共查询到20条相似文献,搜索用时 15 毫秒
1.
Bashir W McGovern F O'Brien P Ryan M Burke L Paull B 《Journal of environmental monitoring : JEM》2008,10(6):730-738
A major Irish study, based upon more than 8000 samples collected over the measurement period of 22 years, for sulfur dioxide (SO2-S), sulfate (SO4-S) and nitrogen dioxide (NO2-N) concentrations (microg m(-3)) within air, and the ionic composition of precipitation samples based on sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), chloride (Cl-), sulfate (SO4-S), non-sea salt sulfate (nssSO4-S), ammonium (NH4-N), and nitrate (NO3-N) weighted mean concentrations (mg l(-1)), has been completed. For the air samples, the sulfur dioxide and sulfate concentrations decreased over the sampling period (1980-2004) by 75% and 45%, respectively, whereas no significant trend was observed for nitrogen dioxide. The highest concentrations for sulfur dioxide, sulfate and nitrogen dioxide were associated with wind originating from the easterly and northeasterly directions i.e. those influenced by Irish and European sources. The lowest concentrations were associated with the westerly directions i.e. for air masses originating in the North Atlantic region. This was further verified with the use of backward (back) trajectory analysis, which allowed tracing the movement of air parcels using the European Centre for Medium range Weather Forecasting (ECMWF) ERA-40 re-analysis data. High non-sea salt sulfate levels were being associated with air masses originating from Europe (easterlies) with lower levels from the Atlantic (westerlies). With the precipitation data, analysis of the non-sea salt sulfate concentrations showed a decrease by 47% since the measurements commenced. 相似文献
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The ungauged wet semi-arid watershed cluster, Seethagondi, lies in the Adilabad district of Telangana in India and is prone to severe erosion and water scarcity. The runoff and soil loss data at watershed, catchment, and field level are necessary for planning soil and water conservation interventions. In this study, an attempt was made to develop a spatial soil loss estimation model for Seethagondi cluster using RUSLE coupled with ARCGIS and was used to estimate the soil loss spatially and temporally. The daily rainfall data of Aphrodite for the period from 1951 to 2007 was used, and the annual rainfall varied from 508 to 1351 mm with a mean annual rainfall of 950 mm and a mean erosivity of 6789 MJ mm ha?1 h?1 year?1. Considerable variation in land use land cover especially in crop land and fallow land was observed during normal and drought years, and corresponding variation in the erosivity, C factor, and soil loss was also noted. The mean value of C factor derived from NDVI for crop land was 0.42 and 0.22 in normal year and drought years, respectively. The topography is undulating and major portion of the cluster has slope less than 10°, and 85.3 % of the cluster has soil loss below 20 t ha?1 year?1. The soil loss from crop land varied from 2.9 to 3.6 t ha?1 year?1 in low rainfall years to 31.8 to 34.7 t ha?1 year?1 in high rainfall years with a mean annual soil loss of 12.2 t ha?1 year?1. The soil loss from crop land was higher in the month of August with an annual soil loss of 13.1 and 2.9 t ha?1 year?1 in normal and drought year, respectively. Based on the soil loss in a normal year, the interventions recommended for 85.3 % of area of the watershed includes agronomic measures such as contour cultivation, graded bunds, strip cropping, mixed cropping, crop rotations, mulching, summer plowing, vegetative bunds, agri-horticultural system, and management practices such as broad bed furrow, raised sunken beds, and harvesting available water using farm ponds and percolation tanks. This methodology can be adopted for estimating the soil loss from similar ungauged watersheds with deficient data and for planning suitable soil and water conservation interventions for the sustainable management of the watersheds. 相似文献
3.
A. Giriraj M. S. R. Murthy C. Beierkuhnlein 《Environmental monitoring and assessment》2010,161(1-4):29-44
A majority of the research on forest fragmentation is primarily focused on animal groups rather than on tree communities because of the complex structural and functional behavior of the latter. In this study, we show that forest fragmentation provokes surprisingly rapid and profound alterations in tropical tree community. We examine forest fragments in the tropical region using high-resolution satellite imagery taken between 1973 and 2004 in the Southern Western Ghats (India) in relation to landscape patterns and phytosociological datasets. We have distinguished fragmentation in six categories—interior, perforated, edge, transitional, patch, and undetermined—around each forested pixel. Furthermore, we have characterized each of the fragment class in the evergreen and semi-evergreen forest in terms of its species composition and richness, its species similarity and abundance, and its regeneration status. Different landscape metrics have been used to infer patterns of land-use changes. Contiguous patches of >1,000 ha covered 90% of evergreen forest in 1973 with less porosity and minimal plantation and anthropogenic pressures; whereas in 2004, the area had 67% forest coverage and a high level of porosity, possibly due to Ochlandra spread and increased plantations which resulted in the loss of such contiguous patches. Results highlight the importance of landscape metrics in monitoring land-cover change over time. Our main conclusion was to develop an approach, which combines information regarding land cover, degree of fragmentation, and phytosociological inputs, to conserve and prioritize tropical ecosystems. 相似文献
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An assessment of the chemical composition of precipitation and throughfall in rural-industrial gradient in wet subtropics (southern Brazil) 总被引:2,自引:0,他引:2
Casartelli MR Mirlean N Peralba MC Barrionuevo S Gómez-Rey MX Madeira M 《Environmental monitoring and assessment》2008,144(1-3):105-116
The chemical composition of bulk precipitation and throughfall were analyzed, during a 1-year period (2002), in rural-urban-industry gradients with similar forest cover (Eucalyptus spp.) in southern Brazil (Rio Grande and Porto Alegre cities). Values of pH varied from 5.0-5.1 in rural to 5.4-6.1 in industrial sites, and were intermediate in urban sites. The major ions in bulk precipitation were Na(+), Cl(-), [Formula: see text], [Formula: see text] and [Formula: see text], and concentrations increased in urban and industrial sites. Principal component analysis identified the local main anthropogenic sources. Estimated annual amounts of dry deposition were generally greater in both industrial and urban sites than in rural sites. Areas close to industrial activity showed greater S and N total deposition (10.4-10.9 and 20.2-30.6 kg/ha, respectively) than in urban (3.4-7.3 and 14.6-24.1 kg/ha) and in rural (1.7-2.6 and 8.9-12.1 kg/ha) sites. Annual deposition of Ca and P varied from 0.6 and 3.0 kg/ha in rural to 45.4 and 32.4 kg/ha in industrial sites, maximum values being observed closed to the phosphate fertilizer plant of Rio Grande. Deposition in urban and industrial sites may be balanced by the alkaline cations, as bulk precipitation pH varied from 5.4 to 6.1, and was greater than in rural sites (5.0-5.1). 相似文献
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Qiaohong Sun Dongxian Kong Chiyuan Miao Qingyun Duan Tiantian Yang Aizhong Ye Zhenhua Di Wei Gong 《Environmental monitoring and assessment》2014,186(9):5663-5679
Climate change has impacts on both natural and human systems. Accurate information regarding variations in precipitation and temperature is essential for identifying and understanding these potential impacts. This research applied Mann–Kendall, rescaled range analysis and wave transform methods to analyze the trends and periodic properties of global and regional surface air temperature (SAT) and precipitation (PR) over the period of 1948 to 2010. The results show that 65.34 % of the area studied exhibits significant warming trends (p?<?0.05) while only 3.18 % of the area exhibits significant cooling trends. The greatest warming trends are observed in Antarctica (0.32 °C per decade) and Middle Africa (0.21 °C per decade). Notably, 62.26 % of the area became wetter, while 22.01 % of the area shows drying trends. Northern Europe shows the largest precipitation increase, 12.49 mm per decade. Western Africa shows the fastest drying, ?21.05 mm per decade. The rescaled range analysis reveals large areas that show persistent warming trends; this behavior in SAT is more obvious than that in PR. Wave transform results show that a 1-year period of SAT variation dominates in all regions, while inconsistent 0.5-year bands are observed in East Asia, Middle Africa, and Southeast Asia. In PR, significant power in the wavelet power spectrum at a 1-year period was observed in 17 regions, i.e., in all regions studied except Western Europe, where precipitation is instead characterized by 0.5-year and 0.25-year periods. Overall, the variations in SAT and PR can be consistent with the combined impacts of natural and anthropogenic factors, such as atmospheric concentrations of greenhouse gases, the internal variability of climate system, and volcanic eruptions. 相似文献
9.
Vegetation NDVI Linked to Temperature and Precipitation in the Upper Catchments of Yellow River 总被引:3,自引:0,他引:3
Fanghua Hao Xuan Zhang Wei Ouyang Andrew K. Skidmore A. G. Toxopeus 《Environmental Modeling and Assessment》2012,17(4):389-398
Vegetation in the upper catchment of Yellow River is critical for the ecological stability of the whole watershed. The dominant vegetation cover types in this region are grassland and forest, which can strongly influence the eco-environmental status of the whole watershed. The normalized difference vegetation index (NDVI) for grassland and forest has been calculated and its daily correlation models were deduced by Moderate Resolution Imaging Spectroradiometer products on 12 dates in 2000, 2003, and 2006. The responses of the NDVI values with the inter-annual grassland and forest to three climatic indices (i.e., yearly precipitation and highest and lowest temperature) were analyzed showing that, except for the lowest temperature, the yearly precipitation and highest temperature had close correlations with the NDVI values of the two vegetation communities. The value of correlation coefficients ranged from 0.815 to 0.951 (p?<?0.01). Furthermore, the interactions of NDVI values of vegetation with the climatic indicators at monthly interval were analyzed. The NDVI of vegetation and three climatic indices had strong positive correlations (larger than 0.733, p?<?0.01). The monthly correlations also provided the threshold values for the three climatic indictors, to be used for simulating vegetation growth grassland under different climate features, which is essential for the assessment of the vegetation growth and for regional environmental management. 相似文献
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Dubravka Relić Dragana Đorđević Sanja Sakan Ivan Anđelković Ana Pantelić Ratomir Stanković Aleksandar Popović 《Environmental monitoring and assessment》2013,185(9):7627-7645
In this paper, the main objective was fractionation of Cd, Cu, Ni, Pb, Zn, Ca, Fe, and K in certificate material and sediment samples gathered from and around the Petrochemical Industry using the conventional, microwave and ultrasonic sequential extraction. Microwave oven and ultrasound bath were used as an energy source for achieving faster extraction. Additional heating and boiling of samples were avoided by using lower power and shorter time for microwave and ultrasound extraction. Precision and accuracy of procedure were evaluated by using certificate material (BCR701). Acceptable accuracy of metals (87.0–111.3 %) was achieved for all three-step sequential of conventional extraction protocol. An accuracy of the fourth step has been verified with two certificate materials: BCR143R and 146R. The range of total extracted metal concentrations from sediments was similar for all three extraction techniques. A significant high percentage of Cd, Cu, and Zn were obtained after extraction of the exchangeable and acid soluble sediment fraction. Principal component analysis of values obtained after determination of risk assessment code using conventional and ultrasound sequential extraction show similarity of these values. Accuracy, recovery, and risk assessment code values imply that ultrasound sequential extraction is a more suitable, accelerated sequential extraction procedure (30 min per extraction step) than microwave extraction in applied conditions. 相似文献
11.
Chetan A. Gaonkar Venkat Krishnamurthy Arga Chandrashekar Anil 《Environmental monitoring and assessment》2010,168(1-4):179-194
Zooplankton abundance, biomass, and composition from the ports of Mumbai, India, were studied by selecting 14 stations in and around the area during three different periods between 2001 and 2002 (Nov 01, Apr 02, and Oct 02). The results are compared with the records available since the 1940s. Copepod species such as Canthocalanus sp., Paracalanus arabiensis, Cosmocalanus sp., Euterpina acutifrons, Nannocalanus minor, and Tortanus sp. which were not reported in the earlier studies were observed during the present investigation. Purely herbivorous forms like Nannocalanus minor, Paracalanus sp., and Temora discaudata were in reduced abundance during Apr 02 sampling which was coupled with reduction in the diatom population. Whereas increased abundance of some carnivorous and omnivorous forms during Apr 02 sampling can be related to the changes in the food web dynamics. 相似文献
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The biomonitoring properties of oak tree bark compared with the epiphytic moss Hypnum cupressiforme and the influence of the tree bark, as its growth substrate, on the content of heavy metals in moss were investigated. Samples of the epiphytic moss H. cupressiforme and oak tree bark (Quercus spp.) were collected in Eastern Romania at a total of 44 sampling sites. Parallel moss and bark samples were collected from the same sides of the trunk circumference. V, Cr, Ni, Cu, Zn, As, Mo, Cd, In, Tl, Sn, Pb, and Bi were determined by ICP-MS. Principal component analysis was used to identify possible sources of metals in bark and moss. Six factors explaining 87 % of the total variance in the data set were chosen. The main factors represent long-range atmospheric transport of elements (Zn, Cd, (Pb), Bi, (Mo), (Tl)), local emissions from industrial sources (As, Cr, Ni, V), road traffic (Pb, Zn) and agricultural activities (Cu, (Zn)). The element concentrations in moss and bark samples are of the same order of magnitude. For almost all the elements, higher concentrations were obtained in moss. Significant correlations between concentrations in moss and bark samples were obtained for 7 of the 13 elements: V, Ni, Cu, Zn, Cd, In, and Bi, all typical anthropogenic pollutants. The use of tree bark for monitoring purposes might be an alternative in areas where there is a scarcity of mosses. 相似文献
14.
V. M. León C. Martínez-Gómez I. García J. A. Campillo J. Benedicto 《Environmental monitoring and assessment》2013,185(2):1055-1070
Polycyclic aromatic hydrocarbons (PAHs) have been determined in blue mussels (Mytilus galloprovincialis) from several Iberian Mediterranean coastal areas through the implementation of a monitoring programme from Spain in the framework of the Mediterranean Pollution Programme (MED POL). The selected areas correspond to sites with differing degrees of exposure to the main pollution sources (hot spots, coastal and reference areas). The sampling campaigns were performed from 2004 to 2009, with samples being taken from May to June, the non-spawning period for mussels in this area. Thirteen PAHs were determined by high-performance liquid chromatography with specific fluorescence detection. In general, total PAHs concentration was lower than 50 μg kg?1 d.w., except in areas close to the principal ports and cities (Barcelona, Tarragona, Valencia and Algeciras) where it varies from 75 to 390 μg kg?1 d.w. Background concentrations have been proposed for PAHs in mussels (23.8 μg kg?1 d.w.) from Western Mediterranean area. Temporal trends were not statistically significant for PAHs concentrations from 2004 to 2009. Longer monitoring periods would be required to detect a continuous tendency, especially for PAHs because although the efficiency of combustion engines has reduced PAHs emissions, their increasing use could alter this potential reduction. The predominant PAHs were three and four ring congeners in all cases, with the predominance of phenanthrene in mussels sited far from the main PAHs sources. The phenanthrene/anthracene (lower than 10) and fluoranthene/pyrene (higher than 1) ratios indicate that PAHs detected in Spanish Mediterranean coastal mussels are mainly of pyrolytic origin. 相似文献
15.
Bondareva L 《Environmental monitoring and assessment》2012,184(6):3831-3847
Discharges from the Mining-and-Chemical Combine (MCC) of Rosatom, downstream from Krasnoyarsk, resulted in radioactive contamination
of sediments of the River Yenisei. The concentration of artificial gamma-emitting radionuclides (137Cs, 60Co, 152Eu, and 241Am) was determined with the objective to analyze the migration processes leading to the transport of these radionuclides.
The content of artificial radionuclides in the surface layers of the study area varied in wide ranges: 137Cs—318–1,800 Bq/kg, 60Co—87–720 Bq/kg, 152Eu—12–287 Bq/kg and 241Am—6–76 Bq/kg. There was a sequence of migration of radionuclides investigated in the surface layer of sediments that were
collected in the near zone of influence of the MCC: 241Am ≈ 152Eu > 60Co > 137Cs. Radionuclide species have been found to be directly related to sediment structure and composition. 相似文献
16.
Portable X-ray fluorescence (XRF) technology may provide faster turn-around without compromising accuracy when assessing personal exposures to metals such as lead, but it has only been tested in limited field environments. This study is part of a series, where different sampler types are used to collect airborne lead in different environments for presentation to a portable XRF analyzer. In this case personal samples were taken at a bronze foundry where lead is added to an alloy of copper, zinc and iron to improve casting, using the closed-face 37 mm cassette, the 37 mm GSP or "cone" sampler, the 25 mm Institute of Occupational Medicine (IOM) inhalable sampler, the 25 mm Button sampler, and the open-face 25 mm cassette. Mixed cellulose-ester filters were used in all samplers. Following XRF analysis the samples were extracted with acid and analyzed by inductively coupled plasma optical emission spectroscopy (ICP). For lead, all five samplers gave correlations (r(2)) greater than 0.9 between the two analytical methods over the entire range of found lead mass, which encompassed both the action level and the permissible exposure limit enforced in the USA by the Occupational Safety and Health Administration (OSHA). However, a correction was required to adjust linear regression trendlines to give a 1 : 1 correlation for the average of three readings across the GSP sampler, and a similar correction was required for the single readings from the IOM sampler and the 25 mm filter cassette. The bias possibly is due to interference from other metals, possibly copper which can absorb the fluorescent radiation of lead. In the case of the Button sampler, the bias is larger, indicating a further source of error, perhaps due to the thickness of the deposit. However, in all cases, correction of the lead results did not greatly affect the overall percentage of samples where the XRF result was within 25% of the ICP result, although it did improve the overall accuracy of the results. The GSP, IOM and Button samplers are suitable candidates for further evaluation as compatible with on-site XRF analysis for lead and other metals. It is important to check carefully factory pre-set instrument calibrations, as a bias in the calibration for copper was observed. 相似文献
17.
Determination of Pb and Cd in road dusts over the period in which Pb was removed from petrol in the UK 总被引:1,自引:0,他引:1
It is commonly agreed that automobile exhaust has been the most important source of Pb pollution in urban areas, and that Cd may come from wear and tear of tyres. This study evaluates the fall in Pb concentrations in road dusts in Manchester as a consequence of the removal of Pb from petrol in January 2000. In the work presented here a slurry graphite furnace atomic absorption methodology for the determination of Pb and Cd in road dusts has been developed and is compared with an acid digestion method in terms of efficiency. The reproducibility and accuracy of the results obtained by acid digestion and the slurry method have been studied and a certified reference material CRM 038 was analysed to confirm the reliability of the proposed methods. Different factors were evaluated throughout this work including: (i) the effect of traffic density on Pb and Cd levels in road dust samples collected weekly during the period of May 1999 until September 2000; (ii) comparison between the Pb and Cd levels in a busy road and a residential street; (iii) the effect of distance from the source on Pb and Cd levels; The results of these experiments show a reduction in Pb levels over the sampling period. The relationship between road dust particle size and Pb and Cd concentration was also investigated in the 4-250 microns size range using the slurry method, showing that there is a relationship between metal concentration and particle size; the highest concentrations being for the smallest particle size. 相似文献
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Furuta N Iijima A Kambe A Sakai K Sato K 《Journal of environmental monitoring : JEM》2005,7(12):1155-1161
APM was collected and trace elements existing in the particles were monitored since May 1995 in this study. APM sample was collected separately by size (d < 2 microm, 2-11 microm and >11 microm) on the roof of the university building (45 m above ground) in the campus of Faculty of Science and Engineering, Chuo University, Tokyo, Japan, using an Anderson low volume air sampler. The collected sample was digested by HNO3, H2O2 and HF using a microwave oven, and major elements (Na, Mg, Al, K, Ca and Fe) were measured by ICP-AES, and trace elements (Li, Be, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba and Pb) were measured by ICP-MS. It was observed that the APM concentration was higher between the winter and the spring, compared to during the summer. The enrichment factor was calculated for each element in each set of APM (d < 2 microm, 2-11 microm and >11 microm). Seasonal trends of enrichment factors were examined, and the elements were classified into 3 groups according to the common seasonal behavior. It is likely that the elements in the same group have common origins. Toxic pollutant elements (Sb, Se, Cd, Pb and As) were found in small particles with d of <2 microm in concentrated levels. Antimony (Sb) had the highest enrichment factor, and the results suggested that Sb level in APM was extremely high. The origins of Sb were sought, and wastes from plastic incineration and brake pad wears of automobiles were suspected. Each set of APM (d < 2 microm, 2-11 microm and >11 microm) was classified by the shape, and the shape-dependent constituents of a single APM particle were quantitatively measured by SEM-EDX. High concentration of Sb was found in APM <2 microm and square particles. Particles less than 2 microm and square shaped particles were major particles produced by actual car braking experiments. From these experimental results it was concluded that the source of Sb in squared APM <2 microm is considered to be from brake pad wear. 相似文献
19.
Gebbink WA Letcher RJ Hebert CE Chip Weseloh DV 《Journal of environmental monitoring : JEM》2011,13(12):3365-3372
In this study, temporal trends and patterns of major C(4) to C(15) chain length PFCAs and PFSAs and some sulfonamide, fluorotelomer acid and alcohol precursors were determined in herring gull (Larus argentatus) egg pools. Samples were analyzed from fifteen collection years including 1990 and all years from 1997 to 2010, and from seven colonies located throughout the Great Lakes, ranging from remote to highly urbanized areas. Other than at the Toronto Harbour colony, the slopes of ∑PFSA concentrations (C(6), C(8), and C(10)) versus time were negative indicating general declines between 1990 and 2010. PFOS was the dominant PFSA regardless of colony or year, ranging from 80 to 99% of ∑PFSA. For ∑PFCA (C(8)-C(15)), slopes of concentrations versus time were generally positive with 4 of 7 colonies showing statistically significant (p < 0.05) increases in levels through time. Individual PFCAs showed similar increasing trends except for PFOA. Regardless of colony, the PFCA pattern was dominated by the C(10) to C(13) PFCAs. Consistent with the PFOS declines, concentrations of the PFOS precursor, PFOSA, declined at most colonies between 1990 and 2006 and post-2006 concentrations were below detection limits. Declining concentrations of the C(8) PFCs, PFOS, PFOA and PFOSA, were consistent with the phase out in 2002 by the 3M Company in North America of all of C(8) PFC-related chemistry products. Increasing production volumes of fluorotelomer based compounds, and degradation of these compounds to PFCAs may explain increasing trends of PFCAs in gull eggs. Dietary changes as measured by carbon and nitrogen stable isotopes, showed minimal relationships to PFC levels in gull eggs, which indicates the complexity of aquatic and terrestrial food of gulls and sources of PFCs. 相似文献
20.
Daniel Cluis Claude Langlois Raymond van Coillie Claude Laberge 《Environmental monitoring and assessment》1989,13(2-3):429-441
Despite the considerable amount of effort and resources involved in monitoring water quality, water quality assessment and environmental follow-up are sometimes carried out with simple statistics, the main reason being the lack of appropriate statistical methods adapted to the nature of sampled water quality data.A survey of the classical methods used for trend detection and of their limitations is first presented, including the most recent non-parametric techniques adapted to the structure of the sampled data and to the possible types of trends occuring. This paper then presents an interactive user-friendly software package developed for microcomputers making use of these latest adapted techniques. Afterwards, some applications of the software are described pertaining to the concentrations measured at long-term stations on the St. Lawrence River and to the mass loadings discharged by regulated industries. Finally, conclusions are drawn about the assumptions, performance and limitations of the package as well as about the research needs to improve the usefulness and applicability of the software. 相似文献