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1.
In this article the consistency of forest damageassessments on conifer trees is analysed, by usingdifferent methods in estimating the accuracy inassessments of defoliation and discolouration. The dataoriginate from control surveys in the Swedish nationalforest damage survey, as well as from national andinternational training courses. Standard deviation ofdifferences in the assessment of defoliation on singletrees is found to be about 10% units for Norway spruceand 8.5% for Scots pine. Problems in correctly assessingdamaged Scots pine trees and discoloured Norway sprucetrees are revealed by measures of agreement (Kappastatistic). Results from several years of nationaltraining courses indicate that, on an average, theobserver teams do not significantly differ from a nationalstandard, but significant differences between observerteams are found. The presented estimates indicate asubstantial within observer error compared to the betweenobserver error. The results indicate that the long-termdevelopment of forest damage, rather than short-termfluctuations, is the most important information fromthese kinds of inventories.  相似文献   

2.
In recent years, central environmental protection inspection (CEPI) has been a major policy innovation in the field of Chinese environmental governance. Based on panel data on the daily air quality of Chinese cities, this paper mainly uses a difference-in-differences (DID) approach to conduct an empirical analysis of the relationship between CEPI and the air quality governance performance of Chinese local governments. There are large differences in the impact of CEPI on different air quality indicators. Controlling for a series of variables, we found that CEPI significantly reduced the air quality index (AQI) and concentrations of pollutants including PM2.5, PM10, SO2 and NO2 and that it significantly increased the concentration of O3; however, it had no significant effect on the concentration of CO. Furthermore, we complemented the quantitative analyses with qualitative evidence gathered from an in-depth interview. Based on the qualitative evidence collected, CEPI indeed plays a role in improving the environmental protection performance of regular environmental governance. Notably, CEPI achieved better and sustainable results in improving air quality through the underlying mechanism of promoting regular governance by campaign-oriented governance in the internal hierarchical system. This article not only provides a marginal empirical contribution by providing new quantitative evidence but also helps reveal the underlying mechanism of promoting regular governance.  相似文献   

3.
Spatiotemporal shifts in the extent and distribution of alpine wetland ecosystems in China's Qinghai-Tibet plateau were investigated for the period 1967-2004. Using aerial photographs for 1967, and satellite remote sensing data for 1986, 2000, and 2004/5, the main components and distribution of alpine wetland ecosystems in the headwaters regions of the Yangtze and Yellow Rivers, as well as those of the nearby Zoige region, were analyzed. Widespread degradation of the Qinghai-Tibet plateau's alpine wetlands occurred between 1967 and 2004, with over 10% of their area being lost. The greatest such degradation occurred in the headwaters region of Yangtze River, where wetland areas shrank by 29%, and the area of dried-up lakes rose by 17.5%. In the Yellow River's headwaters region as well as the Zoige region, wetland ecosystems clearly underwent accelerated fragmentation and isolation in their spatial distribution. The wetlands' degradation was closely correlated to the rise in air temperature, which from 1982-2004 was over 2-fold faster that from 1965-1982.  相似文献   

4.
A detailed field and laboratory study on small 0.84-ha test site of agricultural land near Sofia (Bulgaria) has been carried out in order to test the applicability of magnetic methods in soil erosion estimation in the particular case of strongly magnetic parent material. Field measurements of magnetic susceptibility were carried out with grid size of 6 m, resulting in 258 data points. Bulk soil material was gathered from 78 grid points. Natural, non-disturbed soil section was sampled near the agricultural field for reference profile of complete undisturbed soil. Surface susceptibility measurements reveal well-defined maxima down slope which, however, cannot be assigned directly to a certain depth interval, corresponding with susceptibilities along the non-disturbed soil profile. This is caused by the high magnetic susceptibility of the lithogenic coarse-grained magnetic fraction. Non-uniqueness is resolved by using magnetic susceptibility of coarse (1 mm >?d?> 63 μm) and fine (d < 63 μm) mechanical fractions and the parameter Δχ = 100*(χ coarse???χ fine)/χ bulk (%). It shows increased values in the C-horizon of undisturbed soil profile, which corresponds to a certain part of the studied area. After the application of an empirical model to predict the values of magnetic parameter after tillage homogenization and removal of soil material from the surface, the amount of soil loss is estimated.  相似文献   

5.
6.
Accelerated eutrophication of surface water is often caused by high phosphorus (P) losses from agricultural fields. Long-term measurements of P concentrations from arable fields are therefore important for understanding of processes and key factors behind losses. Unfortunately, long-time series are difficult to compare due to high variablity, non-normal distribution, precipitation variability and flow relatedness. The objective was to use locally weighted scatterplot smoothing (LOWESS) and Seasonal Kendall Test to account for discharge effects on concentrations of P forms and suspended soil material, and to identify trends for seven agricultural fields included in a Swedish water quality monitoring program. Soil P content and sorption capacity governed concentrations and losses of dissolved reactive phosphorus (DRP). Other factors, such as preferential flow may influence the importance of these factors. Suspended soil material and unreactive phosphorus (UP) concentrations in water discharge depended on soil texture, slope of the field and total soil P content. Statistically significant trends in concentrations of different P forms were found for two fields. These trends are probably a consequence of changes in P additions and soils P saturation levels.  相似文献   

7.
The chemical speciation, fractionation and availability of mercury in sediments from a cinnabar mining area (Almadén, Spain) was studied with different extraction and analytical procedures, in order to determine the degree to which the ecosystem is harmed by this pollutant. Three total extraction procedures, a sequential extraction and the speciation of organo-mercury compounds were performed in nine sediment samples. In the study area, although concentrations of mercury can be extremely high (up to 1,000 mg kg(-1)), no organomercury compounds were detected (< 2 microg kg(-1) and the availability of this element seems restricted. One of the methods for total extraction presented considerably lower recovery in Almadén's sediments, yet the results were controlled with certified reference materials. This disagreement was attributed to the fact that the mercury is in a refractory form. Sequential extraction was able to show that most of the mercury is associated with sulfides (probably as metacinnabar) or in the residual refractory phase (probably as red cinnabar).  相似文献   

8.
The World Health Organization (WHO)/United Nations Children??s Fund (UNICEF) Joint Monitoring Programme (JMP) for Water Supply and Sanitation was designed to provide reference figures for access in individual countries to safe water. The JMP is based on non-administrative or nongovernment data from national-level surveys such as the Multiple Indicator Clusters Survey (MICS) or Demographic Health Survey. In the 2007 JMP report, India is noted to have water supply coverage of 89% (95% in urban areas and 85% in rural areas) compared to the Government of India estimates of 95%. The central state of Madhya Pradesh is noted by the Government of India to have coverage of 60%. However, the definition of access to safe water currently does not consider the quality or safety of the water being consumed. This paper, therefore, presents results from the application of a statistical tool (random multiple cluster technique??termed Rapid Assessment of Drinking Water Quality [RADWQ]) to Indore Zone in Madhya Pradesh. When results provided by the RADWQ technique are compared to the JMP MICS data, coverage levels reported in the JMP are reduced by up to 40% due to the high risk of microbiological (thermotolerant coliforms) contamination. In Indore Zone, the coverage of safe water reduced from 42% to 25% through the inclusion of the water safety parameters. The study recommends the inclusion of water quality/safety data in reported data under the UNICEF/WHO JMP.  相似文献   

9.
A national dataset on concentrations of mercury in fish, compiled mainly from state and federal monitoring programs, was used to evaluate trends in mercury (Hg) in fish from US rivers and lakes. Trends were analyzed on data aggregated by site and by state, using samples of the same fish species and tissue type, and using fish of similar lengths. Site-based trends were evaluated from 1969 to 2005, but focused on a subset of the data from 1969 to 1987. Data aggregated by state were used to evaluate trends in fish Hg concentrations from 1988 to 2005. In addition, the most recent Hg fish data (1996?C2005) were compared to wet Hg deposition data from the Mercury Deposition Network (MDN) over the same period. Downward trends in Hg concentrations in fish from data collected during 1969?C1987 exceeded upward trends by a ratio of 6 to 1. Declining Hg accumulation rates in sediment and peat cores reported by many studies during the 1970s and 1980s correspond with the period when the most downward trends in fish Hg concentrations occurred. Downward Hg trends in both sediment cores and fish were also consistent with the implementation of stricter regulatory controls of direct releases of Hg to the atmosphere and surface waters during the same period. The southeastern USA had more upward Hg trends in fish than other regions for both site and state aggregated data. Upward Hg trends in fish from the southeastern USA were associated with increases in wet deposition in the region and may be attributed to a greater influence of global atmospheric Hg emissions in the southeastern USA. No significant trends were found in 62% of the fish species from six states from 1996 to 2005. A lack of Hg trends in fish in the more recent data was consistent with the lack of trends in wet Hg deposition at MDN sites and with relatively constant global emissions during the same time period. Although few significant trends were observed in the more recent Hg concentrations in fish, it is anticipated that Hg concentrations in fish will respond to changes in atmospheric Hg deposition, however, the magnitude and timing of the response is uncertain.  相似文献   

10.
Use of lignite in power generation has led to increasing environmental problems associated not only with gaseous emissions but also with the disposal of ash residues. In particular, use of low quality coal with high ash content results in huge quantities of fly ash to be disposed of. The main problem related to fly ash disposal is the heavy metal content of the residue. In this regard, experimental results of numerous studies indicate that toxic trace metals may leach when fly ash contacts water. In this study, fly ash samples obtained from thermal power plants, namely Soma and Tunçbilek, located at the west part of Turkey, were subjected to toxicity tests such as European Committee for standardization (CEN) and toxicity characteristic leaching (TCLP) procedures of the U.S. Environmental Protection Agency (U.S. EPA). The geochemical composition of the tested ash samples from the power plant show variations depending on the coal burned in the plants. Furthermore, the CEN and TCLP extraction results showed variations such that the ash samples were classified as `toxic waste' based on TCLP result whereas they were classified as `non-toxic' wastes based on CEN results, indicating test results are pH dependent.  相似文献   

11.
From 1977–1978 to 1990, concentrations of polychlorinated biphenyls (PCBs) and most organochlorine pesticides declined in eggs of red-breasted mergansers (Mergus serrator) nesting on islands in northwestern Lake Michigan. Total PCBs decreased 60% (from 21 ppm in 1977–1978 to 8.5 ppm in 1990) and p,p-DDE decreased 66% (from 6.5 to 2.2 ppm). Dieldrin decreased only 16% (from 0.82 to 0.69 ppm). In 1990, 79.1% of incubated eggs hatched, which was not significantly different from the 83.5% that hatched in 1977–1978.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.  相似文献   

12.
The world's declining plant biodiversity depends on the efficacy of many policy tools, including Environmental Impact Assessment (EIA). While scholars have long been trying to understand how biodiversity information affects EIA decision-making, very few studies have addressed the specific challenges associated with threatened plant species. Based on content analysis of 83 EIA processes that proposed vegetation removals in the southeastern Brazilian state of Minas Gerais, this study evaluated the extent to which threatened plant species were considered in decision-making. The study found that the developers of 31 projects (37% of the 83 analyzed EIA projects) disclosed the occurrence of threatened plant species in the potentially affected areas. The detailed content analysis of their respective Environmental Impact Statement (EIS) review reports revealed that the majority of the identified impacts and respective compensation programs targeted tree habits, and under a variety of rationales. Developers' proposed compensation rates of impacted tree species varied from 1:1 to 50:1. The reviewing process reported issues related mostly to the baseline conditions. Overall, the study found that EIA, in Minas Gerais state, has been functioning mainly as a diagnostic and compensation tool for the removal of tree species. The study calls for improvements in existing legislation and the development of technical guidance and capacity-building programs for EIA stakeholders.  相似文献   

13.
Mercury (Hg) exposure was investigated through feathers of Olrog's Gull and related to health parameters in adults (hematocrit, total plasma proteins, morphometric measures, sex) and chicks (hematocrit, total plasma proteins, immunoglobulins G and M) from a colony located in estuary of Bahía Blanca, Argentina. Mercury concentrations were 5.50 ± 2.59 μg g?1 (n = 44) in live adults, 1.85 ± 0.45 μg g?1 (n = 45) in live chicks and 1.81 ± 0.41 μg g?1 (n = 41) in dead chicks. Large differences were observed between live adults and live or dead chicks and small differences between live and dead chicks. In the adults, the sex of the birds was the variable that best explained Hg concentrations. Male birds had higher concentrations than females; this suggests that the clutch provides a sink for mercury during egg laying. Hg concentrations in both adults and live chicks were associated with higher hematocrits. This could be associated with upregulated erythropoiesis to compensate for increased rate of destruction of prematurely senescent, Hg-contaminated erythrocytes. Based on our results, on the levels of Hg pollution in the past in the study area, and on the dietary specialization of Olrog's Gull, we must be vigilant about potential negative effects of Hg pollution on this population and recommend continued monitoring on this threatened species.  相似文献   

14.
Analysis of summer and winter vegetable samples during 2002–2003 for pesticidal contamination was carried out on Gas Chromatograph-Electron Capture Detector with capillary columns. The contamination levels of winter vegetables (average concentration of 4.57, 6.80 and 5.47 ppb respectively for Lindane, Endosulphan and DDT) were found to be slightly higher than the summer vegetables (average concentration of 4.47, 3.14 and 2.82 ppb respectively for Lindane, Endosulphan and DDT). The concentration of these organochlorine pesticides in summer and winter vegetables were well below the established tolerances but continuous consumption of such vegetables even with moderate contamination level can accumulate in the receptor's body and may lead to chronic effects that could be fatal.  相似文献   

15.
Sediment samples were collected in two Polish ports of international significance--the Port of Gdańsk and the Port of Gdynia (Gulf of Gdańsk, Baltic Sea)--in order to assess their butyltin and phenyltin contamination; this was done in 2008, just after the total ban on using harmful organotins in antifouling paints on ships came into force. Altogether, 21 sampling stations were chosen to present a diversity of port sites: from port canals and shipyards to anchorages and dumping sites. The organic carbon content and grain size of all the sediment samples were determined, and some environmental parameters (oxygen content, salinity) were measured as well. Total concentrations of butyltin compounds in sediment samples were very different and ranged between 1 and 18,520 ng Sn g(-1) d.w. Phenyltin contents were distinctly lower and ranged from below the limit of detection (most samples) to 660 ng Sn g(-1) d.w. The highest concentrations of organotins were found in the shipyards, the maximum total organotin content (19,180 ng Sn g(-1) d.w.) being found in the Gdańsk Ship Repair Yard 'Remontowa'. Butyltin degradation indices indicate a recent tributyltin input into the port sediments. The results obtained from this work prove that the international ban on using organotins may not be enough to protect the marine environment. It is necessary to monitor organotin contamination in ports and establish concentration limits of these compounds for the disposal of dredged material at sea.  相似文献   

16.
This study was designed to evaluate the degree of environmental contamination and possible exposure of pregnant women to toxic elements in seven selected areas of S?o Paulo State, Brazil. The overall median concentration of Mo in maternal blood was 0.53 μg L?1, highly significant differences found between sites (p < 0.0001). Cd was found to be low overall - 0.09 μg L?1 (0.01-0.58 μg L?1) - with mothers from the Coastal and Rural 1 sites having the highest levels (p < 0.016).Median Hg concentration was 0.60 μg L?1 (0.06 μg L?1-4.35 μg L?1); median Pb level was 16.2 μg L?1 (3.5-57.7 μg L?1) and no differences between sites were observed for both metals. Median Mn level was 16.7 μg L?1 (7.0-39.7 μg L?1), being highest in Urban 2 site (p < 0.016). Concentrations of maternal Co were found to range between 0.06 μg L?1 and 1.1 μg L?1 (median 0.25 μg L?1) and As level was 0.60 μg L?1 (0.10-3.8 μg L?1) overall, with no statistical significance between sites for Co and As. Median Se concentrations were found to be 64 μg L?1 (36-233 μg L?1), with the highest median levels found in Urban 3 site; site differences were statistically significant (p < 0.0001). Correlation for each element (between paired maternal and cord blood) was measured only in Rural site 1; significant correlation was shown for Hg, Pb, Mn and Co (p < 0.05). These findings may be interpreted as indicating low environmental contamination in S?o Paulo State, Brazil. These findings could also indicate that pregnant women have little or no contact with pollutants, possibly due to awareness campaigns carried out by public health practitioners.  相似文献   

17.
Concentration of the some heavy metals (Co, Cu, Fe, Ni, Pb and Zn) Mediterranean mussel Mytilus galloprovincialis from Yalova (Marmara Sea) were investigated seasonally. The mean concentrations of Co, Cu, Fe, Ni, Pb and Zn in the soft tissues were 4.08 ± 0.67, 5.54 ± 0.59, 156.72 ± 20.18, 3.71 ± 1.14, 2.92 ± 0.51 and 106.23 ± 5.66 mg kg(?-1) dry weights, respectively. There were no significant differences between the metal concentrations among the seasons (P > 0.05). The mean Pb and Zn concentrations were higher than the acceptable limit proposed by International Turkish standards.  相似文献   

18.
The mass concentrations and major chemical components of PM(2.5) in Jinan, Shandong Province, China from Dec. 2004 to Oct. 2008 were analyzed using backward trajectory cluster analysis in conjunction with the potential source contribution function (PSCF) model. The aim of this work was to study the inter-annual variations of mass concentrations and major chemical components of PM(2.5), evaluate the air mass flow patterns and identify the potential local and regional source areas that contributed to secondary sulfate and nitrate in PM(2.5) in Jinan. The annual mean concentrations of PM(2.5), sulfate and nitrate in 2004-2008 were almost the highest in the world. The most significant air parcels contributing to the highest mean concentrations of mass and secondary ions in PM(2.5) originated from the industrialized areas of Shandong Province. Clusters with a lower ratio of NO(3)(-)/SO(4)(2-) in PM(2.5) originated from the Yellow Sea, while a higher ratio was observed in the clusters passing through Beijing and Tianjin. PSCF modeling indicated that the provinces of Shandong, Henan, Jiangsu, Anhui and the Yellow Sea were the major potential source regions for sulfate, in agreement with the cluster analysis results. Regional and long-range transport of NH(4)NO(3) played an important role in the nitrate concentration of Jinan. By comparing the distributions of secondary sulfate and nitrate over three years, enhanced emission control management before and during the 29(th) Olympic Games led to a discernible decrease in source contributions from Beijing and its environs in 2007-2008.  相似文献   

19.
The objectives of this study were to use both parametric and probabilistic approaches to analyze water column concentrations of both salinity (24,845 measurements) and boron (13,028 measurements) from numerous investigations conducted in the San Joaquin River watershed from 1985 to 2002 to assess spatial and temporal trends and determine the probability of exceeding regulatory targets during both the irrigation and non-irrigation season. Salinity and boron concentrations from 26 mainstem and tributary sites were highly correlated based on this 17 yr data set. Generally, salinity and boron concentrations were higher in winter/spring and lower in summer/fall; higher concentrations of both constituents were reported in tributary sites when compared with the mainstem San Joaquin River. Approximately half the sites showed showed a negative correlation between flow and both constituents. Concentrations of both salinity and boron were somewhat variable with flow conditions for the other sites. Both linear and curvilinear trends were inconsistent over time. The salinity 90th centiles for the 26 sites ranged from 143 to 7,559 micros cm(-1) with the highest 90th centiles in tributary sites. Probabilistic analysis of salinity 90th centiles by year for five sites with extensive data showed a significant decrease over time at two sites and no significant trend for the other three sites. The probability of exceeding the salinity targets during either the irrigation (700 microm cm(-1)) or non-irrigation (1,000 micros cm(-1)) season was greater than 19% for all but three sites. The boron 90th centiles for the 26 sites ranged from 0.41 to 13.6 mg L(-1) with the highest 90th centiles from tributary sites. Probabilistic analysis of the boron 90th centile values by year for the five sites with the most extensive data showed a significant decrease over time at two sites and no significant trend for the other three sites. The probability of exceeding the boron target during the irrigation season (0.80 mg L(-1)) and non-irrigation (1.0 mg L(-1)) season was greater that 18% for all but three sites. Results from this analysis have important regulatory implications as targets for both salinity and boron are frequently exceeded at various sites in the San Joaquin River watershed.  相似文献   

20.
The spill at `Los Frailes caused a large input of metals intothe riverine, estuarine and coastal ecosystems. Metal behaviourin natural waters can be studied both by performing fieldmeasurements, and by undertaking laboratory simulationexperiments. Here is described the behaviour of the heavymetals Zn, Cd, Pb and Cu in the Guadalquivir estuary usingincubation experiments and the results compared to thoseobtained during field assessments. If the toxic waste water hadbeen discharged untreated into the environment, it could haveraised the heavy metal concentrations in the estuary water tohigh values, such as 20.65 M for Zn and 40 × 10-3 M for Cd. These values are several times higher than thoseobtained in samples collected in the area during the monitoringof the early impact. The metals present a non-conservative behaviour, with a high loss to waters of low salinity values.  相似文献   

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