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141.
Natural hazards cause great damage to humankind and the surrounding ecosystem. They can cast certain indelible changes on the natural system. One such tsunami event occurred on 26 December 2004 and caused serious damage to the environment, including deterioration of groundwater quality. This study addresses the groundwater quality variation before and after the tsunami from Pumpuhar to Portnova in Tamil Nadu coast using geochemical methods. As a part of a separate Ph.D. study on the salinity of groundwater from Pondicherry to Velankanni, water quality of this region was studied with the collection of samples during November 2004, which indicated that shallow aquifers were not contaminated by sea water in certain locations. These locations were targeted for post-tsunami sample collection during the months of January, March and August 2005 from shallow aquifers. Significant physical mixing (confirmed with mixing models) within the aquifer occurred during January 2005, followed by precipitation of salts in March and complete leaching and dissolution of these salts in the post-monsoon season of August. As a result, maximum impact of tsunami water was observed in August after the onset of monsoon. Tsunami water inundated inland water bodies and topographic lows where it remained stagnant, especially in the near-shore regions. Maximum tsunami inundation occurred along the fluvial distributary channels, and it was accelerated by topography to a certain extent where the southern part of the study area has a gentler bathymetry than the north.  相似文献   
142.
Delta-aminolevulinate dehydratase (ALAD) activity has been used in prokaryotes and eukaryotes as a biomarker for environmental lead (Pb) exposure and toxicity. Microorganisms are sensitive indicators of toxicity at the fundamental level of ecological organization, but bacterial biomarker studies are focused on the Pseudomonas strains in Group I and E coli. The objectives of the present work were to determine if Burkholderia gladioli belonging to group II, due to its 16SrRNA similarity, can be used as biomarker in metal contamination and compare its possible usage with Pseudomonas aeruginosa and Citrobacter freundii (previously known as Esherichia freundii) and Bacterium freundii which are classified in Group I. In this study, ALAD activity in an environmental strains of Burkholderia gladioli, Pseudomonas aeruginosa, Citrobacter freundii were investigated to evaluate potential inhibition by Pb and other toxic metals. When the ALAD activity of Burkholderia gladioli was tested, Co and Pb decreased activity by 27 and 71%, respectively. In addition to these findings, Zn increased the activity up to 26%. These effects were found to be statistically meaningful (p < 0.05). It was determined that the increase of lead concentration inhibites the ALAD activity at each of the three strains. There was a statistically significant dose–response relationship between ALAD activity in cells of Burkholderia gladioli and Pb (Pearson correlation coefficent = −0.665; r 2 = 0.665, and p < 0.001). The strongest ALAD inhibition which was measured was 90% at Burkholderia gladioli when protein extracts were incubated with 750 μM of Pb. The relationship between Pb and ALAD activity was statistically described by [ALAD Activity] = 0.476−0.000597 × [Pb]. According to the obtained results, we suggest that the ALAD of Burkholderia gladioli can be used as a biomarker for lead contamination in the environment.  相似文献   
143.
The water bodies of Lucknow, Unnao and Kanpur (U.P.), India polluted through various point and non point sources were found to be either eutrophic or oligotrophic in nature. These water bodies supported a great number of algal diversity, which varied seasonally depending upon the physico-chemical properties of water. Further, the water bodies polluted through non point sources supports diverse algal species, while the water bodies polluted through point sources supports growth of tolerant blue green algae. High biomass producing algal species growing in these water bodies have accumulated significant amount of metals in their tissues. Maximum amount of Fe was found accumulated by species of Oedogonium sp. II (20,523.00 mug g(-1) dw) and Spirogyra sp. I (4,520.00 mug g(-1) dw), while maximum Chromium (Cr) was found accumulated in Phormedium bohneri (2,109.00 mug g(-1) dw) followed by Oscillatoria nigra (1,957.88 mug g(-1) dw) and Oedogonium sp. I (156.00 mug g(-1) dw) and Ni in Ulothrix sp. (495.00 mug g(-1) dw). Results showed that some of these forms growing in polluted environment and accumulating high amounts of toxic metals may be used as bioindicator species, however, their performance in metal contaminated water under different ecological niche is to be ascertained.  相似文献   
144.
The present study deals with the characterization of industrial effluents released from various industries and distribution of heavy metals in effluent discharge channel and its impact on the river Damodar. The effluent of tamlanala, a natural storm water channel, is extensively used for irrigation for growing vegetables in and around the study area. The heavy metals in water of the study area are in the order of Fe > Mn > Pb >?Cd and sediments follow similar trends too. The enrichment of heavy metals in the sediments are in the order of Cd (39.904) > Pb (33.156) > Mn (0.164) > Fe (0.013). The geoaccumulation index values reveal effluent channel is subjected to moderate to high pollution with respect to Cd (4.733) and Pb (4.466). The analyzed data for enrichment factors and the pollution load index (1.305) show that effluent channels have suffered from significant heavy metal contamination following industrialization and urbanization. Compared to baseline values, the surface sediment layers show high enrichment across the channel and at its discharge point. The factor analysis reveals three factors—industrial sources, surface runoff inputs, and background lithogenic factors which clarify the observed variance of the environmental variables. Metal pollution assessment of sediments suggests that pollution from the heavy metals observed is high in the tamlanala which in turn affects the downstream of the river system.  相似文献   
145.
The Hawkesbury–Nepean River (HNR) system in South-Eastern Australia is the main source of water supply for the Sydney Metropolitan area and is one of the more complex river systems due to the influence of urbanisation and other activities in the peri-urban landscape through which it flows. The long-term monitoring of river water quality is likely to suffer from data gaps due to funding cuts, changes in priority and related reasons. Nevertheless, we need to assess river health based on the available information. In this study, we demonstrated how the Factor Analysis (FA), Hierarchical Agglomerative Cluster Analysis (HACA) and Trend Analysis (TA) can be applied to evaluate long-term historic data sets. Six water quality parameters, viz., temperature, chlorophyll-a, dissolved oxygen, oxides of nitrogen, suspended solids and reactive silicates, measured at weekly intervals between 1985 and 2008 at 12 monitoring stations located along the 300 km length of the HNR system were evaluated to understand the human and natural influences on the river system in a peri-urban landscape. The application of FA extracted three latent factors which explained more than 70 % of the total variance of the data and related to the ‘bio-geographical’, ‘natural’ and ‘nutrient pollutant’ dimensions of the HNR system. The bio-geographical and nutrient pollution factors more likely related to the direct influence of changes and activities of peri-urban natures and accounted for approximately 50 % of variability in water quality. The application of HACA indicated two major clusters representing clean and polluted zones of the river. On the spatial scale, one cluster was represented by the upper and lower sections of the river (clean zone) and accounted for approximately 158 km of the river. The other cluster was represented by the middle section (polluted zone) with a length of approximately 98 km. Trend Analysis indicated how the point sources influence river water quality on spatio-temporal scales, taking into account the various effects of nutrient and other pollutant loads from sewerage effluents, agriculture and other point and non-point sources along the river and major tributaries of the HNR. Over the past 26 years, water temperature has significantly increased while suspended solids have significantly decreased (p?<?0.05). The analysis of water quality data through FA, HACA and TA helped to characterise the key sections and cluster the key water quality variables of the HNR system. The insights gained from this study have the potential to improve the effectiveness of river health-monitoring programs in terms of cost, time and effort, particularly in a peri-urban context.  相似文献   
146.
147.
The metal accumulation levels for muscle, skin, gill, liver and intestine tissues of some Cyprinidae species (Carassius carassius, Condrostoma nasus, Leuciscus cephalus and Alburnus alburnus) in Enne Dame Lake (Kütahya/Turkey), which is mostly fed by hot spring waters, were investigated. Analyses were performed for copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), cobalt (Co), magnesium (Mg), nickel (Ni), chrome (Cr) and boron (B) using inductively coupled plasma-optic emission spectroscopy (ICP-OES), and cadmium (Cd) using atomic absorption spectrophotometer (AAS) utilizing microwave digestion techniques. The concentrations of the heavy metals found in the fish varied in the follow ing ranges: Cu: < DL-7.04, Zn: 6.96-357.25, Mn: < DL-20.70, Ni: < DL-6.21, Fe: 9.62-2500.33, Cr: < DL-1.74, Co: < DL-0.54, Cd: 0.01-0.27 and Mg: 197.44-904.90 mg/kg wet weight. While B had the second highest concentration in the water of the lake, it was not encountered in any tissue of the investigated species. In all tissues and the species, While the bioaccumulation factors (BAFs) of Mn, Zn, Fe and Cu were remarkably high, the BAFs of Mg, Cr, Co, and B were also fairly low or none. Although the heavy metal accumulation levels for the muscle were generally lower than other tissues, there were some exceptions. Cd level in the muscle of C. carassius was higher than the permissible limit stated by Turkish legislation, FAO and WHO. The mean metal amounts for all the investigated tissues and species are statistically compared and discussed in this study.  相似文献   
148.
A new method for separation and preconcentration of trace amounts of Cu(II), Ni(II), Pb(II), Cd(II) and Mn(II) ions in various matrices was proposed. The method is based on the adsorption and chelation of the metal ions on a column containing Amberlite XAD-1180 resin impregnated with 1-(2-thiazolylazo)-2-naphthol (TAN) reagent prior to their determination by flame atomic absorption spectrometry (FAAS). The effect of pH, type, concentration and volume of eluent, sample volume, flow rates of sample and elution solutions, and interfering ions have been investigated. The optimum pH for simultaneous retention of all the metal ions was 9. Eluent for quantitative elution was 20 ml of 2 mol l(-1) HNO(3). The optimum sample and eluent flow rates were found as 4 ml min(-1), and also sample volume was 500 ml, except for Mn (87% recovery). The sorption capacity of the resin was found to be 0.77, 0.41, 0.57, and 0.30 mg g(-1) for Cu(II), Ni(II), Cd(II), and Mn(II), respectively. The preconcentration factor of the method was 200 for Cu(II), 150 for Pb(II), 100 for Cd(II) and Ni(II), and 50 for Mn(II). The recovery values for all of the metal ions were > or = 95% and relative standard deviations (RSDs) were < or = 5.1%. The detection limit values were in the range of 0.03 and 1.19 microg l(-1). The accuracy of the method was confirmed by analysing the certified reference materials (TMDA 54.4 fortified lake water and GBW 07605 tea samples) and the recovery studies. This procedure was applied to the determination of Cu(II), Ni(II), Pb(II), Cd(II) and Mn(II) in waste water and lake water samples.  相似文献   
149.
Recognition and understanding of landscape dynamics as a historical legacy of disturbances are necessary for sustainable management of forest ecosystems. This study analyzes spatial and temporal changes in land use and forest cover patterns in a typical mountain forest area in Rize Forest Enterprise of the Northeastern part of Turkey. The area is investigated by evaluated the temporal changes of spatial structure of forest conditions through spatial analysis of forest cover type maps from 1984 and 2007 using GIS and FRAGSTATS. The quantative evidences presented here showed that there were drastic changes in the temporal and spatial dynamics of land use/forest cover. As an overall change between 1984 and 2007, there was a net decrease of 2.30% in total forested areas. On one hand, productive forest areas decreased 12,506 ha, on the other hand, degraded forest areas increased 14,805 ha. In examining the changes of crown closure and development stages of forest ecosystem during the study period, the forest stand area with medium crown closures increased. Regenerated area increased while the other development stages were left to grow to mature development stages in the period. These results regarding to crown closure and development stage showed that forest quality has increased but total forest areas decreased. This is partially due to out-migration of rural population in Rize and Cayeli towns. In terms of spatial configuration, analysis of the metrics revealed that landscape structure in Study area had changed substantially over the 23-year study period, resulting in fragmentation of the landscape as indicated by the large patch numbers and the smaller mean patch sizes due to heavy timber subtraction, illegal cutting, and uncontrolled stand treatments.  相似文献   
150.
The environment is very important in terms of the behaviours and actions of human beings, and activity–environment correlation is used frequently in outdoor arrangements. The environment must meet the requirements and expectations of society. Outdoor activities are the activities that contribute to the well-being of human beings in physical (heartbeat, respiration, blood pressure, etc.) (Ulrich, Journal of Environmental Psychology 11:210–230, 1991), psychological (fear, anxiety, depression, loneliness, stress, etc.) (Marcus and Barnes 1999) and behavioural (insomnia, nervousness, restlessness, passivity, etc.) (Ulrich 1999) terms. It is known that human beings are affected significantly by the environments they are in, and more importantly, it is known that the environment they are in affects their happiness status. The causes of this effect are the features and appearances of the spatial elements and components that mainly make up such environments. One of the elements that is used frequently in landscape is water. If one examines designed or natural open spaces, it may be observed that water has very distinctive features. Dynamic (in the form of a leak, with intense flow rate, cascade, foamy, squirting, jet, graded, etc.) and still water elements may be used with sculptures, plants, rocks and elevations (on land). This study aims to reveal which age groups of students enjoy the different types of activities with regards to water features and emotional associations that motion and characteristics of water bring out in human beings and also to reveal the water preferences of human beings, including their reasons for such preference. Thus, 20 different water compositions located in Edirne Province were selected, and in 2-min camera reels, the students of various age groups assessed water with various characteristic features via a survey. As a result, it was revealed that human beings from various age groups wish to perform different activities with water elements having distinctive characteristic features, and the types of water elements that are subject to various age groups’ like and dislike were determined. Kruskal–Wallis test was used during testing the effect of age differences. Chi-square analysis was used in order to examine the effect of age differences on preferences with regards to the activities that shall be performed at locations that include utilization of various water elements. The results reveal that while the use of water should be allowed in landscaping, selections regarding the elements of these water features should be made based on the type of activity and the age group of users in relation to the location.  相似文献   
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