describe the role of groundwater modelling in addressing the issues raised by the Water Framework Directive, and its application to the Llobregat Delta, Barcelona, Spain. In this case modelling was used to address Water Framework Directive in the following: (1) Characterisation of aquifers and the status of groundwater by integration of existing knowledge and new hydrogeological information. Inverse modelling allowed us to reach an accurate description of the paths and mechanisms for the evolution of seawater intrusion. (2) Quantification of groundwater budget (mass balance). This is especially relevant for those terms that are difficult to asses, such as recharge from river infiltration during floods, which we have found to be very important. (3) Evaluation of groundwater-related environmental needs in aquatic ecosystems. The model allows quantifying groundwater input under natural conditions, which can be used as a reference level for stressed conditions. (4) Evaluation of possible impacts of territory planning (Llobregat river course modification, new railway tunnels, airport and docks enlargement, etc.). (5) Definition of management areas. (6) The assessment of possible future scenarios combined with optimization processes to quantify sustainable pumping rates and design measures to control seawater intrusion. The resulting model has been coupled to a user-friendly interface to allow water managers to design and address corrective measures in an agile and effective way.

Water Underground

NASA Astrophysics Data System (ADS)

de Graaf, I. E. M.

2014-12-01

The world's largest accessible source of freshwater is hidden underground. However it remains difficult to estimate its volume, and we still cannot answer the question; will there be enough for everybody? In many places of the world groundwater abstraction is unsustainable: more water is used than refilled, leading to decreasing river discharges and declining groundwater levels. It is predicted that for many regions in the world unsustainable water use will increase in the coming decades, due to rising human water use under a changing climate. It would not take long before water shortage causes widespread droughts and the first water war begins. Improving our knowledge about our hidden water is the first step to prevent such large water conflicts. The world's largest aquifers are mapped, but these maps do not mention how much water these aquifers contain or how fast water levels decline. If we can add thickness and geohydrological information to these aquifer maps, we can estimate how much water is stored and its flow direction. Also, data on groundwater age and how fast the aquifer is refilled is needed to predict the impact of human water use and climate change on the groundwater resource. Ultimately, if we can provide this knowledge water conflicts will focus more on a fair distribution instead of absolute amounts of water.

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.

Operating manual for the R200 downhole recorder with husky hunter retriever

USGS Publications Warehouse

Johnson, Roy A.; Rorabaugh, James I.

1988-01-01

The R200 Downhole Recorder is a battery-powered device that, when placed in a well casing, monitors water levels for a period of up to 1 year. This instrument measures a 1- to 70-foot range of water levels. These water-level data can be retrieved through use of a commercially available portable microcomputer. The R200 Downhole Recorder was developed at the U.S. Geological Survey 's Hydrologic Instrumentation Facility, Stennis Space Center, Mississippi. This operating manual describes the R200 Downhole Recorder, provides initial set-up instructions, and gives directions for on-site operation. Design specifications and routine maintenance steps are included. The R200 data-retriever program is a user-friendly, menu-driven program. The manual guides the user through the procedures required to perform specific operations. Numerous screens are reproduced in the text with a discussion of user input for desired responses. Help is provided for specific problems. (USGS)

Operating manual for the R200 downhole recorder with Tandy 102 retriever

USGS Publications Warehouse

Johnson, Roy A.; Rorabaugh, James I.

1988-01-01

The R200 Downhole Recorder is a battery-powered device that, when placed in a well casing, monitors water levels for a period of up to 1 year. This instrument measures a 1- to 70-ft range of water levels. These water level data can be retrieved through use of a commercially available portable microcomputer. The R200 Downhole Recorder was developed at the U. S. Geological Survey 's Hydrologic Instrumentation Facility, Stennis Space Center, Mississippi. This operating manual describes the R200 Downhole Recorder, provides initial set-up instructions, and gives directions for on-site operation. Design specifications and routine maintenance steps are included. The R200 data-retriever program is a user-friendly, menu-driven program. The manual guides the user through the procedures required to perform specific operations. Numerous screens are reproduced in the text with a discussion of user input for desired responses. Help is provided for specific problems. (USGS)

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,.

Potentiometric surface of the Magothy Aquifer in southern Maryland, September 1994

USGS Publications Warehouse

Curtin, Stephen E.; Mack, Frederick K.; Andreasen, David C.

1995-01-01

A map showing the potentiometric surface of the Magothy aquifer in the Magothy Formation of Cretaceous age in southern Maryland during September 1994 was prepared from water levels measured in 85 wells. The potentiometric surface was highest near the northwestern boundary and outcrop area of the aquifer in topographically high areas of Anne Arundel and Prince Georges Counties. Regionally, the potentiometric surface sloped gently downward toward the southeast, and the local gradients were directed toward the centers of three cones of depression that have developed in response to pumping. These cones were centered around well fields in the Annapolis, Waldorf, and Chalk Point areas. Ground-water levels were as low as 60 feet below sea level in the Waldorf area, more than 45 feet below sea level at Chalk Point, and almost 15 feet below sea level near Annapolis.

Potentiometric Surface of the Magothy Aquifer in Southern Maryland, September 1995

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Mack, Frederick K.

1996-01-01

A map showing the potentiometric surface of the Magothy aquifer in the Magothy Formation of Cretaceous age in southern Maryland during September 1995 was prepared from water-level measurements in 92 wells. The potentiometric surface was highest near the northwestern boundaryand outcrop area of the aquifer in topographically high areas of Anne Arundel and Prince Georges Counties. Regionally, the potentiometric surface sloped gently downward towards the southeast and the local gradients were directed toward the centers of three cones of depression that have developed in response to pumping. These cones were centeredaround well fields in the Annapolis, Waldorf, and Chalk Point areas. Ground-water levels were as low as 63 feet below sea level in the Waldorf area, more than 50 feet below sea level at Chalk Point, and almost 20 feet below sea level near Annapolis.

The Impact of Water Table Drawdown and Drying on Subterranean Aquatic Fauna in In-Vitro Experiments

PubMed Central

Stumpp, Christine; Hose, Grant C.

2013-01-01

The abstraction of groundwater is a global phenomenon that directly threatens groundwater ecosystems. Despite the global significance of this issue, the impact of groundwater abstraction and the lowering of groundwater tables on biota is poorly known. The aim of this study is to determine the impacts of groundwater drawdown in unconfined aquifers on the distribution of fauna close to the water table, and the tolerance of groundwater fauna to sediment drying once water levels have declined. A series of column experiments were conducted to investigate the depth distribution of different stygofauna (Syncarida and Copepoda) under saturated conditions and after fast and slow water table declines. Further, the survival of stygofauna under conditions of reduced sediment water content was tested. The distribution and response of stygofauna to water drawdown was taxon specific, but with the common response of some fauna being stranded by water level decline. So too, the survival of stygofauna under different levels of sediment saturation was variable. Syncarida were better able to tolerate drying conditions than the Copepoda, but mortality of all groups increased with decreasing sediment water content. The results of this work provide new understanding of the response of fauna to water table drawdown. Such improved understanding is necessary for sustainable use of groundwater, and allows for targeted strategies to better manage groundwater abstraction and maintain groundwater biodiversity. PMID:24278111

On the asymmetric distribution of shear-relative typhoon rainfall

NASA Astrophysics Data System (ADS)

Gao, Si; Zhai, Shunan; Li, Tim; Chen, Zhifan

2018-02-01

The Tropical Rainfall Measuring Mission (TRMM) 3B42 precipitation, the National Centers for Environmental Prediction (NCEP) Final analysis and the Regional Specialized Meteorological Center (RSMC) Tokyo best-track data during 2000-2015 are used to compare spatial rainfall distribution associated with Northwest Pacific tropical cyclones (TCs) with different vertical wind shear directions and investigate possible mechanisms. Results show that the maximum TC rainfall are all located in the downshear left quadrant regardless of shear direction, and TCs with easterly shear have greater magnitudes of rainfall than those with westerly shear, consistent with previous studies. Rainfall amount of a TC is related to its relative position and proximity from the western Pacific subtropical high (WPSH) and the intensity of water vapor transport, and low-level jet is favorable for water vapor transport. The maximum of vertically integrated moisture flux convergence (MFC) are located on the downshear side regardless of shear direction, and the contribution of wind convergence to the total MFC is far larger than that of moisture advection. The cyclonic displacement of the maximum rainfall relative to the maximum MFC is possibly due to advection of hydrometeors by low- and middle-level cyclonic circulation of TCs. The relationship between TC rainfall and the WPSH through water vapor transport and vertical wind shear implies that TC rainfall may be highly predictable given the high predictability of the WPSH.

Potentiometric Surface of the Aquia Aquifer in Southern Maryland, September 2001

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Wheeler, Judith C.

2002-01-01

This report presents a map showing the potentiometric surface of the Aquia aquifer in the Aquia Formation of Paleocene age in Southern Maryland during September 2001. The map is based on water-level measurements in 76 wells. The potentiometric surface was highest at 40 feet above sea level near the northern boundary and outcrop area of the aquifer in the central part of Anne Arundel County, and was below sea level in the remainder of the study area. The hydraulic gradient was directed southeastward toward an extensive cone of depression around well fields at Lexington Park and Solomons Island. A cone of depression formed in northern Calvert County due to pumpage at Chesapeake Beach and North Beach. The water level has declined to 44 feet below sea level in this area. The lowest measurement was 160 feet below sea level at the center of a cone of depression at Lexington Park.

Assessing remotely sensed chlorophyll-a for the implementation of the Water Framework Directive in European perialpine lakes.

PubMed

Bresciani, Mariano; Stroppiana, Daniela; Odermatt, Daniel; Morabito, Giuseppe; Giardino, Claudia

2011-08-01

The lakes of the European perialpine region constitute a large water reservoir, which is threatened by the anthropogenic pressure altering water quality. The Water Framework Directive of the European Commission aims to protect water resources and monitoring is seen as an essential step for achieving this goal. Remote sensing can provide frequent data for large scale studies of water quality parameters such as chlorophyll-a (chl-a). In this work we use a dataset of maps of chl-a derived from over 200 MERIS (MEdium Resolution Imaging Spectrometer) satellite images for comparing water quality of 12 perialpine lakes in the period 2003-2009. Besides the different trophic levels of the lakes, results confirm that the seasonal variability of chl-a concentration is particularly pronounced during spring and autumn especially for the more eutrophic lakes. We show that relying on only one sample for the assessment of lake water quality during the season might lead to misleading results and erroneous assignments to quality classes. Time series MERIS data represents a suitable and cost-effective technology to fill this gap, depicting the dynamics of the surface waters of lakes in agreement with the evolution of natural phenomena. Copyright © 2011 Elsevier B.V. All rights reserved.

Operation REDWING Commander Task Group 7.3, Operation Plan Number 1-56.

DTIC Science & Technology

1956-01-24

lagoon water samples, when and as directed." "(32) Provide water spray equipment aboard all ships likely to be in the fallout area." 2 I 7 I FF3/7.3/30... coconuts , other fruits, etc.) may contain radiation materials in amounts which could be harmful for human consumption, the eating of any native food...1-8 17... 1 Delete entire paragraph and sutstitute the following: "e. In potable water , a continuous level of 5 x lO-3uc/cc (calculated to H plus

Analytical results from ground-water sampling using a direct-push technique at the Dover National Test Site, Dover Air Force Base, Delaware, June-July 2001

USGS Publications Warehouse

Guertal, William R.; Stewart, Marie; Barbaro, Jeffrey R.; McHale, Timthoy J.

2004-01-01

A joint study by the Dover National Test Site and the U.S. Geological Survey was conducted from June 27 through July 18, 2001 to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site at Dover Air Force Base, Delaware. The study was conducted to support a planned enhanced bio-remediation demonstration and to assist the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. This report presents the analytical results from ground-water samples collected during the direct-push ground-water sampling study. A direct-push drill rig was used to quickly collect 115 ground-water samples over a large area at varying depths. The ground-water samples and associated quality-control samples were analyzed for volatile organic compounds and methyl tert-butyl ether by the Dover National Test Site analytical laboratory. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloroethene, 1.14 micrograms per liter of trichloroethene, 2.65 micrograms per liter of tetrachloroethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest methyl tert-butyl ether concentrations were found in the surficial aquifer from -4.6 to 6.4 feet mean sea level, however, methyl tert-butyl ether was detected as deep as -9.5 feet mean sea level. Increased methane concentrations and decreased dissolved oxygen concentrations were found in samples that contained methyl tert-butyl ether.

Point of no return: experimental determination of the lethal hydraulic threshold during drought for loblolly pine (Pinus taeda)

NASA Astrophysics Data System (ADS)

Hammond, W.; Yu, K.; Wilson, L. A.; Will, R.; Anderegg, W.; Adams, H. D.

2017-12-01

The strength of the terrestrial carbon sink—dominated by forests—remains one of the greatest uncertainties in climate change modelling. How forests will respond to increased variability in temperature and precipitation is poorly understood, and experimental study to better inform global vegetation models in this area is needed. Necessary for achieving­­­­ this goal is an understanding of how increased temperatures and drought will affect landscape level distributions of plant species. Quantifying physiological thresholds representing a point of no return from drought stress, including thresholds in hydraulic function, is critical to this end. Recent theoretical, observational, and modelling research has converged upon a threshold of 60 percent loss of hydraulic conductivity at mortality (PLClethal). However, direct experimental determination of lethal points in conductivity and cavitation during drought is lacking. We quantified thresholds in hydraulic function in Loblolly pine, Pinus taeda, a commercially important timber species. In a greenhouse experiment, we exposed saplings (n = 96 total) to drought and rewatered treatment groups at variable levels of increasing water stress determined by pre-selected targets in pre-dawn water potential. Treatments also included a watered control with no drought, and drought with no rewatering. We measured physiological responses to water stress, including hydraulic conductivity, native PLC, water potential, foliar color, canopy die-back, and dark-adapted chlorophyll fluorescence. Following the rewatering treatment, we observed saplings for at least two months to determine which survived and which died. Using these data we calculated lethal physiological thresholds in water potential, directly measured PLC, and PLC inferred from water potential using a hydraulic vulnerability curve. We found that PLClethal inferred from water potential agreed with the 60% threshold suggested by previous research. However, directly measured PLC supported a much higher threshold. Beyond PLClethal, some trees survived by basal and epicormic re-sprouting, despite complete top-kill of existing foliage. Additional empirical study of multiple species to represent functional groups is needed to provide lethal thresholds for models presently in development.

Direct and indirect effects of the fungicide Carbendazim in tropical freshwater microcosms.

PubMed

Daam, Michiel A; Satapornvanit, Kriengkrai; Van den Brink, Paul J; Nogueira, António J A

2010-02-01

Direct and indirect effects of the fungicide carbendazim on ecosystem structure and functioning were studied < or =8 weeks after application (nominal concentrations: 0, 3.3, 33, 100, and 1000 microg/L) to outdoor microcosms in Thailand. Direct effects on macroinvertebrates are discussed in detail in a separate article. The present article presents the effects on other end points and discusses the hypothesized ecologic effect chain. Negative treatment effects on the zooplankton community were only recorded for the highest carbendazim treatment (NOEC(community) = 100 microg/L). The rotifer Keratella tropica, cladocerans (Moina micrura, Ceriodaphnia cornuta, and Diaphanosoma sp.), and cyclopoid copepods were decreased or even eliminated at this treatment level. The decrease in zooplankton and macroinvertebrate abundances was accompanied by an increase in numbers of several tolerant invertebrates, presumably caused by a release from competition and predation. The death of sensitive invertebrates probably also led to an overall decreased grazing pressure because increased levels of chlorophyll-a and bloom of the floating macrophyte Wolffia sp. were noted. The increase in primary producers is discussed to be the probable cause of changes in physicochemical water conditions, eventually resulting in an anoxic water layer during the last 3 weeks of the experiment. This is likely to have resulted in decreased invertebrate abundances noted in that period. Furthermore, the decreased decomposition of Musa (banana) leaves observed 8 weeks after application is considered to be the indirect effect of a decreased microbial activity resulting from these anoxic water conditions, rather than a direct toxic effect of carbendazim.

Influence of the Institutional Structure of Surface Water Rights on Agricultural Production in the Central Valley

NASA Astrophysics Data System (ADS)

Nelson, K.; Burchfield, E. K.

2017-12-01

California's Central Valley region is one of the most productive agricultural systems on the planet. The high levels of agricultural production in this region require large amounts of fresh water for irrigation. However, the long-term availability of water required to sustain such levels of agricultural production has been questioned following the latest drought in California. In this study, we use Bayesian multilevel spatiotemporal modeling techniques to examine the influence of the institutional structure of surface water rights in the Central Valley on agricultural production during the recent drought. The R-INLA package is employed to account for spatial processes that have the potential to influence the effects of water right structures on crop productivity as well as on extent of cultivation. Model results suggest that seniority in surface water access significantly improves crop productivity on cultivated lands, but does not directly affect the ability to maintain cultivated extent. In addition, results suggest that areas with more junior surface water rights tend to reduce extent of cultivation, but maintain crop productivity, as cumulative drought stress increases.

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.

Using multi-source satellite data for lake level modelling in ungauged basins: A case study for Lake Turkana, East Africa

USGS Publications Warehouse

Velpuri, N.M.; Senay, G.B.; Asante, K.O.

2011-01-01

Managing limited surface water resources is a great challenge in areas where ground-based data are either limited or unavailable. Direct or indirect measurements of surface water resources through remote sensing offer several advantages of monitoring in ungauged basins. A physical based hydrologic technique to monitor lake water levels in ungauged basins using multi-source satellite data such as satellite-based rainfall estimates, modelled runoff, evapotranspiration, a digital elevation model, and other data is presented. This approach is applied to model Lake Turkana water levels from 1998 to 2009. Modelling results showed that the model can reasonably capture all the patterns and seasonal variations of the lake water level fluctuations. A composite lake level product of TOPEX/Poseidon, Jason-1, and ENVISAT satellite altimetry data is used for model calibration (1998-2000) and model validation (2001-2009). Validation results showed that model-based lake levels are in good agreement with observed satellite altimetry data. Compared to satellite altimetry data, the Pearson's correlation coefficient was found to be 0.81 during the validation period. The model efficiency estimated using NSCE is found to be 0.93, 0.55 and 0.66 for calibration, validation and combined periods, respectively. Further, the model-based estimates showed a root mean square error of 0.62 m and mean absolute error of 0.46 m with a positive mean bias error of 0.36 m for the validation period (2001-2009). These error estimates were found to be less than 15 % of the natural variability of the lake, thus giving high confidence on the modelled lake level estimates. The approach presented in this paper can be used to (a) simulate patterns of lake water level variations in data scarce regions, (b) operationally monitor lake water levels in ungauged basins, (c) derive historical lake level information using satellite rainfall and evapotranspiration data, and (d) augment the information provided by the satellite altimetry systems on changes in lake water levels. ?? Author(s) 2011.

Scaling up food production in the Upper Mississippi river basin: modeling impacts on water quality and nutrient cycling

NASA Astrophysics Data System (ADS)

Bowen, E. E.; Martin, P. A.; Schuble, T. J.; Yan, E.; Demissie, Y.

2010-12-01

Agricultural production imposes significant environmental stress on the landscape, both in the intensity and extent of agricultural activities. Among the most significant impacts, agriculture dominates the natural reactive nitrogen cycle, with excess reactive nitrogen leading to the degraded quality of inland and coastal waters. In the U.S., policymakers and stakeholders nationwide continue to debate strategies for decreasing environmental degradation from agricultural lands. Such strategies aim to optimize the balance among competing demands for food, fuel and ecosystem services. One such strategy increasingly discussed in the national debate is that of localizing food production around urban areas, developing what some have recently called “foodsheds”. However, the environmental impacts of localizing food production around population centers are not well-understood given the hard-to-generalize variety seen in management practices currently employed among local farms marketing food crops directly to consumers. As a first, landscape level study of potential impacts from scaling up this type of agriculture, we use the USDA Soil and Water Assessment Tool (SWAT) model to quantify environmental impacts from developing foodsheds for all population centers in the Upper Mississippi river basin. Specifically, we focus on nutrient cycling and water quality impacts determining direct greenhouse gas emissions and changes to nutrient runoff from increased food production in this watershed. We investigate a variety of scenarios in which food production is scaled up to the regional level using different types of farm management practices, ranging from conventional production of fruits and vegetables, to production of these products from small-scale, diversified systems integrating conservation easements. In addition to impacts on nutrient cycling and water quality, we also characterize relative levels of productivity in conjunction with overall demand for food associated with population centers to address one aspect of socio-economic concern.

Preliminary groundwater flow model of the basin-fill aquifers in Detrital, Hualapai, and Sacramento Valleys, Mohave County, northwestern Arizona

USGS Publications Warehouse

Tillman, Fred D.; Garner, Bradley D.; Truini, Margot

2013-01-01

Preliminary numerical models were developed to simulate groundwater flow in the basin-fill alluvium in Detrital, Hualapai, and Sacramento Valleys in northwestern Arizona. The purpose of this exercise was to gather and evaluate available information and data, to test natural‑recharge concepts, and to indicate directions for improving future regional groundwater models of the study area. Both steady-state and transient models were developed with a single layer incorporating vertically averaged hydraulic properties over the model layer. Boundary conditions for the models were constant-head cells along the northern and western edges of the study area, corresponding to the location of the Colorado River, and no-flow boundaries along the bedrock ridges that bound the rest of the study area, except for specified flow where Truxton Wash enters the southern end of Hualapai Valley. Steady-state conditions were simulated for the pre-1935 period, before the construction of Hoover Dam in the northwestern part of the model area. Two recharge scenarios were investigated using the steady-state model—one in which natural aquifer recharge occurs directly in places where water is available from precipitation, and another in which natural aquifer recharge from precipitation occurs in the basin-fill alluvium that drains areas of available water. A transient model with 31 stress periods was constructed to simulate groundwater flow for the period 1935–2010. The transient model incorporates changing Colorado River, Lake Mead, and Lake Mohave water levels and includes time-varying groundwater withdrawals and aquifer recharge. Both the steady-state and transient models were calibrated to available water-level observations in basin-fill alluvium, and simulations approximate observed water-level trends throughout most of the study area.

Ground-water levels in intermontane basins of the northern Rocky Mountains, Montana and Idaho

USGS Publications Warehouse

Briar, David W.; Lawlor, S.M.; Stone, M.A.; Parliman, D.J.; Schaefer, J.L.; Kendy, Eloise

1996-01-01

The Regional Aquifer-System Analysis (RASA) program is a series of studies by the U.S. Geological Survey (USGS) to analyze regional ground-water systems that compose a major portion of the Nation's water supply (Sun, 1986). The Northern Rocky Mountains Intermontane Basins is one of the study regions in this national program. The main objectives of the RASA studies are to (1) describe the groundwater systems as they exist today, (2) analyze the known changes that have led to the systems present condition, (3) combine results of previous studies in a regional analysis, where possible, and (4) provide means by which effects of future ground-water development can be estimated.The purpose of this study, which began in 1990, was to increase understanding of the hydrogeology of the intermontane basins of the Northern Rocky Mountains area. This report is Chapter B of a three-part series and shows the general distribution of ground-water levels in basin-fill deposits in the study area. Chapter A (Tuck and others, 1996) describes the geologic history and generalized hydrogeologic units. Chapter C (Clark and Dutton, 1996) describes the quality of ground and surface waters in the study area.Ground-water levels shown in this report were measured primarily during summer 1991 and summer 1992; however, historical water levels were used for areas where more recent data could not be obtained. The information provided allows for the evaluation of general directions of ground-water flow, identification of recharge and discharge areas, and determination of hydraulic gradients within basin-fill deposits.

Skill assessment of a real-time forecast system utilizing a coupled hydrologic and coastal hydrodynamic model during Hurricane Irene (2011)

NASA Astrophysics Data System (ADS)

Dresback, Kendra M.; Fleming, Jason G.; Blanton, Brian O.; Kaiser, Carola; Gourley, Jonathan J.; Tromble, Evan M.; Luettich, Richard A.; Kolar, Randall L.; Hong, Yang; Van Cooten, Suzanne; Vergara, Humberto J.; Flamig, Zac L.; Lander, Howard M.; Kelleher, Kevin E.; Nemunaitis-Monroe, Kodi L.

2013-12-01

Due to the devastating effects of recent hurricanes in the Gulf of Mexico (e.g., Katrina, Rita, Ike and Gustav), the development of a high-resolution, real-time, total water level prototype system has been accelerated. The fully coupled model system that includes hydrology is an extension of the ADCIRC Surge Guidance System (ASGS), and will henceforth be referred to as ASGS-STORM (Scalable, Terrestrial, Ocean, River, Meteorological) to emphasize the major processes that are represented by the system.The ASGS-STORM system incorporates tides, waves, winds, rivers and surge to produce a total water level, which provides a holistic representation of coastal flooding. ASGS-STORM was rigorously tested during Hurricane Irene, which made landfall in late August 2011 in North Carolina. All results from ASGS-STORM for the advisories were produced in real-time, forced by forecast wind and pressure fields computed using a parametric tropical cyclone model, and made available via the web. Herein, a skill assessment, analyzing wind speed and direction, significant wave heights, and total water levels, is used to evaluate ASGS-STORM's performance during Irene for three advisories and the best track from the National Hurricane Center (NHC). ASGS-STORM showed slight over-prediction for two advisories (Advisory 23 and 25) due to the over-estimation of the storm intensity. However, ASGS-STORM shows notable skill in capturing total water levels, wind speed and direction, and significant wave heights in North Carolina when utilizing Advisory 28, which had a slight shift in the track but provided a more accurate estimation of the storm intensity, along with the best track from the NHC. Results from ASGS-STORM have shown that as the forecast of the advisories improves, so does the accuracy of the models used in the study; therefore, accurate input from the weather forecast is a necessary, but not sufficient, condition to ensure the accuracy of the guidance provided by the system. While Irene provided a real-time test of the viability of a total water level system, the relatively insignificant freshwater discharges precludes definitive conclusions about the role of freshwater discharges on total water levels in estuarine zones. Now that the system has been developed, on-going work will examine storms (e.g., Floyd) for which the freshwater discharge played a more meaningful role.

Hydrogeologic framework and simulation of shallow ground-water flow in the vicinity of a hazardous-waste landfill near Pinewood, South Carolina

USGS Publications Warehouse

Vroblesky, D.A.

1994-01-01

The geologic units in the vicinity of a hazardous- waste landfill near Pinewood, S.C., were divided into hydrogeologic units on the basis of lithologic and hydrologic characteristics. A quasi-3- dimensional finite-difference ground-water-flow model was constructed to represent the hydrogeologic flamework. The simulation results indicate that if non-reactive constituents were released to the Lang Syne water-bearing zone underlying the central and western pans of the disposal area, the constituents would move in a southwesterly direction at a rate of about one-half to 7 feet per year. Contaminants could move from the Lang Syne water-bearing zone upward to the surficial aquifer, to streams, or to Lake Marion. Although these flow rates indicate that it would require at least 50 years for contaminants to travel between the disposal area and a nearby (400 ft) potential discharge area, the heterogeneity of the site hydrogeology imparts an uncertainty to the conclusion. Faster travel times cannot be ruled out if contamination enters an area having a higher hydraulic conductivity than those determined in this investigation. Faster arrival times at Lake Marion also could result if there are pathways shorter than about 400 feet between contaminated water and an area where it can discharge to the surficial aquifer or to streams. If contaminant releases were to occur on the eastern side of the ground-water mounds, near landfill section II and the southeastern part of land fill section I, initial flow directions would be toward the water-level depression in the eastern part of the facility. Ground water within water- level depression would flow downward, probably to the underlying lower Sawdust Landing water-beating zone. Movement of non-reactive constituents in the tower Sawdust Landing water-bearing zone would be southwestward toward Lake Marion at a rate of about 8 to 20 feet per year. Transport to the lake by this route could require more than 200 years.

Geohydrology of the lower Apalachicola-Chattahoochee-Flint River basin, southwestern Georgia, northwestern Florida, and southeastern Alabama

USGS Publications Warehouse

Torak, Lynn J.; Painter, Jaime A.

2006-01-01

The lower Apalachicola-Chattahoochee-Flint (ACF) River Basin contains about 4,600 square miles of karstic and fluvial plains and nearly 100,000 cubic miles of predominantly karst limestone connected hydraulically to the principal rivers and lakes in the Coastal Plain of southwestern Georgia, northwestern Florida, and southwestern Alabama. Sediments of late-middle Eocene to Holocene in hydraulic connection with lakes, streams, and land surface comprise the surficial aquifer system, upper semiconfining unit, Upper Floridan aquifer, and lower semiconfining unit and contribute to the exchange of ground water and surface water in the stream-lake-aquifer flow system. Karst processes, hydraulic properties, and stratigraphic relations limit ground-water and surface-water interaction to the following hydrologic units of the stream-lake-aquifer flow system: the surficial aquifer system, upper semiconfining unit, Upper Floridan aquifer, and lower confining unit. Geologic units corresponding to these hydrologic units are, in ascending order: Lisbon Formation; Clinchfield Sand; Ocala, Marianna, Suwannee, and Tampa Limestones; Hawthorn Group; undifferentiated overburden (residuum); and terrace and undifferentiated (surficial) deposits. Similarities in hydraulic properties and direct or indirect interaction with surface water allow grouping sediments within these geologic units into the aforementioned hydrologic units, which transcend time-stratigraphic classifications and define the geohydrologic framework for the lower ACF River Basin. The low water-transmitting properties of the lower confining unit, principally the Lisbon Formation, allow it to act as a nearly impermeable base to the stream-lake-aquifer flow system. Hydraulic connection of the surficial aquifer system with surface water and the Upper Floridan aquifer is direct where sandy deposits overlie the limestone, or indirect where fluvial deposits overlie clayey limestone residuum. The water level in perched zones within the surficial aquifer system fluctuates independently of water-level changes in the underlying aquifer, adjacent streams, or lakes. Where the surficial aquifer system is connected with surface water and the Upper Floridan aquifer, water-table fluctuations parallel those in adjacent streams or the underlying aquifer. More...

Elevated Lead in Drinking Water in Washington, DC, 2003–2004: The Public Health Response

PubMed Central

Guidotti, Tee L.; Calhoun, Thomas; Davies-Cole, John O.; Knuckles, Maurice E.; Stokes, Lynette; Glymph, Chevelle; Lum, Garret; Moses, Marina S.; Goldsmith, David F.; Ragain, Lisa

2007-01-01

Background In 2003, residents of the District of Columbia (DC) experienced an abrupt rise in lead levels in drinking water, which followed a change in water-disinfection treatment in 2001 and which was attributed to consequent changes in water chemistry and corrosivity. Objectives To evaluate the public health implications of the exceedance, the DC Department of Health expanded the scope of its monitoring programs for blood lead levels in children. Methods From 3 February 2004 to 31 July 2004, 6,834 DC residents were screened to determine their blood lead levels. Results Children from 6 months to 6 years of age constituted 2,342 of those tested; 65 had blood lead levels > 10 μg/dL (the “level of concern” defined by the Centers for Disease Control and Prevention), the highest with a level of 68 μg/dL. Investigation of their homes identified environmental sources of lead exposure other than tap water as the source, when the source was identified. Most of the children with elevated blood lead levels (n = 46; 70.8%) lived in homes without lead drinking-water service lines, which is the principal source of lead in drinking water in older cities. Although residents of houses with lead service lines had higher blood lead levels on average than those in houses that did not, this relationship is confounded. Older houses that retain lead service lines usually have not been rehabilitated and are more likely to be associated with other sources of exposure, particularly lead paint. None of 96 pregnant women tested showed blood lead levels > 10 μg/dL, but two nursing mothers had blood lead levels > 10 μg/dL. Among two data sets of 107 and 71 children for whom paired blood and water lead levels could be obtained, there was no correlation (r2 = –0.03142 for the 107). Conclusions The expanded screening program developed in response to increased lead levels in water uncovered the true dimensions of a continuing problem with sources of lead in homes, specifically lead paint. This study cannot be used to correlate lead in drinking water with blood lead levels directly because it is based on an ecologic rather than individualized exposure assessment; the protocol for measuring lead was based on regulatory requirements rather than estimating individual intake; numerous interventions were introduced to mitigate the effect; exposure from drinking water is confounded with other sources of lead in older houses; and the period of potential exposure was limited and variable. PMID:17520055

Evaluating climatic and non-climatic stresses for declining surface water quality in Bagmati River of Nepal.

PubMed

Panthi, Jeeban; Li, Fengting; Wang, Hongtao; Aryal, Suman; Dahal, Piyush; Ghimire, Sheila; Kabenge, Martin

2017-06-01

Both climatic and non-climatic factors affect surface water quality. Similar to its effect across various sectors and areas, climate change has potential to affect surface water quality directly and indirectly. On the one hand, the rise in temperature enhances the microbial activity and decomposition of organic matter in the river system and changes in rainfall alter discharge and water flow in the river ultimately affecting pollution dilution level. On the other hand, the disposal of organic waste and channelizing municipal sewage into the rivers seriously worsen water quality. This study attempts to relate hydro-climatology, water quality, and impact of climatic and non-climatic stresses in affecting river water quality in the upper Bagmati basin in Central Nepal. The results showed that the key water quality indicators such as dissolved oxygen and chemical oxygen demand are getting worse in recent years. No significant relationships were found between the key water quality indicators and changes in key climatic variables. However, the water quality indicators correlated with the increase in urban population and per capita waste production in the city. The findings of this study indicate that dealing with non-climatic stressors such as reducing direct disposal of sewerage and other wastes in the river rather than emphasizing on working with the effects from climate change would largely help to improve water quality in the river flowing from highly populated urban areas.

Exposure to fluoridated drinking water and dental caries experience in Australian army recruits, 1996.

PubMed

Hopcraft, Matthew Scott; Morgan, Michael Vivian

2003-02-01

The purpose of this study was to investigate a group of young Australian adults to determine their caries experience and measure associations between caries experience and age, gender, socioeconomic status, education level and lifetime exposure to fluoridated water. This was achieved through a cross-sectional study involving Australian Army recruits seen for their initial dental examination on enlistment into the Australian Army. A total of 499 recruits had a clinical examination with the aid of bitewing radiographs and an orthopantomograph (OPG). Sociodemographic and fluoride exposure data were obtained via a questionnaire. This study showed that subjects with a lifetime exposure to fluoridated water reported a 23% lower level of caries experience than subjects with no exposure to fluoridated water, with a greater effect on proximal surfaces compared to smooth and occlusal surfaces. Female subjects had a level of caries experience 25% higher than male subjects, while subjects from the lowest socioeconomic background had a level of caries experience 89% times greater than subjects from the highest socioeconomic group. Although it is not possible to directly establish a causal relationship from a cross-sectional study such as this, the results from this study show a dose-response relationship which suggests that there are benefits of lifetime exposure to fluoridated drinking water through young adulthood.

Estimated 2012 groundwater potentiometric surface and drawdown from predevelopment to 2012 in the Santa Fe Group aquifer system in the Albuquerque metropolitan area, central New Mexico

USGS Publications Warehouse

Powell, Rachel I.; McKean, Sarah E.

2014-01-01

Historically, the water-supply requirements of the Albuquerque metropolitan area of central New Mexico were met almost exclusively by groundwater withdrawal from the Santa Fe Group aquifer system. In response to water-level declines, the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) began diverting water from the San Juan-Chama Drinking Water Project in December 2008 to reduce the use of groundwater to meet municipal demand. Modifications in the demand for water and the source of the supply of water for the Albuquerque metropolitan area have resulted in a variable response in the potentiometric surface of the production zone (the interval of the aquifer, from within about 200 feet below the water table to 900 feet or more, in which supply wells generally are screened) of the Santa Fe Group aquifer system. Analysis of the magnitude and spatial distribution of water-level change can help improve the understanding of how the groundwater system responds to withdrawals and variations in the management of the water supply and can support water-management agencies’ efforts to minimize future water-level declines and improve sustainability. The U.S. Geological Survey (USGS), in cooperation with the ABCWUA, has developed an estimate of the 2012 potentiometric surface of the production zone of the Santa Fe Group aquifer system in the Albuquerque metropolitan area. This potentiometric surface is the latest in a series of reports depicting the potentiometric surface of the area. This report presents the estimated potentiometric surface during winter (from December to March) of water year 2012 and the estimated changes in potentiometric surface between predevelopment (pre-1961) and water year 2012 for the production zone of the Santa Fe Group aquifer system in the Albuquerque metropolitan area. Hydrographs from selected piezometers are included to provide details of historical water-level changes. In general, water-level measurements used for this report were collected in small-diameter observation wells screened over short intervals near the middle of the production zone and were considered to best represent the potentiometric head in the production zone. The water-level measurements were collected by various local and Federal agencies. The water year 2012 potentiometric surface map was created in a geographic information system, and the change in water-level altitude from predevelopment to water year 2012 was calculated. The 2012 potentiometric surface indicates that the general direction of groundwater flow is from the Rio Grande towards clusters of supply wells in the east, north, and west. Water-level changes from predevelopment to 2012 were variable across the Albuquerque metropolitan area. Estimated drawdown from 2008 was spatially variable across the Albuquerque metropolitan area. Hydrographs from piezometers on the east side of the river indicate an increase in the annual highest water-level measurement from 2008 to 2012. Hydrographs from piezometers in the northwest part of the study area indicate either steady decline of the water-level altitude over the period of record or recently variable trends in which water-level altitudes increased for a number of years but have declined since water year 2012.

A probabilistic storm surge risk model for the German North Sea and Baltic Sea coast

NASA Astrophysics Data System (ADS)

Grabbert, Jan-Henrik; Reiner, Andreas; Deepen, Jan; Rodda, Harvey; Mai, Stephan; Pfeifer, Dietmar

2010-05-01

The German North Sea coast is highly exposed to storm surges. Due to its concave bay-like shape mainly orientated to the North-West, cyclones from Western, North-Western and Northern directions together with astronomical tide cause storm surges accumulating the water in the German bight. Due to the existence of widespread low-lying areas (below 5m above mean sea level) behind the defenses, large areas including large economic values are exposed to coastal flooding including cities like Hamburg or Bremen. The occurrence of extreme storm surges in the past like e.g. in 1962 taking about 300 lives and causing widespread flooding and 1976 raised the awareness and led to a redesign of the coastal defenses which provide a good level of protection for today's conditions. Never the less the risk of flooding exists. Moreover an amplification of storm surge risk can be expected under the influence of climate change. The Baltic Sea coast is also exposed to storm surges, which are caused by other meteorological patterns. The influence of the astronomical tide is quite low instead high water levels are induced by strong winds only. Since the exceptional extreme event in 1872 storm surge hazard has been more or less forgotten. Although such an event is very unlikely to happen, it is not impossible. Storm surge risk is currently (almost) non-insurable in Germany. The potential risk is difficult to quantify as there are almost no historical losses available. Also premiums are difficult to assess. Therefore a new storm surge risk model is being developed to provide a basis for a probabilistic quantification of potential losses from coastal inundation. The model is funded by the GDV (German Insurance Association) and is planned to be used within the German insurance sector. Results might be used for a discussion of insurance cover for storm surge. The model consists of a probabilistic event driven hazard and a vulnerability module, furthermore an exposure interface and a financial module to account for specific (re-) insurance conditions. This contribution will mainly concentrate on the hazard module. The hazard is covered by an event simulation engine enabling Monte Carlo simulations. The event generation is done on-the-fly. A classification of historical storm surges is used based on observed sea water levels at gauging stations and extended literature research. To characterize the origin of storm events and storm surges caused by those, also meteorological parameters like wind speed and wind direction are being used. If high water levels along the coast are mainly caused by strong wind from particular directions as observed at the North Sea, there is a clear empirical relationship between wind and surge (where surge is defined as the wind-driven component of the sea water level) which can be described by the ATWS (Average Transformed Wind speed). The parameters forming the load at the coastal defense elements are water level and wave parameters like significant wave height, wave period and wave direction. To assess the wave characteristics at the coast the numerical model SWAN (Simulating Waves Near Shore) from TU Delft has been used. To account for different probabilities of failure and inundation the coast is split into segments with similar defense characteristics like type of defense, height, width, orientation and others. The chosen approach covers the most relevant failure mechanisms for coastal dikes induced by wave overtopping and overflow. Dune failure is also considered in the model. Inundation of the hinterland after defense failure is modeled using a simple dynamical 2d-approach resulting in distributed water depths and flood outlines for each segment. Losses can be estimated depending on the input exposure data either coordinate based for single buildings or aggregated on postal code level using a set of depths-damage functions.

Effects of the 26 December 2004 Indian Ocean Tsunami in the Republic of Seychelles

NASA Astrophysics Data System (ADS)

Jackson, L. E.; Barrie, J. V.; Forbes, D. L.; Shaw, J.; Manson, G. K.; Schmidt, M.

2005-12-01

The Dec. 26, 2004 Indian Ocean tsunami impacted Mahé and Praslin islands as a sequence of waves at intervals of tens of minutes to hours. The first tsunami wave struck at low tide, but others occurred through several tidal cycles, so that some subsequent waves arrived at high tide. The first indication of the tsunami on the Mahé tide gauge (sampling interval 4 minutes) was a rise in water level to lower than higher high water at large tides between 08:08 and 08:12 UTC(between 12:08 and 12:12 local time). This was followed by a maximum withdrawal of water in all areas. This level was not recorded by the tide gauge at Mahé, because the stilling well went dry, but evidence from observers indicates that it dropped as much as 4 m below mean sea level. The subsequent highest water levels, highest run-ups, and maximum distances inland that tsunami flooding reached were in coastal lowlands generally facing east toward the source of the tsunami. The highest flood levels on Mahé ranged from ~1.6 m to >4.4 m above mean sea level. On Praslin, they ranged from ~1.8 m to 3.6 m. The shallow (<200 m) shelf platform surrounding the granitic islands played an important role in determining the tsunami wave direction and amplitude at the shoreline. The shoaling waves were refracted, causing them to approach the islands from various directions, and amplified so as to cause higher run-up in specific coastal embayments. Consequently, tsunami inundation and damage were not confined to east-facing shores. Run-up and damage were locally as severe along shores of Mahé and Praslin facing away from the source of the tsunami. Some observers on the west sides of both islands reported water approaching from two directions (northwest and southeast). Furthermore, the timing of maximum inundation varied around the archipelago as tsunami waves arrived at different times in the tidal cycle: the maximum inundation at Anse-à-la-Mouche (on the west side of Mahé) occurred about 4 hours after the initial tsunami wave reached the archipelago, whereas the highest water level in the city of Victoria (on the northeast side of Mahé) occurred about 16 hours after the first arrival (but with much lower wave energy). Damage to public works was greatest in the Victoria area. Lateral spread failures developed in artificial fills forming the fishing port. Liquefaction was induced in these fills by cyclic inundation, saturation and rapid draw-down. Washouts occurred on two sections of highway causeway crossing reclaimed land south of Victoria due to the rapid drainage of tsunami floodwaters. Similar erosion caused structural failure of hotel buildings on Praslin. Elsewhere, the greatest damage was coincident with preexisting modification of the coast by development including: removal of natural beach berms, construction of hotel structures adjacent to the high-water mark or seaward over the beach, and placement of roads immediately adjacent to beaches. The damaging effects of the tsunami were confined to the granitic islands of Seychelles archipelago. The lack of impact on the atolls is due to the deep water surrounding them: this resulted in minimal shoaling and amplification of the long wavelength and low-amplitude tsunami waves.

Alternative Processes for Water Reclamation and Solid Waste Processing in a Physical/chemical Bioregenerative Life Support System

NASA Technical Reports Server (NTRS)

Rogers, Tom D.

1990-01-01

Viewgraphs on alternative processes for water reclamation and solid waste processing in a physical/chemical-bioregenerative life support system are presented. The main objective is to focus attention on emerging influences of secondary factors (i.e., waste composition, type and level of chemical contaminants, and effects of microorganisms, primarily bacteria) and to constructively address these issues by discussing approaches which attack them in a direct manner.

Water resources data for California, water year 1976; Volume 1: Colorado River basin, southern Great Basin from Mexican border to Mono Lake basin, and Pacific Slope basins from Tijuana River to Santa Maria River

USGS Publications Warehouse

,

1977-01-01

Water-resources data for the 1976 water year for California consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; records of water levels in selected observation wells; and selected chemical analyses of ground water. Records for a few pertinent streamflow and water-quality stations in bordering States are also included. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of Lee R. Peterson, district chief; Winchell Smith, assistant district chief for hydrologic data; and Leonard N. Jorgensen, chief of the basic-data section. These data, a contribution to the National Water Data System, were collected by the Geological Survey and cooperating local, State, and Federal agencies in California.

Water resources data for California, water year 1977; Volume 1: Colorado River Basin, Southern Great Basin from Mexican Border to Mono Lake Basin, and Pacific Slope Basins from Tijuana River to Santa Maria River

USGS Publications Warehouse

,

1978-01-01

Water-resources data for the 1977 water year for California consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; records of water levels in selected observation wells; and selected chemical analyses of ground water. Records for a few pertinent streamflow and water-quality stations in bordering States are also included. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of Winchell Smith, Assistant District Chief for Hydrologic Data and Leonard N. Jorgensen, Chief of the Basic-Data Section. These data, a contribution to the National Water Data System, were collected by the Geological Survey and cooperating local, State, and Federal agencies in California.

Analytical optimization of demand management strategies across all urban water use sectors

NASA Astrophysics Data System (ADS)

Friedman, Kenneth; Heaney, James P.; Morales, Miguel; Palenchar, John

2014-07-01

An effective urban water demand management program can greatly influence both peak and average demand and therefore long-term water supply and infrastructure planning. Although a theoretical framework for evaluating residential indoor demand management has been well established, little has been done to evaluate other water use sectors such as residential irrigation in a compatible manner for integrating these results into an overall solution. This paper presents a systematic procedure to evaluate the optimal blend of single family residential irrigation demand management strategies to achieve a specified goal based on performance functions derived from parcel level tax assessor's data linked to customer level monthly water billing data. This framework is then generalized to apply to any urban water sector, as exponential functions can be fit to all resulting cumulative water savings functions. Two alternative formulations are presented: maximize net benefits, or minimize total costs subject to satisfying a target water savings. Explicit analytical solutions are presented for both formulations based on appropriate exponential best fits of performance functions. A direct result of this solution is the dual variable which represents the marginal cost of water saved at a specified target water savings goal. A case study of 16,303 single family irrigators in Gainesville Regional Utilities utilizing high quality tax assessor and monthly billing data along with parcel level GIS data provide an illustrative example of these techniques. Spatial clustering of targeted homes can be easily performed in GIS to identify priority demand management areas.

Systems Analyze Water Quality in Real Time

NASA Technical Reports Server (NTRS)

2010-01-01

A water analyzer developed under Small Business Innovation Research (SBIR) contracts with Kennedy Space Center now monitors treatment processes at water and wastewater facilities around the world. Originally designed to provide real-time detection of nutrient levels in hydroponic solutions for growing plants in space, the ChemScan analyzer, produced by ASA Analytics Inc., of Waukesha, Wisconsin, utilizes spectrometry and chemometric algorithms to automatically analyze multiple parameters in the water treatment process with little need for maintenance, calibration, or operator intervention. The company has experienced a compound annual growth rate of 40 percent over its 15-year history as a direct result of the technology's success.

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.

Networks of Interacting Processes: Relationships Between Drivers and Deltaic Variables to Understand Water and Sediment Transport in Wax Lake Delta, Coastal Louisiana

NASA Astrophysics Data System (ADS)

Sendrowski, A.; Passalacqua, P.; Wagner, W.; Mohrig, D. C.; Meselhe, E. A.; Sadid, K. M.; Castañeda-Moya, E.; Twilley, R.

2017-12-01

Studying distributary channel networks in river deltaic systems provides important insight into deltaic functioning and evolution. This view of networks highlights the physical connection along channels and can also encompass the structural link between channels and deltaic islands (termed structural connectivity). An alternate view of the deltaic network is one composed of interacting processes, such as relationships between external drivers (e.g., river discharge, tides, and wind) and internal deltaic response variables (e.g., water level and sediment concentration). This network, also referred to as process connectivity, is dynamic across space and time, often comprises nonlinear relationships, and contributes to the development of complex channel networks and ecologically rich island platforms. The importance of process connectivity has been acknowledged, however, few studies have directly quantified these network interactions. In this work, we quantify process connections in Wax Lake Delta (WLD), coastal Louisiana. WLD is a naturally prograding delta that serves as an analogue for river diversion projects, thus it provides an excellent setting for understanding the influence of river discharge, tides, and wind on water and sediment in a delta. Time series of water level and sediment concentration were collected in three channels from November 2013 to February 2014, while water level and turbidity were collected on an island from April 2014 to August 2015. Additionally, a model run on WLD bathymetry generated two years of sediment concentration time series in multiple channels. River discharge, tide, and wind measurements were collected from the USGS and NOAA, respectively. We analyze this data with information theory (IT), a set of statistics that measure uncertainty in signals and communication between signals. Using IT, the timescale, strength, and direction of network links are quantified by measuring the synchronization and direct influence from one variable to another. We compare channel and island process connections, which show distinct differences. Our study captures the temporal evolution of variable transport at multiple locations. While WLD is river dominated, tides and wind show unique transport signatures related to tidal spring and neap transitions and wind events.

Use of the FLUKA Monte Carlo code for 3D patient-specific dosimetry on PET-CT and SPECT-CT images*

PubMed Central

Botta, F; Mairani, A; Hobbs, R F; Vergara Gil, A; Pacilio, M; Parodi, K; Cremonesi, M; Coca Pérez, M A; Di Dia, A; Ferrari, M; Guerriero, F; Battistoni, G; Pedroli, G; Paganelli, G; Torres Aroche, L A; Sgouros, G

2014-01-01

Patient-specific absorbed dose calculation for nuclear medicine therapy is a topic of increasing interest. 3D dosimetry at the voxel level is one of the major improvements for the development of more accurate calculation techniques, as compared to the standard dosimetry at the organ level. This study aims to use the FLUKA Monte Carlo code to perform patient-specific 3D dosimetry through direct Monte Carlo simulation on PET-CT and SPECT-CT images. To this aim, dedicated routines were developed in the FLUKA environment. Two sets of simulations were performed on model and phantom images. Firstly, the correct handling of PET and SPECT images was tested under the assumption of homogeneous water medium by comparing FLUKA results with those obtained with the voxel kernel convolution method and with other Monte Carlo-based tools developed to the same purpose (the EGS-based 3D-RD software and the MCNP5-based MCID). Afterwards, the correct integration of the PET/SPECT and CT information was tested, performing direct simulations on PET/CT images for both homogeneous (water) and non-homogeneous (water with air, lung and bone inserts) phantoms. Comparison was performed with the other Monte Carlo tools performing direct simulation as well. The absorbed dose maps were compared at the voxel level. In the case of homogeneous water, by simulating 108 primary particles a 2% average difference with respect to the kernel convolution method was achieved; such difference was lower than the statistical uncertainty affecting the FLUKA results. The agreement with the other tools was within 3–4%, partially ascribable to the differences among the simulation algorithms. Including the CT-based density map, the average difference was always within 4% irrespective of the medium (water, air, bone), except for a maximum 6% value when comparing FLUKA and 3D-RD in air. The results confirmed that the routines were properly developed, opening the way for the use of FLUKA for patient-specific, image-based dosimetry in nuclear medicine. PMID:24200697

Potentiometric surface of the Upper Patapsco aquifer in southern Maryland, September 2009

USGS Publications Warehouse

Curtin, Stephen E.; Andreasen, David C.; Staley, Andrew W.

2010-01-01

This report presents a map showing the potentiometric surface of the upper Patapsco aquifer in the Patapsco Formation of Early Cretaceous age in Southern Maryland during September 2009. The map is based on water-level measurements in 65 wells. The highest measured water level was 118 feet above sea level near the northern boundary and outcrop area of the aquifer in northern Anne Arundel County. From this area, the potentiometric surface declined to the south toward a well field in the Annapolis-Arnold area, and from all directions toward three additional cones of depression. These cones are located in the Waldorf-La Plata area, Chalk Point, and the Leonardtown-Lexington Park area. The lowest measured groundwater levels were 26 feet below sea level at Annapolis, 108 feet below sea level south of Waldorf, 60 feet below sea level at Chalk Point, and 83 feet below sea level at Leonardtown. The map also shows well yield in gallons per day for 2008 at wells or well fields.

Prolonged whole body immersion in cold water: hormonal and metabolic changes.

PubMed

Smith, D J; Deuster, P A; Ryan, C J; Doubt, T J

1990-03-01

To characterize metabolic and hormonal responses during prolonged whole body immersion, 16 divers wearing dry suits completed four immersions in 5 degrees C water during each of two 5-day air saturation dives at 6.1 meters of sea water. One immersion began in the AM (1000 h) and one began in the PM (2200 h) to evaluate diurnal variations. Venous blood samples were obtained before and after completion of each immersion. Cortisol and ACTH levels demonstrated diurnal variation, with larger increases occurring after PM immersions. A greater than three-fold postimmersion increase occurred in norepinephrine (NE). There were significant increases in triiodothyronine (T3) uptake and epinephrine, but no change in T3, thyroxine, thyrotrophic hormone, and dopamine. Postimmersion free fatty acid levels increased 409% from preimmersion levels; glucose levels declined, and lactate increased significantly. Only changes in NE correlated significantly with changes in rectal temperature. In summary, when subjects are immersed in cold water for prolonged periods, with a slow rate of body cooling afforded by thermal protection and intermittent exercise, hormonal and metabolic changes occur that are similar in direction and magnitude to short-duration unprotected exposures. Except for cortisol and ACTH, none of the other measured variables exhibited diurnal alterations.

Utility of check dams in dilution of fluoride concentration in ground water and the resultant analysis of blood serum and urine of villagers, Anantapur District, Andhra Pradesh, India.

PubMed

Bhagavan, S V B K; Raghu, V

2005-02-01

High levels of fluoride (beyond 1.5 ppm) in ground water as source of drinking water are common in many parts of Andhra Pradesh, India, causing fluorosis. The study carried out in endemic Nalgonda District, Andhra Pradesh, has indicated that the fluoride-rich ground water present in the wells located down stream and close to the surface water bodies is getting diluted by the low-fluoride surface water. Encouraged by this result, check dams were constructed upstream of the identified marginally high fluoride bearing ground water zones in Anantapur District to reduce fluoride levels as an alternate solution for safe drinking water. In this paper, an attempt is made to study the utility and effect of these check dams in dilution of fluoride concentration in drinking water and its resultant impact on the health aspects of certain villagers of Anantapur District through the analysis of their blood serum and urine. Ground water samples from three fluoride-affected villages, blood and urine of males and females from the same villages were collected and analyzed for fluoride using ion selective electrode method. The results indicated that the fluoride levels in blood serum and urine of males in the age group of 5-11 years are found to be the highest. The concentration of fluoride in ground water is directly proportional to the concentration of fluoride in blood serum and urine. The concentration of fluoride in ground water with depth of the aquifer is a function of lithology, amount and duration of rainfall, rate of infiltration, level of ground water exploitation in the area etc. The construction of check dams upstream of the identified marginally high fluoride waters will not only cause additional recharge of ground water but also reduces the fluoride concentration eventually improving the health of the villagers.

Numerical Simulation of Ground-Water Flow and Assessment of the Effects of Artificial Recharge in the Rialto-Colton Basin, San Bernardino County, California

USGS Publications Warehouse

Woolfenden, Linda R.; Koczot, Kathryn M.

2001-01-01

The Rialto?Colton Basin, in western San Bernardino County, California, was chosen for storage of imported water because of the good quality of native ground water, the known storage capacity for additional ground-water storage in the basin, and the availability of imported water. To supplement native ground-water resources and offset overdraft conditions in the basin during dry periods, artificial-recharge operations during wet periods in the Rialto?Colton Basin were begun in 1982 to store surplus imported water. Local water purveyors recognized that determining the movement and ultimate disposition of the artificially recharged imported water would require a better understanding of the ground-water flow system. In this study, a finite-difference model was used to simulate ground-water flow in the Rialto?Colton Basin to gain a better understanding of the ground-water flow system and to evaluate the hydraulic effects of artificial recharge of imported water. The ground-water basin was simulated as four horizontal layers representing the river- channel deposits and the upper, middle, and lower water-bearing units. Several flow barriers bordering and internal to the Rialto?Colton Basin influence the direction of ground-water flow. Ground water may flow relatively unrestricted in the shallow parts of the flow system; however, the faults generally become more restrictive at depth. A particle-tracking model was used to simulate advective transport of imported water within the ground-water flow system and to evaluate three artificial-recharge alternatives. The ground-water flow model was calibrated to transient conditions for 1945?96. Initial conditions for the transient-state simulation were established by using 1945 recharge and discharge rates, and assuming no change in storage in the basin. Average hydrologic conditions for 1945?96 were used for the predictive simulations (1997?2027). Ground-water-level measurements made during 1945 were used for comparison with the initial-conditions simulation to determine if there was a reasonable match, and thus reasonable starting heads, for the transient simulation. The comparison between simulated head and measured water levels indicates that, overall, the simulated heads match measured water levels well; the goodness-of-fit value is 0.99. The largest differences between simulated head and measured water level occurred between Barrier H and the Rialto?Colton Fault. Simulated heads near the Santa Ana River and Warm Creek, and simulated heads northwest of Barrier J, generally are within 30 feet of measured water levels and five are within 20 feet. Model-simulated heads were compared with measured long-term changes in hydrographs of composite water levels in selected wells, and with measured short-term changes in hydrographs of water levels in multiple-depth observation wells installed for this project. Simulated hydraulic heads generally matched measured water levels in wells northwest of Barrier J (in the northwestern part of the basin) and in the central part of the basin during 1945?96. In addition, the model adequately simulated water levels in the southeastern part of the basin near the Santa Ana River and Warm Creek and east of an unnamed fault that subparallels the San Jacinto Fault. Simulated heads and measured water levels in the central part of the basin generally are within 10 feet until about 1982?85 when differences become greater. In the northwestern part of the basin southeast of Barrier J, simulated heads were as much as 50 feet higher than measured water levels during 1945?82 but matched measured water levels well after 1982. In the compartment between Barrier H and the Rialto?Colton Fault, simulated heads match well during 1945?82 but are comparatively low during 1982?96. Near the Santa Ana River and Warm Creek, simulated heads generally rose above measured water levels except during 1965?72 when simulated heads compared well with measured water levels. Average

The U.S. Geological Survey and City of Atlanta water-quality and water-quantity monitoring network

USGS Publications Warehouse

Horowitz, Arthur J.; Hughes, W. Brian

2006-01-01

Population growth and urbanization affect the landscape, and the quality and quantity of water in nearby rivers and streams, as well as downstream receiving waters (Ellis, 1999). Typical impacts include: (1) disruption of the hydrologic cycle through increases in the extent of impervious surfaces (e.g., roads, roofs, sidewalks) that increase the velocity and volume of surface-water runoff; (2) increased chemical loads to local and downstream receiving waters from industrial sources, nonpoint-source runoff, leaking sewer systems, and sewer overflows; (3) direct or indirect soil contamination from industrial sources, power-generating facilities, and landfills; and (4) reduction in the quantity and quality of aquatic habitats. The City of Atlanta's monitoring network consists of 21 long-term sites. Eleven of these are 'fully instrumented' to provide real-time data on water temperature, pH, specific conductance, dissolved oxygen, turbidity (intended as a surrogate for suspended sediment concentration), water level (gage height, intended as a surrogate for discharge), and precipitation. Data are transmitted hourly and are available on a public Web site (http://ga.water.usgs.gov/). Two sites only measure water level and rainfall as an aid to stormwater monitoring. The eight remaining sites are used to assess water quality.

Wastewater application by spray irrigation on a field southeast of Tallahassee, Florida; effects on ground-water quality and quantity, 1980-82

USGS Publications Warehouse

Elder, J.F.; Hunn, J.D.; Calhoun, C.W.

1985-01-01

A field southeast of Tallahassee, Florida, used for land application of wastewater by spray irrigation was the site of a ground-water monitoring study to determine effects of spray irrigation on water-table elevations and ground-water quality. The study was conducted during 1980-82 in cooperation with the City of Tallahassee. The wastewater has relatively high concentrations of chloride, nitrogen, phosphorus, organic carbon , coliform bacteria, sodium, and potassium. These substances are usually attenuated before they can impact the ground water. However, increases in chloride and nitrate-nitrogen were evident in ground water in some of the monitoring wells during the study. Chloride concentrations increased five-fold or more in some wells directly affected by spray irrigation, and nitrate-nitrogen concentrations increased eight-fold or more. Ground-water levels in the area of the spray field fluctuated over a range of several feet. These fluctuations were affected somewhat by spray irrigation, but the primary control on water levels was rainfall. As of December 1982, constituents introduced to the system by spray irrigation of effluent had not exceeded drinking water standard in the ground water. However, the system had not yet stabilized and more changes in ground-water quality could be expected. (USGS)

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.

Correlation between Fluoride in Drinking Water and Its Levels in Breast Milk in Golestan Province, Northern Iran.

PubMed

Faraji, Hossein; Mohammadi, Ali Akbar; Akbari-Adergani, Behrouz; Vakili Saatloo, Naimeh; Lashkarboloki, Gholamreza; Mahvi, Amir Hossein

2014-12-01

Fluoride is an essential element for human health. However, excess fluoride in drinking water may cause dental and/or skeletal fluorosis. Drinking water is the main route of fluoride intake. The aim of the present study was to measure fluoride levels in human breast milk collected from two regions of Golestan Province, northern Iran with different amount of fluoride concentration of drinking water in Bandar Gaz and Nokande cities and to correlate it with fluoride concentrations in drinking water used by mothers living in these two areas. Twenty samples of water were collected from seven drinking water wells during 2012 from Bandar Gaz and Nokande in Iran during 2012. Fluoride concentration of water samples was measured using SPADNS method. Sixty breast milk samples were collected from lactating mothers of Bandar Gaz and Nokande cities. Content in breast milk was determined using standard F ion-selective electrode. Spearman's rho correlation analysis was used to assess any possible relationship between fluoride levels in breast milk and in drinking water. The means and standard deviation for F concentration in breast milk and drinking water were 0.002188±0.00026224 ppm and 0.5850±0.22542 ppm, respectively. Analysis of data showed that the variables were not normally distributed so the Spearman correlation coefficient between two variables calculated (ρ S = 0.65) and it was significant (P=0.002). Fluoride concentration in water can directly act on its concentration in breast milk. We speculate that modifying F concentration in water can affect accessibility of fluoride for infants.

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

Correlation between Fluoride in Drinking Water and Its Levels in Breast Milk in Golestan Province, Northern Iran

PubMed Central

FARAJI, Hossein; MOHAMMADI, Ali Akbar; AKBARI-ADERGANI, Behrouz; VAKILI SAATLOO, Naimeh; LASHKARBOLOKI, Gholamreza; MAHVI, Amir Hossein

2014-01-01

Background: Fluoride is an essential element for human health. However, excess fluoride in drinking water may cause dental and/or skeletal fluorosis. Drinking water is the main route of fluoride intake. The aim of the present study was to measure fluoride levels in human breast milk collected from two regions of Golestan Province, northern Iran with different amount of fluoride concentration of drinking water in Bandar Gaz and Nokande cities and to correlate it with fluoride concentrations in drinking water used by mothers living in these two areas. Methods: Twenty samples of water were collected from seven drinking water wells during 2012 from Bandar Gaz and Nokande in Iran during 2012. Fluoride concentration of water samples was measured using SPADNS method. Sixty breast milk samples were collected from lactating mothers of Bandar Gaz and Nokande cities. Content in breast milk was determined using standard F ion-selective electrode. Spearman’s rho correlation analysis was used to assess any possible relationship between fluoride levels in breast milk and in drinking water. Results: The means and standard deviation for F concentration in breast milk and drinking water were 0.002188±0.00026224 ppm and 0.5850±0.22542 ppm, respectively. Analysis of data showed that the variables were not normally distributed so the Spearman correlation coefficient between two variables calculated (ρS = 0.65) and it was significant (P=0.002). Conclusion: Fluoride concentration in water can directly act on its concentration in breast milk. We speculate that modifying F concentration in water can affect accessibility of fluoride for infants. PMID:26171359

Farmers' preferences for water policy reforms: Results from a survey in Alberta

NASA Astrophysics Data System (ADS)

Zhang, W.; Bjornlund, H.; Klein, K.

2012-12-01

Facing increasingly urgent stress on global water scarcity, many reforms have been launched in countries around the world. As the biggest group of natural resource managers, farmers' behaviour is drawing increasingly wide attention. Satisfying new demands for water will depend on farmers' support since, generally, water will need to be transferred from farmers who have historically secure rights. Although water pricing reform is widely considered to lead to water conservation, the uncertainty of its potential impacts hinders the process of reform. This farmer-level empirical research explores farmers' possible responses to introduction of reforms in water pricing. A survey was conducted of about 300 farm households that use water for irrigating crops in Southern Alberta, an area that is facing water shortages and has had to stop issuing new water licences. By using structural equation modelling, the strength and direction of direct and indirect relationships between external, internal and behavioural variables as proposed in general attitude theory have been estimated. Farming as a family engagement, family members' and family unit's characteristics doubtlessly affect farming practice and farm decisions. Farmers' behaviour was explored under the family and farm context. In developing and testing conceptual models that integrate socio-demographic, psychological, farming context and social milieu factors, we may develop a deeper understanding of farmers' behaviour. The findings and recommendations will be beneficial for environmental practitioners and policy makers.

Village-Level Identification of Nitrate Sources: Collaboration of Experts and Local Population in Benin, Africa

NASA Astrophysics Data System (ADS)

Crane, P.; Silliman, S. E.; Boukari, M.; Atoro, I.; Azonsi, F.

2005-12-01

Deteriorating groundwater quality, as represented by high nitrates, in the Colline province of Benin, West Africa was identified by the Benin national water agency, Direction Hydraulique. For unknown reasons the Colline province had consistently higher nitrate levels than any other region of the country. In an effort to address this water quality issue, a collaborative team was created that incorporated professionals from the Universite d'Abomey-Calavi (Benin), the University of Notre Dame (USA), Direction l'Hydraulique (a government water agency in Benin), Centre Afrika Obota (an educational NGO in Benin), and the local population of the village of Adourekoman. The goals of the project were to: (i) identify the source of nitrates, (ii) test field techniques for long term, local monitoring, and (iii) identify possible solutions to the high levels of groundwater nitrates. In order to accomplish these goals, the following methods were utilized: regional sampling of groundwater quality, field methods that allowed the local population to regularly monitor village groundwater quality, isotopic analysis, and sociological methods of surveys, focus groups, and observations. It is through the combination of these multi-disciplinary methods that all three goals were successfully addressed leading to preliminary identification of the sources of nitrates in the village of Adourekoman, confirmation of utility of field techniques, and initial assessment of possible solutions to the contamination problem.

Is alpha-V 2O 5 a cathode material for Mg insertion batteries?

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

Sa, Niya; Wang, Hao; Proffit, Danielle L.

When designing a high energy density battery, one of the critical features is a high voltage, high capacity cathode material. In the development of Mg batteries, oxide cathodes that can reversibly intercalate Mg, while at the same time being compatible with an electrolyte that can deposit Mg reversibly are rare. Herein, we report the compatibility of Mg anodes with a-V 2O 5 by employing magnesium bis(trifluoromethane sulfonyl)imide in diglyme electrolytes at very low water levels. Electrolytes that contain a high water level do not reversibly deposit Mg, but interestingly these electrolytes appear to enable much higher capacities for an a-Vmore » 2O 5 cathode. Solid state NMR indicates that the major source of the higher capacity in high water content electrolytes originates from reversible proton insertion. In contrast, we found that lowering the water level of the magnesium bis(trifluoromethane sulfonyl)imide in diglyme electrolyte is critical to achieve reversible Mg deposition and direct evidence for reversible Mg intercalation is shown. Findings we report here elucidate the role of proton intercalation in water-containing electrolytes and clarify numerous conflicting reports of Mg insertion into a-V 2O 5.« less

Dynamic fuzzy modeling of storm water infiltration in urban fractured aquifers

USGS Publications Warehouse

Hong, Y.-S.; Rosen, Michael R.; Reeves, R.R.

2002-01-01

In an urban fractured-rock aquifer in the Mt. Eden area of Auckland, New Zealand, disposal of storm water is via "soakholes" drilled directly into the top of the fractured basalt rock. The dynamic response of the groundwater level due to the storm water infiltration shows characteristics of a strongly time-varying system. A dynamic fuzzy modeling approach, which is based on multiple local models that are weighted using fuzzy membership functions, has been developed to identify and predict groundwater level fluctuations caused by storm water infiltration. The dynamic fuzzy model is initialized by the fuzzy clustering algorithm and optimized by the gradient-descent algorithm in order to effectively derive the multiple local models-each of which is associated with a locally valid model that represents the groundwater level state as a response to different intensities of rainfall events. The results have shown that even if the number of fuzzy local models derived is small, the fuzzy modeling approach developed provides good prediction results despite the highly time-varying nature of this urban fractured-rock aquifer system. Further, it allows interpretable representations of the dynamic behavior of the groundwater system due to storm water infiltration.

Geohydrology and Numerical Simulation of the Ground-Water Flow System of Kona, Island of Hawaii

USGS Publications Warehouse

Oki, Delwyn S.

1999-01-01

Prior to the early 1990's, ground-water in the Kona area, which is in the western part of the island of Hawaii, was withdrawn from wells located within about 3 mi from the coast where water levels were less than 10 feet above sea level. In 1990, exploratory drilling in the uplands east of the existing coastal wells first revealed the presence of high water levels (greater than 40 feet above sea level) in the Kona area. Measured water levels from 16 wells indicate that high water levels exist in a zone parallel to and inland of the Kona coast, between Kalaoa and Honaunau. Available hydrologic and geophysical evidence is generally consistent with the concept that the high ground-water levels are associated with a buried dike complex. A two-dimensional (areal), steady-state, freshwater-saltwater, sharp-interface ground-water flow model was developed for the Kona area of the island of Hawaii, to enhance the understanding of (1) the distribution of aquifer hydraulic properties, (2) the conceptual framework of the ground-water flow system, and (3) the regional effects of ground-water withdrawals on water levels and coastal discharge. The model uses the finite-difference code SHARP. To estimate the hydraulic characteristics, average recharge, withdrawals, and water-level conditions for the period 1991-93 were simulated. The following horizontal hydraulic-conductivity values were estimated: (1) 7,500 feet per day for the dike-free volcanic rocks of Hualalai and Mauna Loa, (2) 0.1 feet per day for the buried dike complex of Hualalai, (3) 10 feet per day for the northern marginal dike zone (north of Kalaoa), and (4) 0.5 feet per day for the southern marginal dike zone between Palani Junction and Holualoa. The coastal leakance was estimated to be 0.05 feet per day per foot. Measured water levels indicate that ground water generally flows from inland areas to the coast. Model results are in general agreement with the limited set of measured water levels in the Kona area. Model results indicate, however, that water levels do not strictly increase in an inland direction and that a ground-water divide exists within the buried dike complex. Data are not available, however, to verify model results in the area near and inland of the model-calculated ground-water divide. Three simulations to determine the effects of proposed withdrawals from the high water-level area on coastal discharge and water levels, relative to model-calculated, steady-state coastal discharge and water levels for 1997 withdrawal rates, show that the effects are widespread. During 1997, the total withdrawal of ground water from the high water-level area between Palani Junction and Holualoa was about 1 million gallons per day. Model results indicate that it may not be possible to withdraw 25.6 million gallons per day of freshwater from this area between Palani Junction and Holualoa, but that it may be possible to withdraw between 5 to 8 million gallons per day from the same area. For a proposed withdrawal rate of 5.0 million gallons per day uniformly distributed to 12 sites between Palani Junction and Holualoa, the model-calculated drawdown of 0.01 foot or more extends about 9 miles north-northwest and about 7 miles south of the proposed well sites. In all scenarios, freshwater coastal discharge is reduced by an amount equal to the additional freshwater withdrawal. Additional data needed to improve the understanding of the ground-water flow system in the Kona area include: (1) a wider spatial distribution and longer temporal distribution of water levels, (2) improved information about the subsurface geology, (3) independent estimates of hydraulic conductivity, (4) improved recharge estimates, and (5) information about the vertical distribution of salinity in ground water.

Implementation of the EU-policy framework WFD and GWD in Europe - Activities of CIS Working Group Groundwater

NASA Astrophysics Data System (ADS)

Grath, Johannes; Ward, Rob; Hall, Anna

2013-04-01

At the European level, the basic elements for groundwater management and protection are laid down in the Water Framework Directive (WFD) (2000/60/EC) and the Groundwater Daughter Directive (2006/118/EC). EU Member States, Norway and the European Commission (EC) have jointly developed a common strategy for supporting the implementation of the WFD. The main aim of this Common Implementation Strategy (CIS) is to ensure the coherent and harmonious implementation of the directives through the clarification of a number of methodological questions enabling a common understanding to be reached on the technical and scientific implications of the WFD (European Communities, 2008). Groundwater specific issues are dealt with in Working Group C Groundwater. Members of the working group are experts nominated by Member states, Norway, Switzerland and Accession Countries (from administrative bodies, research institutes, …) and representatives from relevant stakeholders and NGOs. Working Group C Groundwater has produced numerous guidance documents and technical reports that have been endorsed by EU Water Directors to support and enable Member States to implement the directives. All the documents are published by the EC. Access is available via the following link: http://ec.europa.eu/environment/water/water-framework/groundwater/activities.htm Having addressed implementations issues during the 1st river basin planning cycle, WG C Groundwater is currently focussing on the following issues: groundwater dependent ecosystems, and climate change and groundwater. In the future, the outcome and recommendations of the "Blueprint" - to safeguard Europe's water resources - which was recently published by the EC will be of utmost importance in setting the agenda for the group. Most likely this will include water pricing, water demand management and water abstraction. Complementory to the particular working groups, a Science Policy Interface (SPI) activity has been established. Its purpose is to improve dialogue and linkages between the scientific and policy-making communities to enhance the accessibility of scientific knowledge to policy makers, to deliver more policy-relevant research outcomes and enable future research priorities to be identified. References: European Communities (2008): Groundwater Protection in Europe, The new Groundwater Directive - Consolidating the EU Regulatory Framework

BOD and DO Identification of Jeneberrang-River Water as Water Source

NASA Astrophysics Data System (ADS)

Basir, Basir; Haris, Ibrahim Abdul

2018-05-01

Water is a part of life on the surface of the earth. It is not a new substance which no life on earth can survive without water. This study aims to identify the quality of river water of jeneberang as municipal waterworks (PDAM) raw regarding to turbidity parameters, BOD, and DO. The used methodology is observational with descriptive approach. The sampling technique was done by grasping each sample for turbidity parameter, BOD and DO in four IPAM water inlet of Makassar City. This sampling was conducted at Laboratory of Environmental Health Engineering Center (BTKL) and Disease Control using Nephelometric Turbidity Unit, Titrimetry, and Spectrophotometric method. The results of the examination showed that the turbidity level> 5 NTU, so it is not eligible to be drunk directly. The levels for BOD and eligibles for not exceeding the specified limits are <3 mg / l and <25 mg / l and in DO for Maccini Sombala <4 mg / l region, so it is not eligible. The conclusion in this research that turbidity parameter, BOD and DO qualify as the raw water of PDAM have to be processed so that water can be drunk by society.

Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, May 2007

USGS Publications Warehouse

Kinnaman, Sandra L.; Dixon, Joann F.

2007-01-01

Introduction This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 2007. Potentiometric contours are based on water-level measurements collected at 566 wells during the period May 4-June 11 near the end of the dry season, however most of the water level data for this map were collected by the U.S. Geological Survey during the period May 21-25, 2007. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

Role of Hot Water System Design on Factors Influential to Pathogen Regrowth: Temperature, Chlorine Residual, Hydrogen Evolution, and Sediment

PubMed Central

Brazeau, Randi H.; Edwards, Marc A.

2013-01-01

Abstract Residential water heating is linked to growth of pathogens in premise plumbing, which is the primary source of waterborne disease in the United States. Temperature and disinfectant residual are critical factors controlling increased concentration of pathogens, but understanding of how each factor varies in different water heater configurations is lacking. A direct comparative study of electric water heater systems was conducted to evaluate temporal variations in temperature and water quality parameters including dissolved oxygen levels, hydrogen evolution, total and soluble metal concentrations, and disinfectant decay. Recirculation tanks had much greater volumes of water at temperature ranges with potential for increased pathogen growth when set at 49°C compared with standard tank systems without recirculation. In contrast, when set at the higher end of acceptable ranges (i.e., 60°C), this relationship was reversed and recirculation systems had less volume of water at risk for pathogen growth compared with conventional systems. Recirculation tanks also tended to have much lower levels of disinfectant residual (standard systems had 40–600% higher residual), 4–6 times as much hydrogen, and 3–20 times more sediment compared with standard tanks without recirculation. On demand tankless systems had very small volumes of water at risk and relatively high levels of disinfectant residual. Recirculation systems may have distinct advantages in controlling pathogens via thermal disinfection if set at 60°C, but these systems have lower levels of disinfectant residual and greater volumes at risk if set at lower temperatures. PMID:24170969

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

USGS Publications Warehouse

Bradley, Michael W.; Hileman, Gregg Edward

2006-01-01

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

A novel use of the caesium-137 technique to estimate human interference and historical water level in a Mediterranean Temporary Pond.

PubMed

Foteinis, Spyros; Mpizoura, Katerina; Panagopoulos, Giorgos; Chatzisymeon, Efthalia; Kallithrakas-Kontos, Nikolaos; Manutsoglu, Emmanouil

2014-01-01

The sustainability of, and the effects of human pressures on, Omalos Mediterranean Temporary Pond (MTP), Chanea, Greece was assessed. The (137)Cs technique was used to identify alleged anthropogenic interference (excavation) in the studied area. It was found that about one third of the ponds bed surface material had been removed and disposed of on the northeast edge, confirming unplanned excavations that took place in the MTP area some years ago. Nonetheless, five years after the excavation, the MTP's ecosystem (flora and fauna) had recovered, which indicates that these small ecosystems are resilient to direct human pressures, like excavations. Moreover, with the (137)Cs technique it was possible to identify the historical water level of Omalos MTP, when the fallout from the Chernobyl accident reached this area, in May of 1986. Therefore, the (137)Cs technique can be useful in the identification of the historical water level of small MTPs and other ephemeral water bodies. Applications include the verification and validation of hydrological models. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modeling of Cr contamination in the agricultural lands of three villages near the leather industry in Kasur, Pakistan, using statistical and GIS techniques.

PubMed

Shafiq, Muhammad; Shaukat, Tahira; Nazir, Aisha; Bareen, Firdaus-E-

2017-08-01

Kasur is one of the hubs of leather industry in the Punjab, Pakistan, where chrome tanning method of leather processing is extensively being used. Chromium (Cr) accumulation levels in the irrigation water, soil, and seasonal vegetables were studied in three villages located in the vicinity of wastewater treatment plant and solid waste dumping site operated by the Kasur Tanneries Waste Management Agency (KTWMA). The data was interpreted using analysis of variance (ANOVA), clustering analysis (CA), and principal component analysis (PCA). Interpolated surface maps for Cr were generated using the actual data obtained for the 30 sampling sites in each of the three villages for irrigation water, soil, and seasonal vegetables. The level of contamination in the three villages was directly proportional to their distance from KTWMA wastewater treatment plant and the direction of water runoff. The highest level of Cr contamination in soil (mg kg -1 ) was observed at Faqeeria Wala (37.67), intermediate at Dollay Wala (30.33), and the least in Maan (25.16). A gradational variation in Cr accumulation was observed in the three villages from contaminated wastewater having the least contamination level (2.02-4.40 mg L -1 ), to soil (25.16-37.67 mg kg -1 ), and ultimately in the seasonal vegetable crops (156.67-248.33 mg kg -1 ) cultivated in the region, having the highest level of Cr contamination above the permissible limit. The model used not only predicted the current situation of Cr contamination in the three villages but also indicated the trend of magnification of Cr contamination from irrigation water to soil and to the base of the food chain. Among the multiple causes of Cr contamination of vegetables, soil irrigation with contaminated groundwater was observed to be the dominant one.

Water resources of Sedgwick County, Kansas

USGS Publications Warehouse

Bevans, H.E.

1989-01-01

Hydrologic data from streams, impoundments, and wells are interpreted to: (1) document water resources characteristics; (2) describe causes and extent of changes in water resources characteristics; and (3) evaluate water resources as sources of supply. During 1985, about 134,200 acre-ft of water (84% groundwater) were used for public (42%), irrigation, (40%), industrial (14%), and domestic (4%) supplies. Streamflow and groundwater levels are related directly to precipitation, and major rivers are sustained by groundwater inflow. Significant groundwater level declines have occurred only in the Wichita well field. The Arkansas and Ninnescah Rivers have sodium chloride type water; the Little Arkansas River, calcium bicarbonate type water. Water quality characteristics of water in small streams and wells depend primarily on local geology. The Wellington Formation commonly yields calcium sulfate type water; Ninnescah Shale and unconsolidated deposits generally yield calcium bicarbonate type water. Sodium chloride and calcium sulfate type water in the area often have dissolved-solids concentrations exceeding 1,000 mg/L. Water contamination by treated sewage effluent was detected inparts of the Arkansas River, Little Arkansas River, and Cowskin Creek. Nitrite plus nitrate as nitrogen contamination was detected in 11 of 101 wells; oilfield brine was detected in the Wichita-Valley Center Floodway, Prairie Creek, Whitewater Creek, and 16 of 101 wells; and agricultural pesticides were detected in 8 of 14 impoundments and 5 of 19 wells. Generally, the water is acceptable for most uses. (USGS)

OBIA based hierarchical image classification for industrial lake water.

PubMed

Uca Avci, Z D; Karaman, M; Ozelkan, E; Kumral, M; Budakoglu, M

2014-07-15

Water management is very important in water mining regions for the sustainability of the natural environment and for industrial activities. This study focused on Acigol Lake, which is an important wetland for sodium sulphate (Na2SO4) production, a significant natural protection area and habitat for local bird species and endemic species of this saline environment, and a stopover for migrating flamingos. By a hierarchical classification method, ponds representing the industrial part were classified according to in-situ measured Baumé values, and lake water representing the natural part was classified according to in-situ measurements of water depth. The latter is directly related to the water level, which should not exceed a critical level determined by the regulatory authorities. The resulting data, produced at an accuracy of around 80%, illustrates the status in two main regions for a single date. The output of the analysis may be meaningful for firms and environmental researchers, and authorizations can provide a good perspective for decision making for sustainable resource management in the region which has uncommon and specific ecological characteristics. Copyright © 2014 Elsevier B.V. All rights reserved.

The influence of environmental conditions on lead transfer from spent gunshot to sediments and water: Other routes for Pb poisoning.

PubMed

Binkowski, Łukasz J

2017-11-01

Lead (Pb) from spent gunshot and fishing sinkers is recognized as the main source of Pb poisoning among waterfowl. It is also suspected to directly pollute water and sediments, but no appropriate, comprehensive evaluation of this issue has so far been carried out. An experiment on Pb pellets in microcosms (n = 160) with two sediment types (mud and gravel), three water pH values (4, 7 and 9) and two wind levels (wind and windless simulation) was therefore run. Substantial differences in Pb transfer (measured with ICP-OES) between sediment types and pH levels of water were observed. Simulated wind conditions were a significant factor only for some variables and circumstances. The strongest Pb deposit to water and sediments occurred in mud microcosms with water of pH value of 4. Median pellet erosion during the experiment differed little between sediment types. The experiment revealed that Pb transfer from spent gunshot to the environment occurs only in specific environmental conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Potentiometric surface of the Upper Floridan aquifer in the Ichetucknee springshed and vicinity, northern Florida, September 2003

USGS Publications Warehouse

Sepulveda, A. Alejandro; Katz, Brian G.; Mahon, Gary L.

2006-01-01

The Upper Floridan aquifer is a highly permeable unit of carbonate rock extending beneath most of Florida and parts of southern Alabama, Georgia, and South Carolina. The high permeability is due in a large part to the widening of fractures that developed over time and the formation of conduits within the aquifer through dissolution of the limestone. This process has also produced numerous karst features such as springs, sinking streams, and sinkholes in northern Florida. These dissolution features, whether expressed at the surface or not, greatly influence the direction of ground-water flow in the Ichetucknee springshed adjacent to the Ichetucknee River. Ground water generally flows southwestward in the springshed and discharges to the Ichetucknee or Santa Fe Rivers, or to the springs along those rivers. This map depicts the September 9-10, 2003, potentiometric surface of the Upper Floridan aquifer based on 94 water-level measurements made by the Suwannee River Water Management District. Ground-water levels in this watershed fluctuate in response to precipitation and due to the high degree of interconnection between the surface-water system and the aquifer.

Earth-atmosphere system and surface reflectivities in arid regions from LANDSAT multispectral scanner measurements

NASA Technical Reports Server (NTRS)

Otterman, J.; Fraser, R. S.

1976-01-01

Programs for computing atmospheric transmission and scattering solar radiation were used to compute the ratios of the Earth-atmosphere system (space) directional reflectivities in the vertical direction to the surface reflectivity, for the four bands of the LANDSAT multispectral scanner (MSS). These ratios are presented as graphs for two water vapor levels, as a function of the surface reflectivity, for various sun elevation angles. Space directional reflectivities in the vertical direction are reported for selected arid regions in Asia, Africa and Central America from the spectral radiance levels measured by the LANDSAT MSS. From these space reflectivities, surface vertical reflectivities were computed applying the pertinent graphs. These surface reflectivities were used to estimate the surface albedo for the entire solar spectrum. The estimated albedos are in the range 0.34-0.52, higher than the values reported by most previous researchers from space measurements, but are consistent with laboratory measurements.

Bathroom Buddies: Countering your Clockwise Rotation

NASA Astrophysics Data System (ADS)

Cooper, C. M.; Stegman, D. R.

2006-12-01

Which way does your bathtub, toilet, sink, or other favorite plumbing basin drain? Popular television shows perpetuate the fact that water spins the opposite direction in the southern hemisphere, and sometimes even explicitly point to the Coriolis effect (or Earth's rotation) as the cause. Skeptics disagree: "No way. Water doesn't obey your rules: it goes where it wants...like me, babe." [1]. Fact: Cyclones rotate clockwise in the southern hemisphere and hurricanes counter-clockwise in the northern hemisphere. But does your hemisphere also determine the direction water spirals down your toilet? In the ideal scenario of water draining out a sink (i.e. a defect-free, perfectly-leveled basin in which water has remained undisturbed for sufficient enough time to quiet any background motions or eddies) --- then yes, maybe it is possible. However, in everyday life, not even the most decadent of bathtubs provide us a large enough lengthscale to observe the Coriolis effect on the direction which water spirals towards the drain. Thus, we are left confronting the possibility that something heard on television isn't true. But is just "telling" students, friends, or strangers in bars enough to debunk this urban myth? Rather, we offer a practical demonstration involving a friend from the opposite hemisphere (if not one in existence, then find one on the internet!), a bathroom, a funnel, a bucket, some food coloring, a camera, a pitcher and some equations and scalings for extra credit and fun. 1) Simpson, B., "Bart vs. Australia", Season 6, Episode 119, 1995.

Nest survival of American Coots relative to grazing, burning, and water depths

USGS Publications Warehouse

Austin, Jane E.; Buhl, Deborah A.

2011-01-01

Water and emergent vegetation are key features influencing nest site selection and success for many marsh-nesting waterbirds. Wetland management practices such as grazing, burning, and water-level manipulations directly affect these features and can influence nest survival. We used model selection and before-after-control-impact approaches to evaluate the effects of water depth and four common land-management practices or treatments, i.e., summer grazing, fall grazing, fall burning, and idle (no active treatment) on nest survival of American coots (Fulica americana) nesting at Grays Lake, a large montane wetland in southeast Idaho. The best model included the variables year × treatment, and quadratic functions of date, water depth, and nest age; height of vegetation at the nest did not improve the best model. However, results from the before-after-control-impact analysis indicate that management practices affected nest success via vegetation and involved interactions of hydrology, residual vegetation, and habitat composition. Nest success in idled fields changed little between pre- and post-treatment periods, whereas nest success declined in fields that were grazed or burned, with the most dramatic declines the year following treatments. The importance of water depth may be amplified in this wetland system because of rapid water-level withdrawal during the nesting season. Water and land-use values for area ranchers, management for nesting waterbirds, and long-term wetland function are important considerations in management of water levels and vegetation.

Leachate water quality from soils amended with swine manure based biochars

USDA-ARS?s Scientific Manuscript database

In the face of the rising level of manure production from concentrated animal feeding operations (CAFOs), management options are being sought that can provide nutrient recycling for plant growth and improved soil conditions with minimal environmental impacts. Alternatives to direct manure applicatio...

Comparison of methods for the concentration of suspended sediment in river water for subsequent chemical analysis

USGS Publications Warehouse

Horowltz, A.J.

1986-01-01

Centrifugation, settling/centrifugation, and backflush-filtration procedures have been tested for the concentration of suspended sediment from water for subsequent trace-metal analysis. Either of the first two procedures is comparable with in-line filtration and can be carried out precisely, accurately, and with a facility that makes the procedures amenable to large-scale sampling and analysis programs. There is less potential for post-sampling alteration of suspended sediment-associated metal concentrations with the centrifugation procedure because sample stabilization is accomplished more rapidly than with settling/centrifugation. Sample preservation can be achieved by chilling. Suspended sediment associated metal levels can best be determined by direct analysis but can also be estimated from the difference between a set of unfiltered-digested and filtered subsamples. However, when suspended sediment concentrations (<150 mg/L) or trace-metal levels are low, the direct analysis approach makes quantitation more accurate and precise and can be accomplished with simpler analytical procedures.

Field tests of 2- and 40-tube condensers at the East Mesa Geothermal Test Site

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

Murphy, R.W.; Domingo, N.

1982-05-01

Two water-cooled isobutane condensers, one with 2 tubes and one with 40 tubes, were subjected to field tests at the East Mesa Geothermal Test Site to assess relative heat transfer performance in both surface evaporator and direct-contact evaporator modes. The five groups of tests established that field performance was below earlier laboratory-determined levels and that direct-contact evaporator mode performance was poorer than that for the surface evaporator mode. In all test situations, fluted condenser tubes performed better than smooth condenser tubes. Cooling water quality had no significant effect on performance, but brine preflash in the direct-contact mode did promote somemore » relative performance improvement. Important implications of these results for binary geothermal power plants are that (1) working-fluid-side impurities can significantly degrade heat transfer performance of the power plant condensers and (2) provisions for minimizing such impurities may be required.« less

Direct chemiluminescence of carbon dots induced by potassium ferricyanide and its analytical application

NASA Astrophysics Data System (ADS)

Amjadi, Mohammad; Manzoori, Jamshid L.; Hallaj, Tooba; Sorouraddin, Mohammad H.

2014-03-01

The chemiluminescence (CL) of water-soluble fluorescent carbon dots (C-dots) induced by direct chemical oxidation was investigated. C-dots were prepared by solvothermal method and characterized by fluorescence spectra and transmission electron microscopy. It was found that K3Fe(CN)6 could directly oxidize C-dots to produce a relatively intense CL emission. The mechanism of CL generation was investigated based on the fluorescence and CL emission spectra and the effect of radical scavengers on the CL intensity. The inhibitive effect of some metal ions and biologically important molecules on the CL intensity of the system was examined and the potential of the system for the determination of these species at trace levels was studied. In order to evaluate the capability of method to real sample analysis, it was applied to the determination of Cr(VI) and adrenaline in water and injection samples, respectively.

Groundwater withdrawal impacts in a karst area

NASA Astrophysics Data System (ADS)

Destephen, R. A.; Benson, C. P.

1993-12-01

During a 3000-gpm pump test on a groundwater supply well in Augusta County, Virginia, residential properties were impacted. The impacts included lowered farm pond water levels, development of a sinkhole, and water level decrease in residential wells. A study was performed to assess whether a lower design yield was possible with minimal impacts on adjacent property. This study included a 48-h 1500-gpm pump test that evaluated impacts due to: (1) sinkhole development and potential damage to homes, (2) loss of water in residential wells, and (3) water-quality degradation. Spring flows, residential well levels, survey monuments, and water quality were monitored. Groundwater and surface water testing included inorganic water-quality parameters and microbiological parameters. The latter included particulate analyses, Giardia cysts, and coliforms, which were used to evaluate the connection between groundwater and local surface waterbodies. Although results of the study indicated a low potential for structural damage due to future sinkhole activity, it showed that the water quality of some residential wells might be degraded. Because particulate analyses confirmed that groundwater into the supply well is under the direct influence of surface water, it was recommended that certain residents be placed on an alternate water supply prior to production pumping and that filtration be provided for the well in accordance with the Surface Water Treatment Rule. A mitigation plan was implemented. This plan included crack surveys, a long-term settlement station monitoring program, and limitation of the groundwater withdrawal rate to 1.0 million gallons per day (mgd) and maximum production rate to 1500 gpm.

Applicability of direct total reflection X-ray fluorescence analysis for selenium determination in solutions related to environmental and geochemical studies

NASA Astrophysics Data System (ADS)

Marguí, E.; Floor, G. H.; Hidalgo, M.; Kregsamer, P.; Roman-Ross, G.; Streli, C.; Queralt, I.

2010-12-01

A significant amount of environmental studies related to selenium determination in different environmental compartments have been published in the last years due to the narrow range between the Se nutritious requirement as essential element and toxic effects upon exposure. However, the direct analysis of complex liquid samples like natural waters and extraction solutions presents significant problems related to the low Se concentrations and the complicated matrix of this type of samples. The goal of the present research was to study the applicability of direct TXRF analysis of different type of solutions commonly used in environmental and geochemical studies, confirm the absence or presence of matrix effects and evaluate the limits of detection and accuracy for Se determination in the different matrices. Good analytical results were obtained for the direct analysis of ground and rain water samples with limits of detection for Se two orders of magnitude lower than the permissible Se concentration in drinking waters ([Se] = 10 μg/L) according to the WHO. However, the Se detection limits for more complex liquid samples such as thermal waters and extraction solutions were in the μg/L range due to the presence of high contents of other elements present in the matrix (i.e., Br, Fe, Zn) or the high background of the TXRF spectrum that hamper the Se determination at trace levels. Our results give insight into the possibilities and drawbacks of direct TXRF analysis and to a certain extent the potential applications in the environmental and geochemical field.

Louisiana Ground-Water Map No. 22: Generalized Potentiometric Surface of the Amite Aquifer and the "2,800-Foot" Sand of the Baton Rouge Area in Southeastern Louisiana, June-August 2006

USGS Publications Warehouse

Fendick, Robert B.

2007-01-01

The Amite aquifer and the '2,800-foot' sand of the Baton Rouge area (hereafter referred to as the '2,800-foot' sand) are principal sources of fresh ground water in southeastern Louisiana. Both the Amite aquifer and the '2,800-foot' sand are part of the Jasper equivalent aquifer system. The Amite aquifer is heavily pumped in the Bogalusa area, and the '2,800-foot' sand is one of the most heavily pumped aquifers in East Baton Rouge Parish. The Baton Rouge fault zone, which acts as a barrier to flow, trends approximately west-northwest from a point just south of The Rigolets through southern West Baton Rouge Parish, and is the approximate southern limit of freshwater in the aquifers. For the purposes of this report, freshwater is defined as water having less than 250 milligrams per liter (mg/L) of chloride, and most of the water withdrawals described in this report were assumed to be fresh. In 2005, about 18 million gallons per day (Mgal/d) was withdrawn from the Amite aquifer, primarily for public-supply use (8.4 Mgal/d) and industrial use (9.6 Mgal/d). During this same period, about 32 Mgal/d was withdrawn from the '2,800-foot' sand, primarily for public-supply use (13 Mgal/d) and industrial use (19 Mgal/d). Public-supply and industrial withdrawals from the Amite aquifer and the '2,800-foot' sand are listed in table 1. According to data from the Louisiana State Census Data Center, some of the largest population increases in the State during the period 1990 to 2000 occurred in St. Tammany (32.4 percent), Livingston (30.2 percent), and Tangipahoa (17.4 percent) Parishes. These population increases have been accompanied by increased withdrawals of ground water during the same period: 40 percent in St. Tammany Parish, 63 percent in Livingston Parish, and 35 percent in Tangipahoa Parish. An increase in population in these parishes is expected from population displacement due to damages from Hurricanes Katrina and Rita crossing the Louisiana coast in August and September of 2005. Additional information about ground-water flow and effects of increased withdrawals on water levels in the Amite aquifer and the '2,800-foot' sand is needed to assess ground-water-development potential and to protect this resource. To meet this need, the U.S. Geological Survey, in cooperation with the Louisiana Department of Transportation and Development, began a study in 2005 to determine water levels, flow direction, and water-level trends for the Amite aquifer and '2,800-foot' sand. This report presents data and a map that describe the generalized potentiometric surface of the Amite aquifer and '2,800-foot' sand in southeastern Louisiana. Graphs of water levels in selected wells and a table of withdrawals from the Amite aquifer and '2,800-foot' sand show historical changes in water levels and water use. The generalized potentiometric-surface map illustrates the water levels and ground-water flow directions for June-August 2006. These data are on file at the USGS office in Baton Rouge, Louisiana.

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.

Water security-National and global issues

USGS Publications Warehouse

Tindall, James A.; Campbell, Andrew A.

2010-01-01

Potable or clean freshwater availability is crucial to life and economic, environmental, and social systems. The amount of freshwater is finite and makes up approximately 2.5 percent of all water on the Earth. Freshwater supplies are small and randomly distributed, so water resources can become points of conflict. Freshwater availability depends upon precipitation patterns, changing climate, and whether the source of consumed water comes directly from desalination, precipitation, or surface and (or) groundwater. At local to national levels, difficulties in securing potable water sources increase with growing populations and economies. Available water improves living standards and drives urbanization, which increases average water consumption per capita. Commonly, disruptions in sustainable supplies and distribution of potable water and conflicts over water resources become major security issues for Government officials. Disruptions are often influenced by land use, human population, use patterns, technological advances, environmental impacts, management processes and decisions, transnational boundaries, and so forth.

Restoration of a mined peat bog in Delafield Township, Waukesha County, Wisconsin: Field and computer model studies of the hydrogeology and the growth of fen buckthorn (Rhamnus frangula)

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

Zolidis, N.R.

1988-01-01

In order to plan for the restoration of native wetland plant communities at a 105 ha mined peatbog in southeastern Wisconsin, studies of the hydrogeology and of the ecology of an invading exotic shrub species, fen buckthorn (Rhamnus frangula) were undertaken. A network of shallow wells, piezometers, and surface water gages were monitored monthly between September 1985 and September 1987 to delineate lateral and vertical directions of groundwater flow, fluctuations and depths of water table, and groundwater flow rates. Results indicate that groundwater recharge occurred in the active mining area and groundwater discharge occurred in most of the other areasmore » of the site. Summer depth to water table was more than 50cm in some areas suggesting that water levels should be raised to crease favorable sedge meadow habitat. In order to test the proposal of installing water control berms in the drainage ditches to raise water levels at the site, a groundwater flow model was constructed for low flow conditions which typically occur in late summer. The results of the steady state simulations indicated that water levels will be raised an average of approximately 12 cm. This values is at least 40 cm less than the proposed increases in the mined areas. Although the increase in water table elevation would enhance soil moisture conditions, other alternatives such as landscaping and natural modifications may also raise water levels and therefore need to be investigated. The rates of aboveground growth of fen buckthorn stems were estimated for the 1986 and 1987 growing season using regression equations based on measurements of biomass and stem diameter.« less

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

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.

Investigating water transport through the xylem network in vascular plants.

PubMed

Kim, Hae Koo; Park, Joonghyuk; Hwang, Ildoo

2014-04-01

Our understanding of physical and physiological mechanisms depends on the development of advanced technologies and tools to prove or re-evaluate established theories, and test new hypotheses. Water flow in land plants is a fascinating phenomenon, a vital component of the water cycle, and essential for life on Earth. The cohesion-tension theory (CTT), formulated more than a century ago and based on the physical properties of water, laid the foundation for our understanding of water transport in vascular plants. Numerous experimental tools have since been developed to evaluate various aspects of the CTT, such as the existence of negative hydrostatic pressure. This review focuses on the evolution of the experimental methods used to study water transport in plants, and summarizes the different ways to investigate the diversity of the xylem network structure and sap flow dynamics in various species. As water transport is documented at different scales, from the level of single conduits to entire plants, it is critical that new results be subjected to systematic cross-validation and that findings based on different organs be integrated at the whole-plant level. We also discuss the functional trade-offs between optimizing hydraulic efficiency and maintaining the safety of the entire transport system. Furthermore, we evaluate future directions in sap flow research and highlight the importance of integrating the combined effects of various levels of hydraulic regulation.

Potentiometric Surface of the Upper and Lower Aquifers of the North Coast Limestone Aquifer System and Hydrologic Conditions in the Arecibo-Manati Area, Puerto Rico, November 27-December 1, 2006

USGS Publications Warehouse

Rodriguez, Jose M.; Gómez-Gómez, Fernando

2008-01-01

A ground-water level synoptic survey of the limestone aquifer in the Arecibo to Manati area, Puerto Rico, was conducted from November 27 through December 1, 2006 by the U.S. Geological Survey in cooperation with the Puerto Rico Department of Natural and Environmental Resources. The purpose of the study was to define the spatial distribution of the potentiometric surface of the upper and lower aquifers of the North Coast limestone aquifer system. A potentiometric surface is defined as an areal representation of the levels to which water would rise in tightly cased wells open to an aquifer (Fetter, 1988). These potentiometric surface maps can be used by water-resources planners to understand the general direction of ground-water flow and to evaluate ground-water conditions for water supply and resource protection. The study was conducted during a period of rising ground-water levels resulting from above-normal rainfall during October and November 2006 when rainfall amount was about 30 percent above normal. The study area encompassed 125 square miles and was bounded to the north by the Atlantic Ocean, to the south by the southern extension of the limestone units, to the west by the Rio Grande de Arecibo, and to the east by the Rio Grande de Manati (pls. 1 and 2; inset).

Water quality and antifungal susceptibility of opportunistic yeast pathogens from rivers.

PubMed

Monapathi, M E; Bezuidenhout, C C; Rhode, O H J

2017-03-01

Yeasts from water sources have been associated with diseases ranging from superficial mucosal infections to life threatening diseases. The aim of this study was to determine the water quality as well as diversity and antifungal susceptibility of yeasts from two rivers. Yeast levels and physico-chemical parameter data were analyzed by principal component analysis to determine correlations between physico-chemical data and yeast levels. Yeast morphotypes were identified by biochemical tests and 26S rRNA gene sequencing. Disk diffusion antifungal susceptibility tests were conducted. Physico-chemical parameters of the water were within target water quality range (TWQR) for livestock farming. For irrigational use, total dissolved solids and nitrates were not within the TWQR. Yeast levels ranged between 27 ± 10 and 2,573 ± 306 cfu/L. Only non-pigmented, ascomycetous yeasts were isolated. Saccharomyces cerevisiae and Candida glabrata were most frequently isolated. Several other opportunistic pathogens were also isolated. A large number of isolates were resistant to azoles, especially fluconazole, but also to other antifungal classes. Candida species were resistant to almost all the antifungal classes. These water sources are used for recreation and religious as well as for watering livestock and irrigation. Of particular concern is the direct contact of individuals with opportunistic yeast, especially the immune-compromised. Resistance of these yeast species to antifungal agents is a further health concern.

Chlorine dioxide water disinfection: a prospective epidemiology study

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

Michael, G.E.; Miday, R.K.; Bercz, J.P.

An epidemiologic study of 198 persons exposed for 3 months to drinking water disinfected with chlorine dioxide was conducted in a rural village. A control population of 118 nonexposed persons was also studied. Pre-exposure hematologic and serum chemical parameters were compared with test results after 115 days of exposure. Chlorite ion levels in the water averaged approximately 5 ppM during the study period. Statistical analysis (ANOVA) of the data failed to identify any significant exposure-related effects. This study suggests that future evaluations of chlorine dioxide disinfection should be directed toward populations with potentially increased sensitivity to hemolytic agents.

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.

Subnanopore filling during water vapor adsorption on microporous silica thin films as seen by low-energy positron annihilation

NASA Astrophysics Data System (ADS)

Ito, Kenji; Yoshimoto, Shigeru; O'Rourke, Brian E.; Oshima, Nagayasu; Kumagai, Kazuhiro

2018-02-01

Positron annihilation lifetime spectroscopy (PALS) using a low-energy positron microbeam extracted into air was applied to elucidating molecular-level pore structures formed in silicon-oxide-backboned microporous thin films under controlled humidity conditions; as a result, a direct observation of the interstitial spaces in the micropores filled with water molecules was achieved. It was demonstrated that PALS using a microbeam extracted into air in combination with water vapor adsorption is a powerful tool for the in-situ elucidation of both open and closed subnanoscaled pores of functional thin materials under practical conditions.

[The effect of mineral water on serotonin and insulin production (an experimental study)].

PubMed

Polushina, N D

1998-01-01

Radioimmunoassay (DRG kits) and orthotoluidine test were conducted to measure blood serotonin, insulin and glucose in 70 intact Wistar rat males before and after a course of drinking mineral water Essentuki 17 (MW). After the MW drinking course, a single dose of mineral water increases basal levels of serotonin and insulin, sensitivity of endocrine cells to MW. Serotonin and insulin rose maximally on minute 5 after the drink while in contrast to minute 15 and 30 before initiation of the MW drinking course. A direct correlation was found between blood concentrations of serotonin and insulin.

Bacterial communities in an ultrapure water containing storage tank of a power plant.

PubMed

Bohus, Veronika; Kéki, Zsuzsa; Márialigeti, Károly; Baranyi, Krisztián; Patek, Gábor; Schunk, János; Tóth, Erika M

2011-12-01

Ultrapure waters (UPWs) containing low levels of organic and inorganic compounds provide extreme environment. On contrary to that microbes occur in such waters and form biofilms on surfaces, thus may induce corrosion processes in many industrial applications. In our study, refined saltless water (UPW) produced for the boiler of a Hungarian power plant was examined before and after storage (sampling the inlet [TKE] and outlet [TKU] waters of a storage tank) with cultivation and culture independent methods. Our results showed increased CFU and direct cell counts after the storage. Cultivation results showed the dominance of aerobic, chemoorganotrophic α-Proteobacteria in both samples. In case of TKU sample, a more complex bacterial community structure could be detected. The applied molecular method (T-RFLP) indicated the presence of a complex microbial community structure with changes in the taxon composition: while in the inlet water sample (TKE) α-Proteobacteria (Sphingomonas sp., Novosphingobium hassiacum) dominated, in the outlet water sample (TKU) the bacterial community shifted towards the dominance of α-Proteobacteria (Rhodoferax sp., Polynucleobacter sp., Sterolibacter sp.), CFB (Bacteroidetes, formerly Cytophaga-Flavobacterium-Bacteroides group) and Firmicutes. This shift to the direction of fermentative communities suggests that storage could help the development of communities with an increased tendency toward corrosion.

Hydrology and simulation of ground-water flow in Juab Valley, Juab County, Utah.

USGS Publications Warehouse

Thiros, Susan A.; Stolp, Bernard J.; Hadley, Heidi K.; Steiger, Judy I.

1996-01-01

Plans to import water to Juab Valley, Utah, primarily for irrigation, are part of the Central Utah Project. A better understanding of the hydrology of the valley is needed to help manage the water resources and to develop conjunctive-use plans.The saturated unconsolidated basin-fill deposits form the ground-water system in Juab Valley. Recharge is by seepage from streams, unconsumed irrigation water, and distribution systems; infiltration of precipitation; and subsurface inflow from consolidated rocks that surround the valley. Discharge is by wells, springs, seeps, evapotranspiration, and subsurface outflow to consolidated rocks. Ground-water pumpage is used to supplement surface water for irrigation in most of the valley and has altered the direction of groundwater flow from that of pre-ground-water development time in areas near and in Nephi and Levan.Greater-than-average precipitation during 1980-87 corresponds with a rise in water levels measured in most wells in the valley and the highest water level measured in some wells. Less-than average precipitation during 1988-91 corresponds with a decline in water levels measured during 1988-93 in most wells. Geochemical analyses indicate that the sources of dissolved ions in water sampled from the southern part of the valley are the Arapien Shale, evaporite deposits that occur in the unconsolidated basin-fill deposits, and possibly residual sea water that has undergone evaporation in unconsolidated basin-fill deposits in selected areas. Water discharging from a spring at Burriston Ponds is a mixture of about 70 percent ground water from a hypothesized flow path that extends downgradient from where Salt Creek enters Juab Valley and 30 percent from a hypothesized flow path from the base of the southern Wasatch Range.The ground-water system of Juab Valley was simulated by using the U.S. Geological Survey modular, three-dimensional, finite-difference, ground-water flow model. The numerical model was calibrated to simulate the steady-state conditions of 1949, multi-year transient-state conditions during 1949-92, and seasonal transient-state conditions during 1992-94. Calibration parameters were adjusted until model-computed water levels reasonably matched measured water levels. Parameters important to the calibration process include horizontal hydraulic conductivity, transmissivity, and the spatial distribution and amount of recharge from subsurface inflow and seepage from ephemeral streams to the east side of Juab Valley.

Water bicarbonate modulates the response of the shore crab Carcinus maenas to ocean acidification.

PubMed

Maus, Bastian; Bock, Christian; Pörtner, Hans-O

2018-05-23

Ocean acidification causes an accumulation of CO 2 in marine organisms and leads to shifts in acid-base parameters. Acid-base regulation in gill breathers involves a net increase of internal bicarbonate levels through transmembrane ion exchange with the surrounding water. Successful maintenance of body fluid pH depends on the functional capacity of ion-exchange mechanisms and associated energy budget. For a detailed understanding of the dependence of acid-base regulation on water parameters, we investigated the physiological responses of the shore crab Carcinus maenas to 4 weeks of ocean acidification [OA, P(CO 2 ) w  = 1800 µatm], at variable water bicarbonate levels, paralleled by changes in water pH. Cardiovascular performance was determined together with extra-(pH e ) and intracellular pH (pH i ), oxygen consumption, haemolymph CO 2 parameters, and ion composition. High water P(CO 2 ) caused haemolymph P(CO 2 ) to rise, but pH e and pH i remained constant due to increased haemolymph and cellular [HCO 3 - ]. This process was effective even under reduced seawater pH and bicarbonate concentrations. While extracellular cation concentrations increased throughout, anion levels remained constant or decreased. Despite similar levels of haemolymph pH and ion concentrations under OA, metabolic rates, and haemolymph flow were significantly depressed by 40 and 30%, respectively, when OA was combined with reduced seawater [HCO 3 - ] and pH. Our findings suggest an influence of water bicarbonate levels on metabolic rates as well as on correlations between blood flow and pH e . This previously unknown phenomenon should direct attention to pathways of acid-base regulation and their potential feedback on whole-animal energy demand, in relation with changing seawater carbonate parameters.

Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water.

PubMed

Cragin, Lori A; Kesner, James S; Bachand, Annette M; Barr, Dana Boyd; Meadows, Juliana W; Krieg, Edward F; Reif, John S

2011-11-01

Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels. Women 18-40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption. Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58-13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29-29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58-20.77). Estimated "dose" of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine "dose" from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels. We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles. Copyright © 2011 Elsevier Inc. All rights reserved.

Glaciers and small ice caps in the macro-scale hydrological cycle - an assessment of present conditions and future changes

NASA Astrophysics Data System (ADS)

Lammers, Richard; Hock, Regine; Prusevich, Alexander; Bliss, Andrew; Radic, Valentina; Glidden, Stanley; Grogan, Danielle; Frolking, Steve

2014-05-01

Glacier and small ice cap melt water contributions to the global hydrologic cycle are an important component of human water supply and for sea level rise. This melt water is used in many arid and semi-arid parts of the world for direct human consumption as well as indirect consumption by irrigation for crops, serving as frozen reservoirs of water that supplement runoff during warm and dry periods of summer when it is needed the most. Additionally, this melt water reaching the oceans represents a direct input to sea level rise and therefore accurate estimates of this contribution have profound economic and geopolitical implications. It has been demonstrated that, on the scale of glacierized river catchments, land surface hydrological models can successfully simulate glacier contribution to streamflow. However, at global scales, the implementation of glacier melt in hydrological models has been rudimentary or non-existent. In this study, a global glacier mass balance model is coupled with the University of New Hampshire Water Balance/Transport Model (WBM) to assess recent and projected future glacier contributions to the hydrological cycle over the global land surface (excluding the ice sheets of Greenland and Antarctica). For instance, results of WBM simulations indicate that seasonal glacier melt water in many arid climate watersheds comprises 40 % or more of their discharge. Implicitly coupled glacier and WBM models compute monthly glacier mass changes and resulting runoff at the glacier terminus for each individual glacier from the globally complete Randolph Glacier Inventory including over 200 000 glaciers. The time series of glacier runoff is aggregated over each hydrological modeling unit and delivered to the hydrological model for routing downstream and mixing with non-glacial contribution of runoff to each drainage basin outlet. WBM tracks and uses glacial and non-glacial components of the in-stream water for filling reservoirs, transfers of water between drainage basins (inter-basin hydrological transfers), and irrigation along the global system of rivers with net discharge to the ocean. Climate scenarios from global climate models prepared for IPCC AR5 are used to explore an expected range of possible future glacier outflow variability to estimate the impacts on human use of these valuable waters and their poorly understood net contribution to sea level change.

A New Approach for Assessing Aquifer Sustainability and the Impact of Proposed Management Actions

NASA Astrophysics Data System (ADS)

Butler, J. J., Jr.; Whittemore, D. O.; Wilson, B. B.

2015-12-01

Aquifers are under stress worldwide as a result of large imbalances between inflows and outflows. These imbalances are particularly severe in aquifers in semi-arid regions that are heavily pumped for irrigation, such as the High Plains aquifer (HPA) in the United States. The water resources community has responded by placing an increasing emphasis on more sustainable management plans. To aid in the formulation of such plans, we have developed a simple, water-balance-based approach for rapid assessment of the impact of proposed management actions and the prospects for aquifer sustainability. This theoretically sound approach is particularly well suited for assessing the short- to medium-term (years to a few decades) response to management actions in seasonably pumped aquifers. The net inflow (capture) term of the aquifer water balance can also be directly calculated from water-level and water-use data with this approach. Application to the data-rich portion of the HPA in the state of Kansas reveals that practically achievable reductions in annual pumping would have a large impact. For example, a 22% reduction in average annual water use would have stabilized areally averaged water levels across northwest Kansas from 1996 to 2013 because of larger-than-expected and near-constant net inflows. Whether this is a short-term phenomenon or a path to long-term sustainability, however, has yet to be determined. Water resources managers are often in a quandary about the most effective use of scarce funds for data collection in support of aquifer assessment and management activities. This work demonstrates that a strong emphasis should be placed on collection of reliable water-use data; greater resources devoted to direct measurement of pumping will yield deeper insights into an aquifer's future. The Kansas HPA is similar to many other regional aquifers supporting critically needed agricultural production, so this approach should prove of value far beyond the borders of Kansas.

Geohydrologic reconnaissance of drainage wells in Florida

USGS Publications Warehouse

Kimrey, J.O.; Fayard, L.D.

1984-01-01

Drainage wells are used to inject surface waters directly into an aquifer, or shallow ground waters directly into a deeper aquifer, primarily by gravity. Such wells in Florida may be grouped into two broad types: (1) surface-water injection wells, and (2) interaquifer connector wells. Drainage wells of the first type are further categorized as either Floridan aquifer drainage wells or Biscayne aquifer drainage wells. Floridan aquifer drainage wells are commonly used to supplement drainage for urban areas in karst terranes of central and north Florida. Data are available for 25 wells in the Ocala, Live Oak, and Orlando areas that allow comparison of the quality of water samples from these Floridan aquifer drainage wells with allowable contaminant levels. Comparison indicates that maximum contaminant levels for turbidity, color, and iron, manganese, and lead concentrations are equaled or exceeded in some drainage-well samples, and relatively high counts for coliform bacteria are present in most wells. Biscayne aquifer drainage wells are used locally to dispose of stormwater runoff and other surplus water in southeast Florida, where large numbers of these wells have been permitted in Dade and Broward Counties. The majority of these wells are used to dispose of water from swimming pools or to dispose of heated water from air-conditioning units. The use of Biscayne aquifer drainage wells may have minimal effect on aquifer potability so long as injection of runoff and industrial wates is restricted to zones where chloride concentrations exceed 1,500 milligrams per liter. Interaquifer connector wells are used in the phosphate mining areas of Polk and Hillsborough Counties, to drain mines and recharge the Floridan aquifer. Water-quality data available from 13 connector wells indicate that samples from most of these wells exceed standards values for iron concentration and turbidity. One well yielded a highly mineralized water, and samples from 6 of the other 12 wells exceed standards values for gross alpha concentrations. (USGS)

The National Danish Water Resources Model - using an integrated groundwater - surface water model for decision support and WFD implementation in a changing climate

NASA Astrophysics Data System (ADS)

Lajer Hojberg, Anker; Hinsby, Klaus; Jørgen Henriksen, Hans; Troldborg, Lars

2014-05-01

Integrated and sustainable water resources management and development of river basin management plans according to the Water Framework Directive is getting increasingly complex especially when taking projected climate change into account. Furthermore, uncertainty in future developments and incomplete knowledge of the physical system introduces a high degree of uncertainty in the decision making process. Knowledge based decision making is therefore vital for formulation of robust management plans and to allow assessment of the inherent uncertainties. The Department of Hydrology at the Geological Survey of Denmark and Greenland started in 1996 to develop a mechanistically, transient and spatially distributed groundwater-surface water model - the DK-model - for the assessment of groundwater quantitative status accounting for interactions with surface water and anthropogenic changes, such as extraction strategies and land use, as well as climate change. The model has been subject to continuous update building on hydrogeological knowledge established by the regional water authorities and other national research institutes. With the on-going improvement of the DK-model it is now increasingly applied both by research projects and for decision support e.g. in implementation of the Water Framework Directive or to support other decisions related to protection of water resources (quantitative and chemical status), ecosystems and the built environment. At present, the DK-model constitutes the backbone of a strategic modelling project funded by the Danish Environmental Protection Agency, with the aim of developing a modelling complex that will provide the foundation of the implementation of the Water Framework Directive. Since 2003 the DK-model has been used in more than 25 scientific papers and even more public reports. In the poster and the related review paper we describe the most important applications in both science and policy, where the DK-model has been used either directly or as an important starting point for assessing the impact of climate change on the quantity and quality of groundwater and surface water e.g. in relation to changes in water tables, runoff, nutrient loadings, flooding risks (coastal and hinterland), irrigation demands, sea level rise and seawater intrusion or to assess where geology or climate change create the largest uncertainty for evaluation of the development of water resources quantity and quality.

Water Quality and Hydrology of Silver Lake, Barron County, Wisconsin, With Special Emphasis on Responses of a Terminal Lake to Changes in Phosphorus Loading and Water Level

USGS Publications Warehouse

Robertson, Dale M.; Rose, William J.; Fitzpatrick, Faith A.

2009-01-01

Silver Lake is typically an oligotrophic-to-mesotrophic, soft-water, terminal lake in northwestern Wisconsin. A terminal lake is a closed-basin lake with surface-water inflows but no surface-water outflows to other water bodies. After several years with above-normal precipitation, very high water levels caused flooding of several buildings near the lake and erosion of soil around much of the shoreline, which has been associated with a degradation in water quality (increased phosphorus and chlorophyll a concentrations and decreased water clarity). To gain a better understanding of what caused the very high water levels and degradation in water quality and collect 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. This report describes results of the study; specifically, lake-water quality, historical changes in water level, water and phosphorus budgets for the two years monitored in the study, results of model simulations that demonstrate how changes in phosphorus inputs affect lake-water quality, and the relative importance of changes in hydrology and changes in the watershed to the water quality of the lake. From 1987 to about 1996, water quality in Silver Lake was relatively stable. Since 1996, however, summer average total phosphorus concentrations increased from about 0.008 milligrams per liter (mg/L) to 0.018 mg/L in 2003, before decreasing to 0.011 mg/L in 2008. From 1996 to 2003, Secchi depths decreased from about 14 to 7.4 feet, before increasing to about 19 feet in 2008. Therefore, Silver Lake is typically classified as oligotrophic to mesotrophic; however, during 2002-4, the lake was classified as mesotrophic to eutrophic. Because productivity in Silver Lake is limited by phosphorus, phosphorus budgets for the lake were constructed for monitoring years 2005 and 2006. The average annual input of phosphorus was 216 pounds: 78 percent from tributary and nearshore runoff and 22 percent from atmospheric deposition. Because Silver Lake is hydraulically mounded above the local groundwater system, little or no input of phosphorus to the lake is from groundwater and septic systems. Silver Lake had previously been incorrectly described as a groundwater flowthrough lake. Phosphorus budgets were constructed for a series of dry years (low water levels) and a series of wet years (high water levels). About 6 times more phosphorus was input to the lake during wet years with high water levels than during the dry years. Phosphorus from erosion represented 13-20 percent of the phosphorus input during years with very high water levels. Results from the Canfield and Bachman eutrophication model and Carlson trophic state index equations demonstrated that water quality in Silver Lake directly responds to changes in external phosphorus input, with the percent change in chlorophyll a being about 80 percent of the percent change in total phosphorus input and the change in Secchi depth and total phosphorus concentrations being about 40 and 50 percent of the percent change in input, respectively. Therefore, changes in phosphorus input should impact water quality. Specific scenarios were simulated with the models to describe the effects of natural (climate-driven) and anthropogenic (human-induced) changes. Results of these scenarios demonstrated that several years of above-normal precipitation cause sustained high water levels and a degradation in water quality, part of which is due to erosion of the shoreline. Results also demonstrated that 1) changes in tributary and nearshore runoff have a dramatic effect on lake-water quality, 2) diverting water into the lake to increase the water level is expected to degrade the water quality, and 3) removal of water to decrease the water level of the lake is expected to have little effect on water quality. Fluctuations in water levels since 1967, when records began for the lake, are representative

Cesium, iodine and tritium in NW Pacific waters - a comparison of the Fukushima impact with global fallout

NASA Astrophysics Data System (ADS)

Povinec, P. P.; Aoyama, M.; Biddulph, D.; Breier, R.; Buesseler, K.; Chang, C. C.; Golser, R.; Hou, X. L.; Ješkovský, M.; Jull, A. J. T.; Kaizer, J.; Nakano, M.; Nies, H.; Palcsu, L.; Papp, L.; Pham, M. K.; Steier, P.; Zhang, L. Y.

2013-08-01

Radionuclide impact of the Fukushima Dai-ichi nuclear power plant accident on the distribution of radionuclides in seawater of the NW Pacific Ocean is compared with global fallout from atmospheric tests of nuclear weapons. Surface and water column samples collected during the Ka'imikai-o-Kanaloa (KOK) international expedition carried out in June 2011 were analyzed for 134Cs, 137Cs, 129I and 3H. The 137Cs, 129I and 3H levels in surface seawater offshore Fukushima varied between 0.002-3.5 Bq L-1, 0.01-0.8 μBq L-1, and 0.05-0.15 Bq L-1, respectively. At the sampling site about 40 km from the coast, where all three radionuclides were analyzed, the Fukushima impact on the levels of these three radionuclides represents an increase above the global fallout background by factors of about 1000, 50 and 3, respectively. The water column data indicate that the transport of Fukushima-derived radionuclides downward to the depth of 300 m has already occurred. The observed 137Cs levels in surface waters and in the water column are compared with predictions obtained from the ocean general circulation model, which indicates that the Kuroshio Current acts as a southern boundary for the transport of the radionuclides, which have been transported from the Fukushima coast eastward in the NW Pacific Ocean. The 137Cs inventory in the water column is estimated to be about 2.2 PBq, what can be regarded as a lower limit of the direct liquid discharges into the sea as the seawater sampling was carried out only in the area from 34 to 37° N, and from 142 to 147° E. About 4.6 GBq of 129I was deposited in the NW Pacific Ocean, and 2.4-7 GBq of 129I was directly discharged as liquid wastes into the sea offshore Fukushima. The total amount of 3H released and deposited over the NW Pacific Ocean was estimated to be 0.1-0.5 PBq. These estimations depend, however, on the evaluation of the total 137Cs activities released as liquid wastes directly into the sea, which should improve when more data are available. Due to a suitable residence time in the ocean, Fukushima-derived radionuclides will provide useful tracers for isotope oceanography studies on the transport of water masses during the next decades in the NW Pacific Ocean.

Analysis of fecal coliform levels at selected storm water monitoring points at the Oak Ridge Y-12 Plant

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

Skaggs, B.E.

1995-07-01

The Environmental Protection Agency staff published the final storm water regulation on November 16, 1990. The storm water regulation is included in the National Pollutant Discharge Elimination System (NPDES) regulations. It specifies the permit application requirements for certain storm water discharges such as industrial activity or municipal separate storm sewers serving populations of 100,000 or greater. Storm water discharge associated with industrial activity is discharge from any conveyance used for collecting and conveying storm water that is directly related to manufacturing, processing, or raw material storage areas at an industrial plant. Quantitative testing data is required for these discharges. Anmore » individual storm water permit application was completed and submitted to Tennessee Department of Environment and Conservation (TDEC) personnel in October 1992. After reviewing this data in the permit application, TDEC personnel expressed concern with the fecal coliform levels at many of the outfalls. The 1995 NPDES Permit (Part 111-N, page 44) requires that an investigation be conducted to determine the validity of this data. If the fecal coliform data is valid, the permit requires that a report be submitted indicating possible causes and proposed corrective actions.« less

Application of Trophic Magnification Factors (TMFs) Under the ...

EPA Pesticide Factsheets

Directive 2013/39/EU amending and updating the Water Framework Directive (2000/60/EC) and its Daughter Directive (the so-called EQS Directive: 2008/105/EC) sets Environmental Quality Standards for biota (EQSbiota) for a number of bioaccumulative chemicals which can pose a threat to both aquatic wildlife (piscivorous birds and mammals) and human health via the consumption of contaminated prey or the intake of contaminated food originating from the aquatic environment. Member States (MS) of the European Union will need to establish programs to monitor the concentration of 11 priority substances in biota and assess compliance against these new standards for surface water classification. The biota standards essentially refer to fish and should be applied to the trophic level (TL) at which contaminant concentrations peak, so that the predator of the species at that TL is exposed to the highest contaminant levels in its food. For chemicals that are subject to biomagnification, the peak concentrations are theoretically attained at TL 3 to 4 in freshwater food webs and TL 5 in marine food webs, where the risk of secondary poisoning of top predators should also be considered. An EU-wide guidance effectively addresses the implementation of EQSbiota (EC 2014). Flexibility is allowed in the choice of target species used for monitoring because of the diversity of both habitats and aquatic community composition across Europe. According to that guidance, the consistency and co

An Environmental Health Assessment: Fecal Coliform Contamination in San Francisco Waterbodies

NASA Astrophysics Data System (ADS)

Devillier, K. N.; Devine, M.; Negrete, R.; Rawley, A. L.; Neiss, J.

2007-12-01

Fecal coliform is a group of bacteria that exists in the digestive system and excrement of warm-blooded animals. It enters aquatic environments through fecal contamination of water. In the urban environment, contamination can occur not only by direct input from warm-blooded animals but also from storm water run-off and municipal sewer overflow. Fecal coliform itself does not cause disease but it is an indicator of the presence of pathogens that exist in the wastes of humans and animals that are a hazard to human health. We examined 12 locations in San Francisco for fecal coliform and recorded the types of human contact with water at each location. We found low levels of coliform in areas open to the San Francisco Bay and Pacific Ocean and high levels of coliform in inland lakes and ponds. Using Environmental Protection Agency guidelines for fecal coliform concentrations, we found all sites at acceptable levels for the recreational and human activities we observed.

Ambient noise dynamics in a heavy shipping area.

PubMed

Kinda, G Bazile; Le Courtois, Florent; Stéphan, Yann

2017-11-15

The management of underwater noise within the European Union's waters is a significant component (Descriptor 11) of the Marine Strategy Framework Directive (MSFD). The indicator related to continuous noise, is the noise levels in two one-third octave bands centered at 63Hz and 125Hz. This paper presents an analysis of underwater noise in the Celtic Sea, a heavy shipping area which also hosts the seasonal Ushant thermal front. In addition to the MSFD recommended frequency bands, the analysis was extended to lower and upper frequency bands. Temporal and spatial variations as well as the influence of the properties of the water column on the noise levels were assessed. The noise levels in the area had a high dynamic range and generally exceeded 100dB re 1μPa. Finally, the results highlighted that oceanic mooring must be designed to minimize the pseudo-noise and consider the water column physical properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Leachate water quality of soils amended with different swine manure-based amendments

USDA-ARS?s Scientific Manuscript database

In the face of the rising level of manure production from concentrated animal feeding operations (CAFOs), management options are being sought that can provide nutrient recycling for plant growth and improved soil conditions with minimal environmental impacts. Alternatives to direct manure applicatio...

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)

Transfer rates of enteric microorganisms in recycled water during machine clothes washing.

PubMed

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

2009-03-01

Approximately 15% of overall Australian household water usage is in the laundry; hence, a significant reduction in household drinking water demand could be achieved if potable-quality water used for clothes washing is replaced with recycled water. To investigate the microbiological safety of using recycled water in washing machines, bacteriophages MS-2 and PRD-1, Escherichia coli, and Cryptosporidium parvum oocysts were used in a series of experiments to investigate the transfer efficiency of enteric microorganisms from washing machine water to objects including hands, environmental surfaces, air, and fabric swatches. By determining the transference efficiency, it is possible to estimate the numbers of microorganisms that the user will be exposed to if recycled water with various levels of residual microorganisms is used in washing machines. Results, expressed as transfer rates to a given surface area per object, showed that the mean transfer efficiency of E. coli, bacteriophages MS-2 and PRD-1, and C. parvum oocysts from seeded water to fabric swatches ranged from 0.001% to 0.090%. Greatest exposure to microorganisms occurred through direct contact of hands with seeded water and via hand contact with contaminated fabric swatches. No microorganisms were detected in the air samples during the washing machine spin cycle, and transfer rates of bacteriophages from water to environmental surfaces were 100-fold less than from water directly to hands. Findings from this study provide relevant information that can be used to refine regulations governing recycled water and to allay public concerns about the use of recycled water.

Characterizing Hydrological Processes in Vadose Zone by Direct Infiltration Water Sampling.

NASA Astrophysics Data System (ADS)

Mori, Y.; Higashi, N.; Somura, H.; Takeda, I.; Inoue, M.

2007-12-01

These days, planted forest mountainside was roughly maintained due to the population descent and small birth rate. Because thinning operation would delayed, forest was always dark and floor weed was rare. Management induced non point source pollution like surface soil erosion was suspected, however, we could not approach to the source with the stream water analysis. Therefore, direct soil water sampling device using glass fiber capillary force was developed to examine hydrological processes in watershed. In our design, water was collected just by the capillary force and let the excess water down through so that infiltration water was truly sampled and solute concentration kept the same quality as in soil water. The experiment was conducted at two neighboring Japanese cedar planted forest under different management, i.e., south slope was roughly maintained and west slope was well maintained by thinning operation. Load discharges were higher in south slope and lower in west slope. Infiltration water analysis revealed that ion concentration was gradually decreased at west slope, however in south slope, it dropped to lower level in soil water and increased again in stream water. The trend showed that soil buffering function was poor in south slope. Actually, disk permeameter survey revealed that hydraulic conductivity was small in south slope; TOC and biological activity were lower. This entire soil environment explained the water environmental differences in stream water. Because changes in soil environment affects water environment in the future, monitoring or examination of soil environment was considered as preventive measure for environmentally sound water and solute circulation in watershed.

Relative significance of microtopography and vegetation as controls on surface water flow on a low-gradient floodplain

USGS Publications Warehouse

Choi, Jungyill; Harvey, Judson W.

2014-01-01

Surface water flow controls water velocities, water depths, and residence times, and influences sediment and nutrient transport and other ecological processes in shallow aquatic systems. Flow through wetlands is substantially influenced by drag on vegetation stems but is also affected by microtopography. Our goal was to use microtopography data directly in a widely used wetland model while retaining the advantages of the model’s one-dimensional structure. The base simulation with no explicit treatment of microtopography only performed well for a period of high water when vegetation dominated flow resistance. Extended simulations using microtopography can improve the fit to low-water conditions substantially. The best fit simulation had a flow conductance parameter that decreased in value by 70 % during dry season such that mcrotopographic features blocked 40 % of the cross sectional width for flow. Modeled surface water became ponded and flow ceased when 85 % of the cross sectional width became blocked by microtopographic features. We conclude that vegetation drag dominates wetland flow resistance at higher water levels and microtopography dominates at low water levels with the threshold delineated by the top of microtopographic features. Our results support the practicality of predicting flow on floodplains using relatively easily measured physical and biological variables.

Ground-Water Resources in Kaloko-Honokohau National Historical Park, Island of Hawaii, and Numerical Simulation of the Effects of Ground-Water Withdrawals

USGS Publications Warehouse

Oki, Delwyn S.; Tribble, Gordon W.; Souza, William R.; Bolke, Edward L.

1999-01-01

Within the Kaloko-Honokohau National Historical Park, which was established in 1978, the ground-water flow system is composed of brackish water overlying saltwater. Ground-water levels measured in the Park range from about 1 to 2 feet above mean sea level, and fluctuate daily by about 0.5 to 1.5 feet in response to ocean tides. The brackish water is formed by mixing of seaward flowing fresh ground water with underlying saltwater from the ocean. The major source of fresh ground water is from subsurface flow originating from inland areas to the east of the Park. Ground-water recharge from the direct infiltration of precipitation within the Park area, which has land-surface altitudes less than 100 feet, is small because of low rainfall and high rates of evaporation. Brackish water flowing through the Park ultimately discharges to the fishponds in the Park or to the ocean. The ground water, fishponds, and anchialine ponds in the Park are hydrologically connected; thus, the water levels in the ponds mark the local position of the water table. Within the Park, ground water near the water table is brackish; measured chloride concentrations of water samples from three exploratory wells in the Park range from 2,610 to 5,910 milligrams per liter. Chromium and copper were detected in water samples from the three wells in the Park and one well upgradient of the Park at concentrations of 1 to 5 micrograms per liter. One semi-volatile organic compound, phenol, was detected in water samples from the three wells in the Park at concentrations between 4 and 10 micrograms per liter. A regional, two-dimensional (areal), freshwater-saltwater, sharp-interface ground-water flow model was used to simulate the effects of regional withdrawals on ground-water flow within the Park. For average 1978 withdrawal rates, the estimated rate of fresh ground-water discharge to the ocean within the Park is about 6.48 million gallons per day, or about 3 million gallons per day per mile of coastline. Although the coastal discharge within the Park is actually brackish water, the model assumes that freshwater and saltwater do not mix and therefore the model-calculated coastal discharge within the Park is in the form of freshwater discharge. Model results indicate that ground-water withdrawals in excess of average 1978 withdrawal rates will reduce the rate of freshwater coastal discharge within the Park. Withdrawals from wells directly upgradient of the Park had the greatest effect on the model-calculated freshwater coastal discharge within the Park, whereas withdrawals from wells south of Papa Bay had little effect on the freshwater discharge within the Park. For an increased ground-water withdrawal rate of 56.8 million gallons per day, relative to average 1978 withdrawal rates in the Kona area, model-calculated freshwater coastal discharge within the Park was reduced by about 47 percent.

How can climate change and engineered water conveyance affect sediment dynamics in the San Francisco Bay-Delta system?

USGS Publications Warehouse

Achete, Fernanda; Van der Wegen, Mick; Roelvink, Jan Adriaan; Jaffe, Bruce E.

2017-01-01

Suspended sediment concentration is an important estuarine health indicator. Estuarine ecosystems rely on the maintenance of habitat conditions, which are changing due to direct human impact and climate change. This study aims to evaluate the impact of climate change relative to engineering measures on estuarine fine sediment dynamics and sediment budgets. We use the highly engineered San Francisco Bay-Delta system as a case study. We apply a process-based modeling approach (Delft3D-FM) to assess the changes in hydrodynamics and sediment dynamics resulting from climate change and engineering scenarios. The scenarios consider a direct human impact (shift in water pumping location), climate change (sea level rise and suspended sediment concentration decrease), and abrupt disasters (island flooding, possibly as the results of an earthquake). Levee failure has the largest impact on the hydrodynamics of the system. Reduction in sediment input from the watershed has the greatest impact on turbidity levels, which are key to primary production and define habitat conditions for endemic species. Sea level rise leads to more sediment suspension and a net sediment export if little room for accommodation is left in the system due to continuous engineering works. Mitigation measures like levee reinforcement are effective for addressing direct human impacts, but less effective for a persistent, widespread, and increasing threat like sea level rise. Progressive adaptive mitigation measures to the changes in sediment and flow dynamics resulting from sea level rise may be a more effective strategy. Our approach shows that a validated process-based model is a useful tool to address long-term (decades to centuries) changes in sediment dynamics in highly engineered estuarine systems. In addition, our modeling approach provides a useful basis for long-term, process-based studies addressing ecosystem dynamics and health.

Lake level fluctuations boost toxic cyanobacterial "oligotrophic blooms".

PubMed

Callieri, Cristiana; Bertoni, Roberto; Contesini, Mario; Bertoni, Filippo

2014-01-01

Global warming has been shown to strongly influence inland water systems, producing noticeable increases in water temperatures. Rising temperatures, especially when combined with widespread nutrient pollution, directly favour the growth of toxic cyanobacteria. Climate changes have also altered natural water level fluctuations increasing the probability of extreme events as dry periods followed by heavy rains. The massive appearance of Dolichospermum lemmermannii ( = planktonic Anabaena), a toxic species absent from the pelagic zone of the subalpine oligotrophic Lake Maggiore before 2005, could be a consequence of the unusual fluctuations of lake level in recent years. We hypothesized that these fluctuations may favour the cyanobacterium as result of nutrient pulses from the biofilms formed in the littoral zone when the lake level is high. To help verify this, we exposed artificial substrates in the lake, and evaluated their nutrient enrichment and release after desiccation, together with measurements of fluctuations in lake level, precipitation and D. lemmermannii population. The highest percentage of P release and the lowest C:P molar ratio of released nutrients coincided with the summer appearance of the D. lemmermannii bloom. The P pulse indicates that fluctuations in level counteract nutrient limitation in this lake and it is suggested that this may apply more widely to other oligotrophic lakes. In view of the predicted increase in water level fluctuations due to climate change, it is important to try to minimize such fluctuations in order to mitigate the occurrence of cyanobacterial blooms.

The San Juan Delta, Colombia: tides, circulations, and salt dispersion

NASA Astrophysics Data System (ADS)

Restrepo, Juan D.; Kjerfve, Björn

2002-05-01

The San Juan River delta (Colombia) with an area of 800 km 2 is the largest delta environment on the Pacific coast of South America. It consists of active distributaries maintained by an average discharge of 2500 m 3 s -1, is tide dominated, and has relatively narrow estuarine mixing zones <17 km wide and typically ˜7 km wide. Water level and current time series in two distributary mouths indicate that the tide is semidiurnal with a form number 0.1-0.2 and a mean range of 3 m. Processes at tidal frequencies explain 75-95% of the water level variability with the remaining low-frequency variability attributed to meteorological forcing and river processes. The tidal phase for the main diurnal and semidiurnal constituents progress from north to south along the coast. Only the southernmost distributary experiences significant tidal asymmetry as a result of strong river discharge and shallow depths. In the northernmost distributary, shallow water constituents are insignificant. Tidal currents were more semidiurnal than the water level, with form number 0.09-0.13. Tidal ellipses indicated that currents were aligned with the channels and mean amplitudes <1 m s -1. In the delta distributaries, circulation modes varied from seaward flow at all depths during intermediate runoff conditions to gravitational circulation during rising and high discharge periods. In San Juan and Chavica distributaries, the currents were ebb-directed, while in Charambirá they were flood-directed. The circulation appears to be controlled by the morphology of the distributaries, which were weakly stratified and only sometimes moderately stratified. The net salt transport was directed seaward in San Juan and Charambirá, and landward at Chavica, indicating an imbalance in the salt budget, and signifying non-steady state behavior. The net longitudinal salt flux in the San Juan delta is largely a balance between ebb-directed advective flux, and flood-directed tidal sloshing. Along the distributary channels, fringing vegetation is controlled by freshwater discharge, longitudinal distribution of salinity, and morphology. In the most active distributaries, Chavica and San Juan, the vegetation setting is strongly shaped by the short estuarine zone, and mangroves only occur 5 km upstream of any distributary mouth, whereas in the tide-dominated distributaries, Charambirá and Cacahual, dense mangroves intrude 14 and 17 km upstream, respectively. Also, salt dispersion, tidal intrusion, salinity distribution, and mangrove extent in the San Juan delta agree qualitatively with the productive coastal fishery at the tide-dominated distributaries.

[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.

Status of water levels and selected water-quality conditions in the Sparta-Memphis aquifer in Arkansas, Spring-Summer 2003

USGS Publications Warehouse

Schrader, T.P.

2006-01-01

During the spring of 2003, water levels were measured in 341 wells in the Sparta-Memphis aquifer in Arkansas. Waterquality samples were collected for temperature and specificconductance measurements during the spring-summer of 2003 from 70 wells in Arkansas in the Sparta-Memphis aquifer. Maps of areal distribution of potentiometric surface, change in waterlevel measurements from 1999 to 2003, and specific-conductance data reveal spatial trends across the study area. The highest water-level altitude measured in Arkansas was 328 feet above National Geodetic Vertical Datum of 1929 (NGVD of 1929) in Craighead County; the lowest water-level altitude was 199 feet below NGVD of 1929 in Union County. Three large cones of depression are shown in the 2003 potentiometric surface map, centered in Columbia, Jefferson, and Union Counties in Arkansas as a result of large withdrawals for industrial and public supplies. A broad depression exists in western Poinsett County in Arkansas. The potentiometric surface indicates that large withdrawals have altered or reversed the natural direction of flow in most areas. In the northern third of the study area the flow is from the east, west, and north towards the broad depression in Poinsett County. In the central third of the study area the flow is dominated by the cone of depression centered in Jefferson County. In the southern third of the study area the flow is dominated by the two cones of depression in Union and Columbia Counties. A map of water-level changes from 1999 to 2003 was constructed using water-level measurements from 281 wells. The largest rise in water level measured was about 57.8 feet in Columbia County. The largest decline in water level measured was about -71.6 feet in Columbia County. Areas with a general rise are shown in Arkansas, Bradley, Calhoun, Cleveland, Columbia, Ouachita, and Union Counties. Areas with a general decline are shown in Craighead, Crittenden, Cross, Desha, Drew, Jefferson, Lonoke, Phillips, Poinsett, Prairie, and Woodruff Counties. Hydrographs were constructed for wells with a minimum of 25 years of water-level measurements. A trend line using a linear regression was calculated for the period of record from spring of 1978 to spring of 2003 to determine the annual decline or rise in feet per year for water levels in each well. The hydrographs were grouped by county. The mean values for county annual water-level decline or rise ranged from -1.42 to 0.27 foot per year. Specific conductance ranged from 82 microsiemens per centimeter at 25 degrees Celsius in Jefferson County to about 1,210 microsiemens per centimeter at 25 degrees Celsius in Lee County. The mean specific conductance was 400 microsiemens per centimeter at 25 degrees Celsius.

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.

Modeling Source Water Threshold Exceedances with Extreme Value Theory

NASA Astrophysics Data System (ADS)

Rajagopalan, B.; Samson, C.; Summers, R. S.

2016-12-01

Variability in surface water quality, influenced by seasonal and long-term climate changes, can impact drinking water quality and treatment. In particular, temperature and precipitation can impact surface water quality directly or through their influence on streamflow and dilution capacity. Furthermore, they also impact land surface factors, such as soil moisture and vegetation, which can in turn affect surface water quality, in particular, levels of organic matter in surface waters which are of concern. All of these will be exacerbated by anthropogenic climate change. While some source water quality parameters, particularly Total Organic Carbon (TOC) and bromide concentrations, are not directly regulated for drinking water, these parameters are precursors to the formation of disinfection byproducts (DBPs), which are regulated in drinking water distribution systems. These DBPs form when a disinfectant, added to the water to protect public health against microbial pathogens, most commonly chlorine, reacts with dissolved organic matter (DOM), measured as TOC or dissolved organic carbon (DOC), and inorganic precursor materials, such as bromide. Therefore, understanding and modeling the extremes of TOC and Bromide concentrations is of critical interest for drinking water utilities. In this study we develop nonstationary extreme value analysis models for threshold exceedances of source water quality parameters, specifically TOC and bromide concentrations. In this, the threshold exceedances are modeled as Generalized Pareto Distribution (GPD) whose parameters vary as a function of climate and land surface variables - thus, enabling to capture the temporal nonstationarity. We apply these to model threshold exceedance of source water TOC and bromide concentrations at two locations with different climate and find very good performance.

New insight on the water management in Ica Valley-Peru

NASA Astrophysics Data System (ADS)

Guttman, Joseph; Berger, Diego

2014-05-01

The Andes divide Peru into three natural drainage basins: Pacific basin, Atlantic basin and Lake Titicaca basin. According to the National Water Authority (ANA), the Pacific basin is the driest basin. The bulk of water that feed the local aquifers in the coastal Pacific region is coming from rivers that flow west from the Andes. One of them is the Ica River- source of the Ica Aquifer and the Pampas de Villacuri Aquifer. The Ica River flows in a graben that was created by a series of faults. The graben is filled with sand and gravel with interbeded and lenses of clay. The aquifer thickness varies between 25 meters to more than 200 meters. The Ica Valley has an extension of 7700 km2 and belongs to the Province of Ica, the second larger economic center in Peru. The Valley is located in the hyperarid region of the Southern Coastal area of Peru with a few millimeters of precipitation per year. The direct recharge is almost zero. The recharge into the Ica Valley aquifer is comes indirectly by infiltration of storm water through the riverbed generates in the Andes, through irrigation canals and by irrigation return flow. In this hyperarid region, local aquifers like the Ica Valley are extremely valuable resources to local populations and are the key sources of groundwater for agriculture and population needs. Therefore, these aquifers play a crucial role in providing people with water and intense attention should be given to manage the water sector properly and to keep the aquifer sustainable for future generations. The total pumping (from rough estimations) is much greater than the direct and indirect recharge. The deficit in the water balance is reflected in large water level decline, out of operation of shallow wells and the ascending of saline water from deeper layers. The change from flood irrigation that contributes about 35-40% of the water to the aquifer, to drip irrigation dramatically reduces the amount of water that infiltrates into the sub-surface from the irrigation canals and returns flow and increases the water balance deficit. In principal there are two ways to improve the hydrological conditions of the aquifers. One is to reduce dramatically the pumping from the aquifers to a level close to the calculated recharge. This will reduce the rate of decline of the water level and bring the aquifer to a new equilibrium. As there is no alternative source to bridge the gap in demand, this would lead to the collapse of local agriculture and thus is impractical. The second way is to improve (indirectly) the hydrological situation of the aquifers by artificially increasing the recharge into the aquifers together with encouraging sustainable water-based policies and restrictions on the drilling of new wells. Our recommendation is the second way to treat municipal effluents to a tertiary level and to recharge them along with excess runoff from the Ica River into the subsurface.

How propeller suction is the dominant factor for ship accidents at shallow water conditions

NASA Astrophysics Data System (ADS)

Acar, Dursun; Alpar, Bedri; Ozeren, Sinan

2017-04-01

The laminar flow comes to the fore with the disappearance of the several other directions in the internal displacements in the water current. Due to the dominant speed direction during the straightforward motion of the ship, the underwater hull is associated with the continuous flow of laminar currents. The open marine environment acts as a compressible liquid medium because of the presence of many variables about water volume overflow boundaries where the ship is associated. Layers of water rising over the sea surface due to ship's body and the propeller's water push provides loss of liquid lifting force for the ship. These situations change the well-known sea-floor morphology and reliable depth limits, and lead to probable accidents. If the ship block coefficient for the front side is 0.7 or higher, the "squat" will be more on the bow, because the associated factor "displacement volume" causes to the low-pressure environment due to large and rapid turbulence. Thus, the bow sinks further, which faced with liquid's weaker lift force. The vessels Gerardus Mercator, Queen Elizabeth and Costa Concordia had accidents because of unified reasons of squat, fast water mass displacement by hull push and propeller suction interaction. In the case of water mass displacement from the bow side away, that accident occurred in 2005 by the vessel Gerardus Mercator with excessive longitudinal trim angularity in the shallow water. The vessel Costa Concordia (2012), voluminous water displaced from the rear left side was an important factor because of the sharp manoeuvre of that the captain made before the accident. Observations before the accident indicate that full-speed sharp turn provided listed position for the ship from left (port side) in the direction of travel before colliding and then strike a rock on the sloping side of the seabed. The reason why the ship drifted to the left depends mainly the water discharge occurred at the left side of the hull during left-hand rudder control. Additionally the second water drainage from the shallow ridge area by the propeller's left-directed suction created a shallower environment. Similar situation for example collision of two ships during their side by side forward motions; their positions will be approached and listed to each other more same as downslope movement because of the shared area's water level collapse occur more by two propeller's suction.

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

Effects of Canals and Roads on Hydrologic Conditions and Health of Atlantic White Cedar at Emily and Richardson Preyer Buckridge Coastal Reserve, North Carolina, 2003-2006

USGS Publications Warehouse

Ferrell, Gloria M.; Strickland, A. Gerald; Spruill, Timothy B.

2007-01-01

The effects of canals and roads on hydrologic conditions and on the health of Atlantic white cedar at the Emily and Richardson Preyer Buckridge Coastal Reserve in North Carolina were evaluated by using data collected from the 1980s to 2006. Water levels were monitored along two transects established perpendicular to roads and canals in areas of healthy and unhealthy Atlantic white cedar as part of a study conducted from February 2003 through March 2006. Because of the low hydraulic gradient at the Reserve, the rate and direction of water movement are sensitive to disturbance. Canals increased drainage and contributed to lower water levels in some parts of the Reserve, whereas roads, depending on orientation, impeded drainage. Canals also appeared to facilitate movement of brackish water from the Alligator River into the interior of the Reserve during storms and wind tides. Data indicate that an influx of brackish water occurred in mid-September 2005 several days after the passage of Hurricane Ophelia. Although precipitation amounts and wind speeds associated with Hurricane Ophelia were not large, substantial changes in specific conductance occurred at the canal site on the unhealthy Atlantic white cedar transect. No corresponding increase in specific conductance was observed at the canal site on the healthy Atlantic white cedar transect. The specific conductance of water samples from canals and piezometers was highly correlated with concentrations of chloride and sodium. Ion ratios of some of the water samples, particularly samples with high specific conductance, were similar to those of seawater. Thermal and chemical stratification of water in the canals occurred during summer and winter months, and turnover and mixing occurred in the spring and fall. Upwelling of ground water as a result of excavation for roads did not appear to have a significant effect on the water quality of samples from the canals or piezometers. The specific conductance of water samples from piezometers installed in the root zone of healthy stands of Atlantic white cedar generally was lower than in water samples from unhealthy stands. This pattern also was observed in samples from piezometers installed on the transects and in other areas of the Reserve. Roads appear to have isolated some areas of the Reserve from the high-conductivity water in nearby canals. The paths by which brackish water entered the Reserve cannot be determined from the data obtained during this investigation. It appears that water can enter the Reserve from various directions, depending on wind patterns and water levels in the Alligator River.

21 CFR 173.395 - Trifluoromethane sulfonic acid.

Code of Federal Regulations, 2011 CFR

2011-04-01

... levels not to exceed 0.2 percent of the reaction mixture to catalyze the directed esterification. (c) The esterification reaction is quenched with steam and water and the catalyst is removed with the aqueous phase. Final traces of catalyst are removed by washing batches of the product three times with an aqueous...

21 CFR 173.395 - Trifluoromethane sulfonic acid.

Code of Federal Regulations, 2012 CFR

2012-04-01

... levels not to exceed 0.2 percent of the reaction mixture to catalyze the directed esterification. (c) The esterification reaction is quenched with steam and water and the catalyst is removed with the aqueous phase. Final traces of catalyst are removed by washing batches of the product three times with an aqueous...

21 CFR 173.395 - Trifluoromethane sulfonic acid.

Code of Federal Regulations, 2013 CFR

2013-04-01

... levels not to exceed 0.2 percent of the reaction mixture to catalyze the directed esterification. (c) The esterification reaction is quenched with steam and water and the catalyst is removed with the aqueous phase. Final traces of catalyst are removed by washing batches of the product three times with an aqueous...

Ground-water monitoring at Santa Barbara, California; Phase 2, Effects of pumping on water levels and on water quality in the Santa Barbara ground-water basin

USGS Publications Warehouse

Martin, Peter

1984-01-01

From July 1978 to January 1980, water levels in the southern part of the Santa Barbara ground-water basin declined more than 100 feet. These water-level declines resulted from increases in municipal pumping since July 1978. The increase in municipal pumping was part of a basin-testing program designed to determine the usable quantity of ground water in storage. The pumping, centered in the city less than 1 mile from the coast, has caused water-level declines to altitudes below sea level in the main water-bearing zones. As a result, the ground-water basin would be subject to saltwater intrusion if the study-period pumpage were maintained or increased. Data indicate that saltwater intrusion has degraded the quality of the water yielded from six coastal wells. During the study period, the six coastal wells all yielded water with chloride concentrations in excess of 250 milligrams per liter, and four of the wells yielded water with chloride concentrations in excess of 1,000 milligrams per liter. Previous investigators believed that saltwater intrusion was limited to the shallow part of the aquifer, directly adjacent to the coast. The possibility of saltwater intrusion into the deeper water-bearing deposits in the aquifer was thought to be remote because an offshore fault truncates these deeper deposits so that they lie against consolidated rocks on the seaward side of the fault. Results of this study indicate, however, that ocean water has intruded the deeper water-bearing deposits, and to a much greater extent than in the shallow part of the aquifer. Apparently the offshore fault is not an effective barrier to saltwater intrusion. No physical barriers are known to exist between the coast and the municipal well field. Therefore, if the pumping rate maintained during the basin-testing program were continued, the degraded water along the coast could move inland and contaminate the municipal supply wells. The time required for the degraded water to move from the coast to the nearest supply well is estimated, using Darcy's equation, to be about 20 years. Management alternatives for controlling saltwater intrusion in the Santa Barbara area include (1) decreasing municipal pumping, (2) increasing the quantity of water available for recharge by releasing surplus water from surface reservoirs to Mission Creek, (3) artificially recharging the basin using injection wells, and (4) locating municipal supply wells farther from the coast and spacing them farther apart in order to minimize drawdown. Continued monitoring of water levels and water quality would enable assessment of the effectiveness of the control measures employed.

Seasonal and Non-seasonal Sea Level Variations by Exchange of Water with Land Hydrology

NASA Technical Reports Server (NTRS)

Chao, Benjamin F.; Au, A. Y.

2004-01-01

The global ocean exchanges a large amount of water, seasonally or non-seasonally, with land hydrology. Apart from the long-term melting of ice sheets and glaciers, the water is exchanged directly as land runoff R, and indirectly via atmosphere in the form of precipitation minus evapo-transpiration P-E. On land, the hydrological budget balance is soil moisture S = P-E-R. The runoff R has been difficult to monitor; but now by combining the following two data sets one can obtain a global estimate, subject to the spatial and temporal resolutions afforded by the data: (1) The space gravity mission GRACE yields monthly S estimate on a spatial scale larger than approx. 1000 km over the last 2.5 years; (2) The atmospheric circulation model output, such as from NCEP, provides proxy estimates for P-E at monthly and approx. 200 km resolutions. We will discuss these estimates and the effects on the global ocean water budget and hence sea level.

Status of trace metals in surface seawater of the Gulf of Aqaba, Saudi Arabia.

PubMed

Al-Taani, Ahmed A; Batayneh, Awni; Nazzal, Yousef; Ghrefat, Habes; Elawadi, Eslam; Zaman, Haider

2014-09-15

The Gulf of Aqaba (GoA) is of significant ecological value with unique ecosystems that host one of the most diverse coral communities in the world. However, these marine environments and biodiversity have been threatened by growing human activities. We investigated the levels and distributions of trace metals in surface seawater across the eastern coast of the Saudi GoA. Zn, Cu, Fe, B and Se in addition to total dissolved solids and seawater temperature exhibited decreasing trends northwards. While Mn, Cd, As and Pb showed higher average levels in the northern GoA. Metal input in waters is dependent on the adjacent geologic materials. The spatial variability of metals in water is also related to wave action, prevailing wind direction, and atmospheric dry deposition from adjacent arid lands. Also, water discharged from thermal desalination plants, mineral dust from fertilizer and cement factories are potential contributors of metals to seawater water, particularly, in the northern GoA. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

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

Integration of research advances in modelling and monitoring in support of WFD river basin management planning in the context of climate change.

PubMed

Quevauviller, Philippe; Barceló, Damia; Beniston, Martin; Djordjevic, Slobodan; Harding, Richard J; Iglesias, Ana; Ludwig, Ralf; Navarra, Antonio; Navarro Ortega, Alícia; Mark, Ole; Roson, Roberto; Sempere, Daniel; Stoffel, Markus; van Lanen, Henny A J; Werner, Micha

2012-12-01

The integration of scientific knowledge about possible climate change impacts on water resources has a direct implication on the way water policies are being implemented and evolving. This is particularly true regarding various technical steps embedded into the EU Water Framework Directive river basin management planning, such as risk characterisation, monitoring, design and implementation of action programmes and evaluation of the "good status" objective achievements (in 2015). The need to incorporate climate change considerations into the implementation of EU water policy is currently discussed with a wide range of experts and stakeholders at EU level. Research trends are also on-going, striving to support policy developments and examining how scientific findings and recommendations could be best taken on board by policy-makers and water managers within the forthcoming years. This paper provides a snapshot of policy discussions about climate change in the context of the WFD river basin management planning and specific advancements of related EU-funded research projects. Perspectives for strengthening links among the scientific and policy-making communities in this area are also highlighted. Copyright © 2012 Elsevier B.V. All rights reserved.

Status of ground-water levels and storage volume in the Equus Beds aquifer near Wichita, Kansas, January 2000-January 2003

USGS Publications Warehouse

Hansen, Cristi V.; Aucott, Walter R.

2004-01-01

The Equus Beds aquifer northwest of Wichita, Kansas, was developed to supply water to Wichita residents and for irrigation in south-central Kansas beginning on September 1, 1940. Ground-water pumping for city and agricultural use from the aquifer caused water levels to decline in a large part of the area. Irrigation pumpage in the area increased substantially during the 1970s and 1980s and accelerated water-level declines. A period of water-level rises associated with greater-than-average precipitation and decreased city pumpage from the study area began in 1993. An important factor in the decreased city pumpage was increased use of Cheney Reservoir as a water-supply source by the city of Wichita; as a result, city pumpage from the Equus Beds aquifer during 1993-2002 went from being greater than one-half to slightly less than one-third of Wichita's water usage. Since 1995, the city also has been investigating the use of artificial recharge in the study area to meet future water-supply needs and to protect the aquifer from the intrusion of saltwater from natural and human-related sources to the west. During January 2003, the direction of ground-water flow in the Equus Beds aquifer in the area was generally from west to east similar to predevelopment of the aquifer. The maximum water-level decline since 1940 for the period January 2000 to January 2003 was 29.54 feet in July 2002 at well 3 in the northern part of the area. Cumulative water-level changes from January 2000 to January 2003 typically were less than 4 feet with rises of less than 4 feet common in the central part of the area; however, declines of more than 4 feet occurred in the northwestern and southern parts of the area. The recovery of water levels and aquifer storage volumes from record low levels in October 1992 generally continued to April 2000. The recovery of about 182,000 acre-feet of storage volume in the area from October 1992 to April 2000 represents about a 64-percent recovery of the storage depletion that occurred from August 1940 to October 1992. About 47 percent of this recovery was lost from April 2000 to October 2002 when storage volume in the area decreased by about 86,000 acre-feet. Major contributors to the decreases in water levels and storage volumes were reduced recharge associated with precipitation that was less than in the preceding 5 years and increased irrigation pumpage. The loss of storage probably would have been larger if the continued decrease in city pumpage, which is closely associated with the water-level rises in the central part of the study area, and increased city use of water from Cheney Reservoir had not occurred. The effect of artificial recharge on water levels and storage volume probably was masked by the generally larger decreases in city pumpage in the area.

European union water policy--tasks for implementing "Water Framework Directive" in pre-accession countries.

PubMed

Sözen, Seval; Avcioglu, Ebru; Ozabali, Asli; Görgun, Erdem; Orhon, Derin

2003-08-01

Water Framework Directive aiming to maintain and improve the aquatic environment in the EU was launched by the European Parliament in 2000. According to this directive, control of quantity is an ancillary element in securing good water quality and therefore measures on quantity, serving the objective of ensuring good quality should also be established. Accordingly, it is a comprehensive and coordinated package that will ensure all European waters to be protected according to a common standard. Therefore, it refers to all other Directives related to water resources management such as Urban Wastewater Treatment Directive Nitrates Directive, Drinking Water Directive, Integrated Pollution Prevention Control etc. Turkey, as a candidate state targeting full-membership, should comply the necessary preparations for the implementation of the "Water Framework Directive" as soon as possible. In this study, the necessary legislative, political, institutional, and technical attempts of the pre-accession countries have been discussed and effective recommendations have been offered for future activities in Turkey.

An Update of Hydrologic Conditions and Distribution of Selected Constituents in Water, Snake River Plain Aquifer and Perched-Water Zones, Idaho National Laboratory, Idaho, Emphasis 2002-05

USGS Publications Warehouse

Davis, Linda C.

2008-01-01

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds, evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the Snake River Plain aquifer and perched-water zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched-water zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched-water wells in the USGS ground-water monitoring networks during 2002-05. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged primarily from infiltration of irrigation water, infiltration of streamflow, ground-water inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2001 to March-May 2005, water levels in wells declined throughout the INL area. The declines ranged from about 3 to 8 feet in the southwestern part of the INL, about 10 to 15 feet in the west central part of the INL, and about 6 to 11 feet in the northern part of the INL. Water levels in perched water wells declined also, with the water level dropping below the bottom of the pump in many wells during 2002-05. For radionuclides, concentrations that equal 3s, wheres s is the sample standard deviation, represent a measurement at the minimum detectable concentration, or 'reporting level'. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2002-05. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In October 2005, reportable concentrations of tritium in ground water ranged from 0.51+or-0.12 to 11.5+or-0.6 picocuries per milliliter and the tritium plume extended south-southwestward in the general direction of ground-water flow. Tritium concentrations in water from several wells southwest of the Idaho Nuclear Technology and Engineering Center (INTEC) decreased or remained constant as they had during 1998-2001, with the exception of well USGS 47, which increased a few picocuries per milliliter. Most wells completed in shallow perched water at the Reactor Technology Complex (RTC) were dry during 2002---05. Tritium concentrations in deep perched water exceeded the reporting level in nine wells at the RTC. The tritium concentration in water from one deep perched water well exceeded the reporting level at the INTEC. Concentrations of strontium-90 in water from 14 of 34 wells sampled during October 2005 exceeded the reporting level. Concentrations ranged from 2.2+or-0.7 to 33.1+or-1.2 picocuries per liter. However, concentrations from most wells remained relatively constant or decreased since 1989. Strontium-90 has not been detected within the eastern Snake River Plain aquifer beneath the RTC partly because of the exclusive use of waste-disposal ponds and lined evaporation ponds rather than the disposal well for radioactive-wastewater disposal at RTC. At the RTC, strontium-90 concentrations in water from six wells completed in deep perched ground water exceeded the reporting level during 2002-05. At the INTEC, the reporting level was exceeded in water from three wells completed in deep perched ground water. During 2002-05, concentrations of plutonium-238, and plutonium-239, -240 (undivided), and americium-241 were less than the reporting level in water samples from all wells sampled at the INL. During 2002-05, concentrations of cesium-137 in water from all wells sa

Cations and anions in drinking water as putative contributory factors to endemic goitre in Plateau State, Nigeria.

PubMed

Das, S C; Isichei, U P; Egbuta, J O; Banwo, A I

1989-10-01

The prevalence of endemic goitre in Plateau State, Nigeria was established and an attempt was made to identify some of the possible environmental goitrogenic agents in the region to establish their likely relationship with the goitre endemicity. Iodine deficiency appears to be a major aetiological factor for the disease as indicated by low iodine levels observed in portable drinking water and in daily urinary excretion. The carbonate (CO3-) content of drinking water supply was found to bear a significant positive correlation with the goitre rate for the entire state (p less than 0.005). The calcium (Ca++) and magnesium (Mg++) levels of the drinking water also exhibited relatively good linear direct correlations with the percentage goitre distribution in a region, nearly 2/3 of the state. It is concluded that there is possibly an interplay of several factors and in particular the carbonate content of drinking water which, in association with a state of iodine deficiency, may be regarded as responsible for the goitre endemic seen in this part of the Continental Africa.

Determination of picomolar concentrations of carbonyl compounds in natural waters, including seawater, by liquid chromatography

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

Kieber, R.; Mopper, K.

1990-10-01

Low molecular weight carbonyl compounds in natural waters were determined at picomolar to nanomolar levels by derivatization with 2,4-dinitrophenylhydrazine followed by liquid chromatography. The uniqueness of the method is attributed to the extremely low blanks obtained and the minimal sample preparation involved. The detection limit for direct injection of derivatized natural water samples is 0.5 nM for aldehydes and 5 nM for ketones with a precision of {approximately}7% RSD at the 30 nM level for aldehydes. The detection limit can be further lowered by using off-line cartridge enrichment in which derivatized natural water is passed through a C18 extraction cartridge.more » Recoveries for the enrichment method were 95-105% for a sample volume of 20 mL and for concentrations of carbonyl compounds in the 1-30 nM range. A field procedure for storage of derivatized sample extracts for extended periods is also presented. Applications of enrichment and sample storage techniques to marine and estuarine waters are presented.« less

Tidal truncation and barotropic convergence in a channel network tidally driven from opposing entrances

USGS Publications Warehouse

Warner, J.C.; Schoellhamer, D.; Schladow, G.

2003-01-01

Residual circulation patterns in a channel network that is tidally driven from entrances on opposite sides are controlled by the temporal phasing and spatial asymmetry of the two forcing tides. The Napa/Sonoma Marsh Complex in San Francisco Bay, CA, is such a system. A sill on the west entrance to the system prevents a complete tidal range at spring tides that results in tidal truncation of water levels. Tidal truncation does not occur on the east side but asymmetries develop due to friction and off-channel wetland storage. The east and west asymmetric tides meet in the middle to produce a barotropic convergence zone that controls the transport of water and sediment. During spring tides, tidally averaged water-surface elevations are higher on the truncated west side. This creates tidally averaged fluxes of water and sediment to the east. During neap tides, the water levels are not truncated and the propagation speed of the tides controls residual circulation, creating a tidally averaged flux in the opposite direction. ?? 2003 Elsevier Science B.V. All rights reserved.

Implementing the water framework directive: contract design and the cost of measures to reduce nitrogen pollution from agriculture.

PubMed

Bartolini, Fabio; Gallerani, Vittorio; Raggi, Meri; Viaggi, Davide

2007-10-01

The performance of different policy design strategies is a key issue in evaluating programmes for water quality improvement under the Water Framework Directive (60/2000). This issue is emphasised by information asymmetries between regulator and agents. Using an economic model under asymmetric information, the aim of this paper is to compare the cost-effectiveness of selected methods of designing payments to farmers in order to reduce nitrogen pollution in agriculture. A principal-agent model is used, based on profit functions generated through farm-level linear programming. This allows a comparison of flat rate payments and a menu of contracts developed through mechanism design. The model is tested in an area of Emilia Romagna (Italy) in two policy contexts: Agenda 2000 and the 2003 Common Agricultural Policy (CAP) reform. The results show that different policy design options lead to differences in policy costs as great as 200-400%, with clear advantages for the menu of contracts. However, different policy scenarios may strongly affect such differences. Hence, the paper calls for greater attention to the interplay between CAP scenarios and water quality measures.

Implementing the Water Framework Directive: Contract Design and the Cost of Measures to Reduce Nitrogen Pollution from Agriculture

NASA Astrophysics Data System (ADS)

Bartolini, Fabio; Gallerani, Vittorio; Raggi, Meri; Viaggi, Davide

2007-10-01

The performance of different policy design strategies is a key issue in evaluating programmes for water quality improvement under the Water Framework Directive (60/2000). This issue is emphasised by information asymmetries between regulator and agents. Using an economic model under asymmetric information, the aim of this paper is to compare the cost-effectiveness of selected methods of designing payments to farmers in order to reduce nitrogen pollution in agriculture. A principal-agent model is used, based on profit functions generated through farm-level linear programming. This allows a comparison of flat rate payments and a menu of contracts developed through mechanism design. The model is tested in an area of Emilia Romagna (Italy) in two policy contexts: Agenda 2000 and the 2003 Common Agricultural Policy (CAP) reform. The results show that different policy design options lead to differences in policy costs as great as 200-400%, with clear advantages for the menu of contracts. However, different policy scenarios may strongly affect such differences. Hence, the paper calls for greater attention to the interplay between CAP scenarios and water quality measures.

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

Upstream water resource management to address downstream pollution concerns: A policy framework with application to the Nakdong River basin in South Korea

NASA Astrophysics Data System (ADS)

Yoon, Taeyeon; Rhodes, Charles; Shah, Farhed A.

2015-02-01

An empirical framework for assisting with water quality management is proposed that relies on open-source hydrologic data. Such data are measured periodically at fixed water stations and commonly available in time-series form. To fully exploit the data, we suggest that observations from multiple stations should be combined into a single long-panel data set, and an econometric model developed to estimate upstream management effects on downstream water quality. Selection of the model's functional form and explanatory variables would be informed by rating curves, and idiosyncrasies across and within stations handled in an error term by testing contemporary correlation, serial correlation, and heteroskedasticity. Our proposed approach is illustrated with an application to the Nakdong River basin in South Korea. Three alternative policies to achieve downstream BOD level targets are evaluated: upstream water treatment, greater dam discharge, and development of a new water source. Upstream water treatment directly cuts off incoming pollutants, thereby presenting the smallest variation in its downstream effects on BOD levels. Treatment is advantageous when reliability of water quality is a primary concern. Dam discharge is a flexible tool, and may be used strategically during a low-flow season. We consider development of a new water corridor from an extant dam as our third policy option. This turns out to be the most cost-effective way for securing lower BOD levels in the downstream target city. Even though we consider a relatively simple watershed to illustrate the usefulness of our approach, it can be adapted easily to analyze more complex upstream-downstream issues.

Disaggregating residential water demand for improved forecasts and decision making

NASA Astrophysics Data System (ADS)

Woodard, G.; Brookshire, D.; Chermak, J.; Krause, K.; Roach, J.; Stewart, S.; Tidwell, V.

2003-04-01

Residential water demand is the product of population and per capita demand. Estimates of per capita demand often are based on econometric models of demand, usually based on time series data of demand aggregated at the water provider level. Various studies have examined the impact of such factors as water pricing, weather, and income, with many other factors and details of water demand remaining unclear. Impacts of water conservation programs often are estimated using simplistic engineering calculations. Partly as a result of this, policy discussions regarding water demand management often focus on water pricing, water conservation, and growth control. Projecting water demand is often a straight-forward, if fairly uncertain process of forecasting population and per capita demand rates. SAHRA researchers are developing improved forecasts of residential water demand by disaggregating demand to the level of individuals, households, and specific water uses. Research results based on high-resolution water meter loggers, household-level surveys, economic experiments and recent census data suggest that changes in wealth, household composition, and individual behavior may affect demand more than changes in population or the stock of landscape plants, water-using appliances and fixtures, generally considered the primary determinants of demand. Aging populations and lower fertility rates are dramatically reducing household size, thereby increasing the number of households and residences for a given population. Recent prosperity and low interest rates have raised home ownership rates to unprecented levels. These two trends are leading to increased per capita outdoor water demand. Conservation programs have succeeded in certain areas, such as promoting drought-tolerant native landscaping, but have failed in other areas, such as increasing irrigation efficiency or curbing swimming pool water usage. Individual behavior often is more important than the household's stock of water-using fixtures, and ranges from hedonism (installing pools and whirlpool tubs) to satisficing (adjusting irrigation timers only twice per year) to acting on deeply-held conservation ethics in ways that not only fail any benefit-cost test, but are discouraged, or even illegal (reuse of gray water and black water). Research findings are being captured in dynamic simulation models that integrate social and natural science to create tools to assist water resource managers in providing sustainable water supplies and improving residential water demand forecasts. These models feature simple, graphical user interfaces and output screens that provide decision makers with visual, easy-to-understand information at the basin level. The models reveal connections between various supply and demand components, and highlight direct impacts and feedback mechanisms associated with various policy options.

Climatic sensitivity, water-use efficiency, and growth decline in boreal jack pine (Pinus banksiana) forests in Northern Ontario

NASA Astrophysics Data System (ADS)

Dietrich, Rachel; Bell, F. Wayne; Silva, Lucas C. R.; Cecile, Alice; Horwath, William R.; Anand, Madhur

2016-10-01

Rises in atmospheric carbon dioxide (atmCO2) levels are known to stimulate photosynthesis and increase intrinsic water-use efficiency (iWUE) in trees. Stand-level increases in iWUE depend on the physiological response of dominant species to increases in atmCO2, while tree-level response to increasing atmCO2 depends on the balance between the direct effects of atmCO2 on photosynthetic rate and the indirect effects of atmCO2 on drought conditions. The aim of this study was to characterize the response of boreal jack pine (Pinus banksiana) stands in Northern Ontario to changes in atmCO2 and associated climatic change over the past 100 years. The impact of changes in growing season length, temperature, and precipitation, as well as atmCO2 on tree growth, was determined using stable carbon isotopes and dendrochronological analysis. Jack pine stands in this study were shown to be in progressive decline. As expected, iWUE was found to increase in association with rising atmCO2. However, increases in iWUE were not directly coupled with atmCO2, suggesting that the degree of iWUE improvement is limited by alternative factors. Water-use efficiency was negatively associated with tree growth, suggesting that warming- and drought-induced stomatal closure has likely led to deviations from expected atmCO2-enhanced growth. This finding corroborates that boreal forest stands are likely to face continued stress under future climatic warming.

Direct Measurements of Water Canopy Storage Capacity of Broadleaf Shrubs under Different Temperature and Wetting Regimes

NASA Astrophysics Data System (ADS)

Yerk, W.

2016-12-01

It is generally agreed that canopy water storage capacity is one of the defining factors of rainfall interception. Multiple studies of storage capacity by shrubs have been published. However, only a fraction of species have been studied. In the presented study the storage capacity of five species (Aronia melanocarpa, Cornus sericea, Hydrangea quercifolia, Itea virginica, and Prunus laurocerasus) was directly measured in an indoor experiment. Effect of the water temperature on the amount of water stored by the canopy was also investigated. Five branches of each species (length 0.25-0.60 m, LAI 1.3-3.6) were selected. Methods of full submergence in water and a simulated rain of intensity of 187.5±9.9 mm/hr were applied. Water of two different temperatures of 30°C and 1.5°C was used for the submergence method. Weight of the branches fixated in a natural position was measured with a digital balance. Storage capacity was expressed as a depth of water retained by the entire branch divided by the one-sided area of all leaves. The storage capacity obtained by submergence was 0.45±0.5 mm for A. melanocarpa, 0.33±0.03 mm for C. sericea, 0.40±0.02 mm for H. quercifolia, 0.48±0.05 mm for I. virginica, and 0.67±0.09 mm for P. laurocerasus. Difference in the storage capacities obtained by both methods was inconsistent. Water temperature exerted a more pronounced effect on the capacity. The canopies stored 0.01 to 0.05 mm more water (p-value < 0.005 for all species except A. melanocarpa). Our findings correspond with the range of storage capacity reported for shrub species. The directly measured storage capacity exceeds the widely used in hydrological modeling value of 0.2 mm. We were able to detect an increase of capacity to store cold water; however, the increase was below the practical level.

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.

Cadmium determination in natural waters at the limit imposed by European legislation by isotope dilution and TiO2 solid-phase extraction.

PubMed

García-Ruiz, Silvia; Petrov, Ivan; Vassileva, Emilia; Quétel, Christophe R

2011-11-01

The cadmium content in surface water is regulated by the last European Water Framework Directive to a maximum between 0.08 and 0.25 μg L(-1) depending on the water type and hardness. Direct measurement of cadmium at this low level is not straightforward in real samples, and we hereby propose a validated method capable of addressing cadmium content below μg L(-1) level in natural water. It is based on solid-phase extraction using TiO(2) nanoparticles as solid sorbent (0.05 g packed in mini-columns) to allow the separation and preconcentration of cadmium from the sample, combined to direct isotope dilution and detection by inductively coupled plasma mass spectrometry (ID-ICP-MS). The extraction setup is miniaturised and semi-automated to reduce risks of sample contamination and improve reproducibility. Procedural blanks for the whole measurement process were 5.3 ± 2.8 ng kg(-1) (1 s) for 50 g of ultrapure water preconcentrated ten times. Experimental conditions influencing the separation (including loading pH, sample flow rates, and acid concentration in the eluent) were evaluated. With isotope dilution the Cd recovery rate does not have to be evaluated carefully. Moreover, the mathematical model associated to IDMS is known, and provides transparency for the uncertainty propagation. Our validation protocol was in agreement with guidelines of the ISO/IEC 17025 standard (chapter 5.4.5). Firstly, we assessed the experimental factors influencing the final result. Secondly, we compared the isotope ratios measured after our separation procedure to the reference values obtained with a different protocol for the digested test material IMEP-111 (mineral feed). Thirdly, we analysed the certified reference material BCR-609 (groundwater). Finally, combined uncertainties associated to our results were estimated according to ISO-GUM guidelines (typically, 3-4% k = 2 for a cadmium content of around 100 ng kg(-1)). We applied the developed method to the groundwater and wastewater samples ERM-CA615 and BCR-713, respectively, and results agreed with certificate values within uncertainty statements.

Short-Range Acoustic Propagation Using Mobile Transmitters Under Arctic Ice Cover

DTIC Science & Technology

2017-09-01

predict the surface water/ice scattering and absorptive effects on transmitted sound . In addition, sound speed variability by range (usually...receivers at ranges out to 10 kilometers. Sound speed profile data was also measured on site. Transmission loss models were created as a baseline at the...received sound level (on the level of 30 to 40 decibels) at the same range and depth but different directions. 14. SUBJECT TERMS Arctic, Beaufort Sea

Recharge source identification using isotope analysis and groundwater flow modeling for Puri city in India

NASA Astrophysics Data System (ADS)

Nayak, P. C.; Vijaya Kumar, S. V.; Rao, P. R. S.; Vijay, T.

2017-11-01

The holy city of Lord Jagannath is situated on the sea shore of the Bay of Bengal in Odisha state in India. Puri is a city of high religious importance and heritage value, details of the rituals, fairs, and festivals, and related aspects are covered extensively. It is found that water levels in two wells (Ganga and Yamuna) are declining and the causes are studied by undertaking modeling study of rainfall-recharge processes, surface water-groundwater interactions, and increasing demands due to urbanization at basin scale. Hydrochemical analysis of groundwater samples indicates that pH value is varying from 7 to 8.4 and electrical conductivity (EC) is found in between 238 and 2710 μmhos/cm. The EC values indicate that the shallow groundwater in Puri is not saline. Stable isotopic signatures of O-18, Deuterium indicate two different sources are active in the city area. In most of the handpumps, water recharged by the surface water sources. From the current investigation, it is evident that in a few handpumps and most of the dug-wells, isotopic signatures of water samples resembles with local precipitation. The groundwater recharge is taking place from the north-southern direction. Visual MODFLOW has been used for studying groundwater aspects and different scenarios have been developed. It is suggested to maintain water level in Samang Lake to restore depletion in groundwater level in two wells.

Report on the Comprehensive Survey of the Water Resources of the Delaware River Basin. Volume 8. Appendix O

DTIC Science & Technology

1960-12-01

disposed into the sewers provided that the material is soluble. (2) Radioactive levels include the following: strontium 90 or polonium 210 , not to...abundance can have a direct effect upon animal populations dependent upon them for food , the quantity and quality of the zooplankton is one index to the...obtain further data on the effect on crops of irrigation with primary effluent and to evaluate operating problems directly related to public health

Groundwater-quality data from the eastern Snake River Plain Aquifer, Jerome and Gooding Counties, south-central Idaho, 2017

USGS Publications Warehouse

Skinner, Kenneth D.

2018-05-11

Groundwater-quality samples and water-level data were collected from 36 wells in the Jerome/Gooding County area of the eastern Snake River Plain aquifer during June 2017. The wells included 30 wells sampled for the U.S. Geological Survey’s National Water-Quality Assessment project, plus an additional 6 wells were selected to increase spatial distribution. The data provide water managers with the ability for an improved understanding of groundwater quality and flow directions in the area. Groundwater-quality samples were analyzed for nutrients, major ions, trace elements, and stable isotopes of water. Quality-assurance and quality-control measures consisted of multiple blank samples and a sequential replicate sample. All data are available online at the USGS National Water Information System.

Groundwater-surface water relations in the Fox River watershed: insights from exploratory studies in Illinois and Wisconsin

USGS Publications Warehouse

Mills, Patrick C.

2014-01-01

Exploratory studies were conducted at sites bordering the Fox River in Waukesha, Wisconsin, during 2010 and McHenry, Illinois, during 2011–13. The objectives of the studies were to assess strategies for the study of and insights into the potential for directly connected groundwater and surface-water systems with natural groundwater discharge to streams diverted and (or) streamflow induced (captured) by nearby production-well withdrawals. Several collection efforts of about 2 weeks or less provided information and data on site geology, groundwater and surface-water levels, hydraulic gradients, water-temperature and stream-seepage patterns, and water chemistry including stables isotopes. Overview information is presented for the Waukesha study, and selected data and preliminary findings are presented for the McHenry study.

Calcium nephrolithiasis: effect of water hardness on urinary electrolytes.

PubMed

Schwartz, Bradley F; Schenkman, Noah S; Bruce, Jeremy E; Leslie, Stephen W; Stoller, Marshall L

2002-07-01

To analyze the impact of water hardness from public water supplies on calcium stone incidence and 24-hour urine chemistries in patients with known calcium urinary stone formation. Patients are frequently concerned that their public water supply may contribute to urinary stone disease. Investigators have documented an inverse relationship between water hardness and calcium lithogenesis. Others have found no such association. Patients who form calcium stones (n = 4833) were identified geographically by their zip code. Water hardness information from distinct geographic public water supplies was obtained, and patient 24-hour urine chemistries were evaluated. Drinking water hardness was divided into decile rankings on the basis of the public water supply information obtained from the Environmental Protection Agency. These data were compared with patient questionnaires and 24-hour urine chemistries. The calcium and magnesium levels in the drinking water were analyzed as independent variables. The number of total lifetime stone episodes was similar between patients residing in areas with soft public water and hard public water. Patients consuming the softest water decile formed 3.4 lifetime stones and those who consumed the hardest water developed 3.0 lifetime stones (P = 0.0017). The 24-hour urine calcium, magnesium, and citrate levels increased directly with drinking water hardness, and no significant change was found in urinary oxalate, uric acid, pH, or volume. The impact of water hardness on urinary stone formation remains unclear, despite a weak correlation between water hardness and urinary calcium, magnesium, and citrate excretion. Tap water, however, can change urinary electrolytes in patients who form calcium stones.

Rooftop level rainwater harvesting system

NASA Astrophysics Data System (ADS)

Traboulsi, Hayssam; Traboulsi, Marwa

2017-05-01

Unfortunately, in Lebanon and other countries in the Middle East region, water becomes scarcer than ever before, and over the last decades the demand on domestic water has increased due to population and economic growth. Although rainwater harvesting is considered to be a safe and reliable alternative source for domestic water, the inconvenience or impracticalities related to the cost and space needed for the construction of ground or underground storage tanks makes this practice not widely common in rural areas and rarely implemented in urban cities. This paper introduces a new technique to rainwater harvesting which can be easily used in both rural and urban areas: it collects and stores rainwater directly in tanks already installed on building roofs and not necessarily in special ground or underground ones. If widely adopted in Lebanon, this technique could help in: (1) collecting around 23 MCM (70 % of the current deficit in the domestic water supply) of rainwater and thus increasing the available water per m2 of building by 0.4 m3 per year, (2) saving around 7 % of the amount of electric energy usually needed to pump water from an aquifer well and ground or underground tank, and (3) considerably reducing the rate of surface runoff of rainwater at the coastal zones where rainwater is not captured at all and goes directly to the sea.

Air-water gas exchange of chlorinated pesticides in four lakes spanning a 1,205 meter elevation range in the Canadian Rocky Mountains.

PubMed

Wilkinson, Andrew C; Kimpe, Lynda E; Blais, Jules M

2005-01-01

Concentrations of selected persistent organic pollutants (POPs) in air and water were measured from four lakes that transect the Canadian Rocky Mountains. These data were used in combination with wind velocity and temperature-adjusted Henry's law constants to estimate the direction and magnitude of chemical exchange across the air-water interface of these lakes. Bow Lake (1,975 m above sea level [masl]) was studied during the summers of 1998 through 2000; Donald (770 masl) was studied during the summer of 1999; Dixon Dam Lake (946 masl) and Kananaskis Lake (1,667 masl) were studied during the summer of 2000. Hexachlorobenzene (HCB) and dieldrin volatilized from Bow Lake in spring and summer of 1998 to 2000 at a rate of 0.92 +/-1.1 and 0.55+/-0.37 ng m(-2) d(-1), respectively. The alpha-endosulfan deposited to Bow Lake at a rate of 3.4+/-2.2 ng m(-2) d(-1). Direction of gas exchange for gamma-hexachlorocyclohexane (gamma-HCH) changed from net deposition in 1998 to net volatilization in 1999, partly because of a surge in y-HCH concentrations in the water at Bow Lake in 1999. Average gamma-HCH concentrations in air declined steadily over the three-year period, from 0.021 ng m(-3) in 1998, to 0.0023 ng m(-3) in 2000, and to volatilization in 1999 and 2000. Neither the concentrations of organochlorine compounds (OCs) in air and water, nor the direction and rate of air-water gas exchange correlate with temperature or elevation. In general, losses of pesticides by outflow were greater than the amount exchanged across the air-water interface in these lakes.

Eye wash water flow direction study: an evaluation of the effectiveness of eye wash devices with opposite directional water flow.

PubMed

Fogt, Jennifer S; Jones-Jordan, Lisa A; Barr, Joseph T

2018-01-01

New designs of eye wash stations have been developed in which the direction of water flow from the fountain has been reversed, with two water streams originating nasally in both eyes and flowing toward the temporal side of each eye. No study has been done to determine the ideal direction of water flow coming from the eye wash in relation to the eye. Ophthalmic eye examinations were conducted before and after the use of two eye wash stations with opposite water flow directionality. Fluorescein was instilled in both eyes before using an eye wash to measure the effectiveness of the water flow. Subjects were surveyed upon their experiences using the eye washes. Ophthalmic examination found no significant difference in the efficacy of the eye washes with nasal-to-temporal water flow when compared to temporal-to-nasal water flow direction.

Ground-water quality, levels, and flow direction near Fort Cobb Reservoir, Caddo County, Oklahoma, 1998-2000

USGS Publications Warehouse

Becker, Carol J.

2001-01-01

Fort Cobb Reservoir in northwest Caddo County Oklahoma is managed by the Bureau of Reclamation for water supply, recreation, flood control, and wildlife. Excessive amounts of nitrogen in the watershed have the potential to cause long-term eutrophication of the reservoir and increase already elevated concentrations of nitrogen in the Rush Springs aquifer. The U.S. Geological Survey in cooperation with the Bureau of Reclamation studied ground water in the area surrounding a swine feeding operation located less than 2 miles upgradient from Fort Cobb Reservoir in Caddo County, Oklahoma. Objectives of the study were to (1) determine if the operation was contributing nitrogen to the ground water and (2) measure changes in ground-water levels and determine the local ground-water flow direction in the area surrounding the swine feeding operation. Nitrate concentrations (28.1 and 31.5 milligrams per liter) were largest in two ground-water samples from a well upgradient of the wastewater lagoon. Nitrate concentrations ranged from 4.30 to 8.20 milligrams per liter in samples from downgradient wells. Traces of ammonia and nitrite were detected in a downgradient well, but not in upgradient wells. d15N values indicate atmospheric nitrogen, synthetic fertilizer, or plants were the predominate sources of nitrate in ground water from the downgradient wells. The d15N values in these samples are depleted in nitrogen-15, indicating that animal waste was not a significant contributor of nitrate. Manganese concentrations (1,150 and 965 micrograms per liter) in samples from a downgradient well were substantially larger than concentrations in samples from other wells, exceeding the secondary drinking-water standard of 50 micrograms per liter. Larger concentrations of bicarbonate, magnesium, fluoride, and iron and a higher pH were also measured in water from a downgradient well. Ground-water levels in an observation well were higher from April to mid-July and lower during the late summer and in the fall due to a seasonal decrease in precipitation, increase in water withdrawals, and increase in evapotranspiration. Ground water near the wastewater spray field moved south-southeast toward Willow Creek along a gradient of about 50 feet per mile. Analysis of ground-water samples suggest that commercial fertilizer is contributing nitrate upgradient of the swine feeding operation and that wastewater from the lagoon is contributing reduced forms of nitrogen, ammonia and nitrite. Additional downgradient wells would be needed to (1) determine if the swine feeding operation is adding excessive amounts of nitrogen to ground water, (2) determine the vertical dimension of wastewater flow, and (3) the extent of wastewater downgradient of the lagoon.

A methodological approach to understand functional relationships between ecological indices and human-induced pressures: the case of the Posidonia oceanica meadows.

PubMed

Bacci, Tiziano; Rende, Sante Francesco; Penna, Marina; Trabucco, Benedetta; Montefalcone, Monica; Cicero, Anna Maria; Giovanardi, Franco

2013-11-15

The European Water Framework Directive (WFD) 2000/60/EC requests the achievement of the Good Status for all surface waters, including the coastal waters, by 2015. In order to check compliance with the needs of Directive, Italian national monitoring data on Posidonia oceanica meadows have been explored and the relationships among the Posidonia Rapid and Easy Index (PREI), and human-induced pressures have been analyzed along the Italian coasts. The aim of this work is to establish functional relationships between a response variable (i.e. the PREI) and a set of potential pressure (i.e. land use, potential organic and nutrient loading, pesticides) and status (i.e. transparency, trophic level and stability of the water column) indicators in a quantitative way. The ecological responses of coastal marine environment have been evaluated using appropriate statistical tools, such as the multiple linear regression analyses and "linear programming" techniques. Results show that more than 70% of the variability of the P. oceanica meadows status, expressed as PREI value, is significantly explained only by a few pressure/status indicators (namely: potential organic load, specific nitrogen load, natural areas extent, water column transparency), among all those initially considered in the model. The application of the proposed model could allow decision makers to better address remedial actions and to achieve the environmental targets proposed by the EU Directives. Copyright © 2013 Elsevier Ltd. All rights reserved.

Agricultural pollution control under Spanish and European environmental policies

NASA Astrophysics Data System (ADS)

MartíNez, Yolanda; Albiac, José

2004-10-01

Nonpoint pollution from agriculture is an important environmental policy issue in Spain and the European Union. Agricultural pollution in Spain is being addressed by the National Irrigation Plan and by the European Water Framework Directive. This article contributes to the ongoing policy decision process by analyzing nonpoint pollution control and presenting results on the efficiency of abatement measures. Results question the reliance of the Water Framework Directive on water pricing as a pollution instrument for reaching good status for all waters because higher water prices close to full recovery cost advocated by the directive appear to be inefficient as an emission control instrument. Another important result is that abatement measures based on input taxes and standards on nitrogen appear to be more suitable than the National Irrigation Plan subsidies designed to promote irrigation investments. The results also contribute with further evidence to the discussion on the appropriate instrument base for pollution control, proving that nonpoint pollution control instruments cannot be assessed accurately without a correct understanding of the key underlying biophysical processes. Nonpoint pollution is characterized by nonlinearities, dynamics, and spatial dependency, and neglect of the dynamic aspects may lead to serious consequences for the design of measures. Finally, a quantitative assessment has been performed to explore discriminating measures based on crop pollution potential on vulnerable soils. No significant welfare gains are found from discriminating control, although results are contingent upon the level of damage, and discrimination could be justified in areas with valuable ecosystems and severe pollution damages.

Microbial Community Composition and Putative Biogeochemical Functions in the Sediment and Water of Tropical Granite Quarry Lakes.

PubMed

Kumar, Amit; Ng, Daphne H P; Wu, Yichao; Cao, Bin

2018-05-28

Re-naturalized quarry lakes are important ecosystems, which support complex communities of flora and fauna. Microorganisms associated with sediment and water form the lowest trophic level in these ecosystems and drive biogeochemical cycles. A direct comparison of microbial taxa in water and sediment microbial communities is lacking, which limits our understanding of the dominant functions that are carried out by the water and sediment microbial communities in quarry lakes. In this study, using the 16S rDNA amplicon sequencing approach, we compared microbial communities in the water and sediment in two re-naturalized quarry lakes in Singapore and elucidated putative functions of the sediment and water microbial communities in driving major biogeochemical processes. The richness and diversity of microbial communities in sediments of the quarry lakes were higher than those in the water. The composition of the microbial communities in the sediments from the two quarries was highly similar to one another, while those in the water differed greatly. Although the microbial communities of the sediment and water samples shared some common members, a large number of microbial taxa (at the phylum and genus levels) were prevalent either in sediment or water alone. Our results provide valuable insights into the prevalent biogeochemical processes carried out by water and sediment microbial communities in tropical granite quarry lakes, highlighting distinct microbial processes in water and sediment that contribute to the natural purification of the resident water.

Characterization of Florida red tide aerosol and the temporal profile of aerosol concentration.

PubMed

Cheng, Yung Sung; Zhou, Yue; Pierce, Richard H; Henry, Mike; Baden, Daniel G

2010-05-01

Red tide aerosols containing aerosolized brevetoxins are produced during the red tide bloom and transported by wind to coastal areas of Florida. This study reports the characterization of Florida red tide aerosols in human volunteer studies, in which an asthma cohort spent 1h on Siesta Beach (Sarasota, Florida) during aerosolized red tide events and non-exposure periods. Aerosol concentrations, brevetoxin levels, and particle size distribution were measured. Hourly filter samples were taken and analyzed for brevetoxin and NaCl concentrations. In addition, the aerosol mass concentration was monitored in real time. The results indicated that during a non-exposure period in October 2004, no brevetoxin was detected in the water, resulting in non-detectable levels of brevetoxin in the aerosol. In March 2005, the time-averaged concentrations of brevetoxins in water samples were moderate, in the range of 5-10 microg/L, and the corresponding brevetoxin level of Florida red tide aerosol ranged between 21 and 39 ng/m(3). The temporal profiles of red tide aerosol concentration in terms of mass, NaCl, and brevetoxin were in good agreement, indicating that NaCl and brevetoxins are components of the red tide aerosol. By continuously monitoring the marine aerosol and wind direction at Siesta Beach, we observed that the marine aerosol concentration varied as the wind direction changed. The temporal profile of the Florida red tide aerosol during a sampling period could be explained generally with the variation of wind direction. Copyright 2009 Elsevier Ltd. All rights reserved.

Water resources data for California, water year 1975; Volume 1: Colorado River basin, southern Great Basin from Mexican border to Mono Lake basin, and Pacific Slope basins from Tijuana River to Santa Maria River

USGS Publications Warehouse

,

1977-01-01

Water-resources data for the 1975 water year for California consist of records of streamflow and contents of reservoirs at gaging stations, partial-record stations, and miscellaneous sites; records of water quality including the physical, chemical, and biological characteristics of surface and ground water; and records of water levels in selected observation wells. Records for a few pertinent streamflow and water-quality stations in bordering States are also included. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey under the direction of Lee R. Peterson, district chief; Winchell Smith, assistant district chief for hydrologic data; and Leonard N. Jorgensen, chief of the basic data section. These data represent that part of the National Water Data System collected by the Geological Survey and cooperating local, State, and Federal agencies in California.

Stir bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry: an effective tool for determining persistent organic pollutants and nonylphenol in coastal waters in compliance with existing Directives.

PubMed

Sánchez-Avila, Juan; Quintana, Jordi; Ventura, Francesc; Tauler, Romà; Duarte, Carlos M; Lacorte, Silvia

2010-01-01

A multi-residual method based on stir bar sorptive extraction coupled with thermal desorption-gas chromatography-mass spectrometry (SBSE-TD-GC-MS) has been developed to measure 49 organic pollutants (organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers and nonylphenol) in seawater. Using 100ml of water, the method exhibited good linearity, with recoveries between 86% and 118% and relative standard deviation between 2% and 24% for almost all compounds. The method was applied to determine target contaminants in Catalonian seawater, including coastal areas, ports and desalination plant feed water. Overall individual compound levels oscillated between 0.16 and 597 ng l(-1); PAHs and nonylpenol were the compounds found at the highest concentrations. The method provided LODs between 0.011 and 2.5 ng l(-1), lower than the Environmental Quality Standards (EQS) fixed by Directive 2008/105/EC. In compliance with the directive, this method can be used as a tool to survey target compounds and is aimed at protecting coastal ecosystems from chemical pollution. Copyright 2009 Elsevier Ltd. All rights reserved.

Cyto- and genotoxic profile of groundwater used as drinking water supply before and after disinfection.

PubMed

Pellacani, C; Cassoni, F; Bocchi, C; Martino, A; Pinto, G; Fontana, F; Furlini, M; Buschini, A

2016-12-01

The assessment of the toxicological properties of raw groundwater may be useful to predict the type and quality of tap water. Contaminants in groundwater are known to be able to affect the disinfection process, resulting in the formation of substances that are cytotoxic and/or genotoxic. Though the European directive (98/83/EC, which establishes maximum levels for contaminants in raw water (RW)) provides threshold levels for acute exposure to toxic compounds, the law does not take into account chronic exposure at low doses of pollutants present in complex mixture. The purpose of this study was to evaluate the cyto- and genotoxic load in the groundwater of two water treatment plants in Northern Italy. Water samples induced cytotoxic effects, mainly observed when human cells were treated with RW. Moreover, results indicated that the disinfection process reduced cell toxicity, independent of the biocidal used. The induction of genotoxic effects was found, in particular, when the micronucleus assay was carried out on raw groundwater. These results suggest that it is important to include bio-toxicological assays as additional parameters in water quality monitoring programs, as their use would allow the evaluation of the potential risk of groundwater for humans.

Use of a macroinvertebrate based biotic index to estimate critical metal concentrations for good ecological water quality.

PubMed

Van Ael, Evy; De Cooman, Ward; Blust, Ronny; Bervoets, Lieven

2015-01-01

Large datasets from total and dissolved metal concentrations in Flemish (Belgium) fresh water systems and the associated macroinvertebrate-based biotic index MMIF (Multimetric Macroinvertebrate Index Flanders) were used to estimate critical metal concentrations for good ecological water quality, as imposed by the European Water Framework Directive (2000). The contribution of different stressors (metals and water characteristics) to the MMIF were studied by constructing generalized linear mixed effect models. Comparison between estimated critical concentrations and the European and Flemish EQS, shows that the EQS for As, Cd, Cu and Zn seem to be sufficient to reach a good ecological quality status as expressed by the invertebrate-based biotic index. In contrast, the EQS for Cr, Hg and Pb are higher than the estimated critical concentrations, which suggests that when environmental concentrations are at the same level as the EQS a good quality status might not be reached. The construction of mixed models that included metal concentrations in their structure did not lead to a significant outcome. However, mixed models showed the primary importance of water characteristics (oxygen level, temperature, ammonium concentration and conductivity) for the MMIF. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

1994-01-01

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 climate change; and presents the results of sensitivity analyses of how climate change might affect water resources in the Delaware River basin. Sensitivity analyses suggest that potentially serious shortfalls of certain water resources in the basin could result if some scenarios for climate change come true . The results of model simulations of the basin streamflow demonstrate the difficulty in distinguishing the effects that climate change versus natural climate variability have on streamflow and water supply . The future direction of basin changes in most water resources, furthermore, cannot be precisely determined 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 for evaluating and responding to changes, should they occur.

Water-resources activities in New York, 1987-88

USGS Publications Warehouse

Marshall, Mary P.; Finch, Anne J.

1988-01-01

The U.S. Geological Survey conducted more than 35 water resources projects in New York in 1987-88. These studies, done largely through cooperative joint-funding programs with the state, County, and local agencies, encompass statewide networks of measurement stations that provide continuous records of streamflow, groundwater levels, and water quality; they also address regional and local problems as well as critical problems of national scope. Some of the questions addressed by these studies are the effect of sewers on groundwater levels and streamflow on Long Island; the occurrence and transport of PCB residues within the upper Hudson River basin; the effect of acid rain on streams in the Catskill Mountains; the frequency and magnitude of floods statewide; the role of wetlands in improving the chemical quality of landfill leachate; the direction of groundwater movement from waste disposal sites near the Niagara River; and the location and potential well yields of stratified-drift aquifers in upstate New York. (USGS)

Surface-enhanced Raman as a water monitor for warfare agents

NASA Astrophysics Data System (ADS)

Spencer, Kevin M.; Sylvia, James M.; Clauson, Susan L.; Janni, James A.

2002-02-01

The threat of chemical warfare agents being released upon civilian and military personnel continues to escalate. One aspect of chemical preparedness is to analyze and protect the portable water supply for the military. Chemical nerve, blister, and choking agents, as well as biological threats must all be analyzed and low limits of detection must be verified. For chemical agents, this generally means detection down to the low ppb levels. Surface-Enhanced Raman Spectroscopy (SERS) is a spectroscopic technique that can detect trace levels of contaminants directly in the aqueous environment. In this paper, results are presented on the use of SERS to detect chemical and biological agent simulants with an end goal of creating a Joint Service Agent Water Monitor. Detection of cyanide, 2-chloroethyl ethyl sulfide, phosphonates, Gram-positive and Gram-negative bacteria using SERS has been performed and is discussed herein. Aspects of transferring laboratory results to an unattended field instrument are also discussed.

The Reaction of Criegee Intermediate CH 2OO with Water Dimer: Primary Products and Atmospheric Impact

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

Sheps, Leonid; Rotavera, Brandon; Eskola, Arkke J.

The rapid reaction of the smallest Criegee intermediate, CH 2OO, with water dimers is the dominant removal mechanism for CH 2OO in the Earth's atmosphere, but its products are not well understood. This reaction was recently suggested as a significant source of the most abundant tropospheric organic acid, formic acid (HCOOH), which is consistently underpredicted by atmospheric models. Furthermore, using time-resolved measurements of reaction kinetics by UV absorption and product analysis by photoionization mass spectrometry, we show that the primary products of this reaction are formaldehyde and hydroxymethyl hydroperoxide (HMHP), with direct HCOOH yields of less than 10%. Incorporating ourmore » results into a global chemistry-transport model further reduces HCOOH levels by 10–90%, relative to previous modeling assumptions, which indicates that the reaction CH 2OO + water dimer by itself cannot resolve the discrepancy between the measured and predicted HCOOH levels.« less

The Reaction of Criegee Intermediate CH 2OO with Water Dimer: Primary Products and Atmospheric Impact

DOE PAGES

Sheps, Leonid; Rotavera, Brandon; Eskola, Arkke J.; ...

2017-08-04

The rapid reaction of the smallest Criegee intermediate, CH 2OO, with water dimers is the dominant removal mechanism for CH 2OO in the Earth's atmosphere, but its products are not well understood. This reaction was recently suggested as a significant source of the most abundant tropospheric organic acid, formic acid (HCOOH), which is consistently underpredicted by atmospheric models. Furthermore, using time-resolved measurements of reaction kinetics by UV absorption and product analysis by photoionization mass spectrometry, we show that the primary products of this reaction are formaldehyde and hydroxymethyl hydroperoxide (HMHP), with direct HCOOH yields of less than 10%. Incorporating ourmore » results into a global chemistry-transport model further reduces HCOOH levels by 10–90%, relative to previous modeling assumptions, which indicates that the reaction CH 2OO + water dimer by itself cannot resolve the discrepancy between the measured and predicted HCOOH levels.« less

Improving water, sanitation and hygiene in health-care facilities, Liberia.

PubMed

Abrampah, Nana Mensah; Montgomery, Maggie; Baller, April; Ndivo, Francis; Gasasira, Alex; Cooper, Catherine; Frescas, Ruben; Gordon, Bruce; Syed, Shamsuzzoha Babar

2017-07-01

The lack of proper water and sanitation infrastructures and poor hygiene practices in health-care facilities reduces facilities' preparedness and response to disease outbreaks and decreases the communities' trust in the health services provided. To improve water and sanitation infrastructures and hygiene practices, the Liberian health ministry held multistakeholder meetings to develop a national water, sanitation and hygiene and environmental health package. A national train-the-trainer course was held for county environmental health technicians, which included infection prevention and control focal persons; the focal persons acted as change agents. In Liberia, only 45% of 701 surveyed health-care facilities had an improved water source in 2015, and only 27% of these health-care facilities had proper disposal for infectious waste. Local ownership, through engagement of local health workers, was introduced to ensure development and refinement of the package. In-county collaborations between health-care facilities, along with multisectoral collaboration, informed national level direction, which led to increased focus on water and sanitation infrastructures and uptake of hygiene practices to improve the overall quality of service delivery. National level leadership was important to identify a vision and create an enabling environment for changing the perception of water, sanitation and hygiene in health-care provision. The involvement of health workers was central to address basic infrastructure and hygiene practices in health-care facilities and they also worked as stimulators for sustainable change. Further, developing a long-term implementation plan for national level initiatives is important to ensure sustainability.

Water Levels and Selected Water-Quality Conditions in the Sparta-Memphis Aquifer (Middle Claiborne Aquifer) in Arkansas, Spring-Summer 2007

USGS Publications Warehouse

Schrader, T.P.

2009-01-01

The U.S. Geological Survey in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey has monitored water levels in the Sparta Sand of Claiborne Group and Memphis Sand of Claiborne Group (herein referred to as the Sparta Sand and the Memphis Sand, respectively), since the 1920s. Groundwater withdrawals have increased while water levels have declined since monitoring was initiated. Herein, aquifers in the Sparta Sand and Memphis Sand will be referred to as the Sparta-Memphis aquifer throughout Arkansas. During the spring of 2007, 309 water levels were measured in wells completed in the Sparta-Memphis aquifer. During the summer of 2007, 129 water-quality samples were collected and measured for temperature and specific conductance and 102 were collected and analyzed for chloride from wells completed in the Sparta-Memphis aquifer. Water-level measurements collected in wells screened in the Sparta-Memphis aquifer were used to produce a regional potentiometric-surface map. The regional direction of groundwater flow in the Sparta-Memphis aquifer is generally to the south-southeast in the northern half of Arkansas and to the east and south in the southern half of Arkansas, away from the outcrop area except where affected by large ground-water withdrawals. The highest water-level altitude measured in the Sparta-Memphis aquifer was 326 feet above National Geodetic Vertical Datum of 1929, located in Grant County in the outcrop at the western boundary of the study area; the lowest water-level altitude was 161 feet below National Geodetic Vertical Datum of 1929 in Union County near the southern boundary of the study area. Eight cones of depression (generally represented by closed contours) are located in the following counties: Bradley, Drew, and Ashley; Calhoun; Cleveland; Columbia; Crittenden; Arkansas, Jefferson, and Lincoln; Cross and Poinsett; and Union. Two large depressions are shown on the 2007 potentiometric-surface map, centered in Jefferson and Union Counties, as a result of large withdrawals for industrial and public supplies. The depression centered in Jefferson County deepened and expanded in recent years into Arkansas and Prairie Counties as a result of large withdrawals for irrigation and public supply. The area enclosed within the 40-foot contour has expanded on the 2007 potentiometric-surface map when compared with the 2005 potentiometric-surface map. In 2003, the depression in Union County was elongated east and west and beginning to coalesce with the depression in Columbia County. The deepest measurement during 2007 in the center of the depression in Union County has risen 38 feet since 2003. The area enclosed by the deepest contour, 160 feet below National Geodetic Vertical Datum of 1929, on the 2007 potentiometric-surface map is less than 10 percent of the area on the 2005 potentiometric-surface map. A broad depression in western Poinsett and Cross Counties was first shown in the 1995 potentiometric-surface map caused by withdrawals for irrigation extending north to the Poinsett-Craighead County line, and south into Cross County. A water-level difference map was constructed using the difference between water-level measurements made during 2003 and 2007 from 283 wells. The difference in water level between 2003 and 2007 ranged from -49.8 to 60.0 feet. Areas with a general rise in water levels are shown in northern Arkansas, Columbia, southern Jefferson, and most of Union Counties. In the area around west-central Union County, water levels rose as much as 60.0 feet with water levels in 15 wells rising 20 feet or more, which is an average annual rise of 5 feet or more. Water levels generally declined throughout most of the rest of Arkansas. Hydrographs from 157 wells were constructed with a minimum of 25 years of water-level measurements. During the period 1983-2007, the county mean annual water level rose in Calhoun, Columbia, Hot Spring, and Lafayette Counties. Mean an

Analysis of water-level fluctuations of Lakes Winona and Winnemissett-- two landlocked lakes in a karst terrane in Volusia County, Florida

USGS Publications Warehouse

Hughes, G.H.

1979-01-01

The water levels of Lakes Winona and Winnemissett in Volusia County, Fla., correlate reasonably well during dry spells but only poorly during wet spells. Disparities develop mostly at times when the lake levels rise abruptly owing to rainstorms passing over the lake basins. The lack of correlation is attributed to the uneven distribution of the storm rainfall, even though the average annual rainfall at National Weather Service gages in the general area of the lakes is about the same. Analyses of the monthly rainfall data show that the rainfall variability between gages is sufficient to account for most of the disparity between monthly changes in the levels of the two lakes. The total annual rainfall at times may differ between rainfall gages by as much as 15 to 20 inches. Such differences tend to balance over the long term but may persist in the same direction for two or more years, causing apparent anomalies in lake-level fluctuations. (Woodard-USGS)

Hydrology of the Wolf Branch sinkhole basin, Lake County, east-central Florida

USGS Publications Warehouse

Schiffer, D.M.

1996-01-01

A 4-year study of the hydrology of the Wolf Branch sinkhole basin in Lake County, Florida, was conducted from 1991-95 by the U.S. Geological Survey to provide information about the hydrologic characteristics of the drainage basin in the vicinity of Wolf Sink. Wolf Branch drains a 4.94 square mile area and directly recharges the Upper Floridan aquifer through Wolf Sink. Because of the direct connection of the sinkhole with the aquifer, a contaminant spill in the basin could pose a threat to the aquifer. The Wolf Branch drainage basin varies in hydrologic characteristics from its headwaters to its terminus at Wolf Sink. Ground- water seepage provides baseflow to the stream north of Wolf Branch Road, but the stream south of State Road 46 is intermittent and the stream can remain dry for months. A single culvert under a railroad crossing conducts flow from wetlands just south of State Road 46 to a well-defined channel which leads to Wolf Sink. The basin morphology is characterized by karst terrain, with many closed depressions which can provide intermittent surface-water storage. Wetlands in the lower third of the basin (south of State Road 46) also provide surface water storage. The presence of numerous water-control structures (impoundments, canals, and culverts), and the surface-water storage capacity throughout the basin affects the flow characteristics of Wolf Branch. Streamflow records for two stations (one above and one below major wetlands in the basin) indicate the flow about State Road 46 is characterized by rapid runoff and continuous baseflow, whereas below State Road 46, peak discharges are much lower but of longer duration than at the upstream station. Rainfall, discharge, ground-water level, and surface-water level data were collected at selected sites in the basin. Hydrologic conditions during the study ranged from long dry periods when there was no inflow to Wolf Sink, to very wet periods, as when nearly 7 inches of rain fell in a 2-day period in November 1994, following an extended wet season. A comparison to long-term rainfall record (40 years) indicates that this range in hydrologic conditions during the 4-year study is representative of the range of conditions expected during a much longer time period. Two dye-trace studies conducted during the study indicated no direct connections between the sink and local wells. The path of a constituent entering the aquifer through Wolf Sink generally would be to the east, following the gradient of the regional ground-water flow system. The conductance of Wolf Sink (the rate at which the sink conducts water to the underlying aquifer) was estimated from streamflow data, ground-water levels, and water levels in Wolf Sink. The range of hydrologic conditions during the study provided a basis for the determination of a representative conductance value. The regression of streamflow as a function of head difference between the sink water level and the potentiometric surface at an observation well (an approximation of the potentiometric level beneath Wolf Sink) resulted in a significant relation r2=0.91, mean square error = 1.60 cubic feet per second); and the slope of the regression line, representing sink conductance, was 1.48 cubic feet per second per foot of head difference. Flow and storm-volume frequency curves for selected time periods (1-day, 7-days, 14-days, 21-days, and 30-days) were generated based on streamflow data from January 10, 1992, to September 30, 1995. These curves indicate that, based on the available record, the volume of water that would have to be stored (in the event that streamflow had to be diverted from Wolf Sink) during a 30-day period would be equal to or less than about 11 acre-fee 30 percent of the time and 161 acre-feet 80 percent of the time. The maximum volume that would be generated during a 30-day period, based on this study, would be about 570 acre-feet.

Water levels in the aquifers of the Nacatoch Sand of southwestern and northeastern Arkansas and the Tokio Formation of southwestern Arkansas, February–March 2011

USGS Publications Warehouse

Schrader, T.P.; Rodgers, Kirk D.

2013-01-01

The aquifers in the Nacatoch Sand and Tokio Formation in southwestern Arkansas and the Nacatoch Sand in northeastern Arkansas are sources of water for industrial, public supply, domestic, and agricultural uses. Potentiometric-surface maps were constructed from water-level measurements made in 47 wells completed in the Nacatoch Sand and 45 wells completed in the Tokio Formation during February and March 2011. Aquifers in the Nacatoch Sand and Tokio Formation are hereafter referred to as the Nacatoch aquifer and the Tokio aquifer, respectively. The direction of groundwater flow in the Nacatoch aquifer in southwestern Arkansas is towards the southeast in Hempstead, Little River, and Miller Counties and east-southeast in Clark and Nevada Counties. A potentiometric high is located within the outcrop area of north-central Hempstead County. Two cones of depression exist in the Nacatoch aquifer, one at Hope in southeastern Hempstead County and one in Clark County. The direction of groundwater flow in the Nacatoch aquifer in northeastern Arkansas generally is towards the southeast. A potentiometric high in the study area is located along the north and northwestern boundaries of the area, but water levels may be higher outside the study area. In northeastern Arkansas, groundwater withdrawals from the Nacatoch aquifer increased by 564 percent from 1965 to 2010. In southwestern Arkansas, groundwater withdrawals from the Nacatoch Sand increased by 125 percent from 1965 to 1980, and withdrawals decreased by 85 percent from 1980 to 2010. In southwestern Arkansas, groundwater withdrawals from the Tokio aquifer increased by 201 percent from 1965 to 1980, and withdrawals decreased by 81 percent from 1980 to 2000. Withdrawals from the Tokio aquifer increased by 291 percent from 2000 to 2005, and withdrawals decreased by 32 percent from 2005 to 2010. The direction of groundwater flow in the Tokio aquifer in southwestern Arkansas generally is towards the south or southeast. The potentiometric high is within the outcrop area in the northern part of the area. Artesian flow exists or is inferred in southeastern Pike, northeastern Hempstead, and northwestern Nevada Counties. One apparent cone of depression might exist northwest of Hope in Hempstead County.

Use of a two-dimensional hydrodynamic model to evaluate extreme flooding and transport of dissolved solids through Devils Lake and Stump Lake, North Dakota, 2006

USGS Publications Warehouse

Nustad, Rochelle A.; Wood, Tamara M.; Bales, Jerad D.

2011-01-01

The U.S. Geological Survey in cooperation with the North Dakota Department of Transportation, North Dakota State Water Commission, and U.S. Army Corps of Engineers, developed a two-dimensional hydrodynamic model of Devils Lake and Stump Lake, North Dakota to be used as a hydrologic tool for evaluating the effects of different inflow scenarios on water levels, circulation, and the transport of dissolved solids through the lake. The numerical model, UnTRIM, and data primarily collected during 2006 were used to develop and calibrate the Devils Lake model. Performance of the Devils Lake model was tested using 2009 data. The Devils Lake model was applied to evaluate the effects of an extreme flooding event on water levels and hydrological modifications within the lake on the transport of dissolved solids through Devils Lake and Stump Lake. For the 2006 calibration, simulated water levels in Devils Lake compared well with measured water levels. The maximum simulated water level at site 1 was within 0.13 feet of the maximum measured water level in the calibration, which gives reasonable confidence that the Devils Lake model is able to accurately simulate the maximum water level at site 1 for the extreme flooding scenario. The timing and direction of winddriven fluctuations in water levels on a short time scale (a few hours to a day) were reproduced well by the Devils Lake model. For this application, the Devils Lake model was not optimized for simulation of the current speed through bridge openings. In future applications, simulation of current speed through bridge openings could be improved by more accurate definition of the bathymetry and geometry of select areas in the model grid. As a test of the performance of the Devils Lake model, a simulation of 2009 conditions from April 1 through September 30, 2009 was performed. Overall, errors in inflow estimates affected the results for the 2009 simulation; however, for the rising phase of the lakes, the Devils Lake model accurately simulated the faster rate of rise in Devils Lake than in Stump Lake, and timing and direction of wind-driven fluctuations in water levels on a short time scale were reproduced well. To help the U.S. Army Corps of Engineers determine the elevation to which the protective embankment for the city of Devils Lake should be raised, an extreme flooding scenario based on an inflow of one-half the probable maximum flood was simulated. Under the conditions and assumptions of the extreme flooding scenario, the water level for both lakes reached a maximum water level around 1,461.9 feet above the National Geodetic Vertical Datum of 1929. One factor limiting the extent of pumping from the Devils Lake State Outlet is sulfate concentrations in West Bay. If sulfate concentrations can be reduced in West Bay, pumping from the Devils Lake State Outlet potentially can increase. The Devils Lake model was used to simulate the transport of dissolved solids using specific conductance data as a surrogate for sulfate. Because the transport of dissolved solids was not calibrated, results from the simulations were not actual expected concentrations. However, the effects of hydrological modifications on the transport of dissolved solids could be evaluated by comparing the effects of hydrological modifications relative to a baseline scenario in which no hydrological modifications were made. Four scenarios were simulated: (1) baseline condition (no hydrological modification), (2) diversion of Channel A, (3) reduction of the area of water exchange between Main Bay and East Bay, and (4) combination of scenarios 2 and 3. Relative to scenario 1, mean concentrations in West Bay for scenarios 2 and 4 were reduced by approximately 9 percent. Given that there is no change in concentration for scenario 3, but about a 9-percent reduction in concentration for scenario 4, the diversion of Channel A was the only hydrologic modification that appeared to have the potential to reduce sulfate c

Exposure to low-dose barium by drinking water causes hearing loss in mice.

PubMed

Ohgami, Nobutaka; Hori, Sohjiro; Ohgami, Kyoko; Tamura, Haruka; Tsuzuki, Toyonori; Ohnuma, Shoko; Kato, Masashi

2012-10-01

We continuously ingest barium as a general element by drinking water and foods in our daily life. Exposure to high-dose barium (>100mg/kg/day) has been shown to cause physiological impairments. Direct administration of barium to inner ears by vascular perfusion has been shown to cause physiological impairments in inner ears. However, the toxic influence of oral exposure to low-dose barium on hearing levels has not been clarified in vivo. We analyzed the toxic influence of oral exposure to low-dose barium on hearing levels and inner ears in mice. We orally administered barium at low doses of 0.14 and 1.4 mg/kg/day to wild-type ICR mice by drinking water. The doses are equivalent to and 10-fold higher than the limit level (0.7 mg/l) of WHO health-based guidelines for drinking water, respectively. After 2-week exposure, hearing levels were measured by auditory brain stem responses and inner ears were morphologically analyzed. After 2-month exposure, tissue distribution of barium was measured by inductively coupled plasma mass spectrometry. Low-dose barium in drinking water caused severe hearing loss in mice. Inner ears including inner and outer hair cells, stria vascularis and spiral ganglion neurons showed severe degeneration. The Barium-administered group showed significantly higher levels of barium in inner ears than those in the control group, while barium levels in bone did not show a significant difference between the two groups. Barium levels in other tissues including the cerebrum, cerebellum, heart, liver and kidney were undetectably low in both groups. Our results demonstrate for the first time that low-dose barium administered by drinking water specifically distributes to inner ears resulting in severe ototoxicity with degeneration of inner ears in mice. Copyright © 2012 Elsevier Inc. All rights reserved.

Hydrogeological investigation at Site 5, Willow Grove Naval Air Station/Joint Reserve Base, Horsham Township, Montgomery County, Pennsylvania

USGS Publications Warehouse

Sloto, Ronald A.

2002-01-01

The U.S. Geological Survey conducted borehole geophysical logging, collected and analyzed water-level data, and sampled sections of a rock core to determine the concentration of volatile organic compounds in the aquifer matrix of the Stockton Formation. Borehole geophysical logs were run in three monitor wells. At well 05MW04I, the vertical gradient was upward at depths above 42 feet below land surface (ft bls), downward between 42 and 82 ft bls, and upward below 82 ft bls. At well 05MW05I, a downward vertical gradient was present. At well 05MW12I, the vertical gradient was downward above 112 ft bls and upward below 112 ft bls.Three water-bearing fractures in a 17-foot long rock core from 23.5 to 40.5 ft bls were identified and sampled. Three samples were analyzed from each water-bearing fracture—at the fracture face, 2 centimeters (cm) below the fracture, and 4 cm below the fracture. Fifteen compounds were detected; however, concentrations of seven compounds were less than 1 microgram per kilogram (mg/kg) when detected. Concentrations of benzene (from 0.39 to 3.3 mg/kg), 1,1-dichloroethene (1,1-DCE) (from 0.15 to 13 mg/kg), 1,1,1-trichloroethane (TCA) (from 0.17 to 22 mg/kg), and trichloroethylene (TCE) (from 0.092 to 9.6 mg/kg) were detected in all samples. The highest concentrations detected were for toluene, which was detected at a concentration of 32 and 86 mg/kg in the samples from unweathered sandstone at 2 and 4 cm below the fracture, respectively. Concentrations generally decreased with distance below the fracture in the mudstone samples. Concentrations of benzene and toluene increased with distance below the fractures in the unweathered sandstone samples. Concentrations of 1,1-DCE, TCA, and TCE were higher in the mudstone samples than in the samples from sandstone. Toluene concentrations were higher in unweathered sandstone than in weathered sandstone or mudstone.The effect of the pumping of Horsham Water and Sewer Authority public supply well 26 (HWSA-26), 0.2 mile southwest of the base boundary, on groundwater levels on the base was determined by shutting the well down for 6 days to allow water levels to recover. Water levels in 22 nearby wells were measured. The only well (02MW01I) that showed an unambiguous response to the shutdown of well HWSA-26 is 1,350 feet directly along strike from well HWSA-26. The recovery of well 05MW11I in response to the shutdown of well HWSA-26 is masked by recharge from snowmelt but probably does not exceed about 0.2 feet on the basis of the water level in well 05MW11I, which showed a response to the pumping of well HWSA-26 that ranged from 0.5 to 0.15 foot.Horizontal gradients differ with depth, and the rate and direction of ground-water flow and contaminant movement is depth dependent. The potentiometric-surface map for water levels measured in wells screened between 5 and 44 ft bls in the aquifer shows a ground-water mound that is the high point on a regional ground-water divide. From this divide, ground water flows both northwest toward Park Creek and southeast toward Pennypack Creek. The hydraulic gradient around this mound is relatively flat to the southeast and particularly flat to the northwest. The potentiometric-surface map for water levels measured in wells screened between 40 and 100 ft bls in the aquifer shows a very flat hydraulic gradient. Differences in the elevation of the potentiometric surface are less than 2 feet. The potentiometric-surface map for water levels measured in wells screened between 105 and 179 ft bls in the aquifer shows a steep hydraulic gradient between Sites 5 and 2 and a relatively flat hydraulic gradient between Sites 5 and 3. Water levels measured on October 7, 1999, showed downward vertical head gradients for all well clusters at Site 5. Vertical gradients ranged from 0.01 at well cluster 05MW10 to 0.2 at cluster 05MW11. Most gradients were between 0.01 and 0.026. Vertical head gradients vary with time. The variability is caused by a difference in the magnitude of water-level fluctuations between shallow and the deep fractures. The difference in the magnitude of water-level fluctuations is because of differences in lithology and aquifer storativity.

Optical transmission measurements for in-line monitoring of turbid oil-water emulsions

NASA Astrophysics Data System (ADS)

Metz, Philipp; Dopf, Katja; Aichholz, Markus; Riedel, Boris; Lemmer, Uli; Freudig, Barbara; Zimmermann, Clifton; Gerken, Martina

2014-05-01

For absorbing media the concentration may be calculated directly from the optical transmission following the logarithmic dependence given in the Lambert-Beer law. Due to multiple scattering events in oil-water emulsions (e.g. milk, cream, etc.), these exhibit a nonlinear relationship between the attenuation and the oil concentration. We demonstrate that for increasing oil content in oil-water emulsions the attenuation first increases, then levels out, and finally even decreases for a fat content of 60%. Single-wavelength optical transmission measurements are found to be well suited for the in-line monitoring of oil-water emulsions of fat contents below 20%, e.g., for the in-line fat content monitoring of milk. Using experiments and ray-tracing simulations we evaluate system optimization.

[Infections related to recreational waters].

PubMed

Doménech-Sánchez, Antonio; Olea, Francisco; Berrocal, Clara I

2008-11-01

Recreational waters are a source of infection by several microorganisms causing acute gastrointestinal, cutaneous and respiratory illnesses. Cryptosporidium, noroviruses and enteropathogenic Escherichia coli strains are the most important causes of diarrhea, while Pseudomonas and Staphylococcus aureus are the main causes of cutaneous infections, and Legionella is the major cause of acute lower respiratory disease. Approximately 90% of outbreaks occur in treated recreational waters (swimming pools, spas and recreational parks), while the remaining 10% arise from natural waters used for leisure (bathing in rivers, beaches, etc). In spas, most infections are caused by thermophilic bacteria, such as Pseudomonas and Legionella, since overgrowth of these bacteria is facilitated by the direct effect of temperature and, indirectly, by the evaporation of the disinfectant. Outbreaks related to recreational waters usually reflect deficient control of the system: a low level of disinfectant, or the use of an inappropriate disinfectant, insufficient maintenance and cleaning of the installation, higher than recommended usage, and failure of the disinfectant dosage system. The correct design, maintenance and use of these facilities drastically lower the risk of infections from recreational waters. Thus, other key actions to minimize this risk are the existence of, and compliance with, regulatory rules, as well as educational campaigns on good hygiene practices directed at users. Rapid etiologic diagnosis of affected patients, together with an epidemiological survey and detection of the pathogen implicated in water samples are the keys to outbreak control.

Moving from local to State water governance to resolve a local conflict between irrigated agriculture and commercial forestry in South Australia

NASA Astrophysics Data System (ADS)

Gillet, Virginie; McKay, Jennifer; Keremane, Ganesh

2014-11-01

In the Lower Limestone Coast, South Australia, a unique water allocation plan has been under consideration for several years. This plan is the first in Australia to consider forestry as a water affecting activity. Indeed, forestry plantations have a twofold impact on water-rainfall or aquifer recharge interception and direct extraction of groundwater in shallow water table areas-and alter the available water for irrigation as a result of the previous water budget. This paper examines how water is allocated across the competing requirements for water but also across the competing legal, economic and administrative scales embodied by the competing water users; and thus it also details the pre-judicial mechanism used to resolve the conflict over these competing scales. Qualitative and quantitative content analysis in Nvivo was applied to: (i) 180 local newspaper articles on the planning process, (ii) 65 submission forms filled in by the community during a public consultation on the draft water plan and (iii) 20 face-to-face interviews of keys stakeholders involved in the planning process. The social sustainability perspective taken in this study establishes the legal, economic and administrative competitive scales at stake in the conflict regarding water between forestry and irrigation. It also evidences the special feature of this paper, which is that to overcome these competitions and resolve the local conflict before judicial process, the water governance moved up in the administrative scale, from local/regional to State level. Initiated and initially prepared at regional level through the local Natural Resources Management Board, the water planning process was taken up to State level through the formation of an Interdepartmental Committee and the establishment of a Taskforce in charge of developing a policy. These were supported by an amendment of a State legislation on Natural Resources Management to manage the water impacts of forestry plantations.

A direct evaluation of the Geosat altimeter wet atmospheric range delay using very long baseline interferometry observations

NASA Technical Reports Server (NTRS)

Koblinsky, C. J.; Ryan, J.; Braatz, L.; Klosko, S. M.

1993-01-01

The overall accuracy of the U.S. Navy Geosat altimeter wet atmospheric range delay caused by refraction through the atmosphere is directly assessed by comparing the estimates made from the DMSP Special Sensor Microwave/Imager and the U.S. Navy Fleet Numerical Ocean Center forecast model for Geosat with measurements of total zenith columnar water vapor content from four VLBI sites. The assessment is made by comparing time series of range delay from various methods at each location. To determine the importance of diurnal variation in water vapor content in noncoincident estimates, the VLBI measurements were made at 15-min intervals over a few days. The VLBI measurements showed strong diurnal variations in columnar water vapor at several sites, causing errors of the order 3 cm rms in any noncoincident measurement of the wet troposphere range delay. These errors have an effect on studies of annual and interannual changes in sea level with Geosat data.

Earth-atmosphere system and surface reflectivities in arid regions from Landsat MSS data

NASA Technical Reports Server (NTRS)

Otterman, J.; Fraser, R. S.

1976-01-01

Previously developed programs for computing atmospheric transmission and scattering of the solar radiation are used to compute the ratios of the earth-atmosphere system (space) directional reflectivities in the nadir direction to the surface Lambertian reflectivity, for the four bands of the Landsat multispectral scanner (MSS). These ratios are presented as graphs for two water vapor levels, as a function of the surface reflectivity, for various sun elevation angles. Space directional reflectivities in the vertical direction are reported for selected arid regions in Asia, Africa, and Central America from the spectral radiance levels measured by the Landsat MSS. From these space reflectivities, surface reflectivities are computed applying the pertinent graphs. These surface reflectivities are used to estimate the surface albedo for the entire solar spectrum. The estimated albedos are in the range 0.34-0.52, higher than the values reported by most previous researchers from space measurements, but are consistent with laboratory and in situ measurements.

Anisotropy indices and the effects on the hydric behaviour of natural stone

NASA Astrophysics Data System (ADS)

Fort, Rafael; Alvarez de Buergo, Monica; Varas, Maria Jose; Gomez-Heras, Miguel

2010-05-01

Building stone is an anisotropic material. Each type of rock (granite, limestone, slate, marble, etc.) has a different anisotropy, which is related to its own geological history, i.e. formation conditions and alteration processes. Knowing the anisotropy of natural stone is a matter of interest for determining the most adequate way to extract it from the quarry, for a better use during its manufacture or processing, to determine the quality of elements to be used as ashlars/masonry or as ornamental elements carving, as well to their arrangement in a structure. At the same time, materiaĺs anisotropy will condition the placing of, for instance, anchorages in dressing stone slabs. Anisotropy of natural stone controls water entry and its mobility, together with atmospheric pollutantśs, processes that favour the stone decay in building works, mainly those that shows a marked directional component, as it is the case of capillary water absorption. Water tends to be absorbed differently along the distinct main anisotropy directions, which are principally marked due to the arrangement and distribution of porosity in the rock. The aim of this study is to perform a comparative analysis of the various anisotropy indices commonly used when dealing with natural stone, determined by ultrasonic propagation techniques, in order to establish how anisotropy (by means of these indices) affect the process of capillary water absorption. Different type of natural stones have been selected, according to their traditional use for the construction of buildings in the region of Madrid (Spain). Their petrophysical properties have been determined (density, porosity, water absorption, etc), as well as ultrasonic transmission velocity has been measured along the three spatial directions of the test specimens (from 50 to 100 for each petrological type). According to this, the stone specimens were classified in different anisotropy levels or classes. Results show that stones with the highest anisotropy are those with the highest capillarity coefficient. It can also be observed that for each petrological variety, this capillarity coefficient is higher in the specimens classified as a high level anisotropy class. At the same time, when capillary water is absorbed along the direction perpendicular to the anisotropic planes, the absorption capacity diminishes, no matter the anisotropy level of the stone is. On the contrary, capillary coefficients are higher when measurements are performed in a parallel direction to that of the greatest anisotropy of the stone specimen, where absorption tends to be faster with higher coefficients according to the porosity size and its geometry. These increments are more significant in the stone varieties in which anisotropy is mainly due to fissuring or schistosity planes, or related to stromatolitic planes or oriented minerals accumulation. The arrangement and placing of rocks used as building materials with a significant anisotropy will highly condition the durability and lifetime of a considered element. For that reason, is essential to determine anisotropy indices to obtain the best and most adequate arrangement of stone elements in building works, minimizing water entry and thus, the material decay. Acknowledgements: to both MATERNAS (0505/MAT/0094) and GEOMATERIALES (2009-1629) research programmes, funded by the Regional Government of Madrid; to the CONSOLIDER-INGENIO programme (CSD2007-0058), funded by the Spanish Ministry of Education and Science; and to the Spanish Geological and Mining Institute (IGME) for the specimens preparation and hydric behaviour measurements.

Estimating the Effect of School Water, Sanitation, and Hygiene Improvements on Pupil Health Outcomes.

PubMed

Garn, Joshua V; Brumback, Babette A; Drews-Botsch, Carolyn D; Lash, Timothy L; Kramer, Michael R; Freeman, Matthew C

2016-09-01

We conducted a cluster-randomized water, sanitation, and hygiene trial in 185 schools in Nyanza province, Kenya. The trial, however, had imperfect school-level adherence at many schools. The primary goal of this study was to estimate the causal effects of school-level adherence to interventions on pupil diarrhea and soil-transmitted helminth infection. Schools were divided into water availability groups, which were then randomized separately into either water, sanitation, and hygiene intervention arms or a control arm. School-level adherence to the intervention was defined by the number of intervention components-water, latrines, soap-that had been adequately implemented. The outcomes of interest were pupil diarrhea and soil-transmitted helminth infection. We used a weighted generalized structural nested model to calculate prevalence ratio. In the water-scarce group, there was evidence of a reduced prevalence of diarrhea among pupils attending schools that adhered to two or to three intervention components (prevalence ratio = 0.28, 95% confidence interval: 0.10, 0.75), compared with what the prevalence would have been had the same schools instead adhered to zero components or one. In the water-available group, there was no evidence of reduced diarrhea with better adherence. For the soil-transmitted helminth infection and intensity outcomes, we often observed point estimates in the preventive direction with increasing intervention adherence, but primarily among girls, and the confidence intervals were often very wide. Our instrumental variable point estimates sometimes suggested protective effects with increased water, sanitation, and hygiene intervention adherence, although many of the estimates were imprecise.

Analysis of haloacetic acids, bromate, and dalapon in natural waters by ion chromatography-tandem mass spectrometry.

PubMed

Wu, Shimin; Anumol, Tarun; Gandhi, Jay; Snyder, Shane A

2017-03-03

The addition of oxidants for disinfecting water can lead to the formation of potentially carcinogenic compounds referred to as disinfection byproducts (DBPs). Haloacetic acids (HAAs) are one of the most widely detected DBPs in US water utilities and some of them are regulated by the US Environmental Protection Agency (USEPA). The present study developed a method to analyze all the compounds in the USEPA method 557 (nine HAAs, bromate and dalapon) plus four potentially more toxic iodinated HAAs in water by coupling ion chromatography with tandem mass spectrometry (IC-MS/MS). This aqueous direct injection method has significant advantages over traditional GC methods, which require a derivatization and sample extraction that are laborious, time-consuming, and can negatively impact reproducibility. The method developed in this study requires half the time of the current USEPA method 557 on IC-MS/MS while including more compounds and achieving sub-μg/L level method detection limits (MDLs) for all 15 target analytes. The single laboratory lowest concentration minimum reporting level (LCMRL) has also been determined in reagent water, which ranged from 0.011 to 0.62μg/L for the analytes. The mean recoveries of the analytes during matrix spike recovery tests were 77-125% in finished drinking water and 81-112% in surface water. This method was then applied to untreated, chlorinated, and chloraminated groundwater and surface water samples. Bromate and 9 HAAs were detected at different levels in some of these samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of a separate tank with an electrolysis-dependent bacteria controlling system for the long term storage of potable water.

PubMed

Ishizuka, Akinori; Tanji, Masataka; Hayashi, Nobuatsu; Wakabayashi, Akihiro; Tatsumoto, Hideki; Hotta, Kunimoto

2006-12-01

For the long term storage of tap water, we developed a separate type of tank (5 m3) equipped with an electrolysis system to control bacterial growth. The electrolysis conditions using 20A direct current and a water flow rate of 10 L/min were capable of producing available chlorine (AC) at the rate of 5-8mg/min and raising the AC level of the stored tap water by about 0.2 mg/kg within 20-30 min The electrolyzed tap water with 0.2 mg/kg AC showed a capability per ml of killing 10(5)-10(6) cfu of bacteria such as Escherichia coli and Pseudomonas aeruginosa within 15 sec. A 6-month trial operation of the storage system with an automatic electrolysis control to keep AC level ranging 0.2-0.4 mg/kg demonstrated that the system worked well for the stored tap water in suppressing bacterial growth as well as in keeping good potable quality with reference to the 46 parameters specified for Japanese tap water. Actually, the electrolysis treatment was administered intermittently with an interval of about two weeks. Thus we believe the developed system has good potential to secure a potable water supply not only in the occasion of emergencies but also in countries having problems in the supply of safe drinking water.

Natural radioactivity in various water samples and radiation dose estimations in Bolu province, Turkey.

PubMed

Gorur, F Korkmaz; Camgoz, H

2014-10-01

The level of natural radioactivity for Bolu province of north-western Turkey was assessed in this study. There is no information about radioactivity measurement reported in water samples in the Bolu province so far. For this reason, gross α and β activities of 55 different water samples collected from tap, spring, mineral, river and lake waters in Bolu were determined. The mean activity concentrations were 68.11 mBq L(-1), 169.44 mBq L(-1) for gross α and β in tap water. For all samples the gross β activity is always higher than the gross α activity. All value of the gross α were lower than the limit value of 500 mBq L(-1) while two spring and one mineral water samples were found to have gross β activity concentrations of greater than 1000 mBq L(-1). The associated age-dependent dose from all water ingestion in Bolu was estimated. The total dose for adults had an average value exceeds the WHO recommended limit value. The risk levels from the direct ingestion of the natural radionuclides in tap and mineral water in Bolu were determinated. The mean (210)Po and (228)Ra risk the value of tap and mineral waters slightly exceeds what some consider on acceptable risk of 10(-4) or less. Copyright © 2014 Elsevier Ltd. All rights reserved.

The atmosphere can be a source of certain water soluble volatile organic compounds in urban streams

USGS Publications Warehouse

Kenner, Scott J.; Bender, David A.; Zogorski, John S.; ,; James F. Pankow,

2014-01-01

Surface water and air volatile organic compound (VOC) data from 10 U.S. Geological Survey monitoring sites were used to evaluate the potential for direct transport of VOCs from the atmosphere to urban streams. Analytical results of 87 VOC compounds were screened by evaluating the occurrence and detection levels in both water and air, and equilibrium concentrations in water (Cws) based on the measured air concentrations. Four compounds (acetone, methyl tertiary butyl ether, toluene, and m- & p-xylene) were detected in more than 20% of water samples, in more than 10% of air samples, and more than 10% of detections in air were greater than long-term method detection levels (LTMDL) in water. Benzene was detected in more than 20% of water samples and in more than 10% of air samples. Two percent of benzene detections in air were greater than one-half the LTMDL in water. Six compounds (chloroform, p-isopropyltoluene, methylene chloride, perchloroethene, 1,1,1-trichloroethane, and trichloroethene) were detected in more than 20% of water samples and in more than 10% of air samples. Five VOCs, toluene, m- & p-xylene, methyl tert-butyl ether (MTBE), acetone, and benzene were identified as having sufficiently high concentrations in the atmosphere to be a source to urban streams. MTBE, acetone, and benzene exhibited behavior that was consistent with equilibrium concentrations in the atmosphere.

Estimating the environmental and resource costs of leakage in water distribution systems: A shadow price approach.

PubMed

Molinos-Senante, María; Mocholí-Arce, Manuel; Sala-Garrido, Ramon

2016-10-15

Water scarcity is one of the main problems faced by many regions in the XXIst century. In this context, the need to reduce leakages from water distribution systems has gained almost universal acceptance. The concept of sustainable economic level of leakage (SELL) has been proposed to internalize the environmental and resource costs within economic level of leakage calculations. However, because these costs are not set by the market, they have not often been calculated. In this paper, the directional-distance function was used to estimate the shadow price of leakages as a proxy of their environmental and resource costs. This is a pioneering approach to the economic valuation of leakage externalities. An empirical application was carried out for the main Chilean water companies. The estimated results indicated that for 2014, the average shadow price of leakages was approximately 32% of the price of the water delivered. Moreover, as a sensitivity analysis, the shadow prices of the leakages were calculated from the perspective of the water companies' managers and the regulator. The methodology and findings of this study are essential for supporting the decision process of reducing leakage, contributing to the improvement of economic, social and environmental efficiency and sustainability of urban water supplies. Copyright © 2016 Elsevier B.V. All rights reserved.

Addressing the Sustainability of Groundwater Extraction in California Using Hydrochronology

NASA Astrophysics Data System (ADS)

Moran, J. E.; Visser, A.; Singleton, M. J.; Esser, B. K.

2017-12-01

In urban and agricultural settings in California, intense pressure on water supplies has led to extensive managed aquifer recharge and extensive overdraft in these areas, respectively. The California Sustainable Groundwater Management Act (SGMA) includes criteria for pumping that maintains groundwater levels and basin storage, and avoids stream depletion and degradation of water quality. Most sustainability plans will likely use water level monitoring and water budget balancing based on integrated flow models as evidence of compliance. However, hydrochronology data are applicable to several of the criteria, and provide an independent method of addressing questions related to basin turnover time, recharge rate, surface water-groundwater interaction, and the age distribution at pumping wells. We have applied hydrochronology (mainly tritium-helium groundwater age dating and extrinsic tracers) in urban areas to delineate flowpaths of artificially recharged water, to identify stagnant zones bypassed by the engineered flow system, and to predict vulnerability of drinking water sources to contamination. In agricultural areas, we have applied multi-tracer hydrochronology to delineate groundwater stratigraphy, to identify paleowater, and to project future nitrate concentrations in long-screened wells. This presentation will describe examples in which groundwater dating and other tracer methods can be applied to directly address the SGMA criteria for sustainable groundwater pumping.

Development of the oil-water monitor

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

Swanson, C.

1990-04-02

The oil-water monitor is a device invented by Dr. Claude Swanson of Applied Physics Technology to respond to the petroleum-loss problem in crude oil transfers. It is a device which measures water content in crude oil and other petroleum products, in a flowing pipe such as a pipeline or tanker manifold. It is capable of accurately measuring the water contamination levels in crude oil shipments, in real time as the crude oil flows through the loading manifold into the tanker, or at the receiving point as the oil is off-loaded It has application in the verification of oil volumes andmore » concentration of contaminants at petroleum transfer points. The industry-estimated level of water loss at transfer points due to inadequate monitoring technology amounts to several billion dollars per year, so there is a definite perceived need within the petroleum community for this type of accurate water monitoring technology. The device has been patented, and initial feasibility experiments have been conducted. The present research is directed toward developing and demonstrating a bench model prototype of the oil-water monitor, complete with the computer software and automated microwave equipment and electronics which will demonstrate the performance of the invention, for implementation in full-scale fielded systems. 3 figs.« less

Comparison of hyporheic flow and water quality in open and tree-covered banks downstream of Xin'an River dam, China

NASA Astrophysics Data System (ADS)

Liu, D.

2017-12-01

Plants, especially trees, in the riparian zone may have a significant impact on the flow rate, temperature and chemical properties of groundwater. A field study was conducted in the downstream bank of the Xin'an River dam, Zhejiang, China. In the field, two areas of about 20 meters apart were chosen, of which one was a open place and the other was covered with many orange trees. Comparison of hyporheic flow and water quality in the open and tree-covered banks were made by monitoring the water level, water temperature, water chemistry (March, 2015) along the cross sections perpendicular to the river. The analyses indicated that water level around the trees was relatively low in the day and high in the evening, thus changed the direction and magnitude of the natural groundwater flow velocity, totally strengthened the hyporheic exchange between the groundwater and river. The trees also changed the temperature distribution of the natural river bank, and induced the wider infiltration range of the low-temperature water. The temperature around the trees was relatively low in the day, yet it was high in the evening. Dissolved oxygen (DO) and electricity conductivity (EC) around the trees were significantly increased, yet the pH was almost unaffected.

Concepts and data-collection techniques used in a study of the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Illinois

USGS Publications Warehouse

Healy, R.W.; DeVries, M.P.; Striegl, Robert G.

1986-01-01

A study of water and radionuclide movement through the unsaturated zone is being conducted at the low level radioactive waste disposal site near Sheffield, Illinois. Included in the study are detailed investigations of evapotranspiration, movement of water through waste trench covers, and movement of water and radionuclides (dissolved and gaseous) from the trenches. An energy balance/Bowen ratio approach is used to determine evapotranspiration. Precipitation, net radiation, soil-heat flux, air temperature and water vapor content gradients, wind speed, and wind direction are measured. Soil water tension is measured with tensiometers which are connected to pressure transducers. Meteorological sensors and tensiometers which are connected to pressure transducers. Meteorological sensors and tensiometers are monitored with automatic data loggers. Soil moisture contents are measured through small-diameter access tubes with neutron and gamma-ray attenuation gages. Data beneath the trenches are obtained through a 130-meter-long tunnel which extends under four of the trenches. Water samples are obtained with suction lysimeters, and samples of the geologic material are obtained with core tubes. These samples are analyzed for radiometric and inorganic chemistry. Gas samples are obtained from gas piezometers and analyzed for partial pressures of major constituents, Radon-222, tritiated water vapor, and carbon-14 dioxide. (USGS)

Insights into the role of wettability in cathode catalyst layer of proton exchange membrane fuel cell; pore scale immiscible flow and transport processes

NASA Astrophysics Data System (ADS)

Fathi, H.; Raoof, A.; Mansouri, S. H.

2017-05-01

The production of liquid water in cathode catalyst layer, CCL, is a significant barrier to increase the efficiency of proton exchange membrane fuel cell. Here we present, for the first time, a direct three-dimensional pore-scale modelling to look at the complex immiscible two-phase flow in CCL. After production of the liquid water at the surface of CCL agglomerates due to the electrochemical reactions, water spatial distribution affects transport of oxygen through the CCL as well as the rate of reaction at the agglomerate surfaces. To explore the wettability effects, we apply hydrophilic and hydrophobic properties using different surface contact angles. Effective diffusivity is calculated under several water saturation levels. Results indicate larger diffusive transport values for hydrophilic domain compared to the hydrophobic media where the liquid water preferentially floods the larger pores. However, hydrophobic domain showed more available surface area and higher oxygen consumption rate at the reaction sites under various saturation levels, which is explained by the effect of wettability on pore-scale distribution of water. Hydrophobic domain, with a contact angle of 150, reveals efficient water removal where only 28% of the pore space stays saturated. This condition contributes to the enhanced available reaction surface area and oxygen diffusivity.

Litter type affects the activity of aerobic decomposers in a boreal peatland more than site nutrient and water level regimes

NASA Astrophysics Data System (ADS)

Straková, P.; Niemi, R. M.; Freeman, C.; Peltoniemi, K.; Toberman, H.; Heiskanen, I.; Fritze, H.; Laiho, R.

2011-02-01

Peatlands are carbon (C) storage ecosystems sustained by a high water level (WL). High WL creates anoxic conditions that suppress the activity of aerobic decomposers and provide conditions for peat accumulation. Peatland function can be dramatically affected by WL drawdown caused by land-use and/or climate change. Aerobic decomposers are directly affected by WL drawdown through environmental factors such as increased oxygenation and nutrient availability. Additionally, they are indirectly affected via changes in plant community composition and litter quality. We studied the relative importance of direct and indirect effects of WL drawdown on aerobic decomposer activity in plant litter. We did this by profiling 11 extracellular enzymes involved in the mineralization of organic C, nitrogen, phosphorus and sulphur. Our study sites represented a three-stage chronosequence from pristine (undrained) to short-term (years) and long-term (decades) WL drawdown conditions under two nutrient regimes. The litter types included reflected the prevalent vegetation, i.e., Sphagnum mosses, graminoids, shrubs and trees. WL drawdown had a direct and positive effect on microbial activity. Enzyme allocation shifted towards C acquisition, which caused an increase in the rate of decomposition. However, litter type overruled the direct effects of WL drawdown and was the main factor shaping microbial activity patterns. Our results imply that changes in plant community composition in response to persistent WL drawdown will strongly affect the C dynamics of peatlands.

Water Stress in Global Transboundary River Basins: Significance of Upstream Water Use on Downstream Stress

NASA Technical Reports Server (NTRS)

Munia, H.; Guillaume, J. H. A.; Mirumachi, N.; Porkka,M.; Wada, Yoshihide; Kummu, M.

2016-01-01

Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analyzed in many of these international river basins, this has not been systematically done at the global scale using coherent and comparable datasets. In this study, we aim to assess the change in downstream water stress due to upstream water use in the world's transboundary river basins. Water stress was first calculated considering only local water use of each sub-basin based on country-basin mesh, then compared with the situation when upstream water use was subtracted from downstream water availability. Wefound that water stress was generally already high when considering only local water use, affecting 0.95-1.44 billion people or 33%-51% of the population in transboundary river basins. After accounting for upstream water use, stress level increased by at least 1 percentage-point for 30-65 sub-basins, affecting 0.29-1.13 billion people. Altogether 288 out of 298 middle-stream and downstream sub-basin areas experienced some change in stress level. Further, we assessed whether there is a link between increased water stress due to upstream water use and the number of conflictive and cooperative events in the transboundary river basins, as captured by two prominent databases. No direct relationship was found. This supports the argument that conflicts and cooperation events originate from a combination of different drivers, among which upstream-induced water stress may play a role. Our findings contribute to better understanding of upstream-downstream dynamics in water stress to help address water allocation problems.

Ground-water resources in the lower Milliken--Sarco--Tulucay Creeks area, southeastern Napa County, California, 2000-2002

USGS Publications Warehouse

Farrar, Christopher D.; Metzger, Loren F.

2003-01-01

Ground water obtained from individual private wells is the sole source of water for about 4,800 residents living in the lower Milliken-Sarco-Tulucay Creeks area of southeastern Napa County. Increases in population and in irrigated vineyards during the past few decades have increased water demand. Estimated ground-water pumpage in 2000 was 5,350 acre-feet per year, an increase of about 80 percent since 1975. Water for agricultural irrigation is the dominant use, accounting for about 45 percent of the total. This increase in ground-water extraction has resulted in the general decline of ground-water levels. The purpose of this report is to present selected hydrologic data collected from 1975 to 2002 and to quantify changes in the ground-water system during the past 25 years. The study area lies in one of several prominent northwest-trending structural valleys in the North Coast Ranges. The area is underlain by alluvial deposits and volcanic rocks that exceed 1,000 feet in thickness in some places. Alluvial deposits and tuff beds in the volcanic sequence are the principal source of water to wells. The ground-water system is recharged by precipitation that infiltrates, in minor amounts, directly on the valley floor but mostly by infiltration in the Howell Mountains. Ground water moves laterally from the Howell Mountains into the study area. Although the area receives abundant winter precipitation in most years, nearly half of the precipitation is lost as surface runoff to the Napa River. Evapotranspiration also is high, accounting for nearly one-half of the total precipitation received. Because of the uncertainties in the estimates of precipitation, runoff, and evapotranspiration, a precise estimate of potential ground-water recharge cannot be made. Large changes in ground-water levels occurred between 1975 and 2001. In much of the western part of the area, water levels increased; but in the central and eastern parts, water levels declined by 25 to 125 feet. Ground-water extraction produced three large pumping depressions in the northern and east-central parts of the area. The general decline in ground-water levels is a result of increases in ground-water pumpage and possibly changes in infiltration capacity caused by changes in land use. Ground-water-level declines during 1960-2002 are evident in the records for 9 of 10 key monitoring wells. In five of these wells, water levels dropped by greater than 20 feet since the 1980s. The largest water-level declines have occurred since the mid 1970s, corresponding with a period of accelerated well construction and ground-water extraction. Analysis of samples from 15 wells indicates that the chemical quality of ground water in the study generally is acceptable. However, arsenic concentrations in samples from five wells exceed the U.S. Environmental Protection Agency primary drinking-water standard of 10 micrograms per liter, and iron concentrations in samples from five wells exceed the U.S. Environmental Protection Agency and the California Department of Health Services secondary drinking-water standard of 300 micrograms per liter. Water from 12 of 15 wells sampled contained concentrations of manganese that exceed the U.S. Environmental Protection Agency and the California Department of Health Services secondary drinking-water standard of 50 micrograms per liter. Two wells produced water that had boron in excess of the California Department of Health Services action level of 1 milligram per liter. Stable isotope, chlorofluorocarbon, and tritium data indicate that ground water in the area is a mixture of waters that recharged the aquifer system at different times. The presence of chlorofluorocarbons and tritium in water from the study area is evidence that modern recharge (post 1950) does take place. Water-temperature logs indicate that ground-water temperatures throughout the study area exceed 30?C at depths in excess of 600 feet. Further, water at

Extrapolation of earth-based solar irradiance measurements to exoatmospheric levels for broad-band and selected absorption-band observations

NASA Technical Reports Server (NTRS)

Reagan, John A.; Pilewskie, Peter A.; Scott-Fleming, Ian C.; Herman, Benjamin M.; Ben-David, Avishai

1987-01-01

Techniques for extrapolating earth-based spectral band measurements of directly transmitted solar irradiance to equivalent exoatmospheric signal levels were used to aid in determining system gain settings of the Halogen Occultation Experiment (HALOE) sunsensor being developed for the NASA Upper Atmosphere Research Satellite and for the Stratospheric Aerosol and Gas (SAGE) 2 instrument on the Earth Radiation Budget Satellite. A band transmittance approach was employed for the HALOE sunsensor which has a broad-band channel determined by the spectral responsivity of a silicon detector. A modified Langley plot approach, assuming a square-root law behavior for the water vapor transmittance, was used for the SAGE-2 940 nm water vapor channel.

Extrapolation of Earth-based solar irradiance measurements to exoatmospheric levels for broad-band and selected absorption-band observations

NASA Technical Reports Server (NTRS)

Reagan, J. A.; Pilewskie, P. A.; Scott-Fleming, I. C.; Hermann, B. M.

1986-01-01

Techniques for extrapolating Earth-based spectral band measurements of directly transmitted solar irradiance to equivalent exoatmospheric signal levels were used to aid in determining system gain settings of the Halogen Occultation Experiment (HALOE) sunsensor system being developed for the NASA Upper Atmosphere Research Satellite and for the Stratospheric Aerosol and Gas (SAGE) 2 instrument on the Earth Radiation Budget Satellite. A band transmittance approach was employed for the HALOE sunsensor which has a broad-band channel determined by the spectral responsivity of a silicon detector. A modified Langley plot approach, assuming a square-root law behavior for the water vapor transmittance, was used for the SAGE-2 940 nm water vapor channel.

Overall migration and specific migration of bisphenol A diglycidyl ether monomer and m-xylylenediamine hardener from an optimized epoxy-amine formulation into water-based food simulants.

PubMed

Simal Gándara, J; López Mahía, P; Paseiro Losada, P; Simal Lozano, J; Paz Abuín, S

1993-01-01

The overall and specific migrations of BADGE n = 0 monomer and m-XDA hardener from a BEPOX LAB 889 (Gairesa internal code), epoxy system cured at room temperature, into three water-based food simulants are studied. Hydrolysis of BADGE n = 0 was observed in all of these simulants, giving more polar products. We thus propose changing the EEC Directives, which at present only legislate for levels of BADGE n = 0 monomer in the simulants, to include the hydrolysis products of BADGE monomers. Another alternative would be to express all the migration levels due to BADGE and its derived products in terms of BADGE itself.

Impact of Past Land Use Changes on Drinking Water Quantity and Quality in Ljubljana Aquifer

NASA Astrophysics Data System (ADS)

Bracic Zeleznik, Branka; Cencur Curk, Barbara

2010-05-01

Most of the practical problems that we face today with the on-site management of drinking water sources and distribution of healthy drinking water, originate from past actions, interventions and political decisions. In Ljubljana, the capital of the Republic of Slovenia, underlying groundwater is the main drinking water source. The main threat to drinking water sources is constant input of pollutant loads from roads, roofs, sewers, industry and agricultural areas. The main problems are directly and indirectly related to the significant decrease of groundwater level and deterioration of groundwater quality observed in the last decades as an effect of land use practices under varying climate conditions. The Vodovod-Kanalizacija Public Utility is responsible for water supply of the city residents as well as for management of the water supply system, its surveillance and maintenance. In the past, the Ljubljana Municipality was responsible for the protection of water resources and the first delineation of groundwater protection areas was issued in Decree in 1955. In 2004 a Decree on the water protection zones for the aquifer of Ljubljansko polje on the state level was issued and passed the competences of proclamation of the water protection zones to the state. Spatial planning is a domain of The Municipality and land use is limited according to water protection legislation. For several observation wells long-time data sets about groundwater levels and quality are available, which enable us to analyse changes in groundwater quantity and quality parameters. From the data it is obvious that climate variations are affecting groundwater recharge. In addition, changing of land use affects groundwater quality. In spite of the Decree on the water protection there is a heavy pressure of investors to change land use plans and regulations on protection zones, which causes every day problems in managing the drinking water source. Groundwater management in Ljubljana demands strong and effective co-operation between state, municipality, public water supply company and consumers.

Direct aqueous measurement of 25-hydroxyvitamin D levels in a cellular environment by LC-MS/MS using the novel chemical derivatization reagent MDBP.

PubMed

Müller, Miriam J; Bruns, Heiko; Volmer, Dietrich A

2017-04-01

Vitamin D measurements in biological fluids by mass spectrometry are challenging at very low concentration levels. As a result, chemical derivatization is often employed to enhance the ionization properties of low abundant vitamin D compounds. Cookson-type reagents such as 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) or similar derivatives work well but require careful, water-free experimental conditions, as traces of water inactivate the reagent and inhibit or stop the derivatization reactions, thus making quantitative measurements in aqueous samples impossible. We describe a novel electrospray liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for determining 25-hydroxyvitamin D 3 (25(OH)D 3 ) directly in aqueous cellular systems using a new derivatization reagent, the ionic liquid 12-(maleimidyl)dodecyl-tri-n-butylphosphonium bromide (MDBP). The proof-of-concept for the MDBP assay was demonstrated by measuring the levels of 25(OH)D 3 in four different human cell types, namely T cells, helper T cells, B cells, and macrophages. In addition to the ability to determine the levels of 25(OH)D 3 directly in aqueous samples, the cellular integrity was maintained in our application. We show the time-dependent uptake of 25(OH)D 3 into the investigated cells to demonstrate the applicability of the new label. Furthermore, the MDBP derivatization technique may be equally useful in imaging mass spectrometry, where it could be used for response enhancements of spatially localized vitamin D metabolites on wet tissue surfaces, without destroying the integrity of the tissue surface. Graphical Abstract MDBP labelling of 25-hydroxyvitamin D in the extracellular space.

Hydrogeologic framework, hydrology, and refined conceptual model of groundwater flow for Coastal Plain aquifers at the Standard Chlorine of Delaware, Inc. Superfund Site, New Castle County, Delaware, 2005-12

USGS Publications Warehouse

Brayton, Michael J.; Cruz, Roberto M.; Myers, Luke; Degnan, James R.; Raffensperger, Jeff P.

2015-01-01

The regional hydrogeologic framework indicates that the site is underlain by Coastal Plain sediments of the Columbia, Merchantville, and Potomac Formations. Two primary aquifers underlying the site, the Columbia and the upper Potomac, are separated by the Merchantville Formation confining unit. Local groundwater flow in the surficial (Columbia) aquifer is controlled by topography and generally flows northward and discharges to nearby surface water. Regional flow within the Potomac aquifer is towards the southeast, and is strongly influenced by major water withdrawals locally. Previous investigations at the site indicated that contaminants, primarily benzene and chlorinated benzene compounds, were present in the Columbia aquifer in most locations; however, there were only limited detections in the upper Potomac aquifer as of 2004. From 2005 through 2012, the USGS designed a monitoring network, assisted with exploratory drilling, collected data at monitoring wells, conducted geophysical surveys, evaluated water-level responses in wells during pumping of a production well, and evaluated major aquifer withdrawals. Data collected through these efforts were used to refine the local conceptual flow system. The refined conceptual flow system for the site includes: (a) identification of gaps in confining units in the study area, (b) identification and correlation of multiple water-bearing sand intervals within the upper Potomac Formation, (c) connections between groundwater and surface water, (d) connections between shallow and deeper groundwater, (e) new water-level (or potentiometric surface) maps and inferred flow directions, and (f) identification of major local pumping well influences. The implications of the revised conceptual flow system on the occurrence and movement of site contaminants are that the resulting detection of contaminants in the upper Potomac aquifer at specific well locations can be attributed primarily to either advective lateral transport, direct vertical contaminant transport, or a combination of vertical and lateral movement resulting from changes in water withdrawal rates over time.

Seasonal changes of mercury reduction and methylation in Gulf of Trieste (north Adriatic Sea)

NASA Astrophysics Data System (ADS)

Horvat, M.; Bratkic, A.; Koron, N.; Faganeli, J.; Ribeiro Guevara, S.; Tinta, T.

2014-12-01

We have successfully improved and applied the 197Hg radiotracer method during the sampling campaign from March until November 2011, collecting and incubating sediments and waters with low 197Hg2+ additions without significantly increasing natural levels. The evolution of Me197Hg and DGM197 was followed. In addition, we have performed Hg speciation of the water column and sediment, determined diversity of microbial community and investigated microbial resistance to Hg through presence of merA and merB genes. Our results showed repeatedly that methylation does not occur in the water column of the GoT, and confirmed that sediments are the principal methylation site, as well as the source of MeHg to the water column. Its formation seems to be closely linked to nutrient cycling at the sediment-water interface, where degradation of organic matter with accompanying oxygen consumption significantly stimulates MeHg production (range 0.85 pM - 3.39 pM). The water column showed a pronounced capability for 197Hg2+ reduction (up to 25% d-1), confirming that the GoT is a source of Hg to the atmosphere. Whether reduction was directly linked to genetic resistance; was a consequence of non-specific redox reactions or of other microbial mechanisms could not be demonstrated. Neither merA nor merB genes were detected, but the microbial community structure was changing in the water column seasonally, as did the reduction rates in the experiments. Most importantly, it was shown that 197Hg methodology is sensitive enough to follow Hg biogeochemical transformations at environmental levels. The advantage is that the minimal additions of 197Hg do not disturb the natural processes occurring in the environment and that very small changes can be detected. Hg stress in the Gulf can directly manifest itself in biota and consequently result in a threat to environmental and public health and therefore needs to be seen in the light of changing global climate and marine environment.

Measuring domestic water use: a systematic review of methodologies that measure unmetered water use in low-income settings.

PubMed

Tamason, Charlotte C; Bessias, Sophia; Villada, Adriana; Tulsiani, Suhella M; Ensink, Jeroen H J; Gurley, Emily S; Mackie Jensen, Peter Kjaer

2016-11-01

To present a systematic review of methods for measuring domestic water use in settings where water meters cannot be used. We systematically searched EMBASE, PubMed, Water Intelligence Online, Water Engineering and Development Center, IEEExplore, Scielo, and Science Direct databases for articles that reported methodologies for measuring water use at the household level where water metering infrastructure was absent or incomplete. A narrative review explored similarities and differences between the included studies and provide recommendations for future research in water use. A total of 21 studies were included in the review. Methods ranged from single-day to 14-consecutive-day visits, and water use recall ranged from 12 h to 7 days. Data were collected using questionnaires, observations or both. Many studies only collected information on water that was carried into the household, and some failed to mention whether water was used outside the home. Water use in the selected studies was found to range from two to 113 l per capita per day. No standardised methods for measuring unmetered water use were found, which brings into question the validity and comparability of studies that have measured unmetered water use. In future studies, it will be essential to define all components that make up water use and determine how they will be measured. A pre-study that involves observations and direct measurements during water collection periods (these will have to be determined through questioning) should be used to determine optimal methods for obtaining water use information in a survey. Day-to-day and seasonal variation should be included. A study that investigates water use recall is warranted to further develop standardised methods to measure water use; in the meantime, water use recall should be limited to 24 h or fewer. © 2016 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

Observation of Water-Protein Interaction Dynamics with Broadband Two-Dimensional Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

De Marco, Luigi; Haky, Andrew; Tokmakoff, Andrei

Two-dimensional infrared (2D IR) spectroscopy has proven itself an indispensable tool for studying molecular dynamics and intermolecular interactions on ultrafast timescales. Using a novel source of broadband mid-IR pulses, we have collected 2D IR spectra of protein films at varying levels of hydration. With 2D IR, we can directly observe coupling between water's motions and the protein's. Protein films provide us with the ability to discriminate hydration waters from bulk water and thus give us access to studying water dynamics along the protein backbone, fluctuations in the protein structure, and the interplay between the molecular dynamics of the two. We present two representative protein films: poly-L-proline (PLP) and hen egg-white lysozyme (HEWL). Having no N-H groups, PLP allows us to look at water dynamics without interference from resonant energy transfer between the protein N-H stretch and the water O-H stretch. We conclude that at low hydration levels water-protein interactions dominate, and the water's dynamics are tied to those of the protein. In HEWL films, we take advantage of the robust secondary structure to partially deuterate the film, allowing us to spectrally distinguish the protein core from the exterior. From this, we show that resonant energy transfer to water provides an effective means of dissipating excess energy within the protein, while maintaining the structure. These methods are general and can easily be extended to studying specific protein-water interactions.

Dynamics of water in sulfonated poly(phenylene) membranes

NASA Astrophysics Data System (ADS)

Osti, Naresh; Etampawala, Thusitha; Shrestha, Umesh; Perahia, Dvora; Cornelius, Christopher

2011-03-01

The dynamics of water in networks formed by highly rigid ionic polymers, sulfonated poly(phenylene) as observed by quasi elastic neutron scattering (QENS) is presented. These rigid ionic polymers have potential as effective ion exchange membranes with impact on a large number of applications from water purification to clean energy, where its rigidity distinguishes it from other ionic polymers. Its transport characteristics are affected by its rigidness as well as by direct interactions with the solvent. Our QENS studies as a function of sulfonation levels, temperature and solvent content have shown that on the time scale of the measurement, the polymers are rigid. While macroscopically all samples swell, and transport water, the water molecules appear locally rather confined. Water however remind non-frozen to subzero temperatures. The results will be discussed in view of theoretical models including continues diffusion and hopping of solvent molecules.

Water intensity of transportation.

PubMed

King, Carey W; Webber, Michael E

2008-11-01

As the need for alternative transportation fuels increases, it is important to understand the many effects of introducing fuels based upon feedstocks other than petroleum. Water intensity in "gallons of water per mile traveled" is one method to measure these effects on the consumer level. In this paper we investigate the water intensity for light duty vehicle (LDV) travel using selected fuels based upon petroleum, natural gas, unconventional fossil fuels, hydrogen, electricity, and two biofuels (ethanol from corn and biodiesel from soy). Fuels more directly derived from fossil fuels are less water intensive than those derived either indirectly from fossil fuels (e.g., through electricity generation) or directly from biomass. The lowest water consumptive (<0.15 gal H20/mile) and withdrawal (<1 gal H2O/mile) rates are for LDVs using conventional petroleum-based gasoline and diesel, nonirrigated biofuels, hydrogen derived from methane or electrolysis via nonthermal renewable electricity, and electricity derived from nonthermal renewable sources. LDVs running on electricity and hydrogen derived from the aggregate U.S. grid (heavily based upon fossil fuel and nuclear steam-electric power generation) withdraw 5-20 times and consume nearly 2-5 times more water than by using petroleum gasoline. The water intensities (gal H20/mile) of LDVs operating on biofuels derived from crops irrigated in the United States at average rates is 28 and 36 for corn ethanol (E85) for consumption and withdrawal, respectively. For soy-derived biodiesel the average consumption and withdrawal rates are 8 and 10 gal H2O/mile.

Variation of Strom Surge Propagation in a Shallow Estuary with Sea Level Rise

NASA Astrophysics Data System (ADS)

Herrington, T. O., Jr.; Blumberg, A. F.

2014-12-01

Hurricane Sandy made landfall along the New Jersey coast at 8pm EDT on October 29th, 2012. At landfall wind gusts of between 129 and 145 km/hr were recorded in New York and New Jersey. The large wind field associated with the storm generated an extreme storm surge north of the eye at landfall resulting in high-velocity overland storm surge along the northern barrier Islands of the Barnegat Bay followed 7 hours later by a rapid rise in water level along the bayside of the barrier islands. A high-resolution, hydrodynamic model for the Barnegat Bay estuary; including its vast intertidal areas, has been developed and validated to simulate the observed Sandy storm surge. The Barnegat Bay Inundation Model (BBIMS) has a constant 100m resolution and is nested within the three dimensional Stevens NYHOPS ocean circulation model at its offshore open boundary. Wetting and drying of land features in the model's external time step is as low as 0.1 sec in its 2D barotropic mode. This mode provides for the dynamic prediction of depth integrated flood elevations and velocities across land features during inundation events. The BBIMS was calibrated using the NYHOPS hindcast of Hurricane Sandy. The hindcast utilized Sandy over ocean wind field and atmospheric pressure data, offshore wave and tidal boundary forcing, atmospheric heat fluxes, interior stream flow data and was validated against observed water levels and measured high water marks. A comparison against 6 water level time series measured by USGS tide gauges located in the Barnegat Bay verified that the model is able to capture the spatial and temporal variation of water levels in the Bay observed during Hurricane Sandy. A comparison against the verified high water marks found that the model is capable of hincasting overland water elevation to within 0.63ft (one standard deviation) at 71% of the total water marks measured. The modeling results show that strong northerly winds along the axis of the estuary prior to landfall suppressed the storm surge in the northern portion of the Bay. A rapid shift in wind direction to southerly winds after landfall allowed the surge to propagate north up the estuary as a shallow water wave (Figure 1). The effect of future sea levels on surge propagation in the estuary is investigated through increases in model mean sea level.

Permeability estimates from artificial drawdown and natural refill experiments at Solfatara volcano, Italy

NASA Astrophysics Data System (ADS)

Woith, Heiko; Chiodini, Giovanni; Mangiacapra, Annarita; Wang, Rongjiang

2016-04-01

The hydrothermal system beneath Campi Flegrei is strongly affected by sub-surface processes as manifested by a geothermal "plume" below Solfatara, associated with the formation of mud-pools (Fangaia), fumaroles (Bocca Grande, Pisciarelli), and thermal springs (Agnano). Within the frame of MED-SUV (The MED-SUV project has received funding from the European Union Seventh Framework Programme FP7 under Grant agreement no 308665), pressure transients in the hydrothermal system of Campi Flegrei are being continuously monitored at fumaroles, mudpools, hot springs, and geothermal wells. In total, waterlevel and temperature is recorded at 8 sites across the hydrothermal plume along a profile aligned between Agnano Termal in the East and Fangaia in the West. Autonomous devices are used to record the water level and water temperature at 10 minute intervals. At Fangaia mudpool water level and water temperature are dominantly controlled by rain water. Thus, the pool is refilled episodically. Contrary, the water level at a well producing hot water (82°C) for the Pisciarelli tennis club drops and recovers at nearly regular intervals. The induced water level changes are of the order of 1-2m and 3-4m in case of the mudpool and the hot-water-well, respectively. At first glance, both monitoring sites might seem to be fully useless to access natural changes in the Campi Flegrei fluid system. At a second thought, both timeseries provide a unique opportunity to monitor potential permeability changes in the aquifer system. A similar approach had been proposed to deduce earthquake-related permeability changes from Earth tide variations. Contrary to the indirect Earth tide approach, we have the chance to estimate the hydraulic aquifer properties from our monitoring data directly, since each time series contains a sequence of discrete hydraulic tests - namely drawdown tests and refill experiments. Although our Cooper-Jacob approach is really crude, we obtained reasonable permeability estimates for both sites. Preliminary permeability timeseries are presented.

Silver migration from silver-modified activated carbon applied as a water filtration medium in classic cartridges of jug filter systems.

PubMed

Garboś, S; Swięcicka, D

2012-01-01

A comprehensive study was undertaken in order to examine the possible adverse effect of jug filter systems (JFSs) on the quality of filtered water taking into account the released amounts of silver (Ag) into the filtered test water. Nine brands of JFSs (A-I) were investigated according to BS 8427:2004 using a validated ICP/MS method. Essential modification of BS 8427:2004 within the domain of the composite sample preparation was proposed and applied during the tests. The established grand mean concentrations of released Ag from A-H classic cartridges (containing Ag-modified activated carbon and ion exchange resins) and I classic cartridge (containing non-modified activated carbon and ion exchange resin) installed in corresponding JFSs were in the range of 2.6-13.1 µg l⁻¹ and lower than 0.014 µg l⁻¹, respectively. These values were applied for the estimation of the daily intakes of Ag connected with the consumption of water filtered using JFSs (ranging from < 0.0004 to 0.374 µg kg⁻¹ day⁻¹). After taking into account the grand mean concentrations of Ag established during the whole cycle of exploitation for nine JFSs and on the basis of available toxicological data for this element, no long-term risk for human health with respect to appearance of argyria (a condition caused by improper exposure to the Ag or Ag compounds) could be expected (the Hazard Quotient indices estimated as ratios of the daily intakes to the reference dose of Ag were equal or lower than 0.075). Ag-modified activated carbon is not included in the positive list of the authorised substances of the European Commission Regulation (EU) No. 10/2011. Additionally, this material has not been approved by European Food Safety Authority (EFSA). A part of water filtered by JFSs can be directly consumed as drinking water and additionally the remaining water can be applied for the preparation of food products (drinks, soups, etc.). In both cases the quality of water has to fulfil the requirements listed in Directive 98/83/EC (Regulation (EC) No. 178/2002 defines the quality of water intentionally incorporated into the food after the point of compliance as defined in Article 6 of Directive 98/83/EC). However, it should be underlined that point-of-use water treatment units (including JFSs) are not regulated under Directive 98/83/EC and additionally the parametric value for Ag is not included in this document. Therefore, a provisional migration limit for Ag leached from JFSs at the level of 25 µg l⁻¹ was proposed. This value for Ag would limit intake to less than 13% of the human No Observed Adverse Effect Level (NOAEL) (0.39 mg person⁻¹ day⁻¹), using an assumption that each day 2 L of filtered water is consumed containing this metal at the provisional migration limit. All the JFSs tested meet this requirement.

Design of a Real-Time Ground-Water Level Monitoring Network and Portrayal of Hydrologic Data in Southern Florida

USGS Publications Warehouse

Prinos, Scott T.; Lietz, A.C.; Irvin, R.B.

2002-01-01

Ground-water resources in southern Florida are under increasing stress caused by a rapid growth in population. As a result of increased demands on aquifers, water managers need more timely and accurate assessments of ground-water conditions in order to avoid or reduce adverse effects such as saltwater intrusion, loss of pumpage in residential water-supply wells, land-surface subsidence, and aquifer compaction. Hydrologic data were analyzed from three aquifer systems in southern Florida: the surficial aquifer system, which includes the Biscayne aquifer; the intermediate aquifer system, which includes the sandstone and mid-Hawthorn aquifers; and the Florida aquifer system represented by the lower Hawthorn producing zone. Long-term water-level trends were analyzed using the Seasonal Kendall trend test in 83 monitoring wells with a daily-value record spanning 26 years (1974-99). The majority of the wells with data for this period were in the Biscayne aquifer in southeastern Florida. Only 14 wells in southwestern Florida aquifers and 9 in the surficial aquifer system of Martin and Palm Beach Counties had data for the full period. Because many monitoring wells did not have data for this full period, several shorter periods were evaluated as well. The trend tests revealed small but statistically significant upward trends in most aquifers, but large and localized downward trends in the sandstone and mid-Hawthorn aquifers. Monthly means of maximum daily water levels from 246 wells were compared to monthly rainfall totals from rainfall stations in southwestern and southeastern Florida in order to determine which monitoring wells most clearly indicated decreases in water levels that corresponded to prolonged rainfall shortages. Of this total, 104 wells had periods of record over 20 years (after considering missing record) and could be compared against several drought periods. After factors such as lag, seasonal cyclicity, and cumulative functions were considered, the timing of minimum values of water level from 15 ground-water monitoring wells and average minimum rainfall values agreed 57 to 62 percent of the time over a 20 to 26 year period. On average, the timing of water-level minimums and rainfall minimums agreed about 52 percent of the time, and in some cases only agreed 29 percent of the time. A regression analysis was used to evaluate daily water levels from 203 monitoring wells that are currently, or recently had been, part of the network to determine which wells were most representative of each aquifer. The regression also was used to determine which wells provided data that could be used to provide estimations of water levels at other wells in the aquifer with a coefficient of determination (R2 value) from the regression of 0.64 or greater. In all, the regression analysis alone indicated that 35 wells, generally with 10 years or more of data, could be used to directly monitor water levels or to estimate water levels at 180 of 203 wells (89 percent of the network). Ultimately, factors such as existing instrumentation, well construction, long-term water-level trends, and variations of water level and chloride concentration were considered together with the R2 results in designing the final network. The Seasonal Kendall trend test was used to examine trends in ground-water chloride concentrations in 113 wells. Of these wells, 61 showed statistically significant trends. Fifty-six percent (34 of 61 wells) of the observed trends in chloride concentration were upward and 44 percent (27 of 61 wells) were downward. The relation between water level and chloride concentration in 114 ground-water wells was examined using Spearman's r and Pearson's r correlation coefficients. Statistically significant results showed both positive and negative relations. Based on the results of statistical analyses, period of record, well construction, and existing satellite telemetry, 33 monitoring wells were selected that could be used to a

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

U.S. Geological Survey Georgia Water Science Center and City of Brunswick- Glynn County Cooperative Water Program-Summary of Activities, July 2005 through June 2006

USGS Publications Warehouse

Cherry, Gregory S.

2007-01-01

Since 1959, the U.S. Geological Survey has conducted a cooperative water resources program (CWP) with the City of Brunswick and Glynn County in the Brunswick, Georgia, area. Since the late 1950s, the salinity of ground water in the Upper Floridan aquifer near downtown Brunswick, Georgia, has been increasing, and its occurrence has been detected across an area of increasing size. Pumping of the Upper Floridan aquifer near downtown Brunswick has lowered water levels in the aquifer and resulted in an upward hydraulic gradient between the highly saline parts of the Lower Floridan aquifer and the normally fresh Upper Floridan aquifer. Saltwater likely enters the Upper Floridan aquifer through localized, vertically oriented conduits of relatively high permeability and moves laterally in response to the distribution of stresses within the aquifer. The Brunswick-Glynn County CWP for fiscal year 2006 includes the operation and maintenance of 12 continuous water-level recorders. In addition, water-level data were collected from 52 wells and water from 70 wells was analyzed for chloride concentration during June 2005. Geophysical logs were obtained from one well to assess whether the cause of elevated chloride concentration could be due to leaky well casing. A summary of the Georgia Department of Natural Resources, Environmental Protection Division (GaEPD) Georgia Coastal Sound Science Initiative (CSSI) activities that directly benefit the CWP-Brunswick-Glynn County is included in this report. The GaEPD CSSI is a program of scientific and feasibility studies to support development of a final strategy to protect the Upper Floridan aquifer from saltwater contamination. These data presented in this report are needed by State and local authorities to manage water resources effectively in the coastal area of Georgia.

Study on ecological regulation of coastal plain sluice

NASA Astrophysics Data System (ADS)

Yu, Wengong; Geng, Bing; Yu, Huanfei; Yu, Hongbo

2018-02-01

Coastal plains are densely populated and economically developed, therefore their importance is self-evident. However, there are some problems related with water in coastal plains, such as low flood control capacity and severe water pollution. Due to complicated river network hydrodynamic force, changeable flow direction and uncertain flood concentration and propagation mechanism, it is rather difficult to use sluice scheduling to realize flood control and tackle water pollution. On the base of the measured hydrological data during once-in-a-century Fitow typhoon in 2013 in Yuyao city, by typical analysis, theoretical analysis and process simulation, some key technologies were researched systematically including plain river network sluice ecological scheduling, “one tide” flood control and drainage scheduling and ecological running water scheduling. In the end, single factor health diagnostic evaluation, unit hydrograph of plain water level and evening tide scheduling were put forward.

The global topography mission gains momentum

USGS Publications Warehouse

Farr, Tom; Evans, Diane; Zebker, Howard; Harding, David; Bufton, Jack; Dixon, Timothy; Vetrella, S.; Gesch, Dean B.

1995-01-01

An accurate description of the surface elevation of the Earth is of fundamental importance to many branches of Earth science. Continental topographic data are required for studies of hydrology, ecology, glaciology, geomorphology, and atmospheric circulation. For example, in hydrologic and terrestrial ecosystem studies, topography exerts significant control on intercepted solar radiation, water runoff and subsurface water inventory, microclimate, vegetation type and distribution, and soil development. The topography of the polar ice caps and mountain glaciers directly reflects ice-flow dynamics and is closely linked to global climate and sea level change.

Analysis of Tests of Subsurface Injection, Storage, and Recovery of Freshwater in Lancaster, Antelope Valley, California

USGS Publications Warehouse

Phillips, Steven P.; Carlson, Carl S.; Metzger, Loren F.; Howle, James F.; Galloway, Devin L.; Sneed, Michelle; Ikehara, Marti E.; Hudnut, Kenneth W.; King, Nancy E.

2003-01-01

Ground-water levels in Lancaster, California, declined more than 200 feet during the 20th century, resulting in reduced ground-water supplies and more than 6 feet of land subsidence. Facing continuing population growth, water managers are seeking solutions to these problems. Injection of imported, treated fresh water into the aquifer system when it is most available and least expensive, for later use during high-demand periods, is being evaluated as part of a management solution. The U.S. Geological Survey, in cooperation with the Los Angeles County Department of Public Works and the Antelope Valley-East Kern Water Agency, monitored a pilot injection program, analyzed the hydraulic and subsidence-related effects of injection, and developed a simulation/optimization model to help evaluate the effectiveness of using existing and proposed wells in an injection program for halting the decline of ground-water levels and avoiding future land subsidence while meeting increasing ground-water demand. A variety of methods were used to measure aquifer-system response to injection. Water levels were measured continuously in nested (multi-depth) piezometers and monitoring wells and periodically in other wells that were within several miles of the injection site. Microgravity surveys were done to estimate changes in the elevation of the water table in the absence of wells and to estimate specific yield. Aquifer-system deformation was measured directly and continuously using a dual borehole extensometer and indirectly using continuous Global Positioning System (GPS), first-order spirit leveling, and an array of tiltmeters. The injected water and extracted water were sampled periodically and analyzed for constituents, including chloride and trihalomethanes. Measured injection rates of about 750 gallons per minute (gal/min) per well at the injection site during a 5-month period showed that injection at or above the average extraction rates at that site (about 800 gal/min) was hydraulically feasible. Analyses of these data took many forms. Coupled measurements of gravity and water-level change were used to estimate the specific yield near the injection wells, which, in turn, was used to estimate areal water-table changes from distributed measurements of gravity change. Values of the skeletal components of aquifer-system storage, which are key subsidence-related characteristics of the system, were derived from continuous measurements of water levels and aquifer-system deformation. A numerical model of ground-water flow was developed for the area surrounding Lancaster and used to estimate horizontal and vertical hydraulic conductivities. A chemical mass balance was done to estimate the recovery of injected water. The ground-water-flow model was used to project changes in ground-water levels for 10 years into the future, assuming no injection, no change in pumping distribution, and forecasted increases in ground-water demand. Simulated ground-water levels decreased throughout the Lancaster area, suggesting that land subsidence would continue as would the depletion of ground-water supplies and an associated loss of well production capacity. A simulation/optimization model was developed to help identify optimal injection and extraction rates for 16 existing and 13 proposed wells to avoid future land subsidence and to minimize loss of well production capacity while meeting increasing ground-water demands. Results of model simulations suggest that these objectives can be met with phased installation of the proposed wells during the 10-year period. Water quality was not considered in the optimization, but chemical-mass-balance results indicate that a sustained injection program likely would have residual effects on the chemistry of ground water.

Model-Aided Altimeter-Based Water Level Forecasting System in Mekong River

NASA Astrophysics Data System (ADS)

Chang, C. H.; Lee, H.; Hossain, F.; Okeowo, M. A.; Basnayake, S. B.; Jayasinghe, S.; Saah, D. S.; Anderson, E.; Hwang, E.

2017-12-01

Mekong River, one of the massive river systems in the world, has drainage area of about 795,000 km2 covering six countries. People living in its drainage area highly rely on resources given by the river in terms of agriculture, fishery, and hydropower. Monitoring and forecasting the water level in a timely manner, is urgently needed over the Mekong River. Recently, using TOPEX/Poseidon (T/P) altimetry water level measurements in India, Biancamaria et al. [2011] has demonstrated the capability of an altimeter-based flood forecasting system in Bangladesh, with RMSE from 0.6 - 0.8 m for lead times up to 5 days on 10-day basis due to T/P's repeat period. Hossain et al. [2013] further established a daily water level forecasting system in Bangladesh using observations from Jason-2 in India and HEC-RAS hydraulic model, with RMSE from 0.5 - 1.5 m and an underestimating mean bias of 0.25 - 1.25 m. However, such daily forecasting system relies on a collection of Jason-2 virtual stations (VSs) to ensure frequent sampling and data availability. Since the Mekong River is a meridional river with few number of VSs, the direct application of this system to the Mekong River becomes challenging. To address this problem, we propose a model-aided altimeter-based forecasting system. The discharge output by Variable Infiltration Capacity hydrologic model is used to reconstruct a daily water level product at upstream Jason-2 VSs based on the discharge-to-level rating curve. The reconstructed daily water level is then used to perform regression analysis with downstream in-situ water level to build regression models, which are used to forecast a daily water level. In the middle reach of the Mekong River from Nakhon Phanom to Kratie, a 3-day lead time forecasting can reach RMSE about 0.7 - 1.3 m with correlation coefficient around 0.95. For the lower reach of the Mekong River, the water flow becomes more complicated due to the reversal flow between the Tonle Sap Lake and the Mekong River, while ocean tide can also propagate into this region. By considering the influence of Tonle Sap Lake and the Mekong River through multi-variable regression analysis, the forecasting results from Prek Kdam to Chau Doc/Tan Chau reach RMSE from about 0.3 - 0.65 m and correlation coefficient about 0.93- 0.97 with 5-day lead time.