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Sample records for surface waters south

  1. Treatability of South African surface waters by enhanced coagulation

    African Journals Online (AJOL)

    2013-06-05

    Jun 5, 2013 ... The majority of South African inland surface water sources are compromised due to a ... minimising residual coagulant, minimising sludge production .... included as being indicative of the worst effects of indirect reuse.

  2. Groundwater/Surface-Water Interaction in the Context of South African Water Policy

    Science.gov (United States)

    Levy, J.; Xu, Y.

    2010-12-01

    Groundwater/surface-water interaction is receiving increasing focus in Africa due to its importance to ecologic systems and sustainability. South Africa’s 1998 National Water Act (NWA) recognized water as a basic human right and its importance for ecological sustainability. Ecological integrity of water resources was considered an important component in redressing past social inequities, eliminating poverty, and encouraging economic development. Under the NWA, groundwater-use licenses are granted only after setting aside the groundwater Reserve, the amount of water needed to supply basic human needs and preserve a minimum degree of ecological integrity. One challenge to successful implementation of the NWA, therefore, is the accurate quantification of groundwater contributions to aquatic ecosystems. This is especially true considering that so many of South Africa’s aquifers are in highly heterogeneous and anisotropic fractured-rock settings. The most common approach taken in South Africa is estimation of average annual flux rates at the regional scale of quaternary catchments with baseflow separation techniques and then applying a water-budget approach, subtracting the groundwater discharge rate from the recharge rate. The water-balance approach might be a good first step, but it ignores spatial and temporal variability, potentially missing the local impacts associated with placement of production boreholes. Identification of discrete areas of groundwater discharge could be achieved with stable-isotopic and geochemical analyses and vegetative mapping. Groundwater-flow modeling should be used where possible as it holistically incorporates available data and can predict impacts of groundwater extraction and development based on the relative positions of boreholes and surface-water bodies. Sustainable development entails recognition of the trade-offs between preservation and development. There will always be scientific uncertainty associated with estimation and

  3. Plutonium and {sup 137}Cs in surface water of the South Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, K.; Komura, K. [Meteorological Research Institute, Nagamine 1-1, Tsukuba, Ibaraki 305-0052 (Japan); Low Level Radioactivity Laboratory, Kanazawa University, Wake, Nomi, Ishikawa 923-1224 (Japan); Aoyama, M. [Meteorological Research Institute, Nagamine 1-1, Tsukuba, Ibaraki 305-0052 (Japan); Fukasawa, M. [Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15, Natsushima, Yokosuka 237-0061 (Japan); Kim, C.S. [Korea Institute of Nuclear Safety, Daeduk-Danji Daejeon 305-336 (Korea); Povinec, P.P. [Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, SK-842 48, Bratislava (Slovakia); Sanchez-Cabeza, J.A. [Marine Environment Laboratories, International Atomic Energy Agency, 4 Quai Antoine 1er, MC98000 (Monaco)

    2007-08-01

    The present plutonium and {sup 137}Cs concentrations in South Pacific Ocean surface waters were determined. The water samples were collected in the South Pacific mid-latitude region (32.5 S) during the BEAGLE expedition conducted in 2003-04 by JAMSTEC. {sup 239,240}Pu concentrations in surface seawater of the South Pacific were in the range of 0.5 to 4.1 mBq m{sup -3}, whereas {sup 137}Cs concentrations ranged from 0.07 to 1.7 Bq m{sup -3}. The observed {sup 239,240}Pu and {sup 137}Cs concentrations in the South Pacific were almost of the same level as those in the North Pacific subtropical gyre. The surface {sup 239,240}Pu in the South Pacific subtropical gyre showed larger spatial variations than {sup 137}Cs, as it may be affected by physical and biogeochemical processes. The {sup 239,240}Pu/{sup 137}Cs activity ratios, which reflect biogeochemical processes in seawater, were generally smaller than that observed in global fallout, except for the most eastern station. The {sup 239,240}Pu/{sup 137}Cs ratios in the South Pacific tend to be higher than that in the North Pacific. The relationships between anthropogenic radionuclides and oceanographic parameters such as salinity and nutrients were examined. The {sup 137}Cs concentrations in the western South Pacific (the Tasman Sea) and the eastern South Pacific were negatively correlated with the phosphate concentration, whereas there is no correlation between the {sup 137}Cs and nutrients concentrations in the South Pacific subtropical gyre. The mutual relationships between anthropogenic radionuclides and oceanographic parameters are important for better understanding of transport processes of anthropogenic radionuclides and their fate in the South Pacific. (author)

  4. Treatability of South African surface waters by activated carbon

    African Journals Online (AJOL)

    This suggests that GAC usage rate is not only a function of the initial UV absorbance but also ... and dissolved organic carbon (DOC) data suggested that for some waters UV254 ..... analysis was done with the UV254 absorbance value, as this.

  5. Dissolved Cu, Pb, Zn and Cd in the South China Sea surface waters

    Institute of Scientific and Technical Information of China (English)

    Huo Wenmian; Ji Weidong; Xu Kuncan

    2001-01-01

    A total of 106 surface water samples were collected in the South China Sea during two transects in June and December 1998. The samples were collected with strictly contamination free procedure and trace metals were measured by clean laboratory methods and GFAAS. The mean concentrations for the dissolved fractions are: Cu 0.100 μg/dm3, Pb 0.060 μg/dm3, Zn 0.086 μg/dm3, Cd 0.007 μg/dm3, which is close to the world open ocean's level. The spatial distribution of the trace heavy metals shows higher concentrations in offshore area and lower concentrations in the central in the South China Sea, and the concentrations decrease with the distance from the offshore, which suggests the existence of significant continental shelf input of the trace heavy metals. The correlationship among the elements is better in summer than that in winter. Cu is positively correlated with Cd in both seasons and it is also found for the first time that they are positively correlated with nutrients in the South China Sea surface waters which further indicate the biogeochemical cycle of these elements in the marine environment. The baseline value of Cu, Pb, Zn, Cd in the South China Sea surface waters is obtained through statistical analysis.

  6. Preliminary investigation of radon concentration in surface water and drinking water in Shenzhen City, South China.

    Science.gov (United States)

    Li, Ting; Wang, Nanping; Li, Shijun

    2015-11-01

    A radon survey in surface water and drinking water was conducted using a portable degassing system associated with an ionisation chamber AlphaGUARD (PQ2000) for understanding levels of dissolved radon ((222)Rn) concentration in different types of water sources and risk assessment of radon in drinking water in Shenzhen City (SC) with a population of 10 628 900 in 2013, Guangdong Province of China. The measurements show that arithmetic means ± standard deviations of radon ((222)Rn) concentration are 52.05 ± 6.64, 0.29 ± 0.26, 0.15 ± 0.23 and 0.37 ± 0.42 kBq m(-3) in spring water, surface water, large and small public water supplies, respectively. Only radon concentrations of two water samples collected in mountainous areas are more than 11.10 kBq m(-3), exceeding the limit of radon concentration in drinking water stipulated by the national standard of China (GB5749-2006). The annual effective doses due to radon in drinking water were also calculated. The investigation suggests that there are no risks caused by radon in the drinking water in SC.

  7. Occurrence and removal of pharmaceuticals and endocrine disruptors in South Korean surface, drinking, and waste waters.

    Science.gov (United States)

    Kim, Sang D; Cho, Jaeweon; Kim, In S; Vanderford, Brett J; Snyder, Shane A

    2007-03-01

    Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) was used to measure the concentrations of 14 pharmaceuticals, 6 hormones, 2 antibiotics, 3 personal care products (PCPs), and 1 flame retardant in surface waters and wastewater treatment plant effluents in South Korea. Tris (2-chloroethyl) phosphate (TCEP), iopromide, naproxen, carbamazepine, and caffeine were quite frequently observed (>80%) in both surface waters and effluents. The analytes of greatest concentration were iopromide, TCEP, sulfamethoxazole, and carbamazepine. However, the primary estrogen hormones, 17alpha-ethynylestradiol and 17beta-estradiol, were rarely detected, while estrone was detected in both surface water and wastewater effluent. The elimination of these chemicals during drinking water and wastewater treatment processes at full- and pilot-scale also was investigated. Conventional drinking water treatment methods were relatively inefficient for contaminant removal, while efficient removal (approximately equal to 99%) was achieved by granular activated carbon (GAC). In wastewater treatment processes, membrane bioreactors (MBR) showed limited target compound removal, but were effective at eliminating hormones and some pharmaceuticals (e.g., acetaminophen, ibuprofen, and caffeine). Membrane filtration processes using reverse osmosis (RO) and nanofiltration (NF) showed excellent removal (>95%) for all target analytes.

  8. A Glimpse at South Atlantic Deep and Surface Water Evolution over the Last 40 Ky

    Science.gov (United States)

    Waelbroeck, C.; Vazquez Riveiros, N.; Arz, H. W.; Gottschalk, J.; Skinner, L. C.; Dokken, T. M.

    2014-12-01

    intermediate water, and circumpolar deep water. We further compare core MD08-3167 records with benthic isotopic and surface records from other well-dated South Atlantic cores of comparable temporal resolution, i.e. western tropical Atlantic core GeoB3910, and Sub-Antarctic cores MD07-3076Q and TNO57-21 (Barker and Diz, 2014).

  9. Contamination of rural surface and ground water by endosulfan in farming areas of the Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    London Leslie

    2003-03-01

    Full Text Available Abstract Background In South Africa there is little data on environmental pollution of rural water sources by agrochemicals. Methods This study investigated pesticide contamination of ground and surface water in three intensive agricultural areas in the Western Cape: the Hex River Valley, Grabouw and Piketberg. Monitoring for endosulfan and chlorpyrifos at low levels was conducted as well as screening for other pesticides. Results The quantification limit for endosulfan was 0.1 μg/L. Endosulfan was found to be widespread in ground water, surface water and drinking water. The contamination was mostly at low levels, but regularly exceeded the European Drinking Water Standard of 0.1 μg/L. The two most contaminated sites were a sub-surface drain in the Hex River Valley and a dam in Grabouw, with 0.83 ± 1.0 μg/L (n = 21 and 3.16 ± 3.5 μg/L (n = 13 average endosulfan levels respectively. Other pesticides including chlorpyrifos, azinphos-methyl, fenarimol, iprodione, deltamethrin, penconazole and prothiofos were detected. Endosulfan was most frequently detected in Grabouw (69% followed by Hex River (46% and Piketberg (39%. Detections were more frequent in surface water (47% than in groundwater (32% and coincided with irrigation, and to a lesser extent, to spraying and trigger rains. Total dietary endosulfan intake calculated from levels found in drinking water did not exceed the Joint WHO/FAO Meeting on Pesticide Residues (JMPR criteria. Conclusion The study has shown the need for monitoring of pesticide contamination in surface and groundwater, and the development of drinking water quality standards for specific pesticides in South Africa.

  10. South Asian summer monsoon variability during the last ~54 kyrs inferred from surface water salinity and river run off proxies

    Digital Repository Service at National Institute of Oceanography (India)

    Gebregiorgis, D.; Hathorne, E.C.; Sijinkumar, A.V; Nath, B.N.; Nurnberg, D.; Frank, M.

    : Quat. Sci. Rev., vol.138; 2016; 6-15 South Asian Summer Monsoon variability during the last ~54 kyrs inferred from surface water salinity and river run off proxies D. Gebregiorgis1, E.C. Hathorne1, A.V. Sijinkumar2, B. Nagender Nath3, D. Nürnberg... leach with 100 μL 0.001 M HNO3 was applied and followed by two rinses with distilled water. Samples were dissolved in 0.075 M nitric acid (HNO3) (500 μL) assisted by sonication for 25 mins.   6 Finally samples were centrifuged for 4 mins at 13400 rpm...

  11. Surface Water & Surface Drainage

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains boundaries for all surface water and surface drainage for the state of New Mexico. It is in a vector digital data structure digitized from a...

  12. Quality of groundwater and surface water, Wood River Valley, south-central Idaho, July and August 2012

    Science.gov (United States)

    Hopkins, Candice B.; Bartolino, James R.

    2013-01-01

    Residents and resource managers of the Wood River Valley of south-central Idaho are concerned about the effects that population growth might have on the quality of groundwater and surface water. As part of a multi-phase assessment of the groundwater resources in the study area, the U.S. Geological Survey evaluated the quality of water at 45 groundwater and 5 surface-water sites throughout the Wood River Valley during July and August 2012. Water samples were analyzed for field parameters (temperature, pH, specific conductance, dissolved oxygen, and alkalinity), major ions, boron, iron, manganese, nutrients, and Escherichia coli (E.coli) and total coliform bacteria. This study was conducted to determine baseline water quality throughout the Wood River Valley, with special emphasis on nutrient concentrations. Water quality in most samples collected did not exceed U.S. Environmental Protection Agency standards for drinking water. E. coli bacteria, used as indicators of water quality, were detected in all five surface-water samples and in two groundwater samples collected. Some analytes have aesthetic-based recommended drinking water standards; one groundwater sample exceeded recommended iron concentrations. Nitrate plus nitrite concentrations varied, but tended to be higher near population centers and in agricultural areas than in tributaries and less populated areas. These higher nitrate plus nitrite concentrations were not correlated with boron concentrations or the presence of bacteria, common indicators of sources of nutrients to water. None of the samples collected exceeded drinking-water standards for nitrate or nitrite. The concentration of total dissolved solids varied considerably in the waters sampled; however a calcium-magnesium-bicarbonate water type was dominant (43 out of 50 samples) in both the groundwater and surface water. Three constituents that may be influenced by anthropogenic activity (chloride, boron, and nitrate plus nitrite) deviate from this

  13. Hydrochemical assessments of surface Nile water and ground water in an industry area – South West Cairo

    Directory of Open Access Journals (Sweden)

    Mona El-Sayed

    2015-09-01

    The data obtained were used for mathematical calculations of some parameters such as sodium adsorption ratio (SAR, sodium percentage (Na%, and the suitability of water samples for drinking, domestic, and irrigation purposes was evaluated. The results indicate that most studied surface Nile water samples show excellent to good categories and are suitable for drinking and irrigation. Most studied ground water samples are not suitable for drinking and need treatment for irrigation; few samples are not suitable for any purpose because of pollution from different sources in this area.

  14. Spatial variability of surface-sediment porewater pH and related water-column characteristics in deep waters of the northern South China Sea

    Science.gov (United States)

    Shao, Changgao; Sui, Yi; Tang, Danling; Legendre, Louis

    2016-12-01

    This study analyzes the pH of surface-sediment porewater (i.e. 2-3 cm below the water-sediment interface), and concentrations of CaCO3 and organic carbon (OC) in 1192 sediment cores from the northern South China Sea, in water depths ranging from 137 to 3702 m. This is the first study in the literature to analyze the large-scale spatial variability of deep-water surface-sediment pH over a large ocean basin. The data showed strong spatial variations in pH. The lowest pH values (Pearl and Red Rivers. Moderately low pH values (generally 7.3-7.5) occurred in two other areas: a submarine canyon, where sediments originated partly from the Pearl River and correspond to a paleo-delta front during the last glacial period; and southwest of Taiwan Island, where waters are affected by the northern branch of the Kuroshio intrusion current (KIC) and runoff from Taiwan rivers. The surface sediments with the highest pH (⩾7.5, and up to 8.3) were located in a fourth area, which corresponded to the western branch of the KIC where sediments have been intensively eroded by bottom currents. The pH of surface-sediment porewater was significantly linearly related to water depth, bottom-water temperature, and CaCO3 concentration (p < 0.05 for the whole sampling area). This study shows that the pH of surface-sediment porewater can be sensitive to characteristics of the overlying water column, and suggests that it will respond to global warming as changes in surface-ocean temperature and pH progressively reach deeper waters.

  15. Ra-228, Ra-226, Pb-210 and Po-210 variations in the water columns and the surface water plankton in the Luzon Strait and northern South China Sea

    Science.gov (United States)

    Chung, Y.; Lin, C.; Wang, P.; Su, Y.

    2006-12-01

    Profiles of Ra-228, Ra-226, Pb-210 and Po-210 were measured in the Luzon Strait (LS) and northern South China Sea (SCS) areas to delineate the exchanges between the western Philippine Sea (WPS) and the northern SCS waters across the LS. Plankton samples were also collected for Po-210 and Pb-210 measurements to assess the balance between the Po-210 excess over Pb-210 in the plankton and the deficit in the surface water. Profiles of Ra-228 and Ra-226 seem to indicate the out flow of the SCS water below the salinity minimum and above around 1500m depth, below which the WPS water flows into the SCS through the LS above a sill depth of about 2600m. This is consistent with previous studies conducted in the area. All the Pb-210 profiles show a strong subsurface maximum with higher activity in the LS area. This maximum is in large excess over its parent, Ra-226 due to atmospheric input. Po-210 profiles generally follow the associated Pb-210 profiles but with lower activities, showing Po-210 deficiency. Po-210 is strongly enriched over Pb-210 in the plankton samples with an activity ratio generally over 10 and up to 40. Both nuclides in the plankton are higher in the LS area, a trend similar to the surface water. The Po-210 excess in the plankton can account for at least 70 percent of the surface water deficit, part of which may be removed by sinking particles.

  16. Seasonal Variation of Phytoplankton Assemblages Related to Surface Water Mass in the Eastern Part of the South Sea in Korea

    Directory of Open Access Journals (Sweden)

    Pung-Guk Jang

    2013-06-01

    Full Text Available We investigated the seasonal succession of phytoplankton assemblages in the eastern part of the South Sea of Korea in relation to surface water masses. The study areas are under the direct influence of the Tsushima Warm Current (TCW throughout the whole year, with its strength known to be seasonally variable. The region is also influenced by coastal waters (CW driven from the South Sea of Korea and East China Sea, particularly in summer, as indicated by low salinity in the surface water. Nutrient property of the TCW can reveals whether the origin of the TCW is the nutrient-rich Kuroshio Current or the oligotropic Taiwan Warm Current. Surface chlorophyll-a (Chl-a concentrations displayed a large seasonal variation for all stations, with high values found in spring and autumn and low values in summer and winter. At station M (offshore and P (intermediate location between M and R, Chl-a concentrations in October were higher than those in March, when spring bloom normally occurs. This may be related to deeper mixed layer depths in October. Diatoms dominated under conditions of high nutrient supply in which Chaetoceros spp. and Skeletonema costatum-like spp. were abundant. S. costatum-like spp. dominated at stations R (onshore station and P in December when there was greater nutrient supply, especially of phosphate. Flagellates and dinoflagellates dominated at all three stations after diatoms blooms. Dominant species were Scrippsiella trochoid in April and Ceratium furca in October at station R, and Gyrodinium spp. and Gymnodinium spp. at station M during summer, when the effect of the oligotropic Taiwan Warm Current and the oligotropic coastal water from East China Sea were strong. Redundancy analysis showed clear seasonal successions in the phytoplankton community and environmental conditions, in which both principal components 1 and 2 accounted for 69.6% of total variance. Our results suggested that environmental conditions seemed to be determined

  17. Science to support the understanding of south Texas surface-water and groundwater resources in a changing landscape

    Science.gov (United States)

    Ockerman, Darwin J.; Garcia, Travis J.; Opsahl, Stephen P.

    2012-01-01

    Against a backdrop of constant cycles of extreme hydrologic conditions ranging from oppressive droughts to life-threatening floods, the water-resource landscape of south Texas is undergoing constant change. Demands on water resources are increasing because of changes related to population growth, energy demands, agricultural practices, and other human-related activities. In south Texas, the Nueces, San Antonio, and Guadalupe River Basins cover approximately 50,000 square miles and include all or part of 45 counties. These stream systems transect the faulted and fractured carbonate rocks of the Edwards aquifer recharge zone and provide the largest sources of recharge to the aquifer. As the streams make their way to the Gulf of Mexico, they provide water for communities and ecosystems in south Texas and deliver water, sediment, and nutrients to the south Texas bays and estuaries.

  18. Disequilibria between 210Po and 210Pb in surface waters of the southern South China Sea and their implications

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Activities of the naturally occurring radionuclides, 210Pb and 210Po, were measured in both dissolved (0.45 μm) phases from surface waters of the southern South China Sea. The average activity of particulate 210Pb, 0.23 Bq/m3 (n=23), accounted for about 12% of the total 210Pb, which corresponds with values of open oceans. Particulate 210Po, with an average activity of 0.43 Bq/m3, accounted for about 40% of the total 210Po, which was much higher than those of open and eutrophic oceans. The residence times of total 210Po and 210Pb in surface waters estimated from an irreversible steady-state model were 0.82 a and 1.16 a, respectively. The consistently high fractionation factor calculated either by scavenging rate constants (5.42) or Kd values (6.69) suggested that a significant fractionation occurred between 210Po and 210Pb during their removal from solution to particles and that the two radionuclides had different biogeochemical cycling pathways in the oligotrophic South China Sea. Furthermore, our results indicated that there exist different fractionation mechanisms between 210Po and 210Pb in different marine environments: in eutrophic ocean, plankton detritus and fecal pellets are the main carrier of 210Po and 210Pb, by which 210Po and 210Pb have been scavenged and removed; while in oligotrophic ocean, microbes could become the main carrier of 210Po and fractionate 210Po and 210Pb significantly as a result of scarce plankton detritus and fecal pellets. These results suggest the use of 210Po to trace marine biogeochemical processes relating to microbial activities and the cycling of sulfur group elements (S, Se, Te and Po).

  19. Similarity in microbial amino acid uptake in surface waters of the North and South Atlantic (sub-)tropical gyres

    Science.gov (United States)

    Hill, Polly G.; Mary, Isabelle; Purdie, Duncan A.; Zubkov, Mikhail V.

    2011-12-01

    The Earth’s most extensive biomes - the oceanic subtropical gyres - are considered to be expanding with current surface ocean warming. Although it is well established that microbial communities control gyre biogeochemistry, comparisons of their metabolic activities between gyres are limited. In order to estimate metabolic activities including production of microbial communities, the uptake rates of amino acids leucine, methionine and tyrosine at ambient concentrations were estimated in surface waters of the Atlantic Ocean using radioisotopically labelled tracers. Data were acquired during six research cruises covering main oceanic provinces herein termed: North and South Atlantic Gyres, Bermuda Atlantic Time-series Study site (BATS), Equatorial region, and Mauritanian Upwelling (off Cape Blanc). Data were divided between provinces, the extents of which were identified by ocean colour data, in order to achieve provincial mean uptake rates. Leucine and methionine uptake rates did not differ between sampling periods, and were comparable between the North and South subtropical gyres. Furthermore, variation in uptake rates measured throughout the two oligotrophic gyres, where sampling covered ∼4 × 10 6 km 2, was considerably lower than that measured within the Mauritanian Upwelling and Equatorial regions, and even at the BATS site. Tyrosine was generally the slowest of the amino acids to be taken up, however, it was assimilated faster than methionine within the Mauritanian Upwelling region. Thus, we propose that one value for leucine (12.6 ± 3.2 pmol L -1 h -1) and methionine (10.0 ± 3.3 pmol L -1 h -1) uptake could be applied to the oligotrophic subtropical gyres of the Atlantic Ocean. However, with the significantly lower uptake rates observed at the BATS site, we would not advise extrapolation to the Sargasso Sea.

  20. Water-column cooling and sea surface salinity increase in the upwelling region off central-south Chile driven by a poleward displacement of the South Pacific High

    Science.gov (United States)

    Schneider, Wolfgang; Donoso, David; Garcés-Vargas, José; Escribano, Rubén

    2017-02-01

    Here we present results of direct observations of seawater temperature and salinity over the continental shelf off central-south Chile that shows an unprecedented cooling of the entire water column and an increase in upper layer salinity during 2002 to 2013. We provide evidence that this phenomenon is related to the intensification but mostly to a recent southward displacement of the South Pacific High over the same period, from 2007 on. This in turn has accelerated alongshore, equatorward, subtropical coastal upwelling favorable winds, particularly during winter, injecting colder water from below into the upper water column. Consequently, the environmental conditions on the shelf off central-south Chile shifted from a warmer (fresher) to a cooler (saltier) phase; water column temperature dropped from 11.7 °C (2003-2006) to 11.3 °C (2007-2012) and upper layer salinity rose by 0.25; water column stratification gradually decreased. The biological impacts of such abrupt cooling are apparently already happening in this coastal ecosystem, as recent evidence shows substantial changes in the plankton community and negative trends in zooplankton biomass over the same period.

  1. Spatial variations in archaeal lipids of surface water and core-top sediments in the South china sea and their implications for paleoclimate studies.

    Science.gov (United States)

    Wei, Yuli; Wang, Jinxiang; Liu, Jie; Dong, Liang; Li, Li; Wang, Hui; Wang, Peng; Zhao, Meixun; Zhang, Chuanlun L

    2011-11-01

    The South China Sea (SCS) is the largest marginal sea of the western Pacific Ocean, yet little is known about archaeal distributions and TEX₈₆-based temperatures in this unique oceanic setting. Here we report findings of abundances in both core lipids (CL) and intact polar lipids (IPL) of Archaea from surface water (CL only) and core-top sediments from different regions of the SCS. TEX₈₆-derived temperatures were also calculated for these samples. The surface water had extremely low abundances of CL (average of 0.05 ± 0.13 ng/liter; n = 75), with higher values present in regions where upwelling is known to occur. The core-top sediments had CL values of 0.1 to 0.9 μg/g, which are on the low end of CL concentrations reported for other marine sediments and may reflect the oligotrophic nature of the open SCS. The IPL of Archaea accounted for 6 to 36.4% of total lipids (CL plus IPL), indicating that the majority of archaeal lipids in core-top sediments were derived from nonliving cells. The TEX₈₆-based temperatures of surface water were overall lower than satellite-based sea surface temperatures or CTD-measured in situ temperatures. The core-top sediment samples, however, had TEX₈₆ temperatures very close to the mean annual sea surface temperatures, except for samples with water depths of less than 100 m. Our results demonstrated low and heterogeneous distributions of archaeal lipids in surface water and core-top sediments of the SCS, which may reflect local or regional differences in productivity of Archaea. While TEX₈₆-based temperatures for core-top marine sediments at deep water depths (>100 m) generally reflected mean annual sea surface temperatures, TEX₈₆ temperatures in surface water varied basin wide and underestimated sea surface temperatures in most locations for the season when surface water samples were collected.

  2. Isolation of Environmental Bacteria from Surface and Drinking Water in Mafikeng, South Africa, and Characterization Using Their Antibiotic Resistance Profiles

    Directory of Open Access Journals (Sweden)

    Suma George Mulamattathil

    2014-01-01

    Full Text Available The aim of this study was to isolate and identify environmental bacteria from various raw water sources as well as the drinking water distributions system in Mafikeng, South Africa, and to determine their antibiotic resistance profiles. Water samples from five different sites (raw and drinking water were analysed for the presence of faecal indicator bacteria as well as Aeromonas and Pseudomonas species. Faecal and total coliforms were detected in summer in the treated water samples from the Modimola dam and in the mixed water samples, with Pseudomonas spp. being the most prevalent organism. The most prevalent multiple antibiotic resistance phenotype observed was KF-AP-C-E-OT-K-TM-A. All organisms tested were resistant to erythromycin, trimethoprim, and amoxicillin. All isolates were susceptible to ciprofloxacin and faecal coliforms and Pseudomonas spp. to neomycin and streptomycin. Cluster analysis based on inhibition zone diameter data suggests that the isolates had similar chemical exposure histories. Isolates were identified using gyrB, toxA, ecfX, aerA, and hylH gene fragments and gyrB, ecfX, and hylH fragments were amplified. These results demonstrate that (i the drinking water from Mafikeng contains various bacterial species and at times faecal and total coliforms. (ii The various bacteria are resistant to various classes of antibiotics.

  3. Effects of impervious cover on the surface water quality and aquatic ecosystem of the Kyeongan stream in South Korea.

    Science.gov (United States)

    Lee, Bum-Yeon; Park, Shin-Jeong; Paule, Ma Cristina; Jun, Woosong; Lee, Chang-Hee

    2012-08-01

    The extent of impervious cover in a watershed has been linked to the quality of an urban aquatic environment. The Kyeongan watershed in South Korea was investigated to evaluate the relationship between the total impervious area (TIA) and the aquatic ecosystem of the watershed, including water quality and aquatic life using a relatively high-resolution (0.4 m) image. The TIA was found to be approximately 12% of the watershed, which indicates that the quality of its environment was being adversely affected by it. For water quality, Pearson correlation analyses showed that all water quality parameters studied were found to be positively correlated with TIA at p water quality. Some water quality parameters, such as nitrite (NO2-), total phosphorus, and phosphate (PO4(3-)) were highly affected by discharges from wastewater treatment plants. Water quality data suggest that TIA could be used to predict the water quality of streams. For ecological parameters, the diatom index for organic pollution and trophic diatom index were found to be highly correlated with TIA, whereas physical habitat and benthic macroinvertebrates were poorly correlated with TIA. However, the results indicate that the extent of impervious cover can be a useful indicator for predicting the status of specific ecosystem of streams.

  4. Chemical quality of surface waters, and sedimentation in the Grand River drainage basin, North and South Dakota

    Science.gov (United States)

    Hembree, Charles Herbert; Krieger, Robert A.; Jordan, Paul Robert

    1964-01-01

    An investigation of the chemical quality of surface waters and of the sedimentation in the Grand River drainage basin by the U.S. Geological Survey began in 1946. The chemical quality of the water was studied to obtain information on the nature and amounts of dissolved solids in the streams and on the suitability of the water for domestic, industrial, and irrigation uses. Sedimentation was studied to determine the quantity of sediment that is transported by the streams, the particle sizes of the sediment, and the probable specific weight of the sediment when deposited in a reservoir.

  5. Antibiotic resistance and community analysis of surface and subsurface drainage waters in the South Fork Iowa River watershed

    Science.gov (United States)

    The Midwest is a center for swine production leading to application of swine manure onto lands that have artificial subsurface drainage. Previous reports have indicated elevated levels of antibiotic resistance genes (ARGs) in surface water and groundwater around confined animal feeding operations w...

  6. Antibiotic resistance and community analysis of surface and subsurface drainage waters in the South Fork Iowa River watershed

    Science.gov (United States)

    The Midwest is a center for swine production leading to application of swine manure onto lands that have artificial subsurface drainage. Previous reports have indicated elevated levels of antibiotic resistance genes (ARGs) in surface water and groundwater around confined animal feeding operations wh...

  7. Distribution and bioconcentration of endocrine disrupting chemicals in surface water and fish bile of the Pearl River Delta, South China.

    Science.gov (United States)

    Yang, Juan; Li, Haiyan; Ran, Yong; Chan, Kingming

    2014-07-01

    The distribution and bioconcentration of endocrine disrupting chemicals (EDCs) in water, algae, and wild carp bile of the Pearl River Delta (PRD), South China were investigated. 4-tert octylphenol (OP), 4-nonylphenol (NP), and bisphenol A (BPA) (unit, ng L(-1)) in water were in the ranges of 1-14, 117-865, and 4-377, those (ng g(-1) dry weight) in algae were in the ranges of 2-13, 53-282, and 16-94, and those (ng g(-1)) in carp bile were in the ranges of 14-39, 950-4648, 70-1020, respectively. Estrone (E1) and 17α-ethinylestradiol (EE2) in water ranged from water. The EEQs in carp bile were significantly related to those in water, illustrating that occurrence of EDCs in carp bile can reflect that in ambient water in the PRD region. The bioconcentration factors (BCF, L kg(-1)) of OP, NP, BPA, and E1 in algae were in the ranges of 482-7251, 131-740, 2846-12979, and undetectable, respectively, and those in carp bile were in the ranges of 1500-12960, 1648-11137, 3583-14178, and 13208-39623, respectively. The phenolic EDCs can be accumulated by wild carp bile and algae in the investigated aquatic ecosystems, which is also affected by the degree of the eutrophication. This study for the first time reported EDCs in carp bile and algae collected from the PRD, China.

  8. South Asian summer monsoon variability during the last ˜54 kyrs inferred from surface water salinity and river runoff proxies

    Science.gov (United States)

    Gebregiorgis, D.; Hathorne, E. C.; Sijinkumar, A. V.; Nath, B. Nagender; Nürnberg, D.; Frank, M.

    2016-04-01

    The past variability of the South Asian Monsoon is mostly known from records of wind strength over the Arabian Sea while high-resolution paleorecords from regions of strong monsoon precipitation are still lacking. Here, we present records of past monsoon variability obtained from sediment core SK 168/GC-1, which was collected at the Alcock Seamount complex in the Andaman Sea. We utilize the ecological habitats of different planktic foraminiferal species to reconstruct freshwater-induced stratification based on paired Mg/Ca and δ18O analyses and to estimate seawater δ18O (δ18Osw). The difference between surface and thermocline temperatures (ΔT) and δ18Osw (Δδ18Osw) is used to investigate changes in upper ocean stratification. Additionally, Ba/Ca in G. sacculifer tests is used as a direct proxy for riverine runoff and sea surface salinity (SSS) changes related to monsoon precipitation on land. Our Δδ18Osw time series reveals that upper ocean salinity stratification did not change significantly throughout the last glacial suggesting little influence of NH insolation changes. The strongest increase in temperature gradients between the mixed layer and the thermocline is recorded for the mid-Holocene and indicate the presence of a significantly shallower thermocline. In line with previous work, the δ18Osw and Ba/Ca records demonstrate that monsoon climate during the LGM was characterized by a significantly weaker southwest monsoon circulation and strongly reduced runoff. Based on our data the South Asian Summer Monsoon (SAM) over the Irrawaddyy strengthened gradually after the LGM beginning at ∼18 ka. This is some 3 kyrs before an increase of the Ba/Ca record from the Arabian Sea and indicates that South Asian Monsoon climate dynamics are more complex than the simple N-S displacement of the ITCZ as generally described for other regions. Minimum δ18Osw values recorded during the mid-Holocene are in phase with Ba/Ca marking a stronger monsoon precipitation

  9. Assessment of Trace Metals Contamination of Surface Water and Sediment: A Case Study of Mvudi River, South Africa

    Directory of Open Access Journals (Sweden)

    Joshua N. Edokpayi

    2016-02-01

    Full Text Available Trace metals contamination of rivers and sediments remains a global threat to biodiversity and humans. This study was carried out to assess the variation pattern in trace metals contamination in Mvudi River water and sediments for the period of January–June 2014. Metal concentrations were analyzed using an inductively-coupled plasma optical emission spectrometer after nitric acid digestion. A compliance study for the water samples was performed using the guidelines of the Department of Water Affairs and Forestry (DWAF of South Africa and the World Health Organization (WHO. The National Oceanic and Atmospheric Administration (NOAA sediment quality guidelines for marine and estuarine sediments and the Canadian Council of Ministers of the Environment sediment guidelines (CCME for freshwater sediments were used to determine the possible toxic effects of the metals on aquatic organisms. pH (7.2–7.7 and conductivity (10.5–16.1 mS/m values complied with DWAF and WHO standards for domestic water use. Turbidity values in nephelometric turbidity units (NTU were in the range of 1.9–429 and exceeded the guideline values. The monthly average levels of trace metals in the water and sediments of Mvudi River were in the range of: Al (1.01–9.644 mg/L and 4296–5557 mg/kg, Cd (0.0003–0.002 mg/L and from below the detection limit to 2.19 mg/kg, Cr (0.015–0.357 mg/L and 44.23–149.52 mg/kg, Cu (0.024–0.185 mg/L and 13.22–1027 mg/kg, Fe (0.702–2.645 mg/L and 3840–6982 mg/kg, Mn (0.081–0.521 mg/L and 279–1638 mg/kg, Pb (0.002–0.042 mg/L and 1.775-4.157 mg/kg and Zn (0.031–0.261 mg/L and 14.481–39.88 mg/kg. The average concentrations of Al, Cr, Fe, Mn and Pb in the water samples exceeded the recommended guidelines of DWAF and WHO for domestic water use. High concentrations of Al and Fe were determined in the sediment samples. Generally, the concentrations of Cd, Cr and Cu in the sediments exceeded the corresponding effect range low

  10. Hydrogeologic framework and groundwater/surface-water interactions of the South Fork Nooksack River Basin, northwestern Washington

    Science.gov (United States)

    Gendaszek, Andrew S.

    2014-01-01

    A hydrogeologic framework of the South Fork (SF) Nooksack River Basin in northwestern Washington was developed and hydrologic data were collected to characterize the groundwater-flow system and its interaction with surface‑water features. In addition to domestic, agricultural, and commercial uses of groundwater within the SF Nooksack River Basin, groundwater has the potential to provide ecological benefits by maintaining late-summer streamflows and buffering stream temperatures. Cold-water refugia, created and maintained in part by groundwater, have been identified by water-resource managers as key elements to restore the health and viability of threatened salmonids in the SF Nooksack River. The SF Nooksack River drains a 183-square mile area of the North Cascades and the Puget Lowland underlain by unconsolidated glacial and alluvial sediments deposited over older sedimentary, metamorphic, and igneous bedrock. The primary aquifer that interacts with the SF Nooksack River was mapped within unconsolidated glacial outwash and alluvial sediment. The lower extent of this unit is bounded by bedrock and fine-grained, poorly sorted unconsolidated glaciomarine and glaciolacustrine sediments. In places, these deposits overlie and confine an aquifer within older glacial sediments. The extent and thickness of the hydrogeologic units were assembled from mapped geologic units and lithostratigraphic logs of field-inventoried wells. Generalized groundwater-flow directions within the surficial aquifer were interpreted from groundwater levels measured in August 2012; and groundwater seepage gains and losses to the SF Nooksack River were calculated from synoptic streamflow measurements made in the SF Nooksack River and its tributaries in September 2012. A subset of the field-inventoried wells was measured at a monthly interval to determine seasonal fluctuations in groundwater levels during water year 2013. Taken together, these data provide the foundation for a future groundwater

  11. Nitrate pollution and its transfer in surface water and groundwater in irrigated areas: a case study of the Piedmont of South Taihang Mountains, China.

    Science.gov (United States)

    Li, Jing; Li, Fadong; Liu, Qiang; Suzuki, Yoshimi

    2014-12-01

    Irrigation projects have diverted water from the lower reaches of the Yellow River in China for more than 50 years and are unique in the world. This study investigated the effect of irrigation practices on the transfer and regional migration mechanisms of nitrate (NO3(-)) in surface water and groundwater in a Yellow River alluvial fan. Hydrochemical indices (EC, pH, Na(+), K(+), Mg(2+), Ca(2+), Cl(-), SO4(2-), and HCO(3-)) and stable isotopic composition (δ18O and δD) were determined for samples. Correlation analysis and principal component analysis (PCA) were performed to identify the sources of water constituents. Kriging was employed to simulate the spatial diffusion of NO3(-) and stable isotopes. Our results demonstrated that the groundwater exhibited more complex saline conditions than the surface water, likely resulting from alkaline conditions and lixiviation. NO3(-) was detected in all samples, 87.0% of which were influenced by anthropogenic activity. The NO3(-) pollution in groundwater was more serious than the common groundwater irrigation areas in the North China Plain (NCP), and was also slightly higher than that in surface water in the study area, but this was not statistically significant (p > 0.05). In addition, the groundwater sites with higher NO3(-) concentrations did not overlap with the spatial distribution of fertilizer consumption, especially in the central and western parts of the study area. NO3(-) distributions along the hydrogeological cross-sections were related to the groundwater flow system. Hydrochemical and environmental isotopic evidences indicate that surface water-groundwater interactions influence the spatial distribution of NO3(-) in the Piedmont of South Taihang Mountains.

  12. A diagnosis of sub-surface water table dynamics in low hydraulic conductivity soils in the sugar cane fields of Pongola, South Africa

    Science.gov (United States)

    Malota, Mphatso; Senzanje, Aidan

    2016-04-01

    Water and land are the two natural resources restraining crop production in South Africa. With the increasing demand for food, emphasis has shifted from the sole reliance on rain fed crop production, to irrigation. The deterioration in irrigation water quality from surface water sources is, however, posing a big challenge to the sustainability of irrigated crop production. This is because more water is required for leaching, resulting in shallow water tables in agricultural lands. The installation of well designed subsurface drainage systems alone is not enough; the provision of timely maintenance is also necessary. In this study, the extent and severity of problems as a consequence of shallow water tables and their possible causes were investigated at three sugarcane fields in Pongola, South Africa, having low hydraulic conductivity soils. Also investigated were soil salinity levels and the temporal variation in the salinity of the irrigation water. A water table map of a 32 ha sugarcane field was generated, using observed water table depth (WTD) data from 36 piezometers monitored from September 2011 to February 2012. Out of the total 32 ha under cultivation, 12% was found to be affected by shallow WTDs of less than the 1.0 m design WTD. The inability of natural drainage to cope with subsurface drainage needs and the poor maintenance of subsurface drainage systems contributed to the shallow water tables in the area. Furthermore, the currently adopted drainage design criteria also proved unsatisfactory with mean observed water table depth and drainage discharge (DD) of 20% and 50%, respectively, less than their respective design levels. The salinity of the irrigation water was, on average, 32% higher than threshold tolerance level of sugarcane. The root zone soil salinity levels at the three study sites were greater than the 1.7 dS m-1 threshold for sugar cane. The subsurface drainage design criteria adopted at the site needs to be revisited by ensuring that the

  13. Impact of water depth on the distribution of iGDGTs in the surface sediments from the northern South China Sea: applicability of TEX86 in marginal seas

    Science.gov (United States)

    Chen, Jiali; Hu, Pengju; Li, Xing; Yang, Yang; Song, Jinming; Li, Xuegang; Yuan, Huamao; Li, Ning; Lü, Xiaoxia

    2017-01-01

    The TEX{86/H} paleothermometer on the base of isoprenoid glycerol dialkyl glycerol tetraethers (iGDGTs) has been widely applied to various marine settings to reconstruct past sea surface temperatures (SSTs). However, it remains uncertain how well this proxy reconstructs SSTs in marginal seas. In this study, we analyze the environmental factors governing distribution of iGDGTs in surface sediments to assess the applicability of TEX{86/H} paleothermometer in the South China Sea (SCS). Individual iGDGT concentrations increase gradually eastwards. Redundancy analysis based on the relative abundance of an individual iGDGT compound and environmental parameters suggests that water depth is the most influential factor to the distribution of iGDGTs, because thaumarchaeota communities are water-depth dependent. Interestingly, the SST difference (ΔT) between TEX{86/H} derived temperature and remote-sensing SST is less than 1°C in sediments with water depth>200 m, indicating that TEX{86/H} was the robust proxy to trace the paleo-SST in the region if water depth is greater than 200 m.

  14. Characterization of surface-water quality based on real-time monitoring and regression analysis, Quivira National Wildlife Refuge, south-central Kansas, December 1998 through June 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Because of the considerable wildlife benefits offered by the Quivira National Wildlife Refuge in south-central Kansas, there is a desire to ensure suitable water...

  15. Reconstruction of surface ocean water pCO2(aq) in Nansha area, the South China Sea during the last 30 ka

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The reconstruction of pCO2 in the tropic ocean is one of the most important issues to understand global climatic changes. In this study, the high-resolution stratigraphic analysis of core 17962 was conducted, which is located in the southern South China Sea (SCS). The contents of sedimentary organic matter, the stable carbon isotopic composition of sedimentary organic matter, and the δ13C values of black carbon and terrigenous n-alkanes were determined. And the δ13Cwc value of carbon derived from aquatic was calculated. On the basis of δ13Corg-pCO2 equation proposed by Popp et al. (1989), we estimated the pCO2 in the Nansha area, SCS, since the last glaciation using δ13Cwc instead of δ13Corg. The results show that the average pCO2 was estimated at 240 ppmV during the last glaciation, and at 320 ppmV in the Holocene. A comparison of surface sea pCO2 with the atmosphere CO2 recorded in the Vostok ice core, indicates that CO2 in surface water of the southern SCS could emit into atmosphere during the last 30 ka.

  16. Surface-water surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Saldi, K.A.; Dirkes, R.L.; Blanton, M.L.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the Surface water on and near the Hanford Site is monitored to determine the potential effects of Hanford operations. Surface water at Hanford includes the Columbia River, riverbank springs, ponds located on the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site, and offsite water systems directly east and across the Columbia River from the Hanford Site. Columbia River sediments are also included in this discussion. Tables 5.3.1 and 5.3.2 summarize the sampling locations, sample types, sampling frequencies, and sample analyses included in surface-water surveillance activities during 1994. Sample locations are also identified in Figure 5.3.1. This section describes the surveillance effort and summarizes the results for these aquatic environments. Detailed analytical results are reported by Bisping (1995).

  17. Occurrence and distribution of selected heavy metals in the surface sediments of South Brittany coastal waters: An assessment using pollution indicators

    Science.gov (United States)

    Ong, M. C.; Menier, D.; Noor Azhar, M. S.; Dupont, V.; Révillon, S.

    2012-04-01

    In order to avoid the pollution of heavy metals in South Brittany water, it is necessary to establish the data and understand the mechanisms influencing the distribution of heavy metals of the area. One of the aims of this work was to assess heavy metals contamination in Gulf of Morbihan and Quiberon Bay. Another aim was to use interpolation surfaces per metals to assess the contamination separately per metal. A total of 196 bottom sediment samples were collected from the coastal waters in order to determine the spatial concentration of Cr, Mn, Co, Cu, Zn, Cd and Pb by Inductively Coupled Plasma Mass Spectrometry (ICPMS) after acid digestion. The average heavy metal concentrations are ranked as follows: Mn>Zn>Cr>Pb>Cu>Cu>Cd. In the gulf, metal enrichments observed compared to the bay environment may due river run-off from three major river (Auray, Le Marle and Novalo rivers) which carried municipal waste and maritime activities along the coastal area within the gulf. Beside those factors, the natural factors such as the sheltered basin morphology itself, fine sediment and low hydrodynamic regime which favour the in situ accumulation of pollutants. The level of pollution levels attributed to heavy metals was evaluated using several pollution indicators in order to determine anthropogenically derived sediment contamination. Comparison to sediment quality guidelines (SQGs), enrichment factors (EFs), index of geoaccumulation (Igeo) and contamination factors (CF) based on reference element and background value to compensate for the influence of the natural variability in sediment mineralogy and to assess whether the concentration observed in surface sediment represent background and contaminated levels and visualize using ArcGIS software. These analyses validated that the bottom sediment only enriched in Pb and the other metals in most sample are not due to artificial contamination. Overall, geochemistry of the samples show the effect of both natural and anthropogenic

  18. Surface Water in Hawaii

    Science.gov (United States)

    Oki, Delwyn S.

    2003-01-01

    Surface water in Hawaii is a valued resource as well as a potential threat to human lives and property. The surface-water resources of Hawaii are of significant economic, ecologic, cultural, and aesthetic importance. Streams supply more than 50 percent of the irrigation water in Hawaii, and although streams supply only a few percent of the drinking water statewide, surface water is the main source of drinking water in some places. Streams also are a source of hydroelectric power, provide important riparian and instream habitats for many unique native species, support traditional and customary Hawaiian gathering rights and the practice of taro cultivation, and possess valued aesthetic qualities. Streams affect the physical, chemical, and aesthetic quality of receiving waters, such as estuaries, bays, and nearshore waters, which are critical to the tourism-based economy of the islands. Streams in Hawaii pose a danger because of their flashy nature; a stream's stage, or water level, can rise several feet in less than an hour during periods of intense rainfall. Streams in Hawaii are flashy because rainfall is intense, drainage basins are small, basins and streams are steep, and channel storage is limited. Streamflow generated during periods of heavy rainfall has led to loss of property and human lives in Hawaii. Most Hawaiian streams originate in the mountainous interiors of the islands and terminate at the coast. Streams are significant sculptors of the Hawaiian landscape because of the erosive power of the water they convey. In geologically young areas, such as much of the southern part of the island of Hawaii, well-defined stream channels have not developed because the permeability of the surface rocks generally is so high that rainfall infiltrates before flowing for significant distances on the surface. In geologically older areas that have received significant rainfall, streams and mass wasting have carved out large valleys.

  19. Seasonal exposures to triazine and other pesticides in surface waters in the western Highveld corn-production region in South Africa

    Science.gov (United States)

    Du Preez, L.H.; Jansen Van Rensburg, P.J.; Jooste, A.M.; Carr, J.A.; Giesy, J.P.; Gross, T.S.; Kendall, R.J.; Smith, E.E.; Van Der Kraak, G.; Solomon, K.R.

    2005-01-01

    The objective of this study was to characterize concentrations of atrazine, terbuthylazine, and other pesticides in amphibian habitats in surface waters of a corn-production area of the western Highveld region (North-West Province) of South Africa. The study was conducted from November 2001 to June 2002, coinciding with the corn-production season. Pesticide residues were measured at regular intervals in surface water from eight ponds, three in a non-corn-growing area (NCGA) and five within the corn-growing area (CGA). Measured atrazine concentrations differed significantly among sites and between samples. In the five CGA sites, the maximum atrazine concentrations measured during the study ranged from 1.2 to 9.3 ??g/L. Although no atrazine was recorded as being applied in the catchment of the three NCGA sites, maximum concentrations from 0.39 to 0.84 ??g/L were measured during the study, possibly as a result of atmospheric transport. Maximum measured concentrations of terbuthylazine ranged from 1.22 to 2.1 ??g/L in the NCGA sites and from 1.04 to 4.1 ??g/L in the CGA sites. The source of terbuthylazine in the NCGA sites may have been in use other than in corn. The triazine degradation products, deisopropylatrazine (DIA) and deethylatrazine (DEA) and diaminochlorotriazine (DACT) were also found in water from both the CGA and NCGA sites. Concentrations of DIA were ??? 1 ??g/L throughout the season, while DEA concentrations were mostly 2 ??g/L in some locations. Concentrations of DACT were highly variable (LOD to 8 ??g/L) both before and after planting and application, suggesting that they resulted from historical use of triazines in the area. Other herbicides such as simazine and acetochlor were only detected infrequently and pesticides such as S-metolachlor, cypermethrin, monocrotophos, and terbuphos, known to be used in the CGA, were not detected in any of the samples. Because of dilution by higher than normal rainfall in the study period, these concentrations may

  20. Toxic substances in surface waters and sediments--A study to assess the effects of arsenic-contaminated alluvial sediment in Whitewood Creek, South Dakota

    Science.gov (United States)

    Kuwabara, James S.; Fuller, Christopher C.

    2003-01-01

    Field measurements and bioassay experiments were done to investigate the effects of arsenic and phosphorus interactions on sorption of these solutes by the benthic flora (periphyton and submerged macrophytes) in Whitewood Creek, a stream in western South Dakota. Short-term (24-hour) sorption experiments were used to determine arsenic transport characteristics for algae (first-order rate constants for solute sorption, biomass, and accumulation factors) collected in the creek along a transect beginning upstream from a mine discharge point and downgradient through a 57-kilometer reach. Temporal changes in biomass differed significantly between and within sampling sites. Arsenic concentrations in plant tissue increased with distance downstream, but temporal changes in concentrations in tissues differed considerably from site to site. Cultures of Achnanthes minutissima (Bacillariophyceae) and Stichococcus sp. (Chlorophyceae) were isolated from four sites along a longitudinal concentration gradient of dissolved arsenic within the study reach and were maintained at ambient solute concentrations. Arsenic accumulation factors and sorption-rate constants for these isolates were determined as a function of dissolved arsenate and orthophosphate. Cell surfaces of algal isolates exhibited preferential orthophosphate sorption over arsenate. Initial sorption of both arsenate and orthophosphate followed first-order mass transfer for each culturing condition. Although sorption-rate constants increased slightly with increased dissolved-arsenate concentration, algae, isolated from a site with elevated dissolved arsenic in the stream channel, had a significantly slower rate of arsenic sorption compared with the same species isolated from an uncontaminated site upstream. In diel studies, amplitudes of the pH cycles increased with measured biomass except at a site immediately downstream from water-treatment-plant discharge. Inorganic pentavalent arsenic dominated arsenic speciation at

  1. Microscopic isolation and characterization of free living amoebae (FLA from surface water sources.in Birjand, the capital city of the South Khorasan

    Directory of Open Access Journals (Sweden)

    Mahmoodreza Behravan

    2015-07-01

    Conclusion: The results indicated that a significant percentage of surface water sources in Birjand city was contaminated with Acanthamoeba spp. It is necessary for physicians, therefore, to take into account the diseases caused by these infectious agents. Besides, local regional health professionals should take into consideration the potential role of surface stagnant water sources in transferring these infectious agents. Placing warning signs in areas contaminated with these infectious agents seems a useful measure.

  2. Drought to flood: a comparative assessment of four parallel surface water treatments during the 2010-2012 inflows to the Murray-Darling Basin, South Australia.

    Science.gov (United States)

    Braun, Kalan; Fabris, Rolando; Morran, Jim; Ho, Lionel; Drikas, Mary

    2014-08-01

    Four treatment processes; conventional coagulation, magnetic ion exchange (MIEX)/coagulation, with and without granular activated carbon (GAC), and membrane treatment combining microfiltration (MF) and nanofiltration (NF), were operated in parallel using the same source water from the Murray-Darling basin in South Australia. During the two year study, high levels of natural organic matter and turbidity arising from floods affecting the Murray-Darling basin in 2010-2012 challenged the four processes. The comparative study indicated that all four processes could effectively meet basic water quality guidelines of turbidity and colour despite challenging source water quality but that the more advanced treatments improved overall organic and bacterial removal. Interestingly, the high organics and turbidity arising from the floods resulted in improved treatment efficiency for all treatments incorporating coagulation to the extent that, despite flood conditions, treated water quality could remain comparatively constant provided that the process was operated and optimised effectively.

  3. Water on graphene surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gordillo, M C [Departamento de Sistemas Fisicos, Quimicos y Naturales, Facultad de Ciencias Experimentales, Universidad Pablo de Olavide, Carretera de Utrera, km 1, E-41013 Sevilla (Spain); Marti, J, E-mail: cgorbar@upo.e, E-mail: jordi.marti@upc.ed [Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, B4-B5 Campus Nord, E-08034 Barcelona, Catalonia (Spain)

    2010-07-21

    In this paper, we summarize the main results obtained in our group about the behavior of water confined inside or close to different graphene surfaces by means of molecular dynamics simulations. These include the inside and outside of carbon nanotubes, and the confinement inside a slit pore or a single graphene sheet. We paid special attention to some thermodynamical (binding energies), structural (hydrogen-bond distributions) and dynamic (infrared spectra) properties, and their comparison to their bulk counterparts.

  4. Quantifying green water flows for improved Integrated Land and Water Resource Management under the National Water Act of South Africa: A review on hydrological research in South Africa.

    Science.gov (United States)

    Jarmain, C.; Everson, C. S.; Gush, M. B.; Clulow, A. D.

    2009-09-01

    The contribution of hydrological research in South Africa in quantifying green water flows for improved Integrated Land and Water Resources Management is reviewed. Green water refers to water losses from land surfaces through transpiration (seen as a productive use) and evaporation from bare soil (seen as a non-productive use). In contrast, blue water flows refer to streamflow (surface water) and groundwater / aquifer recharge. Over the past 20 years, a number of methods have been used to quantify the green water and blue water flows. These include micrometeorological techniques (e.g. Bowen ratio energy balance, eddy covariance, surface renewal, scintillometry, lysimetry), field scale models (e.g. SWB, SWAP), catchment scale hydrological models (e.g. ACRU, SWAT) and more recently remote sensing based models (e.g. SEBAL, SEBS). The National Water Act of South Africa of 1998 requires that water resources are managed, protected and used (developed, conserved and controlled) in an equitable way which is beneficial to the public. The quantification of green water flows in catchments under different land uses has been pivotal in (a) regulating streamflow reduction activities (e.g. forestry) and the management of alien invasive plants, (b) protecting riparian and wetland areas through the provision of an ecological reserve, (c) assessing and improving the water use efficiency of irrigated pastures, fruit tree orchards and vineyards, (d) quantifying the potential impact of future land uses like bio-fuels (e.g. Jatropha) on water resources, (e) quantifying water losses from open water bodies, and (f) investigating "biological” mitigation measures to reduce the impact of polluted water resources as a result of various industries (e.g. mining). This paper therefore captures the evolution of measurement techniques applied across South Africa, the impact these results have had on water use and water use efficiency and the extent to which it supported the National Water Act of

  5. Long Term Ecological Research (LTER) Daily Estuarine Surface Water Nutrient and Water Quality, Suspended Sediment, and Chlorophyll a Data for the North Inlet Estuary, Georgetown, South Carolina: 1978-1993

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — A one 1000 ml (one Liter) water sample was collected daily (at approximately 1000 hrs EST - but see note below in section 1.2.3 Supplemental Information) at a depth...

  6. Sustaining dry surfaces under water

    DEFF Research Database (Denmark)

    Jones, Paul R.; Hao, Xiuqing; Cruz-Chu, Eduardo R.

    2015-01-01

    Rough surfaces immersed under water remain practically dry if the liquid-solid contact is on roughness peaks, while the roughness valleys are filled with gas. Mechanisms that prevent water from invading the valleys are well studied. However, to remain practically dry under water, additional...... mechanisms need consideration. This is because trapped gas (e.g. air) in the roughness valleys can dissolve into the water pool, leading to invasion. Additionally, water vapor can also occupy the roughness valleys of immersed surfaces. If water vapor condenses, that too leads to invasion. These effects have...... not been investigated, and are critically important to maintain surfaces dry under water.In this work, we identify the critical roughness scale, below which it is possible to sustain the vapor phase of water and/or trapped gases in roughness valleys – thus keeping the immersed surface dry. Theoretical...

  7. Sustaining dry surfaces under water

    Science.gov (United States)

    Jones, Paul R.; Hao, Xiuqing; Cruz-Chu, Eduardo R.; Rykaczewski, Konrad; Nandy, Krishanu; Schutzius, Thomas M.; Varanasi, Kripa K.; Megaridis, Constantine M.; Walther, Jens H.; Koumoutsakos, Petros; Espinosa, Horacio D.; Patankar, Neelesh A.

    2015-08-01

    Rough surfaces immersed under water remain practically dry if the liquid-solid contact is on roughness peaks, while the roughness valleys are filled with gas. Mechanisms that prevent water from invading the valleys are well studied. However, to remain practically dry under water, additional mechanisms need consideration. This is because trapped gas (e.g. air) in the roughness valleys can dissolve into the water pool, leading to invasion. Additionally, water vapor can also occupy the roughness valleys of immersed surfaces. If water vapor condenses, that too leads to invasion. These effects have not been investigated, and are critically important to maintain surfaces dry under water. In this work, we identify the critical roughness scale, below which it is possible to sustain the vapor phase of water and/or trapped gases in roughness valleys - thus keeping the immersed surface dry. Theoretical predictions are consistent with molecular dynamics simulations and experiments.

  8. The role of surface water redistribution in an area of patterned vegetation in a semi-arid environment, south-west Niger

    Science.gov (United States)

    Bromley, J.; Brouwer, J.; Barker, A. P.; Gaze, S. R.; Valentine, C.

    1997-11-01

    The surface hydrology of a semi-arid area of patterned vegetation in south-west Niger is described. In this region alternating bands of vegetation and bare ground aligned along the contours of a gently sloping terrain give rise to a phenomenon known as `brousse tigrée' (tiger bush). At the selected study site the vegetation bands are 10-30 m wide, separated by 50-100-m-wide bands of bare ground. Five species of shrub dominate, Guiera senegalensis, Combretum micranthum, C. nigricans, Acacia ataxacantha and A. macrostachya. Herbaceous vegetation is generally limited to the upslope edges of vegetation bands. A comprehensive field programme was undertaken to investigate the hydrology. Topographic, vegetation and surface feature surveys were carried out in conjunction with the measurement of rainfall, surface and subsurface hydraulic conductivity, particle size and soil moisture content. Four types of vegetation class are recognised, each tending to occupy a constant position relative to the others and to the regional slope. In a downslope direction the classes are: bare ground, grassy open bush, closed bush, bare open bush, bare ground etc. The nature of the ground surface is closely linked to the vegetation class. Over the bare, bare open and grassy open classes various types of surface crust are present with each type of crust tending to occupy a constant position on the regional slope relative to the vegetation class and other crust types. Below closed bush crusts are generally absent. The typical downslope sequence from the downslope boundary of a vegetation band is: structural (sieving) crust→erosion crust→(gravel crust)→sedimentation crust→microphytic sedimentation crust→no crust→sieving crust, etc. It is also shown that these crust types are dynamic and evolve from one to the other as hydrological conditions change. Hydraulic conductivities of surface crusts are low, typically falling within the range 10 -6-10 -7 m s -1. The presence of large

  9. Artificial Ground Water Recharge with Surface Water

    Science.gov (United States)

    Heviánková, Silvie; Marschalko, Marian; Chromíková, Jitka; Kyncl, Miroslav; Korabík, Michal

    2016-10-01

    With regard to the adverse manifestations of the recent climatic conditions, Europe as well as the world have been facing the problem of dry periods that reduce the possibility of drawing drinking water from the underground sources. The paper aims to describe artificial ground water recharge (infiltration) that may be used to restock underground sources with surface water from natural streams. Among many conditions, it aims to specify the boundary and operational conditions of the individual aspects of the artificial ground water recharge technology. The principle of artificial infiltration lies in the design of a technical system, by means of which it is possible to conduct surplus water from one place (in this case a natural stream) into another place (an infiltration basin in this case). This way, the water begins to infiltrate into the underground resources of drinking water, while the mixed water composition corresponds to the water parameters required for drinking water.

  10. Preliminary monitoring of faecal indicator organisms of surface water ...

    African Journals Online (AJOL)

    Preliminary monitoring of faecal indicator organisms of surface water: A case study ... in Mvudi River used as a source of domestic water for people who live around it. ... of Water Affairs and Forestry of South Africa (DWAF) and the World Health ...

  11. Water service delivery challenges in a small South African municipality

    African Journals Online (AJOL)

    Water service delivery challenges in a small South African municipality: Identifying and .... improve integrated water resource management processes in South Africa. .... Grahamstown West comprises the town's central business district and ...

  12. Stormwater harvesting: Improving water security in South Africa's urban areas

    Directory of Open Access Journals (Sweden)

    Lloyd Fisher-Jeffes

    2017-01-01

    Full Text Available The drought experienced in South Africa in 2016 one of the worst in decades has left many urbanised parts of the country with limited access to water, and food production has been affected. If a future water crisis is to be averted, the country needs to conserve current water supplies, reduce its reliance on conventional surface water schemes, and seek alternative sources of water supply. Within urban areas, municipalities must find ways to adapt to, and mitigate the threats from, water insecurity resulting from, inter alia, droughts, climate change and increasing water demand driven by population growth and rising standards of living. Stormwater harvesting (SWH is one possible alternative water resource that could supplement traditional urban water supplies, as well as simultaneously offer a range of social and environmental benefits. We set out three position statements relating to how SWH can: improve water security and increase resilience to climate change in urban areas; prevent frequent flooding; and provide additional benefits to society. We also identify priority research areas for the future in order to target and support the appropriate uptake of SWH in South Africa, including testing the viability of SWH through the use of real-time control and managed aquifer recharge.

  13. Monitoring of selected priority and emerging contaminants in the Guadalquivir River and other related surface waters in the province of Jaén, South East Spain.

    Science.gov (United States)

    Robles-Molina, José; Gilbert-López, Bienvenida; García-Reyes, Juan F; Molina-Díaz, Antonio

    2014-05-01

    The province of Jaén counts with four natural parks, numerous rivers, reservoirs and wetlands; moreover, it is probably the region with higher olive oil production in the world, which makes this zone a proper target to be studied based on the European Water Framework Directive 2000/60/CE. The aim of this survey is to monitor a total number of 373 compounds belonging to different families (pesticides, PAHs, nitrosamines, drugs of abuse, pharmaceuticals and life-style compounds) in surface waters located at different points of the province of Jaén. Among these compounds some priority organic substances (regulated by the EU Directive 2008/105/EC) and pollutants of emerging concern (not regulated yet) can be found. A liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) method covering 340 compounds was developed and applied, together with a gas chromatography triple-quadrupole mass spectrometry (GC-MS/MS) method which enabled the analysis of 63 organic contaminants (30 of these compounds are analyzed by LC-TOFMS as well). From April 2009 to November 2010 a total of 83 surface water samples were collected (rivers, reservoirs and wetlands). In this period numerous organic contaminants were detected, most of them at the ng L(-1) level. The most frequently priority substances found were chlorpyrifos ethyl, diuron and hexachlorobenzene. Within the other groups, the most frequently detected compounds were: terbuthylazine, oxyfluorfen, desethyl terbuthylazine, diphenylamine (pesticide family); fluorene, phenanthrene, pyrene (PAHs group), codeine, paracetamol (pharmaceuticals compounds) and caffeine, nicotine (life-style compounds). As is could be expected, the total concentration of emerging contaminants is distinctly larger than that of priority pollutants, highlighting the importance of continuing with the study of their presence, fate and effects in aquatic environments. However, concentration levels (at the ng per liter level) are low in

  14. Total Phosphorus in Surface Water

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALP is reported in kilograms/hectare/year. More information about these resources, including the...

  15. Total Nitrogen in Surface Water

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess nitrogen in surface water can result in eutrophication. TOTALN is reported in kilograms/hectare/year. More information about these resources, including the...

  16. Free Surface Water Tunnel (FSWT)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Free Surface Water Tunnel consists of the intake plenum, the test section and the exit plenum. The intake plenum starts with a perforated pipe that...

  17. Ecology, water and enterprise development in selected rural South ...

    African Journals Online (AJOL)

    Ecology, water and enterprise development in selected rural South African towns. ... in enterprise development whether in water-abundant or water-scarce areas; these ... development dynamics in towns, which are 'enterprise ecosystems'.

  18. Irrigation methods for efficient water application: 40 years of South ...

    African Journals Online (AJOL)

    Irrigation methods for efficient water application: 40 years of South African ... to a specific situation rather than by calculating various performance indicators. ... of Irrigation Water Use covers 4 levels of water-management infrastructure: the ...

  19. Assessment of water quality in the South Indian River Water Control District, Palm Beach County, Florida, 1989-94

    Science.gov (United States)

    Lietz, A.C.

    1996-01-01

    A study was conducted to assess ground-water and surface-water quality in the South Indian River Water Control District in northern Palm Beach County from 1989 to 1994. Contamination of the surficial aquifer system and availability of a potable water supply have become of increasing concern. The study consisted of sampling 11 ground-water wells and 14 surface- water sites for determination of major inorganic constituents and physical characteristics, trace metals, nitrogen and phosphorus species, and synthetic organic compounds. Sodium and chloride concentrations exceeded Florida drinking-water standards in ground water at two wells, dissolved- solids concentrations at five ground-water wells and one surface-water site, and color values at all 11 ground-water wells and all 14 surface-water sites. Other constituents also exhibited concentrations that exceeded drinking-water standards. Cadmium and zinc concentrations exceeded the standards in ground water at one well, and lead concentrations exceeded the standard in ground water at five wells. Nitrogen and phosphorus specie concentrations did not exceed respective drinking-water standards in any ground-water or surface-water samples. Several synthetic organic compounds were detected at or above 50 micrograms per liter in water samples collected from six ground-water wells and three surface-water sites.

  20. Marine water-quality management in South- Africa

    CSIR Research Space (South Africa)

    Taljaard, Susan

    1995-01-01

    Full Text Available In South Africa the ultimate goal in water quality management is to keep the water resources suitable for all ''beneficial uses''. Beneficial uses provide a basis for the derivation of water quality guidelines, which, for South Africa, are defined...

  1. Groundwater–Surface Water Exchange

    DEFF Research Database (Denmark)

    Karan, Sachin

    The exchange of groundwater-surface water has been invetigated in the western part of Denmark. Holtum AA provides the framework for all the performed investigations. Several methods are used, primarily eld based measurements ombined with numerical models to achieve insight to the governing...... processes of interaction between groundwater and surface water. By using heat as a tracer it has been possible to use temperature directly as calibrationtargets in a groundwater and heat transport model. Thus, it is possible to use heat investigate the change in groundwater discharge in dynamic conditions...... by using simple temperature devices along a stream to delineate the areas of interest in regard to GW{SW exchange. Thus, at several locations in a stream a temperature data logger was placed in the water column and right at the streambed-water interface. By looking at the correlation of streambed...

  2. Groundwater–Surface Water Exchange

    DEFF Research Database (Denmark)

    Karan, Sachin

    The exchange of groundwater-surface water has been invetigated in the western part of Denmark. Holtum AA provides the framework for all the performed investigations. Several methods are used, primarily eld based measurements ombined with numerical models to achieve insight to the governing...... processes of interaction between groundwater and surface water. By using heat as a tracer it has been possible to use temperature directly as calibrationtargets in a groundwater and heat transport model. Thus, it is possible to use heat investigate the change in groundwater discharge in dynamic conditions...... by using simple temperature devices along a stream to delineate the areas of interest in regard to GW{SW exchange. Thus, at several locations in a stream a temperature data logger was placed in the water column and right at the streambed-water interface. By looking at the correlation of streambed...

  3. Seasonal Variability of South Atlantic Central Water

    Science.gov (United States)

    Nobrega Passos, E.; de Freitas Assad, L.; Landau, L.

    2013-05-01

    The South Atlantic Ocean (SAO) is constituted by different density water masses. Among these, the South Atlantic Central Water (SACW) is formed on the Brazil-Falkland Confluence region (BFC) and once formed, it becomes part of the Subtropical Gyre. When approaching again the Brazilian coast, this water mass bifurcates next to São Tomé Cape and part of it flows to the North and part to the South. There is another bifurcation that formed the sub-gyre of the SAO and occurs near 30°S. This work aims to analyze the seasonal variability associated to the SACW trajectory on the SAO basin. To achieve this goal, ECCO2 project's time series of prognostic fields were analysed. The parameters evaluated were temperature, salinity and the zonal and meridional velocity components in averaged monthly fields between January 1992 and November 2010. First a climatological year was calculated and was composed by means from all time series for each month. And second, it was estimate seasonally means for the south hemisphere to summer, autumn, winter and springer. For the analysis, the SACW was separated from the rest of the water masses by isolating it for its temperature, salinity and density index. Then the volume transport (VT) was calculated for seven different sections: A (10°S and 36°W-30°W), B (35°S and 55°W-45°W), C (40°W and 37°S-43°S), D (34°S and 7°E-20°E), E (20°E and 34°S-45°S), F (20°W and 27°S-33°S) and G (10°W and 20°S-25°S). The VT integrated on the water column occupied by SACW was calculated from the zonal and meridional velocities. The analysis showed that the VT balance between the sections is consistent with the climatologic analysis, according to scientific references. The analysis of the climatological VT showed that the VT field integrated in SAWC levels is also consistent with scientific reference. On the seasonal analysis, the sections A and F show a stronger VT during autumn. Since section A is formed from part of the flux of section

  4. Mobile surface water filtration system

    Directory of Open Access Journals (Sweden)

    Aashish Vatsyayan

    2012-09-01

    Full Text Available To design a mobile system for surface water filtrationMethodology: the filtration of surface impurities begins with their retraction to concentrated thickness using non ionising surfactants, then isolation using surface tension property and sedimentation of impurities in process chamber using electrocoagulation. Result:following studies done to determine the rate of spreading of crude oil on water a method for retraction of spread crude oil to concentrated volumes is developed involving addition of non -ionising surfactants in contrast to use of dispersants. Electrocoagulation process involves multiple processes taking place to lead to depositionof impurities such as oil, grease, metals. Studies of experiments conducted reveals parameters necessary for design of electrocoagulation process chamber though a holistic approach towards system designing is still required. Propeller theory is used in determining the required design of propeller and the desired thrust, the overall structure will finally contribute in deciding the choice of propeller.

  5. Water resources of south-central Missouri

    Science.gov (United States)

    Gann, E.E.; Harvey, Edward Joseph; Miller, Don E.

    1976-01-01

    This atlas describes hydrology in an area of approximately 23 ,000 sq mi and includes all or parts of 38 counties in Missouri. The area is bounded on the north by the southern edge of the Missouri River flood plain, on the east by the Mississippi River and the Plateaus-Lowlands boundary (Ozark Escarpment), on the south by the Missouri-Arkansas State line, and on the west by the western drainage divides of the Gasconade and White River basins. The alluvial valley of the Missouri River is excluded. Although the populations of several rural counties in the area have declined in recent years, significant population increases have occurred in the vicinity of the two principal population centers, St. Louis in the northeast and Springfield in the southwest. Future population increases are expected to occur as a result of continued urban expansion, increased recreational use of land and water resources, and additional development of the mining industry. (Woodard-USGS)

  6. A drinking water quality framework for South Africa

    African Journals Online (AJOL)

    Quality Framework for South Africa to enable effective management of drinking water quality and the protection of public health. ... to monitor, manage, communicate and regulate drinking water quality. ... Inadequate WSA institutional capacity (staffing, funding, .... Although demonstrating compliance with regulatory limits.

  7. Integrated water resource assessment for the Adelaide region, South Australia

    Science.gov (United States)

    Cox, James W.; Akeroyd, Michele; Oliver, Danielle P.

    2016-10-01

    South Australia is the driest state in the driest inhabited country in the world, Australia. Consequently, water is one of South Australia's highest priorities. Focus on water research and sources of water in the state became more critical during the Millenium drought that occurred between 1997 and 2011. In response to increased concern about water sources the South Australian government established The Goyder Institute for Water Research - a partnership between the South Australian State Government, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Flinders University, University of Adelaide and University of South Australia. The Goyder Institute undertakes cutting-edge science to inform the development of innovative integrated water management strategies to ensure South Australia's ongoing water security and enhance the South Australian Government's capacity to develop and deliver science-based policy solutions in water management. This paper focuses on the integrated water resource assessment of the northern Adelaide region, including the key research investments in water and climate, and how this information is being utilised by decision makers in the region.

  8. Coccolith distribution patterns in South Atlantic and Southern Ocean surface sediments in relation to environmental gradients

    DEFF Research Database (Denmark)

    Boeckel, B.; Baumann, K.-H.; Henrich, R.;

    2006-01-01

    In this study, the coccolith compositions of 213 surface sediment samples from the South Atlantic and Southern Ocean were analysed with respect to the environmental parameters of the overlying surface waters. From this data set, the abundance patterns of the main species and their ecological...... species, six surface sediment assemblages have been identified, which reflect the distribution and characteristics of the overlying surface waters. Their distribution appears to be mainly a function of the relative position of the nutricline and thermocline in the overlying photic zone. © 2006 Elsevier...

  9. North Inlet-Winyah Bay National Estuarine Research Reserve's (NERR) Estuarine Surface Water Nutrient, Suspended Sediment, and Chlorophyll a Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 1993-2001

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — A one 1000 ml (one Liter) water sample was collected every 20 days at 2 hour and 4 minute intervals for 2 complete tidal cycles (26 hours) with an ISCO automated...

  10. Assessment of the Incidence of Enteric Adenovirus Species and Serotypes in Surface Waters in the Eastern Cape Province of South Africa: Tyume River as a Case Study

    Directory of Open Access Journals (Sweden)

    Timothy Sibanda

    2012-01-01

    Full Text Available TaqMan real-time PCR was used for the detection and quantitation of adenoviruses in Tyume River water samples over a 12-month period. A total of 72 samples were analysed, and 22 samples were positive for adenovirus. Of the positive samples, 18 were collected from downstream sampling points. Among the downstream sampling points, adenovirus detection rate increased with distance downstream, being 28%, 33%, and 39% for Alice, Drayini, and Manqulweni, respectively. The Alice sampling site had the highest concentrations of adenovirus ranging between 6.54×103 genome copies/L and 8.49×104 genome copies/L. The observed trend could have been expected considering the level of anthropogenic activities in areas along the lower stretch of Tyume River, with the major one being the effluent of treated and semi treated sewage from wastewater treatment facilities. Adenovirus detection was sporadic at most sampling sites. Multiplex conventional PCR was used for the detection of clinically important adenovirus species B, C, and F and their serotypes. Species C and F adenoviruses were detected in 77% and 18% of the samples, respectively. Most adenovirus positive samples were obtained from areas of increased population densities. The presence of adenoviruses may confirm the risk of its transmission to the human population.

  11. Ground-water and precipitation data for South Carolina, 1990

    Science.gov (United States)

    Conrads, Paul A.; Jones, Kathy H.; Stringfield, Whitney J.

    1994-01-01

    Continuous water-level data collected from 53 wells in South Carolina during 1990 provide the basic data for this report. Hydrographs are presented for selected wells to illustrate the effects that changes in ground-water recharge and artificial ground-water discharge have had on the ground-water reservoirs in the State. Daily mean water levels are listed in tables. Monthly mean water levels for 1990 and for the entire period of record at each monitoring well are depicted in hydrographs. Also included are precipitation records from ten National Weather Service stations in South Carolina.

  12. Characterizing Surface Transport Barriers in the South China Sea

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Characterizing Surface Transport Barriers in the South...in mathematical methods for detecting key Lagrangian transport structures in velocity field data sets for spatially complex, time- dependent, ocean...surface flows. Such transport structures are typically not inherently obvious in snapshots of the Eulerian velocity field and require analysis

  13. Hydrogen peroxide in deep waters from the Mediterranean Sea, South Atlantic and South Pacific Oceans

    Science.gov (United States)

    Hopwood, Mark J.; Rapp, Insa; Schlosser, Christian; Achterberg, Eric P.

    2017-03-01

    Hydrogen peroxide (H2O2) is present ubiquitously in marine surface waters where it is a reactive intermediate in the cycling of many trace elements. Photochemical processes are considered the dominant natural H2O2 source, yet cannot explain nanomolar H2O2 concentrations below the photic zone. Here, we determined the concentration of H2O2 in full depth profiles across three ocean basins (Mediterranean Sea, South Atlantic and South Pacific Oceans). To determine the accuracy of H2O2 measurements in the deep ocean we also re-assessed the contribution of interfering species to ‘apparent H2O2’, as analysed by the luminol based chemiluminescence technique. Within the vicinity of coastal oxygen minimum zones, accurate measurement of H2O2 was not possible due to interference from Fe(II). Offshore, in deep (>1000 m) waters H2O2 concentrations ranged from 0.25 ± 0.27 nM (Mediterranean, Balearics-Algeria) to 2.9 ± 2.2 nM (Mediterranean, Corsica-France). Our results indicate that a dark, pelagic H2O2 production mechanism must occur throughout the deep ocean. A bacterial source of H2O2 is the most likely origin and we show that this source is likely sufficient to account for all of the observed H2O2 in the deep ocean.

  14. Hydrogen peroxide in deep waters from the Mediterranean Sea, South Atlantic and South Pacific Oceans

    Science.gov (United States)

    Hopwood, Mark J.; Rapp, Insa; Schlosser, Christian; Achterberg, Eric P.

    2017-01-01

    Hydrogen peroxide (H2O2) is present ubiquitously in marine surface waters where it is a reactive intermediate in the cycling of many trace elements. Photochemical processes are considered the dominant natural H2O2 source, yet cannot explain nanomolar H2O2 concentrations below the photic zone. Here, we determined the concentration of H2O2 in full depth profiles across three ocean basins (Mediterranean Sea, South Atlantic and South Pacific Oceans). To determine the accuracy of H2O2 measurements in the deep ocean we also re-assessed the contribution of interfering species to ‘apparent H2O2’, as analysed by the luminol based chemiluminescence technique. Within the vicinity of coastal oxygen minimum zones, accurate measurement of H2O2 was not possible due to interference from Fe(II). Offshore, in deep (>1000 m) waters H2O2 concentrations ranged from 0.25 ± 0.27 nM (Mediterranean, Balearics-Algeria) to 2.9 ± 2.2 nM (Mediterranean, Corsica-France). Our results indicate that a dark, pelagic H2O2 production mechanism must occur throughout the deep ocean. A bacterial source of H2O2 is the most likely origin and we show that this source is likely sufficient to account for all of the observed H2O2 in the deep ocean. PMID:28266529

  15. Water molecules orientation in surface layer

    Science.gov (United States)

    Klingo, V. V.

    2000-08-01

    The water molecules orientation has been investigated theoretically in the water surface layer. The surface molecule orientation is determined by the direction of a molecule dipole moment in relation to outward normal to the water surface. Entropy expressions of the superficial molecules in statistical meaning and from thermodynamical approach to a liquid surface tension have been found. The molecules share directed opposite to the outward normal that is hydrogen protons inside is equal 51.6%. 48.4% water molecules are directed along to surface outward normal that is by oxygen inside. A potential jump at the water surface layer amounts about 0.2 volts.

  16. Taste and odour issues in South Korea's drinking water industry.

    Science.gov (United States)

    Bae, B U; Shin, H S; Choi, J J

    2007-01-01

    This paper reviews taste and odour (T&O) issues of South Korea's water industry. For this purpose, an overview of the water supply systems and drinking water standards is presented and some results from citizen surveys for customer satisfaction are included. A case study is presented in which the water intake was shifted from inside a main reservoir to a downstream location due to T&O problems. It is true that the South Korean water industry has long relied on the tolerance of consumers for periodic T&O events. Recently the South Korean water industry has become aware that the T&O problems are at the centre of consumers' concerns and has taken several positive approaches. These include monitoring T&O events using sensory and instrumental methods, installation of a baffled-channel PAC contactor and application of advanced water treatment processes.

  17. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment

  18. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment concentrati

  19. Scenarios for the South African water sector in 2025; Paper

    CSIR Research Space (South Africa)

    Claassen, Marius

    2013-01-01

    Full Text Available In 2008 the Water Research Commission initiated a project to develop ‘Water Sector Institutional Landscape in 2025 Scenarios’. The aim was to build knowledge about key drivers and uncertainties related to the future of the South African water sector...

  20. Monitoring drinking water quality in South Africa: Designing ...

    African Journals Online (AJOL)

    In South Africa, the management and monitoring of drinking water quality is governed by policies and regulations based .... The measures for improvement of monitoring were: .... purposes, the effectiveness and desirability of a government.

  1. The relevance of diatoms for water quality assessment in South ...

    African Journals Online (AJOL)

    The relevance of diatoms for water quality assessment in South Africa: A ... Deliberate determination of responses to management strategies or impacts arising from a ... may be established to augment the current use of invertebrate indicators.

  2. South Asia Water Resources Workshop: An effort to promote water quality data sharing in South Asia

    Energy Technology Data Exchange (ETDEWEB)

    RAJEN,GAURAV; BIRINGER,KENT L.; BETSILL,J. DAVID

    2000-04-01

    To promote cooperation in South Asia on environmental research, an international working group comprised of participants from Bangladesh, India, Nepal, Pakistan, Sri Lanka, and the US convened at the Soaltee Hotel in Kathmandu, Nepal, September 12 to 14, 1999. The workshop was sponsored in part by the Cooperative Monitoring Center (CMC) at Sandia National Laboratories in Albuquerque, New Mexico, through funding provided by the Department of Energy (DOE) Office of Nonproliferation and National Security. The CMC promotes collaborations among scientists and researchers in regions throughout the world as a means of achieving common regional security objectives. In the long term, the workshop organizers and participants are interested in the significance of regional information sharing as a means to build confidence and reduce conflict. The intermediate interests of the group focus on activities that might eventually foster regional management of some aspects of water resources utilization. The immediate purpose of the workshop was to begin the implementation phase of a project to collect and share water quality information at a number of river and coastal estuary locations throughout the region. The workshop participants achieved four objectives: (1) gaining a better understanding of the partner organizations involved; (2) garnering the support of existing regional organizations promoting environmental cooperation in South Asia; (3) identifying sites within the region at which data is to be collected; and (4) instituting a data and information collection and sharing process.

  3. Drinking water insecurity: water quality and access in coastal south-western Bangladesh.

    Science.gov (United States)

    Benneyworth, Laura; Gilligan, Jonathan; Ayers, John C; Goodbred, Steven; George, Gregory; Carrico, Amanda; Karim, Md Rezaul; Akter, Farjana; Fry, David; Donato, Katherine; Piya, Bhumika

    2016-01-01

    National drinking water assessments for Bangladesh do not reflect local variability, or temporal differences. This paper reports on the findings of an interdisciplinary investigation of drinking water insecurity in a rural coastal south-western Bangladesh. Drinking water quality is assessed by comparison of locally measured concentrations to national levels and water quality criteria; resident's access to potable water and their perceptions are based on local social surveys. Residents in the study area use groundwater far less than the national average; salinity and local rainwater scarcity necessitates the use of multiple water sources throughout the year. Groundwater concentrations of arsenic and specific conductivity (SpC) were greater than surface water (pond) concentrations; there was no statistically significant seasonal difference in mean concentrations in groundwater, but there was for ponds, with arsenic higher in the dry season. Average arsenic concentrations in local water drinking were 2-4 times times the national average. All of the local groundwater samples exceeded the Bangladesh guidance for SpC, although the majority of residents surveyed did not perceive their water as having a 'bad' or 'salty' taste.

  4. Rocky Mountain Arsenal surface water management plan : water year 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Surface Water Management Plan (SWMP) for Water Year 2003 (WY 2003) (October I, 2002 to September 30, 2003) is an assessment of the nonpotable water demands at...

  5. Rocky Mountain Arsenal surface water management plan : water year 2005

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Surface Water Management Plan for Water Year (WY) 2005 (October 1, 2004 to September 30, 2005) is an assessment of the nonpotable water demands at the Rocky...

  6. Rocky Mountain Arsenal surface water management plan : water year 2006

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Surface Water Management Plan for Water Year (WY) 2006 (October 1, 2005 to September 30, 2006) is an assessment of the nonpotable water demands at the Rocky...

  7. Diurnal variations in water vapor over Central and South America

    Science.gov (United States)

    Meza, Amalia; Mendoza, Luciano; Clara, Bianchi

    2017-04-01

    Diurnal variations in atmospheric integrated water vapor (IWV) are studied employing IWV estimates, with a 30 minutes sampling rate, derived from Global Navigation Satellite Systems (GNSS) observations during the period 2007-2013. The analysis was performed in 70 GNSS tracking sites (GPS + GLONASS) belonging to Central and South America, which have more than 5 years of data. The selected area involves different climate types, from polar to tropical, and diverse relieves, therefore the patterns of IWV diurnal variations are very different for each station. There are many processes that could induce diurnal variations in atmospheric water vapor (Dai et al, 1999 a,b), the most relevant causes are: surface evapotranspiration, atmospheric large-scale vertical motion, atmospheric low-level moisture convergence and precipitation and vertical mixing (which affects the vertical distribution of water vapor but does not affect the IWV). Firstly, our work study the main characteristics of the IWV diurnal cycle (and for surface temperature, T) obtained for all stations together, using Principal Component Analysis (PCA). First and second PCA modes highlight the global main behaviors of IWV variability for all stations. The first mode on IWV represent the 70% of the variability and could be related to the surface evapotranspiration, while the second mode (27 % of the variability) is practically in counter phase to T variability (its first mode represent the 97% of the variability), therefore this mode could be related to breeze regime. Then, every station is separately analyzed and seasonal and local variations (relative to the relives) are detected, these results spotlight, among other characteristics, the sea and mountain breeze regime. This presentation shows the first analysis of IWV diurnal cycle performed over Central and South America and another original characteristic is PCA technique employed to infer the results. Reference: Dai, A., K. E. Trenberth, and T. R. Karl

  8. Surface water discharges from onshore stripper wells.

    Energy Technology Data Exchange (ETDEWEB)

    Veil, J. A.

    1998-01-16

    Under current US Environmental Protection Agency (EPA) rules, small onshore oil producers are allowed to discharge produced water to surface waters with approval from state agencies; but small onshore gas producers, however, are prohibited from discharging produced water to surface waters. The purpose of this report is to identify those states that allow surface water discharges from small onshore oil operations and to summarize the types of permitting controls they use. It is intended that the findings of this report will serve as a rationale to encourage the EPA to revise its rules and to remove the prohibition on surface water discharges from small gas operations.

  9. Atmospheric Longwave Infrared Emission Spectroscopy of Water Vapor at the South Pole

    OpenAIRE

    Myers, Brooke A.

    2000-01-01

    The downward infrared radiance spectrum was measured with a Michelson Long Wave Infrared (LWIR) spectrometer at the Amundsen-Scott South Pole Station. Spectra were collected year-round at the South Pole in 1998. This research focuses on the atmospheric water emission lines between 250 and 800 cm-1 (40 to 12.5 μm) region. The spectral resolution is 1 cm-1. The atmosphere over the South Pole is the driest and coldest on Earth. Winter surface temperatures average approximately -60°C, while the t...

  10. Rapid surface-water volume estimations in beaver ponds

    Science.gov (United States)

    Karran, Daniel J.; Westbrook, Cherie J.; Wheaton, Joseph M.; Johnston, Carol A.; Bedard-Haughn, Angela

    2017-02-01

    Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range of environmental settings in which beaver ponds are found. Studied were a total of 40 beaver ponds from four different sites in North and South America. The simplified volume-area-depth (V-A-h) approach, originally developed for prairie potholes, was tested. With only two measurements of pond depth and corresponding surface area, this method estimated surface-water storage in beaver ponds within 5 % on average. Beaver pond morphometry was characterized by a median basin coefficient of 0.91, and dam length and pond surface area were strongly correlated with beaver pond storage capacity, regardless of geographic setting. These attributes provide a means for coarsely estimating surface-water storage capacity in beaver ponds. Overall, this research demonstrates that reliable estimates of surface-water storage in beaver ponds only requires simple measurements derived from aerial imagery and/or brief visits to the field. Future research efforts should be directed at incorporating these simple methods into both broader beaver-related tools and catchment-scale hydrological models.

  11. Triple dividends of water consumption charges in South Africa

    Science.gov (United States)

    Letsoalo, Anthony; Blignaut, James; de Wet, Theuns; de Wit, Martin; Hess, Sebastiaan; Tol, Richard S. J.; van Heerden, Jan

    2007-05-01

    The South African government is exploring ways to address water scarcity problems by introducing a water resource management charge on the quantity of water used in sectors such as irrigated agriculture, mining, and forestry. It is expected that a more efficient water allocation, lower use, and a positive impact on poverty can be achieved. This paper reports on the validity of these claims by applying a computable general equilibrium model to analyze the triple dividend of water consumption charges in South Africa: reduced water use, more rapid economic growth, and a more equal income distribution. It is shown that an appropriate budget-neutral combination of water charges, particularly on irrigated agriculture and coal mining, and reduced indirect taxes, particularly on food, would yield triple dividends, that is, less water use, more growth, and less poverty.

  12. Drinking water vulnerability to climate change and alternatives for adaptation in coastal South and South East Asia.

    Science.gov (United States)

    Hoque, M A; Scheelbeek, P F D; Vineis, P; Khan, A E; Ahmed, K M; Butler, A P

    Drinking water in much of Asia, particularly in coastal and rural settings, is provided by a variety of sources, which are widely distributed and frequently managed at an individual or local community level. Coastal and near-inland drinking water sources in South and South East (SSE) Asia are vulnerable to contamination by seawater, most dramatically from tropical cyclone induced storm surges. This paper assesses spatial vulnerabilities to salinisation of drinking water sources due to meteorological variability and climate change along the (ca. 6000 km) coastline of SSE Asia. The risks of increasing climatic stresses are first considered, and then maps of relative vulnerability along the entire coastline are developed, using data from global scale land surface models, along with an overall vulnerability index. The results show that surface and near-surface drinking water in the coastal areas of the mega-deltas in Vietnam and Bangladesh-India are most vulnerable, putting more than 25 million people at risk of drinking 'saline' water. Climate change is likely to exacerbate this problem, with adverse consequences for health, such as prevalence of hypertension and cardiovascular diseases. There is a need for identifying locations that are most at risk of salinisation in order for policy makers and local officials to implement strategies for reducing these health impacts. To counter the risks associated with these vulnerabilities, possible adaptation measures are also outlined. We conclude that detailed and fine scale vulnerability assessments may become crucial for planning targeted adaptation programmes along these coasts.

  13. Water surface capturing by image processing

    Science.gov (United States)

    An alternative means of measuring the water surface interface during laboratory experiments is processing a series of sequentially captured images. Image processing can provide a continuous, non-intrusive record of the water surface profile whose accuracy is not dependent on water depth. More trad...

  14. Coherent water transport across the South Atlantic

    CERN Document Server

    Wang, Y; Beron-Vera, F J

    2015-01-01

    The role of mesoscale eddies in transporting Agulhas leakage is investigated using a recent technique from nonlinear dynamical systems theory applied on geostrophic currents inferred from the over two-decade-long satellite altimetry record. Eddies are found to acquire material coherence away from the Agulhas retroflection, near the Walvis Ridge in the South Atlantic. Yearly, 1 to 4 coherent material eddies are detected with diameters ranging from 40 to 280 km. A total of 23 eddy cores of about 50 km in diameter and with at least 30% of their contents traceable into the Indian Ocean were found to travel across the subtropical gyre with minor filamentation. No more than 5\\% of such cores pour their contents on the North Brazil Current. While ability of eddies to carry Agulhas leakage northwestward across the South Atlantic is supported by our analysis, this is more restricted than suggested by earlier ring transport assessments.

  15. Safe Drinking Water Information System (SDWIS) Surface Water Intakes

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a point feature dataset showing the locations of surface water intakes. These intake locations are part of the safe drinking water information system...

  16. Anti-Aliased Rendering of Water Surface

    Institute of Scientific and Technical Information of China (English)

    Xue-Ying Qin; Eihachiro Nakamae; Wei Hua; Yasuo Nagai; Qun-Sheng Peng

    2004-01-01

    Water surface is one of the most important components of landscape scenes. When rendering spacious far from the viewpoint. This is because water surface consists of stochastic water waves which are usually modeled by periodic bump mapping. The incident rays on the water surface are actually scattered by the bumped waves,pattern, we estimate this solid angle of reflected rays and trace these rays. An image-based accelerating method is adopted so that the contribution of each reflected ray can be quickly obtained without elaborate intersection calculation. We also demonstrate anti-aliased shadows of sunlight and skylight on the water surface. Both the rendered images and animations show excellent effects on the water surface of a reservoir.

  17. Biochemical characteristics and bacterial community structure of the sea surface microlayer in the South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    I. Obernosterer

    2008-05-01

    Full Text Available The chemical and biological characteristics of the surface microlayer were determined during a transect across the South Pacific Ocean in October-December 2004. Concentrations of particulate organic carbon (1.3 to 7.6-fold and nitrogen (1.4 to 7-fold, and POC:PON ratios were consistently higher in the surface microlayer as compared to surface waters (5 m. The large variability in particulate organic matter enrichment was negatively correlated to wind speed. No enhanced concentrations of dissolved organic carbon were detectable in the surface microlayer as compared to 5 m, but chromophoric dissolved organic matter was markedly enriched (by 2 to 4-fold at all sites. Based on pigment analysis and cell counts, no consistent enrichment of any of the major components of the autotrophic and heterotrophic microbial community was detectable. CE-SSCP fingerprints and CARD FISH revealed that the bacterial communities present in the surface microlayer had close similarity (>76% to those in surface waters. By contrast, bacterial heterotrophic production (3H-leucine incorporation was consistently lower in the surface microlayer than in surface waters. By applying CARD-FISH and microautoradiography, we observed that Bacteroidetes and Gammaproteobacteria dominated leucine uptake in the surface microlayer, while in surface waters Bacteroidetes and Alphaproteobacteria were the major groups accounting for leucine incorporation. Our results demonstrate that the microbial community in the surface microlayer closely resembles that of the surface waters of the open ocean. Even a short residence in the surface microlayer influences leucine incorporation by different bacterial groups, probably as a response to the differences in the physical and chemical nature of the two layers.

  18. Citrus water use in South Africa

    CSIR Research Space (South Africa)

    Vahrmeijer, JT

    2012-09-01

    Full Text Available intervenes through policy instruments to influence water use behaviour. Citrus growers need to take heed of these changes in policy as the majority of citrus orchards are irrigated and more detailed information on seasonal water requirements and irrigation...

  19. SURFACE WATER QUALITY IN THE RIVER PRUT

    Directory of Open Access Journals (Sweden)

    MIHAELA DUMITRAN

    2011-03-01

    Full Text Available Water is an increasingly important and why it is important to surfacewater quality, which is given by the analysis of physical - chemical, biological andobserving the investigation of water, biota, environments investigation. Analysis ofthe Prut river in terms of biological and physical elements - chemical. Evaluationof ecological and chemical status of water was done according to order of approvalof the standard classification nr.161/2006 surface water to determine the ecologicalstatus of water bodies

  20. Carbon isotopic record of foraminifers in surface sediments from the South China Sea and its significance

    Institute of Scientific and Technical Information of China (English)

    CHENG Xinrong; WANG Pinxian; HUANG Baoqi; LIU Chuanlian; JIAN Zhimin; ZHAO Quanhong; LI Jianru; TIAN Jun; XU Jian

    2005-01-01

    The study is based on stable carbon isotopic measurements of 112 foraminiferal samples from surface sediments at 40 sites in the South China Sea (SCS).δ13C of foraminifers and △δ13C between planktonic and benthic foraminiferal species exhibit a low value area at the northeastern and southern ends of the SCS. It is correlated with the nutrient distributional pattern in the SCS and circumjacent area, the influence of the northeastern and southwestern monsoons on water flow and water chemistry in the SCS. The monsoons have not only brought nutrients to the upper part of the sea but also disturbed water and decreased difference between the surface and bottom water. Its influence is most obvious at both ends, which resulted in the low value areas in δ13C and △δ13C at the ends. The distributional pattern of the stable carbon isotope in the SCS is a reflection of the East Asian monsoons.

  1. Regional distribution patterns of chemical parameters in surface sediments of the south-western Baltic Sea and their possible causes

    Science.gov (United States)

    Leipe, T.; Naumann, M.; Tauber, F.; Radtke, H.; Friedland, R.; Hiller, A.; Arz, H. W.

    2017-06-01

    This study presents selected results of a sediment geochemical mapping program of German territorial waters in the south-western Baltic Sea. The field work was conducted mainly during the early 2000s. Due to the strong variability of sediment types in the study area, it was decided to separate and analyse the fine fraction (confidently pinpointing geochemical "anomalies" in surface sediments of the south-western Baltic Sea.

  2. Manufacturing and characterisation of water repellent surfaces

    DEFF Research Database (Denmark)

    De Grave, Arnaud; Botija, Pablo; Hansen, Hans Nørgaard

    2006-01-01

    design criteria for such surfaces. The problem of adapting this behaviour to artificially roughened surfaces is addressed by providing design criteria for superhydrophobic, water-repellent and self-cleaning surfaces according to the concrete performance desired for them. Different kind of manufacturing...

  3. Socioeconomic differentials and availability of domestic water in South Africa

    Science.gov (United States)

    Dungumaro, Esther W.

    The past few decades has seen massive efforts to increasing provision of domestic water. However, water is still unavailable to many people most of them located in sub-Saharan Africa, South Asia and East Asia. Furthermore, availability of water varies greatly both spatially and temporary. While other people pay so dearly for domestic water others have an easy access to adequate clean water and sanitation. Accessibility and affordability of domestic water and sanitation is determined by a great variety of factors including socioeconomic status of households. The main objective of the paper is to inform on factors which need to be taken into account when coming up with projects to provide domestic water. It is more critical when the issue of water pricing comes into the equation. Water pricing has many facets, including equity, willingness to pay and affordability. In this premise, it is deemed important to understand the socioeconomic characteristics of the people before deciding on the amount of money they will have to pay for water consumption. It is argued that understanding people’s socioeconomic situation will greatly help to ensure that principles of sustainability and equity in water allocation and pricing are achieved. To do so, the paper utilized 2002 South Africa General Household Survey (GHS), to analyze socioeconomic variables and availability of domestic water. Analysis was mainly descriptive. However, logistic regression analysis was also utilized to determine the likelihood of living in a household that obtain water from a safe source. The study found that there is a strong relationship between availability of domestic water and socioeconomic conditions. Economic status, household size and to a lesser extent gender of head of household were found to be strong predictors of living in a household which obtained water from a safe source. The paper recommends that needs and priorities for interventions in water provision should take into account

  4. Concentrations of selected constituents in surface-water and streambed-sediment samples collected from streams in and near an area of oil and natural-gas development, south-central Texas, 2011-13

    Science.gov (United States)

    Opsahl, Stephen P.; Crow, Cassi L.

    2014-01-01

    During 2011–13, the U.S. Geological Survey, in cooperation with the San Antonio River Authority and the Guadalupe-Blanco River Authority, analyzed surface-water and streambed-sediment samples collected from 10 sites in the San Antonio River Basin to provide data for a broad range of constituents that might be associated with hydraulic fracturing and the produced waters that are a consequence of hydraulic fracturing. Among surface-water samples, all sulfide concentrations were less than the method detection limit of 0.79 milligrams per liter. Four glycols—diethylene glycol, ethylene glycol, propylene glycol, and triethylene glycol—were analyzed for in surface-water samples collected for this study, and none were detected. Of the 91 semivolatile organic compounds analyzed for this study, there were six detections, all but one of which were in storm-runoff samples. The base-flow sample collected at the San Antonio River at Goliad, Tex. (SAR Goliad), site contained bis(2-ethylhexyl) phthalate, a plasticizer in polyvinyl chloride and a constituent in hydraulic fracturing fluids. The storm-runoff samples collected at the San Antonio River near Elmendorf, Tex. (SAR Elmendorf), and Ecleto Creek at County Road 326 near Runge, Tex. (Ecleto 2), sites also contained bis(2-ethylhexyl) phthalate. The storm-runoff sample collected at the SAR Elmendorf site contained the plasticizer diethyl phthalate. Both storm-runoff samples collected at the Ecleto Creek near Runge, Tex. (Ecleto 1), and Ecleto 2 sites contained benzyl alcohol, a solvent commonly used in paints. Of the 67 volatile organic compounds analyzed in this study, there were a total of six detections, all of which were in base-flow samples. The surface-water sample collected at the SAR Elmendorf site contained bromodichloromethane, dibromochloromethane, and trichloromethane, all of which are disinfection byproducts associated with the chlorination of municipal water supplies and of treated municipal wastewater. The

  5. Surface Water Quality Monitoring Sites

    Data.gov (United States)

    Minnesota Department of Natural Resources — The MN Department of Agriculture (MDA) is charged with periodically collecting and analyzing water samples from selected locations throughout the state to determine...

  6. SMOS Sea Surface Salinity Validation in the South China Sea

    Science.gov (United States)

    Ren, Yongzheng; Li, Xiaoming; Dong, Qing

    2013-01-01

    In November 2009, the European Space Agency (ESA) launched the first soil moisture and ocean salinity (SMOS) satellite, which represented the first use of spaceborne remote sensing tools to probe global sea surface salinity (SSS). The SMOS satellite carries a microwave imaging radiometer with aperture synthesis (MIRAS) for detection in the microwave L-band as the only payload. The MIRAS instrument is expected to provide a global SSS distribution with a spatial resolution of approximately 100 km and an accuracy of 0.1-0.2 practical salinity units (psu). The South China Sea is semi-enclosed, and the sea conditions are relatively complex. The suitability of ESA SMOS salinity products for the South China Sea has not been validated. Therefore, using SSS data measured during an expedition in the South China Sea, which was sponsored by China Natural Science Foundation and conducted in the fall of 2011, this paper validated the SSS products released by ESA, which were retrieved using three sea surface roughness models. To analyze the effect of the spatial resolution on the weekly average SMOS SSS distribution, the weekly average salinity data were averaged to reduce the spatial resolution to 0.25 ° x 0.25°. These average data were then compared to the measured data, followed by an analysis of the error variation. In addition, the effects of the orbital track (ascending or descending) on the SSS retrieval were analyzed.

  7. The South Australian Safe Drinking Water Act: summary of the first year of operation.

    Science.gov (United States)

    Froscio, Suzanne M; Bolton, Natalie; Cooke, Renay; Wittholz, Michelle; Cunliffe, David

    2016-06-01

    The Safe Drinking Water Act 2011 was introduced in South Australia to provide clear direction to drinking water providers on how to achieve water safety. The Act requires drinking water providers to register with SA Health and develop a risk management plan (RMP) for their water supply that includes operational and verification monitoring plans and an incident notification and communication protocol. During the first year of operation, 212 drinking water providers registered under the Act, including one major water utility and a range of small to medium sized providers in regional and remote areas of the State. Information was captured on water source(s) used and water treatment. Rainwater was the most frequently reported drinking water source (66%), followed by bore water (13%), on-supply or carting of mains water (13%), mixed source (rainwater with bore water backup) (6%) and surface water (3%). The majority of providers (91%) treated the water supply, 87% used disinfection. During the first year of operation, 16 water quality incidents were formally reported to SA Health. These included both microbial and chemical incidents. Case studies presented highlight how the RMPs are assisting drinking water providers to identify incidents of potential health concern and implement corrective actions.

  8. Ocean-to-Ocean Dissimilarities of Salty Subtropical Surface Water

    Science.gov (United States)

    Gordon, A. L.

    2014-12-01

    Each ocean basin displays its own 'personality', reflecting its degree of isolation or connectivity to the global ocean, its place in the interocean exchange network and associated ocean overturning circulation systems, as well as regional circulation and air-sea exchange patterns. While dissimilarities are most notable in the northern hemisphere (the salty North Atlantic vs the fresher North Pacific; as well as the salty Arabian and the fresher Bay of Bengal, a miniature Atlantic/Pacific analog?) far removed from the grand equalizing interocean link of the circum-Antarctic belt, and where large continental blocks impose contrasting forcing, the southern hemisphere ocean basins also display differences. Ocean to ocean dissimilarities are evident in the dry subtropical climate belt, marked by deserts on land and salty surface ocean water. The subtropical sea surface salinity maximum (SSS-max) patterns of 5 the subtropical regimes (the North and South Atlantic, North and South Pacific, and the southern Indian Ocean) display significant dissimilarities in their relative position within their ocean basin, in the structure and seasonality of the SSS-max pattern. The near synoptic coverage of Aquarius and Argo profilers are further defining interannual variability. The South Atlantic SSS-max is pressed against the western boundary, whereas in the other regimes the SSS-max falls within the eastern half of the ocean basin, though the western South Pacific displays a secondary SSS-max. For further details see: A. Gordon, C. Giulivi, J. Busecke, F. Bingham, submitted to the SPURS Oceanography special issue.

  9. Some comments on water rights in South Africa

    Directory of Open Access Journals (Sweden)

    N Gabru

    2005-01-01

    Full Text Available Human life, as with all animal and plant life on the planet, is dependent upon fresh water. Water is not only needed to grow food, generate power and run industries, but it is also needed as a basic part of human life. Human dependency upon water is evident through history, which illustrates that human settlements have been closely linked to the availability and supply of fresh water. Access to the limited water resources in South Africa has been historically dominated by those with access to land and economic power, as a result of which the majority of South Africans have struggled to secure the right to water. Apartheid era legislation governing water did not discriminate directly on the grounds of race, but the racial imbalance in ownership of land resulted in the disproportionate denial to black people of the right to water. Beyond racial categorisations, the rural and poor urban populations were traditionally especially vulnerable in terms of the access to the right. The enactment of the Constitution of the Republic of South Africa 1996, brought the South African legal system into a new era, by including a bill of fundamental human rights (Bill of Rights. The Bill of Rights makes provision for limited socio-economic rights. Besides making provision for these human rights, the Constitution also makes provision for the establishment of state institutions supporting constitutional democracy. The Constitution has been in operation since May 1996. At this stage, it is important to take stock and measure the success of the implementation of these socio-economic rights. This assessment is important in more ways than one, especially in the light of the fact that many lawyers argued strongly against the inclusion of the second and third generation of human rights in a Bill of Rights. The argument was that these rights are not enforceable in a court of law and that they would create unnecessary expectations of food, shelter, health, water and the

  10. Surface Water Treatment Workshop Manual.

    Science.gov (United States)

    Ontario Ministry of the Environment, Toronto.

    This manual was developed for use at workshops designed to increase the knowledge of experienced water treatment plant operators. Each of the fourteen lessons in this document has clearly stated behavioral objectives to tell the trainee what he should know or do after completing that topic. Areas covered in this manual include: basic water…

  11. Evidence for water structuring forces between surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, Christopher B [ORNL; Rau, Dr. Donald [National Institutes of Health

    2011-01-01

    Structured water on apposing surfaces can generate significant energies due to reorganization and displacement as the surfaces encounter each other. Force measurements on a multitude of biological structures using the osmotic stress technique have elucidated commonalities that point toward an underlying hydration force. In this review, the forces of two contrasting systems are considered in detail: highly charged DNA and nonpolar, uncharged hydroxypropyl cellulose. Conditions for both net repulsion and attraction, along with the measured exclusion of chemically different solutes from these macromolecular surfaces, are explored and demonstrate features consistent with a hydration force origin. Specifically, the observed interaction forces can be reduced to the effects of perturbing structured surface water.

  12. [ASSESSMENT OF POTENTIAL RISK FOR CONTAMINATION OF SURFACE WATER RESERVOIRS BY PATHOGENS OF HUMAN PARASITIC DISEASES].

    Science.gov (United States)

    Khromenkova, E P; Dimidova, L L; Dumbadze, O S; Aidinov, G T; Shendo, G L; Agirov, A Kh; Batchaev, Kh Kh

    2015-01-01

    Sanitary and parasitological studies of the waste effluents and surface reservoir waters were conducted in the south of Russia. The efficiency of purification of waste effluents from the pathogens of parasitic diseases was investigated in the region's sewage-purification facilities. The water of the surface water reservoirs was found to contain helminthic eggs and larvae and intestinal protozoan cysts because of the poor purification and disinfection of service fecal sewage waters. The poor purification and disinvasion of waste effluents in the region determine the potential risk of contamination of the surface water reservoirs and infection of the population with the pathogens of human parasitic diseases.

  13. South Asia transboundary water quality monitoring workshop summary report.

    Energy Technology Data Exchange (ETDEWEB)

    Betsill, Jeffrey David; Littlefield, Adriane C.; Luetters, Frederick O.; Rajen, Gaurav

    2003-04-01

    The Cooperative Monitoring Center (CMC) promotes collaborations among scientists and researchers in several regions as a means of achieving common regional security objectives. To promote cooperation in South Asia on environmental research, an international working group made up of participants from Bangladesh, India, Nepal, Pakistan, and the United States convened in Kathmandu, Nepal, from February 17-23,2002. The workshop was held to further develop the South Asia Transboundary Water Quality Monitoring (SATWQM) project. The project is sponsored in part by the CMC located at Sandia National Laboratories in Albuquerque, New Mexico through funding provided by the US. Department of State, Regional Environmental Affairs Office, American Embassy, Kathmandu, Nepal, and the National Nuclear Security Administration's (NNSA) Office of Nonproliferation and National Security. This report summarizes the SATWQM project, the workshop objectives, process and results. The long-term interests of the participants are to develop systems for sharing regional environmental information as a means of building confidence and improving relations among South Asian countries. The more immediate interests of the group are focused on activities that foster regional sharing of water quality data in the Ganges and Indus River basins. Issues of concern to the SATWQM network participants include studying the impacts from untreated sewage and industrial effluents, agricultural run-off, salinity increases in fresh waters, the siltation and shifting of river channels, and the environmental degradation of critical habitats such as wetlands, protected forests, and endangered aquatic species conservation areas. The workshop focused on five objectives: (1) a deepened understanding of the partner organizations involved; (2) garnering the support of additional regional and national government and non-government organizations in South Asia involved in river water quality monitoring; (3) identification

  14. Transboundary water resources governance: institutional fragilities in South America

    Directory of Open Access Journals (Sweden)

    Fernanda MELLO SANT’ANNA

    2015-04-01

    Full Text Available Since the 1990s, the concept of governance rose to prominence in the literature regarding transboundary waters, as well as the international cooperation among riparian States. This article seeks to determine the fragilities in the governance of the major transboundary water resources in South America: the Amazon and La Plata River Basins. In spite of the current international agreements, including those regarding infrastructure development and supranational organizations, water governance presents fragilities related to institutional problems, lack of social participation and dif?culties in structuring a common project of development.

  15. Total Phosphorus in Surface Water (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess phosphorus in surface water can result in eutrophication. TOTALPFuture is reported in kilograms/hectare/year. More information about these resources,...

  16. Surface processing using water cluster ion beams

    Science.gov (United States)

    Takaoka, Gikan H.; Ryuto, Hiromichi; Takeuchi, Mitsuaki; Ichihashi, Gaku

    2013-07-01

    Vaporized water clusters were produced by an adiabatic expansion phenomenon, and various substrates such as Si(1 0 0), SiO2, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polycarbonate (PC) were irradiated by water cluster ion beams. The sputtered depth increased with increasing acceleration voltage, and the sputtering rate was much larger than that obtained using Ar monomer ion irradiation. The sputtering yield for PMMA was approximately 200 molecules per ion, at an acceleration voltage of 9 kV. X-ray photoelectron spectroscopy (XPS) measurements showed that high-rate sputtering for the PMMA surface can be ascribed to the surface erosion by the water cluster ion irradiation. Furthermore, the micropatterning was demonstrated on the PMMA substrate. Thus, the surface irradiation by water cluster ion beams exhibited a chemical reaction based on OH radicals, as well as excited hydrogen atoms, which resulted in a high sputtering rate and low irradiation damage of the substrate surfaces.

  17. Surface processing using water cluster ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Takaoka, Gikan H., E-mail: gtakaoka@kuee.kyoto-u.ac.jp [Photonics and Electronics Science and Engineering Center, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Ryuto, Hiromichi; Takeuchi, Mitsuaki; Ichihashi, Gaku [Photonics and Electronics Science and Engineering Center, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan)

    2013-07-15

    Vaporized water clusters were produced by an adiabatic expansion phenomenon, and various substrates such as Si(1 0 0), SiO{sub 2}, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polycarbonate (PC) were irradiated by water cluster ion beams. The sputtered depth increased with increasing acceleration voltage, and the sputtering rate was much larger than that obtained using Ar monomer ion irradiation. The sputtering yield for PMMA was approximately 200 molecules per ion, at an acceleration voltage of 9 kV. X-ray photoelectron spectroscopy (XPS) measurements showed that high-rate sputtering for the PMMA surface can be ascribed to the surface erosion by the water cluster ion irradiation. Furthermore, the micropatterning was demonstrated on the PMMA substrate. Thus, the surface irradiation by water cluster ion beams exhibited a chemical reaction based on OH radicals, as well as excited hydrogen atoms, which resulted in a high sputtering rate and low irradiation damage of the substrate surfaces.

  18. Exit Creek Water Surface Survey, June 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset consists of survey data from a longitudinal profile of water surface surveyed June 23-24, 2013 at Exit Creek, a stream draining Exit Glacier in Kenai...

  19. US Forest Service Surface Drinking Water Importance

    Data.gov (United States)

    US Forest Service, Department of Agriculture — A map service on the www depicting watershed indexes to help identify areas of interest for protecting surface drinking water quality. The dataset depicted in this...

  20. Total Nitrogen in Surface Water (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Excess nitrogen in surface water can result in eutrophication. TOTALNFuture is reported in kilograms/hectare/year. More information about these resources, including...

  1. Surface Waters Information Management System (SWIMS)

    Data.gov (United States)

    Kansas Data Access and Support Center — The Surface Waters Information Management System (SWIMS) has been designed to meet multi-agency hydrologic database needs for Kansas. The SWIMS project was supported...

  2. Summary of Meteorological Observations, Surface (SMOS) Beaufort, South Carolina.

    Science.gov (United States)

    1984-08-01

    7 * -i7 1- 371 > 1209 pq 7 1A1.0 ,38 9 uARY Of UEIEOROtOGICAL ORSERVAIIONS SURFACE ismos ) , IAU!OR! SOUtH CAROL INAIU) NAVAL OCEANOGRAPHY COUMANI...71.5 t k20M0 4 9. 77, 75, 77, 77. 7m*. ?903 l~ 790 to 11±. ?9: . c 80.3i P- S91oo 72.4 795 77 ITS T907 7961 79.( 796? 7900 790? 79.7 800 $063 IC. IsmO 1

  3. Biochemical characteristics and bacterial community structure of the sea surface microlayer in the South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    I. Obernosterer

    2007-08-01

    Full Text Available The chemical and biological characteristics of the surface microlayer were determined during a transect across the South Pacific Ocean in October-December 2004. Concentrations of particulate organic carbon (1.3 to 7.6-fold and nitrogen (1.4 to 7, and POC:PON ratios were consistently higher in the surface microlayer as compared to subsurface waters (5 m. The large variability in particulate organic matter enrichment was negatively correlated to wind speed. No enhanced concentrations of dissolved organic carbon were detectable in the surface microlayer as compared to 5 m, but chromophoric dissolved organic matter was markedly enriched (by 2 to 4-fold at all sites. Based on pigment analysis and cell counts, no consistent enrichment of any of the major components of the autotrophic and heterotrophic microbial community was detectable. CE-SSCP fingerprints and CARD FISH revealed that the bacterial communities present in the surface microlayer had close similarity (>76% to those in subsurface waters. By contrast, bacterial heterotrophic production (3H-leucine incorporation was consistently lower in the surface microlayer than in subsurface waters. By applying CARD-FISH and microautoradiography, we observed that Bacteroidetes and Gammaproteobacteria dominated leucine uptake in the surface microlayer, while in subsurface waters Bacteroidetes and Alphaproteobacteria were the major groups accounting for leucine incorporation. Our results demonstrate that the microbial community in the surface microlayer closely resembles that of the surface waters of the open ocean. However, even short time periods in the surface microlayer result in differences in bacterial groups accounting for leucine incorporation, probably as a response to the differences in the physical and chemical nature of the two layers.

  4. Surface-Water and Ground-Water Interactions in the Central Everglades, Florida

    Science.gov (United States)

    Harvey, Judson W.; Newlin, Jessica T.; Krest, James M.; Choi, Jungyill; Nemeth, Eric A.; Krupa, Steven L.

    2004-01-01

    Recharge and discharge are hydrological processes that cause Everglades surface water to be exchanged for subsurface water in the peat soil and the underlying sand and limestone aquifer. These interactions are thought to be important to water budgets, water quality, and ecology in the Everglades. Nonetheless, relatively few studies of surface water and ground water interactions have been conducted in the Everglades, especially in its vast interior areas. This report is a product of a cooperative investigation conducted by the USGS and the South Florida Water Management District (SFWMD) aimed at developing and testing techniques that would provide reliable estimates of recharge and discharge in interior areas of WCA-2A (Water Conservation Area 2A) and several other sites in the central Everglades. The new techniques quantified flow from surface water to the subsurface (recharge) and the opposite (discharge) using (1) Darcy-flux calculations based on measured vertical gradients in hydraulic head and hydraulic conductivity of peat; (2) modeling transport through peat and decay of the naturally occurring isotopes 224Ra and 223Ra (with half-lives of 4 and 11 days, respectively); and (3) modeling transport and decay of naturally occurring and 'bomb-pulse' tritium (half-life of 12.4 years) in ground water. Advantages and disadvantages of each method for quantifying recharge and discharge were compared. In addition, spatial and temporal variability of recharge and discharge were evaluated and controlling factors identified. A final goal was to develop appropriately simplified (that is, time averaged) expressions of the results that will be useful in addressing a broad range of hydrological and ecological problems in the Everglades. Results were compared with existing information about water budgets from the South Florida Water Management Model (SFWMM), a principal tool used by the South Florida Water Management District to plan many of the hydrological aspects of the

  5. The Dynamic Surface Tension of Water.

    Science.gov (United States)

    Hauner, Ines M; Deblais, Antoine; Beattie, James K; Kellay, Hamid; Bonn, Daniel

    2017-03-23

    The surface tension of water is an important parameter for many biological or industrial processes, and roughly a factor of 3 higher than that of nonpolar liquids such as oils, which is usually attributed to hydrogen bonding and dipolar interactions. Here we show by studying the formation of water drops that the surface tension of a freshly created water surface is even higher (∼90 mN m(-1)) than under equilibrium conditions (∼72 mN m(-1)) with a relaxation process occurring on a long time scale (∼1 ms). Dynamic adsorption effects of protons or hydroxides may be at the origin of this dynamic surface tension. However, changing the pH does not significantly change the dynamic surface tension. It also seems unlikely that hydrogen bonding or dipole orientation effects play any role at the relatively long time scale probed in the experiments.

  6. Water desorption from nanostructured graphite surfaces.

    Science.gov (United States)

    Clemens, Anna; Hellberg, Lars; Grönbeck, Henrik; Chakarov, Dinko

    2013-12-21

    Water interaction with nanostructured graphite surfaces is strongly dependent on the surface morphology. In this work, temperature programmed desorption (TPD) in combination with quadrupole mass spectrometry (QMS) has been used to study water ice desorption from a nanostructured graphite surface. This model surface was fabricated by hole-mask colloidal lithography (HCL) along with oxygen plasma etching and consists of a rough carbon surface covered by well defined structures of highly oriented pyrolytic graphite (HOPG). The results are compared with those from pristine HOPG and a rough (oxygen plasma etched) carbon surface without graphite nanostructures. The samples were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The TPD experiments were conducted for H2O coverages obtained after exposures between 0.2 and 55 langmuir (L) and reveal a complex desorption behaviour. The spectra from the nanostructured surface show additional, coverage dependent desorption peaks. They are assigned to water bound in two-dimensional (2D) and three-dimensional (3D) hydrogen-bonded networks, defect-bound water, and to water intercalated into the graphite structures. The intercalation is more pronounced for the nanostructured graphite surface in comparison to HOPG surfaces because of a higher concentration of intersheet openings. From the TPD spectra, the desorption energies for water bound in 2D and 3D (multilayer) networks were determined to be 0.32 ± 0.06 and 0.41 ± 0.03 eV per molecule, respectively. An upper limit for the desorption energy for defect-bound water was estimated to be 1 eV per molecule.

  7. Polyfluorinated chemicals in European surface waters, ground- and drinking waters

    NARCIS (Netherlands)

    Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

    2012-01-01

    Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during convention

  8. Polyfluorinated chemicals in European surface waters, ground- and drinking waters

    NARCIS (Netherlands)

    Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

    2012-01-01

    Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during

  9. Spreading of Cholera through Surface Water

    Science.gov (United States)

    Bertuzzo, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2009-12-01

    Cholera epidemics are still a major public health concern to date in many areas of the world. In order to understand and forecast cholera outbreaks, one of the most important factors is the role played by the environmental matrix in which the disease spreads. We study how river networks, acting as environmental corridors for pathogens, affect the spreading of cholera epidemics. The environmental matrix in which the disease spreads is constituted by different human communities and their hydrologic interconnections. Each community is characterized by its spatial position, population size, water resources availability and hygiene conditions. By implementing a spatially explicit cholera model we seek the effects on epidemic dynamics of: i) the topology and metrics of the pathogens pathways that connect different communities; ii) the spatial distribution of the population size; and iii) the spatial distributions and quality of surface water resources and public health conditions, and how they vary with population size. The model has been applied to study the space-time evolution of a well documented cholera epidemic occurred in the KwaZulu-Natal province of South Africa. The epidemic lasted for two years and involved about 140,000 confirmed cholera cases. The model does well in reproducing the distribution of the cholera cases during the two outbreaks as well as their spatial spreading. We further extend the model by deriving the speed of propagation of traveling fronts in the case of uniformly distributed systems for different topologies: one and two dimensional lattices and river networks. The derivation of the spreading celerity proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. The conditions are sought by comparison between spreading and disease timescales. Consider a cholera epidemic that starts from a point and spreads throughout a finite size system, it is possible to identify two different timescales: i

  10. Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports

    Science.gov (United States)

    Ooi, See Hai; Samah, Azizan Abu; Akbari, Abolghasem

    2016-01-01

    A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic currents while those in the southern areas are due solely to the wind stress because of negligible Coriolis force there. This study clearly shows that individual surface freshwater flux (evaporation minus precipitation) controls the sea salinity balance in the Southern South China Sea thermohaline circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China Sea, namely the Sunda Shelf and the Strait of Malacca. Apart from the above, in comparision with the dynamics of the Sunda Shelf, the Strait of Malacca reflects an equally significant role in the annual transports into the Andaman Sea. PMID:27410682

  11. Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports.

    Directory of Open Access Journals (Sweden)

    Farshid Daryabor

    Full Text Available A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic currents while those in the southern areas are due solely to the wind stress because of negligible Coriolis force there. This study clearly shows that individual surface freshwater flux (evaporation minus precipitation controls the sea salinity balance in the Southern South China Sea thermohaline circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China Sea, namely the Sunda Shelf and the Strait of Malacca. Apart from the above, in comparision with the dynamics of the Sunda Shelf, the Strait of Malacca reflects an equally significant role in the annual transports into the Andaman Sea.

  12. Delineation of areas having elevated electrical conductivity, orientation and characterization of bedrock fractures, and occurrence of groundwater discharge to surface water at the U.S. Environmental Protection Agency Barite Hill/Nevada Goldfields Superfund site near McCormick, South Carolina

    Science.gov (United States)

    Chapman, Melinda J.; Huffman, Brad A.; McSwain, Kristen Bukowski

    2015-07-16

    During October 2012 through March 2013, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (EPA) Region 4, Superfund Section, conducted borehole geophysical logging, surface geophysical surveys, and water-quality profiling in selected wells and areas to characterize or delineate the extent of elevated subsurface electrical conductivity at the EPA Barite Hill/Nevada Goldfields Superfund site near McCormick, South Carolina. Elevated electrical conductivity measured at the site may be related to native rock materials, waste rock disposal areas used in past operations, and (or) groundwater having elevated dissolved solids (primarily metals and major ions) related to waste migration. Five shallow screened wells and four open-borehole bedrock wells were logged by using a suite of borehole tools, and downhole water-quality profiles were recorded in two additional wells. Well depths ranged from about 26 to 300 feet below land surface. Surface geophysical surveys based on frequency-domain electromagnetic and distributed temperature sensing (DTS) techniques were used to identify areas of elevated electrical conductivity (Earth materials and groundwater) and potential high dissolved solids in groundwater and surface water on land and in areas along the northern unnamed tributary at the site.

  13. High-resolution hydraulic parameter maps for surface soils in tropical South America

    Science.gov (United States)

    Marthews, T. R.; Quesada, C. A.; Galbraith, D. R.; Malhi, Y.; Mullins, C. E.; Hodnett, M. G.; Dharssi, I.

    2014-05-01

    Modern land surface model simulations capture soil profile water movement through the use of soil hydraulics sub-models, but good hydraulic parameterisations are often lacking, especially in the tropics. We present much-improved gridded data sets of hydraulic parameters for surface soil for the critical area of tropical South America, describing soil profile water movement across the region to 30 cm depth. Optimal hydraulic parameter values are given for the Brooks and Corey, Campbell, van Genuchten-Mualem and van Genuchten-Burdine soil hydraulic models, which are widely used hydraulic sub-models in land surface models. This has been possible through interpolating soil measurements from several sources through the SOTERLAC soil and terrain data base and using the most recent pedotransfer functions (PTFs) derived for South American soils. All soil parameter data layers are provided at 15 arcsec resolution and available for download, this being 20x higher resolution than the best comparable parameter maps available to date. Specific examples are given of the use of PTFs and the importance highlighted of using PTFs that have been locally parameterised and that are not just based on soil texture. We discuss current developments in soil hydraulic modelling and how high-resolution parameter maps such as these can improve the simulation of vegetation development and productivity in land surface models.

  14. Lunar South Pole space water extraction and trucking system

    Energy Technology Data Exchange (ETDEWEB)

    Zuppero, A. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.]|[Univ. of Idaho, Moscow, ID (United States); Zupp, G. [National Aeronautics and Space Administration, Houston, TX (United States). Johnson Space Center; Schnitzler, B.; Larson, T.K.; Rice, J.W. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.

    1998-03-01

    This concept proposes to use thermal processes alone to extract water from the lunar South Pole and launch payloads to low lunar orbit. Thermal steam rockets would use water propellant for space transportation. The estimated mass of a space water tanker powered by a nuclear heated steam rocket suggests it can be designed for launch in the Space Shuttle bay. The performance depends on the feasibility of a nuclear reactor rocket engine producing steam at 1,100 degrees Kelvin, with a power density of 150 Megawatts per ton of rocket, and operating for thousands of 20 minute cycles. An example uses reject heat from a small nuclear electric power supply to melt 17,800 tons per year of lunar ice. A nuclear heated steam rocket would use the propellant water to launch and deliver 3,800 tons of water per year to a 100 km low lunar orbit.

  15. Identifying Surface Changes on HRSC Images of the Mars South Polar Residual CAP (sprc)

    Science.gov (United States)

    Putri, Alfiah Rizky Diana; Sidiropoulos, Panagiotis; Muller, Jan-Peter

    2016-06-01

    The surface of Mars has been an object of interest for planetary research since the launch of Mariner 4 in 1964. Since then different cameras such as the Viking Visual Imaging Subsystem (VIS), Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), and Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) and High Resolution Imaging Science Experiment (HiRISE) have been imaging its surface at ever higher resolution. The High Resolution Stereo Camera (HRSC) on board of the European Space Agency (ESA) Mars Express, has been imaging the Martian surface, since 25th December 2003 until the present-day. HRSC has covered 100 % of the surface of Mars, about 70 % of the surface with panchromatic images at 10-20 m/pixel, and about 98 % at better than 100 m/pixel (Neukum et. al., 2004), including the polar regions of Mars. The Mars polar regions have been studied intensively recently by analysing images taken by the Mars Express and MRO missions (Plaut et al., 2007). The South Polar Residual Cap (SPRC) does not change very much in volume overall but there are numerous examples of dynamic phenomena associated with seasonal changes in the atmosphere. In particular, we can examine the time variation of layers of solid carbon dioxide and water ice with dust deposition (Bibring, 2004), spider-like channels (Piqueux et al., 2003) and so-called Swiss Cheese Terrain (Titus et al., 2004). Because of seasonal changes each Martian year, due to the sublimation and deposition of water and CO2 ice on the Martian south polar region, clearly identifiable surface changes occur in otherwise permanently icy region. In this research, good quality HRSC images of the Mars South Polar region are processed based on previous identification as the optimal coverage of clear surfaces (Campbell et al., 2015). HRSC images of the Martian South Pole are categorized in terms of quality, time, and location to find overlapping areas, processed into high quality Digital Terrain Models (DTMs) and

  16. IDENTIFYING SURFACE CHANGES ON HRSC IMAGES OF THE MARS SOUTH POLAR RESIDUAL CAP (SPRC

    Directory of Open Access Journals (Sweden)

    A. R. D. Putri

    2016-06-01

    Full Text Available The surface of Mars has been an object of interest for planetary research since the launch of Mariner 4 in 1964. Since then different cameras such as the Viking Visual Imaging Subsystem (VIS, Mars Global Surveyor (MGS Mars Orbiter Camera (MOC, and Mars Reconnaissance Orbiter (MRO Context Camera (CTX and High Resolution Imaging Science Experiment (HiRISE have been imaging its surface at ever higher resolution. The High Resolution Stereo Camera (HRSC on board of the European Space Agency (ESA Mars Express, has been imaging the Martian surface, since 25th December 2003 until the present-day. HRSC has covered 100 % of the surface of Mars, about 70 % of the surface with panchromatic images at 10-20 m/pixel, and about 98 % at better than 100 m/pixel (Neukum et. al., 2004, including the polar regions of Mars. The Mars polar regions have been studied intensively recently by analysing images taken by the Mars Express and MRO missions (Plaut et al., 2007. The South Polar Residual Cap (SPRC does not change very much in volume overall but there are numerous examples of dynamic phenomena associated with seasonal changes in the atmosphere. In particular, we can examine the time variation of layers of solid carbon dioxide and water ice with dust deposition (Bibring, 2004, spider-like channels (Piqueux et al., 2003 and so-called Swiss Cheese Terrain (Titus et al., 2004. Because of seasonal changes each Martian year, due to the sublimation and deposition of water and CO2 ice on the Martian south polar region, clearly identifiable surface changes occur in otherwise permanently icy region. In this research, good quality HRSC images of the Mars South Polar region are processed based on previous identification as the optimal coverage of clear surfaces (Campbell et al., 2015. HRSC images of the Martian South Pole are categorized in terms of quality, time, and location to find overlapping areas, processed into high quality Digital Terrain Models (DTMs and

  17. Stable water layers on solid surfaces.

    Science.gov (United States)

    Hong, Ying-Jhan; Tai, Lin-Ai; Chen, Hung-Jen; Chang, Pin; Yang, Chung-Shi; Yew, Tri-Rung

    2016-02-17

    Liquid layers adhered to solid surfaces and that are in equilibrium with the vapor phase are common in printing, coating, and washing processes as well as in alveoli in lungs and in stomata in leaves. For such a liquid layer in equilibrium with the vapor it faces, it has been generally believed that, aside from liquid lumps, only a very thin layer of the liquid, i.e., with a thickness of only a few nanometers, is held onto the surface of the solid, and that this adhesion is due to van der Waals forces. A similar layer of water can remain on the surface of a wall of a microchannel after evaporation of bulk water creates a void in the channel, but the thickness of such a water layer has not yet been well characterized. Herein we showed such a water layer adhered to a microchannel wall to be 100 to 170 nm thick and stable against surface tension. The water layer thickness was measured using electron energy loss spectroscopy (EELS), and the water layer structure was characterized by using a quantitative nanoparticle counting technique. This thickness was found for channel gap heights ranging from 1 to 5 μm. Once formed, the water layers in the microchannel, when sealed, were stable for at least one week without any special care. Our results indicate that the water layer forms naturally and is closely associated only with the surface to which it adheres. Our study of naturally formed, stable water layers may shed light on topics from gas exchange in alveoli in biology to the post-wet-process control in the semiconductor industry. We anticipate our report to be a starting point for more detailed research and understanding of the microfluidics, mechanisms and applications of gas-liquid-solid systems.

  18. Water footprint assessment to inform water management and policy making in South Africa

    NARCIS (Netherlands)

    Pahlow, M.; Snowball, J.; Fraser, G.

    2015-01-01

    One method to inform decisions with respect to sustainable, efficient and equitable water allocation and use is water footprint assessment (WFA). This paper presents a preliminary WFA of South Africa (SA) based on data for the period 1996–2005. Crop production was found to contribute about 75% of th

  19. Radiolysis of water with aluminum oxide surfaces

    Science.gov (United States)

    Reiff, Sarah C.; LaVerne, Jay A.

    2017-02-01

    Aluminum oxide, Al2O3, nanoparticles with water were irradiated with γ-rays and 5 MeV He ions followed by the determination of the production of molecular hydrogen, H2, and characterization of changes in the particle surface. Surface analysis techniques included: diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), nitrogen absorption with the Brunauer - Emmett - Teller (BET) methodology for surface area determination, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Production of H2 by γ-ray radiolysis was determined for samples with adsorbed water and for Al2O3 - water slurries. For Al2O3 samples with adsorbed water, the radiation chemical yield of H2 was measured as 80±20 molecules/100 eV (1 molecule/100 eV=1.04×10-7 mol/J). The yield of H2 was observed to decrease as the amount of water present in the Al2O3 - water slurries increased. Surface studies indicated that the α-phase Al2O3 samples changed phase following irradiation by He ions, and that the oxyhydroxide layer, present on the pristine sample, is removed by γ-ray and He ion irradiation.

  20. Water vapor interactions with polycrystalline titanium surfaces

    Science.gov (United States)

    Azoulay, A.; Shamir, N.; Volterra, V.; Mintz, M. H.

    1999-02-01

    The initial interactions of water vapor with polycrystalline titanium surfaces were studied at room temperature. Measurements of water vapor surface accumulation were performed in a combined surface analysis system incorporating direct recoils spectrometry (DRS), Auger electron spectroscopy and X-ray photoelectron spectroscopy. The kinetics of accommodation of the water dissociation fragments (H, O and OH) displayed a complex behavior depending not only on the exposure dose but also on the exposure pressure. For a given exposure dose the efficiency of chemisorption increased with increasing exposure pressure. DRS measurements indicated the occurrence of clustered hydroxyl moieties with tilted O-H bonds formed even at very low surface coverage. A model which assumes two parallel routes of chemisorption, by direct collisions (Langmuir type) and by a precursor state is proposed to account for the observed behavior. The oxidation efficiency of water seemed to be much lower than that of oxygen. No Ti 4+ states were detected even at high water exposure values. It is likely that hydroxyl species play an important role in the reduced oxidation efficiency of water.

  1. A Water Rich Mars Surface Mission Scenario

    Science.gov (United States)

    Hoffman, Stephen; Andrews, Alida; Joosten, Kent; Watts, Kevin

    2017-01-01

    The surface of Mars once had abundant water flowing on its surface, but now there is a general perception that this surface is completely dry. Several lines of research have shown that there are sources of potentially large quantities of water at many locations on the surface, including regions considered as candidates for future human missions. Traditionally, system designs for these human missions are constrained to tightly recycle water and oxygen, and current resource utilization strategies involve ascent vehicle oxidizer production only. But the assumption of relatively abundant extant water may change this. Several scenarios were constructed to evaluate water requirements for human Mars expeditions to assess the impact to system design if locally produced water is available. Specifically, we have assessed water resources needed for 1) ascent vehicle oxidizer and fuel production, 2) open-loop water and oxygen life support requirements along with more robust usage scenarios, and 3) crew radiation protection augmentation. In this assessment, production techniques and the associated chemistry to transform Martian water and atmosphere into these useful commodities are identified, but production mass and power requirements are left to future analyses. The figure below illustrates the type of water need assessment performed and that will be discussed. There have been several sources of feedstock material discussed in recent literature that could be used to produce these quantities of water. This paper will focus on Mars surface features that resemble glacier-like forms on Earth. Several lines of evidence indicate that some of these features are in fact buried ice, likely remnants from an earlier ice age on Mars. This paper examines techniques and hardware systems used in the polar regions of Earth to access this buried ice and withdraw water from it. These techniques and systems will be described to illustrate options available. A technique known as a Rodriguez Well

  2. Assuming too much? Participatory water resource governance in South Africa.

    Science.gov (United States)

    Brown, Julia

    2011-01-01

    This paper argues that participation in natural resource management, which is often coupled with moves for more local ownership of decision making, is based on three sets of assumptions: about the role of the state, the universality of application of such approaches and the transformatory potential of institutional reform. The validity of these assumptions requires investigation in view of the rapid institutionalisation and scaling-up of participatory approaches, particularly in developing country contexts. Post-apartheid South Africa is widely recognised as a pioneer of participatory and devolutionary approaches, particularly in the field of water resources. It is 12 years since the promulgation of the forward-thinking 1998 National Water Act, and thus an opportune moment to reflect on South Africa's experiences of participatory governance. Drawing on empirical research covering the establishment of the first Catchment Management Agency, and the transformation of existing Irrigation Boards into more inclusive Water User Associations in the Inkomati Water Management Area, it emerges that there may be fundamental weaknesses in the participatory model and underlying assumptions, and indeed such approaches may actually reinforce inequitable outcomes: the legacy of long-established institutional frameworks and powerful actors therein continues to exert influence in post-apartheid South Africa, and has the potential to subvert the democratic and redistributive potential of the water reforms. It is argued that a reassessment of the role of the state is necessary: where there is extreme heterogeneity in challenging catchments more, rather than less, state intervention may be required to uphold the interests of marginalised groups and effect redistribution.

  3. Benthic flux of dissolved nickel into the water column of south San Francisco Bay

    Science.gov (United States)

    Topping, B.R.; Kuwabara, J.S.; Parcheso, Francis; Hager, S.W.; Arnsberg, A.J.; Murphy, Fred

    2001-01-01

    Field and laboratory studies were conducted between April, 1998 and May, 1999 to provide the first direct measurements of the benthic flux of dissolved (0.2-micron filtered) nickel between the bottom sediment and water column at three sites in the southern component of San Francisco Bay (South Bay), California. Dissolved nickel and predominant ligands (represented by dissolved organic carbon, and sulfides) were the solutes of primary interest, although a variety of ancillary measurements were also performed to provide a framework for interpretation. Results described herein integrate information needs identified by the State Water Resources Control Board and local stakeholders with fundamental research associated with the U.S. Geological Survey Toxic Substances Hydrology Program. Dissolved-Ni concentrations in the bottom water over the three sampling dates ranged from 34 to 43 nanomoles per liter. Dissolved-macronutrient concentrations in the bottom water were consistently higher (frequently by orders of magnitude) than surface-water determinations reported for similar times and locations (Regional Monitoring Program, 2001). This is consistent with measured positive benthic fluxes for the macronutrients. Benthic-flux estimates for dissolved nickel from core-incubations, when areally averaged over the South Bay, were significant (that is, of equivalent or greater order of magnitude) relative to previously reported freshwater point and non-point sources. This observation is consistent with previous determinations for other metals, and with the potential remobilization of sediment-associated metals that have been ubiquitously distributed in the South Bay. Similar to dissolved-nickel results, benthic flux of macronutrients was also consistently significant relative to surface-water inputs. These results add to a growing body of knowledge that strongly suggests a need to consider contaminant transport across the sediment-water interface when establishing future

  4. Electrolysis of water on (oxidized) metal surfaces

    DEFF Research Database (Denmark)

    Rossmeisl, Jan; Logadottir, Ashildur; Nørskov, Jens Kehlet

    2005-01-01

    directly from the electronic structure calculations. We consider electrodes of Pt(111) and Au(111) in detail and then discuss trends for a series of different metals. We show that the difficult step in the water splitting process is the formation of superoxy-type (OOH) species on the surface...... by the splitting of a water molecule on top an adsorbed oxygen atom. One conclusion is that this is only possible on metal surfaces that are (partly) oxidized. We show that the binding energies of the different intermediates are linearly correlated for a number of metals. In a simple analysis, where the linear...... relations are assumed to be obeyed exactly, this leads to a universal relationship between the catalytic rate and the oxygen binding energy. Finally, we conclude that for systems obeying these relations, there is a limit to how good a water splitting catalyst an oxidized metal surface can become. (c) 2005...

  5. Deep South Atlantic carbonate chemistry and increased interocean deep water exchange during last deglaciation

    Science.gov (United States)

    Yu, Jimin; Anderson, Robert F.; Jin, Zhangdong; Menviel, Laurie; Zhang, Fei; Ryerson, Fredrick J.; Rohling, Eelco J.

    2014-04-01

    Carbon release from the deep ocean at glacial terminations is a critical component of past climate change, but the underlying mechanisms remain poorly understood. We present a 28,000-year high-resolution record of carbonate ion concentration, a key parameter of the global carbon cycle, at 5-km water depth in the South Atlantic. We observe similar carbonate ion concentrations between the Last Glacial Maximum and the late Holocene, despite elevated concentrations in the glacial surface ocean. This strongly supports the importance of respiratory carbon accumulation in a stratified deep ocean for atmospheric CO2 reduction during the last ice age. After ˜9 μmol/kg decline during Heinrich Stadial 1, deep South Atlantic carbonate ion concentration rose by ˜24 μmol/kg from the onset of Bølling to Pre-boreal, likely caused by strengthening North Atlantic Deep Water formation (Bølling) or increased ventilation in the Southern Ocean (Younger Drays) or both (Pre-boreal). The ˜15 μmol/kg decline in deep water carbonate ion since ˜10 ka is consistent with extraction of alkalinity from seawater by deep-sea CaCO3 compensation and coral reef growth on continental shelves during the Holocene. Between 16,600 and 15,000 years ago, deep South Atlantic carbonate ion values converged with those at 3.4-km water depth in the western equatorial Pacific, as did carbon isotope and radiocarbon values. These observations suggest a period of enhanced lateral exchange of carbon between the deep South Atlantic and Pacific Oceans, probably due to an increased transfer of momentum from southern westerlies to the Southern Ocean. By spreading carbon-rich deep Pacific waters around Antarctica for upwelling, invigorated interocean deep water exchange would lead to more efficient CO2 degassing from the Southern Ocean, and thus to an atmospheric CO2 rise, during the early deglaciation.

  6. Surface Modification of Water Purification Membranes.

    Science.gov (United States)

    Miller, Daniel J; Dreyer, Daniel R; Bielawski, Christopher W; Paul, Donald R; Freeman, Benny D

    2017-04-18

    Polymeric membranes are an energy-efficient means of purifying water, but they suffer from fouling during filtration. Modification of the membrane surface is one route to mitigating membrane fouling, as it helps to maintain high levels of water productivity. Here, a series of common techniques for modification of the membrane surface are reviewed, including surface coating, grafting, and various treatment techniques such as chemical treatment, UV irradiation, and plasma treatment. Historical background on membrane development and surface modification is also provided. Finally, polydopamine, an emerging material that can be easily deposited onto a wide variety of substrates, is discussed within the context of membrane modification. A brief summary of the chemistry of polydopamine, particularly as it may pertain to membrane development, is also described. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Surface Water Protection by Productive Buffers

    DEFF Research Database (Denmark)

    Christen, Benjamin

    Vegetated riparian buffer zones are a widely recommended best management practice in agriculture for protecting surface and coastal waters from diffuse nutrient pollution. On the background of the EU funded research project NitroEurope (NEU; www.NitroEurope.eu), this study concentrates...... on the mitigation of nitrogen pollution in surface and groundwater, using riparian buffer zones for biomass production. The objectives are to map suitable areas for buffer implementation across the six NEU study landscapes, model tentative N-loss mitigation, calculate biomass production potential and economic...... designed for local conditions could be a way of protecting water quality attractive to many stakeholders....

  8. Transient surface liquid in Titan's south polar region from Cassini

    Science.gov (United States)

    Hayes, A.G.; Aharonson, O.; Lunine, J.I.; Kirk, R.L.; Zebker, H.A.; Wye, L.C.; Lorenz, R.D.; Turtle, E.P.; Paillou, P.; Mitri, Giuseppe; Wall, S.D.; Stofan, E.R.; Mitchell, K.L.; Elachi, C.

    2011-01-01

    Cassini RADAR images of Titan's south polar region acquired during southern summer contain lake features which disappear between observations. These features show a tenfold increases in backscatter cross-section between images acquired one year apart, which is inconsistent with common scattering models without invoking temporal variability. The morphologic boundaries are transient, further supporting changes in lake level. These observations are consistent with the exposure of diffusely scattering lakebeds that were previously hidden by an attenuating liquid medium. We use a two-layer model to explain backscatter variations and estimate a drop in liquid depth of approximately 1-m-per-year. On larger scales, we observe shoreline recession between ISS and RADAR images of Ontario Lacus, the largest lake in Titan's south polar region. The recession, occurring between June 2005 and July 2009, is inversely proportional to slopes estimated from altimetric profiles and the exponential decay of near-shore backscatter, consistent with a uniform reduction of 4 ± 1.3 m in lake depth. Of the potential explanations for observed surface changes, we favor evaporation and infiltration. The disappearance of dark features and the recession of Ontario's shoreline represents volatile transport in an active methane-based hydrologic cycle. Observed loss rates are compared and shown to be consistent with available global circulation models. To date, no unambiguous changes in lake level have been observed between repeat images in the north polar region, although further investigation is warranted. These observations constrain volatile flux rates in Titan's hydrologic system and demonstrate that the surface plays an active role in its evolution. Constraining these seasonal changes represents the first step toward our understanding of longer climate cycles that may determine liquid distribution on Titan over orbital time periods.

  9. Integrating remotely sensed surface water extent into continental scale hydrology.

    Science.gov (United States)

    Revilla-Romero, Beatriz; Wanders, Niko; Burek, Peter; Salamon, Peter; de Roo, Ad

    2016-12-01

    In hydrological forecasting, data assimilation techniques are employed to improve estimates of initial conditions to update incorrect model states with observational data. However, the limited availability of continuous and up-to-date ground streamflow data is one of the main constraints for large-scale flood forecasting models. This is the first study that assess the impact of assimilating daily remotely sensed surface water extent at a 0.1° × 0.1° spatial resolution derived from the Global Flood Detection System (GFDS) into a global rainfall-runoff including large ungauged areas at the continental spatial scale in Africa and South America. Surface water extent is observed using a range of passive microwave remote sensors. The methodology uses the brightness temperature as water bodies have a lower emissivity. In a time series, the satellite signal is expected to vary with changes in water surface, and anomalies can be correlated with flood events. The Ensemble Kalman Filter (EnKF) is a Monte-Carlo implementation of data assimilation and used here by applying random sampling perturbations to the precipitation inputs to account for uncertainty obtaining ensemble streamflow simulations from the LISFLOOD model. Results of the updated streamflow simulation are compared to baseline simulations, without assimilation of the satellite-derived surface water extent. Validation is done in over 100 in situ river gauges using daily streamflow observations in the African and South American continent over a one year period. Some of the more commonly used metrics in hydrology were calculated: KGE', NSE, PBIAS%, R(2), RMSE, and VE. Results show that, for example, NSE score improved on 61 out of 101 stations obtaining significant improvements in both the timing and volume of the flow peaks. Whereas the validation at gauges located in lowland jungle obtained poorest performance mainly due to the closed forest influence on the satellite signal retrieval. The conclusion is that

  10. Integrating remotely sensed surface water extent into continental scale hydrology

    Science.gov (United States)

    Revilla-Romero, Beatriz; Wanders, Niko; Burek, Peter; Salamon, Peter; de Roo, Ad

    2016-12-01

    In hydrological forecasting, data assimilation techniques are employed to improve estimates of initial conditions to update incorrect model states with observational data. However, the limited availability of continuous and up-to-date ground streamflow data is one of the main constraints for large-scale flood forecasting models. This is the first study that assess the impact of assimilating daily remotely sensed surface water extent at a 0.1° × 0.1° spatial resolution derived from the Global Flood Detection System (GFDS) into a global rainfall-runoff including large ungauged areas at the continental spatial scale in Africa and South America. Surface water extent is observed using a range of passive microwave remote sensors. The methodology uses the brightness temperature as water bodies have a lower emissivity. In a time series, the satellite signal is expected to vary with changes in water surface, and anomalies can be correlated with flood events. The Ensemble Kalman Filter (EnKF) is a Monte-Carlo implementation of data assimilation and used here by applying random sampling perturbations to the precipitation inputs to account for uncertainty obtaining ensemble streamflow simulations from the LISFLOOD model. Results of the updated streamflow simulation are compared to baseline simulations, without assimilation of the satellite-derived surface water extent. Validation is done in over 100 in situ river gauges using daily streamflow observations in the African and South American continent over a one year period. Some of the more commonly used metrics in hydrology were calculated: KGE', NSE, PBIAS%, R2, RMSE, and VE. Results show that, for example, NSE score improved on 61 out of 101 stations obtaining significant improvements in both the timing and volume of the flow peaks. Whereas the validation at gauges located in lowland jungle obtained poorest performance mainly due to the closed forest influence on the satellite signal retrieval. The conclusion is that

  11. Surface-Water Conditions in Georgia, Water Year 2005

    Science.gov (United States)

    Painter, Jaime A.; Landers, Mark N.

    2007-01-01

    INTRODUCTION The U.S. Geological Survey (USGS) Georgia Water Science Center-in cooperation with Federal, State, and local agencies-collected surface-water streamflow, water-quality, and ecological data during the 2005 Water Year (October 1, 2004-September 30, 2005). These data were compiled into layers of an interactive ArcReaderTM published map document (pmf). ArcReaderTM is a product of Environmental Systems Research Institute, Inc (ESRI?). Datasets represented on the interactive map are * continuous daily mean streamflow * continuous daily mean water levels * continuous daily total precipitation * continuous daily water quality (water temperature, specific conductance dissolved oxygen, pH, and turbidity) * noncontinuous peak streamflow * miscellaneous streamflow measurements * lake or reservoir elevation * periodic surface-water quality * periodic ecological data * historical continuous daily mean streamflow discontinued prior to the 2005 water year The map interface provides the ability to identify a station in spatial reference to the political boundaries of the State of Georgia and other features-such as major streams, major roads, and other collection stations. Each station is hyperlinked to a station summary showing seasonal and annual stream characteristics for the current year and for the period of record. For continuous discharge stations, the station summary includes a one page graphical summary page containing five graphs, a station map, and a photograph of the station. The graphs provide a quick overview of the current and period-of-record hydrologic conditions of the station by providing a daily mean discharge graph for the water year, monthly statistics graph for the water year and period of record, an annual mean streamflow graph for the period of record, an annual minimum 7-day average streamflow graph for the period of record, and an annual peak streamflow graph for the period of record. Additionally, data can be accessed through the layer's link

  12. The internet of things in water resources management for South Africa

    CSIR Research Space (South Africa)

    Dlodlo, N

    2015-12-01

    Full Text Available This paper reports on potential applications of IoT technologies that could contribute to water resource management in South Africa. The authors visited South Africa’s Department of Water and Sanitation website and the South African government...

  13. 75 FR 30013 - South Feather Water and Power Agency; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2010-05-28

    ... Energy Regulatory Commission South Feather Water and Power Agency; Notice of Availability of...), Commission staff has prepared an environmental assessment (EA) regarding South Feather Water and Power Agency... Creek development of the South Feather Power Project (FERC No. 2088). Sly Creek is located on Sly...

  14. Transport of North Pacific 137Cs labeled waters to the south-eastern Atlantic Ocean

    Science.gov (United States)

    Sanchez-Cabeza, J. A.; Levy, I.; Gastaud, J.; Eriksson, M.; Osvath, I.; Aoyama, M.; Povinec, P. P.; Komura, K.

    2011-04-01

    During the reoccupation of the WOCE transect A10 at 30°S by the BEAGLE2003 cruise, the SHOTS project partners collected a large number of samples for the analysis of isotopic tracers. 137Cs was mostly deposited on the oceans surface during the late 1950s and early 1960s, after the atmospheric detonation of large nuclear devices, which mostly occurred in the Northern Hemisphere. The development of advanced radioanalytical and counting techniques allowed to obtain, for the first time in this region, a zonal section of 137Cs water concentrations, where little information existed before, thus constituting an important benchmark for further studies. 137Cs concentrations in the upper waters (0-1000 m) of the south-eastern Atlantic Ocean are similar to those observed in the south-western Indian Ocean, suggesting transport of 137Cs labeled waters by the Agulhas current to the Benguela Current region. In contrast, bomb radiocarbon data do not show this feature, indicating the usefulness of 137Cs as a radiotracer of water mass transport from the Indian to the South Atlantic Ocean.

  15. Ultra Water Repellent Polypropylene Surfaces with Tunable Water Adhesion.

    Science.gov (United States)

    Zhu, Tang; Cai, Chao; Guo, Jing; Wang, Rong; Zhao, Ning; Xu, Jian

    2017-03-22

    Polypropylene (PP), including isotactic PP (i-PP) and atactic PP (a-PP) with distinct tacticity, is one of the most widely used general plastics. Herein, ultra water repellent PP coatings with tunable adhesion to water were prepared via a simple casting method. The pure i-PP coating shows a hierarchical morphology with micro/nanobinary structures, exhibiting a water contact angle (CA) larger than 150° and a sliding angle less than 5° (for 5 μL water droplet). In contrast, the pure a-PP coating has a less rough morphology with a water contact angle of about 130°, and the water droplets stick on the coating at any tilted angles. For the composite i-PP/a-PP coatings, however, ultra water repellency with CA > 150° but water adhesion tailorable from slippery to sticky can be realized, depending on the contents of a-PP and i-PP. The different wetting behaviors are due to the various microstructures of the composite coatings resulting from the distinct crystallization ability of a-PP and i-PP. Furthermore, the existence of a-PP in the composite coatings enhances the mechanical properties compared to the i-PP coating. The proposed method is feasible to modify various substrates and potential applications in no-loss liquid transportation, slippery surfaces, and patterned superhydrophobic surfaces are demonstrated.

  16. Global modelling of Cryptosporidium in surface water

    Science.gov (United States)

    Vermeulen, Lucie; Hofstra, Nynke

    2016-04-01

    Introduction Waterborne pathogens that cause diarrhoea, such as Cryptosporidium, pose a health risk all over the world. In many regions quantitative information on pathogens in surface water is unavailable. Our main objective is to model Cryptosporidium concentrations in surface waters worldwide. We present the GloWPa-Crypto model and use the model in a scenario analysis. A first exploration of global Cryptosporidium emissions to surface waters has been published by Hofstra et al. (2013). Further work has focused on modelling emissions of Cryptosporidium and Rotavirus to surface waters from human sources (Vermeulen et al 2015, Kiulia et al 2015). A global waterborne pathogen model can provide valuable insights by (1) providing quantitative information on pathogen levels in data-sparse regions, (2) identifying pathogen hotspots, (3) enabling future projections under global change scenarios and (4) supporting decision making. Material and Methods GloWPa-Crypto runs on a monthly time step and represents conditions for approximately the year 2010. The spatial resolution is a 0.5 x 0.5 degree latitude x longitude grid for the world. We use livestock maps (http://livestock.geo-wiki.org/) combined with literature estimates to calculate spatially explicit livestock Cryptosporidium emissions. For human Cryptosporidium emissions, we use UN population estimates, the WHO/UNICEF JMP sanitation country data and literature estimates of wastewater treatment. We combine our emissions model with a river routing model and data from the VIC hydrological model (http://vic.readthedocs.org/en/master/) to calculate concentrations in surface water. Cryptosporidium survival during transport depends on UV radiation and water temperature. We explore pathogen emissions and concentrations in 2050 with the new Shared Socio-economic Pathways (SSPs) 1 and 3. These scenarios describe plausible future trends in demographics, economic development and the degree of global integration. Results and

  17. North Inlet-Winyah Bay National Estuarine Research Reserve’s (NERR) Estuarine Surface Water Nutrient, Suspended Sediment, and Chlorophyll a Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 2002-2004

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — National Estuarine Research Reserve System The National Estuarine Research Reserve System was established by the Coastal Zone Management Act of 1972 (as amended) and...

  18. Lithium content in potable water, surface water, ground water, and mineral water on the territory of Republic of Macedonia

    OpenAIRE

    Vesna Kostik; Biljana Bauer; Zoran Kavrakovski

    2014-01-01

    The aim of this study was to determine lithium concentration in potable water, surface water, ground, and mineral water on the territory of the Republic of Macedonia. Water samples were collected from water bodies such as multiple public water supply systems located in 13 cities, wells boreholes located in 12 areas, lakes and rivers located in three different areas. Determination of lithium concentration in potable water, surface water was performed by the technique of inductively coupl...

  19. Thermodynamic properties of water solvating biomolecular surfaces

    Science.gov (United States)

    Heyden, Matthias

    Changes in the potential energy and entropy of water molecules hydrating biomolecular interfaces play a significant role for biomolecular solubility and association. Free energy perturbation and thermodynamic integration methods allow calculations of free energy differences between two states from simulations. However, these methods are computationally demanding and do not provide insights into individual thermodynamic contributions, i.e. changes in the solvent energy or entropy. Here, we employ methods to spatially resolve distributions of hydration water thermodynamic properties in the vicinity of biomolecular surfaces. This allows direct insights into thermodynamic signatures of the hydration of hydrophobic and hydrophilic solvent accessible sites of proteins and small molecules and comparisons to ideal model surfaces. We correlate dynamic properties of hydration water molecules, i.e. translational and rotational mobility, to their thermodynamics. The latter can be used as a guide to extract thermodynamic information from experimental measurements of site-resolved water dynamics. Further, we study energy-entropy compensations of water at different hydration sites of biomolecular surfaces. This work is supported by the Cluster of Excellence RESOLV (EXC 1069) funded by the Deutsche Forschungsgemeinschaft.

  20. Impinging Water Droplets on Inclined Glass Surfaces.

    Energy Technology Data Exchange (ETDEWEB)

    Armijo, Kenneth Miguel; Lance, Blake; Ho, Clifford K.

    2017-09-01

    Multiphase computational models and tests of falling water droplets on inclined glass surfaces were developed to investigate the physics of impingement and potential of these droplets to self-clean glass surfaces for photovoltaic modules and heliostats. A multiphase volume-of-fluid model was developed in ANSYS Fluent to simulate the impinging droplets. The simulations considered different droplet sizes (1 mm and 3 mm), tilt angles (0deg, 10deg, and 45deg), droplet velocities (1 m/s and 3 m/s), and wetting characteristics (wetting=47deg contact angle and non-wetting = 93deg contact angle). Results showed that the spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) decreased with increasing inclination angle due to the reduced normal force on the surface. The hydrophilic surface yielded greater spread factors than the hydrophobic surface in all cases. With regard to impact forces, the greater surface tilt angles yielded lower normal forces, but higher shear forces. Experiments showed that the experimentally observed spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) was significantly larger than the simulated spread factor. Observed spread factors were on the order of 5 - 6 for droplet velocities of %7E3 m/s, whereas the simulated spread factors were on the order of 2. Droplets were observed to be mobile following impact only for the cases with 45deg tilt angle, which matched the simulations. An interesting phenomenon that was observed was that shortly after being released from the nozzle, the water droplet oscillated (like a trampoline) due to the "snapback" caused by the surface tension of the water droplet being released from the nozzle. This oscillation impacted the velocity immediately after the release. Future work should evaluate the impact of parameters such as tilt angle and surface wettability on the impact of particle/soiling uptake and removal to investigate ways that

  1. Regionalized Lunar South Pole Surface Navigation System Analysis

    Directory of Open Access Journals (Sweden)

    Bryan W. Welch

    2008-01-01

    Full Text Available Apollo missions utilized Earth-based assets for navigation, since the landings took place at lunar locations in constant view from the Earth. The new exploration campaign to the lunar South Pole region will have limited Earth visibility, but the extent to which a navigation system comprised solely of Earth-based tracking stations will provide adequate navigation solutions in this region is unknown. This article presents a dilution-of-precision-(DoP- based stationary surface navigation analysis of the performance of multiple lunar satellite constellations, Earth-based deep space network assets, and combinations thereof. Results show that kinematic and integrated solutions cannot be provided by the Earth-based deep space network stations. Also, the surface stationary navigation system needs to be operated as a two-way navigation system, or as a one-way navigation system with local terrain information, while integrating the position solution over a short duration of time with navigation signals being provided by a lunar satellite constellation.

  2. Soil heat flux and day time surface energy balance closure at astronomical observatory, Thiruvananthapuram, south Kerala

    Indian Academy of Sciences (India)

    M S Roxy; V B Sumithranand; G Renuka

    2014-06-01

    Soil heat flux is an important input component of surface energy balance. Estimates of soil heat flux were made in the year 2008 using soil temperature data at Astronomical Observatory, Thiruvananthapuram, south Kerala. Hourly values of soil heat flux from 00 to 24 LST are presented for selected days typical of the winter, pre-monsoon, SW monsoon and NE monsoon seasons. The diurnal variation is characterized by a cross-over from negative to positive values at 0700 h, occurrence of maximum around noon and return to negative values in the late evening. The energy storage term for the soil layer 0–0.05 m is calculated and the ground heat flux * is estimated in all seasons. Daytime surface energy balance at the surface on wet and dry seasons is investigated. The average Bowen’s ratio during the wet and dry seasons were 0.541 and 0.515, respectively indicating that considerable evaporation takes place at the surface. The separate energy balance components were examined and the mean surface energy balance closure was found to be 0.742 and 0.795 for wet and dry seasons, respectively. When a new method that accounts for both soil thermal conduction and soil thermal convection was adopted to calculate the surface heat flux, the energy balance closure was found to be improved. Thus on the land surface under study, the soil vertical water movement is significant.

  3. Water quality criteria for the South African coastal zone

    CSIR Research Space (South Africa)

    Lusher, JA

    1984-12-01

    Full Text Available by the Foundation for Research Development Council for Scientific and Industrial Research P 0 Box 395 PRETORIA 0001 from whom copies of reports in this series are available on request ISBN 0 7988 3254 1 Text, typeset by the National Research Institute... APPENDIX II: ORGANIC COMPOUNDS AND CUMULATIVE MATERIALSA5 APPENDIX III: EFFLUENT CHARACTERISTICS AND THEIR RELATIONSHIP TO WATER QUALITY CRITERIA A8 APPENDIX IV: ZONES OF MIXING All AD HOC WORKING COMMITTEE TITLES IN THIS SERIES In South Africa, man...

  4. Water at surfaces with tunable surface chemistries and the chiral imprint of water around DNA

    Science.gov (United States)

    Petersen, Poul

    Aqueous interfaces are ubiquitous in atmospheric chemistry and biological systems but are notoriously hard to probe experimentally. Surface-specific vibrational spectroscopy offers an avenue to directly probe the vibrational modes of the water OH stretching band but this method is challenging to implement to buried surfaces. Here we present results from sum-frequency generation (SFG) spectroscopy probing the buried interface between a functionalized surface and aqueous solutions. Studying such buried surfaces offers the advantage of being able to systematically tune the surface chemistry using self-assembled monolayers, i.e. the hydrophobic and hydrophilic character, and examine the effect on the interfacial water. In addition to water at these controlled surfaces, we have initiated studying water at biological surfaces. This includes the solvation structure around DNA. X-ray experiments at cryogenic temperatures have found crystallographic water in the minor grove of DNA giving rise to the notion of a spine of hydration surrounding DNA. Such structured water should exhibit a chiral structure adapted from DNA. We investigate if such a chiral water structure exist around DNA at room temperature using chiral SFG. This work was supported by the National Science Foundation under a NSF CAREER Grant (CHE-1151079).

  5. Invasive alien plants and water resources in South Africa: current understanding, predictive ability and research challenges

    CSIR Research Space (South Africa)

    Gorgens, AHM

    2004-01-01

    Full Text Available Predictions that invasive alien Plants would use significant amounts of water were a major factor in the establishment of South Africa's Working for Water programme, which aims to protect water resources by clearing these plants. The predictions...

  6. Towards norms and standards for water services in rural South Africa

    CSIR Research Space (South Africa)

    Duncker, Louiza C

    2015-07-01

    Full Text Available In South Africa, the current norms and standards for levels of water services have, over the last few decades, inadvertently focused on addressing water services in urban areas. The Minister responsible for water and sanitation initiated...

  7. Water resources in the Big Lost River Basin, south-central Idaho

    Science.gov (United States)

    Crosthwaite, E.G.; Thomas, C.A.; Dyer, K.L.

    1970-01-01

    The Big Lost River basin occupies about 1,400 square miles in south-central Idaho and drains to the Snake River Plain. The economy in the area is based on irrigation agriculture and stockraising. The basin is underlain by a diverse-assemblage of rocks which range, in age from Precambrian to Holocene. The assemblage is divided into five groups on the basis of their hydrologic characteristics. Carbonate rocks, noncarbonate rocks, cemented alluvial deposits, unconsolidated alluvial deposits, and basalt. The principal aquifer is unconsolidated alluvial fill that is several thousand feet thick in the main valley. The carbonate rocks are the major bedrock aquifer. They absorb a significant amount of precipitation and, in places, are very permeable as evidenced by large springs discharging from or near exposures of carbonate rocks. Only the alluvium, carbonate rock and locally the basalt yield significant amounts of water. A total of about 67,000 acres is irrigated with water diverted from the Big Lost River. The annual flow of the river is highly variable and water-supply deficiencies are common. About 1 out of every 2 years is considered a drought year. In the period 1955-68, about 175 irrigation wells were drilled to provide a supplemental water supply to land irrigated from the canal system and to irrigate an additional 8,500 acres of new land. Average. annual precipitation ranged from 8 inches on the valley floor to about 50 inches at some higher elevations during the base period 1944-68. The estimated water yield of the Big Lost River basin averaged 650 cfs (cubic feet per second) for the base period. Of this amount, 150 cfs was transpired by crops, 75 cfs left the basin as streamflow, and 425 cfs left as ground-water flow. A map of precipitation and estimated values of evapotranspiration were used to construct a water-yield map. A distinctive feature of the Big Lost River basin, is the large interchange of water from surface streams into the ground and from the

  8. ORNAMENTAL SPECIES USED IN WATER GARDENS FROM SOUTH KOREA

    Directory of Open Access Journals (Sweden)

    PARK SANG KUN

    2009-12-01

    Full Text Available Aquatic plants (hydrophytic plants or hydrophytes are plants that have adapted to live in or on aquatic environments. Because they are living under the water require numerous special adaptations, aquatic plants can only grow in water or permanently saturated soil. Aquatic vascular plants can be ferns or angiosperms (from a variety of families, including monocots and dicots. As opposed to plants types such as mesophytes and xerophytes, hydrophytes do not have a problem in retaining water due to the abundance of water in its environment. This means the plant has less need to regulate transpiration (indeed, the regulation of transpiration would require more energy than the possible benefits incurred.The Korean vascular flora contains 217 families, 1.045 genera, 3.034 species, and 406 infraspecific taxa [CHONG-WOOK PARK, 2007].In Mokp’o region (South Korea, in 1995, was identified hydrophytes species composed by 11 orders, 22 families, 23 genera, 38 species, 9 varieties, total 48 taxa. These were composed by 22 taxa emerged plants, 15 taxa floating-leaves plants, 8 taxa submerged plants and 3 taxa free-floating plants [JEONG WOO-GYU & al., 1995].The same research collective, in 1996, in Paksil, Yundang (South Korea swamp region was identified hydrophytes species composed by 11 orders, 22 families, 31 genera, 41 species, 10 varieties; it represents 12.1% of total plants. These is composed of 25 taxa emerged plants, 15 taxa floating-leaves plants, 9 taxa submerged plants and 3 taxa free-floating plants [JEONG WOO-GYU & al., 1996].This paper contains the classification of water plants and a brief description of some aquatic species used in Korean ancient and modern gardens in order to introduce in our country.

  9. Large-Scale Ichthyoplankton and Water Mass Distribution along the South Brazil Shelf

    Science.gov (United States)

    de Macedo-Soares, Luis Carlos Pinto; Garcia, Carlos Alberto Eiras; Freire, Andrea Santarosa; Muelbert, José Henrique

    2014-01-01

    Ichthyoplankton is an essential component of pelagic ecosystems, and environmental factors play an important role in determining its distribution. We have investigated simultaneous latitudinal and cross-shelf gradients in ichthyoplankton abundance to test the hypothesis that the large-scale distribution of fish larvae in the South Brazil Shelf is associated with water mass composition. Vertical plankton tows were collected between 21°27′ and 34°51′S at 107 stations, in austral late spring and early summer seasons. Samples were taken with a conical-cylindrical plankton net from the depth of chlorophyll maxima to the surface in deep stations, or from 10 m from the bottom to the surface in shallow waters. Salinity and temperature were obtained with a CTD/rosette system, which provided seawater for chlorophyll-a and nutrient concentrations. The influence of water mass on larval fish species was studied using Indicator Species Analysis, whereas environmental effects on the distribution of larval fish species were analyzed by Distance-based Redundancy Analysis. Larval fish species were associated with specific water masses: in the north, Sardinella brasiliensis was found in Shelf Water; whereas in the south, Engraulis anchoita inhabited the Plata Plume Water. At the slope, Tropical Water was characterized by the bristlemouth Cyclothone acclinidens. The concurrent analysis showed the importance of both cross-shelf and latitudinal gradients on the large-scale distribution of larval fish species. Our findings reveal that ichthyoplankton composition and large-scale spatial distribution are determined by water mass composition in both latitudinal and cross-shelf gradients. PMID:24614798

  10. A Water Rich Mars Surface Mission Scenario

    Science.gov (United States)

    Hoffman, Stephen J.; Andrews, Alida; Joosten, B. Kent; Watts, Kevin

    2017-01-01

    In an on-going effort to make human Mars missions more affordable and sustainable, NASA continues to investigate the innovative leveraging of technological advances in conjunction with the use of accessible Martian resources directly applicable to these missions. One of the resources with the broadest utility for human missions is water. Many past studies of human Mars missions assumed a complete lack of water derivable from local sources. However, recent advances in our understanding of the Martian environment provides growing evidence that Mars may be more "water rich" than previously suspected. This is based on data indicating that substantial quantities of water are mixed with surface regolith, bound in minerals located at or near the surface, and buried in large glacier-like forms. This paper describes an assessment of what could be done in a "water rich" human Mars mission scenario. A description of what is meant by "water rich" in this context is provided, including a quantification of the water that would be used by crews in this scenario. The different types of potential feedstock that could be used to generate these quantities of water are described, drawing on the most recently available assessments of data being returned from Mars. This paper specifically focuses on sources that appear to be buried quantities of water ice. (An assessment of other potential feedstock materials is documented in another paper.) Technologies and processes currently used in terrestrial Polar Regions are reviewed. One process with a long history of use on Earth and with potential application on Mars - the Rodriguez Well - is described and results of an analysis simulating the performance of such a well on Mars are presented. These results indicate that a Rodriguez Well capable of producing the quantities of water identified for a "water rich" human mission are within the capabilities assumed to be available on the Martian surface, as envisioned in other comparable Evolvable

  11. Streamers sliding on a water surface

    Science.gov (United States)

    Akishev, Yuri Semenov; Karalnik, Vladimir; Medvedev, Mikhail; Petryakov, Alexander; Trushkin, Nikolay; Shafikov, Airat

    2017-06-01

    The features of an electrical interaction between surface streamers (thin current filaments) sliding on a liquid and liquid itself are still unknown in many details. This paper presents the experimental results on properties of the surface streamers sliding on water with different conductivity (distilled and tap water). The streamers were initiated with a sharpened thin metallic needle placed above the liquid and stressed with a periodical or pulsed high voltage. Two electrode systems were used and tested. The first of them provides in advance the existence of the longitudinal electric field above the water. The second one imitates the electrode geometry of a pin-to-plane dielectric barrier discharge in which the barrier is a thick layer of liquid. The electrical and optical characteristics of streamers were complemented with data on the spectroscopic measurements. It was revealed that surface streamers on water have no spatial memory. Contribution to the topical issue "The 15th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XV)", edited by Nicolas Gherardi and Tomáš Hoder

  12. Uncertainty in surface water flood risk modelling

    Science.gov (United States)

    Butler, J. B.; Martin, D. N.; Roberts, E.; Domuah, R.

    2009-04-01

    Two thirds of the flooding that occurred in the UK during summer 2007 was as a result of surface water (otherwise known as ‘pluvial') rather than river or coastal flooding. In response, the Environment Agency and Interim Pitt Reviews have highlighted the need for surface water risk mapping and warning tools to identify, and prepare for, flooding induced by heavy rainfall events. This need is compounded by the likely increase in rainfall intensities due to climate change. The Association of British Insurers has called for the Environment Agency to commission nationwide flood risk maps showing the relative risk of flooding from all sources. At the wider European scale, the recently-published EC Directive on the assessment and management of flood risks will require Member States to evaluate, map and model flood risk from a variety of sources. As such, there is now a clear and immediate requirement for the development of techniques for assessing and managing surface water flood risk across large areas. This paper describes an approach for integrating rainfall, drainage network and high-resolution topographic data using Flowroute™, a high-resolution flood mapping and modelling platform, to produce deterministic surface water flood risk maps. Information is provided from UK case studies to enable assessment and validation of modelled results using historical flood information and insurance claims data. Flowroute was co-developed with flood scientists at Cambridge University specifically to simulate river dynamics and floodplain inundation in complex, congested urban areas in a highly computationally efficient manner. It utilises high-resolution topographic information to route flows around individual buildings so as to enable the prediction of flood depths, extents, durations and velocities. As such, the model forms an ideal platform for the development of surface water flood risk modelling and mapping capabilities. The 2-dimensional component of Flowroute employs

  13. Source Water Assessment for the Las Vegas Valley Surface Waters

    Science.gov (United States)

    Albuquerque, S. P.; Piechota, T. C.

    2003-12-01

    The 1996 amendment to the Safe Drinking Water Act of 1974 created the Source Water Assessment Program (SWAP) with an objective to evaluate potential sources of contamination to drinking water intakes. The development of a Source Water Assessment Plan for Las Vegas Valley surface water runoff into Lake Mead is important since it will guide future work on source water protection of the main source of water. The first step was the identification of the watershed boundary and source water protection area. Two protection zones were delineated. Zone A extends 500 ft around water bodies, and Zone B extends 3000 ft from the boundaries of Zone A. These Zones extend upstream to the limits of dry weather flows in the storm channels within the Las Vegas Valley. After the protection areas were identified, the potential sources of contamination in the protection area were inventoried. Field work was conducted to identify possible sources of contamination. A GIS coverage obtained from local data sources was used to identify the septic tank locations. Finally, the National Pollutant Discharge Elimination System (NPDES) Permits were obtained from the State of Nevada, and included in the inventory. After the inventory was completed, a level of risk was assigned to each potential contaminating activity (PCA). The contaminants of concern were grouped into five categories: volatile organic compounds (VOCs), synthetic organic compounds (SOCs), inorganic compounds (IOCs), microbiological, and radionuclides. The vulnerability of the water intake to each of the PCAs was assigned based on these five categories, and also on three other factors: the physical barrier effectiveness, the risk potential, and the time of travel. The vulnerability analysis shows that the PCAs with the highest vulnerability rating include septic systems, golf courses/parks, storm channels, gas stations, auto repair shops, construction, and the wastewater treatment plant discharges. Based on the current water quality

  14. Microfossils, carbonate lysocline and compensation depth in surface sediments of the northeastern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Chen Ronghua; Xu Jian; Meng Yi; Wang Dongjun; Liu Chuanlian; Huang Baoqi; Zhang Fuyuan

    2003-01-01

    Based on the quantitative analyses of abundance of planktonic foraminifera, benthic foraminifera, calcareous nannofossils, the ratios of calcareous to siliceous microfossils, and the determination of carbonate contents in the surface sediments of the northeastern South China Sea, it has been found that the carbonate contents, the abundance of planktonic foraminifera and calcareous nannoplankton, and the ratio of calcareous microfossils decrease rapidly while the ratio of the benthic foraminifera to the total foraminiferal fauna, specific value of siliceous microfossils, and the percentage of the agglutinated tests in the benthic foraminiferal fauna increase with the water depth. The results indicate that the microfossils abundance and ratio, and the carbonate content are closely related to the carbonate lysocline and carbonate compensation depth (CCD) in the study area. In addition, the carbonate lysocline and the CCD are different between the southern and northern parts of the South China Sea. Both the lysocline and the CCD are deeper in the south with 2 600 and 3 600 m than in the north with 2 200 and 3 400 m,respectively.

  15. Rapid Mapping of Surface Rupture from the South Napa Earthquake

    Science.gov (United States)

    Trexler, C. C.; Morelan, A. E., III; Oskin, M. E.

    2014-12-01

    Rapid documentation (3D data collection technique known as Structure from Motion (SfM), used in conjunction with traditional field reconnaissance, enabled us to rapidly locate and document surface ruptures from the Mw 6.0 South Napa earthquake. On the morning of the event, our field team used information available on social media to identify locations with potential surface rupture. Preliminary observations of surface rupture (measurements and geo-tagged photographs) were texted to the office-based team member who created digital maps of the rupture trace and shared them online via Twitter in near-real time. We documented many ephemeral features (such as offset roads, curbs, and driveways) along the rupture trace within 12 hours of the event, before these features were destroyed by road and infrastructure repair. We were able to return to most sites again within several days, allowing us to document continuing slip and create time-series datasets of offset features. After the collection and re-collection of data at selected sites, we made detailed measurements remotely using 3D models constructed with SfM. The ability to quantitatively project features into the fault plane using these models allows for accurate measurements of small features often difficult to observe and quantify in the field. Traditionally, even preliminary maps of rupture extent and offset magnitudes are not available for several days after an event because office-based processing and compilation is required. Because we were able to compile our data in real time, we distributed our results while they were still valuable for ongoing scientific response. Our work helped other science teams efficiently target fieldwork and instrument deployment; for example, one geodetic survey team used our surface rupture map to adjust their field deployment plans in an effort to capture rapidly-decaying postseismic movement. With social media and rapid, inexpensive data collection methods like SfM in mind

  16. Method for the prioritization of areas experiencing microbial pollution of surface water

    CSIR Research Space (South Africa)

    Venter, SN

    1998-01-01

    Full Text Available The increased threat of faecal pollution in recent years and the high priority of protecting human health by the government led to the initiation of a national microbial monitoring programme for surface water in South Africa. According to the design...

  17. Relation between Enterococcus concentrations and turbidity in fresh and saline recreational waters, coastal Horry County, South Carolina, 2003–04

    Science.gov (United States)

    Landmeyer, James E.; Garigen, Thomas J.

    2016-06-24

    Bacteria related to the intestinal tract of humans and other warm-blooded animals have been detected in fresh and saline surface waters used for recreational purposes in coastal areas of Horry County, South Carolina, since the early 2000s. Specifically, concentrations of the facultative anaerobic organism, Enterococcus, have been observed to exceed the single-sample regulatory limit of 104 colony forming units per 100 milliliters of water. Water bodies characterized by these concentrations are identified on the 303(d) list for impaired water in South Carolina; moreover, because current analytical methods used to monitor Enterococcus concentrations take up to 1 day for results to become available, water-quality advisories are not reflective of the actual health risk.

  18. Witwatersrand Water Ingress Project - Information Management System (WWIPIMS), South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Hild, S.; Sieste, M.; Barth, A.; Rudinskaya, J. [Beak Consultants GmbH, Freiberg (Germany); Croukamp, L.; Roos, M. [Council for Geoscience (CGS), Pretoria (South Africa)

    2006-07-01

    The Witwatersrand Water Ingress Project at the Council for Geoscience, South Africa (CGS) deals with an inventory, a risk assessment and the development of rehabilitation strategies for abandoned mining sites in the Witwatersrand Mining Basin. The main focus is the prevention of water ingress and to understand the future decanting scenario. An Information Management System consisting of both a relational database and an application for the Witwatersrand Water Ingress Project is established for accessing and managing all project-related data. This easy to use application makes the data available to all staff at the CGS via several modules as well as a GIS-component for accessing and querying spatial data. This will enable the scientists to derive further knowledge of the water flowing processes by directly using all of the existing up-to-date data. Many additional functions, such as the support for map printing on demand, extensive possibilities for inquiries, data import and export, diagrams and a GIS-viewer for spatial inquiries do complete the system. (orig.)

  19. The South Pacific Subtropical Mode Water in the Tasman Sea

    Institute of Scientific and Technical Information of China (English)

    HU Haibo; LIU Qinyu; LIN Xiaopei; LIU Wei

    2007-01-01

    From the synopical CTD sections in the WOCE PR11 repeated cruises, the South Pacific Subtropical Mode Water (SPSTMW) has been identified in the region of the Tasman Front Extension (TFE) around 29S to the east of Australia. In the depth range of 150-250 m, the SPSTMW appears as a thermostad with vertical temperature gradient lower than 1.6 ℃ (100 m)-1 and a tem perature range of 16.5-19.5 ℃ and as a pycnostad with PV lower than 2 × 10-10 m-1 s-1 and a potential density range of 25.4-26.0 kg m-3. Like the subtropical mode waters in the North Atlantic and North Pacific, the formation of the SPSTMW is associated with the convective mixing during the austral wintertime as manifested from the time series of the Argo floats. And cold water entrains into the mixed layer with the deepening mixed layer from September to the middle of October. During the wintertime formation process, mesoscale eddies prevailing in the TFE region play an important role in the SPSTMW formation, and have a great effect on the SPSTMW distribution in the next year. The deeper (shallower) mixed layer in wintertime, consistent with the depressed (uplifted) permanent thermocline, is formed by the anticyclonic (cyclonic) eddies, and the substantial mode water thicker than 50m is mainly found in the region of the anticyclonic eddies where the permanent thermocline is deeper than 450 m.

  20. Deep-water Oligocene pollen record from South China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Guoxuan; QIN Jungan; MAO Shaozhi

    2003-01-01

    Leg 184 of ODP recovered a record of deep- water sediments spanning the past 32.8 Ma from the South China Sea (SCS). The sediments of the Oligocene (32.8 - 23.8 Ma) at Site 1148 contain relatively abundant fossil pollen. The pollen analysis at Site 1148 has established the first pollen assemblage sequence of deep-water Oligocene in the China Sea. The pollen assemblages of the Oligocene are dominated by montane conifer tree pollen. The abundances of broad-leaved tree pollen are lower in the assemblages. Both of the montane conifer and broad-leaved tree pollen groups include mainly tropical-subtropical components. The pollen of cold and drought-enduring plants is present in lower content. The distinct change in pollen assemblage sequence of deep-water Oligocene of the SCS occurred at 32.0 Ma, indicative of an important shift of the Oligocene climate in the SCS region. The characteristics of the pollen flora of the deep-water Oligocene indicate the tropical montane rainforest and lowland rainforest developed on the areas around the SCS before 32.0 Ma, reflecting the warm and wet climatic condition. In the pollen flora of the Oligocene after 32.0 Ma, the temperate montane conifer and cool and drought-en- during deciduous tree taxa remarkably increased, indicating that the climate in the SCS region became comparatively cool and dry.

  1. How Water Advances on Superhydrophobic Surfaces

    Science.gov (United States)

    Schellenberger, Frank; Encinas, Noemí; Vollmer, Doris; Butt, Hans-Jürgen

    2016-03-01

    Superliquid repellency can be achieved by nano- and microstructuring surfaces in such a way that protrusions entrap air underneath the liquid. It is still not known how the three-phase contact line advances on such structured surfaces. In contrast to a smooth surface, where the contact line can advance continuously, on a superliquid-repellent surface, the contact line has to overcome an air gap between protrusions. Here, we apply laser scanning confocal microscopy to get the first microscopic videos of water drops advancing on a superhydrophobic array of micropillars. In contrast to common belief, the liquid surface gradually bends down until it touches the top face of the next micropillars. The apparent advancing contact angle is 180°. On the receding side, pinning to the top faces of the micropillars determines the apparent receding contact angle. Based on these observations, we propose that the apparent receding contact angle should be used for characterizing superliquid-repellent surfaces rather than the apparent advancing contact angle and hysteresis.

  2. Grey mullet (Mugilidae) as possible indicators of global warming in South African estuaries and coastal waters.

    Science.gov (United States)

    James, Nicola C; Whitfield, Alan K; Harrison, Trevor D

    2016-12-01

    The grey mullet usually occur in large numbers and biomass in the estuaries of all three South African biogeographic regions, thus making it an ideal family to use in terms of possibly acting as an environmental indicator of global warming. In this analysis the relative estuarine abundance of the dominant three groups of mugilids, namely tropical, warm-water and cool-water endemics, were related to sea surface coastal temperatures. The study suggests a strong link between temperature and the distribution and abundance of the three mullet groups within estuaries and indicates the potential of this family to act as an indicator for future climate change within these systems and adjacent coastal waters.

  3. Convergent surface water distributions in U.S. cities

    Science.gov (United States)

    M.K. Steele; J.B. Heffernan; N. Bettez; J. Cavender-Bares; P.M. Groffman; J.M. Grove; S. Hall; S.E. Hobbie; K. Larson; J.L. Morse; C. Neill; K.C. Nelson; J. O' Neil-Dunne; L. Ogden; D.E. Pataki; C. Polsky; R. Roy Chowdhury

    2014-01-01

    Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However, the scope and consequences of surface water redistribution at broad spatial scales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and...

  4. Climate change impacts on water yields and demands in south-western Australia

    Science.gov (United States)

    McFarlane, Don; Stone, Roy; Martens, Sasha; Thomas, Jonathan; Silberstein, Richard; Ali, Riasat; Hodgson, Geoff

    2012-12-01

    SummaryA climate shift in the mid 1970s reduced rainfalls in south-western Australia by 10-15% and inflows into reservoirs that supply the city of Perth (population 1.8 m) by more than half. The region has a Mediterranean climate, similar to other areas in the world experiencing reductions in rainfall and rises in temperatures. Rainfall-runoff modelling has indicated that streamflows may reduce by a further quarter by 2030 or by half if a dry future climate is experienced. Groundwater levels on the coastal plain in south-western Australia have fallen since the mid 1970s where unconfined aquifers are covered with perennial vegetation, including under the main water supply aquifer for Perth. Modelled projections are that groundwater levels in most areas will continue to fall through to 2030 under most future climate scenarios. Projected streamflows and groundwater levels indicate reduced water availability but these need to be converted to projected water yields, i.e. the amount of water that can be diverted for consumptive use. This paper reports how projections of future streamflow and groundwater levels were used to estimate 2030 divertible water yields for a 62,500 km2 area in south-western Australia. These yields were then compared with estimates of water demands in 2030 to identify areas of water surplus and deficit under clearly defined assumptions. The methods used to define future yields are based on sets of rules that could be varied by water managers if desired. Surface water yields are estimated to decrease by about 24% (possible range of -4% to -49%) which is similar to the projected reduction in runoff (-25% with a range of -7% to -42%). Groundwater yields are projected to fall by only about 2% (range of +2% to -7%) because of reductions in evapotranspiration and drainage losses as watertables fall where groundwater levels are close to the surface. In addition, recharge remains relatively high under cleared areas used for non-irrigated agriculture. In

  5. Water footprint assessment along the wheat-bread value chain towards the sustainable use of freshwater in South Africa

    Science.gov (United States)

    Mohlotsane, Pascalina; Owusu-Sekyere, Enoch; Jordaan, Henry

    2017-04-01

    A significant amount of water is used in food production. The current increase in demand for food and impact of climate change place much pressure on the available water resources. South Africa is soon approaching complete utilisation of its available surface water, with irrigated agriculture accountable for about 63% of the country's available water use. This poses a threat to food security. Wheat is the largest winter cereal crop produced in South Africa, approximately 80% of this wheat is used to produce Bread. Bread consumption in South Africa is estimated at 2.8 billion loaves per annum. About 62 loaves of bread are consumed per person per annum with noticeable differences in preferences. Therefore, it is important to account for the amount of water used along the wheat-bread production chain. In this paper, we examined water footprint along the wheat-bread value chain. The water footprint concept provides an appropriate framework for analysis to find the link between the consumption of agricultural goods and the use of water resources. The paper employed the Global Water Footprint Standard approach to calculating the volumetric green, blue and grey water footprint along the wheat-bread value chain. Our findings reveal that wheat production at the farm level accounts for 99.95 percent of the total water footprint of the bread, while processing and wholesale levels only account for 0.56 per cent. Our findings highlight the importance of effective and efficient water use at the farm level for wheat production. Specifically, the total water footprint of wheat bread is 937.42m3.ton-1. The green water component was found to be 190.59m3.ton-1 and that of blue water was 745.28 m3.ton-1. Grey water footprint accounted for only 1.55 m3.ton-1. The results indicate that the amount of water used at farm level is the largest contributor to the total water footprint of bread. Given the blue water scarcity situation in South Africa, it is very critical for wheat producers to

  6. Harmful Algal in Banyuasin Coastal Waters, South Sumatera

    Directory of Open Access Journals (Sweden)

    Riris Aryawati

    2016-09-01

    Full Text Available Phytoplankton have important as food-chain major component and primary production of marine environment. However, high abundance of phytoplankton could give harmful effects toward water ecosystem. Moreover, they could produce toxic substances that will be accumulated within their consumer. This accumulation could be dangerous for human or animals.This research were aimed to determine and calculatespecies of harmful algae in Banyuasin coastal waters. The study was conducted on April, June, August, October and December of 2013, and in February 2014, at ten stations. Phytoplankton samples were taken vertically using plankton nets. In the form of cone-shaped with a diameter of 30 cm, length 100 cm and mesh size 30 μm.The result showed that there are 35 genera of phytoplankton. That have been found and consisted of four groups; Bacillariophyceae, Dinophyceae, Cyanophyceae and Chlorophyceae. 13 species were identified as Harmful Algal (Chaetoceros, Coscinodiscus, Nitzschia, Skeletonema, Thalassiosira, Alexandrium, Ceratium, Dinophysis, Noctiluca, Protoperidinium, Prorocentrum, Anabaena dan Oscillatoria, with seven of them were known for having toxin (Nitzschia, Alexandrium, Dinophysis, Protoperidinium Prorocentrum, Anabaena and Oscillatoria. Monitoring result showed that the highest number of species of potential harmful algal blooms (HABs occured in June and the highest abundance occured in August, especially Chaetoceros and Skeletonema.How to CiteAryawati, R., Bengen, D. G., Prartono, T., & Zulkifli, H. (2016. Harmful Algal in Banyuasin Coastal Waters, South Sumatera. Biosaintifika: Journal of Biology & Biology Education, 8(2, 231-239.

  7. Bacteriophages as surface and ground water tracers

    Directory of Open Access Journals (Sweden)

    P. Rossi

    1998-01-01

    Full Text Available Bacteriophages are increasingly used as tracers for quantitative analysis in both hydrology and hydrogeology. The biological particles are neither toxic nor pathogenic for other living organisms as they penetrate only a specific bacterial host. They have many advantages over classical fluorescent tracers and offer the additional possibility of multi-point injection for tracer tests. Several years of research make them suitable for quantitative transport analysis and flow boundary delineation in both surface and ground waters, including karst, fractured and porous media aquifers. This article presents the effective application of bacteriophages based on their use in differing Swiss hydrological environments and compares their behaviour to conventional coloured dye or salt-type tracers. In surface water and karst aquifers, bacteriophages travel at about the same speed as the typically referenced fluorescent tracers (uranine, sulphurhodamine G extra. In aquifers of interstitial porosity, however, they appear to migrate more rapidly than fluorescent tracers, albeit with a significant reduction in their numbers within the porous media. This faster travel time implies that a modified rationale is needed for defining some ground water protection area boundaries. Further developments of other bacteriophages and their documentation as tracer methods should result in an accurate and efficient tracer tool that will be a proven alternative to conventional fluorescent dyes.

  8. Bacteriophages as surface and ground water tracers

    Science.gov (United States)

    Rossi, P.; Dörfliger, N.; Kennedy, K.; Müller, I.; Aragno, M.

    Bacteriophages are increasingly used as tracers for quantitative analysis in both hydrology and hydrogeology. The biological particles are neither toxic nor pathogenic for other living organisms as they penetrate only a specific bacterial host. They have many advantages over classical fluorescent tracers and offer the additional possibility of multi-point injection for tracer tests. Several years of research make them suitable for quantitative transport analysis and flow boundary delineation in both surface and ground waters, including karst, fractured and porous media aquifers. This article presents the effective application of bacteriophages based on their use in differing Swiss hydrological environments and compares their behaviour to conventional coloured dye or salt-type tracers. In surface water and karst aquifers, bacteriophages travel at about the same speed as the typically referenced fluorescent tracers (uranine, sulphurhodamine G extra). In aquifers of interstitial porosity, however, they appear to migrate more rapidly than fluorescent tracers, albeit with a significant reduction in their numbers within the porous media. This faster travel time implies that a modified rationale is needed for defining some ground water protection area boundaries. Further developments of other bacteriophages and their documentation as tracer methods should result in an accurate and efficient tracer tool that will be a proven alternative to conventional fluorescent dyes.

  9. Water droplet evaporation from sticky superhydrophobic surfaces

    Science.gov (United States)

    Lee, Moonchan; Kim, Wuseok; Lee, Sanghee; Baek, Seunghyeon; Yong, Kijung; Jeon, Sangmin

    2017-07-01

    The evaporation dynamics of water from sticky superhydrophobic surfaces was investigated using a quartz crystal microresonator and an optical microscope. Anodic aluminum oxide (AAO) layers with different pore sizes were directly fabricated onto quartz crystal substrates and hydrophobized via chemical modification. The resulting AAO layers exhibited hydrophobic or superhydrophobic characteristics with strong adhesion to water due to the presence of sealed air pockets inside the nanopores. After placing a water droplet on the AAO membranes, variations in the resonance frequency and Q-factor were measured throughout the evaporation process, which were related to changes in mass and viscous damping, respectively. It was found that droplet evaporation from a sticky superhydrophobic surface followed a constant contact radius (CCR) mode in the early stage of evaporation and a combination of CCR and constant contact angle modes without a Cassie-Wenzel transition in the final stage. Furthermore, AAO membranes with larger pore sizes exhibited longer evaporation times, which were attributed to evaporative cooling at the droplet interface.

  10. Impact of land surface processes on the South American warm season climate

    Energy Technology Data Exchange (ETDEWEB)

    Ma, H.-Y.; Mechoso, C.R.; Xiao, H.; Wu, C.-M. [University of California Los Angeles, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA (United States); Xue, Y. [University of California Los Angeles, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA (United States); University of California Los Angeles, Department of Geography, Los Angeles, CA (United States); Li, J.-L. [California Institute of Technology, Jet Propulsion Laboratory, Pasadena, CA (United States); Sales, F.De [University of California Los Angeles, Department of Geography, Los Angeles, CA (United States)

    2011-07-15

    The present study demonstrates that (1) the simulation of the South American warm season (December-February) climate by an atmospheric general circulation model (AGCM) is sensitive to the representation of land surface processes, (2) the sensitivity is not confined to the ''hot spot'' in Amazonia, and (3) upgrading the representation of those processes can produce a significant improvement in AGCM performance. The reasons for sensitivity and higher success are investigated based on comparisons between observational datasets and simulations by the AGCM coupled to either a simple land scheme that specifies soil moisture availability or to the Simplified Simple Biosphere Model (SSiB) that allows for consideration of soil and vegetation biophysical process. The context for the study is the UCLA AGCM. The most notable simulation improvements are along the lee of the Andes in the lower troposphere, where poleward flow transports abundant moisture from the Amazon basin to high latitudes, and in the monsoon region where the intensity and pattern of precipitation and upper level ice water content are more realistic. It is argued that a better depiction of the Chaco Low, which is controlled by local effects of land surface processes, decisively contributes to the superior model performance with low-level flows in central South America. The better representation of the atmospheric column static stability and large-scale moisture convergence in tropical South America contribute to more realistic precipitation over the monsoon region. The overall simulation improvement is, therefore, due to a combination of different regional processes. This finding is supported by idealized AGCM experiments. (orig.)

  11. Long-term changes of South China Sea surface temperatures in winter and summer

    Science.gov (United States)

    Park, Young-Gyu; Choi, Ara

    2017-07-01

    Utilizing available atmospheric and oceanographic reanalysis data sets, the long-term trend in South China Sea (SCS) sea surface temperature (SST) between 1950 and 2008 and the governing processes are investigated. Both winter and summer SST increased by comparable amounts, but the warming patterns and the governing processes were different. Strong warming in winter occurred in a deep central area, and during summer in the southern region. In winter the net heat flux into the sea increased, contributing to the warming. The spatial pattern of the heat flux, however, was different from that of the warming. Heat flux increased over the coastal area where warming was weaker, but decreased over the deeper area where warming was stronger. The northeasterly monsoon wind weakened lowering the shoreward Ekman transport and the sea surface height gradient. The cyclonic gyre which transports cold northern water to the south weakened, thereby warming the ocean. The effect was manifested more strongly along the southward western boundary current inducing warming in the deep central part. In summer however, the net surface heat flux decreased and could not contribute to the warming. Over the southern part of the SCS, the weakening of the southwesterly summer monsoon reduced southeastward Ekman transport, which is parallel to the mean SST gradient. Southeastward cold advection due to Ekman transport was reduced, thereby warming the surface near the southeastern boundary of the SCS. Upwelling southeast of Vietnam was also weakened, raising the SST east of Vietnam contributing to the southern summer warming secondarily. The weakening of the winds in each season was the ultimate cause of the warming, but the responses of the ocean that lead to the warming were different in winter and summer.

  12. Eutrophication and cyanobacteria in South Africa’s standing water bodies: A view from space

    CSIR Research Space (South Africa)

    Matthews, MW

    2015-05-01

    Full Text Available Satellite remote sensing can make a significant contribution to monitoring water quality in South African standing water bodies. Eutrophication, defined as enrichment by nutrients, and toxin-producing cyanobacteria (blue-green algae) blooms pose a...

  13. Economic burden of diarrhoea in the Olifants Water Management Area, South Africa

    CSIR Research Space (South Africa)

    Steyn, M

    2011-07-01

    Full Text Available This presentation highlights the economic burden of diarrhoea in the Olifants Water Management Area, South Africa. It concludes that water pollution prevention is cheaper than diarrhoea treatment....

  14. South Africa and the Human Right to Water: Equity, Ecology and the Public Trust Doctrine

    National Research Council Canada - National Science Library

    David Takacs

    2016-01-01

    ...: "Everyone has the right to have access to sufficient food and water." In this paper, I analyze South Africa's revolutionary legal vision for marrying social equity to ecology in fulfilling the right to water...

  15. Ecosystem services, efficiency, sustainability and equity: South Africa's Working for Water Programme

    CSIR Research Space (South Africa)

    Van Wilgen, BW

    1998-09-01

    Full Text Available In this paper, South Africa’s working for water programme is described. The programme maximizes an ecosystem services (the delivery of water), enhances sustainability by eliminating invading alien plants, and promotes social equity through jobs...

  16. Trends of Productivity of Water in Rainfed Crops in Ilorin South ...

    African Journals Online (AJOL)

    Trends of Productivity of Water in Rainfed Crops in Ilorin South, Kwara State, ... on the aspect of increase productivity of water, formulate and adopt appropriate ... in the region include poor soil nutrient and lack of proper crop management.

  17. Do low-cost ceramic water filters improve water security in rural South Africa?

    OpenAIRE

    Lange, Jens; Materne, Tineke; Grüner, Jörg

    2016-01-01

    This study examines the performance of a low-cost ceramic candle filter system (CCFS) for point of use (POU) drinking water treatment in the village of Hobeni, Eastern Cape Province, South Africa. A stepwise laboratory test documented the negative effects of repeated loading and ambient field temperatures. Moreover, CCFS were distributed in Hobeni and a survey was carried out among their users. The performance of 51 CCFS was evaluated by dip slides and related to human factors. Already after ...

  18. 75 FR 69436 - Public Water System Supervision Program Revision for the State of South Dakota

    Science.gov (United States)

    2010-11-12

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY Public Water System Supervision Program Revision for the State of South Dakota AGENCY... hereby given that the State of South Dakota has revised its Public Water System Supervision...

  19. Nitrate reducing activity pervades surface waters during upwelling.

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, S.O.; Halarnekar, R.; Malik, A.; Vijayan, V.; Varik, S.; RituKumari; Jineesh V.K.; Gauns, M.U.; Nair, S.; LokaBharathi, P.A.

    Nitrate reducing activity (NRA) is known to be mediated by microaerophilic to anaerobic bacteria and generally occurs in the sub-surface waters. However, we hypothesize that NRA could become prominent in the surface waters during upwelling. Hence...

  20. Analysis of the impact of water level fluctuations on macrophytes in Miyun Reservoir after receiving water transferred by the South-to-North Water Diversion Project

    Science.gov (United States)

    Yu, L.; Gu, H.; Lou, C. H.; Zhang, L.; Meng, Q. Y.

    2016-08-01

    As the main primary producers in aquatic ecosystems, macrophytes affect the structure and function of aquatic ecosystems, and their distribution is controlled by water depth. Miyun Reservoir in Beijing will have to experience substantial changes in water level and surface area as it begins to receive water transferred by the South-to-North Water Diversion Project, which will have an adverse impact on the macrophytes growing there. In this study, a hydrodynamic model was constructed with MIKE21 and then used in a simulation in three scenarios: dry year, normal year and wet year. The results suggest that during water diversion, the annual and interannual water level fluctuations will be too significant for them to adapt and as a result, the original macrophytes in the reservoir tend to die and disappear completely. The area of the zone suitable for macrophyte growth, or suitable growth zone (SGZ), fluctuated. Restricted by the main dam and auxiliary dam to its south, the overall suitable growth zone moved toward the northeast and northwest of the reservoir, with a northeastward movement of its centroid. The distance and path of movement varied between scenarios. After the water diversion was completed, the suitable growth zone shrunk in the three scenarios. It is predicted that the macrophyte species diversity and richness of the reservoir can recover to the levels recorded before water diversion only in dry year. These results suggest that manual interventions should be implemented after water diversion to speed up the natural recovery of aquatic plant communities in Miyun Reservoir and thereby maintain the stability of the aquatic ecosystem.

  1. Wettability and water uptake of holm oak leaf surfaces

    OpenAIRE

    2014-01-01

    Plant trichomes play important protective functions and may have a major influence on leaf surface wettability. With the aim of gaining insight into trichome structure, composition and function in relation to water-plant surface interactions, we analyzed the adaxial and abaxial leaf surface of Quercus ilex L. (holm oak) as model. By measuring the leaf water potential 24 h after the deposition of water drops on to abaxial and adaxial surfaces, evidence for water penetration through the upper l...

  2. Interocean exchanges and spreading of the Antarctic Intermediate Water south of Africa

    Science.gov (United States)

    Rusciano, Dr; Speich, Dr; Arhan, Dr; Blanke, Dr; Ollitrault, Dr

    2012-04-01

    Argo hydrographic profiles from different projects collected between 2004-2008 in the South Atlantic south of Africa in combination with hydrographic transects are used to describe the characteristic and the flow of the Antarctic Intermediate Water (AAIW). The study area was divided in 9 subregions on the base of the front patterns that have shown to be relevant to the AAIW dynamics, the Subtropical Front (STF) and the Subantarctic Front (SAF). The fronts mean position have been computed from Argo floats as function of the calculated surface dynamic height. We present here estimates of the relative importance of the different regional varieties of AAIW (south-west Atlantic, characterized by S≤34.2, Indian, with S≥34.3, and a new intermediate water found north of the SSTF between 10°W and 12°E and south of the SSTF between 12°E and 40°E with 34.2ANDRO velocity dataset (Ollitrault and Rannou, 2011) we estimates for the regional AAIW absolute geostrophic velocity and transport within the isoneutral layer. The AAIW moves with speeds between 0.1 - 0.3 m/s in the Agulhas Current and 0.1 - 0.23 m/s in the Agulhas Return Current. AAIW flows in the subtropical region have approximately 0.03 m/s speed. A net increase of the eastward transport is evident from 40°S to 60°S, in particular at the SSTF and SAF location. The AAIW cross frontal transport shows an evident variability between the three front lines, with a maximum northward transport of 15 about Sv across the SAF between 12°E and 23°E.

  3. Groundwater–surface water interactions in wetlands for integrated water resources management (preface)

    NARCIS (Netherlands)

    Schot, P.P.; Winter, T.C.

    2006-01-01

    Groundwater–surface water interactions constitute an important link between wetlands and the surrounding catchment. Wetlands may develop in topographic lows where groundwater exfiltrates. This water has its functions for ecological processes within the wetland, while surface water outflow from

  4. General survey and conclusions with regard to the connection of water quantity and water quality studies of surface waters

    NARCIS (Netherlands)

    Rijtema, P.E.

    1979-01-01

    Publikatie die bestaat uit twee delen: 1. General survey of the relation between water quantity and water quality; 2. Conclusions with regard to the connection of water quantity and water quality studies of surface waters

  5. Preozonation of bromide-bearing source water in south China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effectiveness of preozonation was evaluated on treating a bromide-bearing dam source water in south China through batch-scale experiments. Preozonation at ozone doses of 0.5-1.0 mg/L (at ozone consumption base) enhanced total organic carbon(TOC) removal through coagulation, and resulted in an almost linear reduction of ultraviolet absorbance at 254 nm (UV254). The removals of TOC (after coagulation) and UV254 at the ozone dose of 1.0 mg/L were 36% and 70%, respectively. Preozonation at an ozone dose between 0.5 and 1.0 mg/L resulted in the removal of disinfection byproducts formation potential (DBFP) including trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP) for about 50%. The removals of THMFP and HAAFP decreased with the further increase of ozone dose. Ozonation of bromide-bearing water (bromide concentration,34 μg/L) produced a bromate concentration under the detection limit(2 μg/L) at ozone doses < 1.5 mg/L. However, bromate >10 μg/L could be produced when the bromide concentration was increased to 96 μg/L.

  6. Impact of Water Withdrawals from Groundwater and Surface Water on Continental Water Storage Variations

    Science.gov (United States)

    Doell, Petra; Hoffmann-Dobrev, Heike; Portmann, Felix T.; Siebert, Stefan; Eicker, Annette; Rodell, Matthew; Strassberg, Gil

    2011-01-01

    Humans have strongly impacted the global water cycle, not only water flows but also water storage. We have performed a first global-scale analysis of the impact of water withdrawals on water storage variations, using the global water resources and use model WaterGAP. This required estimation of fractions of total water withdrawals from groundwater, considering five water use sectors. According to our assessment, the source of 35% of the water withdrawn worldwide (4300 cubic km/yr during 1998-2002) is groundwater. Groundwater contributes 42%, 36% and 27% of water used for irrigation, households and manufacturing, respectively, while we assume that only surface water is used for livestock and for cooling of thermal power plants. Consumptive water use was 1400 cubic km/yr during 1998-2002. It is the sum of the net abstraction of 250 cubic km/yr of groundwater (taking into account evapotranspiration and return flows of withdrawn surface water and groundwater) and the net abstraction of 1150 km3/yr of surface water. Computed net abstractions indicate, for the first time at the global scale, where and when human water withdrawals decrease or increase groundwater or surface water storage. In regions with extensive surface water irrigation, such as Southern China, net abstractions from groundwater are negative, i.e. groundwater is recharged by irrigation. The opposite is true for areas dominated by groundwater irrigation, such as in the High Plains aquifer of the central USA, where net abstraction of surface water is negative because return flow of withdrawn groundwater recharges the surface water compartments. In intensively irrigated areas, the amplitude of seasonal total water storage variations is generally increased due to human water use; however, in some areas, it is decreased. For the High Plains aquifer and the whole Mississippi basin, modeled groundwater and total water storage variations were compared with estimates of groundwater storage variations based on

  7. Comparison among four kinds of data of sea surface wind stress in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    谢强; 王卫强; 毛庆文

    2002-01-01

    By using remote sensing (ERS) data, FSU data, GOADS data and Hellerman & Rcsenstein objective analysis data to analyze the sea surface wind stress in the South China Sea, it is found that the remote sensing data have higher resolution and more reasonable values. Therefore we suggest that remote sensing data be chosen in the study of climatological features of sea surface wind stress and its seasonal variability in the South China Sea, especially in the study of small and middle scale eddies.

  8. Salinity maxima associated with some sub-surface water masses in the upper layers of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Varadachari, V.V.R.; Murty, C.S.; Reddy, C.V.G.

    The distribution of some sub-surface water masses in the western bay of Bengal during the south-west monsoon period is presented. Based on the salinity maxima and sigma t values the existence of waters of Persian Gulf and Red Sea origin could...

  9. Recovery from acidification in European surface waters

    Directory of Open Access Journals (Sweden)

    C. D. Evans

    2001-01-01

    Full Text Available Water quality data for 56 long-term monitoring sites in eight European countries are used to assess freshwater responses to reductions in acid deposition at a large spatial scale. In a consistent analysis of trends from 1980 onwards, the majority of surface waters (38 of 56 showed significant (p ≤0.05 decreasing trends in pollution-derived sulphate. Only two sites showed a significant increase. Nitrate, on the other hand, had a much weaker and more varied pattern, with no significant trend at 35 of 56 sites, decreases at some sites in Scandinavia and Central Europe, and increases at some sites in Italy and the UK. The general reduction in surface water acid anion concentrations has led to increases in acid neutralising capacity (significant at 27 of 56 sites but has also been offset in part by decreases in base cations, particularly calcium (significant at 26 of 56 sites, indicating that much of the improvement in runoff quality to date has been the result of decreasing ionic strength. Increases in acid neutralising capacity have been accompanied by increases in pH and decreases in aluminium, although fewer trends were significant (pH 19 of 56, aluminium 13 of 53. Increases in pH appear to have been limited in some areas by rising concentrations of organic acids. Within a general trend towards recovery, some inter-regional variation is evident, with recovery strongest in the Czech Republic and Slovakia, moderate in Scandinavia and the United Kingdom, and apparently weakest in Germany. Keywords: acidification, recovery, European trends, sulphate, nitrate, acid neutralising capacity

  10. Assessing the Blue and Green Water Footprint of Lucerne for Milk Production in South Africa

    OpenAIRE

    Morne E. Scheepers; Henry Jordaan

    2016-01-01

    The Global Water Footprint Standard approach was used to calculate the volumetric blue and green water footprint indicator for lucerne production as important feed for dairy cows in a major lucerne production region in South Africa. The degree of sustainability of water use then was assessed by comparing water use to water availability for the region. The results show a volumetric water footprint indicator of 378 m3/tonne of lucerne. Of the total blue and green water footprint, 55% is green w...

  11. Integration challenges of water and land reform – A critical review of South Africa [chapter

    CSIR Research Space (South Africa)

    Funke, Nicola S

    2011-12-01

    Full Text Available , and to manage South Africa?s situation of water scarcity (Funke et al., 2007b). In combination, South Africa?s Water Services Act of 1997 and National Water Act of 1998 were designed to ?redress the inequalities of racial and gender discrimination of the past... goal of redressing past racial and gender inequality means that South Africa?s water reform is expected to deliver on changes in process (holistic, decentralised, participatory and economically cost effective), social outcomes (Woodhouse, 2008...

  12. The influence of South-North Water Diversion Middle-Line Project on agricultural water in Jingmen and countermeasures

    Science.gov (United States)

    Jiang, Li

    2017-08-01

    Based on the investigation, the author puts forward a variety of adverse impacts of South-North Water Diversion Middle-Line Project on agricultural water in Jingmen. For examples, the land resource utilization is reduced; the farmland irrigation water cannot be guaranteed; the pollution of agricultural water is very serious. Combining the characteristics of South - North Water Diversion Project with the agricultural development in Jingmen, some countermeasures are provided in this paper, such as enhancing soil-water protection relying on related laws and policies, developing water resources and optimizing the use of water sources, adjusting the planting structure by adopting water-saving irrigation projects, developing dry farming and water-saving agriculture, controlling water pollution, and so on.

  13. Structured free-water clusters near lubricating surfaces are essential in water-based lubrication.

    Science.gov (United States)

    Hou, Jiapeng; Veeregowda, Deepak H; de Vries, Joop; Van der Mei, Henny C; Busscher, Henk J

    2016-10-01

    Water-based lubrication provides cheap and environmentally friendly lubrication and, although hydrophilic surfaces are preferred in water-based lubrication, often lubricating surfaces do not retain water molecules during shear. We show here that hydrophilic (42° water contact angle) quartz surfaces facilitate water-based lubrication to the same extent as more hydrophobic Si crystal surfaces (61°), while lubrication by hydrophilic Ge crystal surfaces (44°) is best. Thus surface hydrophilicity is not sufficient for water-based lubrication. Surface-thermodynamic analyses demonstrated that all surfaces, regardless of their water-based lubrication, were predominantly electron donating, implying water binding with their hydrogen groups. X-ray photoelectron spectroscopy showed that Ge crystal surfaces providing optimal lubrication consisted of a mixture of -O and =O functionalities, while Si crystal and quartz surfaces solely possessed -O functionalities. Comparison of infrared absorption bands of the crystals in water indicated fewer bound-water layers on hydrophilic Ge than on hydrophobic Si crystal surfaces, while absorption bands for free water on the Ge crystal surface indicated a much more pronounced presence of structured, free-water clusters near the Ge crystal than near Si crystal surfaces. Accordingly, we conclude that the presence of structured, free-water clusters is essential for water-based lubrication. The prevalence of structured water clusters can be regulated by adjusting the ratio between surface electron-donating and electron-accepting groups and between -O and =O functionalities.

  14. Potentially hazardous substances in surface waters. II. Cholinesterase inhibitors in Dutch surface waters

    NARCIS (Netherlands)

    Greve, P.A.; Freudenthal, J.; Wit, S.L.

    1972-01-01

    Several analytical methods were employed to determine the concentrations of cholinesterase inhibitors in several Dutch surface waters. An Auto-Analyzer method was used for screening purposes; thin-layer chromatography and gas-liquid chromatography-mass spectrometry were used for identification and q

  15. Do low-cost ceramic water filters improve water security in rural South Africa?

    Science.gov (United States)

    Lange, Jens; Materne, Tineke; Grüner, Jörg

    2016-10-01

    This study examined the performance of a low-cost ceramic candle filter system (CCFS) for point of use (POU) drinking water treatment in the village of Hobeni, Eastern Cape Province, South Africa. CCFSs were distributed in Hobeni and a survey was carried out among their users. The performance of 51 CCFSs was evaluated by dip slides and related to human factors. Already after two-thirds of their specified lifetime, none of the distributed CCFSs produced water without distinct contamination, and more than one-third even deteriorated in hygienic water quality. Besides the water source (springs were preferable compared to river or rain water), a high water throughput was the dominant reason for poor CCFS performance. A stepwise laboratory test documented the negative effects of repeated loading and ambient field temperatures. These findings suggest that not every CCFS type per se guarantees improved drinking water security and that the efficiency of low-cost systems should continuously be monitored. For this purpose, dip slides were found to be a cost-efficient alternative to standard laboratory tests. They consistently underestimated microbial counts but can be used by laypersons and hence by the users themselves to assess critical contamination of their filter systems.

  16. Beyond water, beyond boundaries: spaces of water management in the Krishna river basin, South India.

    Science.gov (United States)

    Venot, Jean-Philippe; Bharati, Luna; Giordano, Mark; Molle, François

    2011-01-01

    As demand and competition for water resources increase, the river basin has become the primary unit for water management and planning. While appealing in principle, practical implementation of river basin management and allocation has often been problematic. This paper examines the case of the Krishna basin in South India. It highlights that conflicts over basin water are embedded in a broad reality of planning and development where multiple scales of decisionmaking and non-water issues are at play. While this defines the river basin as a disputed "space of dependence", the river basin has yet to acquire a social reality. It is not yet a "space of engagement" in and for which multiple actors take actions. This explains the endurance of an interstate dispute over the sharing of the Krishna waters and sets limits to what can be achieved through further basin water allocation and adjudication mechanisms – tribunals – that are too narrowly defined. There is a need to extend the domain of negotiation from that of a single river basin to multiple scales and to non-water sectors. Institutional arrangements for basin management need to internalise the political spaces of the Indian polity: the states and the panchayats. This re-scaling process is more likely to shape the river basin as a space of engagement in which partial agreements can be iteratively renegotiated, and constitute a promising alternative to the current interstate stalemate.

  17. Ground Water Atlas of the United States: Segment 8, Montana, North Dakota, South Dakota, Wyoming

    Science.gov (United States)

    Whitehead, R.L.

    1996-01-01

    The States of Montana, North Dakota, South Dakota, and Wyoming compose the 392,764-square-mile area of Segment 8, which is in the north-central part of the continental United States. The area varies topographically from the high rugged mountain ranges of the Rocky Mountains in western Montana and Wyoming to the gently undulating surface of the Central Lowland in eastern North Dakota and South Dakota (fig. 1). The Black Hills in southwestern South Dakota and northeastern Wyoming interrupt the uniformity of the intervening Great Plains. Segment 8 spans the Continental Divide, which is the drainage divide that separates streams that generally flow westward from those that generally flow eastward. The area of Segment 8 is drained by the following major rivers or river systems: the Green River drains southward to join the Colorado River, which ultimately discharges to the Gulf of California; the Clark Fork and the Kootenai Rivers drain generally westward by way of the Columbia River to discharge to the Pacific Ocean; the Missouri River system and the North Platte River drain eastward and southeastward to the Mississippi River, which discharges to the Gulf of Mexico; and the Red River of the North and the Souris River drain northward through Lake Winnipeg to ultimately discharge to Hudson Bay in Canada. These rivers and their tributaries are an important source of water for public-supply, domestic and commercial, agricultural, and industrial uses. Much of the surface water has long been appropriated for agricultural use, primarily irrigation, and for compliance with downstream water pacts. Reservoirs store some of the surface water for flood control, irrigation, power generation, and recreational purposes. Surface water is not always available when and where it is needed, and ground water is the only other source of supply. Ground water is obtained primarily from wells completed in unconsolidated-deposit aquifers that consist mostly of sand and gravel, and from wells

  18. Evaluation of acute copper toxicity to larval fathead minnows (Pimephales promelas) in soft surface waters.

    Science.gov (United States)

    Van Genderen, Eric J; Ryan, Adam C; Tomasso, Joseph R; Klaine, Stephen J

    2005-02-01

    The hardness-based regulatory approach for Cu prescribes an extrapolation of the toxicity-versus-hardness relationship to low hardness (hardness surface waters. Seasonal water sampling was conducted at 24 sites throughout South Carolina, USA, to determine the site-specific influences of soft surface-water conditions on acute Cu toxicity. Concurrent toxicity tests in laboratory water, matched for hardness and alkalinity (modified method), also were conducted to allow calculation of water-effect ratios (WERs). In addition, tests were conducted at recommended hardness levels (recommended method) for comparison of WER methodology in soft water. Surface-water conditions (average+/-standard deviation, n = 53) were hardness of 16+/-8 mg/L as CaCO3, alkalinity of 18+/-11 mg/L as CaCO3, and dissolved organic carbon of 6+/-4 mg/L. Dissolved Cu 48-h median lethal concentration (LC50) values varied nearly 45-fold across the dataset and greater than four-fold at individual sites. Spatial (p hardness-based equation for Cu at 50 mg/L or less as CaCO3 would adequately protect fathead minnow populations in soft surface waters. The WER results presented here demonstrate the inconsistency between hardness-based criteria and the methodology for deriving site-specific water-quality criteria in low-hardness waters.

  19. Grooved organogel surfaces towards anisotropic sliding of water droplets.

    Science.gov (United States)

    Zhang, Pengchao; Liu, Hongliang; Meng, Jingxin; Yang, Gao; Liu, Xueli; Wang, Shutao; Jiang, Lei

    2014-05-21

    Periodic micro-grooved organogel surfaces can easily realize the anisotropic sliding of water droplets attributing to the formed slippery water/oil/solid interface. Different from the existing anisotropic surfaces, this novel surface provides a versatile candidate for the anisotropic sliding of water droplets and might present a promising way for the easy manipulation of liquid droplets for water collection, liquid-directional transportation, and microfluidics.

  20. Willingness to pay for water and water rights definition: study among smallholder irrigators in Limpopo Province, South Africa

    NARCIS (Netherlands)

    Speelman, S.; Haese, D' M.F.C.; Frija, A.; Farolfi, S.; Haese, D' L.

    2009-01-01

    Internationally there is growing understanding that water rights are important and that a lack of effective water rights systems creates major problems for the management of increasingly scarce water supplies. In South Africa the smallholder irrigation sector faces two major challenges. Firstly

  1. Willingness to pay for water and water rights definition: study among smallholder irrigators in Limpopo Province, South Africa

    NARCIS (Netherlands)

    Speelman, S.; Haese, D' M.F.C.; Frija, A.; Farolfi, S.; Haese, D' L.

    2009-01-01

    Internationally there is growing understanding that water rights are important and that a lack of effective water rights systems creates major problems for the management of increasingly scarce water supplies. In South Africa the smallholder irrigation sector faces two major challenges. Firstly wate

  2. The impact of the water rights definition on smallholder irrigators' willingness to pay for water in Limpopo province, South Africa

    NARCIS (Netherlands)

    Speelman, S.; Farolfi, S.; Haese, D' M.F.C.; Frija, A.; Haese, D' L.

    2010-01-01

    Water rights are currently receiving increased attention from scholars and policymakers due to the growing understanding that ill-defined water rights impair efficient use. In South Africa, smallholder irrigation faces problems of low water use efficiency and cost recovery of government investments.

  3. Seasonal variation and partitioning of endocrine disrupting chemicals in waters and sediments of the Pearl River system, South China.

    Science.gov (United States)

    Gong, Jian; Duan, Dandan; Yang, Yu; Ran, Yong; Chen, Diyun

    2016-12-01

    Endocrine disrupting chemicals (EDCs) were seasonally investigated in surface water, suspended particulate matter, and sediments of the Pearl River Delta (PRD), South China. EDC concentrations in the surface water were generally higher in the summer than in winter. The surface water in the investigated rivers was heavily contaminated by the phenolic xenoestrogens. Moreover, the in-situ log Ksoc and log Kpoc values and their regression with log Kow in the field experiments suggest that binding mechanisms other than hydrophobic interaction are present for the sedimentary organic carbon and particulate organic carbon (SOC/POC). The logKsoc-logKow and logKpoc-logKow regression analyses imply that higher complexity of nonhydrophobic interactions with EDCs is present on the SOC samples comparing with the POC samples, which is related to their different sources.

  4. Petroleum pollutant degradation by surface water microorganisms.

    Science.gov (United States)

    Antić, Malisa P; Jovancićević, Branimir S; Ilić, Mila; Vrvić, Miroslav M; Schwarzbauer, Jan

    2006-09-01

    It is well known that the composition of petroleum or some of its processing products changes in the environment mostly under the influence of microorganisms. A series of experiments was conducted in order to define the optimum conditions for an efficient biodegradation of petroleum pollutant, or bioremediation of different segments of the environment. The aim of these investigations was to show to what extent the hydrocarbons of a petroleum pollutant are degraded by microbial cultures which were isolated as dominant microorganisms from a surface water of a wastewater canal of an oil refinery and a nitrogen plant. Biodegradation experiments were conducted on one paraffinic, and one naphthenic type of petroleum during a three month period under aerobic conditions, varying the following parameters: Inorganic (Kp) or an organic medium (Bh) with or without exposition to light. Microorganisms were analyzed in a surface water sample from a canal (Pancevo, Serbia), into which wastewater from an oil refinery and a nitrogen plant is released. The consortia of microorganisms were isolated from the water sample (most abundant species: Phormidium foveolarum--filamentous Cyanobacteria, blue-green algae and Achanthes minutissima, diatoms, algae). The simulation experiments of biodegradation were conducted with the biomass suspension and crude oils Sirakovo (Sir, paraffinic type) and Velebit (Ve, naphthenic type). After a three month period, organic substance was extracted by means of chloroform. In the extracts, the content of saturated hydrocarbons, aromatic hydrocarbons, alcohols and fatty acids was determined (the group composition). n-Alkanes and isoprenoid aliphatic alkanes, pristane and phytane, in the aliphatic fractions, were analyzed using gas chromatography (GC). Total isoprenoid aliphatic alkanes and polycyclic alkanes of sterane and triterpane types were analyzed by GC-MS. Paraffinic type petroleums have a significant loss of saturated hydrocarbons. For naphthenic

  5. Diurnal variations in water vapor over Central and South America

    Science.gov (United States)

    Meza, Amalia; Mendoza, Luciano; Bianchi, Clara

    2016-07-01

    Diurnal variations in atmospheric integrated water vapor (IWV) are studied employing IWV estimates, with a 30 minutes sampling rate, derived from Global Navigation Satellite Systems (GNSS) observations during the period 2007-2013. The analysis was performed in 73 GNSS tracking sites (GPS + GLONASS) which have more than 5 years of data. The selected area involves different climate types, from polar to tropical, with different diurnal variations of the integrated total humidity content. There are many processes that could induce diurnal variations in atmospheric water vapor (Dai et al, 1999 a,b), the most relevant causes are: surface evapotranspiration, atmospheric large-scale vertical motion, atmospheric low-level moisture convergence and precipitation and vertical mixing (which affects the vertical distribution of water vapor but does not affect the IWV). The numerical tools, Singular Value Decomposition and classical Multidimensional Scaling methods, are used to study these variations, considering the measurements made at each stations, as sample in the analysis. The aim of this investigation is to identify the IWV variability with respect to the local time associated to the different climate regions. In order to improve our analysis, all available weather information, such as radiosondes measurements (which are few), measurements of pressure and temperature and Numerical Weather Models reanalysis data, are used. Reference: Dai, A., K. E. Trenberth, and T. R. Karl, 1999 a: Effects of clouds, soil moisture, precipitation and water vapor on diurnal temperature range. J. Climate, 12, 2451-2473. Dai, A., F. Giorgi, and K. E. Trenberth, 1999 b: Observed and model simulated precipitation diurnal cycle over the contiguous United States.J. Geophys. Res., 104, 6377-6402. KEYWORDS: water vapor, diurnal cycle, GNSS

  6. Public Perception of Potable Water Supply in Abeokuta South west ...

    African Journals Online (AJOL)

    The perception of residents towards the supply of potable water to Abeokuta was ... water related diseases as a result of the consumption of drinking water ... who relied on water from alternative sources subjected the water to treatment before ...

  7. 南海及临近海域黄鳍金枪鱼渔场时空分布与海表温度的关系%Relationship between temporal-spatial distribution of yellowfin tuna Thunnus albacares fishing grounds and sea surface temperature in the South China Sea and adjacent waters

    Institute of Scientific and Technical Information of China (English)

    纪世建; 周为峰; 王鲁民; 唐峰华; 吴祖立; 陈国宝

    2016-01-01

    为得到南海及临近海域黄鳍金枪鱼(Thunnus albacores)渔场最适宜栖息海表温度(SST)范围,基于美国国家海洋大气局(NOAA )气候预测中心月平均海表温度(SST)资料,结合中西太平洋渔业委员会(WCPFC)发布的南海及临近海域金枪鱼延绳钓渔业数据,绘制了月平均SST和月平均单位捕捞努力量渔获量(CPUE)的空间叠加图,用于分析南海及临近海域黄鳍金枪鱼渔场CPUE时空分布和SST的关系.结果表明,南海及临近海域黄鳍金枪鱼CPUE在16 ℃~31 ℃均有分布.在春季和夏季(3 ~8 月),位于10°~20°N的大部分渔区CPUE较高,其南北侧CPUE较低;而到了秋季和冬季(9月到次年2月),高产渔场区域会向南拓宽.CPUE在各SST区间的散点图呈现出明显的负偏态分布,高CPUE主要集中在26 ℃~30 ℃,最高值出现在29℃附近;在22 ℃ ~26 ℃范围内 CPUE散点分布较为零散,但在这个范围也会出现相当数量的高CPUE;在22 ℃以下的CPUE几乎属于低CPUE和零CPUE;零CPUE的平均SST为26 .7 ℃(±3 .2 ℃),低CPUE的平均SST为27.8 ℃(±2.1 ℃),高CPUE的平均SST为28.4℃(±1.5 ℃),高CPUE在各SST区间的分布要比零CPUE和低CPUE更为集中.采用频次分析和经验累积分布函数计算其最适SST范围,得到南海及临近海域黄鳍金枪鱼最适SST为26 .9 ℃~29 .4 ℃.本研究初步得到南海及临近海域黄鳍金枪鱼中心渔场时空分布特征及SST适宜分布区间,可为开展南海及临近海域金枪鱼渔情预报工作提供理论依据和参考.%South China Sea is an important yellowfin tuna Thunnus albacares longline fishing ground in China. There is little research on relationship between the temporal-spatial distribution of yellowfin tuna fishing grounds and sea surface temperature (SST)environment in the South China Sea and its adjacent waters. Based on the monthly averaged SST data provided by the Climate Prediction Center of the National Oceanic and Atmospheric

  8. Dynamics of the water circulations in the southern South China Sea and its seasonal transports

    DEFF Research Database (Denmark)

    Daryabor, Farshid; Ooi, See Hai Ooi; Samah, Azizan Abu

    2016-01-01

    A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re......-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast...... circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China...

  9. Improving precipitation simulation from updated surface characteristics in South America

    Science.gov (United States)

    Pereira, Gabriel; Silva, Maria Elisa Siqueira; Moraes, Elisabete Caria; Chiquetto, Júlio Barboza; da Silva Cardozo, Francielle

    2016-04-01

    Land use and land cover maps and their physical-chemical and biological properties are important variables in the numerical modeling of Earth systems. In this context, the main objective of this study is to analyze the improvements resulting from the land use and land cover map update in numerical simulations performed using the Regional Climate Model system version 4 (RegCM4), as well as the seasonal variations of physical parameters used by the Biosphere Atmosphere Transfer Scheme (BATS). In general, the update of the South America 2007 land use and land cover map, used by the BATS, improved the simulation of precipitation by 10 %, increasing the mean temporal correlation coefficient, compared to observed data, from 0.84 to 0.92 (significant at p Pantanal wetlands); (3) in the Northeast region of Brazil; (4) in northwestern Paraguay; and (5) in the River Plate Basin, in Argentina. Moreover, the main precipitation differences between sensitivity and control experiments occurred during the rainy months in central-north South America (October to March). These were associated with a displacement in the South Atlantic convergence zone (SACZ) positioning, presenting a spatial pattern of alternated areas with higher and lower precipitation rates. These important differences occur due to the replacement of tropical rainforest for pasture and agriculture and the replacement of agricultural areas for pasture, scrubland, and deciduous forest.

  10. Atmospheric Water Harvesting: Role of Surface Wettability and Edge Effect

    KAUST Repository

    Jin, Yong

    2017-06-23

    Atmospheric water is emerging as an important potable water source. The present work experimentally and theoretically investigates water condensation and collection on flat surfaces with contrasting contact angles and contact angle hysteresis (CAH) to elucidate their roles on water mass collection efficiency. The experimental results indicate that a hydrophilic surface promotes nucleation and individual droplets growth, and a surface with a low CAH tends to let a smaller droplet to slide down, but the overall water mass collection efficiency is independent of both surface contact angle and CAH. The experimental results agree well with our theoretical calculations. During water condensation, a balance has to be struck between single droplet growth and droplet density on a surface so as to maintain a constant water droplet surface coverage ratio, which renders the role of both surface wettability and hysteresis insignificant to the ultimate water mass collection. Moreover, water droplets on the edges of a surface grow much faster than those on the non-edge areas and thus dominate the contribution to the water mass collection by the entire surface, directly pointing out the very important role of edge effect on water condensation and collection.

  11. Adsorbed water on iron surface by molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, F.W.; Campos, T.M.B.; Cividanes, L.S., E-mail: flaviano@ita.br; Simonetti, E.A.N.; Thim, G.P.

    2016-01-30

    Graphical abstract: - Highlights: • We developed a new force field to describe the Fe–H{sub 2}O interaction. • We developed a new force field to describe the flexible water model at low temperature. • We analyze the orientation of water along the iron surface. • We calculate the vibrational spectra of water near the iron surface. • We found a complex relationship between water orientation and the atomic vibrational spectra at different sites of adsorption along the iron surface. - Abstract: The adsorption of H{sub 2}O molecules on metal surfaces is important to understand the early process of water corrosion. This process can be described by computational simulation using molecular dynamics and Monte Carlo. However, this simulation demands an efficient description of the surface interactions between the water molecule and the metallic surface. In this study, an effective force field to describe the iron-water surface interactions was developed and it was used in a molecular dynamics simulation. The results showed a very good agreement between the simulated vibrational-DOS spectrum and the experimental vibrational spectrum of the iron–water interface. The water density profile revealed the presence of a water double layer in the metal interface. Furthermore, the horizontal mapping combined with the angular distribution of the molecular plane allowed the analysis of the water structure above the surface, which in turn agrees with the model of the double layer on metal surfaces.

  12. Research of water resources allocation of South-to-North Water Diversion East Route Project in Jiangsu Province ,Eastern China

    Science.gov (United States)

    Zeng, C.

    2015-12-01

    Optimized allocation of water resources is the important means of solving regional water shortage and can improve the utilization of water resources. Water resources allocation in the large-scale water diversion project area is the current research focus. This research takes the east route of the South-to-North Water Transfer Project in Jiangsu province as the research area, based on the hydrological model, agricultural irrigation quota model, and water project scheduling model, a water resources allocation model was constructed. The research carried on generalized regional water supply network, simulated the water supply, water demand and water deficit in agriculture, industry, life, ecology and lock under the status quo and planning engineering conditions. According to the results, the east route of the South-to-North Water Transfer Project is helpful to improve regional water shortage situation. The results showed that pump output increase by 2.8 billion cubic meters of water. On the conditions of P = 95%, 75% and 50%, compared with the benchmark year, water demand increases slightly due to the need of social and economic development in planning years, and water supply increased significantly because of new diversion ability. Water deficit are greatly reduced by 74.9% especially in the commonly drought condition because of the new project operation and optimized allocation of water resources.

  13. 40 CFR 258.27 - Surface water requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Surface water requirements. 258.27... FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.27 Surface water requirements. MSWLF... wetlands, that violates any requirements of the Clean Water Act, including, but not limited to,...

  14. Floating Vegetated Mats For Improving Surface Water Quality

    Science.gov (United States)

    Contamination of surface and ground waters is an environmental concern. Pollution from both point and nonpoint sources can render water unsuitable for use. Surface waters of concern include streams, rivers, ponds, lakes, canals, and wastewater lagoons. Lagooned wastewater from confined animal feedi...

  15. Lithium content in potable water, surface water, ground water, and mineral water on the territory of Republic of Macedonia

    Directory of Open Access Journals (Sweden)

    Vesna Kostik

    2014-07-01

    Full Text Available The aim of this study was to determine lithium concentration in potable water, surface water, ground, and mineral water on the territory of the Republic of Macedonia. Water samples were collected from water bodies such as multiple public water supply systems located in 13 cities, wells boreholes located in 12 areas, lakes and rivers located in three different areas. Determination of lithium concentration in potable water, surface water was performed by the technique of inductively coupled plasma-mass spectrometry, while in ground water samples from wells boreholes and mineral waters with the technique of ion chromatography. The research shows that lithium concentration in potable water ranging from 0.1 to 5.2 μg/L; in surface water from 0.5 to 15.0 μg/L; ground water from wells boreholes from 16.0 to 49.1 μg/L and mineral water from 125.2 to 484.9 μg/L. Obtained values are in accordance with the relevant international values for the lithium content in water.

  16. Saline Indian Ocean waters invaded the South Atlantic thermocline during glacial termination II

    NARCIS (Netherlands)

    Scussolini, P.; Scussolini, G.; Brummer, G.-J.A.; Peeters, F.J.C.

    2015-01-01

    Salty and warm Indian Ocean waters enter the South Atlantic via the Agulhas leakage, south of Africa. Model simulations and proxy evidence of Agulhas leakage strengthening during glacial terminations led to the hypothesis that it was an important modulator of the Atlantic Ocean circulation. Yet, the

  17. Constitutional Court of South Africa overturns lower court's decision on the right to "sufficient water".

    Science.gov (United States)

    2009-12-01

    On 8 October 2009, the Constitutional Court of South Africa overturned the judgment of the Supreme Court of Appeal, which addressed the proper interpretation of Section 27(1)(b) of the Constitution of South Africa (Constitution)--namely, everyone's right to have access to sufficient water.

  18. Water Policy Reforms in South Korea: A Historical Review and Ongoing Challenges for Sustainable Water Governance and Management

    Directory of Open Access Journals (Sweden)

    Ik-Chang Choi

    2017-09-01

    Full Text Available This study aims to provide an opinion on the state-of-the-art of changes and reforms of water policies in South Korea, as well as the challenges along with their implications for sustainable water governance and management. In parallel with change in water resource characteristics generated by physical, environmental and socio-economic challenges such as: (1 uncertainties about climate change (flooding and drought including seasonal and regional variation in precipitation; (2 significant increase in water use caused by rapid urbanization and population growth in industrialized urban areas; (3 inadequate water pricing mechanism which covers only around 80% of the production cost and makes it harder to maintain water systems; and (4 recursive water quality degradation and conflicts over water rights between regions resulting from non-point source pollution in highland versus lowland areas, Korean water policies have been developed through diverse reforms over 100 years. Nevertheless, new challenges for sustainable water management are continuously emerging. To meet those challenges we provide two ideas: (i provider-gets-principle (payment for ecosystem services of cost-benefit sharing among stakeholders who benefit from water use; and (ii water pricing applying full-cost pricing-principle internalizing environmental externalities caused by the intensive water use. Funds secured from the application of those methods would facilitate: (1 support for upstream (rural low income householders suffering from economic restrictions; (2 improvement in water facilities; and (3 efficient water use and demand management in South Korea’s water sectors. We expect that this paper can examine the lessons relevant to challenges that South Korea faces and offer some implications on the formulation of new integration and further reforms of the institutions, laws and organizations responsible for managing water resources in South Korea.

  19. Characteristics of nitrogen forms in the surface sediments of southwestern Nansha Trough, South China Sea

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The area of the southwestern Nansha Trough is one of the most productive areas of the southern South China Sea. It is a typical semi-deep sea area of transition from shoal to abyssal zone. To understand distributions and roles of nitrogen forms involved in biogeochemical cycling in this area, contents of nitrogen in four extractable forms: nitrogen in ion exchangeable form (IEF-N), nitrogen in weak acid extractable form (WAEF-N), nitrogen in strong alkali extractable form (SAEF-N) and nitrogen in strong oxidation extractable form (SOEF-N), as well as in total nitrogen content (TN) in surface sediments were determined from samples collected from the cruise in April - May 1999. The study area was divided into three regions (A, B and C) in terms of clay sediment (60%, respectively. Generally, region C was the richest in the nitrogen of all forms and region A the poorest, indicating that the finer the grain size is, the richer the contents of various nitrogen are. The burial efficiency of total nitrogen in surface sediments was 28.79%, indicating that more than 70% of nitrogen had been released and participated in biogeochemical recycling through sediment-water interface.

  20. How to repel hot water from a superhydrophobic surface?

    KAUST Repository

    Yu, Zhejun

    2014-01-01

    Superhydrophobic surfaces, with water contact angles greater than 150° and slide angles less than 10°, have attracted a great deal of attention due to their self-cleaning ability and excellent water-repellency. It is commonly accepted that a superhydrophobic surface loses its superhydrophobicity in contact with water hotter than 50 °C. Such a phenomenon was recently demonstrated by Liu et al. [J. Mater. Chem., 2009, 19, 5602], using both natural lotus leaf and artificial leaf-like surfaces. However, our work has shown that superhydrophobic surfaces maintained their superhydrophobicity, even in water at 80 °C, provided that the leaf temperature is greater than that of the water droplet. In this paper, we report on the wettability of water droplets on superhydrophobic thin films, as a function of both their temperatures. The results have shown that both the water contact and slide angles on the surfaces will remain unchanged when the temperature of the water droplet is greater than that of the surface. The water contact angle, or the slide angle, will decrease or increase, however, with droplet temperatures increasingly greater than that of the surfaces. We propose that, in such cases, the loss of superhydrophobicity of the surfaces is caused by evaporation of the hot water molecules and their condensation on the cooler surface. © 2014 the Partner Organisations.

  1. MODELING OF WATER DYNAMICS AND POLLUTANT SPREADING IN THE LUOMAHU RESERVOIR FOR WATER TRANSFER FORM SOUTH TO NORTH OF CHINA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Water quality is the key problem of the East-Line Project of Water Transfer from South to North China. In this paper, the principles of a 1D and 2D-integrated mathematical model for describing the dynamics of water in a flow-through river, canals and lakes was worked out. The numerical method and model algorithm were developed. The efficiency of the model was estimated by applying it to studying water dynamics in the Luomahu reservoir and simulating the spreading process of a polluted water mass and the evolution of the concentration. The results of calculations are used to assess water environmental quality and to manage water resource in the Luomahu reservoir and the Jinghang-Canal for the Project of Water Transfer from South to North China.

  2. Estimating water losses as a result of food waste in South Africa

    CSIR Research Space (South Africa)

    Oelofse, Suzanna HH

    2013-09-01

    Full Text Available Globally there are sufficient land and water resources to produce food over the next 50 years, but only if water for agriculture is better managed (Molden, 2007). Water is a critical and strategic natural resource in South Africa. It is essential...

  3. Structure and reactivity of water at biomaterial surfaces.

    Science.gov (United States)

    Vogler, E A

    1998-02-01

    Molecular self association in liquids is a physical process that can dominate cohesion (interfacial tension) and miscibility. In water, self association is a powerful organizational force leading to a three-dimensional hydrogen-bonded network (water structure). Localized perturbations in the chemical potential of water as by, for example, contact with a solid surface, induces compensating changes in water structure that can be sensed tens of nanometers from the point of origin using the surface force apparatus (SFA) and ancillary techniques. These instruments reveal attractive or repulsive forces between opposing surfaces immersed in water, over and above that anticipated by continuum theory (DLVO), that are attributed to a variable density (partial molar volume) of a more-or-less ordered water structure, depending on the water wettability (surface energy) of the water-contacting surfaces. Water structure at surfaces is thus found to be a manifestation of hydrophobicity and, while mechanistic/theoretical interpretation of experimental results remain the subject of some debate in the literature, convergence of experimental observations permit, for the first time, quantitative definition of the relative terms 'hydrophobic' and 'hydrophilic'. In particular, long-range attractive forces are detected only between surfaces exhibiting a water contact angle theta > 65 degrees (herein defined as hydrophobic surfaces with pure water adhesion tension tau O = gamma O cos theta 30 dyn/cm). These findings suggest at least two distinct kinds of water structure and reactivity: a relatively less-dense water region against hydrophobic surfaces with an open hydrogen-bonded network and a relatively more-dense water region against hydrophilic surfaces with a collapsed hydrogen-bonded network. Importantly, membrane and SFA studies reveal a discrimination between biologically-important ions that preferentially solubilizes divalent ions in more-dense water regions relative to less

  4. Distribution of {sup 129}I in terrestrial surface water environments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xuegao [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Gong, Meng [College of Hydrology and Water Resources, Hohai University, Nanjing (China); Yi, Peng, E-mail: pengyi1915@163.com [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Aldahan, Ala [Department of Earth Sciences, Uppsala University, Uppsala (Sweden); Department of Geology, United Arab Emirates University, Al Ain (United Arab Emirates); Yu, Zhongbo [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Possnert, Göran [Tandem Laboratory, Uppsala University, Uppsala (Sweden); Chen, Li [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China)

    2015-10-15

    The global distribution of the radioactive isotope iodine-129 in surface waters (lakes and rivers) is presented here and compared with the atmospheric deposition and distribution in surface marine waters. The results indicate relatively high concentrations in surface water systems in close vicinity of the anthropogenic release sources as well as in parts of Western Europe, North America and Central Asia. {sup 129}I level is generally higher in the terrestrial surface water of the Northern hemisphere compared to the southern hemisphere. The highest values of {sup 129}I appear around 50°N and 40°S in the northern and southern hemisphere, separately. Direct gaseous and marine atmospheric emissions are the most likely avenues for the transport of {sup 129}I from the sources to the terrestrial surface waters. To apply iodine-129 as process tracer in terrestrial surface water environment, more data are needed on {sup 129}I distribution patterns both locally and globally.

  5. Water content distribution in the surface layer of Maoping slope

    Institute of Scientific and Technical Information of China (English)

    LIU Yuewu; CHEN Huixin; LIU Qingquan; GONG Xin; ZHANG Dawei; LI Lianxiang

    2005-01-01

    The water content distribution in the surface layer of Maoping slope has been studied by testing the water content at 31 control sites. The water content profiles at these sites have also been determined. The water content distributions at different segments have been obtained by using the Kriging method of geostatistics. By comparing the water content distributions with the landform of the slope, it was shown that the water content is closely dependent on the landform of the slope. The water content distribution in the surface layer provided a fundamental basis for landslide predication and treatment.

  6. Effect of impervious surface area and vegetation changes on mean surface temperature over Tshwane metropolis, Gauteng Province, South Africa

    CSIR Research Space (South Africa)

    Adeyemi, A

    2015-11-01

    Full Text Available The Tshwane Metropolis, Gauteng Province, South Africa, continues to experience rapid urbanization as a result of population growth. This has led to the conversion of natural lands into large man-made landscapes i.e., increase in impervious surfaces...

  7. Proposed aesthetic/physical and inorganic drinking-water criteria for the Republic of South Africa

    CSIR Research Space (South Africa)

    Kempster, PL

    1985-01-01

    Full Text Available Using existing criteria from other countries, in conjunction with data on element toxicities and normal dietary intakes, drinking-water criteria for 56 aesthetic/physical and inorganic chemical determinants were proposed for South Africa....

  8. Four decades of water recycling in Atlantis (Western Cape, South Africa): Past, present and future

    CSIR Research Space (South Africa)

    Bugan, Richard DH

    2016-10-01

    Full Text Available The primary aquifer at Atlantis (Western Cape, South Africa) is ideally suited for water supply and the indirect recycling of urban stormwater runoff and treated domestic wastewater for potable purposes. The relatively thin, sloping aquifer requires...

  9. Section 11: Surface Water Pathway - Likelihood of Release

    Science.gov (United States)

    Surface water releases can include the threat to targets from overland flow of hazardous substances and from flooding or the threat from the release of hazardous substances to ground water and the subsequent discharge of contaminated ground w

  10. Conceptualizing Biopolitics: Citizen-State Interactions in the Securing of Water Services in South Africa.

    Science.gov (United States)

    Bulled, Nicola

    2015-01-01

    Despite constitutional obligations to provide clean water to all citizens in South Africa, access to water and related services remains highly contested. The discord between constitutional promises and lived realities of water access, particularly through national infrastructure, provides a platform on which to examine Foucauldian notions of biopolitics, the control of populations through technologies of governing. Drawing on the situations of residents in the rural Vhembe district in the north eastern corner of the country, I examine how individuals conceptualize the relationship that exists between citizen and state and the responsibilities of each in post-Apartheid South Africa as it relates to water access. In addition, I describe strategies employed throughout South Africa to voice rights to water and how these approaches are perceived. Finally, I consider how the three primary forms of 'water citizenship'-citizen, agent, and subject-influence the current and future health of vulnerable residents.

  11. Biofilm development on metal surfaces in tropical marine waters

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, F.P.; Bhosle, N.B.

    environments. However, little is known about biofilm bacteria developed on metal surfaces, especially immersed in tropical marine waters. Similarly, not much is known about the nature of organic matter deposited on the surfaces over the period of immersion...

  12. The glass-liquid transition of water on hydrophobic surfaces.

    Science.gov (United States)

    Souda, Ryutaro

    2008-09-28

    Interactions of thin water films with surfaces of graphite and vitrified room-temperature ionic liquid [1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF(6)])] were investigated using time-of-flight secondary ion mass spectrometry as a function of temperature and annealing time to elucidate the glass-liquid transition of water at the molecular level. Surface diffusion of water occurs at temperatures higher than 120 K, thereby forming three-dimensional clusters (a two-dimensional layer) on the [bmim][PF(6)] (graphite) surface. The hydrophobic effect of the surface decreases with increasing coverage of water; the bulklike properties evolve up to 40 ML, as evidenced by the occurrence of film dewetting at around the conventional glass transition temperature (140 K). Results also showed that aging is necessary for the water monolayer (a 40 ML water film) to dewet the graphite ([bmim][PF(6)]) surface. The occurrence of aging is explainable by the successive evolution of two distinct liquids during the glass-liquid transition: low density liquid is followed by supercooled liquid water. The water monolayer on graphite is characterized by the preferred orientation of unpaired OH groups toward the surface; this structure is arrested during the aging time despite the occurrence of surface diffusion. However, the water monolayer formed on the [bmim][PF(6)] surface agglomerates immediately after the commencement of surface diffusion. The structure of low density liquid tends to be arrested by the attractive interaction with the neighbors.

  13. Improving precipitation simulation from updated surface characteristics in South America

    Science.gov (United States)

    Pereira, Gabriel; Silva, Maria Elisa Siqueira; Moraes, Elisabete Caria; Chiquetto, Júlio Barboza; da Silva Cardozo, Francielle

    2017-07-01

    Land use and land cover maps and their physical-chemical and biological properties are important variables in the numerical modeling of Earth systems. In this context, the main objective of this study is to analyze the improvements resulting from the land use and land cover map update in numerical simulations performed using the Regional Climate Model system version 4 (RegCM4), as well as the seasonal variations of physical parameters used by the Biosphere Atmosphere Transfer Scheme (BATS). In general, the update of the South America 2007 land use and land cover map, used by the BATS, improved the simulation of precipitation by 10 %, increasing the mean temporal correlation coefficient, compared to observed data, from 0.84 to 0.92 (significant at p < 0.05, Student's t test). Correspondingly, the simulations performed with adjustments in maximum fractional vegetation cover, in visible and shortwave infrared reflectance, and in the leaf area index, showed a good agreement for maximum and minimum temperature, with values closer to observed data. The changes in physical parameters and land use updating in BATS/RegCM4 reduced overestimation of simulated precipitation from 19 to 7 % (significant at p < 0.05, Student's t test). Regarding evapotranspiration and precipitation, the most significant differences due to land use updating were located (1) in the Amazon deforestation arc; (2) around the Brazil-Bolivia border (in the Brazilian Pantanal wetlands); (3) in the Northeast region of Brazil; (4) in northwestern Paraguay; and (5) in the River Plate Basin, in Argentina. Moreover, the main precipitation differences between sensitivity and control experiments occurred during the rainy months in central-north South America (October to March). These were associated with a displacement in the South Atlantic convergence zone (SACZ) positioning, presenting a spatial pattern of alternated areas with higher and lower precipitation rates. These important differences occur due to the

  14. Incorporating water consumption into crop water footprint: A case study of China's South-North Water Diversion Project.

    Science.gov (United States)

    Wei, Yuhang; Tang, Deshan; Ding, Yifan; Agoramoorthy, Govindasamy

    2016-03-01

    The crop water footprint (WF) indicates the consumption of water for a crop during the planting period, mainly through evapotranspiration. However, as irrigated agriculture accounts for nearly 25% of the global agriculture water usage, evaluation of WF during transportation becomes essential to improve the efficiency of irrigated agriculture. This study aims at building an improved WF model to understand how much WF is produced due to water diversion and how much crop WF increases during the transfer. The proposed model is then used to calculate the WF of four major crops in five provinces along China's South-North Water Transfer Project in two steps. First, the WF of the water transfer project (WFeng) is assessed in a supply chain analysis method. Second, a WF allocation model is built to distribute the project WF for each crop/province. The results show that the evaporation and seepage are the main sources of WFeng. Out of five provinces, two namely Tianjin and Hebei present higher WFblue and WF increase. A positive correlation between water diversion distance and crop WF increase is noted. Among the four crops, cotton presents higher WFblue and WF increase. The crops with higher WFblue tend to be more strongly influenced by the water diversion project, due to high irrigation water dependency. This analysis may expand the WF concept from an evaporation-related term to a term reflecting crop biological processes and water consumption by artificial irrigation projects. Thus, it may serve as an indicator for optimizing future objectives and strategies associated to water resource planning in China and elsewhere.

  15. Conjunctive Surface Water and Groundwater Management under Climate Change

    Directory of Open Access Journals (Sweden)

    Xiaodong eZhang

    2015-09-01

    Full Text Available Climate change can result in significant impacts on regional and global surface water and groundwater resources. Using groundwater as a complimentary source of water has provided an effective means to satisfy the ever-increasing water demands and deal with surface water shortages problems due to robust capability of groundwater in responding to climate change. Conjunctive use of surface water and groundwater is crucial for integrated water resources management. It is helpful to reduce vulnerabilities of water supply systems and mitigate the water supply stress in responding to climate change. Some critical challenges and perspectives are discussed to help decision/policy makers develop more effective management and adaptation strategies for conjunctive water resources use in facing climate change under complex uncertainties.

  16. Management of water extremes: A South African perspective on guidelines for policy and strategy development

    Directory of Open Access Journals (Sweden)

    MF Viljoen

    2015-01-01

    Full Text Available This presentation endeavours to present some guidelines for policy and strategy development with regard to the effective management of floods and droughts. Insights are gained from a literature study about the social, economic and political impacts of irrigation droughts, research done on the impacts and management of floods and water restrictions in South Africa as well as analysing the disaster management policy process in South Africa since 1994. The South African experience in terms of the management of water extremes, serves as basis for policy and strategy development and should benefit all involved – including other regions.

  17. Region 9 Surface Water Intakes (SDWIS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — EPAâ??s Safe Drinking Water Information System (SDWIS) databases store information about drinking water. The federal version (SDWIS/FED) stores the information EPA...

  18. Water, stakeholders and common ground : challenges for multi-stakeholder platforms in water resource management in South Africa

    NARCIS (Netherlands)

    Simpungwe, E.

    2006-01-01

    There is a growing global concern about future water supplies. Growing demands from agriculture, industry and urban growth are streching available water supplies while pollution is undermining the quality of the resource base. Physical data available indicate that in South Africa, full utilisation o

  19. COMMUNITY PARTICIPATION IN SURFACE WATER HARVESTING ...

    African Journals Online (AJOL)

    USER

    2014-11-25

    Nov 25, 2014 ... There is seasonal water scarcity in Marigat Division and the water demand has been ... with improved storage and rainwater harvesting methods. Such water can be ..... in the planning process and decision making and this ... The organizations support the community ... systems for domestic uses in urban.

  20. Planning for Water Resources of South Florida: A system dynamics modeling approach

    Science.gov (United States)

    Ahmad, S.

    2006-12-01

    With enormous growth in population, changes in land use, substantial agriculture activity, and need to protect vital environmental resources such as Everglades, south Florida presents a very challenging case for water resources planning. Working with stakeholders to meet challenges of water resources planning in south Florida, we are exploring important questions: (a) What are some major changes in terms of population growth, land use, water demand, and water availability that can be expected in south Florida in the short and long term?; (b) What would be the major hydrologic effects of climate variability and change on south Florida's water system?; (c) How could Florida's water system adapt to anticipated population growth, urban sprawl, and climate change?; and (d) What are the most promising (cost effective) policies for south Florida's water management in response to growth and climate change? We are developing a decision support (DS) framework, using system dynamics modeling approach, to evaluate and compare different short and long term water management policies. Besides climate information, the integrated DS framework considers other major factors that influence water demand and availability including: demographic changes, land use changes, economy, and environment. We analyze how increased or better use of climate information can lead to better, more cost-effective decisions for sustainable management of water resources. Using games/scenarios involving decision makers, we evaluate cost-effectiveness of different policy choices for short and long term water management in the region. We evaluate policies based on both demand side management through efficiency and conservation (low flow appliances, xeriscaping, pricing) and supply side management (desalination, water reuse). The outcome is a framework for exploring cost-effectiveness of alternative water management policies. The research advances work on water resources planning considering the impacts of

  1. An ontology design pattern for surface water features

    Science.gov (United States)

    Sinha, Gaurav; Mark, David; Kolas, Dave; Varanka, Dalia; Romero, Boleslo E.; Feng, Chen-Chieh; Usery, E. Lynn; Liebermann, Joshua; Sorokine, Alexandre

    2014-01-01

    Surface water is a primary concept of human experience but concepts are captured in cultures and languages in many different ways. Still, many commonalities exist due to the physical basis of many of the properties and categories. An abstract ontology of surface water features based only on those physical properties of landscape features has the best potential for serving as a foundational domain ontology for other more context-dependent ontologies. The Surface Water ontology design pattern was developed both for domain knowledge distillation and to serve as a conceptual building-block for more complex or specialized surface water ontologies. A fundamental distinction is made in this ontology between landscape features that act as containers (e.g., stream channels, basins) and the bodies of water (e.g., rivers, lakes) that occupy those containers. Concave (container) landforms semantics are specified in a Dry module and the semantics of contained bodies of water in a Wet module. The pattern is implemented in OWL, but Description Logic axioms and a detailed explanation is provided in this paper. The OWL ontology will be an important contribution to Semantic Web vocabulary for annotating surface water feature datasets. Also provided is a discussion of why there is a need to complement the pattern with other ontologies, especially the previously developed Surface Network pattern. Finally, the practical value of the pattern in semantic querying of surface water datasets is illustrated through an annotated geospatial dataset and sample queries using the classes of the Surface Water pattern.

  2. Adsorption mechanism of water molecule on goethite (010) surface

    Science.gov (United States)

    Xiu, Fangyuan; Zhou, Long; Xia, Shuwei; Yu, Liangmin

    2016-12-01

    Goethite widely exists among ocean sediments; it plays an important role in fixing heavy metals and adsorbing organic contaminants. So the understanding of the adsorbing process of water molecule on its surface will be very helpful to further reveal such environmental friendly processes. The configuration, electronic properties and interaction energy of water molecules adsorbed on pnma goethite (010) surface were investigated in detail by using density functional theory on 6-31G (d,p) basis set and projector- augment wave (PAW) method. The mechanism of the interaction between goethite surface and H2O was proposed. Despite the differences in total energy, there are four possible types of water molecule adsorption configurations on goethite (010) surface (Aa, Ab, Ba, Bb), forming coordination bond with surface Fe atom. Results of theoretical modeling indicate that the dissociation process of adsorbed water is an endothermic reaction with high activation energy. The dissociation of adsorbed water molecule is a proton transportation process between water's O atoms and surface. PDOS results indicate that the bonding between H2O and (010) surface is due to the overlapping of water's 2p orbitals and Fe's 3d orbitals. These results clarify the mechanism on how adsorbed water is dissociated on the surface of goethite and potentially provide useful information of the surface chemistry of goethite.

  3. Prediction of solar global radiation on a surface tilted to the south

    Science.gov (United States)

    Kudish, Avraham I.; Evseev, Efim G.

    2008-08-01

    Solar global and diffuse radiation intensities are, in general, measured on horizontal surfaces, whereas stationary solar conversion systems (both flat plate solar collector and PV) are tilted towards the sun in order to maximize the amount of solar radiation incident on the collector surface. Consequently, the solar radiation incident on a surface tilted to the south (northern hemisphere) must be determined by converting the solar radiation intensities measured on a horizontal surface to that incident on the tilted surface of interest. There exist a large number of models designed to perform such a conversion. Eleven such models have been tested utilizing data measured in Beer Sheva, Israel. The data consist of hourly solar global and diffuse radiation on a horizontal surface, normal incidence beam and global radiation on a south-oriented surface tilted at 40°. The individual model performance is assessed by an inter-comparison between the calculated and measured solar global radiation on the south-oriented surface tilted at 40° using both graphical and statistical methods. The relative performance of the different models under different sky conditions, i.e., clear, partially cloudy and cloudy as defined by the hourly clearness index value, has been studied.

  4. Water poverty and rural development: Evidence from South Africa

    CSIR Research Space (South Africa)

    Matshe, I

    2013-08-01

    Full Text Available link between household water and economic poverty of rural households, with households’ total monthly income used as an indicator of economic poverty. An adaptation of a comprehensive water poverty index, which considers water access, quality, use...

  5. Quantification of water usage at a South African platinum processing ...

    African Journals Online (AJOL)

    water use will also lessen the dependence of mining opera- tions on water resources ..... available for the water footprints of the chemicals and electricity used within the process. ... A list of tasks, stores and treatment plants was also provided.

  6. Infiltration of pesticides in surface water into nearby drinking water supply wells

    DEFF Research Database (Denmark)

    Malaguerra, Flavio; Albrechtsen, Hans-Jørgen; Binning, Philip John

    Drinking water wells are often placed near streams because streams often overly permeable sediments and the water table is near the surface in valleys, and so pumping costs are reduced. The lowering of the water table by pumping wells can reverse the natural flow from the groundwater to the stream......, inducing infiltration of surface water to groundwater and consequently to the drinking water well. Many attenuation processes can take place in the riparian zone, mainly due to mixing, biodegradation and sorption. However, if the water travel time from the surface water to the pumping well is too short......, or if the compounds are poorly degradable, contaminants can reach the drinking water well at high concentrations, jeopardizing drinking water quality. Here we developed a reactive transport model to evaluate the risk of contamination of drinking water wells by surface water pollution. The model was validated using...

  7. 2-D NUMERICAL SIMULATION OF FLOODING EFFECTS CAUSED BY SOUTH-TO-NORTH WATER TRANSFER PROJECT

    Institute of Scientific and Technical Information of China (English)

    SUN Dong-po; XUE Hai; WANG Peng-tao; LU Rui-li; LIAO Xiao- long

    2008-01-01

    Since the General Channel designed for the South-to-North Water Transfer Project in China has to cross many rivers and streams flowing from west to east, there are potentially serious effects additional flooding on the westem side of the project alignment. Therefore, a 2-D numerical model for forecasting basin flood disasters was established and verified using historical flood data. The model was applied to researching the interaction between the proposed Project and flooding events for 5 streams in the Anyang River reach as a representative case study. Simulated results indicate that the model could correctly forecast the flood, submerged area and depths, and water surface elevations along the left side of the channel. The discharge capacity and location of hydraulic structures in the transfer canal alignment were analyzed. Then adjustments to the dimensions and positioning of proposed hydraulic structures were recommended at intersections, especially the addition of a channel to transfer flood water from one stream to another, which can effectively limit the sluice and protect the Anyang City from flooding.

  8. Simulation of water cluster assembly on a graphite surface.

    Science.gov (United States)

    Lin, C S; Zhang, R Q; Lee, S T; Elstner, M; Frauenheim, Th; Wan, L J

    2005-07-28

    The assembly of small water clusters (H2O)n, n = 1-6, on a graphite surface is studied using a density functional tight-binding method complemented with an empirical van der Waals force correction, with confirmation using second-order Møller-Plesset perturbation theory. It is shown that the optimized geometry of the water hexamer may change its original structure to an isoenergy one when interacting with a graphite surface in some specific orientation, while the smaller water cluster will maintain its cyclic or linear configurations (for the water dimer). The binding energy of water clusters interacting with graphite is dependent on the number of water molecules that form hydrogen bonds, but is independent of the water cluster size. These physically adsorbed water clusters show little change in their IR peak position and leave an almost perfect graphite surface.

  9. Surface Curvature-Induced Directional Movement of Water Droplets

    CERN Document Server

    Lv, Cunjing; Yin, Yajun; Zheng, Quanshui

    2010-01-01

    Here we report a surface curvature-induced directional movement phenomenon, based on molecular dynamics simulations, that a nanoscale water droplet at the outer surface of a graphene cone always spontaneously moves toward the larger end of the cone, and at the inner surface toward the smaller end. The analysis on the van der Waals interaction potential between a single water molecule and a curved graphene surface reveals that the curvature with its gradient does generate the driving force resulting in the above directional motion. Furthermore, we found that the direction of the above movement is independent of the wettability, namely is regardless of either hydrophobic or hydrophilic of the surface. However, the latter surface is in general leading to higher motion speed than the former. The above results provide a basis for a better understanding of many reported observations, and helping design of curved surfaces with desired directional surface water transportation.

  10. Sampling procedure for lake or stream surface water chemistry

    Science.gov (United States)

    Robert Musselman

    2012-01-01

    Surface waters collected in the field for chemical analyses are easily contaminated. This research note presents a step-by-step detailed description of how to avoid sample contamination when field collecting, processing, and transporting surface water samples for laboratory analysis.

  11. Models of Fate and Transport of Pollutants in Surface Waters

    Science.gov (United States)

    Okome, Gloria Eloho

    2013-01-01

    There is the need to answer very crucial questions of "what happens to pollutants in surface waters?" This question must be answered to determine the factors controlling fate and transport of chemicals and their evolutionary state in surface waters. Monitoring and experimental methods are used in establishing the environmental states.…

  12. Models of Fate and Transport of Pollutants in Surface Waters

    Science.gov (United States)

    Okome, Gloria Eloho

    2013-01-01

    There is the need to answer very crucial questions of "what happens to pollutants in surface waters?" This question must be answered to determine the factors controlling fate and transport of chemicals and their evolutionary state in surface waters. Monitoring and experimental methods are used in establishing the environmental states.…

  13. Shallow Water Propagation and Surface Reverberation Modeling

    Science.gov (United States)

    2014-07-29

    term goals were to 1. exploit measurements of breaking wave noise and photographic images of whitecaps to infer bubble cloud populations at the sea ...surface reverberation in wind-driven seas , an additional objective has been to study the role of sub-surface bubbles on the attenuation and scattering of...acoustic signals, including determining methods for quantifying bubble populations with video footage of the sea surface and developing models of

  14. Changes in Land Surface Water Dynamics since the 1990s and Relation to Population Pressure

    Science.gov (United States)

    Prigent, C.; Papa, F.; Aires, F.; Jimenez, C.; Rossow, W. B.; Matthews, E.

    2012-01-01

    We developed a remote sensing approach based on multi-satellite observations, which provides an unprecedented estimate of monthly distribution and area of land-surface open water over the whole globe. Results for 1993 to 2007 exhibit a large seasonal and inter-annual variability of the inundation extent with an overall decline in global average maximum inundated area of 6% during the fifteen-year period, primarily in tropical and subtropical South America and South Asia. The largest declines of open water are found where large increases in population have occurred over the last two decades, suggesting a global scale effect of human activities on continental surface freshwater: denser population can impact local hydrology by reducing freshwater extent, by draining marshes and wetlands, and by increasing water withdrawals. Citation: Prigent, C., F. Papa, F. Aires, C. Jimenez, W. B. Rossow, and E. Matthews (2012), Changes in land surface water dynamics since the 1990s and relation to population pressure, in section 4, insisting on the potential applications of the wetland dataset.

  15. Water-Mediated Interactions between Hydrophilic and Hydrophobic Surfaces.

    Science.gov (United States)

    Kanduč, Matej; Schlaich, Alexander; Schneck, Emanuel; Netz, Roland R

    2016-09-01

    All surfaces in water experience at short separations hydration repulsion or hydrophobic attraction, depending on the surface polarity. These interactions dominate the more long-ranged electrostatic and van der Waals interactions and are ubiquitous in biological and colloidal systems. Despite their importance in all scenarios where the surface separation is in the nanometer range, the origin of these hydration interactions is still unclear. Using atomistic solvent-explicit molecular dynamics simulations, we analyze the interaction free energies of charge-neutral model surfaces with different elastic and water-binding properties. The surface polarity is shown to be the most important parameter that not only determines the hydration properties and thereby the water contact angle of a single surface but also the surface-surface interaction and whether two surfaces attract or repel. Elastic properties of the surfaces are less important. On the basis of surface contact angles and surface-surface binding affinities, we construct a universal interaction diagram featuring three different interaction regimes-hydration repulsion, cavitation-induced attraction-and for intermediate surface polarities-dry adhesion. On the basis of scaling arguments and perturbation theory, we establish simple combination rules that predict the interaction behavior for combinations of dissimilar surfaces.

  16. Transport and scavenging of Pu in surface waters of the Southern Hemisphere Oceans

    DEFF Research Database (Denmark)

    Gastaud, J.; Povinec, P.P.; Aoyama, M.

    2011-01-01

    The distribution of 239Pu in Atlantic and Indian Ocean waters about four decades after their main injection from atmospheric nuclear weapons tests is discussed. Recent data obtained in the framework of the SHOTS (Southern Hemisphere Ocean Tracer Studies) projects are evaluated and compared...... with previous investigations. Seawater samples were collected during the round the globe BEAGLE2003 (Blue Ocean Global Expedition) along the 30°S transect in the Atlantic and the 20°S transect in the Indian Ocean. The results indicate transport of surface waters labelled with 239Pu from the western North...... Pacific via the Indonesian Seas to the South Indian Ocean and then to the South Atlantic Ocean. Along the whole BEAGLE2003 sampling route, the Atlantic Ocean has the lowest 239Pu content due to its particle scavenging on the long way from the western North Pacific. On the other hand, concentrations...

  17. Surface water quality assessment by environmetric methods.

    Science.gov (United States)

    Boyacioglu, Hülya; Boyacioglu, Hayal

    2007-08-01

    This environmetric study deals with the interpretation of river water monitoring data from the basin of the Buyuk Menderes River and its tributaries in Turkey. Eleven variables were measured to estimate water quality at 17 sampling sites. Factor analysis was applied to explain the correlations between the observations in terms of underlying factors. Results revealed that, water quality was strongly affected from agricultural uses. Cluster analysis was used to classify stations with similar properties and results distinguished three groups of stations. Water quality at downstream of the river was quite different from the other part. It is recommended to involve the environmetric data treatment as a substantial procedure in assessment of water quality data.

  18. A Screening-Level Hydroeconomic Model of South Florida Water Resources System

    Science.gov (United States)

    Mirchi, A.; Watkins, D. W., Jr.; Flaxman, M.; Wiesmann, D.

    2014-12-01

    South Florida's water resources management is characterized by system-wide tradeoffs associated with maintaining the ecological integrity of natural environments such as the Everglades while meeting the water demands of the agricultural sector and growing urban areas. As these tradeoffs become more pronounced due to pressures from climate change, sea level rise, and population growth, it will be increasingly challenging for policy makers and stakeholders to reach consensus on water resources management objectives and planning horizons. A hydroeconomic optimization model of south Florida's water resources system is developed to incorporate the value of water for preserving ecosystem services alongside water supplies to the Everglades Agricultural Area and urban areas. Results of this screening-level network flow model facilitate quantitative analysis and provide insights for long-term adaptive management strategies for the region's water resources.

  19. 40 CFR 257.3-3 - Surface water.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Surface water. 257.3-3 Section 257.3-3... and Practices § 257.3-3 Surface water. (a) For purposes of section 4004(a) of the Act, a facility... Water Act, as amended. (b) For purposes of section 4004(a) of the Act, a facility shall not cause...

  20. Freshening of Antarctic Intermediate Water in the South Atlantic Ocean in 2005-2014

    Science.gov (United States)

    Yao, Wenjun; Shi, Jiuxin; Zhao, Xiaolong

    2017-07-01

    Basin-scale freshening of Antarctic Intermediate Water (AAIW) is reported to have occurred in the South Atlantic Ocean during the period from 2005 to 2014, as shown by the gridded monthly means of the Array for Real-time Geostrophic Oceanography (Argo) data. This phenomenon was also revealed by two repeated transects along a section at 30° S, performed during the World Ocean Circulation Experiment Hydrographic Program. Freshening of the AAIW was compensated for by a salinity increase of thermocline water, indicating a hydrological cycle intensification. This was supported by the precipitation-minus-evaporation change in the Southern Hemisphere from 2000 to 2014. Freshwater input from atmosphere to ocean surface increased in the subpolar high-precipitation region and vice versa in the subtropical high-evaporation region. Against the background of hydrological cycle changes, a decrease in the transport of Agulhas Leakage (AL), which was revealed by the simulated velocity field, was proposed to be a contributor to the associated freshening of AAIW. Further calculation showed that such a decrease could account for approximately 53 % of the observed freshening (mean salinity reduction of about 0.012 over the AAIW layer). The estimated variability of AL was inferred from a weakening of wind stress over the South Indian Ocean since the beginning of the 2000s, which would facilitate freshwater input from the source region. The mechanical analysis of wind data here was qualitative, but it is contended that this study would be helpful to validate and test predictably coupled sea-air model simulations.

  1. Paradigms and theories in water governance: the case of South ...

    African Journals Online (AJOL)

    2016-01-01

    Jan 1, 2016 ... terns and relationships that govern complex relationships with .... adaptive management and complexity (Meissner et al., 2013; ... aged towards achieving South Africa's growth, development and ..... hydrological data and the reconciliation of systems) (DWA,. 2013) ..... submissions (i.e. the capitalist class).

  2. Annual and interannual variability of scatterometer ocean surface wind over the South China Sea

    DEFF Research Database (Denmark)

    Zhang, GS; Xu, Q.; Gong, Z.

    2014-01-01

    To investigate the annual and interannual variability of ocean surface wind over the South China Sea (SCS), the vector empirical orthogonal function (VEOF) method and the Hilbert-Huang transform (HHT) method were employed to analyze a set of combined satellite scatterometer wind data during...

  3. Aggregate surface areas quantified through laser measurements for South African asphalt mixtures

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2012-02-01

    Full Text Available thicknesses of five typical South African mixtures were calculated and compared with the film thicknesses calculated from the traditional Hveem method. Based on the laser scanning method, a new surface area factors were developed for coarse aggregates used...

  4. Spherules on shatter cone surfaces from the vredefort structure, South Africa.

    Science.gov (United States)

    Gay, N C

    1976-11-12

    Spherical particles of silicate composition occur on the surface of some shatter cones from the collar rocks around the Vredefort structure, South Africa. They are best developed on shatter cones from a shale horizon but are also found on more arenaceous rocks and banded ironstones. They have not been found on shatter cones from the purer quartzites.

  5. Arsenic, Fluoride and Vanadium in surface water (Chasicó Lake, Argentina

    Directory of Open Access Journals (Sweden)

    Maria laura ePuntoriero

    2014-06-01

    Full Text Available Chasicó Lake is the main water body in the southwest of the Chaco-Pampean plain. It shows some differences from the typical Pampean shallow lakes, such as high salinity and high arsenic and fluoride levels. The aim of this paper is to analyze the trace elements [arsenic (As, fluoride (F- and vanadium (V] present in Chasicó Lake. Surface and groundwater were sampled in dry and wet periods, during 2010 and 2011. Fluoride was determined with a selective electrode. As and V were determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES. Significant correlation in surface water was only found for As and F- (r=0.978, p<0.01. The As, F- and V concentration values were higher and more widely dispersed in surface water than in groundwater, as a consequence of evaporation. The fact that these elements do not correlate in surface water may also indicates that groundwater would not be the main source of origin of As, F- and V in surface water. The origin of these trace elements is from volcanic glass from Pampean loess. As, F- and V concentration were higher than in national and international guideline levels for the protection of aquatic biota. Hence, this issue is relevant since the silverside (Odontesthes bonariensis is the most important commercial species in Chasicó Lake. This fish is both consumed locally and exported to other South-American countries through commercial and sport fishing.

  6. Water-Recycling in South-East Queensland, Australia: What Do Men and Women Think?

    Science.gov (United States)

    Miller, Evonne; Buys, Laurie

    2008-01-01

    In January 2007, South-East Queensland became the first region in Australia to formally decide to introduce recycled water into the drinking supplies. Internationally, although water recycling occurs in the United States, United Kingdom, Singapore and Belgium, surprisingly little is known about public perceptions. This article explores gender…

  7. Failure of rural schemes in South Africa to provide potable water

    CSIR Research Space (South Africa)

    Mackintosh, G

    2003-05-01

    Full Text Available The impact of water-borne disease in South Africa is significant. An estimated 43,000 deaths per annum, including 20% of deaths in the 1-5 years age group, are directly attributable to diarrhoeal diseases. Drinking water quality provision in many...

  8. Contested water rights in post-apartheid South Africa: The struggle ...

    African Journals Online (AJOL)

    2010-03-25

    Mar 25, 2010 ... The National Water Act (1998) of South Africa provides strong tools to redress ..... The creation of homelands was a central element of this strategy. .... The cattle mainly drink from creeks and natural springs and ... in hydraulic infrastructure. ..... involved in the maintenance and future planning of the water.

  9. Access to adequate water in post-apartheid South African provinces ...

    African Journals Online (AJOL)

    2010-10-02

    Oct 2, 2010 ... agement of water resources in South Africa. ... supply services and that 50% were without adequate sanitation. (DWAF ... President Mbeki promised that 'within the next 5 years all ... This research has responded to debates about water service .... under the first category 'Piped Households' or 'Basic Access'.

  10. 1/33 SOME COMMENTS ON WATER RIGHTS IN SOUTH AFRICA N ...

    African Journals Online (AJOL)

    Administrator

    1 The human body needs to ingest water daily to continue functioning. ... 4 Constitution of the Republic of South Africa 200 of 1993, which came into effect on ...... water law as it had developed during the history of colonial expansion and sets.

  11. Quality of water from bedrock aquifers in the South Carolina Piedmont

    Science.gov (United States)

    Patterson, G.G.; Padgett, G.C.

    1984-01-01

    The geographic distributions of 12 common water-quality parameters of ground water from bedrock aquifers in the Piedmont physiographic province of South Carolina are presented in a series of maps. The maps are based on analyses by the South Carolina Department of Health and Environmental Control of water samples taken during the period 1972 to 1982 from 442 public and private wells developed in the Piedmont. In general, alkalinity, hardness, and concentrations of sodium, magnesium, and chloride were higher in the Carolina Slate Belt than they were in the other geologic belts of the Piedmont. (USGS)

  12. Atlas of water resources in the Black Hills area, South Dakota

    Science.gov (United States)

    Carter, Janet M.; Driscoll, Daniel G.; Williamson, Joyce E.; Lindquist, Van A.

    2002-01-01

    The Black Hills area is an important resource center that provides an economic base for western South Dakota through tourism, agriculture, the timber industry, and mineral resources. In addition, water originating from the area is used for municipal, industrial, agricultural, and recreational purposes throughout much of western South Dakota. The Black Hills area also is an important recharge area for aquifers in the northern Great Plains.Population growth, resource development, and periodic droughts have the potential to affect the quantity, quality, and availability of water within the Black Hills area. Growth has resulted in competing interests for available water supplies. The Black Hills Hydrology Study was initiated in 1990 to address these concerns. This long-term study is a cooperative effort between the U.S. Geological Survey (USGS), the South Dakota Department of Environment and Natural Resources, and the West Dakota Water Development District, which represents various local and county cooperators.

  13. CURRENT STATE AND PROBLEMS OF DEVELOPMENT OF THE WATER MANAGEMENT IN THE SOUTH OF RUSSIA

    Directory of Open Access Journals (Sweden)

    T. A. Shebzukhova

    2017-01-01

    Full Text Available Aim. The aim is to give a current and retrospective assessment of the state of water resources in the South of Russia and identify key problems in their use.Methods. Based on the analysis of dynamic and territorial series of data presented in government reports and the Central Statistical Database of the Federal State Statistics Service, we conducted diagnostic studies of the current and dynamic state of water resources use in the sub-federal units of the Russian Federation.Findings. The key problems in the functioning of the water sector in the southern regions are: natural water scarcity, large-scale transfers and artificial regulation of the river flows, significant loss of water during transport, large-scale discharge of contaminated sewage and poor quality of water. A significant interregional asymmetry in the water sector of the South of Russia is being tested.Conclusions. The key water-related contradiction in the South of the Russian Federation lies in the high water intensity of the meta-regional economy due to agricultural specialization, limited opportunities for the use of circulating systems, as well as significant losses of water during transportation in conditions of naturally caused scarcity and poor quality of potable waters

  14. Integrated Modeling of Groundwater and Surface Water Interactions in a Manmade Wetland

    Directory of Open Access Journals (Sweden)

    Guobiao Huang Gour-Tsyh Yeh

    2012-01-01

    Full Text Available A manmade pilot wetland in south Florida, the Everglades Nutrient Removal (ENR project, was modeled with a physics-based integrated approach using WASH123D (Yeh et al. 2006. Storm water is routed into the treatment wetland for phosphorus removal by plant and sediment uptake. It overlies a highly permeable surficial groundwater aquifer. Strong surface water and groundwater interactions are a key component of the hydrologic processes. The site has extensive field measurement and monitoring tools that provide point scale and distributed data on surface water levels, groundwater levels, and the physical range of hydraulic parameters and hydrologic fluxes. Previous hydrologic and hydrodynamic modeling studies have treated seepage losses empirically by some simple regression equations and, only surface water flows are modeled in detail. Several years of operational data are available and were used in model historical matching and validation. The validity of a diffusion wave approximation for two-dimensional overland flow (in the region with very flat topography was also tested. The uniqueness of this modeling study is notable for (1 the point scale and distributed comparison of model results with observed data; (2 model parameters based on available field test data; and (3 water flows in the study area include two-dimensional overland flow, hydraulic structures/levees, three-dimensional subsurface flow and one-dimensional canal flow and their interactions. This study demonstrates the need and the utility of a physics-based modeling approach for strong surface water and groundwater interactions.

  15. Mathematical Model of the Geothermal Water Resources in the South Hot Spring System in Chongqing

    Institute of Scientific and Technical Information of China (English)

    Liu Dongyan; Luo Yunju; Liu Xinrong

    2005-01-01

    The geothermal waters of south hot spring, small hot spring and Qiaokouba in Chongqing, are all part of the south hot spring geothermal water system. Exploitation has caused a decline in the water levels of the south and small hot springs, which have not flowed naturally for 15 years. Now, bores pump geothermal water to the springs. If the water level drops below the elevation of the rivers, river-water will replenish the geothermal water, destroying this resource. It is therefore an urgent task to model the geothermal water system, to enable sustainable development and continued use of the geothermal water in Qiaokouba. A numerical simulation of the geothermal water system was adopted and a quantitative study on the planning scheme was carried out. A mathematical model was set up to simulate the whole geothermal water system, based on data from the research sites. The model determined the maximum sustainable water yield in Qiaokouba and the two hot springs, and the south hot spring and small hot spring sustainable yields are 1 100 m3/d and 700 m3/d from 2006 to 2010, 1 300 m3/d and 1 000 m3/d from 2011 to 2015, and 1 500 m3/d and 1 200 m3/d from 2016 to 2036. The maximum exploitable yield is 3 300 m3/d from 2006 to 2036 in Qiaokouba. The model supplies a basis to adequately exploit and effectively protect the geothermal water resources, and to continue to develop the geothermal water as a tourist attraction in Chongqing.

  16. Layers of Porous Superhydrophobic Surfaces for Robust Water Repellency

    Science.gov (United States)

    Ahmadi, Farzad; Boreyko, Jonathan; Nature-Inspired Fluids; Interfaces Team

    2015-11-01

    In nature, birds exhibit multiple layers of superhydrophobic feathers that repel water. Inspired by bird feathers, we utilize porous superhydrophobic surfaces and compare the wetting and dewetting characteristics of a single surface to stacks of multiple surfaces. The superhydrophobic surfaces were submerged in water in a closed chamber. Pressurized gas was regulated to measure the critical pressure for the water to fully penetrate through the surfaces. In addition to using duck feathers, two-tier porous superhydrophobic surfaces were fabricated to serve as synthetic mimics with a controlled surface structure. The energy barrier for the wetting transition was modeled as a function of the number of layers and their orientations with respect to each other. Moreover, after partial impalement into a subset of the superhydrophobic layers, it was observed that a full dewetting transition was possible, which suggests that natural organisms can exploit their multiple layers to prevent irreversible wetting.

  17. Effects of winter irrigation and soil surface mulching during freezing-thawing period on soil water-heat-salt for cotton fields in south Xinjiang%冻融期灌水和覆盖对南疆棉田水热盐的影响

    Institute of Scientific and Technical Information of China (English)

    姚宝林; 李光永; 王峰

    2016-01-01

    Scarce water resources and soil salinity are important limiting factors for agricultural production and environmental melioration in extremely drought area and fragile ecological environment of Tarim Basin in southern Xinjiang. The under-film drip irrigation has gained universal applications as an efficient and economically viable irrigation method for increasing water use efficiency and reducing the adverse effects of cotton growth. But for winter and spring irrigation quotas are relatively high and cause groundwater level to rise, after freezing-thawing in winter, salinization occurs on soil surface and it is harmful to the growth and development of cotton seedlings. Soil surface mulching can effectively reduce soil water loss and soil salt accumulation in winter fallow periods, reduce winter and spring irrigation quota, and achieve the purpose of water saving and salinity controlling. To explore the freezing-thawing characteristics in drip irrigation cotton fields under different soil surface mulching and winter irrigation quotas, field experiments were carried out, which included 3 soil surface mulching methods: bare fields (cotton stubble and plastic film were removed before winter irrigation), high stubble fields (cotton stubble and plastic film remained in fields before winter irrigation), corn straw mulching fields (cotton stubble, plastic film remained in fields and mulched corn residue had the length of about 5-10 cm length and the thickness of 5 cm, 400 kg/hm2), and 2 winter irrigation quotas: winter irrigation 200 mm quota and no winter irrigation.Theexperiment was composed of 6 treatments: winter irrigation with bare land (WIB), winter irrigation with high cotton stubble (WICS), winter irrigation with corn straw mulching (WICM), no winter irrigation with bare land (NWIB), no winter irrigation with high cotton stubble (NWICS), and no winter irrigation with corn straw mulching (NWICM). The soil temperatures in 5, 10, 15, 20, 30, 40, 60, 80 and 100 cm

  18. Surface Spills at Unconventional Oil and Gas Sites: a Contaminant Transport Modeling Study for the South Platte Alluvial Aquifer

    Science.gov (United States)

    McCray, J. E.; Kanno, C.; McLaughlin, M.; Blotevogel, J.; Borch, T.

    2016-12-01

    Hydraulic fracturing has revolutionized the U.S.'s energy portfolio by making shale reservoirs productive and commercially viable. However, the public is concerned that the chemical constituents in hydraulic fracturing fluid, produced water, or natural gas itself could potentially impact groundwater. Here, we present fate and transport simulations of aqueous fluid surface spills. Surface spills are the most likely contamination pathway to occur during oil and gas production operations. We have three primary goals: 1) evaluate whether or not these spills pose risks to groundwater quality in the South Platte aquifer system, 2) develop a screening level methodology that could be applied at other sites and for various pollutants, and 3) demonstrate the potential importance of co-contaminant interactions using selected chemicals. We considered two types of fluid that can be accidentally released at oil and gas sites: produced water and hydraulic fracturing fluid. Benzene was taken to be a representative contaminant of interest for produced water. Glutaraldehyde, polyethylene glycol, and polyacrylamide were the chemical additives considered for spills of hydraulic fracturing fluid. We focused on the South Platte Alluvial Aquifer, which is located in the greater Denver metro area and overlaps a zone of high-density oil and gas development. Risk of groundwater pollution was based on predicted concentration at the groundwater table. In general, results showed groundwater contamination due to produced water and hydraulic fracturing fluid spills is low in most areas of the South Platte system for the contaminants and spill conditions investigated. Substantial risk may exist in certain areas where the groundwater table is shallow (less than 10 ft below ground surface) and when large spills and large post-spill storms occur. Co-chemical interactions are an important consideration in certain cases when modeling hydraulic fracturing fluid spills. By helping to identify locations

  19. Crab burrows as conduits for groundwater-surface water exchange in Bangladesh

    Science.gov (United States)

    Stahl, Mason O.; Tarek, M. H.; Yeo, Darren C. J.; Badruzzaman, A. B. M.; Harvey, Charles F.

    2014-12-01

    Groundwater recharge affects water budgets and groundwater quality on the deltas and floodplains of South and Southeast Asia. Rain and flooding rivers recharge groundwater during the monsoon; irrigated rice fields and surface water bodies recharge aquifers during the dry season. Groundwater throughout the region is severely contaminated by arsenic, and recent research suggests that quantifying and characterizing recharge is important to understand whether recharge flushes or mobilizes arsenic from aquifers. At a field site in Bangladesh, we found that burrows of terrestrial crabs short-circuit low-permeability surface sediments, providing the primary conduit for recharge. We combine field observations along with a model that couples isotope and water balances to quantify the effect of crab burrows on aquifer recharge. Given the wide distribution of burrowing crabs and the surficial geology, we suggest that crab burrows provide widespread conduits for groundwater recharge.

  20. Deep-water Earliest Oligocene Glacial Maximum (EOGM) in South Atlantic

    Institute of Scientific and Technical Information of China (English)

    LIU Zhifei; TUO Shouting; ZHAO Quanhong; CHENG Xinrong; HUANG Wei

    2004-01-01

    The most prominent cooling event of the Earth surface during Cenozoic in the long-term transition from a non-glaciated planet, or "green-house world", to a polar, glaciated planet, or "ice-house world", is the Earliest Oligocene Glacial Maximum (EOGM) above the Eocene/Oligocene boundary at about 33.7 Ma. Planktonic and benthic foraminiferal oxygen and carbon isotopes, carbonate content, and coarse fraction, along with high-resolution color reflectance and magnetic susceptibility records during 35-30 Ma, from deep-water Sites 1262 and 1265, Ocean Drilling Program (ODP) Leg 208 in South Atlantic, reveal the global cooling event occurring in both surface and deep oceans. The results show that the earliest Oligocene δ18O values during 33.5-33.1 Ma represent the magnitude of continental ice sheets on east Antarctica and indicate the large decrease in both surface and deep water temperatures of worldwide oceans. The δ13C records show the large excursion during the period of EOGM event and indicate some types of shift in global carbon reservoir, probably demonstrating the sudden increase in organic carbon burial rates and the changes in the distribution and timing of production. At the same time, lithologic composition, carbonate content, color reflectance, and coarse fraction brought about significant changes close to the Eocene/Oligocene boundary, reflecting the abrupt deepening in the carbonate compensation depth (CCD). Changes in carbonate content were revealed from the color reflectance identify periodicities associated with eccentricity of the Earth's orbit (100 and 400 ka), further indicating orbitally forced global climate variations in the Early Oligocene.

  1. Water quality of urban streams: the Allium cepa seeds/seedlings test as a tool for surface water monitoring.

    Science.gov (United States)

    Athanásio, Camila Gonçalves; Prá, Daniel; Rieger, Alexandre

    2014-01-01

    The present study investigates the genotoxic, mutagenic, and cytotoxic potential of surface waters in urban streams using Allium cepa and analyzes the applicability of this assay for environmental monitoring. Water samples were collected from three streams located in the urban area of a municipality in the south of Brazil. For each stream, two samples were collected, one upstream and one downstream of the pollution discharge site. Physicochemical evaluation indicated that all samples had various degrees of environmental impact, but substantial impact was seen for the downstream samples of the Preto and Pedras streams. All samples increased the frequency of chromosome aberrations (P Allium cepa seeds/seedlings were shown to be extremely sensitive in detecting the genotoxicity of environmental water samples and can be applied as the first tool for environmental health hazard identification and prediction.

  2. Groundwater, surface-water, and water-chemistry data from C-aquifer monitoring program, northeastern Arizona, 2005-11

    Science.gov (United States)

    Brown, Christopher R.; Macy, Jamie P.

    2012-01-01

    The C aquifer is a regionally extensive multiple-aquifer system supplying water for municipal, agricultural, and industrial use in northeastern Arizona, northwestern New Mexico, and southeastern Utah. An increase in groundwater withdrawals from the C aquifer coupled with ongoing drought conditions in the study area increase the potential for drawdown within the aquifer. A decrease in the water table and potentiometric surface of C aquifer is illustrated locally by the drying up of Obed Meadows, a natural peat deposit, and Hugo Meadows, a natural wetland, both south of Joseph City, Arizona. Continual increase in water use from the C aquifer, including a planned increase in pumpage by the City of Flagstaff, is justification for continued monitoring of the C-aquifer system in order to quantify physical and chemical responses to pumping stresses.

  3. Surface properties of a single perfluoroalkyl group on water surfaces studied by surface potential measurements.

    Science.gov (United States)

    Shimoaka, Takafumi; Tanaka, Yuki; Shioya, Nobutaka; Morita, Kohei; Sonoyama, Masashi; Amii, Hideki; Takagi, Toshiyuki; Kanamori, Toshiyuki; Hasegawa, Takeshi

    2016-12-01

    A discriminative study of a single perfluoroalkyl (Rf) group from a bulk material is recently recognized to be necessary toward the total understanding of Rf compounds based on a primary chemical structure. The single molecule and the bulk matter have an interrelationship via an intrinsic two-dimensional (2D) aggregation property of an Rf group, which is theorized by the stratified dipole-arrays (SDA) theory. Since an Rf group has dipole moments along many C-F bonds, a single Rf group would possess a hydrophilic-like character on the surface. To reveal the hydration character of a single Rf group, in the present study, surface potential (ΔV) measurements are performed for Langmuir monolayers of Rf-containing compounds. From a comparative study with a monolayer of a normal hydrocarbon compound, the hydration/dehydration dynamics of a lying Rf group on water has first been monitored by ΔV measurements, through which a single Rf group has been revealed to have a unique "dipole-interactive" character, which enables the Rf group interacted with the water 'surface.' In addition, the SDA theory proves to be useful to predict the 2D aggregation property across the phase transition temperature of 19°C by use of the ΔV measurements.

  4. Overview of water resource assessment in South Africa: Current ...

    African Journals Online (AJOL)

    is essential to planners and designers of water supply schemes and those ... Particular emphasis is given to the evolution of the computer as an ... we now call the historical firm yield. ..... In their article, Strategic planning for water resources in.

  5. The right of access to sufficient water in South Africa

    African Journals Online (AJOL)

    LAW

    interrelatedness of socio-economic rights, the right to water is regarded as implicitly ..... in Latin America and the Caribbean', conference organised by the Pan – American Health ..... databases and currently receive free basic water.120.

  6. OCCURRENCE OF ENTERIC VIRUSES IN SURFACE WATERS

    Science.gov (United States)

    Human enteric viruses cause a number of diseases when individuals are exposed to contaminated drinking & recreational waters. Vaccination against poliovirus has virtually eliminated poliomyelitis from the planet. Other members of enterovirus group cause numerous diseases. Hepatit...

  7. Interim Enhanced Surface Water Treatment Rule Documents

    Science.gov (United States)

    The IESWTR balances the need for treatment with potential increases in disinfection by -products. The materials found on this page are intended to assist public water systems and state in the implementation of the IESWTR.

  8. SurfaceWater Source Protection Areas (SPAs)

    Data.gov (United States)

    Vermont Center for Geographic Information — Source Protection Area (SPA) boundaries have been located on RF 24000 & RF 25000 scale USGS topographic maps by Water Supply Division (DEC) and VT Dept of Health...

  9. SURFACE WATER QUALITY IN ADDIS ABABA, ETHIOPIA

    African Journals Online (AJOL)

    environmental pollution derived from domestic and industrial activities. Due to the inadequacy of controlled waste management strategies and waste treatment plants ... Oxygen Demand (COD), Biological Oxygen Demand (BOD) and Dissolved ... appropriate waste water purifying plants. ..... University of Turku, Finland. 2.

  10. Bioinspired aquatic microrobot capable of walking on water surface like a water strider.

    Science.gov (United States)

    Zhang, Xinbin; Zhao, Jie; Zhu, Qing; Chen, Ning; Zhang, Mingwen; Pan, Qinmin

    2011-07-01

    Walking on the water surface is a dream of humans, but it is exactly the way of life for some aquatic insects. In this study, a bionic aquatic microrobot capable of walking on the water surface like a water strider was reported. The novel water strider-like robot consisted of ten superhydrophobic supporting legs, two miniature dc motors, and two actuating legs. The microrobot could not only stand effortlessly but also walk and turn freely on the water surface, exhibiting an interesting motion characteristic. A numerical model describing the interface between the partially submerged leg and the air-water surface was established to fully understand the mechanism for the large supporting force of the leg. It was revealed that the radius and water contact angle of the legs significantly affect the supporting force. Because of its high speed, agility, low cost, and easy fabrication, this microrobot might have a potential application in water quality surveillance, water pollution monitoring, and so on.

  11. Sensitivity of simulated South America Climate to the Land Surface Schemes in RegCM4

    Science.gov (United States)

    Llopart, Marta; da Rocha, Rosmeri; Reboita, Michelle; Cuadra, Santiago

    2017-04-01

    This work evaluates the impact of two land surface parameterizations on the simulated climate and its variability over South America (SA). Two numerical experiments using RegCM4 coupled with Biosphere-Atmosphere Transfer Scheme (RegBATS) and Community Land Model version 3.5 (RegCLM) land surface schemes are compared. For the period 1979-2008, RegCM4 simulations used 50 km horizontal grid spacing and the ERA-Interim reanalysis as initial and boundary conditions. For the period studied, both simulations represent the main observed spatial patterns of rainfall, air temperature and low level circulation over SA. However, concerning the precipitation intensity, RegCLM values are closer to the observations than RegBATS (it is in general, wetter) over most of SA. RegCLM also provides smaller biases for air temperature. Over the Amazon basin, the amplitudes of the annual cycles of the soil moisture, evapotranspiration and sensible heat flux are higher in RegBATS than in RegCLM. This indicates that RegBATS provides large amounts of water vapor to the atmosphere and has more available energy to increase the boundary layer and make it reach the level of free convection (higher sensible heat flux values) resulting in higher precipitation rates and a large wet bias. RegCLM is closer to the observations than RegBATS, presenting smaller wet and warm biases over the Amazon basin. On an interannual scale, the magnitudes of the anomalies of the precipitation and air temperature simulated by RegCLM are closer to the observations. In general, RegBATS simulates higher magnitude for the interannual variability signal.

  12. Unique water-water coordination tailored by a metal surface

    DEFF Research Database (Denmark)

    Schiros, T.; Andersson, Klas Jerker; MacNaughton, J.;

    2013-01-01

    At low coverage of water on Cu(110), substrate-mediated electrostatics lead to zigzagging chains along [001] as observed with STM [T. Yamada, S. Tamamori, H. Okuyama, and T. Aruga, “Anisotropic water chain growth on Cu(110) observed with scanning tunneling microscopy” Phys. Rev. Lett. 96, 036105...... (2006)]. Using x-ray absorption spectroscopy we find an anomalous low-energy resonance at ~533.1 eV which, based on density functional theory spectrum simulations, we assign to an unexpected configuration of water units whose uncoordinated O-H bonds directly face those of their neighbors...

  13. Measurements of water surface snow lines in classical protoplanetary disks

    CERN Document Server

    Blevins, Sandra M; Banzatti, Andrea; Zhang, Ke; Najita, Joan R; Carr, John S; Salyk, Colette; Blake, Geoffrey A

    2015-01-01

    We present deep Herschel-PACS spectroscopy of far-infrared water lines from a sample of four protoplanetary disks around solar-mass stars, selected to have strong water emission at mid-infrared wavelengths. By combining the new Herschel spectra with archival Spitzer-IRS spectroscopy, we retrieve a parameterized radial surface water vapor distribution from 0.1-100 AU using two-dimensional dust and line radiative transfer modeling. The surface water distribution is modeled with a step model comprising of a constant inner and outer relative water abundance and a critical radius at which the surface water abundance is allowed to change. We find that the four disks have critical radii of $\\sim 3-11$ AU, at which the surface water abundance decreases by at least 5 orders of magnitude. The measured values for the critical radius are consistently smaller than the location of the surface snow line, as predicted by the observed spectral energy distribution. This suggests that the sharp drop-off of the surface water abu...

  14. Water Distribution in the Public Interest and the Human Right to Water: Swiss, South African and International Law Compared

    Directory of Open Access Journals (Sweden)

    Vanessa Rüegger

    2014-06-01

    Full Text Available The legal norms governing the distribution of water are integral to how access to water is determined. This paper analyses the idea that water should be used in the interest of the public from a legal point of view. Taking Swiss and South African law as examples it examines what the notion of 'public interest' actually means. A close look at the notion of 'water distribution in the public interest' reveals important insights: water distribution in the public interest balances a variety of different economic, ecological and social interests. In this process the human right to water is attributed the role as protective shield. Hence its effective implementation is crucial in order to safeguard water for basic human needs. After analysing how Swiss and South African water regimes are currently structured and the role of the public interest clause therein, the paper examines whether the human right to water as conceived in Swiss, South African and international law effectively ensures protection of domestic water users. The paper concludes that this is the case under some, but not all circumstances. Especially the interests of those users whose access to water is not yet sufficient do not always receive adequate legal protection by the respective legal orders. The paper concludes by stressing the necessity to evolve the concept of the human right to water to reach comprehensive protection of basic human needs. Consciousness of the social risks associated with using the human right to water as general placeholder for basic human needs despite its shortcomings will hopefully encourage efforts to establish substantive legal protection.

  15. Late Quaternary upper-water column structure in upwelling areas of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on a quantitative analysis of planktonic foraminifera in two gravity cores (17928 and 17954), the history of the upper-water structure of the eastern and western slopes of the South China Sea (SCS) over the last 220 Ka was reconstructed using the transfer function technique. Our results show that lower sea surface temperature (SST) and shallower depth of thermocline (DOT) exist at Core 17928, off Luzon, in the glacial periods; on the contrary, the same situation turned up in the interglacial at Core 17954, off Vietnam. These changes of the upper-water column structure in the two areas are induced by coastal upwelling, which in turn is driven by monsoons, namely, winter monsoon leads to upwelling at the eastern slope, and summer monsoon gives birth to upwelling on the western slope. Moreover, the intensity of upwellings is also closely related to the evolution of the East Asian monsoon. Therefore, we assume that the changes of the upwelling in the two sites indicate strengthenning of winter and su mmer monsoon during the glacial and interglacial periods, respectively.

  16. Prevalence of Legionella spp. in water systems of hospitals and hotels in South Western Greece.

    Science.gov (United States)

    Fragou, K; Kokkinos, P; Gogos, C; Alamanos, Y; Vantarakis, A

    2012-01-01

    The aim of the present study was to determine the prevalence of Legionella spp. in water systems of hospitals and hotels located in South Western Greece, to study the molecular epidemiology of the isolated strains and their possible association with bacterial contamination (total count and Pseudomonas aeruginosa), the water pH, and temperature. A prevalence survey for Legionella spp. by culturing techniques in water distribution systems of eight hospitals and nine hotels occurred in South Western Greece. Water sampling and microbiological analysis were carried out following the ISO methods. Legionella pneumophila was detected in 33% and 36% of the distribution systems of hospitals and hotels, respectively. Our survey results suggest a frequent prevalence of elevated concentrations of Legionella spp. in water systems of hospitals and hotels. Our investigation has confirmed the need to regularly monitor the microbiological condition of water systems in hospitals and hotels.

  17. Deep water dissolution in Marine Isotope Stage 3 from the northern South China Sea

    Science.gov (United States)

    Huang, B.

    2015-12-01

    The production, transport, deposition, and dissolution of carbonate profoundly implicate the global carbon cycle affect the inventory and distribution of dissolved organic carbon (DIC) and alkalinity (ALK), which drive atmospheric CO2 change on glacial-interglacial timescale. the process may provide significant clues for improved understanding of the mechanisms that control the global climate system. In this study, we calculate and analyze the foraminiferal dissolution index (FDX) and the fragmentation ratios of planktonic foraminifera over 60-25 ka based on samples from 17924 and ODP 1144 in the northeastern South China Sea (SCS) to reconstruct the deep water carbonate dissolution during Marine Isotope Stage 3 (MIS 3). Result shows that the dissolution of carbonate increases gradually at 17924 but keeps stable at ODP 1144. The changes of FDX coincidence with that of fragmentation ratios at 17924 and ODP 1144 suggest both indexes can be used as reliable dissolving proxies of planktonic foraminifera. Comparing FDX and fragmentation ratios at both sites, we find the FDX and fragmentation ratios at 17924 are higher than those at 1144, indicating that carbonate dissolution is intenser in 17924 core during MIS 3. The increasing total percentage of both N. dutertrei and G. bulloides during MIS 3 reveals the rising primary productivity that may lead to deep water [CO32-] decrease. The slow down of thermohaline circulation may increase deep water residence time and accelerate carbonate dissolution. In addition, the covering of ice caps, iron supply and increased surface-water stratification also contribute to atmosphere CO2 depletion and [CO32-] decrease in deep water. In the meanwhile, regression result from colder temperature increases the input of ALK and DIC to the deep ocean and deepens the carbonate saturation depth, which makes the deep water [CO32-] rise. In ODP Site 1144, the decrease in [CO32-] caused by more CO2 restored in deep water is equal to the increase in

  18. Paradigms and Theories Influencing Policies in the South African and International Water Sectors: PULSE³, A Framework for Policy Analysis

    CSIR Research Space (South Africa)

    Meissner, Richard

    2017-01-01

    Full Text Available  Meissner Paradigms and Theories Influencing Policies in the South African and International Water Sectors PULSE3, A Framework for Policy Analysis Paradigms and Theories Influencing Policies in the South African and International Water Sectors rmeissner...@csir.co.za Richard Meissner Paradigms and Theories Influencing Policies in the South African and International Water Sectors PULSE3, A Framework for Policy Analysis 123 rmeissner@csir.co.za Richard Meissner Council for Scientific and Industrial Research (CSIR...

  19. Stability of Water Ice Beneath Porous Dust Layers of the Martian South Polar Terrain

    Science.gov (United States)

    Keller, H. U.; Skorov, Yu. V.; Markiewicz, W. J.; Basilevsky, A. T.

    2000-08-01

    The analysis of the Viking Infrared Thermal Mapper (IRTM) data show that the surface layers of the Mars south polar layered deposits have very low thermal inertia between 75 and 125 J/(sq m)(s-1/2)(K-1). This is consistent with the assumption that the surface is covered by a porous layer of fine dust. Paige and Keegan determined a slightly higher value based on a thermal model similar to that of Kieffer et al. In this model the heat transfer equation is used to estimate the thickness of the layer that protects the ground ice from seasonal and diurnal temperature variations. The physical properties of the layer are unimportant as long as it has a low thermal inertia and conductivity and keeps the temperature at the ice boundary low enough to prevent sublimation. A thickness between 20 and 4 cm was estimated. This result can be considered to be an upper limit. We assume the surface to be covered by a porous dust layer and consider the gas diffusion through it, from the ground ice and from the atmosphere. Then the depth of the layer is determined by the mass flux balance of subliming and condensing water and not by the temperature condition. The dust particles in the atmosphere are of the order 1 gm. On the surface we can expect larger grains (up to sand size). Therefore assuming an average pore size of 10 gm, a volume porosity of 0.5, a heat capacity of 1300 J/(kg-1)(K-1) leads to a thermal inertia of approx. 80 J/(sq m)(s-1/2)(K-1). With these parameters a dust layer of only 5 mm thickness is found to establish the flux balance at the ice-dust interface during spring season in the southern hemisphere at high latitudes (where Mars Polar Lander arrived). The diurnal temperature variation at the ice-dust surface is shown. The maximum of 205 K well exceeds the sublimation temperature of water ice at 198 K under the atmospheric conditions. The corresponding vapour flux during the last day is shown together with the flux condensing from the atmosphere. The calculations

  20. Survival of Phytophthora infestans in Surface Water.

    Science.gov (United States)

    Porter, Lyndon D; Johnson, Dennis A

    2004-04-01

    ABSTRACT Coverless petri dishes with water suspensions of sporangia and zoospores of Phytophthora infestans were embedded in sandy soil in eastern Washington in July and October 2001 and July 2002 to quantify longevity of spores in water under natural conditions. Effects of solar radiation intensity, presence of soil in petri dishes (15 g per dish), and a 2-h chill period on survival of isolates of clonal lineages US-8 and US-11 were investigated. Spores in water suspensions survived 0 to 16 days under nonshaded conditions and 2 to 20 days under shaded conditions. Mean spore survival significantly increased from 1.7 to 5.8 days when soil was added to the water. Maximum survival time of spores in water without soil exposed to direct sunlight was 2 to 3 days in July and 6 to 8 days in October. Mean duration of survival did not differ significantly between chilled and nonchilled sporangia, but significantly fewer chilled spores survived for extended periods than that of nonchilled spores. Spores of US-11 and US-8 isolates did not differ in mean duration of survival, but significantly greater numbers of sporangia of US-8 survived than did sporangia of US-11 in one of three trials.

  1. Georgia's Surface-Water Resources and Streamflow Monitoring Network, 2008

    Science.gov (United States)

    ,

    2008-01-01

    Surface water provides 5 billion gallons per day, or 78 percent, of the total freshwater used (including thermoelectric) in Georgia (Fanning, 2003). Climate, geology, and landforms control the natural distribution of Georgia's water resources. Georgia is a 'headwaters' State, with most of the rivers beginning in northern Georgia and increasing in size downstream (see map at right for major watersheds). Surface water is the primary source of water in the northern one-half of the State, including the Atlanta metropolitan area, where limited ground-water resources are difficult to obtain. In Georgia, periodic droughts exacerbate competition for surface-water supplies. Many areas of Georgia also face a threat of flooding because of spring frontal thunderstorms and the potential for hurricanes from both the Atlantic Ocean and Gulf of Mexico. As the population of Georgia increases, these flood risks will increase with development in flood-risk zones, particularly in the coastal region.

  2. Surface complexation at calcium mineral-water interfaces

    OpenAIRE

    Wu, Liuming

    1994-01-01

    Surface reactions occurring at solid-water interfaces in calcium mineral-ligands systems have been studied. Both hydrous apatite and fluorite surfaces show clear amphoteric properties. An ion exchange process between lattice ions of F- on fluorite and OH- ions in bulk solution is discovered. The surface adsorption of Alizarin Red S and sodium oleate are determined. Surface chemical reaction models are established based on acidbase potentiometric titrations, solubility, adsorption and zeta-pot...

  3. A molecular dynamics study on surface properties of supercooled water

    Institute of Scientific and Technical Information of China (English)

    L(U) Yongjun; WEI Bingbo

    2006-01-01

    Molecular dynamics simulations were performed to study the surface properties of water in a temperature range from 228 to 293 K by using the extended simple point charge (SPC/E) and four-site TIP4P potentials. The calculated surface tension increases with the decrease of temperature, and moreover the slopes of the surface tension-temperature curves show a weak rise below 273 K, whereas no obvious anomalies appear near 228 K, which accords with the previous experiments. Compared with the measured values, the SPC/E potential shows a good agreement, and the TIP4P potential scription of the surface structure of supercooled water for the SPC/E. When simulating the orientational distributions of water molecules near the surface, the SPC/E potential produces higher ordering and larger surface potentials than the TIP4P potential.

  4. Tractor beam on the water surface

    CERN Document Server

    Punzmann, Horst; Xia, Hua; Falkovich, Gregory; Shats, Michael

    2014-01-01

    Can one send a wave to bring an object from a distance? The general idea is inspired by the recent success in moving micro particles using light and the development of a tractor beam concept. For fluid surfaces, however, the only known paradigm is the Stokes drift model, where linear planar waves push particles in the direction of the wave propagation. Here we show how to fetch a macroscopic floater from a large distance by sending a surface wave towards it. We develop a new method of remote manipulation of floaters by forming inward and outward surface jets, stationary vortices, and other complex surface flows using nonlinear waves generated by a vertically oscillating plunger. The flows can be engineered by changing the geometry and the power of a wave maker, and the flow dissipation. The new method is robust and works both for long gravity and for short capillary waves. We use a novel method of visualising 3D particle trajectories on the surface. This letter introduces a new conceptual framework for unders...

  5. Experimental Observation of Dark Solitons on Water Surface

    Science.gov (United States)

    2016-06-13

    vertical walls are made of transparent sections of glass supported by the metal frame. The water level of the free surface is measured with seven resistive...Experimental observation of dark solitons on water surface A. Chabchoub1,∗, O. Kimmoun2, H. Branger3, N. Hoffmann1, D. Proment4, M. Onorato4,5, and N...observation of dark solitons on the water surface. It takes the form of an amplitude drop of the carrier wave which does not change shape in propagation

  6. Drainage-water travel times as a key factor for surface water contamination

    OpenAIRE

    Groenendijk, P.; Eertwegh, van den, A.J.M.

    2004-01-01

    The importance of the unsaturated zone as an inextricable part of the hydrologic cycle has long been recognized. The root zone and the unsaturated sub-surface domain are chemically and biologically the most active zones. The interrelationships between soil, subsoil and surface waters make it unrealistic to treat the saturated and unsaturated zones and the discharge to surface waters separately. Point models describe vertical water flow in the saturated zone and possibly lateral flow by defini...

  7. Northern South China Sea Surface Circulation and its Variability Derived by Combining Satellite Altimetry and Surface Drifter Data

    Directory of Open Access Journals (Sweden)

    N. Peter Benny

    2015-01-01

    Full Text Available The present study analyses the mean and seasonal mesoscale surface circulation of the Northern South China Sea (NSCS and determines the influence of El Niño/SouthernNiño/Southern Oscillation (ENSO. High resolution Eulerian velocity field is derived by combining the available satellite tracked surface drifter data with satellite altimetry during 1993 - 2012. The wind driven current is computed employing the weekly ocean surface mean wind fields derived from the scatterometers on board ERS 1/2, QuikSCAT and ASCAT. The derived mean velocity field exhibits strong boundary currents and broad zonal flow across NSCS. The anomalous field is quite strong in the southern part and the Seasonal circulation clearly depicts the monsoonal forcing. Eddy Kinetic Energy (EKE distribution and its spatial and temporal structures are determined employing Empirical Orthogonal Function (EOF analysis. The ENSO influence on NSCS surface circulation has been analyzed using monthly absolute geostrophic velocity fields during 1996 - 1999.

  8. ENSO related SST anomalies and relation with surface heat fluxes over south Pacific and Atlantic

    Science.gov (United States)

    Chatterjee, S.; Nuncio, M.; Satheesan, K.

    2017-07-01

    The role of surface heat fluxes in Southern Pacific and Atlantic Ocean SST anomalies associated with El Nino Southern Oscillation (ENSO) is studied using observation and ocean reanalysis products. A prominent dipole structure in SST anomaly is found with a positive (negative) anomaly center over south Pacific (65S-45S, 120W-70W) and negative (positive) one over south Atlantic (50S-30S, 30W-0E) during austral summer (DJF) of El Nino (LaNina). During late austral spring-early summer (OND) of El Nino (LaNina), anomalous northerly (southerly) meridional moisture transport and a positive (negative) sea level pressure anomaly induces a suppressed (enhanced) latent heat flux from the ocean surface over south Pacific. This in turn results in a shallower than normal mixed layer depth which further helps in development of the SST anomaly. Mixed layer thins further due to anomalous shortwave radiation during summer and a well developed SST anomaly evolves. The south Atlantic pole exhibits exactly opposite characteristics at the same time. The contribution from the surface heat fluxes to mixed layer temperature change is found to be dominant over the advective processes over both the basins. Net surface heat fluxes anomaly is also found to be maximum during late austral spring-early summer period, with latent heat flux having a major contribution to it. The anomalous latent heat fluxes between atmosphere and ocean surface play important role in the growth of observed summertime SST anomaly. Sea-surface height also shows similar out-of-phase signatures over the two basins and are well correlated with the ENSO related SST anomalies. It is also observed that the magnitude of ENSO related anomalies over the southern ocean are weaker in LaNina years than in El Nino years, suggesting an intensified tropics-high latitude tele-connection during warm phases of ENSO.

  9. Quality of surface water in Missouri, water year 2012

    Science.gov (United States)

    Barr, Miya N.

    2014-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2012 water year (October 1, 2011, through September 30, 2012), data were collected at 81 stations—73 Ambient Water-Quality Monitoring Network stations, 6 alternate Ambient Water-Quality Monitoring Network stations, and 2 U.S. Geological Survey National Stream Quality Accounting Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 78 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  10. Quality of surface water in Missouri, water year 2013

    Science.gov (United States)

    Barr, Miya N.; Schneider, Rachel E.

    2014-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2013 water year (October 1, 2012, through September 30, 2013), data were collected at 79 stations—73 Ambient Water-Quality Monitoring Network stations, 4 alternate Ambient Water-Quality Monitoring Network stations, and 2 U.S. Geological Survey National Stream Quality Accounting Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, Escherichia coli bacteria, fecal coliform bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 76 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  11. ASSESSMENT OF SURFACE WATER QUALITY IN AN ARSENIC CONTAMINATED VILLAGE

    Directory of Open Access Journals (Sweden)

    Kumud C. Saikia

    2012-01-01

    Full Text Available Arsenic contamination of ground water has occurred in various parts of the world, becoming a menace in the Ganga-Meghna-Brahmaputra basin (West Bengal and Assam in India and Bangladesh. Recently arsenic has been detected in Cachar and Karimganj districts of barak valley, Assam, bordering Bangladesh. In this area coli form contamination comprises the major constraint towards utilization of its otherwise ample surface water resources. The local water management exploited ground water sources using a centralized piped water delivery scheme without taking into account the geologically arsenic-prone nature of the sediments and aquifers in this area. Thus surface water was the suggestive alternative for drinking water in this area. The present study investigated surface water quality and availability in a village of Karimganj district, Assam, India contaminated with arsenic for identifying the potential problems of surface water quality maintenance so that with effective management safe drinking water could be provided. The study revealed that the area was rich in freshwater ecosystems which had all physico-chemical variables such as water temperature, pH, DO, total alkalinity, free CO2, heavy metals like lead, chromium and cadmium within WHO standards. In contrast, coli form bacteria count was found far beyond permissible limit in all the sources. Around 60% people of the village preferred ground water for drinking and only 6% were aware of arsenic related problems. The problem of bacterial contamination could be controlled by implementing some ameliorative measures so that people can safely use surface water. Inhabitants of the two districts should be given proper education regarding arsenic contamination and associated health risk. Effluents should be treated to acceptable levels and standards before discharging them into natural streams.

  12. Electron bombardment of water adsorbed on Zr(0001) surfaces

    CERN Document Server

    Ankrah, S; Ramsier, R D

    2003-01-01

    A study of the effects of electron bombardment on water adsorbed on Zr(0001) is reported. Zirconium surfaces are dosed with isotopic water mixtures at 160 K followed by electron bombardment (485 eV). The system is then probed by low energy electron diffraction, temperature programmed desorption (TPD) and Auger electron spectroscopy (AES). No evidence is found that would indicate preferential mixing of hydrogen from the bulk with isotopic water dissociation products during TPD. However, electron bombardment results in the sharpening of a hydrogen/deuterium desorption peak near 320 K and the production of water near 730 K at low water exposures. In addition, although water does not oxidize Zr(0001) thermally, electron bombardment of adsorbed water induces a shift of about 2 eV in the Zr AES features indicating that the surface is partially oxidized by electron bombardment.

  13. Quality of surface water in Missouri, water year 2014

    Science.gov (United States)

    Barr, Miya N.

    2015-12-18

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2014 water year (October 1, 2013, through September 30, 2014), data were collected at 74 stations—72 Ambient Water-Quality Monitoring Network stations and 2 U.S. Geological Survey National Stream Quality Assessment Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, Escherichia coli bacteria, fecal coliform bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 71 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  14. Quality of surface water in Missouri, water year 2010

    Science.gov (United States)

    Barr, Miya N.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designs and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2010 water year (October 1, 2009 through September 30, 2010), data were collected at 75 stations-72 Ambient Water-Quality Monitoring Network stations, 2 U.S. Geological Survey National Stream Quality Accounting Network stations, and 1 spring sampled in cooperation with the U.S. Forest Service. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 72 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  15. Quality of surface water in Missouri, water year 2009

    Science.gov (United States)

    Barr, Miya N.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designs and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2009 water year (October 1, 2008, through September 30, 2009), data were collected at 75 stations-69 Ambient Water-Quality Monitoring Network stations, 2 U.S. Geological Survey National Stream Quality Accounting Network stations, 1 spring sampled in cooperation with the U.S. Forest Service, and 3 stations sampled in cooperation with the Elk River Watershed Improvement Association. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 72 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and seven-day low flow is presented.

  16. Quality of surface water in Missouri, water year 2011

    Science.gov (United States)

    Barr, Miya N.

    2012-01-01

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams throughout Missouri known as the Ambient Water-Quality Monitoring Network. During the 2011 water year (October 1, 2010, through September 30, 2011), data were collected at 75 stations—72 Ambient Water-Quality Monitoring Network stations, 2 U.S. Geological Survey National Stream Quality Accounting Network stations, and 1 spring sampled in cooperation with the U.S. Forest Service. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, fecal coliform bacteria, Escherichia coli bacteria, dissolved nitrate plus nitrite, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 72 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak discharges, monthly mean discharges, and 7-day low flow is presented.

  17. Quality of surface water in Missouri, water year 2015

    Science.gov (United States)

    Barr, Miya N.; Heimann, David C.

    2016-11-14

    The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, designed and operates a series of monitoring stations on streams and springs throughout Missouri known as the Ambient Water-Quality Monitoring Network. During water year 2015 (October 1, 2014, through September 30, 2015), data were collected at 74 stations—72 Ambient Water-Quality Monitoring Network stations and 2 U.S. Geological Survey National Stream Quality Assessment Network stations. Dissolved oxygen, specific conductance, water temperature, suspended solids, suspended sediment, Escherichia coli bacteria, fecal coliform bacteria, dissolved nitrate plus nitrite as nitrogen, total phosphorus, dissolved and total recoverable lead and zinc, and select pesticide compound summaries are presented for 71 of these stations. The stations primarily have been classified into groups corresponding to the physiography of the State, primary land use, or unique station types. In addition, a summary of hydrologic conditions in the State including peak streamflows, monthly mean streamflows, and 7-day low flows is presented.

  18. National water services asset management strategy for South Africa

    CSIR Research Space (South Africa)

    Wall, K

    2007-05-01

    Full Text Available in developing countries" ("An IWA-supported conference under the auspices of the Specialist Group for Developing Countries") Session on "Management and policy issues" Theme "Asset management". Kuala Lumpur, Malaysia, May 2007 Abstract: South African... stream_source_info Wall_2007.pdf.txt stream_content_type text/plain stream_size 17927 Content-Encoding UTF-8 stream_name Wall_2007.pdf.txt Content-Type text/plain; charset=UTF-8 1 0612 Wall IWA Inframan Malaysia 2nd...

  19. Role of water in polymer surface modification using organosilanes

    Science.gov (United States)

    Thallapalle, Pradeep Kumar; Zhang Newby, Bi-Min

    2002-03-01

    In general, polymers exhibit excellent bulk properties but may not possess specific surface properties for successful applications in biomaterials and nanotechnology. Surface modification of polymers with the self-assembled monolayers (SAMs) of organosilanes - ‘Silanization’ - is an attractive approach to alter surface properties without altering the polymer’s desired bulk properties. However, a pretreatment such as exposure to UV/O or plasma is normally required to generate active surface groups prior to silanization. These pretreatments cause undesirable surface changes such as severe surface roughening and excessive surface damage. Recent studies in silanization suggest that the presence of water or OH groups on the surface is essential to form SAMs. In this study we investigated the importance of surface water layer and OH groups in the formation of SAMs for a variety of polymers. The pre and post-modified polymers were examined using fourier transform infrared spectrometry, scanning probe microscopy and contact angle measurements. The results show that organosilanes can be grafted to a polymer surface as long as a water layer can be physisorbed to the surface or the polymer itself contains OH groups. However the monolayers formed are less organized compared to those formed on silicon wafers due to the amorphous nature of the polymers.

  20. Perceptions of Water Pricing during a Drought: A Case Study from South Australia

    Directory of Open Access Journals (Sweden)

    John Martin

    2013-02-01

    Full Text Available This paper examines the perceptions of urban and regional water consumers in three areas of South Australia on the fairness of the water pricing system, the impact of increases in water pricing on households and pricing as a driver of water conservation. The study was conducted in 2009 during a time of severe drought and mandatory water restrictions. The results did not show a general aversion to all aspects of price increases but rather different sectors of the population were particularly resistant to different, specific aspects of water pricing. A state-wide water pricing policy in South Australia means that all consumers pay the same rate per volume of water consumed regardless of their location; yet in the regional study area, where it costs more for the service provider to supply the water, the respondents had stronger feelings that the price of water should be higher in places where it costs more to supply it. Generally, low income earners were less in favor of a block pricing system than higher income earners. The latter findings indicate a common lack of awareness around various aspects of water pricing. Some implications of the findings for water managers are outlined.

  1. Methodology to produce a water and energy stream map (WESM in the South African manufacturing industry

    Directory of Open Access Journals (Sweden)

    Davies, Edward

    2016-11-01

    Full Text Available The increasing demand for water and energy in South Africa, and the capacity constraints and restrictions of both resources, have led to a rapid increase in their cost. The manufacturing industry remains South Africa’s third-largest consumer of water and second- largest consumer of national energy. The improvement of water and energy efficiency is becoming an increasingly important theme for both organisational success and national economic sustainability. This paper presents the ‘lean based water and energy stream mapping framework’ developed for the manufacturing industry, with the specific objective of decreasing its water and energy intensity. As with the traditional value stream mapping tool, the water and energy stream mapping focuses on eliminating water- and energy-specific wastes within a process. Water and energy waste categories that will be used in conjunction with the framework will also be discussed. The key objective of this paper is to detail the process of creating the water and energy stream mapping, and the statistical forecasting methodology used to develop the baseline water and energy demand data. The outcome of the implementation of the framework is the future state water and energy stream mapping, which is effectively a blueprint for increased water and energy efficiency within a studied process.

  2. Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports

    DEFF Research Database (Denmark)

    Daryabor, Farshid

    2016-01-01

    of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic......A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re......-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast...

  3. SWFSC FED Mid Water Trawl Juvenile Rockfish Survey, Surface Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC FED Mid Water Trawl Juvenile Rockfish Survey: Station Information and Surface Data. Surveys have been conducted along the central California coast in May/June...

  4. Second Inflection Point of the Surface Tension of Water

    Science.gov (United States)

    Kalova, Jana; Mares, Radim

    2012-06-01

    The theme of a second inflection point of the temperature dependence of the surface tension of water remains a subject of controversy. Using data above 273 K, it is difficult to get a proof of existence of the second inflection point, because of experimental uncertainties. Data for the surface tension of supercooled water and results of a molecular dynamics study were included into the exploration of existence of an inflection point. A new term was included into the IAPWS equation to describe the surface tension in the supercooled water region. The new equation describes the surface tension values of ordinary water between 228 K and 647 K and leads to the inflection point value at a temperature of about 1.5 °C.

  5. Shallow Water Propagation and Surface Reverberation Modeling

    Science.gov (United States)

    2012-09-30

    compare the results with experiment. This work will be used to help interpret field data of bistatic scattering from sea ice cover and calibrate...approximate analytical and numerical acoustic models used to compute bistatic scattering. The clouds of bubbles entrained at the sea surface by breaking...ABSTRACT SAR 18. NUMBER OF PAGES 7 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified

  6. Tracer injection techniques in flowing surface water

    Science.gov (United States)

    Wörman, A.

    2009-04-01

    Residence time distributions for flowing water and reactive matter are commonly used integrated properties of the transport process for determining technical issues of water resource management and in eco-hydrological science. Two general issues for tracer techniques are that the concentration-vs-time relation following a tracer injection (the breakthrough curve) gives unique transport information in different parts of the curve and separation of hydromechanical and reactive mechanisms often require simultaneous tracer injections. This presentation discusses evaluation methods for simultaneous tracer injections based on examples of tracer experiments in small rivers, streams and wetlands. Tritiated water is used as a practically inert substance to reflect the actual hydrodynamics, but other involved tracers are Cr(III)-51, P-32 and N-15. Hydromechanical, in-stream dispersion is reflected as a symmetrical spreading of the spatial concentration distribution. This requires that the transport distance over water depth is larger than about five times the flow Peclet number. Transversal retention of both inert and reactive solutes is reflected in terms of the tail of the breakthrough curve. Especially, reactive solutes can have a substantial magnification of the tailing behaviour depending on reaction rates or partitioning coefficients. To accurately discriminate between the effects of reactions and hydromechanical mixing its is relevant to use simultaneous injections of inert and reactive tracers with a sequential or integrated evaluation procedure. As an example, the slope of the P-32 tailing is consistently smaller than that of a simultaneous tritium injection in Ekeby wetland, Eskilstuna. The same applies to N-15 injected in the same experiment, but nitrogen is affected also by a systematic loss due to denitrification. Uptake in stream-bed sediments can be caused by a pumping effect arising when a variable pressure field is created on the stream bottom due to bed

  7. Cooperativity in Surface Bonding and Hydrogen Bonding of Water and Hydroxyl at Metal Surfaces

    DEFF Research Database (Denmark)

    Schiros, T.; Ogasawara, H.; Naslund, L. A.;

    2010-01-01

    of the mixed phase at metal surfaces. The surface bonding can be considered to be similar to accepting a hydrogen bond, and we can thereby apply general cooperativity rules developed for hydrogen-bonded systems. This provides a simple understanding of why water molecules become more strongly bonded...... to the surface upon hydrogen bonding to OH and why the OH surface bonding is instead weakened through hydrogen bonding to water. We extend the application of this simple model to other observed cooperativity effects for pure water adsorption systems and H3O+ on metal surfaces.......We examine the balance of surface bonding and hydrogen bonding in the mixed OH + H2O overlayer on Pt(111), Cu(111), and Cu(110) via density functional theory calculations. We find that there is a cooperativity effect between surface bonding and hydrogen bonding that underlies the stability...

  8. Super water repellent surface 'strictly' mimicking the surface structure of lotus leaf

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Tae Gon; Kim, Ho Young [Seoul National University, Seoul (Korea, Republic of); Yi, Jin Woo; Lee, Kwang Ryeol; Moon, Myoung Woon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2009-07-01

    To achieve the hierarchy of roughness as observed in lotus leaves, most artificial water-repellent surfaces have nano-asperities on top of micropillars. However, observation of real lotus leaves through SEM reveals that nonoscale roughness covers the entire surface including the base as well as bumps. Thus we fabricate surfaces having the same hierarchical roughness structure as the lotus leaf by forming nanopillars on both micropillars and base. We compare the measures of water-repellency (static contact angle, contact angle hysteresis, and transition pressure between the Cassie and Wenzel states) of the lotus-like surface with those of surfaces having single micro- and nano- roughness. The results show that nanoscale roughness covering entire surface area leads to superior water-repellency to other surface roughness structures. We also give a theoretical consideration of this observation.

  9. Simulation method for determining biodegradation in surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Schoeberl, P.; Guhl, W. [Henkel KGaA, Duesseldorf (Germany). Hauptabteilung Oekologie; Scholz, N. [OXENO GmbH, Marl (Germany); Taeger, K. [BASF AG, Ludwigshafen am Rhein (Germany)

    1998-07-01

    OECD guidelines and EU directives on the biological testing of chemicals contain no methods able to simulate biodegradation in surface waters. The surface water simulation method presented in this paper is suitable for closing this gap. The species in the autochthonous biocoenosis used in the method form part of the food web in natural surface waters. The microbial degradation activity measured by the half-life is comparable with that in surface waters. The degrees of degradation measured in this surface water simulation method can be applied to natural surface waters. (orig.) [Deutsch] Die OECD- und EU-Richtlinien zur biologischen Pruefung von Chemikalien enthalten kein Verfahren, mit dem der biologische Abbau in Fliessgewaessern simuliert werden kann. Das in dieser Arbeit vorgestellte Fliessgewaesser-Simulationsmodell ist geeignet, diese Luecke zu schliessen. Die Arten der autochthonen Biocoenose des Modells sind Glieder im Nahrungsnetz natuerlicher Fliessgewaesser. Die an der Halbwertszeit gemessene mikrobielle Abbauaktivitaet ist mit derjenigen in Fliessgewaessern vergleichbar. Die im Fliessgewaesser-Simulationsmodell gemessenen Abbaugrade sind auf natuerliche Fliessgewaesser uebertragbar. (orig.)

  10. Chlorine stress mediates microbial surface attachment in drinking water systems.

    Science.gov (United States)

    Liu, Li; Le, Yang; Jin, Juliang; Zhou, Yuliang; Chen, Guowei

    2015-03-01

    Microbial attachment to drinking water pipe surfaces facilitates pathogen survival and deteriorates disinfection performance, directly threatening the safety of drinking water. Notwithstanding that the formation of biofilm has been studied for decades, the underlying mechanisms for the origins of microbial surface attachment in biofilm development in drinking water pipelines remain largely elusive. We combined experimental and mathematical methods to investigate the role of environmental stress-mediated cell motility on microbial surface attachment in chlorination-stressed drinking water distribution systems. Results show that at low levels of disinfectant (0.0-1.0 mg/L), the presence of chlorine promotes initiation of microbial surface attachment, while higher amounts of disinfectant (>1.0 mg/L) inhibit microbial attachment. The proposed mathematical model further demonstrates that chlorination stress (0.0-5.0 mg/L)-mediated microbial cell motility regulates the frequency of cell-wall collision and thereby controls initial microbial surface attachment. The results reveal that transport processes and decay patterns of chlorine in drinking water pipelines regulate microbial cell motility and, thus, control initial surface cell attachment. It provides a mechanistic understanding of microbial attachment shaped by environmental disinfection stress and leads to new insights into microbial safety protocols in water distribution systems.

  11. Calcium carbonate saturation in the surface water of the Arctic Ocean: undersaturation in freshwater influenced shelves

    Directory of Open Access Journals (Sweden)

    M. Chierici

    2009-05-01

    Full Text Available In the summer of 2005, we sampled surface water and measured pH and total alkalinity (AT underway aboard IB Oden along the Northwest Passage from Cape Farwell (South Greenland to the Chukchi Sea. We investigated variability of carbonate system parameters, focusing particularly on carbonate concentration [CO32−] and calcium carbonate saturation states, as related to freshwater addition, biological processes and physical upwelling. Measurements on AT, pH at 15°C, salinity (S and sea surface temperature (SST, were used to calculate total dissolved inorganic carbon (DIC, [CO32−] and saturation of aragonite (ΩAr and calcite (ΩCa in the surface water. The same parameters were measured in the water column of the Bering Strait. Some surface waters in the Canadian Arctic Archipelago (CAA and on the Mackenzie shelf (MS were found to be undersaturated with respect to aragonite (ΩAr<1. In these areas, surface water was low in AT and DIC (<1500 μmol kg−1 relative to seawater and showed low [CO32−]. The low saturation states were probably due to the effect of dilution due from freshwater addition by sea ice melt (CAA and river runoff (MS. High AT and DIC and low pH, corresponded with the lowest [CO32−], ΩAr and ΩCa, observed near Cape Bathurst and along the South Chukchi Peninsula. This was linked to physical upwelling of subsurface water with elevated CO2. Highest surface ΩAr and ΩCa of 3.0 and 4.5, respectively, were found on the Chukchi Sea shelf and in the cold water north of Wrangel Island, which is heavily influenced by high CO2 drawdown and lower DIC from intense biological production. In the western Bering Strait, the cold and saline Anadyr Current carries water that is enriched in AT and DIC from enhanced organic matter remineralization, resulting in

  12. Calcium carbonate saturation in the surface water of the Arctic Ocean: undersaturation in freshwater influenced shelves

    Directory of Open Access Journals (Sweden)

    A. Fransson

    2009-11-01

    Full Text Available In the summer of 2005, we sampled surface water and measured pH and total alkalinity (AT underway aboard IB Oden along the Northwest Passage from Cape Farewell (South Greenland to the Chukchi Sea. We investigated the variability of carbonate system parameters, focusing particularly on carbonate concentration [CO32−] and calcium carbonate saturation states, as related to freshwater addition, biological processes and physical upwelling. Measurements on AT, pH at 15°C, salinity (S and sea surface temperature (SST, were used to calculate total dissolved inorganic carbon (CT, [CO32−] and the saturation of aragonite (ΩAr and calcite (ΩCa in the surface water. The same parameters were measured in the water column of the Bering Strait. Some surface waters in the Canadian Arctic Archipelago (CAA and on the Mackenzie shelf (MS were found to be undersaturated with respect to aragonite (ΩAr<1. In these areas, surface water was low in AT and CT (<1500 μmol kg−1 relative to seawater and showed low [CO32−]. The low saturation states were probably due to the likely the effect of dilution due to freshwater addition by sea ice melt (CAA and river runoff (MS. High AT and CT and low pH, corresponded with the lowest [CO32−], ΩAr and ΩCa, observed near Cape Bathurst and along the South Chukchi Peninsula. This was linked to the physical upwelling of subsurface water with elevated CO2. The highest surface ΩAr and ΩCa of 3.0 and 4.5, respectively, were found on the Chukchi Sea shelf and in the cold water north of Wrangel Island, which is heavily influenced by high CO2 drawdown and lower CT from intense biological production. In the western Bering Strait, the cold and saline Anadyr Current carries water that is enriched in AT and

  13. Water-clay surface interaction: A neutron scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Sobolev, O., E-mail: sobolev38@gmail.com [LGIT, University of Grenoble and CNRS, BP 53-38041 Grenoble (France); Favre Buivin, F. [HES-SO Fribourg, Bd de Perolles 80-CP 32, CH-1705 Fribourg (Switzerland); Kemner, E.; Russina, M. [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Glienicker Strasse 100, D-14109 Berlin (Germany); Beuneu, B. [Laboratoire Leon Brillouin, C.E. Saclay, 91191 Gif sur Yvette (France); Cuello, G.J. [Institut Laue Langevin and Ikerbasque, 6, rue Jules Horowitz, BP 156, 38042 Grenoble, Cedex 9 (France); Charlet, L. [LGIT, University of Grenoble and CNRS, BP 53-38041 Grenoble (France)

    2010-08-23

    Graphical abstract: Interaction between water molecules and internal clay surfaces was studied by means of neutron diffraction and quasielastic neutron scattering. A hydrophobic cation, TMA{sup +} was used to reduce hydration of interlayer cations. - Abstract: The aim of this study was to investigate interaction between water molecules and internal clay surfaces by means of neutron diffraction and quasielastic neutron scattering. A hydrophobic cation, TMA{sup +} (NC{sub 4}H{sub 12}), was used to saturate the interlayer space of nontronite NAu-1 in order to reduce hydration of interlayer cations that could hinder the effects related to the clay-water interactions. The water content was low in order to reduce hydrogen bonding between water molecules. It was found that water molecules form strong hydrogen bonds with surface oxygen atoms of nontronite. The diffusion activation energy value E{sub a} = 29 {+-} 3 kJ/mol was obtained for water molecules hydrating the clay surface. These results confirm the assumption that surfaces of smectite clays with tetrahedral substitutions are hydrophilic.

  14. Dropwise condensation rate of water breath figures on polymer surfaces having similar surface free energies

    Science.gov (United States)

    Ucar, Ikrime O.; Erbil, H. Yildirim

    2012-10-01

    This study investigates the effect of surface roughness, wettability, water contact angle hysteresis (CAH) and wetting hysteresis (WH) of polymeric substrates to the water drop condensation rate. We used five polyolefin coatings whose surface free energies were in a close range of 30-37 mJ/m2 but having different surface roughness and CAH. The formation of water breath figures was monitored at a temperature just below the dew point. The initial number of the condensed droplets per unit area (N0) and droplet surface coverage were determined during the early stage of drop condensation where the droplet coalescence was negligible. It was found that the mean drop diameter of condensed droplets on these polymer surfaces grow according to a power law with exponent 1/3 of time, similar to the previous reports given in the literature. It was determined that surface roughness and corresponding CAH and WH properties of polymers have important effects on the number of nucleation sites and growth rate of the condensed water droplets. N0 values and the surface coverage increased with the increase in surface roughness, CAH and WH of the polymer surfaces. The total condensed water drop volume also increased with the increase in surface roughness in accordance with the increase of the number of nucleated droplets.

  15. Scenarios for the South African Water Sector in 2025

    African Journals Online (AJOL)

    2012-03-20

    Mar 20, 2012 ... water sector institutional landscape in 2025, presents the key forces, introduces the stories, and ... its origin in military applications, with the United States Air ..... precedence, with a view to 'improving the quality of life'; and.

  16. Ecology, water and enterprise development in selected rural South ...

    African Journals Online (AJOL)

    2010-06-28

    Jun 28, 2010 ... He also stressed that: 'communities themselves have become central to their own ... are enterprise ecosystems and their enterprise structures reflect the driving ... area with those of an arid (water-scarce) area should answer.

  17. Key challenges facing water resource management in South Africa

    CSIR Research Space (South Africa)

    Ashton, P

    2008-11-01

    Full Text Available Resource Managers The Dichotomy of Water Source of destruction, dispute and poverty • Drought and desertification • Flooding and erosion • Salinization • Malnutrition and starvation • Contamination • Epidemics and diseases • Dispute...

  18. Water for firefighting in five South African towns

    African Journals Online (AJOL)

    2012-10-22

    Oct 22, 2012 ... extinguished using water from the WDS by connecting firefighting equipment to a fire hydrant at the time of the fire. Most fires were ... identifying 5 phases: ignition; smouldering; flame growth; fully developed .... to test whether.

  19. Funding models for financing water infrastructure in South Africa ...

    African Journals Online (AJOL)

    2012-03-29

    Mar 29, 2012 ... ing infrastructure with pricing at marginal costs or on a loss-making basis, with returns recovered .... Long-term capital financing models for water infrastruc- .... assets-charge for the relevant scheme or system (DWAF, 2007).

  20. promoting integrated water resources management in south west

    African Journals Online (AJOL)

    eobe

    was that many of the professionals in the water sector organizations ( .... project basis as a "tack-on" to the main contract of ... natural asset that needs to be maintained to ensure ..... in Figure 2, through joint research, education, training,.

  1. Assessing urban water sustainability in South Africa – not just ...

    African Journals Online (AJOL)

    cal system (the urban water cycle), whilst recognising that the system resides within an ... scenario planning, but is also about developing methodologies that prioritise .... a decision support framework; it should also take into account adaptive ...

  2. Establishing an environmental profile of water supply in South Africa

    CSIR Research Space (South Africa)

    Brent, AC

    2006-11-01

    Full Text Available -losses in the supply system must receive attention, especially in the municipal-controlled part. Water quality impacts are also important, although through supporting processes, and specifically electricity generation. The boosting requirements attribute most...

  3. Macro-invertebrate decline in surface water polluted with imidacloprid

    NARCIS (Netherlands)

    van Dijk, T.; van Staalduinen, M.A.; van der Sluijs, J.P.

    2013-01-01

    Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expe

  4. Quality of surface and ground waters, Yakima Indian Reservation, Washington, 1973-74

    Science.gov (United States)

    Fretwell, M.O.

    1977-01-01

    This report describes the quality of the surface and ground waters of the Yakima Indian Reservation in south-central Washington, during the period November 1973-October 1974. The average dissolved-solids concentrations ranged from 48 to 116 mg/L (milligrams per liter) in the mountain streams, and from 88 to 372 mg/L in the lowland streams, drains, and a canal. All the mountain streams contain soft water (classified as 0-60 mg/L hardness as CaC03), and the lowland streams, drains, and canal contain soft to very hard water (more than 180 mg/L hardness as CaC03). The water is generally of suitable quality for irrigation, and neither salinity nor sodium hazards are a problem in waters from any of the streams studied. The specific conductance of water from the major aquifers ranged from 20 to 1 ,540 micromhos. Ground water was most dilute in mineral content in the Klickitat River basin and most concentrated in part of the Satus Creek basin. The ground water in the Satus Creek basin with the most concentrated mineral content also contained the highest percentage composition of sulfate, chloride, and nitrate. For drinking water, the nitrate-nitrogen concentrations exceeded the U.S. Public Health Service 's recommended limit of 10 mg/L over an area of several square miles, with a maximum observed concentration of 170 mg/L. (Woodard-USGS).

  5. Monthly sea surface temperature records reconstructed by δ18O of reef-building coral in the east of Hainan Island,South China Sea

    Institute of Scientific and Technical Information of China (English)

    HE; Xuexian(何学贤); LIU; Dunyi(刘敦一); PENG; Zicheng(彭子成); LIU; Weiguo(刘卫国)

    2002-01-01

    Stable oxygen isotopic compositions of a coral colony of Porites lutea obtained on a core allowed the reconstruction of a 56-a (1943-1998) proxy record of the sea surface temperatures. This coral δ18O data are from the east of Hainan Island water (22°20′N, 110°39′E), South China Sea. The relationship between δ18O in the skeletal aragonite carbonate and the sea surface temperature (SST) is SST = -5.36 δ18OPDB-3.51 (r = 0.73, n = 470), dδ18O/d(SST) = -0.187‰/ ℃; and the thermometer was set at monthly resolution. The 56-a (1943-1998) proxy record of the sea surface temperatures reflected the same change trend in the northern part of South China Sea as the air temperature change trend in China.

  6. Practical aspects of tritium measurement in ground and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Nitzsche, O. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik; Hebert, D. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik

    1997-03-01

    Tritium measurements are a powerful tool in hydrological and hydrogeological investigations for detecting mean residence times of several water reservoirs. Due to the low tritium activities in precipitation, ground and surface waters a low level measurement is necessary. Therefore often the liquid scintillation counting after an electrolytic enrichment of water is used. In this paper some practical aspects and problems of measurement are discussed and the problem of contamination in low level laboratories is shown. (orig.)

  7. Assessment of heavy metal river Ingulets surface water pollution

    OpenAIRE

    Trokhymenko, Ganna G.; Tsyhanyuk, Nina V.

    2017-01-01

    The low efficiency of implemented targeted programs to reduce the anthropogenic impact on hydroecosystem and overcoming its negative consequences demand a search for the optimal evidence reasonable decisions to improve the quality of Ingul river water basin for different economic sectors of water resources and the required number and suitable quality. Methodical bases of such research must be based on a detailed and comprehensive study of the hydrochemical regime and surface water quality. Th...

  8. Studies on the prevalence of giardia cysts and cryptosporidium oocysts in South-African water

    CSIR Research Space (South Africa)

    Kfir, R

    1995-01-01

    Full Text Available water samples were-positive). However, the number of cysts isolated per surface water sample was lower on average. Most water purification plants showed effective removal of cysts and oocysts. However, 13% of potable water samples contained protozoan...

  9. Effects of Dimethyl Sulfoxide on Surface Water near Phospholipid Bilayers.

    Science.gov (United States)

    Lee, Yuno; Pincus, Philip A; Hyeon, Changbong

    2016-12-06

    Despite much effort to probe the properties of dimethyl sulfoxide (DMSO) solution, the effects of DMSO on water, especially near plasma membrane surfaces, still remain elusive. By performing molecular dynamics simulations at varying DMSO concentrations (XDMSO), we study how DMSO affects structural and dynamical properties of water in the vicinity of phospholipid bilayers. As proposed by a number of experiments, our simulations confirm that DMSO induces dehydration from bilayer surfaces and disrupts the H-bond structure of water. However, DMSO-enhanced water diffusivity at solvent-bilayer interfaces, an intriguing discovery reported by a spin-label measurement, is not confirmed in our simulations. To resolve this discrepancy, we examine the location of the spin label (Tempo) relative to the solvent-bilayer interface. In accord with the evidence in the literature, our simulations, which explicitly model Tempo-phosphatidylcholine, find that the Tempo moiety is equilibrated at ∼8-10 Å below the bilayer surface. Furthermore, the DMSO-enhanced surface-water diffusion is confirmed only when water diffusion is analyzed around the Tempo moiety that is immersed below the bilayer surface, which implies that the experimentally detected signal of water using Tempo stems from the interior of bilayers, not from the interface. Our analysis finds that the increase of water diffusion below the bilayer surface is coupled to the increase of area per lipid with an increasing XDMSO(≲10mol%). Underscoring the hydrophobic nature of the Tempo moiety, our study calls for careful re-evaluation of the use of Tempo in measurements on lipid bilayer surfaces. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  10. An Ontology Design Pattern for Surface Water Features

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Gaurav [Ohio University; Mark, David [University at Buffalo (SUNY); Kolas, Dave [Raytheon BBN Technologies; Varanka, Dalia [U.S. Geological Survey, Rolla, MO; Romero, Boleslo E [University of California, Santa Barbara; Feng, Chen-Chieh [National University of Singapore; Usery, Lynn [U.S. Geological Survey, Rolla, MO; Liebermann, Joshua [Tumbling Walls, LLC; Sorokine, Alexandre [ORNL

    2014-01-01

    Surface water is a primary concept of human experience but concepts are captured in cultures and languages in many different ways. Still, many commonalities can be found due to the physical basis of many of the properties and categories. An abstract ontology of surface water features based only on those physical properties of landscape features has the best potential for serving as a foundational domain ontology. It can then be used to systematically incor-porate concepts that are specific to a culture, language, or scientific domain. The Surface Water ontology design pattern was developed both for domain knowledge distillation and to serve as a conceptual building-block for more complex surface water ontologies. A fundamental distinction is made in this on-tology between landscape features that act as containers (e.g., stream channels, basins) and the bodies of water (e.g., rivers, lakes) that occupy those containers. Concave (container) landforms semantics are specified in a Dry module and the semantics of contained bodies of water in a Wet module. The pattern is imple-mented in OWL, but Description Logic axioms and a detailed explanation is provided. The OWL ontology will be an important contribution to Semantic Web vocabulary for annotating surface water feature datasets. A discussion about why there is a need to complement the pattern with other ontologies, es-pecially the previously developed Surface Network pattern is also provided. Fi-nally, the practical value of the pattern in semantic querying of surface water datasets is illustrated through a few queries and annotated geospatial datasets.

  11. Viewpoint – Why Has the South African National Water Act Been so Difficult to Implement?

    Directory of Open Access Journals (Sweden)

    Barbara Schreiner

    2013-06-01

    Full Text Available The South African National Water Act (Act 36 of 1998 was hailed by the international water community as one of the most progressive pieces of water legislation in the world, and a major step forward in the translation of the concept of integrated water resources management (IWRM into legislation. It has been widely quoted and referred to, and a number of countries ranging from China to Zambia have used it as an example in the revision of their own water legislation. And yet, 15 years down the line, implementation of the act has been only partially successful. In a number of critical aspects, implementation has, in fact, been weak. This paper sets out some personal reflections on the challenges facing the implementation of this remarkable piece of legislation and on the failure to achieve the initial high ambitions within the South African water sector. Through this process, it may be that there are lessons for other countries and for South Africa itself as it continues to face the challenge of implementation of the National Water Act (NWA.

  12. Assessment of water availability for competing uses using SWAT and WEAP in South Phuthiatsana catchment, Lesotho

    Science.gov (United States)

    Maliehe, Motlatsi; Mulungu, Deogratias M. M.

    2017-08-01

    The study assessed the quantity of surface water in the South Phuthiatsana catchment, estimated flows in ungauged catchments using Soil and Water Assessment Tool (SWAT) and allocated the resources in the catchment using Water Evaluation And Planning (WEAP) model. SWAT model was calibrated from 1979 to 2001, the p-factor was 65%, r_factor 0.58, NS 0.59 and R2 0.59 for calibration and for validation from 2002 to 2013, the p-factor was 57%, the r_factor was 1.34, the NS was 0.52, and R2 was 0.66. The results show the water balance as: 26% of precipitation form streamflow, 41% of the total flow comes from baseflow, while surface runoff accounts for 59%, 14% of precipitation percolates to shallow aquifer, 1% percolates to deep aquifer and 68% of precipitation is lost through evapotranspiration. The WEAP model was calibrated using CG024 and CG084 stations and historical demands. For CG024 calibration (1972-2002) NS was 0.72 and R2 was 0.84 and for validation (2003-2014) the NS was 0.73 and R2 was 0.74. For CG084 calibration (2007-2011) NS and R2 were 0.55 and 0.64 and for validation (2012-2014) the NS and R2 were 0.63 and 0.89 respectively. Two scenarios were evaluated. First for the reference scenario, the Metolong industrial demands of 1.46 Mm3 and environmental demands of 2.29 Mm3 were both not met. Secondly, for the irrigation expansion scenario, increasing irrigation land by 12.3%, a total of 4.44 Mm3 demands were not met (irrigation accounts for 65.65% of the unmet). Therefore, the study recommends an irrigation plan for the catchment. The irrigation plan has to include: irrigation systems designed for the site, meteorological stations and an irrigator's association with experts forming part of the board.

  13. Integrated Water Flow Model (IWFM), A Tool For Numerically Simulating Linked Groundwater, Surface Water And Land-Surface Hydrologic Processes

    Science.gov (United States)

    Dogrul, E. C.; Brush, C. F.; Kadir, T. N.

    2006-12-01

    The Integrated Water Flow Model (IWFM) is a comprehensive input-driven application for simulating groundwater flow, surface water flow and land-surface hydrologic processes, and interactions between these processes, developed by the California Department of Water Resources (DWR). IWFM couples a 3-D finite element groundwater flow process and 1-D land surface, lake, stream flow and vertical unsaturated-zone flow processes which are solved simultaneously at each time step. The groundwater flow system is simulated as a multilayer aquifer system with a mixture of confined and unconfined aquifers separated by semiconfining layers. The groundwater flow process can simulate changing aquifer conditions (confined to unconfined and vice versa), subsidence, tile drains, injection wells and pumping wells. The land surface process calculates elemental water budgets for agricultural, urban, riparian and native vegetation classes. Crop water demands are dynamically calculated using distributed soil properties, land use and crop data, and precipitation and evapotranspiration rates. The crop mix can also be automatically modified as a function of pumping lift using logit functions. Surface water diversions and groundwater pumping can each be specified, or can be automatically adjusted at run time to balance water supply with water demand. The land-surface process also routes runoff to streams and deep percolation to the unsaturated zone. Surface water networks are specified as a series of stream nodes (coincident with groundwater nodes) with specified bed elevation, conductance and stage-flow relationships. Stream nodes are linked to form stream reaches. Stream inflows at the model boundary, surface water diversion locations, and one or more surface water deliveries per location are specified. IWFM routes stream flows through the network, calculating groundwater-surface water interactions, accumulating inflows from runoff, and allocating available stream flows to meet specified or

  14. Coliform Sources and Mechanisms for Regrowth in Household Drinking Water in Limpopo, South Africa.

    Science.gov (United States)

    Mellor, Jonathan E; Smith, James A; Samie, Amidou; Dillingham, Rebecca A

    2013-09-01

    Resource-limited communities throughout the developing world face significant environmental health problems related to the myriad of coliform sources within those communities. This study comprehensively investigated contamination sources and the biological and chemical mechanisms sustaining them in two adjacent communities in rural Limpopo, South Africa. An 8-month study was conducted of household (n = 14) and source water quality, measurements of biofilm layers on the inside of household water storage containers and water transfer devices, and also hand-based coliforms and hand-washing effectiveness. A 7-day water container incubation experiment was also performed to determine the biological and chemical changes that occur in a household water storage container independent of human interference. Results indicate that household drinking water frequently becomes contaminated after collection but before consumption (197 versus 1,046 colony-forming units/100 mL; n = 266; p water treatment and other interventions aimed at maintaining the safe water chain and preventing biological regrowth.

  15. Nonzero Ideal Gas Contribution to the Surface Tension of Water.

    Science.gov (United States)

    Sega, Marcello; Fábián, Balázs; Jedlovszky, Pál

    2017-06-15

    Surface tension, the tendency of fluid interfaces to behave elastically and minimize their surface, is routinely calculated as the difference between the lateral and normal components of the pressure or, invoking isotropy in momentum space, of the virial tensor. Here we show that the anisotropy of the kinetic energy tensor close to a liquid-vapor interface can be responsible for a large part of its surface tension (about 15% for water, independent from temperature).

  16. Ground-water quality in quaternary deposits of the central high plains aquifer, south-central Kansas, 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Water samples from 20 randomly selected domestic water-supply wells completed in the Quaternary deposits of south-central Kansas were collected as part of the High...

  17. Metropolitan Spokane Region Water Resources Study. Appendix A. Surface Water

    Science.gov (United States)

    1976-01-01

    the river as surface supply. This second area lies mostly north of the Spokane River extending up the val- ley known as Rathdrum Prairie and includes...4 10. 2-29 I .~ -A- IvA -4 -4 IS I rp4r 1-4 - 4NCs 4~ 10. 2- 3o * r~tar gg~wr 4 . fAPPENDIX I en00 -4 - r., 0 CM- WMC q ~~0 0r0 4. .44 . VFog 4102A3

  18. Water transport mechanism through open capillaries analyzed by direct surface modifications on biological surfaces

    Science.gov (United States)

    Ishii, Daisuke; Horiguchi, Hiroko; Hirai, Yuji; Yabu, Hiroshi; Matsuo, Yasutaka; Ijiro, Kuniharu; Tsujii, Kaoru; Shimozawa, Tateo; Hariyama, Takahiko; Shimomura, Masatsugu

    2013-10-01

    Some small animals only use water transport mechanisms passively driven by surface energies. However, little is known about passive water transport mechanisms because it is difficult to measure the wettability of microstructures in small areas and determine the chemistry of biological surfaces. Herein, we developed to directly analyse the structural effects of wettability of chemically modified biological surfaces by using a nanoliter volume water droplet and a hi-speed video system. The wharf roach Ligia exotica transports water only by using open capillaries in its legs containing hair- and paddle-like microstructures. The structural effects of legs chemically modified with a self-assembled monolayer were analysed, so that the wharf roach has a smart water transport system passively driven by differences of wettability between the microstructures. We anticipate that this passive water transport mechanism may inspire novel biomimetic fluid manipulations with or without a gravitational field.

  19. Uncertainties in using remote sensing for water use determination: a case study in a heterogeneous study area in South Africa

    Directory of Open Access Journals (Sweden)

    L. A. Gibson

    2010-09-01

    Full Text Available South Africa is a water scarce country where it is important for water managers to have accurate information on water resource occurrence and use. A remote sensing project highlighted many uncertainties in using complex remote sensing models to determine water use in a heterogeneous study area. The severity of the uncertainties was confirmed as the results across the catchment showed a higher total evapotranspiration than precipitation. This paper illustrates some of the uncertainties and limitations using the evapotranspiration component of the water balance as calculated by the Surface Energy Balance System (SEBS model, as an example.

    The introduction of uncertainties in the derivation of evapotranspiration were identified as: (1 sensitivity to land surface and air temperature gradient; (2 the choice of fractional vegetation cover formula; (3 height of wind speed measurement in relation to displacement height indicating a maximum canopy height at which the SEBS model should be used; and (4 study area heterogeneity.

    Uncertainties and errors are compounded when considering that the SEBS model is a complex model, requiring several image processing sequences that are combined to produce the final result. It was shown how the production and propagation of errors in the SEBS model can contribute to uncertainties in flux estimation and ultimately to uncertainties in the estimation of actual evapotranspiration.

  20. Stormwater Priority Pollutants Versus Surface Water Quality Criteria

    DEFF Research Database (Denmark)

    Eriksson, Eva; Ledin, Anna; Baun, Anders

    2011-01-01

    Stormwater in urban areas comprises of a substantial part of the urban water cycle, dominating the flow in many small urban streams, and the pollution levels are sizeable. No stormwater quality criteria were found here and no European or national emission limit values exist. Stormwater pollutants...... however are present in levels exceeding most of the regulated surface water quality criteria and environmental quality standards. Therefore catchment characterisation is needed to chose suitable treatment prior to discharge into receiving surface waters, as the mixing may be insufficient in small streams....

  1. Relations of surface-water quality to streamflow in the Raritan River basin, New Jersey, water years 1976-93

    Science.gov (United States)

    Buxton, Debra E.; Hunchak-Kariouk, Kathryn; Hickman, R. Edward

    1999-01-01

    Relations of water quality to streamflow were determined for 18 water-quality constituents at 21 surface-water stations within the drainage area of the Raritan River Basin for water years 1976-93. Surface-water-quality and streamflow data were evaluated for trends (through time) in constituent concentrations during high and low flows, and relations between constituent concentration and streamflow, and between constituent load and streamflow, were determined. Median concentrations were calculated for the entire period of study (water years 1976-93) and for the last 5 years of the period of study (water years 1989-93) to determine whether any large variation in concentration exists between the two periods. Medians also were used to determine the seasonal Kendall’s tau statistic, which was then used to evaluate trends in concentrations during high and low flows. Trends in constituent concentrations during high and low flows were evaluated to determine whether the distribution of the observations changes through time for intermittent (nonpoint storm runoff) or constant (point sources and ground water) sources, respectively. Highand low-flow trends in concentrations were determined for some constituents at 13 of the 21 water-quality stations; 8 stations have insufficient data to determine trends. Seasonal effects on the relations of concentration to streamflow are evident for 16 of the 18 constituents. Negative slopes of relations of concentration to streamflow, which indicate a decrease in concentration at high flows, predominate over positive slopes because of the dilution of instream concentrations by storm runoff. The slopes of the regression lines of load to streamflow were determined in order to show the relative contributions to the instream load from constant (point sources and ground water) and intermittent sources (storm runoff). Greater slope values indicate larger contributions from storm runoff to instream load, which most likely indicate an increased

  2. Surface Water Resources Response to Climate Changes in Jilin Province

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The response of surface water resources on climate changes was studied.[Method] By dint of monthly average temperature and precipitation in 45 meteorological stations in Jilin Province from 1960 to 2000,monthly runoff in 56 hydrological stations in Songhuajiang and Liaohe region,the surface runoff change and the response of surface water resources to climate change in 41 years were expounded.[Result] The runoff of Songliao region was limited during 1960s and 1970s.It began to increase slowly in ...

  3. The challenges of rescaling South African water resources management: Catchment Management Agencies and interbasin transfers

    Science.gov (United States)

    Bourblanc, Magalie; Blanchon, David

    2014-11-01

    The implementation of Catchment Management Agencies (CMAs) was supposed to be the cornerstone of the rescaling process of the South African water reform policy. Yet, less than 10 years after the adoption of the National Water Act, the process was suspended for 4 years and by 2012 only two CMAs had been established. Combining approaches in geography and political science, this paper investigates the reasons for the delays in CMAs' implementation in South Africa. It shows that the construction of interbasin transfers (IBTs) since the 1950s by the apartheid regime and nowadays the power struggles between CMAs and the Department of Water Affairs (DWA) are two of the main obstacles to the creation of CMAs planned by the 1998 National Water Act (NWA). Finally, the paper advocates taking the "hydrosocial cycle" as an analytical framework for designing new institutional arrangements that will include both rectifying the legacy of the past (the specific role of DWA) and acknowledging legitimate local interests.

  4. Climate Change Vulnerability Assessment for Water Resources Planning in South Florida

    Science.gov (United States)

    Irizarry-Ortiz, M. M.; Barnes, J. A.; Dessalegne-Agaze, T.; Trimble, P.; Obeysekera, J.

    2008-05-01

    The IPCC Fourth Assessment Report (AR4) concludes that the "warming of the climate system is unequivocal." The AR4 includes projections of climate change based on General Circulation Model (GCM) simulation results for a series of green-house gas emission scenarios. Volume II of the AR4 report discusses potential impacts of climate change, adaptation measures, and vulnerability of coastal systems and low-lying areas. However, these assessments are limited to potential regional scale impacts and are not detailed nor certain enough to provide meaningful guidance for water resources management and planning at local scales. South Florida is home to 7.5 million people and has one of the most heavily managed water control systems in the world. Given uncertainties in the IPCC predictions, key vulnerabilities must be identified and addressed. Due to its low topographic relief, the region is extremely vulnerable to sea-level rise (SLR) with implications for water supply and flood control management. Due to the extremely porous nature of the groundwater system, the main source for water supply in south Florida, saltwater intrusion into coastal wellfields is of concern. SLR also reduces the flood control capacity of coastal gravity structures with serious implications. Precipitation and evapotranspiration are very close in magnitude for south Florida. Changes to either of these components as a result of climate change have implications for water resources planning and management. The south Florida climate is largely influenced by teleconnections to ENSO, AMO, PDO. To the degree that GCMs capture these phenomena, meaningful projections can be made for south Florida. Given uncertainties in GCM predictions for the region, statistical or dynamic downscaling methods may not provide additional value. Therefore, until the state of the science can provide more consistent and meaningful predictions for the region, a wide range of scenarios must be considered and it becomes imperative

  5. Records of wells and chemical analyses of ground water in Hand and Hyde counties, South Dakota

    Science.gov (United States)

    Neitzert, K.M.; Koch, N.C.

    1987-01-01

    Well and chemical groundwater data contained in three tables were collected during a 4-year study started in 1972 to determine the geology and water resources of Hand and Hyde Counties, South Dakota. Physical, hydrologic, and geologic data for 2,729 wells and test holes have been entered into computer storage in the Groundwater Site Inventory File of the U.S. Geological Survey 's National Water Data Storage and Retrieval System WATSTORE. Water quality data from 300 chemical analyses has been stored in the Water Quality File of WATSTORE and is computer printed int he chemical analyses table by aquifer. (USGS)

  6. Exploring the government society and science interfaces in integrated water resource management in South Africa

    CSIR Research Space (South Africa)

    Ashton, PJ

    2006-12-01

    Full Text Available as the goods and services that are derived from or linked to such water use (Van Wyk et al. 2006). The focus on greater equity within South Africa’s new water policy requires stakeholders to shift away from rights-based water allocations to a system where.... These drivers can be represented as axes on a matrix (Figure 1), where the general trend of change is shown as a progressive broadening of the scope of water resource management envelopes from (A) to (C) over time. The upper left-hand quadrant represents...

  7. Change in diarrhoea trends and the increasing importance of microbiological water quality due to HIV/AIDS in South Africa

    CSIR Research Space (South Africa)

    Steyn, M

    2009-05-01

    Full Text Available and the increasing importance of microbiological water quality due to HIV/AIDS in South Africa MARONEL STEYN AND BETTINA GENTHE CSIR Natural Resources and the Environment, Stellenbosch, Cape Town, 7599, South Africa Email: msteyn@csir.co.za – www.csir.co.za In... potential risk for microbiological contamination of treated water supplies and associated diarrhoeal disease burden. Correlation of factors potentially contributing to diarrhoeal disease in South Africa # diarrhoea episodes in < 5 yrs Number...

  8. Seasonal occurrence and distribution of a group of ECs in the water resources of Granada city metropolitan areas (South of Spain): Pollution of raw drinking water

    Science.gov (United States)

    Luque-Espinar, Juan Antonio; Navas, Natalia; Chica-Olmo, Mario; Cantarero-Malagón, Samuel; Chica-Rivas, Lucía

    2015-12-01

    This piece of research deals with the monitoring of a group of emerging contaminants (ECs) in the metropolitan area of Granada, a city representative of the South of Spain, in order to evaluate the environmental management of the wastewater system. With that aim, the spatial and seasonal occurrence and distribution of a group of ECs in groundwater, surface and irrigation water resources from the aquifer "Vega de Granada" (VG) have been investigated for the first time. A set of the most prescribed drugs in Spain (ibuprofen, loratadine, pantoprazole and paracetamol), a pesticide widely used in agriculture (atrazine) and a typical anthropogenic contaminant (caffeine) were included in the study. Water samples were taken from the metropolitan area of the city of Granada inside of the zone of the aquifer, from the downstream of two waste water treatment plants (WWTPs) and from the two main irrigation channels where surface and wastewater are mixed before distribution for irrigation purposes in the crops of the study area. A total of 153 water samples were analyzed through liquid chromatography coupled with mass spectrometry (LC-MS/MS) throughout the study that took place over a period of two years, from July 2011 to July 2013. Results demonstrated the occurrence of four of the six target pollutants. Ibuprofen was detected several times, always in both channels with concentration ranges from 5.3 to 20.8 μg/L. The occurrence of paracetamol was detected in rivers and channels up to 34.3 μg/L. Caffeine was detected in all the water resources up to 39.3 μg/L. Pantoprazole was detected twice in the surface water source near to a WWPT ranging from 0.02 to 0.05 μg/L. The pesticide atrazine and the drug loratadine were not detected in any of the water samples analyzed. These results show evidence of poor environmental management of the wastewater concerning the water quality of the aquifer studied. The groundwater sources seem to receive a very continuous input of wastewater

  9. The Proposed Surface Water and Ocean Topography (SWOT) Mission

    Science.gov (United States)

    Fu, Lee-Lueng; Alsdorf, Douglas; Rodriguez, Ernesto; Morrow, Rosemary; Mognard, Nelly; Vaze, Parag; Lafon, Thierry

    2012-01-01

    A new space mission concept called Surface Water and Ocean Topography (SWOT) is being developed jointly by a collaborative effort of the international oceanographic and hydrological communities for making high-resolution measurement of the water elevation of both the ocean and land surface water to answer the questions about the oceanic submesoscale processes and the storage and discharge of land surface water. The key instrument payload would be a Ka-band radar interferometer capable of making high-resolution wide-swath altimetry measurement. This paper describes the proposed science objectives and requirements as well as the measurement approach of SWOT, which is baselined to be launched in 2019. SWOT would demonstrate this new approach to advancing both oceanography and land hydrology and set a standard for future altimetry missions.

  10. The influence of lithology on surface water sources | Science ...

    Science.gov (United States)

    Understanding the temporal and spatial variability of surface water sources within a basin is vital to our ability to manage the impacts of climate variability and land cover change. Water stable isotopes can be used as a tool to determine geographic and seasonal sources of water at the basin scale. Previous studies in the Coastal Range of Oregon reported that the variation in the isotopic signatures of surface water does not conform to the commonly observed “rainout effect”, which exhibits a trend of increasing isotopic depletion with rising elevation. The primary purpose of this research is to investigate the mechanisms governing seasonal and spatial variations in the isotopic signature of surface waters within the Marys River Basin, located in the leeward side of the Oregon Coastal Range. Surface water and precipitation samples were collected every 2-3 weeks for isotopic analysis of δ18O and δ2H for one year. Results indicate a significant difference in isotopic signature between watersheds underlain by basalt and sandstone. The degree of separation was the most distinct during the summer when low flows reflect deeper groundwater sources, whereas isotopic signatures during the rainy season (fall and winter) showed a greater degree of similarity between the two lithologies. This indicates that baseflow within streams drained by sandstone versus basalt is being supplied from two distinctly separate water sources. In addition, Marys River flow at the outle

  11. Physico-Chemical and Microbial Analysis of Selected Borehole Water in Mahikeng, South Africa

    OpenAIRE

    Lobina Palamuleni; Mercy Akoth

    2015-01-01

    Groundwater is generally considered a “safe source” of drinking water because it is abstracted with low microbial load with little need for treatment before drinking. However, groundwater resources are commonly vulnerable to pollution, which may degrade their quality. An assessment of microbial and physicochemical qualities of borehole water in the rural environs of Mahikeng town, South Africa, was carried out. The study aimed at determining levels of physicochemical (temperature, pH, turbidi...

  12. Nutrient characterisation of river inflow into the estuaries of the Gouritz Water Management Area, South Africa

    CSIR Research Space (South Africa)

    Lemley, DA

    2014-10-01

    Full Text Available cycling (Buzzelli et al., 2007; Buzzelli, 2012). A great deal of emphasis has been placed on determining the consequences of these anthropogenic stressors on estuaries through the use of monitoring programmes (Carstensen et al., 2012). In South Africa... systems. Assessing the effectiveness and compliance of WWTPs is essential to providing a complete and holis- tic overview of water quality inputs into the estuaries of the Gouritz WMA. Effluents from WWTPs are discharged to sur- face waters, after...

  13. Suspended redistribution: ‘green economy’ and water inequality in the Waterberg, South Africa

    NARCIS (Netherlands)

    M. Marcatelli (Michela)

    2015-01-01

    textabstractIn this article I show how ideas and practices of ‘green economy’ can reproduce and even naturalise inequality in water access for local users. Evidence to support my argument is drawn from the Waterberg region in the Limpopo Province of South Africa. Following the demise of apartheid an

  14. On the waterfront: water distribution, technology and agrarian change in a south India canal irrigation system.

    NARCIS (Netherlands)

    Mollinga, P.P.

    1998-01-01

    This book discusses water distribution in the Tungabhadra Left Bank Canal irrigation system in Raichur district, Karnataka, India. The system is located in interior South India, where rainfall is limited (approximately 600 mm annually) and extremely variable. The region suffered from failed harvests

  15. Hydro-ecological relations in the Delta Waters of the South-West Netherlands

    NARCIS (Netherlands)

    Baptist, H.J.M.; Bijlsma, I.; Engel, H.; Haperen, A.A.M. van; Hoog, J.E.W. de; Iedema, C.W.; Kuipers, J.W.M.; Meininger, P.L.; Meire, P.M.; Mulder, J.P.M.; Nienhuis, P.H.; Seys, J.; Steenkamp, B.P.C.; Ysebaert, T.

    1989-01-01

    Before human interference in the Delta of the South-West Netherlands, the hydro-ecological relations in the waters of this Delta were taken very much for granted. As a result of the man-made changes, the natural relations disappeared. The construction of the Delta Works completely altered the face

  16. Hydro-ecological relations in the Delta Waters of the South-West Netherlands

    NARCIS (Netherlands)

    Baptist, H.J.M.; Bijlsma, I.; Engel, H.; Haperen, A.A.M. van; Hoog, J.E.W. de; Iedema, C.W.; Kuipers, J.W.M.; Meininger, P.L.; Meire, P.M.; Mulder, J.P.M.; Nienhuis, P.H.; Seys, J.; Steenkamp, B.P.C.; Ysebaert, T.

    1989-01-01

    Before human interference in the Delta of the South-West Netherlands, the hydro-ecological relations in the waters of this Delta were taken very much for granted. As a result of the man-made changes, the natural relations disappeared. The construction of the Delta Works completely altered the face o

  17. Crop-specific seasonal estimates of irrigation-water demand in South Asia

    NARCIS (Netherlands)

    Biemans, Hester; Siderius, Christian; Mishra, Ashok; Ahmad, Bashir

    2016-01-01

    Especially in the Himalayan headwaters of the main rivers in South Asia, shifts in runoff are expected as a result of a rapidly changing climate. In recent years, our insight into these shifts and their impact on water availability has increased. However, a similar detailed understanding of the s

  18. On the waterfront : water distribution, technology and agrarian change in a South Indian canal irrigation system

    NARCIS (Netherlands)

    Mollinga, P.P.

    1998-01-01

    This book discusses water distribution in the Tungabhadra Left Bank Canal irrigation system in Raichur district, Karnataka, India. The system is located in interior South India, where rainfall is limited (approximately 600 mm annually) and extremely variable. The region suffered from failed

  19. Reproductive system of the giant squid Architeuthis in South African waters

    NARCIS (Netherlands)

    Hoving, HJT; Roeleveld, MAC; Lipinski, MR; Melo, Y

    2004-01-01

    The reproductive system is described from 15 giant squid Architeuthis sp., collected between 1972 and 2002 in South African waters. Distinctive features of the mate reproductive system are the long muscular terminal organ, with elaboration of the anterior end, and modification of the tips of the

  20. Hydro-ecological relations in the Delta Waters of the South-West Netherlands

    NARCIS (Netherlands)

    Baptist, H.J.M.; Bijlsma, I.; Engel, H.; Haperen, A.A.M. van; Hoog, J.E.W. de; Iedema, C.W.; Kuipers, J.W.M.; Meininger, P.L.; Meire, P.M.; Mulder, J.P.M.; Nienhuis, P.H.; Seys, J.; Steenkamp, B.P.C.; Ysebaert, T.

    1989-01-01

    Before human interference in the Delta of the South-West Netherlands, the hydro-ecological relations in the waters of this Delta were taken very much for granted. As a result of the man-made changes, the natural relations disappeared. The construction of the Delta Works completely altered the face o

  1. Funding models for financing water infrastructure in South Africa: framework and critical analysis of alternatives

    CSIR Research Space (South Africa)

    Ruiters, C

    2013-04-01

    Full Text Available public provision model continues to characterise much of the publicly-provided water infrastructure in South Africa. These models see Government planning, installing and financing infrastructure with pricing at marginal costs or on a loss-making basis...

  2. Inland water ecosystems in South Africa – a review of research needs.

    CSIR Research Space (South Africa)

    Noble, RG

    1978-11-01

    Full Text Available expressed by Dr A F Bartsch (US Environmental Protection Agency) who visited South Africa in March 1977 as a consultant to the Water Research Commission. It has been drawn up with both limnologists and decision makers in mind, in order to facilitate...

  3. Addressing stakeholder conflicts in rural South Africa using a water supply model

    NARCIS (Netherlands)

    D' Hont, F.M.; Clifford-Holmes, J.K.; Slinger, J.H.

    2013-01-01

    A system dynamics modelling approach is adopted to deepen understanding of the effects of operational management on the performance of the Greater Kirkwood water supply system in South Africa. Currently, the interrupted operation of the system has led to perceptions of systemic social injustice on t

  4. What does research have to say about South Africa's water institutions?

    CSIR Research Space (South Africa)

    Funke, Nicola S

    2014-01-01

    Full Text Available 2014/Vol. 13(1) What does research have to say about SOUTH AFRICA’S WATER INSTITUTIONS? Nikki Funke, Richard Meissner, Shanna Nienaber and Cebile Ntombela. CSIR Natural Resources and Environment. Abstract It has been 16 years since...

  5. Composition and possible function of social groupings of southern right whales in South African waters

    NARCIS (Netherlands)

    Best, PB; Schaeff, CM; Reeb, D; Palsboll, PJ

    2003-01-01

    We collected behavioural data and skin samples for molecular sex determination from 327 right whales (Eubalaena australis) in the coastal waters of South Africa between July and October, 1995 and 1996, as well as from 147 cows with calves-of-the-year between August and October 1996, September and No

  6. Surface water waves due to an oscillatory wavemaker in the presence of surface tension

    Directory of Open Access Journals (Sweden)

    B. N. Mandal

    1992-01-01

    Full Text Available The initial value problem of generation of surface water waves by a harmonically oscillating plane vertical wavemaker in an infinite incompressible fluid under the action of gravity and surface tension is investigated. In the asymptotic evaluation of the free surface depression for large time and distance, the contribution to the integral by stationary phase method gives rise to transient component of the free surface depression while the contribution from the poles give rise to steady state component. It is observed that the presence of surface tension sometimes changes the qualitative nature of the transient component of free surface depression.

  7. The hydrological characterisation and water budget of a South ...

    African Journals Online (AJOL)

    2012-02-01

    Feb 1, 2012 ... regions; third, southern Africa has significantly lower average rainfall than other ... hence high variability in geo- and meteorological characteris- tics, no unifying model ... source of water to the dambo is derived from direct rainfall; interfluve .... a University of KwaZulu-Natal timing board system. This allowed ...

  8. Benchmarking leakage from water reticulation systems in South Africa

    African Journals Online (AJOL)

    driniev

    was considered worthwhile to build on the previous work and to .... 8 has a very high ILI value due to the high difference in input ..... to generate water accounts when a meter ... magnets to interfere with the correct rotation of the register and.

  9. Pathways of upwelling deep waters to the surface of the Southern Ocean

    Science.gov (United States)

    Tamsitt, Veronica; Drake, Henri; Morrison, Adele; Talley, Lynne; Dufour, Carolina; Gray, Alison; Griffies, Stephen; Mazloff, Matthew; Sarmiento, Jorge; Wang, Jinbo; Weijer, Wilbert

    2017-04-01

    Upwelling of Atlantic, Indian and Pacific deep waters to the sea surface in the Southern Ocean closes the global overturning circulation and is fundamentally important for oceanic uptake of anthropogenic carbon and heat, nutrient resupply for sustaining oceanic biological production, and the melt rate of ice shelves. Here we go beyond the two-dimensional view of Southern Ocean upwelling, to show detailed Southern Ocean upwelling pathways in three dimensions, using hydrographic observations and particle tracking in high-resolution ocean and climate models. The northern deep waters enter the Antarctic Circumpolar Current (ACC) via narrow southward currents along the boundaries of the three ocean basins, before spiraling southeastward and upward through the ACC. Upwelling is greatly enhanced at five major topographic features, associated with vigorous mesoscale eddy activity. Deep water reaches the upper ocean predominantly south of the southern ACC boundary, with a spatially nonuniform distribution, regionalizing warm water supply to Antarctic ice shelves and the delivery of nutrient and carbon-rich water to the sea surface. The timescale for half of the deep water to upwell from 30°S to the mixed layer is on the order of 60-90 years, which has important implications for the timescale for signals to propagate through the deep ocean. In addition, we quantify the diabatic transformation along particle trajectories, to identify where diabatic processes are important along the upwelling pathways.

  10. Surface tension isotherms of the dioxane-acetone-water and glycerol-ethanol-water ternary systems

    Science.gov (United States)

    Dzhambulatov, R. S.; Dadashev, R. Kh.; Elimkhanov, D. Z.; Dadashev, I. N.

    2016-10-01

    The results of the experimental and theoretical studies of the concentration dependence of surface tension of aqueous solutions of the 1,4-dioxane-acetone-water and glycerol-ethanol-water ternary systems were given. The studies were performed by the hanging-drop method on a DSA100 tensiometer. The maximum error of surface tension was 1%. The theoretical models for calculating the surface tension of the ternary systems of organic solutions were analyzed.

  11. Supplementary report on surface-water and ground-water surveys, Nueces River Basin, Texas

    Science.gov (United States)

    Broadhurst, W.L.; Ellsworth, C.E.

    1950-01-01

    A report on the ground-water and surface-water surveys of the Nueces River Basin was included in a report by the Bureau of Reclamation, entitled "Comprehensive plan for water-resources development of the Nueces River Basin project planning report number 5-14.04-3, February 1946".

  12. Assessment for water quality by artificial neural network in Daya Bay, South China Sea.

    Science.gov (United States)

    Wu, Mei-Lin; Wang, You-Shao; Gu, Ji-Dong

    2015-10-01

    In this study, artificial neural network such as a self-organizing map (SOM) was used to assess for the effects caused by climate change and human activities on the water quality in Daya Bay, South China Sea. SOM has identified the anthropogenic effects and seasonal characters of water quality. SOM grouped the four seasons as four groups (winter, spring, summer and autumn). The Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on the water quality in Daya Bay. Spatial pattern is mainly related to anthropogenic activities and hydrodynamics conditions. In spatial characteristics, the water quality in Daya Bay was divided into two groups by chemometrics. The monitoring stations (S3, S8, S10 and S11) were in these area (Dapeng Ao, Aotou Harbor) and northeast parts of Daya Bay, which are areas of human activity. The thermal pollution has been observed near water body in Daya Bay Nuclear Power Plant (S5). The rest of the monitoring sites were in the south, central and eastern parts of Daya Bay, which are areas that experience water exchanges from South China Sea. The results of this study may provide information on the spatial and temporal patterns in Daya Bay. Further research will be carry out more research concerning functional changes in the bay ecology with respect to changes in climatic factor, human activities and bay morphology in Daya Bay.

  13. Microplastics in Arctic polar waters: the first reported values of particles in surface and sub-surface samples

    Science.gov (United States)

    Lusher, Amy L.; Tirelli, Valentina; O'Connor, Ian; Officer, Rick

    2015-10-01

    Plastic, as a form of marine litter, is found in varying quantities and sizes around the globe from surface waters to deep-sea sediments. Identifying patterns of microplastic distribution will benefit an understanding of the scale of their potential effect on the environment and organisms. As sea ice extent is reducing in the Arctic, heightened shipping and fishing activity may increase marine pollution in the area. Microplastics may enter the region following ocean transport and local input, although baseline contamination measurements are still required. Here we present the first study of microplastics in Arctic waters, south and southwest of Svalbard, Norway. Microplastics were found in surface (top 16 cm) and sub-surface (6 m depth) samples using two independent techniques. Origins and pathways bringing microplastic to the Arctic remain unclear. Particle composition (95% fibres) suggests they may either result from the breakdown of larger items (transported over large distances by prevailing currents, or derived from local vessel activity), or input in sewage and wastewater from coastal areas. Concurrent observations of high zooplankton abundance suggest a high probability for marine biota to encounter microplastics and a potential for trophic interactions. Further research is required to understand the effects of microplastic-biota interaction within this productive environment.

  14. Using IR Imaging of Water Surfaces for Estimating Piston Velocities

    Science.gov (United States)

    Gålfalk, M.; Bastviken, D.; Arneborg, L.

    2013-12-01

    The transport of gasses dissolved in surface waters across the water-atmosphere interface is controlled by the piston velocity (k). This coefficient has large implications for, e.g., greenhouse gas fluxes but is challenging to quantify in situ. At present, empirical k-wind speed relationships from a small number of studies and systems are often extrapolated without knowledge of model performance. It is therefore of interest to search for new methods for estimating k, and to compare the pros and cons of existing and new methods. Wind speeds in such models are often measured at a height of 10 meters. In smaller bodies of water such as lakes, wind speeds can vary dramatically across the surface through varying degrees of wind shadow from e.g. trees at the shoreline. More local measurements of the water surface, through wave heights or surface motion mapping, could give improved k-estimates over a surface, also taking into account wind fetch. At thermal infrared (IR) wavelengths water has very low reflectivity (depending on viewing angle) than can go below 1%, meaning that more than 99% is heat radiation giving a direct measurement of surface temperature variations. Using an IR camera at about 100 frames/s one could map surface temperature structures at a fraction of a mm depth even with waves present. In this presentation I will focus on IR imaging as a possible tool for estimating piston velocities. Results will be presented from IR field measurements, relating the motions of surface temperature structures to k calculated from other simultaneous measurements (flux chamber and ADV-Based Dissipation Rate), but also attempting to calculate k directly from the IR surface divergence. A relation between wave height and k will also be presented.

  15. WATER QUALITY MODELING AND POLLUTION CONTROL FOR THE EASTERN ROUTE OF SOUTH TO NORTH WATER TRANSFER PROJECT IN CHINA

    Institute of Scientific and Technical Information of China (English)

    WANG Chao; WANG Yan-ying; WANG Pei-fang

    2006-01-01

    South to North Water Transfer Project in China is the largest project over centuries to solve the water shortage problem in vast areas of northern China. It comprises of three routes: the eastern, central and western route and this study mainly focused on the eastern route. As water quality is the key factor for the eastern route, this paper examined the main factors influencing water quality of the main route south of the Yellow River, by investigating the point source, non-point source (diffusive source) and internal source pollutions along the main eastern route and in its drainage basins, and assessing the current water quality in the waterways. According to the complicated and combined systems of rivers and lakes in this route, one-dimensional water quantity and quality model for rivers and two-dimensional model for lakes were developed to simulate the hydrodynamic and pollutant transport processes. The numerical method and model algorithm were described. The values of model parameters were estimated by using field-monitoring data along the main route and the inverse modeling technique. Established models were employed to predict the degradations of CODMn and NH4+-N in the main stream, under the conditions of current pollution loads and different hydrologic conditions. Schemes were present for controlling total quantities of pollutants from point source and non-point source along the main route to secure water quality for the eastern route.

  16. Surface signature of Mediterranean water eddies in the Northeastern Atlantic: effect of the upper ocean stratification

    Directory of Open Access Journals (Sweden)

    I. Bashmachnikov

    2012-11-01

    Full Text Available Meddies, intra-thermocline eddies of Mediterranean water, can often be detected at the sea surface as positive sea-level anomalies. Here we study the surface signature of several meddies tracked with RAFOS floats and AVISO altimetry.

    While pushing its way through the water column, a meddy raises isopycnals above. As a consequence of potential vorticity conservation, negative relative vorticity is generated in the upper layer. During the initial period of meddy acceleration after meddy formation or after a stagnation stage, a cyclonic signal is also generated at the sea-surface, but mostly the anticyclonic surface signal follows the meddy.

    Based on geostrophy and potential vorticity balance, we present theoretical estimates of the intensity of the surface signature. It appears to be proportional to the meddy core radius and to the Coriolis parameter, and inversely proportional to the core depth and buoyancy frequency. This indicates that surface signature of a meddy may be strongly reduced by the upper ocean stratification. Using climatic distribution of the stratification intensity, we claim that the southernmost limit for detection in altimetry of small meddies (with radii on the order of 10–15 km should lie in the subtropics (35–45° N, while large meddies (with radii of 25–30 km could be detected as far south as the northern tropics (25–35° N. Those results agree with observations.

  17. Water: a neglected nutrient in the young child? A South African perspective.

    Science.gov (United States)

    Bourne, Lesley T; Harmse, Berna; Temple, Norman

    2007-10-01

    Water is considered an essential nutrient because the body cannot produce enough water itself, by metabolism of food, to fulfil its need. When the quantity or quality of water is inadequate, health problems result, most notably dehydration and diarrhoea. As a result of contaminated water and poor hygiene, related infections are still a serious problem. Indeed, in the South African setting water availability and sanitation are critical issues because of the prevalence of childhood diarrhoea and also the HIV/AIDS crisis. Though considerable efforts have been made to improve the water and sanitation problems in South Africa - especially with regard to water supply infrastructure - there is still room for much improvement. Water is a healthy alternative to calorie-dense, non-nutritive beverages, such as artificial fruit drinks and soda. The latter should be avoided as they contribute little other than energy and may contribute to overweight and obesity. Also, they displace more nutritious foods from the child's diet. Consumption of fruit juice should also be limited. These issues highlight the need for a specific guideline relating to water intake in the paediatric food-based dietary guidelines.

  18. Foulant characteristics comparison in recycling cooling water system makeup by municipal reclaimed water and surface water in power plant.

    Science.gov (United States)

    Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si

    2015-01-01

    Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS), protein (PN), and polysaccharide (PS) in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water.

  19. Molecular Dynamics Simulations of Water Nanodroplets on Silica Surfaces

    DEFF Research Database (Denmark)

    Zambrano, Harvey A; Walther, Jens Honore; Jaffe, Richard L.

    2009-01-01

    and DNA microarrays technologies.4,5,6,7,8 Although extensive experimental, theoretical and computational work has been devoted to study the nature of the interaction between silica and water,2,9-16 at the molecular level a complete understanding of silica-water systems has not been reached. Contact angle...... computations of water droplets on silica surfaces offers a useful fundamental and quantitative measurement in order to study chemical and physical properties of water-silica systems.3,16,17,18 For hydrophobic systems the static and dynamic properties of the fluid-solid interface are influenced by the presence...

  20. Understanding land surface response to changing South Asian monsoon in a warming climate

    Directory of Open Access Journals (Sweden)

    M. V. S. Ramarao

    2015-05-01

    Full Text Available Recent studies have drawn attention to a significant weakening trend of the South Asian monsoon circulation and an associated decrease in regional rainfall during the last few decades. While surface temperatures over the region have steadily risen during this period, most of the CMIP (Coupled Model Intercomparison Project global climate models have difficulties in capturing the observed decrease of monsoon precipitation, thus limiting our understanding of the regional land surface response to monsoonal changes. This problem is investigated by performing two long-term simulation experiments, with and without anthropogenic forcing, using a variable resolution global climate model having high-resolution zooming over the South Asian region. The present results indicate that anthropogenic effects have considerably influenced the recent weakening of the monsoon circulation and decline of precipitation. It is seen that the simulated increase of surface temperature over the Indian region during the post-1950s is accompanied by a significant decrease of monsoon precipitation and soil moisture. Our analysis further reveals that the land surface response to decrease of soil moisture is associated with significant reduction in evapotranspiration over the Indian land region. A future projection, based on the representative concentration pathway 4.5 (RCP4.5 scenario of the Intergovernmental panel on Climate Change (IPCC, using the same high-resolution model indicates the possibility for detecting the summer-time soil drying signal over the Indian region during the 21st century, in response to climate change. While these monsoon hydrological changes have profound socioeconomic implications, the robustness of the high-resolution simulations provides deeper insights and enhances our understanding of the regional land surface response to the changing South Asian monsoon.

  1. Preservation of Radiolarian Diversity and Abundance in Surface Sediments of the South China Sea and Its Environmental Implication

    Institute of Scientific and Technical Information of China (English)

    Chen Muhong; Zhang Lanlan; Zhang Lili; Xiang Rong; Lu Jun

    2008-01-01

    Quantitative analysis of radiolarian preservation in surface sediments from different regional environments of the South China Sea (SCS) is discussed in this article for illustrating their relationship. The results show that species diversity and abundance of radiolarian in the surfacese diment increase with water depth, indicating no obvious dissolution of radiolarian shell in the deep SCS. Upwelling activity and volcanic eruption are both in favor of radiolarian propagation, and cause the settlement enrichment of radiolarian shell. Whereas, an abnormal reduced radiolarian fauna in deeper slope sediment may result from the remain of turbid flow that brings sediments from shallow area, such as shelf and upper slope. Radiolartan species are mainly composed of tropic-subtropic types,and include some cold or polar species, which indicates that a mistake in paleoceanographic analysis should arise from the monospecific index. However, synthesis radiolarian indexes in sediments may well respond to the ecologic and depositional environments in the SCS.

  2. A Mechanism for Near-Surface Water Ice on Mars

    Science.gov (United States)

    Travis, B. J.; Feldman, W. C.; Maurice, S.

    2009-12-01

    Recent findings (e.g., Byrne et al, 2009) indicate that water ice lies very close to the surface at mid-latitudes on Mars. Re-interpretation of neutron and gamma-ray data is consistent with water ice buried less than a meter or two below the surface. Hydrothermal convection of brines provides a mechanism for delivering water to the near-surface. Previous numerical and experimental studies with pure water have indicated that hydrothermal circulation of pore water should be possible, given reasonable estimates of geothermal heat flux and regolith permeability. For pure water convection, the upper limit of the liquid zone would lie at some depth, but in the case of salt solutions, the boundary between liquid and frozen pore water could reach virtually to the surface. The principal drivers for hydrothermal circulation are regolith permeability, geothermal heat flux, surface temperature and salt composition. Both the Clifford and the Hanna-Phillips models of Martian regolith permeability predict sufficiently high permeabilities to sustain hydrothermal convection. Salts in solution will concentrate in upwelling plumes as the cold surface is approached. As water ice is excluded upon freezing, the remaining solution becomes a more concentrated brine, reaching its eutectic concentration before freezing. Numerical simulations considering several salts (NaCl, CaCl2, MgSO4), and a range of heat fluxes (20 - 100 mW/m2) covering the range of estimated present day heat flux (20 to 40 mW/m2) to moderately elevated conditions (60 to 100 mW/m2) such as might exist in the vicinity of volcanoes and craters, all indicate the same qualitative behavior. A completely liquid, convective regime occurs at depth, overlain by a partially frozen "mushy" layer (but still convecting despite the increased viscosity), overlain by a thin frozen layer at the surface. The thicknesses of these layers depend on the heat flux, surface temperature and the salt. As heat flux increases, the mushy region

  3. Lawrence Livermore National Laboratory Surface Water Protection: A Watershed Approach

    Energy Technology Data Exchange (ETDEWEB)

    Coty, J

    2009-03-16

    This surface water protection plan (plan) provides an overview of the management efforts implemented at Lawrence Livermore National Laboratory (LLNL) that support a watershed approach to protect surface water. This plan fulfills a requirement in the Department of Energy (DOE) Order 450.1A to demonstrate a watershed approach for surface water protection that protects the environment and public health. This plan describes the use of a watershed approach within which the Laboratory's current surface water management and protections efforts have been structured and coordinated. With more than 800 million acres of land in the U.S. under federal management and stewardship, a unified approach across agencies provides enhanced resource protection and cost-effectiveness. The DOE adopted, along with other federal agencies, the Unified Federal Policy for a Watershed Approach to Federal Land and Resource Management (UFP) with a goal to protect water quality and aquatic ecosystems on federal lands. This policy intends to prevent and/or reduce water pollution from federal activities while fostering a cost-effective watershed approach to federal land and resource management. The UFP also intends to enhance the implementation of existing laws (e.g., the Clean Water Act [CWA] and National Environmental Policy Act [NEPA]) and regulations. In addition, this provides an opportunity for the federal government to serve as a model for water quality stewardship using a watershed approach for federal land and resource activities that potentially impact surface water and its uses. As a federal land manager, the Laboratory is responsible for a small but important part of those 800 million acres of land. Diverse land uses are required to support the Laboratory's mission and provide an appropriate work environment for its staff. The Laboratory comprises two sites: its main site in Livermore, California, and the Experimental Test Site (Site 300), near Tracy, California. The main site

  4. Impact of Water Recovery from Wastes on the Lunar Surface Mission Water Balance

    Science.gov (United States)

    Fisher, John W.; Hogan, John Andrew; Wignarajah, Kanapathipi; Pace, Gregory S.

    2010-01-01

    Future extended lunar surface missions will require extensive recovery of resources to reduce mission costs and enable self-sufficiency. Water is of particular importance due to its potential use for human consumption and hygiene, general cleaning, clothes washing, radiation shielding, cooling for extravehicular activity suits, and oxygen and hydrogen production. Various water sources are inherently present or are generated in lunar surface missions, and subject to recovery. They include: initial water stores, water contained in food, human and other solid wastes, wastewaters and associated brines, ISRU water, and scavenging from residual propellant in landers. This paper presents the results of an analysis of the contribution of water recovery from life support wastes on the overall water balance for lunar surface missions. Water in human wastes, metabolic activity and survival needs are well characterized and dependable figures are available. A detailed life support waste model was developed that summarizes the composition of life support wastes and their water content. Waste processing technologies were reviewed for their potential to recover that water. The recoverable water in waste is a significant contribution to the overall water balance. The value of this contribution is discussed in the context of the other major sources and loses of water. Combined with other analyses these results provide guidance for research and technology development and down-selection.

  5. The significant surface-water connectivity of "geographically isolated wetlands"

    Science.gov (United States)

    Calhoun, Aram J. K.; Mushet, David M.; Alexander, Laurie C.; DeKeyser, Edward S.; Fowler, Laurie; Lane, Charles R.; Lang, Megan W.; Rains, Mark C.; Richter, Stephen; Walls, Susan

    2017-01-01

    We evaluated the current literature, coupled with our collective research expertise, on surface-water connectivity of wetlands considered to be “geographically isolated” (sensu Tiner Wetlands 23:494–516, 2003a) to critically assess the scientific foundation of grouping wetlands based on the singular condition of being surrounded by uplands. The most recent research on wetlands considered to be “geographically isolated” shows the difficulties in grouping an ecological resource that does not reliably indicate lack of surface water connectivity in order to meet legal, regulatory, or scientific needs. Additionally, the practice of identifying “geographically isolated wetlands” based on distance from a stream can result in gross overestimates of the number of wetlands lacking ecologically important surface-water connections. Our findings do not support use of the overly simplistic label of “geographically isolated wetlands”. Wetlands surrounded by uplands vary in function and surface-water connections based on wetland landscape setting, context, climate, and geographic region and should be evaluated as such. We found that the “geographically isolated” grouping does not reflect our understanding of the hydrologic variability of these wetlands and hence does not benefit conservation of the Nation’s diverse wetland resources. Therefore, we strongly discourage use of categorizations that provide overly simplistic views of surface-water connectivity of wetlands fully embedded in upland landscapes.

  6. Properties of water surface discharge at different pulse repetition rates

    Energy Technology Data Exchange (ETDEWEB)

    Ruma,; Yoshihara, K. [Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan); Hosseini, S. H. R., E-mail: hosseini@kumamoto-u.ac.jp; Sakugawa, T.; Akiyama, H. [Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan); Institute of Pulsed Power Science, Kumamoto University, Kumamoto 860-8555 (Japan); Akiyama, M. [Department of Electrical and Electronic Engineering, Kagoshima University, Kagoshima 890-0065 (Japan); Lukeš, P. [Institute of Plasma Physics, AS CR, Prague, Prague 18200 (Czech Republic)

    2014-09-28

    The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H₂O₂) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H₂O₂ and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

  7. Generalized Potentiometric Surface of the Arikaree Aquifer, Pine Ridge Indian Reservation and Bennett County, South Dakota

    Science.gov (United States)

    Carter, Janet M.; Heakin, Allen J.

    2007-01-01

    INTRODUCTION The Pine Ridge Indian Reservation and Bennett County are located in southwest South Dakota. The Pine Ridge Indian Reservation includes all of Shannon County and the part of Jackson County south of the White River. Extensive Indian trust lands are in Bennett County. For purposes of this map, the Pine Ridge Indian Reservation and all of Bennett County are included in the study area (sheet 1). Ground water from wells and springs is the predominant source of public and domestic supply within the study area. The Arikaree aquifer is the largest source of ground water throughout this area. The Oglala Sioux Tribe is developing a ground-water management plan designed to ?preserve, protect and maintain the quality of ground water for living and future members and non-members of the Oglala Sioux Indian Tribe within the internal and external boundaries of the Pine Ridge Reservation? (Michael Catches Enemy, Oglala Sioux Tribe Natural Resources Regulatory Agency, oral commun., 2007). Hydrologic information about the Arikaree aquifer is important to managing this resource. In 1998, the U.S. Geological Survey (USGS) began working in cooperation with the Oglala Sioux Tribe to develop a potentiometric map of the Arikaree aquifer in Jackson and Shannon Counties, with a primary component of that effort being a well inventory in those counties. In 2003, the study area was expanded to include Bennett County.

  8. Operational Surface Water Detection and Monitoring Using Radarsat 2

    Directory of Open Access Journals (Sweden)

    Sandra Bolanos

    2016-03-01

    Full Text Available Traditional on-site methods for mapping and monitoring surface water extent are prohibitively expensive at a national scale within Canada. Despite successful cost-sharing programs between the provinces and the federal government, an extensive number of water features within the country remain unmonitored. Particularly difficult to monitor are the potholes in the Canadian Prairie region, most of which are ephemeral in nature and represent a discontinuous flow that influences water pathways, runoff response, flooding and local weather. Radarsat-2 and the Radarsat Constellation Mission (RCM offer unique capabilities to map the extent of water bodies at a national scale, including unmonitored sites, and leverage the current infrastructure of the Meteorological Service of Canada to monitor water information in remote regions. An analysis of the technical requirements of the Radarsat-2 beam mode, polarization and resolution is presented. A threshold-based procedure to map locations of non-vegetated water bodies after the ice break-up is used and complemented with a texture-based indicator to capture the most homogeneous water areas and automatically delineate their extents. Some strategies to cope with the radiometric artifacts of noise inherent to Synthetic Aperture Radar (SAR images are also discussed. Our results show that Radarsat-2 Fine mode can capture 88% of the total water area in a fully automated way. This will greatly improve current operational procedures for surface water monitoring information and impact a number of applications including weather forecasting, hydrological modeling, and drought/flood predictions.

  9. 3D point cloud data from laser scanning along the 2014 South Napa Earthquake surface rupture, California, USA

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Point cloud data collected along a 500 meter portion of the 2014 South Napa Earthquake surface rupture near Cuttings Wharf Road, Napa, CA, USA. The data include 7...

  10. Relationship between surface, free tropospheric and total column ozone in 2 contrasting areas in South-Africa

    CSIR Research Space (South Africa)

    Combrink, J

    1995-04-01

    Full Text Available Measurements of surface ozone in two contrasting areas of South Africa are compared with free tropospheric and Total Ozone Mapping Spectrometer (TOMS) total column ozone data. Cape Point is representative of a background monitoring station which...

  11. Linking Satellite Derived Land Surface Temperature with Cholera: A Case Study for South Sudan

    Science.gov (United States)

    Aldaach, H. S. V.; Jutla, A.; Akanda, A. S.; Colwell, R. R.

    2014-12-01

    A sudden onset of cholera in South Sudan, in April 2014 in Northern Bari in Juba town resulted in more than 400 cholera cases after four weeks of initial outbreak with a case of fatality rate of CFR 5.4%. The total number of reported cholera cases for the period of April to July, 2014 were 5,141 including 114 deaths. With the limited efficacy of cholera vaccines, it is necessary to develop mechanisms to predict cholera occurrence and thereafter devise intervention strategies for mitigating impacts of the disease. Hydroclimatic processes, primarily precipitation and air temperature are related to epidemic and episodic outbreak of cholera. However, due to coarse resolution of both datasets, it is not possible to precisely locate the geographical location of disease. Here, using Land Surface Temperature (LST) from MODIS sensors, we have developed an algorithm to identify regions susceptible for cholera. Conditions for occurrence of cholera were detectable at least one month in advance in South Sudan and were statistically sensitive to hydroclimatic anomalies of land surface and air temperature, and precipitation. Our results indicate significant spatial and temporal averaging required to infer usable information from LST over South Sudan. Preliminary results that geographically location of cholera outbreak was identifiable within 1km resolution of the LST data.

  12. Corresponding Relation between Warm Season Precipitation Extremes and Surface Air Temperature in South China

    Institute of Scientific and Technical Information of China (English)

    SUN; Wei; LI; Jian; YU; Ru-Cong

    2013-01-01

    Hourly data of 42 rain gauges over South China during 1966–2005 were used to analyze the corresponding relation between precipitation extremes and surface air temperature in the warm season(May to October).The results show that below 25℃,both daily and hourly precipitation extremes in South China increase with rising temperature.More extreme events transit to the two-time Clausius-Clapeyron(CC)relationship at lower temperatures.Daily as well as hourly precipitation extremes have a decreasing tendency nearly above 25℃,among which the decrease of hourly extremes is much more significant.In order to investigate the efects of rainfall durations,hourly precipitation extremes are presented by short duration and long duration precipitation,respectively.Results show that the dramatic decrease of hourly rainfall intensities above 25℃ is mainly caused by short duration precipitation,and long duration precipitation extremes rarely occur in South China when surface air temperature surpasses 28℃.

  13. The State and Water Resources Development through the Lens of History: A South African Case Study

    Directory of Open Access Journals (Sweden)

    Larry A. Swatuk

    2010-10-01

    Full Text Available This article sets contemporary challenges to good water governance in South Africa within an important historical context. While it is correct to say that 'the world water crisis is a crisis of governance', it is problematic to assume that all states can follow a similar path toward environmentally sustainable, economically efficient and socially equitable water resources governance and management. The nexus of decision-making power varies within and beyond states, and over time. Gramsci (1971 describes this as the "constellation of social forces". Where this constellation of social forces achieves consensus, a 'historic bloc' is said to emerge giving rise to a particular state form. The South African state form has varied greatly over several centuries, giving rise to various historic blocs. The resulting body of laws and policies and the varied forms of infrastructure that were developed to harness water for multiple social practices over time constitute a complex political ecological terrain not easily amenable to oversimplified frameworks for good water governance. This article outlines the role of water in the history of South Africa’s multiple state forms. It shows that over time, water policy, law and institutions came to reflect the increasingly complex needs of multiple actors (agriculture, mining, industry, cities, the newly enfranchised represented by different state forms and their characteristic political regimes: the Dutch East India Company; the British Empire; the Union of South Africa; the apartheid and post-apartheid republics. Authoritarian, semi-authoritarian and democratic state forms have all used central-state power to serve particular interests. Through time, this constellation of social forces has widened until, today, the state has taken upon itself the task of providing "some water for all forever" (slogan of the Department of Water Affairs. As this article suggests, despite the difficult challenges presented by a

  14. Studying surface water balance in Kurdistan province using GIS

    Directory of Open Access Journals (Sweden)

    Nader Fallah

    2016-06-01

    Full Text Available The study of water exchange in a region or area, which emphasizes the principle of conservation of matter in the water cycle, is called balance. Investigating their balance is the basis for managing the rivers’ water management, the results of which refer to the change rate in surface water supply and can efficiently be used in decision making and optimal use of water resources. The present study was carried out in order to investigate the surface water balance in Kurdistan province using GIS. In so doing, digital topographic maps, soil map of the area, and meteorological data retrieved from the regional stations were used to prepare layers of precipitation, evaporation and infiltration of rainwater into the soil. Discharge-arearegion comparative method was employed to measure the amount of runoff and base flow for each sub-basin in raster form saved per unit area which was subsequently overlapped based on balance equation, and the balance of the region was displayed in a graphical mode. The results indicated that more surface water is wasted in the southeast and central area of the province.

  15. Spatial development of the wind-driven water surface flow

    Science.gov (United States)

    Chemin, Rémi; Caulliez, Guillemette

    2015-04-01

    The water velocity field induced by wind and waves beneath an air-water interface is investigated experimentally versus fetch in the large Marseille-Luminy wind wave tank. Measurements of the vertical velocity profiles inside the subsurface shear layer were performed by a three-component Nortek acoustic Doppler velocimeter. The surface drift current was also derived from visualizations of small floating drifters recorded by a video camera looking vertically from above the water surface. Surface wave height and slopes were determined simultaneously by means of capacitance gauges and a single-point laser slope system located in the immediate vicinity of the profiler. Observations were made at steady low to moderate wind speeds and various fetches ranging between 1 and 15 meters. This study first corroborates that the thin subsurface water boundary layer forced by wind at the leading edge of the water sheet is laminar. The surface drift current velocity indeed increases gradually with fetch, following a 1/3 power law characteristic of an accelerated flat-plate laminar boundary layer. The laminar-turbulent transition manifests itself by a sudden decrease in the water surface flow velocity and a rapid deepening of the boundary layer due to the development of large-scale longitudinal vortices. Further downstream, when characteristic capillary-gravity wind waves develop at the surface, the water flow velocity increases again rapidly within a sublayer of typically 4 mm depth. This phenomenon is explained by the occurrence of an intense momentum flux from waves to the mean flow due to the dissipation of parasitic capillaries generated ahead of the dominant wave crests. This phenomenon also sustains significant small-scale turbulent motions within the whole boundary layer. However, when gravity-capillary waves of length longer than 10 cm then grow at the water surface, the mean flow velocity field decreases drastically over the whole boundary layer thickness. At the same

  16. Influence of building resolution on surface water inundation outputs

    Science.gov (United States)

    Green, Daniel; Yu, Dapeng; Pattison, Ian

    2016-04-01

    Surface water (pluvial) flooding occurs when intense precipitation events overwhelm the drainage capacity of an area and excess water is unable to infiltrate into the ground or drain via natural or artificial drainage channels. In the UK, over 3 million properties are at risk from surface water flooding alone, accounting for approximately one third of all UK flood risk. This risk is predicted to increase due to future climatic changes resulting in an increasing magnitude and frequency of intense precipitation events. Numerical modelling is a well-established method of investigating surface water flood risk, allowing the researcher to gain an understanding of the depth, extent and severity of actual or hypothetical flood scenarios. Although numerical models allow the simulation of surface water inundation in a particular region, the model parameters (e.g. roughness, hydraulic conductivity) and resolution of topographic data have been shown to exert a profound influence on the inundation outputs which often leads to an over- or under-estimation of flood depths and extent without the use of external validation data to calibrate model outputs. Although previous research has demonstrated that model outputs are highly sensitive to Digital Elevation Model (DEM) mesh resolution, with flood inundation over large and complex topographies often requiring mesh resolutions coarser than the structural features (e.g. buildings) present within the study catchment, the specific influence of building resolution on surface flowpaths and connectivity during a surface water flood event has not been investigated. In this study, a LiDAR-derived DEM and OS MasterMap buildings layer of the Loughborough University campus, UK, were rasterized into separate 1m, 5m and 10m resolution layers. These layers were combined to create a series of Digital Surface Models (DSM) with varying, mismatching building and DEM resolutions (e.g. 1m DEM resolution, 10m building resolution, etc.) to understand

  17. Domestic rainwater harvesting to improve water supply in rural South Africa

    Science.gov (United States)

    Mwenge Kahinda, Jean-marc; Taigbenu, Akpofure E.; Boroto, Jean R.

    Halving the proportion of people without sustainable access to safe drinking water and basic sanitation, is one of the targets of the 7th Millennium Development Goals (MDGs). In South Africa, with its mix of developed and developing regions, 9.7 million (20%) of the people do not have access to adequate water supply and 16 million (33%) lack proper sanitation services. Domestic Rainwater Harvesting (DRWH), which provides water directly to households enables a number of small-scale productive activities, has the potential to supply water even in rural and peri-urban areas that conventional technologies cannot supply. As part of the effort to achieve the MDGs, the South African government has committed itself to provide financial assistance to poor households for the capital cost of rainwater storage tanks and related works in the rural areas. Despite this financial assistance, the legal status of DRWH remains unclear and DRWH is in fact illegal by strict application of the water legislations. Beyond the cost of installation, maintenance and proper use of the DRWH system to ensure its sustainability, there is risk of waterborne diseases. This paper explores challenges to sustainable implementation of DRWH and proposes some interventions which the South African government could implement to overcome them.

  18. Foreign trade and pollution: the case of South China water quality

    Science.gov (United States)

    Zuo, Hui; Ai, Danxiang; Lin, Yuling

    2017-01-01

    With rapid economic growth, South China has to face the most serious water pollution. However, whether or not such kind of water pollution is mainly caused by foreign trade is questionable. And, how the trade mode will be changed by pollution and corresponding regulation is also uncertain. In this paper, a fully endogenous model, which integrate economic growth, energy use and pollution, is designed to interpret the interrelation among these key variables in South China. Through this model, a new possibility of water environment Kuznets curve change has been investigated. Attribute to mixed two stage feasible general least square estimation method, we conclude that foreign trade has strong influence on environment change rate and the turning point. It can make the virtuous circle of between economic growth and environment improvement come early or later in different circumstances. Export and import play different role in such process and have counter effects on environment.

  19. Geochemistry of hydropressured brines in South Louisiana: potential for reaction with injected geopressured waste waters

    Energy Technology Data Exchange (ETDEWEB)

    Hanor, J.S.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    Hydropressured, saline-water sands are being considered as possible sites for the disposal of geopressured-geothermal waste waters in South Louisiana. Probable injection horizons would most likely contain native brines of 120 to 140 g/l TDS. These brines show wide ranges in concentration of dissolved Ca, Sr, Ba, Fe, SO/sub 4/, and HCO/sub 3/, even within a restricted range of salinities. The probability is high that mineral precipitation will occur if untreated geopressured wastes are mixed with these waters. Clay migration and additional plugging of the injection well is possible if the injected wastes are significantly less saline than the native fluids. Costs of site-specific geochemical evaluation and chemical pre-treatment are thus factors which must be considered in the economic evaluation of deep well disposal of geopressured wastes in South Louisiana.

  20. Infiltration of pesticides in surface water into nearby drinking water supply wells

    Science.gov (United States)

    Malaguerra, F.; Albrechtsen, H.; Binning, P. J.

    2010-12-01

    Drinking water wells are often placed near streams because streams often overly permeable sediments and the water table is near the surface in valleys, and so pumping costs are reduced. The lowering of the water table by pumping wells can reverse the natural flow from the groundwater to the stream, inducing infiltration of surface water to groundwater and consequently to the drinking water well. Many attenuation processes can take place in the riparian zone, mainly due to mixing, biodegradation and sorption. However, if the water travel time from the surface water to the pumping well is too short, or if the compounds are poorly degradable, contaminants can reach the drinking water well at high concentrations, jeopardizing drinking water quality. Here we developed a reactive transport model to evaluate the risk of contamination of drinking water wells by surface water pollution. The model was validated using data of a tracer experiment in a riparian zone. Three compounds were considered: an older pesticide MCPP (Mecoprop) which is mobile and persistent, glyphosate (Roundup), a new biodegradable and strongly sorbed pesticide, and its degradation product AMPA. Global sensitivity analysis using the method of Morris was employed to identify the dominant model parameters. Results showed that the presence of an aquitard and its characteristics (degree of fracturing and thickness), pollutant properties and well depth are the crucial factors affecting the risk of drinking water well contamination from surface water. Global sensitivity analysis results were compared with rank correlation statistics between pesticide concentrations and geological parameters derived from a comprehensive database of Danish drinking water wells. Aquitard thickness and well depth are the most critical parameters in both the model and observed data.

  1. Return of naturally sourced Pb to Atlantic surface waters

    Science.gov (United States)

    Bridgestock, Luke; van de Flierdt, Tina; Rehkämper, Mark; Paul, Maxence; Middag, Rob; Milne, Angela; Lohan, Maeve C.; Baker, Alex R.; Chance, Rosie; Khondoker, Roulin; Strekopytov, Stanislav; Humphreys-Williams, Emma; Achterberg, Eric P.; Rijkenberg, Micha J. A.; Gerringa, Loes J. A.; de Baar, Hein J. W.

    2016-09-01

    Anthropogenic emissions completely overwhelmed natural marine lead (Pb) sources during the past century, predominantly due to leaded petrol usage. Here, based on Pb isotope measurements, we reassess the importance of natural and anthropogenic Pb sources to the tropical North Atlantic following the nearly complete global cessation of leaded petrol use. Significant proportions of up to 30-50% of natural Pb, derived from mineral dust, are observed in Atlantic surface waters, reflecting the success of the global effort to reduce anthropogenic Pb emissions. The observation of mineral dust derived Pb in surface waters is governed by the elevated atmospheric mineral dust concentration of the North African dust plume and the dominance of dry deposition for the atmospheric aerosol flux to surface waters. Given these specific regional conditions, emissions from anthropogenic activities will remain the dominant global marine Pb source, even in the absence of leaded petrol combustion.

  2. Macroelements in the surface microlayer of water of urban ponds

    Directory of Open Access Journals (Sweden)

    Antonowicz Józef Piotr

    2016-03-01

    Full Text Available Analyses were conducted concerning the accumulation of four metals representing the group of macroelements, i.e. sodium, potassium, calcium and magnesium in two ponds located in the city of Słupsk. Water samples for chemical analyses were collected from the surface microlayer using a Garrett net. At the same time subsurface water samples were collected. Concentrations of metals were determined using a mass spectrometer. Generally, amounts of sodium, potassium, calcium and magnesium were similar in surface microlayer and subsurface water. Only in the case of potassium and calcium was low enrichment observed in the surface microlayer in one pond, while the greatest extent for magnesium enrichment was observed in the spring period.

  3. Occurrence of illicit drugs in surface waters in China.

    Science.gov (United States)

    Li, Kaiyang; Du, Peng; Xu, Zeqiong; Gao, Tingting; Li, Xiqing

    2016-06-01

    Illicit drugs have been recognized as a group of emerging contaminants. In this work, occurrence of common illicit drugs and their metabolites in Chinese surface waters was examined by collecting samples from 49 lakes and 4 major rivers across the country. Among the drugs examined, methamphetamine and ketamine were detected with highest frequencies and concentration levels, consistent with the fact that these are primary drugs of abuse in China. Detection frequencies and concentrations of other drugs were much lower than in European lakes and rivers reported in the literature. In most Chinese surface waters methamphetamine and ketamine were detected at concentrations of several ng L(-1) or less, but in some southern lakes and rivers, these two drugs were detected at much higher concentrations (up to several tens ng L(-1)). Greater occurrence of methamphetamine and ketamine in southern surface waters was attributed to greater abuse and more clandestine production of the two drugs in southern China.

  4. Wavefront modulation of water surface wave by a metasurface

    Institute of Scientific and Technical Information of China (English)

    孙海涛; 程营; 王敬时; 刘晓峻

    2015-01-01

    We design a planar metasurface to modulate the wavefront of a water surface wave (WSW) on a deep sub-wavelength scale. The metasurface is composed of an array of coiling-up-space units with specially designed parameters, and can take on the work of steering the wavefront when it is pierced into water. Like their acoustic counterparts, the modulation of WSW is ascribed to the gradient phase shift of the coiling-up-space units, which can be perfectly tuned by changing the coiling plate length and channel number inside the units. According to the generalized Snell’s law, negative refraction and‘driven’ surface mode of WSW are also demonstrated at certain incidences. Specially, the transmitted WSW could be efficiently guided out by linking a symmetrically-corrugated channel in‘driven’ surface mode. This work may have potential applications in water wave energy extraction and coastal protection.

  5. Predicting Fire Season Severity in South America Using Sea Surface Temperature Anomalies

    Science.gov (United States)

    Chen, Yang; Randerson, James T.; Morton, Douglas C.; Jin, Yufang; DeFries, Ruth S.; Collatz, George J.; Kasibhatla, Prasad S.; Giglio, Louis; Jin, Yufang; Marlier, Miriam

    2011-01-01

    Fires in South America cause forest degradation and contribute to carbon emissions associated with land use change. Here we investigated the relationship between year-to-year changes in satellite-derived estimates of fire activity in South America and sea surface temperature (SST) anomalies. We found that the Oceanic Ni o Index (ONI) was correlated with interannual fire activity in the eastern Amazon whereas the Atlantic Multidecadal Oscillation (AMO) index was more closely linked with fires in the southern and southwestern Amazon. Combining these two climate indices, we developed an empirical model that predicted regional annual fire season severity (FSS) with 3-5 month lead times. Our approach provides the foundation for an early warning system for forecasting the vulnerability of Amazon forests to fires, thus enabling more effective management with benefits for mitigation of greenhouse gas and air pollutant emissions.

  6. Forecasting Fire Season Severity in South America Using Sea Surface Temperature Anomalies

    Science.gov (United States)

    Chen, Yang; Randerson, James T.; Morton, Douglas C.; DeFries, Ruth S.; Collatz, G. James; Kasibhatla, Prasad S.; Giglio, Louis; Jin, Yufang; Marlier, Miriam E.

    2011-01-01

    Fires in South America cause forest degradation and contribute to carbon emissions associated with land use change. We investigated the relationship between year-to-year changes in fire activity in South America and sea surface temperatures. We found that the Oceanic Ni o Index was correlated with interannual fire activity in the eastern Amazon, whereas the Atlantic Multidecadal Oscillation index was more closely linked with fires in the southern and southwestern Amazon. Combining these two climate indices, we developed an empirical model to forecast regional fire season severity with lead times of 3 to 5 months. Our approach may contribute to the development of an early warning system for anticipating the vulnerability of Amazon forests to fires, thus enabling more effective management with benefits for climate and air quality.

  7. Forecasting Fire Season Severity in South America Using Sea Surface Temperature Anomalies

    Science.gov (United States)

    Chen, Yang; Randerson, James T.; Morton, Douglas C.; DeFries, Ruth S.; Collatz, G. James; Kasibhatla, Prasad S.; Giglio, Louis; Jin, Yufang; Marlier, Miriam E.

    2011-01-01

    Fires in South America cause forest degradation and contribute to carbon emissions associated with land use change. We investigated the relationship between year-to-year changes in fire activity in South America and sea surface temperatures. We found that the Oceanic Ni o Index was correlated with interannual fire activity in the eastern Amazon, whereas the Atlantic Multidecadal Oscillation index was more closely linked with fires in the southern and southwestern Amazon. Combining these two climate indices, we developed an empirical model to forecast regional fire season severity with lead times of 3 to 5 months. Our approach may contribute to the development of an early warning system for anticipating the vulnerability of Amazon forests to fires, thus enabling more effective management with benefits for climate and air quality.

  8. Salty glycerol versus salty water surface organization: bromide and iodide surface propensities.

    Science.gov (United States)

    Huang, Zishuai; Hua, Wei; Verreault, Dominique; Allen, Heather C

    2013-07-25

    Salty NaBr and NaI glycerol solution interfaces are examined in the OH stretching region using broadband vibrational sum frequency generation (VSFG) spectroscopy. Raman and infrared (IR) spectroscopy are used to further understand the VSFG spectroscopic signature. The VSFG spectra of salty glycerol solutions reveal that bromide and iodide anions perturb the interfacial glycerol organization in a manner similar as that found in aqueous halide salt solutions, thus confirming the presence of bromide and iodide anions at the glycerol surface. Surface tension measurements are consistent with the surface propensity suggested by the VSFG data and also show that the surface excess increases with increasing salt concentration, similar to that of water. In addition, iodide is shown to have more surface prevalence than bromide, as has also been determined from aqueous solutions. These results suggest that glycerol behaves similarly to water with respect to surface activity and solvation of halide anions at its air/liquid interface.

  9. Water stress indices for the sugarcane crop on different irrigated surfaces

    Directory of Open Access Journals (Sweden)

    Rodrigo G. Brunini

    Full Text Available ABSTRACT Sugarcane (Saccharum officinarum L. is a crop of vital importance to Brazil, in the production of sugar and ethanol, power generation and raw materials for various purposes. Strategic information such as topography and canopy temperature can provide management technologies accessible to farmers. The objective of this study was to determine water stress indices for sugarcane in irrigated areas, with different exposures and slopes. The daily water stress index of the plants and the water potential in the soil were evaluated and the production system was analyzed. The experiment was carried out in an “Experimental Watershed”, using six surfaces, two horizontal and the other ones with 20 and 40% North and South exposure slopes. Water stress level was determined by measuring the temperatures of the vegetation cover and the ambient air. Watering was carried out using a drip irrigation system. The results showed that water stress index of sugarcane varies according to exposure and slope of the terrain, while areas whose water stress index was above 5.0 oC had lower yield values.

  10. Determination of the water quality index ratings of water in the Mpumalanga and North West provinces, South Africa

    Science.gov (United States)

    Wanda, Elijah M. M.; Mamba, Bhekie B.; Msagati, Titus A. M.

    2016-04-01

    This study reports on the water quality index (WQI) of wastewater and drinking water in the Mpumalanga and North West provinces of South Africa. The WQI is one of the most effective tools available to water sustainability researchers, because it provides an easily intelligible ranking of water quality on a rating scale from 0 to 100, based on the ascription of different weightings to several different parameters. In this study the WQI index ratings of wastewater and drinking water samples were computed according to the levels of pH, electrical conductivity (EC), biochemical oxygen demand (BOD), E. coli, temperature, turbidity and nutrients (nitrogen and phosphates) found in water samples collected from the two provinces between June and December, 2014. This study isolated three groups of WQ-rated waters, namely: fair (with a WQI range = 32.87-38.54%), medium (with a WQI range = 56.54-69.77%) and good (with a WQI range = 71.69-81.63%). More specifically, 23%, 23% and 54% of the sampled sites registered waters with fair, medium and good WQ ratings respectively. None of the sites sampled during the entire period of the project registered excellent or very good water quality ratings, which would ordinarily indicate that no treatment is required to make it fit for human consumption. Nevertheless, the results obtained by the Eerstehoek and Schoemansville water treatment plants in Mpumalanga and North West provinces, respectively, suggest that substantial improvement in the quality of water samples is possible, since the WQI values for all of the treated samples were higher than those for raw water. Presence of high levels of BOD, low levels of dissolved oxygen (DO), E. coli, nitrates and phosphates especially in raw water samples greatly affected their overall WQ ratings. It is recommended that a point-of-use system should be introduced to treat water intended for domestic purposes in the clean-water-deprived areas.

  11. Alternative Water Allocation in Kyrgyzstan: Lessons from the Lower Colorado River Basin and New South Wales

    Directory of Open Access Journals (Sweden)

    Nazir Mirzaev

    2010-08-01

    Full Text Available Focus group discussions and a modeling approach were applied to determine policy and regulatory refinements for current water allocation practices in Kyrgyzstan. Lessons from the Lower Colorado River basin, Texas and New South Wales, Australia were taken into consideration. The paper analyzes the impact of adopting some of these interventions within the socio-environmental context that currently prevails in Kyrgyzstan. The optimization model for water distribution at the river-basin scale was developed using GAMS 2.25 software. Application of the model to the Akbura River basin indicated efficiencies in the proposed institutional rules especially in low water years.

  12. Observation and Simulation of Meteorology and Surface Energy Components over the South China Sea in Summers of 2004 and 2006

    Directory of Open Access Journals (Sweden)

    Yung-Yao Lan

    2010-01-01

    Full Text Available Measurements of meteorological variables and surface energy components over the South China Sea (SCS are compared with the NCEP-DOE AMIP-II reanalysis (NCEP2. The observations were con ducted on a re search vessel in the summers of 2004 and 2006. In addition, a one-column ocean model is used to simulate surface energy components and upper-level water temperatures (at 4 and 10 m depths. The simulated upper-level water temperatures agree well with the observations during the two cruises (OR1-728, OR1-802 with a root-mean-square difference (RMSD smaller than 0.4 K. The observations and the simulations show that the solar radiation (with a mean of ~200 W m-2 is stronger than the la tent heat flux (~160 W m-2, and the la tent heat flux is stronger than the sensible heat flux (~10 W m-2 during both periods. None the less, the magnitude of variability in heat flux caused by the sporadic wind is not seen in the reanalysis, it appears in the turbulent heat flux simulated by the model. The major differences between the model estimate and the NCEP2 reanalysis are the value of emissivity and the inclusion of diurnal cycles in keyvariables, with the value of NCEP2 for emissivity as 1. The emissivity of this part of ocean is observed to be 0.96 with albedo at 0.07.

  13. Spring and surface water quality of the Cyprus ophiolites

    Directory of Open Access Journals (Sweden)

    C. Neal

    2002-01-01

    Full Text Available A survey of surface, spring and borehole waters associated with the ophiolite rocks of Cyprus shows five broad water types (1 Mg-HCO3, (2 Na-SO4-Cl-HCO3, (3 Na-Ca-Cl-SO4-OH-CO3, (4 Na-Cl-SO4 and (5 Ca-SO4. The waters represent a progression in chemical reactivity from surface waters that evolve within a groundwater setting due to hydrolysis of the basic/ultrabasic rock as modified by CO2-weathering. An increase in salinity is also observed which is due to mixing with a saline end-member (modified sea-water and dissolution of gypsum/anhydrite. In some cases, the waters have pH values greater than 11. Such high values are associated with low temperature serpentinisation reactions. The system is a net sink for CO2. This feature is related not only to the hydrolysis of the primary minerals in the rock, but also to CaCO3 or Ca-Mg-CO3 solubility controls. Under hyperalkaline conditions, virtually all the carbon dioxide is lost from the water due to the sufficiently high calcium levels and carbonate buffering is then insignificant. Calcium sulphate solubility controls may also be operative when calcium and sulphate concentrations are particularly high. Keywords: Cyprus, Troodos, ophiolite, serpentinisation, spring, stream, water quality, bromide, iodine, boron, trace elements, hyperalkaline.

  14. Zirconium fluoride glass - Surface crystals formed by reaction with water

    Science.gov (United States)

    Doremus, R. H.; Bansal, N. P.; Bradner, T.; Murphy, D.

    1984-01-01

    The hydrated surfaces of a zirconium barium fluoride glass, which has potential for application in optical fibers and other optical elements, were observed by scanning electron microscopy. Crystalline zirconium fluoride was identified by analysis of X-ray diffraction patterns of the surface crystals and found to be the main constituent of the surface material. It was also found that hydrated zirconium fluorides form only in highly acidic fluoride solutions. It is possible that the zirconium fluoride crystals form directly on the glass surface as a result of its depletion of other ions. The solubility of zirconium fluoride is suggested to be probably much lower than that of barium fluoride (0.16 g/100 cu cm at 18 C). Dissolution was determined to be the predominant process in the initial stages of the reaction of the glass with water. Penetration of water into the glass has little effect.

  15. Eutrophication management in surface waters using lanthanum modified bentonite

    DEFF Research Database (Denmark)

    Copetti, Diego; Finsterle, Karin; Marziali, Laura

    2016-01-01

    This paper reviews the scientific knowledge on the use of a lanthanum modified bentonite (LMB) to manage eutrophication in surface water. The LMB has been applied in around 200 environments worldwide and it has undergone extensive testing at laboratory, mesocosm, and whole lake scales. The availa......This paper reviews the scientific knowledge on the use of a lanthanum modified bentonite (LMB) to manage eutrophication in surface water. The LMB has been applied in around 200 environments worldwide and it has undergone extensive testing at laboratory, mesocosm, and whole lake scales...

  16. Evaluation of ATP measurements to detect microbial ingress by wastewater and surface water in drinking water

    DEFF Research Database (Denmark)

    Vang, Óluva Karin; Corfitzen, Charlotte B.; Smith, Christian

    2014-01-01

    in this respect. Compared to traditional microbiological methods, the ATP assay could detect wastewater and surface water in drinking water to a higher degree than total direct counts (TDCs), while both heterotrophic plate counts (HPC 22 °C and HPC 37 °C) and Colilert-18 (Escherichia coli and coliforms) were more......Fast and reliable methods are required for monitoring of microbial drinking water quality in order to protect public health. Adenosine triphosphate (ATP) was investigated as a potential real-time parameter for detecting microbial ingress in drinking water contaminated with wastewater or surface...

  17. Some Aspects of Surface Water Treatment Technology in Tirana Drinking Water Treatment Plant

    OpenAIRE

    , Tania Floqi; , Aleksandër Trajçe; , Daut Vezi

    2009-01-01

    Tirana’s Bovilla treatment plant was the Şrst of its kind for Albania, which treats surface water. The input water comes from the Bovilla artiŞcial lake, around which, the presence of villages induces pollution in the surface water and therefore affects the efŞciency of treatment plant and consequently the quality of drinking water. The treatment plant is a simple conventional system and includes pre-oxidation, coagulation, şocculation & sedimentation, fast Şltration, post-oxidation. ...

  18. Influence of ENSO and IOD to Variability of Sea Surface Height in the North and South of Java Island

    Science.gov (United States)

    Fadlan, Ahmad; Nugroho Sugianto, Denny; Kunarso; Zainuri, Muhammad

    2017-02-01

    Indonesia is one of the largest archipelagic countries in the world. Besides being in the tropics, these waters are also located between two continents and two oceans that making this area are heavily influenced by the global atmospheric phenomena such as El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). Sea level rise is one of the main threats faced by Indonesia and other island countries in the world. Not only global warming, sea level rise in the tropics also caused by inter annual variability such as ENSO and IOD. This research has been aimed to determine the influence of ENSO and IOD to variability of sea surface height in the north and south of Java. This research used Satellite altimetry data were constructed by multi-mission satellite. These results showed that the sea level anomaly generally inversely related to ENSO and Dipole Mode Index. The phenomenon that most influence a decrease sea level anomaly in the study area is a phenomenon IOD + and the phenomenon that most influenced the increase sea level anomaly is La Niña. South of Java is area that has the large effect of changes in sea levels than north of Java. During La Niña, sea level anomaly can be increase up to 0.3 m and sea level anomaly can be decrease up to -0.28 m during IOD+.

  19. Fluctuations of water near extended hydrophobic and hydrophilic surfaces

    OpenAIRE

    Patel, Amish J.; Chandler, David

    2009-01-01

    We use molecular dynamics simulations of the SPC-E model of liquid water to derive probability distributions for water density fluctuations in probe volumes of different shapes and sizes, both in the bulk as well as near hydrophobic and hydrophilic surfaces. To obtain our results, we introduce a biased sampling of coarse-grained densities, which in turn biases the actual solvent density. The technique is easily combined with molecular dynamics integration algorithms. Our principal result is t...

  20. Ground-water resources of the South Platte River Basin in western Adams and southwestern Weld Counties, Colorado

    Science.gov (United States)

    Smith, Rex O.; Schneider, P.A.; Petri, Lester R.

    1964-01-01

    The area described in this report consists of about 970 square miles in western Adams and southwestern Weld Counties in northeastern Colorado. It includes that part of the South Platte River valley between Denver and Kuner, Colo., all of Beebe Draw, and the lower part of the valley of Box Elder Creek. The stream-valley lowlands are separated by rolling uplands. The climate is semiarid, the normal annual precipitation being about 13 inches; thus, irrigation is essential for stable agricultural development. The area contains about 220,000 acres of irrigated land in the stream valleys. Most of the remaining 400,000 acres of land is used for dry farming or grazing because it lacks irrigation water. Most of the lowlands were brought under irrigation with surface water during the early 1900's, and now nearly all the surface water in the area is appropriated for irrigation within and downstream from the area. Because the natural flow of the streams is sometimes less than the demand for water, ground water is used to supplement the surface-water supply. Wells, drilled chiefly since 1930, supply the supplemental water and in some places are the sole supply for irrigation use. Rocks exposed in the area are of sedimentary origin and range in age from Lato Cretaceous to Recent. Those that are consolidated, called 'bedrock' in this report, consist of the Fox Hills sandstone and the Laramie and Arapahoe formations, all of Late Cretaceous age, and the Denver formation and Dawson arkose of Late Cretaceous and Tertiary age. The surface of the bedrock was shaped by ancestral streams, the valleys of which are reflected by the present surface topography. Dune sand, slope wash, and thin upland deposits of Quaternary age mantle the bedrock in the divide areas, and stream deposits ranging in thickness from 0 to about 125 feet partly fill the ancestral valleys. The valley-fill deposits consist of beds and lenses of clay, silt, sand, gravel, cobbles, and boulders. Abundant supplies of

  1. Surface and subsurface microgravity data in the vicinity of Sanford Underground Research Facility, Lead, South Dakota

    Science.gov (United States)

    Kennedy, Jeffrey R.; Koth, Karl R.; Carruth, Rob

    2015-01-01

    Absolute gravity data were collected at 32 stations in the vicinity of the Sanford Underground Research Facility from 2007 through 2014 for the purpose of monitoring groundwater storage change during dewatering of the former Homestake gold mine in the Black Hills of South Dakota, the largest and deepest underground mine in North America. Eight underground stations are at depths from 300 feet below land surface to 4,850 feet below land surface. Surface stations were located using Global Positioning System observations, and subsurface stations were located on the basis of maps constructed from survey measurements made while the mine was in operation. Gravity varies widely at many stations; however, no consistent temporal trends are present across all stations during the 7-year period of data collection.

  2. Antibiotic resistance, efflux pump genes and virulence determinants in Enterococcus spp. from surface water systems.

    Science.gov (United States)

    Molale, L G; Bezuidenhout, Cornelius Carlos

    2016-11-01

    The aim of this study was to report on antibiotic susceptibility patterns as well as highlight the presence of efflux pump genes and virulence genetic determinants in Enterococcus spp. isolated from South African surface water systems. One hundred and twenty-four Enterococcus isolates consisting of seven species were identified. Antimicrobial susceptibility testing revealed a high percentage of isolates was resistant to β-lactams and vancomycin. Many were also resistant to other antibiotic groups. These isolates were screened by PCR, for the presence of four efflux pump genes (mefA, tetK, tetL and msrC). Efflux genes mefA and tetK were not detected in any of the Enterococcus spp. However, tetL and msrC were detected in 17 % of the Enterococcus spp. The presence of virulence factors in the Enterococcus spp. harbouring efflux pump genes was determined. Virulence determinants were detected in 86 % of the Enterococcus spp. harbouring efflux pump genes. Four (asa1, cylA, gel and hyl) of the five virulence factors were detected. The findings of this study have demonstrated that Enterococcus from South African surface water systems are resistant to multiple antibiotics, some of which are frequently used for therapy. Furthermore, these isolates harbour efflux pump genes coding for resistance to antibiotics and virulence factors which enhance their pathogenic potential.

  3. Monitoring of endocrine disrupting chemicals in surface water

    CSIR Research Space (South Africa)

    Govender, S

    2008-06-01

    Full Text Available the surface. The chelated Pluronic-DMDDO ligand can be used for affinity purification of histidine tagged proteins. A regeneration formulation based on anionic SDS detergent desorbed pluronic modified polymeric membranes and the possibility of re... ingredients, household products and industrial chemicals. Surface waters are the main sink of said EDCs. Accurate EDC detection is usually via time consuming and costly ex situ LC-MS and GC-MS analysis. An important class of biosensors include those...

  4. Hydrodynamic boundary condition of water on hydrophobic surfaces.

    Science.gov (United States)

    Schaeffel, David; Yordanov, Stoyan; Schmelzeisen, Marcus; Yamamoto, Tetsuya; Kappl, Michael; Schmitz, Roman; Dünweg, Burkhard; Butt, Hans-Jürgen; Koynov, Kaloian

    2013-05-01

    By combining total internal reflection fluorescence cross-correlation spectroscopy with Brownian dynamics simulations, we were able to measure the hydrodynamic boundary condition of water flowing over a smooth solid surface with exceptional accuracy. We analyzed the flow of aqueous electrolytes over glass coated with a layer of poly(dimethylsiloxane) (advancing contact angle Θ = 108°) or perfluorosilane (Θ = 113°). Within an error of better than 10 nm the slip length was indistinguishable from zero on all surfaces.

  5. Microbiologic effectiveness of boiling and safe water storage in South Sulawesi, Indonesia.

    Science.gov (United States)

    Sodha, Samir V; Menon, M; Trivedi, K; Ati, A; Figueroa, M E; Ainslie, R; Wannemuehler, K; Quick, R

    2011-09-01

    In Indonesia, where diarrhea remains a major cause of mortality among children water. We assessed the impact of boiling on water quality in South Sulawesi. We surveyed randomly selected households with at least one child water samples for Escherichia coli contamination. Among 242 households, 96% of source and 51% of stored water samples yielded E. coli. Unboiled water samples, obtained from 15% of households, were more likely to yield E. coli than boiled samples [prevalence ratios (PR) = 2.0, 95% confidence interval (CI) 1.7-2.5]. Water stored in wide-mouthed (PR = 1.4, 95% CI = 1.1-1.8) or uncovered (PR = 1.8, 95% CI = 1.3-2.4) containers, or observed to be touched by the respondent's hands (PR = 1.6, 95% CI = 1.3-2.1) was more likely to yield E. coli. A multivariable model showed that households that did not boil water were more likely to have contaminated stored water than households that did boil water (PR = 1.9, 95% CI = 1.5-2.3). Although this study demonstrated the effectiveness of boiling in reducing contamination, overall impact on water quality was suboptimal. Future studies are needed to identify factors behind the success of boiling water in Indonesia to inform efforts to scale up other effective water treatment practices.

  6. Nanofiltration in Transforming Surface Water into Healthy Water: Comparison with Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    L. D. Naidu

    2015-01-01

    Full Text Available The natural surface water, especially available through rivers, is the main source of healthy water for the living beings throughout the world from ancient days as it consists of all essential minerals. With the advent of industrialization, gradually even the most prominent rivers have been polluted in all parts of the world. Although there are lots of technologies, nanofiltration (NF has been chosen to transform river water into healthy water due to its unique advantages of retaining optimum TDS (with essential minerals required for human body, consuming of lower energy, and no usage of any chemicals. The prominent parameters of surface water and macro/microminerals of treated water have been analyzed. It is shown that NF is better in producing healthy water with high flux by consuming low energy.

  7. Crop-specific seasonal estimates of irrigation water demand in South Asia

    Directory of Open Access Journals (Sweden)

    H. Biemans

    2015-08-01

    Full Text Available Especially in the Himalayan headwaters of the main rivers in South Asia, shifts in runoff are expected as a result of a rapidly changing climate. In recent years, our insight in these shifts and their impact on water availability has increased. However, a similar detailed understanding of the seasonal pattern in water demand is surprisingly absent. This hampers a proper assessment of water stress and ways to cope and adapt. In this study, the seasonal pattern of irrigation water demand resulting from the typical practice of multiple-cropping in South Asia was accounted for by introducing double-cropping with monsoon-dependent planting dates in a hydrology and vegetation model. Crop yields were calibrated to the latest subnational statistics of India, Pakistan, Bangladesh and Nepal. The representation of seasonal land use and more accurate cropping periods lead to lower estimates of irrigation water demand compared to previous model-based studies, despite the net irrigated area being higher. Crop irrigation water demand differs sharply between seasons and regions; in Pakistan, winter (Rabi and summer (Kharif irrigation demands are almost equal, whereas in Bangladesh the Rabi demand is ~ 100 times higher. Moreover, the relative importance of irrigation supply vs. rain decreases sharply from west to east. Given the size and importance of South Asia, improved regional estimates of food production and its irrigation water demand will also affect global estimates. In models used for global water resources and food-security assessments, processes like multiple-cropping and monsoon-dependent planting dates should not be ignored.

  8. Crop-specific seasonal estimates of irrigation-water demand in South Asia

    Science.gov (United States)

    Biemans, Hester; Siderius, Christian; Mishra, Ashok; Ahmad, Bashir

    2016-05-01

    Especially in the Himalayan headwaters of the main rivers in South Asia, shifts in runoff are expected as a result of a rapidly changing climate. In recent years, our insight into these shifts and their impact on water availability has increased. However, a similar detailed understanding of the seasonal pattern in water demand is surprisingly absent. This hampers a proper assessment of water stress and ways to cope and adapt. In this study, the seasonal pattern of irrigation-water demand resulting from the typical practice of multiple cropping in South Asia was accounted for by introducing double cropping with monsoon-dependent planting dates in a hydrology and vegetation model. Crop yields were calibrated to the latest state-level statistics of India, Pakistan, Bangladesh and Nepal. The improvements in seasonal land use and cropping periods lead to lower estimates of irrigation-water demand compared to previous model-based studies, despite the net irrigated area being higher. Crop irrigation-water demand differs sharply between seasons and regions; in Pakistan, winter (rabi) and monsoon summer (kharif) irrigation demands are almost equal, whereas in Bangladesh the rabi demand is ~ 100 times higher. Moreover, the relative importance of irrigation supply versus rain decreases sharply from west to east. Given the size and importance of South Asia improved regional estimates of food production and its irrigation-water demand will also affect global estimates. In models used for global water resources and food-security assessments, processes like multiple cropping and monsoon-dependent planting dates should not be ignored.

  9. Crop-specific seasonal estimates of irrigation water demand in South Asia

    Science.gov (United States)

    Biemans, H.; Siderius, C.; Mishra, A.; Ahmad, B.

    2015-08-01

    Especially in the Himalayan headwaters of the main rivers in South Asia, shifts in runoff are expected as a result of a rapidly changing climate. In recent years, our insight in these shifts and their impact on water availability has increased. However, a similar detailed understanding of the seasonal pattern in water demand is surprisingly absent. This hampers a proper assessment of water stress and ways to cope and adapt. In this study, the seasonal pattern of irrigation water demand resulting from the typical practice of multiple-cropping in South Asia was accounted for by introducing double-cropping with monsoon-dependent planting dates in a hydrology and vegetation model. Crop yields were calibrated to the latest subnational statistics of India, Pakistan, Bangladesh and Nepal. The representation of seasonal land use and more accurate cropping periods lead to lower estimates of irrigation water demand compared to previous model-based studies, despite the net irrigated area being higher. Crop irrigation water demand differs sharply between seasons and regions; in Pakistan, winter (Rabi) and summer (Kharif) irrigation demands are almost equal, whereas in Bangladesh the Rabi demand is ~ 100 times higher. Moreover, the relative importance of irrigation supply vs. rain decreases sharply from west to east. Given the size and importance of South Asia, improved regional estimates of food production and its irrigation water demand will also affect global estimates. In models used for global water resources and food-security assessments, processes like multiple-cropping and monsoon-dependent planting dates should not be ignored.

  10. A comparative study of the phosphate levels in some surface and ground water bodies of Swaziland

    Directory of Open Access Journals (Sweden)

    A.O. Fadiran

    2008-08-01

    Full Text Available The levels of total phosphate in selected surface water and groundwater bodies from Manzini and Lubombo regions of Swaziland were determined using UV spectroscopic method. Samples were collected from three rivers (upstream and downstream of each, three industrial effluents, one reservoir, one pond, one tap water and fifteen boreholes. Mean phosphate levels in the tap water and reservoir varied between 0.08-0.09 mg/L while for the river samples, the range was 0.11-0.37 and for the industrial discharge, it was 0.11-1.60 mg/L PO4–P. For the ground water systems it ranged between 0.10-0.49 mg/L PO4–P. The mean phosphate levels in all the analyzed surface and groundwater samples were below the recommended maximum contaminant level (MCL by SWSC (Swaziland Water Service Corporation – i.e. 1.0 mg/L for drinking water; 2.0 mg/L for rivers and industrial effluents, and the South African criterion of 1.0 mg/L PO4–P, for sewage effluents being discharged into receiving waters. However, pooled mean values for all the sites were higher than the USEPA criterion of 0.03 mg/L maximum for uncontaminated lakes. Dominant factors considered to have influenced the levels of phosphates in both the surface and groundwater samples analyzed include industrial activities (where present, agricultural activities (including livestock, population density, location (urban, suburban or rural, soil/rock type in the vicinity of the sampling point, climate and rainfall pattern of the area or region concerned.

  11. General Authorisations as a Tool to Promote Water Allocation Reform in South Africa

    Directory of Open Access Journals (Sweden)

    A. Anderson, G. Quibell, J. Cullis and N. Ncapayi

    2007-09-01

    Full Text Available South Africa faces significant inequities in access to and use of water for productive purposes. The National Water Act seeks to address these inequities and introduced a public rights system where water is owned by the people of South Africa and held in custody by the state. This public trust doctrine forms the basis for the State to give effect to its constitutional obligation for redress. Compulsory licensing is a mechanism to proactively reallocate water on a catchment basis to achieve redress, while at the same time promoting economic efficiency and ecological sustainability. During compulsory licensing, all users are required to reapply for their water use entitlement, and a process is followed to allow for a fairer allocation of water between competing users and sectors. Some concerns have been raised that equity may not be achieved through compulsory licensing as historically disadvantaged individuals may not have the capacity to partake in the process. Similarly, the administrative burden of processing large numbers of licences from small scale users may cripple licensing authorities. Moreover, the compulsory licensing process, while encouraging Historically Disadvantaged Individuals (HDIs to apply, may have little impact on poverty if the poorest are not able to participate in the process. General authorisations are proposed as a way of addressing these concerns by setting water aside for specific categories of users. This paper introduces the concept of general authorisations in support of compulsory licensing and outlines some of the implementation challenges.

  12. Surface Tension of Ab Initio Liquid Water at the Water-Air Interface

    CERN Document Server

    Nagata, Yuki; Bonn, Mischa; Kühne, Thomas D

    2016-01-01

    We report calculations of the surface tension of the water-air interface using ab initio molecular dynamics (AIMD) simulations. We investigate the simulation cell size dependence of the surface tension of water from force field molecular dynamics (MD) simulations, which show that the calculated surface tension increases with increasing simulation cell size, thereby illustrating that a correction for finite size effects is required for the small system used in the AIMD simulation. The AIMD simulations reveal that the double-{\\xi} basis set overestimates the experimentally measured surface tension due to the Pulay stress, while the triple and quadruple-{\\xi} basis sets give similar results. We further demonstrate that the van der Waals corrections critically affect the surface tension. AIMD simulations without the van der Waals correction substantially underestimate the surface tension, while van der Waals correction with the Grimme's D2 technique results in the value for the surface tension that is too high. T...

  13. Groundwater - surface water interactions in the Ayeyarwady river delta, Myanmar

    Science.gov (United States)

    Miyaoka, K.; Haruyama, S.; Kuzuha, Y.; Kay, T.

    2012-12-01

    Groundwater is widely used as a water resource in the Ayeyarwady River delta. But, Groundwater has some chemical problem in part of the area. To use safety groundwater for health, it is important to make clear the actual conditions of physical and chemical characteristics of groundwater in this delta. Besides, Ayeyarwady River delta has remarkable wet and dry season. Surface water - groundwater interaction is also different in each season, and it is concerned that physical and chemical characteristics of groundwater is affected by the flood and high waves through cyclone or monsoon. So, it is necessary to research a good aquifer distribution for sustainable groundwater resource supply. The purposes of this study are evaluate to seasonal change of groundwater - surface water interactions, and to investigate the more safety aquifer to reduce the healthy risk. Water samples are collected at 49 measurement points of river and groundwater, and are analyzed dissolved major ions and oxygen and hydro-stable isotope compositions. There are some groundwater flow systems and these water qualities are different in each depth. These showed that physical and chemical characteristics of groundwater are closely related to climatological, geomorphogical, geological and land use conditions. At the upper Alluvium, groundwater quality changes to lower concentration in wet season, so Ayeyarwady River water is main recharge water at this layer in the wet season. Besides, in the dry season, water quality is high concentration by artificial activities. Shallower groundwater is affected by land surface conditions such as the river water and land use in this layer. At lower Alluvium, Arakan and Pegu mountains are main recharge area of good water quality aquifers. Oxygen18 value showed a little affected by river water infiltration in the wet season, but keep stable good water quality through the both seasons. In the wet season, the same groundwater exists and water quality changes through

  14. Distribution of tritium in precipitation and surface water in California

    Science.gov (United States)

    Harms, Patrick A.; Visser, Ate; Moran, Jean E.; Esser, Brad K.

    2016-03-01

    The tritium concentration in the surface hydrosphere throughout California was characterized to examine the reasons for spatial variability and to enhance the applicability of tritium in hydrological investigations. Eighteen precipitation samples were analyzed and 148 samples were collected from surface waters across California in the Summer and Fall of 2013, with repeat samples from some locations collected in Winter and Spring of 2014 to examine seasonal variation. The concentration of tritium in present day precipitation varied from 4.0 pCi/L near the California coast to 17.8 pCi/L in the Sierra Nevada Mountains. Concentrations in precipitation increase in spring due to the 'Spring Leak' phenomenon. The average coastal concentration (6.3 ± 1.2 pCi/L) in precipitation matches estimated pre-nuclear levels. Surface water samples show a trend of increasing tritium with inland distance. Superimposed on that trend, elevated tritium concentrations are found in the San Francisco Bay area compared to other coastal areas, resulting from municipal water imported from inland mountain sources and local anthropogenic sources. Tritium concentrations in most surface waters decreased between Summer/Fall 2013 and Winter/Spring 2014 likely due to an increased groundwater signal as a result of drought conditions in 2014. A relationship between tritium and electrical conductivity in surface water was found to be indicative of water provenance and anthropogenic influences such as agricultural runoff. Despite low initial concentrations in precipitation, tritium continues to be a valuable tracer in a post nuclear bomb pulse world.

  15. Water and Carbon Dioxide Adsorption at Olivine Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kerisit, Sebastien N.; Bylaska, Eric J.; Felmy, Andrew R.

    2013-11-14

    Plane-wave density functional theory (DFT) calculations were performed to simulate water and carbon dioxide adsorption at the (010) surface of five olivine minerals, namely, forsterite (Mg2SiO4), calcio-olivine (Ca2SiO4), tephroite (Mn2SiO4), fayalite (Fe2SiO4), and Co-olivine (Co2SiO4). Adsorption energies per water molecule obtained from energy minimizations varied from -78 kJ mol-1 for fayalite to -128 kJ mol-1 for calcio-olivine at sub-monolayer coverage and became less exothermic as coverage increased. In contrast, carbon dioxide adsorption energies at sub-monolayer coverage ranged from -20 kJ mol-1 for fayalite to -59 kJ mol-1 for calcio-olivine. Therefore, the DFT calculations show a strong driving force for carbon dioxide displacement by water at the surface of all olivine minerals in a competitive adsorption scenario. Additionally, adsorption energies for both water and carbon dioxide were found to be more exothermic for the alkaline-earth (AE) olivines than for the transition-metal (TM) olivines and to not correlate with the solvation enthalpies of the corresponding divalent cations. However, a correlation was obtained with the charge of the surface divalent cation indicating that the more ionic character of the AE cations in the olivine structure relative to the TM cations leads to greater interactions with adsorbed water and carbon dioxide molecules at the surface and thus more exothermic adsorption energies for the AE olivines. For calcio-olivine, which exhibits the highest divalent cation charge of the five olivines, ab initio molecular dynamics simulations showed that this effect leads both water and carbon dioxide to react with the surface and form hydroxyl groups and a carbonate-like species, respectively.

  16. Surface Water Data at Los Alamos National Laboratory 1998 Water Year

    Energy Technology Data Exchange (ETDEWEB)

    D. A. Shaull; M. R. Alexander; R. P. Reynolds; C. T. McLean; R. P. Romero

    1999-02-01

    The principal investigators collected and computed surface water discharge data from 19 stream-gaging stations that cover most of Los Alamos National Laboratory. Also included are discharge data from three springs that flow into Caiion de Vane.

  17. Scaling up ecohydrological processes: role of surface water flow in water-limited landscapes

    CSIR Research Space (South Africa)

    Popp, A

    2009-11-01

    Full Text Available microscale processes like ecohydrological feedback mechanisms and spatial exchange like surface water flow, the authors derive transition probabilities from a fine-scale simulation model. They applied two versions of the landscape model, one that includes...

  18. Evaluation of geologic structure guiding ground water flow south and west of Frenchman Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    McKee, E.H.

    1998-02-01

    Ground water flow through the region south and west of Frenchman Flat, in the Ash Meadows subbasin of the Death Valley ground water flow system, is controlled mostly by the distribution of permeable and impermeable rocks. Geologic structures such as faults are instrumental in arranging the distribution of the aquifer and aquitard rock units. Most permeability is in fractures caused by faulting in carbonate rocks. Large faults are more likely to reach the potentiometric surface about 325 meters below the ground surface and are more likely to effect the flow path than small faults. Thus field work concentrated on identifying large faults, especially where they cut carbonate rocks. Small faults, however, may develop as much permeability as large faults. Faults that are penetrative and are part of an anastomosing fault zone are particularly important. The overall pattern of faults and joints at the ground surface in the Spotted and Specter Ranges is an indication of the fracture system at the depth of the water table. Most of the faults in these ranges are west-southwest-striking, high-angle faults, 100 to 3500 meters long, with 10 to 300 /meters of displacement. Many of them, such as those in the Spotted Range and Rock Valley are left-lateral strike-slip faults that are conjugate to the NW-striking right-lateral faults of the Las Vegas Valley shear zone. These faults control the ground water flow path, which runs west-southwest beneath the Spotted Range, Mercury Valley and the Specter Range. The Specter Range thrust is a significant geologic structure with respect to ground water flow. This regional thrust fault emplaces siliceous clastic strata into the north central and western parts of the Specter Range.

  19. Theoretical Study of Sodium-Water Surface Reaction Mechanism

    Science.gov (United States)

    Kikuchi, Shin; Kurihara, Akikazu; Ohshima, Hiroyuki; Hashimoto, Kenro

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using the ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule on the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. It was found that the estimated rate constant of the former was much larger than the latter. The results are the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by Japan Atomic Energy Agency (JAEA) toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR).

  20. Comparison of Surface Flow Features from Lidar-Derived Digital Elevation Models with Historical Elevation and Hydrography Data for Minnehaha County, South Dakota

    Science.gov (United States)

    Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.

    2009-01-01

    The U.S. Geological Survey (USGS) has taken the lead in the creation of a valuable remote sensing product by incorporating digital elevation models (DEMs) derived from Light Detection and Ranging (lidar) into the National Elevation Dataset (NED), the elevation layer of 'The National Map'. High-resolution lidar-derived DEMs provide the accuracy needed to systematically quantify and fully integrate surface flow including flow direction, flow accumulation, sinks, slope, and a dense drainage network. In 2008, 1-meter resolution lidar data were acquired in Minnehaha County, South Dakota. The acquisition was a collaborative effort between Minnehaha County, the city of Sioux Falls, and the USGS Earth Resources Observation and Science (EROS) Center. With the newly acquired lidar data, USGS scientists generated high-resolution DEMs and surface flow features. This report compares lidar-derived surface flow features in Minnehaha County to 30- and 10-meter elevation data previously incorporated in the NED and ancillary hydrography datasets. Surface flow features generated from lidar-derived DEMs are consistently integrated with elevation and are important in understanding surface-water movement to better detect surface-water runoff, flood inundation, and erosion. Many topographic and hydrologic applications will benefit from the increased availability of accurate, high-quality, and high-resolution surface-water data. The remotely sensed data provide topographic information and data integration capabilities needed for meeting current and future human and environmental needs.

  1. Monitoring and assessment of surface water acidification following rewetting of oxidised acid sulfate soils.

    Science.gov (United States)

    Mosley, Luke M; Zammit, Benjamin; Jolley, Ann-Marie; Barnett, Liz; Fitzpatrick, Rob

    2014-01-01

    Large-scale exposure of acid sulfate soils during a hydrological drought in the Lower Lakes of South Australia resulted in acidification of surface water in several locations. Our aim was to describe the techniques used to monitor, assess and manage these acidification events using a field and laboratory dataset (n = 1,208) of acidic to circum-neutral pH water samples. The median pH of the acidified (pH  H(+) ≈ Mn(II) > Fe(II/III)) but was about 20 % higher on average. Geochemical speciation calculations and XRD measurements indicated that solid phase minerals (schwertmannite and jarosite for Fe and jurbanite for Al) were likely controlling dissolved metal concentrations and influencing measured acidity between pH 2 and 5.

  2. Four Climate Cycles of Recurring Deep and Surface Water Destabilizations on the Iberian Margin

    Science.gov (United States)

    Martrat, Belen; Grimalt, Joan O.; Shackleton, Nicholas J.; de Abreu, Lucia; Hutterli, Manuel A.; Stocker, Thomas F.

    2007-07-01

    Centennial climate variability over the last ice age exhibits clear bipolar behavior. High-resolution analyses of marine sediment cores from the Iberian margin trace a number of associated changes simultaneously. Proxies of sea surface temperature and water mass distribution, as well as relative biomarker content, demonstrate that this typical north-south coupling was pervasive for the cold phases of climate during the past 420,000 years. Cold episodes after relatively warm and largely ice-free periods occurred when the predominance of deep water formation changed from northern to southern sources. These results reinforce the connection between rapid climate changes at Mediterranean latitudes and century-to-millennial variability in northern and southern polar regions.

  3. IMPROVING CYANOBACTERIA AND CYANOTOXIN MONITORING IN SURFACE WATERS FOR DRINKING WATER SUPPLY

    Directory of Open Access Journals (Sweden)

    Jing Li

    2017-06-01

    Full Text Available Cyanobacteria in fresh water can cause serious threats to drinking water supplies. Managing cyanobacterial blooms particularly at small drinking water treatment plants is challenging. Because large amount of cyanobacteria may cause clogging in the treatment process and various cyanotoxins are hard to remove, while they may cause severe health problems. There is lack of instructions of what cyanobacteria/toxin amount should trigger what kind of actions for drinking water management except for Microcystins. This demands a Cyanobacteria Management Tool (CMT to help regulators/operators to improve cyanobacteria/cyanotoxin monitoring in surface waters for drinking water supply. This project proposes a CMT tool, including selecting proper indicators for quick cyanobacteria monitoring and verifying quick analysis methods for cyanobacteria and cyanotoxin. This tool is suggested for raw water management regarding cyanobacteria monitoring in lakes, especially in boreal forest climate. In addition, it applies to regions that apply international WHO standards for water management. In Swedish context, drinking water producers which use raw water from lakes that experience cyanobacterial blooms, need to create a monitoring routine for cyanobacteria/cyanotoxin and to monitor beyond such as Anatoxins, Cylindrospermopsins and Saxitoxins. Using the proposed CMT tool will increase water safety at surface water treatment plants substantially by introducing three alerting points for actions. CMT design for each local condition should integrate adaptive monitoring program.

  4. Thin Water and Ice Films at Mineral Surfaces

    Science.gov (United States)

    Yeşilbaş, Merve; Boily, Jean-François

    2016-04-01

    Mineral-water and ice interactions play important roles in atmospheric cloud formation. They also affect soil biogeochemistry as well as outer-space processes. In this study, thin water and ice films formed on minerals of varied bulk and surface structure, shape, size and surface roughness were probed by Fourier Transform Infrared Spectroscopy (FTIR) and by Dynamic Vapor Adsorption (DVA). Measurements on several types of iron (oxyhydr)oxides, phyllosilicates, orthosilicates, tectosilicates as well as Arizona Test Dust (ATD) and Icelandic volcanic ash constrained our understanding of the molecular-level nature of mineral surface-water and ice interactions. DVA experiments showed that particle size is the key feature controlling water loadings at 25 ° C. Under this condition, nano-sized particles stabilized the equivalence of no more than ˜6 monolayers of water at the near saturation of water vapor while sub-micron sized particles stabilized several thousand layers. This result can be explained by the greater ability of larger sized particles at driving water condensation reactions. Cryogenic FTIR measurements at -10 and -50 ° C revealed that most minerals acquired the thin ice films with similar hydrogen bonding environments as those formed at room temperature.[1,2] These thin ice films have weaker hydrogen bond environments than hexagonal ice (νOH ≈ 3130 cm-1), a result seen by FTIR through predominant O-H stretching modes at νOH ≈ 3408-3425 cm-1. The water bending region (˜1630 cm-1) also reveals that most thin ice films are rather supercooled forms of water. Only the materials with greatest levels of heterogeneity, namely ATD and volcanic ash, stabilized solid forms of water reminiscent to hexagonal ice. This work thus constrains further our understanding of how interfacial ice is stabilized at mineral surfaces, and opens possibilities for future studies focused on atmospheric gas uptake on mineral- water and ice admixtures. [1] Song, X. and Boily, J

  5. Uranium in US surface, ground, and domestic waters. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Reynolds, S.; Owen, P.T.; Ross, R.H.; Ensminger, J.T.

    1981-04-01

    The report Uranium in US Surface, Ground, and Domestic Waters comprises four volumes. Volumes 2, 3, and 4 contain data characterizing the location, sampling date, type, use, and uranium conentrations of 89,994 individual samples presented in tabular form. The tabular data in volumes 2, 3, and 4 are summarized in volume 1 in narrative form and with maps and histograms.

  6. Surface water and groundwater interaction on a hill island

    DEFF Research Database (Denmark)

    Frederiksen, Rasmus Rumph; Rasmussen, Keld Rømer; Christensen, Steen

    – the hill islands – is relatively unknown. This study aims at providing new information about the rainfall-runoff processes in hill island landscapes where surface water and groundwater interaction is expected to have a dominant role and hill-slope processes not. Through stream flow measurements, field...

  7. The interaction of water and hydrogen with nickel surfaces

    NARCIS (Netherlands)

    Shan, Junjun

    2009-01-01

    As nickel and platinum are in the same group of the periodic table, the Ni(111) and Pt(111) surfaces may be expected to show similar interaction with water and hydrogen. However in this thesis, we show these interactions for Ni(111) are quite different from those of Pt(111). Moreover, our results

  8. Observation of water condensate on hydrophobic micro textured surfaces

    Science.gov (United States)

    Kim, Ki Wook; Do, Sang Cheol; Ko, Jong Soo; Jeong, Ji Hwan

    2013-07-01

    We visually observed that a dropwise condensation occurred initially and later changed into a filmwise condensation on hydrophobic textured surface at atmosphere pressure condition. It was observed that the condensate nucleated on the pillar side walls of the micro structure and the bottom wall adhered to the walls and would not be lifted to form a spherical water droplet using environmental scanning electron microscope.

  9. Zearalenone occurrence in surface waters in central Illinois, USA

    Science.gov (United States)

    Zearalenone (ZEN) is an estrogenic secondary metabolite produced by certain fungi that commonly infest important cereal crops, such as corn and wheat. The ability of ZEN to move from contaminated crops to surface waters has been demonstrated previously. This article reports the development of a meth...

  10. Surface water risk assessment of pesticides in Ethiopia

    NARCIS (Netherlands)

    Teklu, B.M.; Adriaanse, P.I.; Horst, ter M.M.S.; Deneer, J.W.; Brink, van den P.J.

    2015-01-01

    Scenarios for future use in the pesticide registration procedure in Ethiopia were designed for 3 separate Ethiopian locations, which are aimed to be protective for the whole of Ethiopia. The scenarios estimate concentrations in surface water resulting from agricultural use of pesticides for a small

  11. Riparian shrub buffers reduce surface water pollutant loads

    Science.gov (United States)

    W. A. Geyer; C. Barden; K. Mankin; D. Devlin

    2003-01-01

    Surface water resources in Kansas often contain concentrations of pesticides, nutrients, and sediments that are of concern to local citizens. The United States Geological Survey reported in 1999 that 97 percent of streams and 82 percent of lakes in Kansas would not fully support all uses as designated by state statutes (U.S. Geological Survey 1999). Bacteria and...

  12. Modelling the effects of surface water flood pulses on groundwater

    NARCIS (Netherlands)

    Schot, P.P.; Wassen, M.J.

    2010-01-01

    Flood pulses in wetlands steer ecosystem development directly through surface water processes and indirectly through the effects of the flood pulse on groundwater. Direct effects on ecosystems are exerted by e.g. inundation and deposition of sediments containing nutrients. Indirect effects include t

  13. The interaction of water and hydrogen with nickel surfaces

    NARCIS (Netherlands)

    Shan, Junjun

    2009-01-01

    As nickel and platinum are in the same group of the periodic table, the Ni(111) and Pt(111) surfaces may be expected to show similar interaction with water and hydrogen. However in this thesis, we show these interactions for Ni(111) are quite different from those of Pt(111). Moreover, our results sh

  14. Surface water risk assessment of pesticides in Ethiopia

    NARCIS (Netherlands)

    Teklu, B.M.; Adriaanse, P.I.; Horst, ter M.M.S.; Deneer, J.W.; Brink, van den P.J.

    2015-01-01

    Scenarios for future use in the pesticide registration procedure in Ethiopia were designed for 3 separate Ethiopian locations, which are aimed to be protective for the whole of Ethiopia. The scenarios estimate concentrations in surface water resulting from agricultural use of pesticides for a small

  15. An Experimental Study of Planing Surfaces Operating in Shallow Water

    Science.gov (United States)

    1976-09-01

    D C APPROVED FOR PUBLIC RELEASE; (7 DISTRIBUTION UNLIMITED 22 1918 PT CLAIME Ar-Th -L’A THI S DOUETI 7E QUALITLY . AVAIILABIJaTECP FURNSR DTO DTIC...Aerodynamic tares were determined by towing the model just above the water surface at various trims and speeds. Only the drag was greatly affected by air

  16. CONTROLLING STORM WATER RUNOFF WITH TRADABLE CREDITS FOR IMPERVIOUS SURFACES

    Science.gov (United States)

    Storm water flow off impervious surface in a watershed can lead to stream degradation, habitat alteration, low base flows and toxic leading. We show that a properly designed tradable runoff credit (TRC) system creates economic incentives for landowners to employ best management p...

  17. Quality of surface-water supplies in the Triangle area of North Carolina, water year 2008

    Science.gov (United States)

    Giorgino, M.J.; Rasmussen, R.B.; Pfeifle, C.A.

    2012-01-01

    Surface-water supplies are important sources of drinking water for residents in the Triangle area of North Carolina, which is located within the upper Cape Fear and Neuse River Basins. Since 1988, the U.S. Geological Survey and a consortium of governments have tracked water-quality conditions and trends in several of the area's water-supply lakes and streams. This report summarizes data collected through this cooperative effort, known as the Triangle Area Water Supply Monitoring Project, during October 2007 through September 2008. Major findings for this period include:

  18. RESIDUAL EFFECT OF LAMBDACYHALOTHRIN (ICON 10% WP ON DIFFERENT SURFACES IN SOUTH OF IRAN

    Directory of Open Access Journals (Sweden)

    H. Ladonni

    1994-08-01

    Full Text Available An investigation was made to study the residual activity and air-borne effect of lambdacyhalothrin (Icon 10 WP at 30, 40 and 50 a.i. mg/rn2 against An.stephensi in hut scale trials on different surfaces in Mamasani, and Rudan, south of Iran. Bio-assay contact mortality test with Icon at 30 a.i. mgl/m2 on plaster, cement and wood surfaces decreased from 100% to 51.4%, 53% and 63.8% after 84, 80 and 107 days of hut spraying, respectively. At 40 a.i mg/m2 Icon showed longer residual activity than the 30 mg/rn2, i.e. the mortality rate deceased from 100% to 50.7% for plaster, to 52.5% for cement and to 53.5% for wood surfaces, after 105, 105 and 124 days of hut spraying, respectively. Icon at 50 a.i. mg/m2 showed longer residual activity than the former dosages, i.e. the mortality dropped from 100% to 62.1% for plaster, to 50.7% for cement and to 90.4% for wooden surfaces, after 124 days of hut spraying, respectively. The result of air home tests showed that Icon has negligible or slight killing effect on An.stephensi, i.e. at 30. 40 and 50 a.i. mg/m2, the mortality rates dropped from 100% to about 60% after 10, 15 and 25 days of hut spraying, respectively. Based on the results of this study lambdacyhalothrin at 50/m2 had a residual activity for more than 4 months on different surface. It could be concluded that, lambdacyhalothrin at 50 mg/m2 might be a candidate dosage for continuation of study in village scale vial in south of Iran.

  19. Index of surface-water stations in Texas, January 1988

    Science.gov (United States)

    Rawson, Jack; Carrillo, E.R.; Buckner, H.D.

    1988-01-01

    As of January 1, 1988, the surface-water data-collection network in Texas included 368 continuous streamflow, 12 continuous or daily reservoir-content, 38 gage height, 15 crest-stage partia 1-record, 4 periodic discharge through range, 32 floodhydrocjraph partial-record, 9 flood-profile partial-record, 36 low-flow partial-record 45 daily chemical-quality, 19 continuous-recording water-quality, 83 periodic biological, 19 lake surveys, 160 periodic organic and (or) nutrient, 3 periodic insecticide, 33 periodic pesticide, 20 automatic sampler, 137 periodic minor elements, 125 periodic chemical-quality, 74 periodic physica1-organic, 24 continuous-recording three- or four-parameter water-quality, 34 periodic sediment, 21 continuous-recording temperature, and 30 national stream-quality accounting network stations. Plate 1 shows the location of surface-water streamflow or reservoir-content and chemicalquality or sediment stations in Texas. Plate 2 shows the location of partial-record surface-water stations.

  20. Concentration level and geographical distribution of nitrobenzene in Chinese surface waters

    Institute of Scientific and Technical Information of China (English)

    GAO Jijun; LIU Linghua; LIU Xiaoru; ZHOU Huaidong; WANG Zijian; HUANG Shengbiao

    2008-01-01

    Nitrobenzene was reported to occur at relatively high concentrations in some Chinese surface water and to cause an environmental pollution event in 2005. In order to map the distribution of nitrobenzene in the Chinese surface water throughout China, surface water samples were collected from over 600 sites in the 7 major watersheds and three drainage areas. The samples were analyzed for concentration of nitrobenzene. Overall, nitrobenzene was more frequently detected at higher concentrations in the rivers of North China, including Songhuajiang River, Liaohe River, Haihe River, Yellow River, Huaihe River and Northwest drainage area rivers, compared with those in the rivers of South China, including Yangtze river, Pearl river, Southeast drainage area rivers and Southwest drainage rivers. The detection rate of nitrobenzene was the 83.2 % for all the samples, with a mean value of 18.1 ng/L and a range of < 0.3-8,450.0 ng/L. The highest mean concentration of nitrobenzene was observed in the Yellow River, followed by Huaihe River . The results of this investigation indicated that nitrobenzene should be of particular concern in China and its ecological and health risk should be assessed.