共查询到20条相似文献,搜索用时 10 毫秒
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Jane T. Bhaskar S. C. Tripathy P. Sabu C. M. Laluraj S. Rajan 《Environmental monitoring and assessment》2016,188(4):224
Phytoplankton species distribution and composition were determined by using microscopy and pigment ratios in the Kongsfjorden during early autumn 2012. Variation in sea surface temperature (SST) was minimal and matched well with satellite-derived SST. Nutrients were generally limited. Surface phytoplankton abundance ranged from 0.21?×?103 to 10.28?×?103 cells L?1. Phytoplankton abundance decreased with depth and did not show any significant correlation with chlorophyll a (chl a). Column-integrated phytoplankton cell counts (PCC) ranged from 94.3?×?106 cells m?2 (Kf4) to 13.7?×?106 cells m?2 (Kf5), while chl a was lowest at inner part of the fjord (6.3 mg m?2) and highest towards the mouth (24.83 mg m?2). Biomass from prymnesiophytes and raphidophytes dominated at surface and 10 m, respectively. The contribution of Bacillariophyceae to biomass was low. Generally, heterotrophic dinoflagellates were great in abundance (12.82 %) and ubiquitous in nature and were major contributors to biomass. Various chl pigments (chl b, chl c, phaeopigments (phaeo)) were measured to obtain pigment/chl a ratios to ascertain phytoplankton composition. Phaeo were observed only in inner fjord. Chl b:a ratios and microscopic observations indicated dominance of Chlorophyceae at greater depths than surface. Furthermore, microscopic observations confirmed dominance of chl c containing algae throughout the fjord. The study indicates that pigment ratios can be used as a tool for preliminary identification of major phytoplankton groups. However, under the presence of a large number of heterotrophic dinoflagellates such as Gymnodinium sp. and Gyrodinium sp., pigment signatures need to be supplemented by microscopic observations. 相似文献
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Michael A. Mallin Virginia L. Johnson Scott H. Ensign 《Environmental monitoring and assessment》2009,159(1-4):475-491
Water quality data at 12 sites within an urban, a suburban, and a rural stream were collected contemporaneously during four wet and eight dry periods. The urban stream yielded the highest biochemical oxygen demand (BOD), orthophosphate, total suspended sediment (TSS), and surfactant concentrations, while the most rural stream yielded the highest total organic carbon concentrations. Percent watershed development and percent impervious surface coverage were strongly correlated with BOD (biochemical oxygen demand), orthophosphate, and surfactant concentrations but negatively with total organic carbon. Excessive fecal coliform abundance most frequently occurred in the most urbanized catchments. Fecal coliform bacteria, TSS, turbidity, orthophosphate, total phosphorus, and BOD were significantly higher during rain events compared to nonrain periods. Total rainfall preceding sampling was positively correlated with turbidity, TSS, BOD, total phosphorus, and fecal coliform bacteria concentrations. Turbidity and TSS were positively correlated with phosphorus, fecal coliform bacteria, BOD, and chlorophyll a, which argues for better sedimentation controls under all landscape types. 相似文献
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A probabilistic water quality index for river water quality assessment: a case study 总被引:1,自引:0,他引:1
Nikoo MR Kerachian R Malakpour-Estalaki S Bashi-Azghadi SN Azimi-Ghadikolaee MM 《Environmental monitoring and assessment》2011,181(1-4):465-478
Available water quality indices have some limitations such as incorporating a limited number of water quality variables and providing deterministic outputs. This paper presents a hybrid probabilistic water quality index by utilizing fuzzy inference systems (FIS), Bayesian networks (BNs), and probabilistic neural networks (PNNs). The outputs of two traditional water quality indices, namely the indices proposed by the National Sanitation Foundation and the Canadian Council of Ministers of the Environment, are selected as inputs of the FIS. The FIS is trained based on the opinions of several water quality experts. Then the trained FIS is used in a Monte Carlo analysis to provide the required input-output data for training both the BN and PNN. The trained BN and PNN can be used for probabilistic water quality assessment using water quality monitoring data. The efficiency and applicability of the proposed methodology is evaluated using water quality data obtained from water quality monitoring system of the Jajrood River in Iran. 相似文献
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This paper presents monitoring results of daily brick kiln stack emission and the derived emission factors. Emission of individual air pollutant varied significantly during a firing batch (7 days) and between kilns. Average emission factors per 1,000 bricks were 6.35–12.3 kg of CO, 0.52–5.9 kg of SO2 and 0.64–1.4 kg of particulate matter (PM). PM emission size distribution in the stack plume was determined using a modified cascade impactor. Obtained emission factors and PM size distribution data were used in simulation study using the Industrial Source Complex Short-Term (ISCST3) dispersion model. The model performance was successfully evaluated for the local conditions using the simultaneous ambient monitoring data in 2006 and 2007. SO2 was the most critical pollutant, exceeding the hourly National Ambient Air Quality Standards over 63 km2 out of the 100-km2 modelled domain in the base case. Impacts of different emission scenarios on the ambient air quality (SO2, PM, CO, PM dry deposition flux) were assessed. 相似文献
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Harwell MC Surratt DD Barone DM Aumen NG 《Environmental monitoring and assessment》2008,147(1-3):445-462
Agricultural and urban runoff pumped into the perimeter canals of the Arthur R. Marshall Loxahatchee National Wildlife Refuge (Refuge), a 58,320-ha soft-water wetland, has elevated nutrients which impact the Refuge interior marsh. To best manage the Refuge, linkages between inflows to the perimeter canals and environmental conditions within the marsh need to be understood. Conductivity, which typically is high in the canals and lowest at the most interior sites, was used as a surrogate tracer to characterize patterns of constituent transport. The Refuge was initially classified into four zones based upon patterns and variability in conductivity data: Canal Zone; Perimeter Zone (canal to 2.5 km into the interior); Transition Zone (2.5 to 4.5 km from the canal); Interior Zone (>4.5 km from the canal). Conductivity variability declined from the Perimeter to the Interior Zone, with the highest variability in the marsh observed in the Perimeter Zone and the lowest variability observed in the Interior Zone. Analysis of other water quality parameters indicated that conditions in the Perimeter and Transition Zones were different, and more impacted, than in the Interior Zone. In general, there was a positive relationship between structure inflows and canal phosphorus concentrations, including discharges from treatment wetlands and bypasses of untreated water. This classification approach is applicable for stratified sampling designs, resolving spatial bias in water quality models, and in aiding in management decisions about resource allocation. 相似文献
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Barbara Ann Stewart 《Environmental monitoring and assessment》2011,173(1-4):941-953
Despite the fact that the establishment and maintenance of blue gum plantations can potentially result in the removal of riparian vegetation, the presence of increased levels of sediments, pesticides, and nutrients, and consequently, the loss of in-stream biodiversity, few studies exist that have looked at the impacts of timber plantations on in-stream biota. The goals of this study were thus to determine water quality, riparian condition, and in-stream biodiversity values of local streams draining blue gum plantations in the Marbellup Brook catchment in Western Australia and to compare these values with those of streams associated with other land uses. Selected water quality and habitat variables and in-stream macroinvertebrate biodiversity were measured in 2006 and 2007 at 28 sites falling into five broad categories based on the predominant land use within 200 m of each study reach. Overall, the results indicated that ??blue gum plantation?? sites often had better water quality, riparian condition, and biodiversity values than ??pasture unfenced,?? and sometimes ??pasture fenced?? sites, but water quality and biodiversity values at these sites were not as good as those associated with ??remnant?? native vegetation sites. The location of the blue gum plantation sites along the disturbance gradient investigated was attributed to both present management and past land uses in the subcatchments investigated. As this study was conducted at a time when blue gum plantations were in an on-growing phase, it was recommended that future research on the impact of blue gum plantations on waterways in southwestern Australia should include an investigation of the impacts of timber clear-cutting and extraction. Longer-term cumulative and downstream effects of blue gum plantations on local waterways also need to be investigated. 相似文献
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Groundwater is connected to the landscape above and is thus affected by the overlaying land uses. This study evaluated the impacts of land uses upon groundwater quality using trilinear analysis. Trilinear analysis is a display of experimental data in a triangular graph. Groundwater quality data collected from agricultural, septic tank, forest, and wastewater land uses for a 6-year period were used for the analysis. Results showed that among the three nitrogen species (i.e., nitrate and nitrite (NOx), dissolved organic nitrogen (DON), and total organic nitrogen (TON)), NOx had a high percentage and was a dominant species in the groundwater beneath the septic tank lands, whereas TON was a major species in groundwater beneath the forest lands. Among the three phosphorus species, namely the particulate phosphorus (PP), dissolved ortho phosphorus (PO 4 3?? ) and dissolved organic phosphorus (DOP), there was a high percentage of PP in the groundwater beneath the septic tank, forest, and agricultural lands. In general, Ca was a dominant cation in the groundwater beneath the septic tank lands, whereas Na was a dominant cation in the groundwater beneath the forest lands. For the three major anions (i.e., F?, Cl?, and SO 4 2?? ), F? accounted for <1 % of the total anions in the groundwater beneath the forest, wastewater, and agricultural lands. Impacts of land uses on groundwater Cd and Cr distributions were not profound. This study suggests that trilinear analysis is a useful technique to characterize the relationship between land use and groundwater quality. 相似文献
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WPI指数在地表水环境质量评价中的运用 总被引:3,自引:1,他引:3
在地表水环境质量评价中提出了 WPI指数 ,并对其使用方法作了详细说明 ,提供了计算 API指数和判定水质类别的 wpix( data,bh,lx)函数 相似文献
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A human impact assessment (HIA) model was developed to guide research to understand how changes in a fishery can impact fishermen and fishing communities. Path analysis demonstrates that job satisfaction is an important variable intervening between marine governance and well-being. Individual-level variables in the demographic latent variable influence aspects of job satisfaction as well as well-being. It is variance in management that influences satisfaction with fishing which has a direct effect on well-being. In the HIA model, the three components of job satisfaction (self-actualization, income, and psycho-social) have the greatest total impact on well-being. The model also indicates complex relationships between management, fishing activity attributes, job satisfaction, and individual and social attributes. Relationships between community context and differences in job satisfaction in the Northeast and Alaska regions confirmed that these factors, also included in the HIA model, are important aspects of impact assessment. Results help to show that changes in ocean governance have impacts on the human communities who use these important resources. To anticipate and ameliorate potential impacts on human well-being as indicated by tools such as the HIA model, research needs to be accomplished to appropriately design and account for these impacts. 相似文献
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Application of water quality index for groundwater quality assessment: Thirumanimuttar sub-basin, Tamilnadu, India 总被引:8,自引:0,他引:8
M. Vasanthavigar K. Srinivasamoorthy K. Vijayaragavan R. Rajiv Ganthi S. Chidambaram P. Anandhan R. Manivannan S. Vasudevan 《Environmental monitoring and assessment》2010,171(1-4):595-609
An attempt has been made to understand the hydrogeochemical parameters to develop water quality index in Thirumanimuttar sub-basin. A total of 148 groundwater samples were collected and analyzed for major cations and anions. The domination of cations and anions was in the order of Na>Mg>Ca>K for cations and Cl>HCO3 >SO4 in anions. The hydrogeochemical facies indicate alkalis (Na and K) exceed alkaline earths (Ca and Mg) and strong acids (Cl and SO4) exceed weak acid (HCO3). Water quality index rating was calculated to quantify overall water quality for human consumption. The PRM samples exhibit poor quality in greater percentage when compared with POM due to effective leaching of ions, over exploitation of groundwater, direct discharge of effluents and agricultural impact. The overlay of WQI with chloride and EC correspond to the same locations indicating the poor quality of groundwater in the study area. SAR, Na%, and TH were noted higher during both the seasons indicating most of the groundwater locations not suitable for irrigation purposes. 相似文献
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Water quality assessment is an important basic work in the development, utilization, management, and protection of water resources, and also a prerequisite for water safety. In this paper, the harmony degree equation (HDE) was introduced into the research of water quality assessment, and a new method for water quality assessment was proposed according to the HDE: by harmony degree equation (WQA-HDE). First of all, the calculation steps and ideas of this method were described in detail, and then, this method with some other important methods of water quality assessment (single factor assessment method, mean-type comprehensive index assessment method, and multi-level gray correlation assessment method) were used to assess the water quality of the Shaying River (the largest tributary of the Huaihe in China). For this purpose, 2 years (2013–2014) dataset of nine water quality variables covering seven monitoring sites, and approximately 189 observations were used to compare and analyze the characteristics and advantages of the new method. The results showed that the calculation steps of WQA-HDE are similar to the comprehensive assessment method, and WQA-HDE is more operational comparing with the results of other water quality assessment methods. In addition, this new method shows good flexibility by setting the judgment criteria value HD0 of water quality; when HD0?=?0.8, the results are closer to reality, and more realistic and reliable. Particularly, when HD0?=?1, the results of WQA-HDE are consistent with the single factor assessment method, both methods are subject to the most stringent “one vote veto” judgment condition. So, WQA-HDE is a composite method that combines the single factor assessment and comprehensive assessment. This research not only broadens the research field of theoretical method system of harmony theory but also promotes the unity of water quality assessment method and can be used for reference in other comprehensive assessment. 相似文献
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R. Veeningen 《Environmental monitoring and assessment》1983,3(3-4):321-330
This study deals with the use of the dynamics of dissolved oxygen concentration for water quality assessment in polder ditches. The dynamics of the dissolved oxygen concentration, i.e. the temporal and spatial variations in a few polder ditches under a range of natural, pollution and management conditions is presented. Five requisites formulated for the water quality indicator are discussed: (1) its relation with water quality goals, (2) nature and amount of information it provides, (3) if it could be standardized, (4) if it could be manipulated and (5) its measurability. 相似文献
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A. M. Sheela J. Letha K. Swarnalatha K. V. Baiju Divya Sankar 《Environmental monitoring and assessment》2014,186(5):3221-3237
Water pollution is one of the most critical problems affecting mankind. Weather pattern and land use of catchment area have significant role in quality of water bodies. Due to climate change, there is frequent variation in weather pattern all over the world. There is also rapid change in land use due to increase in population and urbanization. The study was carried out to analyze the effect of change in weather pattern during the monsoon periods of 2008 and 2012 on water quality of a tropical coastal lake system. The nature and extent of variation in different water quality parameters namely electrical conductivity (EC), magnesium (Mg), sodium (Na), chloride (Cl), sulphate (SO4), turbidity, Secchi disk depth, biochemical oxygen demand (BOD), phosphate (PO4), calcium (Ca), and water temperature as well as the effect of various land use activities in the lake basin on water quality have also been studied. There is significant reduction in precipitation, EC, Mg, Na, Cl, SO4, turbidity, and Secchi disk depths whereas a significant rise in the BOD, PO4, Ca, and water temperature were observed in 2012. This significant reduction in electrical conductivity during 2012 revealed that because of less precipitation, the lake was separated from the sea by the sandbar during most of the monsoon period and thereby interrupted the natural flushing process. This caused the accumulation of organic matter including phosphate and thereby resulting reduction in clarity and chlorophyll-a (algae) in the lake. The unsustainable development activities of Thiruvanathapuram city are mainly responsible for the degradation of water bodies. The lack of maintenance and augmentation activities namely replacement of old pipes and periodical cleaning of pipe lines of the old sewer system in the city results in the bypass of sewage into water bodies. Because of the existence of the old sewerage system, no effort has been taken by the individual establishment/house of the city to provide their own treatment system for sewage and sullage and the untreated wastes are discharged into these old sewer pipes and ultimately the wastes reach the water bodies. In this context, decentralized treatment of sewage, sullage, and garbage by individual houses/establishments/hotels/hospitals is a better option for the developing countries. With the rapid developmental activities, and due to the variation of precipitation due to climate change, it is highly essential to provide proper waste treatment/augmentation facilities in urban lake system because a slight variation in the weather pattern can result in serious implications in the already polluted water bodies. 相似文献
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Danuta Barałkiewicz Maria Chudzińska Barbara Szpakowska Dariusz Świerk Ryszard Gołdyn Renata Dondajewska 《Environmental monitoring and assessment》2014,186(10):6789-6803
We studied the effect of storm water drained by the sewerage system and discharged into a river and a small reservoir, on the example of five catchments located within the boundaries of the city of Poznań (Poland). These catchments differed both in terms of their surface area and land use (single- and multi-family housing, industrial areas). The aim of the analyses was to explain to what extent pollutants found in storm water runoff from the studied catchments affected the quality of surface waters and whether it threatened the aquatic organisms. Only some of the 14 studied variables and 22 chemical elements were important for the water quality of the river, i.e., pH, TSS, rain intensity, temperature, conductivity, dissolved oxygen, organic matter content, Al, Cu, Pb, Zn, Fe, Cd, Ni, Se, and Tl. The most serious threat to biota in the receiver came from the copper contamination of storm water runoff. Of all samples below the sewerage outflow, 74 % exceeded the mean acute value for Daphnia species. Some of them exceeded safe concentrations for other aquatic organisms. Only the outlet from the industrial area with the highest impervious surface had a substantial influence on the water quality of the river. A reservoir situated in the river course had an important influence on the elimination of storm water pollution, despite the very short residence time of its water. 相似文献