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1.
High flows and deep waters associated with thermal dischargecanals invoke safety concerns and preclude the use of conventional fish sampling methodologies. Despite these challenges, it is critical that assessments of thermal effectsfrom power generation do not rely solely on data collected in the plume, but also focus on fish living in the canal, particularly in regions above the zone of tempering influence. We deployed a fixed underwater videography apparatus to monitor the community composition and abundance patterns of fish in the Nanticoke thermal generating discharge canal on the north shore of Lake Erie from February 1, 1999 until July 31, 1999. We also compared the number of species observed using video to angling surveys, visual observations through the air/water interface and two modified netting procedures. Our results indicate that videography permitted the detectionof the most species and the highest number of individuals. Variable visibility was the largest limitation of this approach. The addition of infrared lighting for low light conditions and a series of cameras positioned at several depths would be a cost effective, safe, and efficient method ofassessing community structure and behaviour of fish in thermal discharge canals. 相似文献
2.
To meet the growing energy demand worldwide, oil and gas exploration and production activities have increased rapidly both in onshore and offshore areas. The produced oil from the ocean bed is transported onshore either by ship or pipeline. This has increased the risk of oil spill in the coastal area. In order to prepare an emergency preparedness plan and to assess the magnitude of risk involved in transporting and offloading oil, oil spill simulation studies play an important role. This paper describes a simulation of oil spill in coastal bay of Arabian Gulf where new developments are taking place using MIKE 21 model. The developments include a diesel based thermal power plant near Sir Baniyas Island, which is an ecological fragile area. Based on the project activity, two probable scenarios, one for diesel leak (250 m3/h) for 1 h and the other for instantaneous spill (500 m3) are considered. The MIKE 21 model was calibrated for hydrodynamics using measured field data followed by diesel-spill simulation to track its movement in the Arabian Gulf. The results for both leak and instantaneous spill indicate that spilled diesel will not move towards the Sir Banyas Island and more than 45% of the diesel will be evaporated within 48 h of oil spill. Based on the results, a clean up and contingency plan is proposed to mitigate the adverse impacts arising due to diesel spill in the study area. 相似文献
3.
Statistical analysis of heavy metal concentrations in sediment was studied to understand the interrelationship between different parameters and also to identify probable source component in order to explain the pollution status of selected estuaries. Concentrations of heavy metals (Cu, Zn, Cd, Fe, Pb, Cr, Hg and Mn) were analyzed in sediments from Juru and Jejawi Estuaries in Malaysia with ten sampling points of each estuary. The results of multivariate statistical techniques showed that the two regions have different characteristics in terms of heavy metals selected and indicates that each region receives pollution from different sources. The results also showed that Fe, Mn, Cd, Hg, and Cu are responsible for large spatial variations explaining 51.15% of the total variance, whilst Zn and Pb explain only 18.93 of the total variance. This study illustrates the usefulness of multivariate statistical techniques for evaluation and interpretation of large complex data sets to get better information about the heavy metal concentrations and design of monitoring network. 相似文献
4.
5.
Environmental Modeling & Assessment - Lucas–Washburn equation is a fundamental expression which is used to describe capillary rise in porous materials according to average pore radius,... 相似文献
6.
Doygun H 《Environmental monitoring and assessment》2009,158(1-4):471-478
The main objective of this study is to quantify areal loss of olive groves due to urban sprawl of the city of Kahramanmara?, Turkey. Spatial changes were analysed by interpreting the digitized data derived from a black–white monoscopic aerial photograph taken in 1985, panchromatic IKONOS image of 2000 and two pan-sharpened Quickbird images of 2004 and 2006. Data obtained revealed that the area of olive groves decreased by 25% from 460.55 ha in 1985 to 344.46 in 2006, while the number of parcels increased from 170 to 445. Of the total areal loss, 60% was due to building constructions, with the rest being due to clear-cut for new residential gardens composed of exotic plants, new buildings, or new roads. Rapid population growth, increased land prices due to urban expansion, and abandonment of agricultural practices to construction of multi-storey buildings were the main causes of the process that transformed the olive groves into urbanized areas. Results pointed to an urgent need to (1) revise the national and municipal land management practices, (2) balance the gap between the short- and long-term economic benefits that urban and community development plans ignore, and (3) monitor land-use changes periodically by using high resolution satellite images. 相似文献
7.
Spatial distribution of pH, electrical conductivity (EC), total dissolved solids (TDS), fluoride and total iron content of
ground water samples collected from the muvattupuzha river basin, Kerala, India, has been studied for pre monsoon and post
monsoon periods of year 2001. Results showed the groundwater of the basin is acidic for which the pH values ranged between
5.5 and 8.0. Average EC was found to be less than 100 μS/cm, for most of the study region. The pre monsoon minimum and maximum
TDS were found as 25.6 and 227.84 mg/L respectively, where as post monsoon values ranged between 16 and 162.56 mg/L. The relatively
low EC and TDS values found both during the seasons in the lateritic terrain of the river basin signifies the lower residence
time of ground water with the country rock. This makes the groundwater quality of this river basin as good. Pre monsoon season
samples showed high total iron content than that during the post monsoon period. During the study period values of the fluoride
contents were found to be within the permissible limits. 相似文献
8.
Data management is becoming increasingly simple and complex at the same time. The challenge is to effectively use the increasing number of tools available to manage increasing amounts of environmental information for purposes of data capture, analysis, display, sharing and storage. Government is no longer the main collector and provider of data. Community groups possess vast amounts of data collected through daily work of monitoring the environment in their local community. The chief concerns are data access, sharing, integrity and comparability. The capacity of groups to sustain data management is the key to making the sharing possible. The Southeast Environmental Association has been working with Environment Canada to develop a community, on-line database that will be linked to other geo-spatial data sets to allow instant access to geo-referenced data. 相似文献
9.
Nitrogen leaching is a world-wide concern for the quality of ground- and surfacewater. Measures to abate this is still limited by a lack of understanding mechanisms behind all factors describing the leaching process, time lags between countermeasures and improvement in waterquality and spatial distribution of nitrogen leaching. The purpose of this study was to do an initial test of the SOILNDB model system which is built on the existing mechanistic SOIL and SOILN models and an automatic parameterization procedure for use of simplified input data. The test was done by simulating nitrogen leaching from each of the 150 fields in a small catchment during a three-year study period. The simulated mean root-zone nitrogen leaching rate from all the fields in the catchment was compared to measurements of nitrogen flow in the stream draining the catchment and showed good agreement in between-year dynamics. 相似文献
10.
Poté J Goldscheider N Haller L Zopfi J Khajehnouri F Wildi W 《Environmental monitoring and assessment》2009,154(1-4):337-348
The origin and distribution of microbial contamination in Lake Geneva's most polluted bay were assessed using faecal indicator bacteria (FIB). The lake is used as drinking water, for recreation and fishing. During 1 year, water samples were taken at 23 points in the bay and three contamination sources: a wastewater treatment plant (WWTP), a river and a storm water outlet. Analyses included Escherichia coli, enterococci (ENT), total coliforms (TC), and heterotrophic plate counts (HPC). E. coli input flux rates from the WWTP can reach 2.5 x 10(10) CFU/s; those from the river are one to three orders of magnitude lower. Different pathogenic Salmonella serotypes were identified in water from these sources. FIB levels in the bay are highly variable. Results demonstrate that (1) the WWTP outlet at 30 m depth impacts near-surface water quality during holomixis in winter; (2) when the lake is stratified, the effluent water is generally trapped below the thermocline; (3) during major floods, upwelling across the thermocline may occur; (4) the river permanently contributes to contamination, mainly near the river mouth and during floods, when the storm water outlet contributes additionally; (5) the lowest FIB levels in the near-surface water occur during low-flow periods in the bathing season. 相似文献
11.
Atmospheric concentrations of nitric acid (HNO3), sulfur dioxide (SO2), particulate nitrate and particulate sulfate on the urban- and mountain-facing sides of Mt. Gokurakuji were measured from November 2002 to October 2003, in order to evaluate
the effects of anthropogenic activity on air quality and dry deposited nitrate and sulfate on the surfaces of pine foliage.
The results showed that HNO3, SO2 and concentrations were significantly higher (P < 0.05) on the urban-facing side (1.54, 2.48 and 0.65 μg m−3, respectively) than the mountain-facing side (0.67, 1.19 and 0.37 μg m−3, respectively), while concentrations did not differ significantly between the two sides (urban-facing: 2.80 μg m−3; mountain−facing: 2.05 μg m−3). Indirect estimates of dry deposition rates of nitrate and sulfate to the surfaces of pine foliage based on the measured
concentrations approximately agreed with the measured values determined by the foliar rinsing technique in a previous study.
It was found that HNO3 was the major source (approximately 80%) of dry deposited nitrate on pine foliage, while the contribution from was about equal to that from SO2. In conclusion, HNO3 and SO2 appear to be dominant species reflecting higher dry deposition rates of nitrate and sulfate on the urban-facing side compared
to the mountain-facing side of Mt. Gokurakuji. 相似文献
12.
Sulfate () concentrations and fluxes were studied for multiple storm events in the Point Peter Brook watershed, a glaciated, forested
watershed located in Western New York, USA. Investigations were performed across one large (696 ha) and three small (1.6–3.4 ha)
catchments with varying extent of riparian and wetland areas. Concentrations of in groundwater sources (mean values: 238–910 μmolc L−1) were considerably greater than concentrations recorded for rainfall (60 μmolc L−1) and throughfall (72–129 μmolc L−1). Seasonality in concentrations was most pronounced for valley-bottom riparian waters with maximum concentrations in late winter–spring (February–March)
and a minimum in late summer (August). Concentrations of in wetland water were considerably less than riparian water indicating the likelihood of reduction in anoxic wetland conditions. Storm events displayed a dilution pattern in concentrations with a minimum coinciding with the maximum in throughfall contributions. End member mixing analysis (EMMA)
was able to predict the storm event concentrations of for four of the six comparisons. Concentrations of at the outlet of the large (696 ha) catchment were much greater than values recorded for the smaller catchments. Exports
of in streamflow exceeded the inputs from atmospheric deposition suggesting that watersheds like Point Peter Brook may not show
any immediate response to decreases in atmospheric deposition. 相似文献
13.
Singh KP Singh VK Malik A Sharma N Murthy RC Kumar R 《Environmental monitoring and assessment》2007,131(1-3):237-254
Rain water samples were collected to study the chemical composition of wet atmospheric precipitation (first event) over the
Lucknow city in the northern Indo-gangetic alluvial plains. The samples were collected in the month of July, 2005 from different
sites. The wet precipitation samples were analyzed for pH, EC, major ions (, Cl−, , , , F−, Na+, K+, Ca2+, Mg2+, ) and heavy metals (As, Cd, Al, Co, Cr, Cu, Fe, Mn, Mo, Ni, Hg, Pb, Se, Sn, Ti, V, Zn). The pH values of wet precipitation
samples ranged between 6.5 and 8.7. The analysis of linear regression applied to the set of studied variables and computation
of neutralization factors showed that neutralization occurred in precipitation samples and Ca2+ had the maximum neutralization capacity. It was found that Cl−, , Ca2+, Mg2+, Na+ and K+ in the precipitation samples originated mainly from crustal/anthropogenic sources in the region. On an average Fe, and Al
accounted for >72% of the total concentration of trace metals in the wet precipitation samples followed by Zn (>10%). Enrichment
factors calculated for heavy metals over reference background level in seawater and Earth’s crust showed relatively higher
enrichment of Zn. The principal component analysis (PCA) identified the possible sources of ionic species and heavy metals
in the wet precipitation samples. 相似文献
14.
Leaching of nitrogen, phosphorus, TOC and COD from the biosolids of the municipal wastewater treatment plant of Thessaloniki 总被引:1,自引:0,他引:1
Biosolids from the WWTP of Thessaloniki were examined for the leaching of phosphorus (as ), nitrogen (as and ), and organic matter (as TOC and COD), using two tests: (1) a pH static leaching test and (2) a characterization test, relating
contaminant release to the liquid to solid (L/S) ratio. Moreover, a Microtox toxicity test was conducted, to examine the pH
dependency of the toxicity of the sludge leachate on the Vibrio fischeri bacterium. Maximum phosphorus release was observed at pH < 3 and at pH > 10. Ammonium nitrogen exhibited maximum leachability
at near neutral pH conditions, while nitrate nitrogen exhibited a mild increase in the leachate, as the leachant pH increased
from 2 to 12. Both TOC and COD exhibited an increase in the leachate concentration, as the leachant pH was increased from
2 to 12. Ecotoxicological analysis showed that maximum toxicity occurred at very low and very high pH-conditions. As liquid-to-solid
ratio increased, the leachate concentration (in mg/l) of all parameters studied decreased. The results of the study were used
to conduct a release assessment estimate for the case of Thessaloniki. 相似文献
15.
Inamdar S 《Environmental monitoring and assessment》2007,133(1-3):347-363
Storm event exports of dissolved were explored for multiple events in the Point Peter Brook watershed (PPBW), a glaciated, forested watershed located in Western
New York, USA. Investigations were performed across four catchments (1.6–696 ha) with varying topography and the extent of
surface-saturated areas. While wetland and riparian waters were important sources of during non-storm periods, throughfall and litter leachate were the dominant contributors of during storm events. Ammonium concentrations in catchment discharge displayed a sinusoidal seasonal pattern with a maximum
during early spring (March) and a minimum in late summer (August–September). Storm event concentrations of in streamflow were much greater than baseflow values and showed a consistent temporal pattern with an increase in concentrations
on the hydrograph rising limb, a peak at or before the discharge peak, followed by a decline in concentrations. Storm event
patterns of DON were similar to while the patterns of differed from for the summer and fall events. The storm event expression of was attributed to throughfall and throughfall-mediated leaching of the litter layer. The reactive behavior of precluded its use in an end member mixing model (EMMA) for predicting streamflow concentrations. While concentrations of
in precipitation and streamflow were high for the spring events, exports of in streamflow were highest for the large and intense storm events. Baseflow concentrations increased with the percent wetland/saturated area in the catchment but the same trend did not hold for storm-event
concentrations. 相似文献
16.
Diapouli E Chaloulakou A Mihalopoulos N Spyrellis N 《Environmental monitoring and assessment》2008,136(1-3):13-20
Simultaneous indoor and outdoor PM10 and PM2.5 concentration measurements were conducted in seven primary schools in the Athens area. Both gravimetric samplers and continuous
monitors were used. Filters were subsequently analyzed for anion species. Moreover ultrafine particles number concentration
was monitored continuously indoors and outdoors. Mean 8-hr PM10 concentration was measured equal to 229 ± 182 μg/m3 indoors and 166 ± 133 μg/m3 outdoors. The respective PM2.5 concentrations were 82 ± 56 μg/m3 indoors and 56 ± 26 μg/m3 outdoors. Ultrafine particles 8-h mean number concentration was measured equal to 24,000 ± 17,900 particles/cm3 indoors and 32,000 ± 14,200 particles/cm3 outdoors. PM10 outdoor concentrations exhibited a greater spatial variability than the corresponding PM2.5 ones. I/O ratios were close or above 1.00 for PM10 and PM2.5 and smaller than 1.00 for ultrafine particles. Very high I/O ratios were observed when intense activities took place. The
initial results of the chemical analysis showed that accounts for the 6.6 ± 3.5% of the PM10 and for the 3.1 ± 1.4%.The corresponding results for PM2.5 are 12.0 ± 7.7% for and 3.1 ± 1.9% for . PM2.5
indoor concentrations were highly correlated with outdoor ones and the regression line had the largest slope and a very low
intercept, indicative of no indoor sources of fine particulate . The results of the statistical analysis of indoor and outdoor concentration data support the use of as a proper surrogate for indoor PM of outdoor origin. 相似文献
17.
Demirak A 《Environmental monitoring and assessment》2007,129(1-3):189-196
In this study, the chemical composition of the rainwater in Yatağan, which is a region surrounding a coal power plant was
investigated from February to April 2002. Rainwater samples were obtained from Yatağan, located northwest of Muğla City in
Turkey. pH values and concentrations of major ions (Ca2+, Na+, K+, , , ) in the rainwater samples were analyzed. The pH varied from 5.1 to 7.9 with an average of 6.7 which was in alkaline range
considering 5.6 as the neutral pH of cloud water in equilibrium with atmospheric CO2. In the total of 30 rain events, only three events were observed with water in the acidic range (<5.6), which occurred after
continuous rains. The equivalent concentration of components followed the order: Ca2+ > > Na+ > > > K+ > H+. The anion and cation concentrations in the rainwater samples showed a high sulphate concentration (131 μEq/l), as well as
high sodium (40 μEq/l) and calcium (298 μEq/l) concentrations. These values indicate that one probable source of the high
sodium concentration is fly ash, after the coal burning process and the power plant can be effective on level concentrations in rainwater. In addition, the dust-rich local and surrounding limestone environment might have caused the
high concentration of Ca2+ in rainwater of the Yatağan Basin. Due to a large contribution of these cations to the sulphate neutralization action, the
rainwater of this region displays only a moderate acidity, which does not cause significant environmental impact. 相似文献
18.
Factors controlling the salinity in groundwater in parts of Guntur district, Andhra Pradesh, India 总被引:1,自引:0,他引:1
Subba Rao N 《Environmental monitoring and assessment》2008,138(1-3):327-341
Groundwater chemistry has been studied to examine the associated hydrogeochemical processes operating for the development
of salinity in the groundwater in parts of Guntur district, Andhra Pradesh, India. The study area is underlain by charnockites
and granitic gneisses associated with schists of the Precambrian Eastern Ghats. Groundwater is the main resource for irrigation
besides drinking. Chemical parameters, pH, EC, TDS, Ca2+, Mg2+, Na+, K+, , , Cl−, , , F− and SiO2, are taken into account. Groundwater is of brackish type. Na+−Cl− facies dominates the groundwater. Examination of compositional relations and mineral saturation states shows that the ion
exchange of Ca2+ for adsorbed Na+, evapotranspiration, dissolution of soil salts, dissolution of NaCl and CaSO4, and precipitation of CaCO3 are the dominant hydrogeochemical processes associated with the groundwater composition in the area. Evapotranspiration causes
accumulation of salts in the soil/weathered zone. These salts reach the water table by leaching through infiltrating recharge
water. A positive relation between depth to water table and TDS with season supports this inference. The effects of human
activities, such as intensive and long-term irrigation, irrigation-return-flow, application of unlimited agricultural fertilizers
and recycling of saline groundwater, act to further increase the salinity in the groundwater. Therefore, the groundwater quality
increases towards the flow path, while the post-monsoon groundwater shows higher concentrations of TDS, Na+, Mg2+, Cl−, , , F− and SiO2 ions. The study could help to understand the hydrogeochemical characteristics of the aquifer system for taking effective
management measures to mitigate the inferior groundwater quality for sustainable development. 相似文献
19.
Visibility impairing aerosols in the urban atmosphere of Delhi 总被引:1,自引:0,他引:1
Singh T Khillare PS Shridhar V Agarwal T 《Environmental monitoring and assessment》2008,141(1-3):67-77
To study the visual air quality of Delhi, size fractionated aerosols – coarse and fine fractions of PM10 – were collected and analysed for and EC at three sites with different background activities. The analysed species constitute a smaller portion of coarse fraction
(39%) but a larger portion of fine fraction (69%). The sampling was performed from June 2003 to November 2003 which covers
monsoon and post monsoon seasons.Aerosol data was used to describe the spatial variation of Visibility Range as a function
of chemical composition of visibility impairing aerosols. During the study period, visibility was found to be poor varying
between 4.7 and 13 km with an average value of 9.4 km. It is observed that visibility impairment was more due to carbonaceous
aerosol followed by sulphate. 相似文献
20.
Manchar Lake is the largest natural freshwater lake in Pakistan. The Lake has received less fresh water in past few years.
In addition, drainage water is being discharged in the Lake through Main Nara Valley Drain (MNVD) since many years. Consequently,
concern has grown regarding the water quality of the Lake. The aim of this study was to assess the water quality of Manchar
Lake and MNVD and the objectives were to determine physiochemical properties and the concentrations of common cations and
anions as well as seven trace metals i.e. Cu, Ni, Zn, Co, Fe, Pb and Cd. The concentration of the trace metals were determined
by simultaneous preconcentration and solvent extraction using flame atomic absorption spectrometer. Results of physicochemical
parameters of Manchar Lake water samples showed mean pH 8.4 (±0.2), conductivity 2,310.3 (±581.3) μS cm−1 and hardness (as CaCO3) 213.1 (±62.3) mg l−1. Mean concentrations of cations and anions were Na 521.5 (±49.7), Cl− 413.6 (±225.7), Ca 70.7 (±12.9), Mg 56.2 (±28.9), K 17.6 (±6.5), 0.34 (±0.2) and 0.02 (±0.01) mg l−1. Mean concentrations of trace metals were Zn 15.7 (±1), Fe 12 (±3.5), Pb 9 (±2.7), Cu 8.9 (±7.7), Ni 4.3 (±3.4), Co 4 (±3.4)
and Cd 1.1 (±1) μg l−1. MNVD water samples showed mean pH 8.9 (±0.8), conductivity 1,735.7 (±567.8) μS cm−1 and hardness (as CaCO3) 184.8 (±32.4) mg l−1. In MNWD, the mean concentrations of cations and anions were Na 482.7 (±11.7), Cl− 395.7 (±271.5), Ca 79.1 (±23.5), Mg 54.2 (±28.1), K 26.2 (±21.3), NO−3 0.5 (±0.3) and 0.1 (±0.1) mg l−1. Mean concentrations of trace metals observed in MNWD water were Fe 14.9(±3.5), Cd 8.3 (±9.4), Pb 6.9 (±2.4), Cu 6.6 (±3.1),
Zn 6.2 (±1.8), Co 4.5 (±2.7), and Ni 3.5 (±2.9) μg l−1. The pH of both Manchar Lake and MNVD waters and concentration of Pb in Manchar Lake and concentration of Cd in MNVD water
were higher than the World Health Organisation’s guideline values for the drinking water quality. The water quality of Manchar
Lake was found degraded. 相似文献