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861.
玉苏甫·阿布都拉 热依汗古丽 买买提阿布都拉 米吉提·依明 Yusup·ABDULLA Reyhanguli Maimaitiabudula Mijit·IMIN 《沙漠与绿洲气象(新疆气象)》2006,29(1):24-25,29
对1963~2004年和田市各级别大气能见度进行统计分析,揭示了大气能见度的年际变化和季节变化特征。近20a来和田市大气环境质量趋于好转,造成能见度恶化的重要原因是大气中悬浮颗粒的增多,因此大气能见度是评价大气环境质量的重要指标。 相似文献
862.
Rajasekhar Balasubramanian Siao Wee See 《中国地球化学学报》2006,25(B08):221-222
Biomass burning, the burning of living and dead vegetation for land-clearing and land-use change, has been in practice in many tropical countries such as Brazil, Indonesia, Nigeria, and Mexico. Intense forest fires can also ignite subsurface organic soil components (e.g. peat), which can continue to smolder long after the original surface fires are put out. Combustion of vegetation and peat has only recently been recognized as a major source of atmospheric pollution. The immediate effect of burning is the production and release of gases and particles into the atmosphere, in quantities that in some cases can be significant not only locally and regionally but also on a global scale. Vegetation fire emissions account for roughly half of the atmospheric constituents of hydrocarbon, carbon monoxide, nitrogen oxides, and precursors of tropospheric ozone and may be the second largest source of anthropogenic aerosols after the production of sulfates from SO2. As a result, there has been considerable interest in studying the contribution of forest fires to the production of air pollutants. In recent years, Southeast Asian countries have been affected repeatedly by episodes of smoke haze from forest fires in Indonesia. During 1997-1998, the region was again shrouded in a haze worsened by prolonged drought linked to the E1 Nino weather phenomenon. Satellite pictures confirmed that air pollutants, originating from fires covering an estimated 800000 hectares of southern Kalimantan, Sumatra, and Java, have been transported by southwesterly monsoon winds across neighbouring Malaysia and Singapore to as far as Thailand and the Philippines. The impact of these extensive fires on the health of the residents and ecology in the affected areas was substantial, costly, and possibly long lasting. Most of the research on the environmental aspects of biomass burning has been directed towards the tropics in Africa and America, specifically to the tropical rain forests of Brazil and to the savannas of Africa and South America. 相似文献
863.
864.
Soil and water pollution derived from anthropogenic activities in the Porsuk River Basin, Turkey 总被引:1,自引:0,他引:1
This study aims to investigate the degree of the influence of contaminant sources on both the surface (Porsuk River) and groundwater
in the Eskisehir plain, (Turkey) and to determine the changes in groundwater quality after the sewage system was started in
1998. For this purpose surface and groundwater samples were collected from various locations in the Eskisehir plain between
May and October, 2001. The Porsuk River is already polluted in the upstream wastewater and by industries such as Nitrogen
Fertilizer Factory, Sugar-beet Factory, and Magnesite Factory located around the city of Kutahya. This high-contaminated water
forms an eutrophic environment which generates high phosphorus and nitrogen in downstream flow. Agricultural and industrial
activities in the Eskisehir plain are an additional source of the pollution of the Porsuk River. The study revealed that some
trace elements, Pb, Cr, Mn, Fe, and Cd, are present in high concentrations both in the surface and groundwater besides extremely
high quantities of phosphorus, nitrogen and sulfide compounds. In addition, analyses of samples also indicated that there
are no considerable contaminations in terms of local pesticides. High concentration of Cd, N and S are found in the groundwater.
On the basis of a detailed analysis of the groundwater in the Eskisehir plain, it is concluded that groundwater is not suitable
for drinking according to Turkish standards, European Union Standards (EU) and World Health Organization (WHO).
An erratum to this article can be found at 相似文献
865.
Eiliv Steinnes 《中国地球化学学报》2006,25(B08):5-5
A large part of the Northem Hemisphere is covered by podzols and similar soil types, which have a surface layer characterized by high organic matter content. This layer is extremely important because it is the main source of plant nutrients. The elemental composition of the surface soil however is often strongly different from that of the underlying mineral soil, which may be due to a combination of natural processes and anthropogenic influence. Research in Norway over the last 30 years has contr/buted to the understanding of the relative importance of different factors in modifying the chemistry of the surface soil. The country is relatively pristine, but is substantially influenced in the south by atmospheric supply of pollutants from other parts of Europe. Vegetation is relatively uniform over large parts of the country, but climatic variations related to oceanic influence are considerable. 相似文献
866.
Shehong LI Baoshan ZHENG Jianming ZHU Xiaoying YU 《中国地球化学学报》2006,25(B08):43-44
Uranium and Th are important radioactive elements. Most studies were focused on their environmental impact from uranium deposits and mining sites. But other sorts of mines such as rare metals mines are associated highly with uranium and thorium, too. In China, the Irtysh River is the only river that runs into the Arctic Ocean. The famous Koktokay rare metal pegmatite deposit is located in the headwater region of this river and has been exploited for several decades. The waste ore piled along the riverside as long as several kilometers. The wastewater flom the concentrating plant is discharged into the river directly. In addition, uranium and thorium can be leached from the waste ore into the river in the weathering process. So it is necessary to study the uranium and thorium distribution in the branch and trunk streams of the Irtysh River and the wastewater from the mining site impact on it. In this study, the contents of uranium and thorium in water samples from the Irtysh River and rare metal mine wastewater have been detected directly with ICP-MS. Uranium and thorium distribution and geochemical behaviors in the Irtysh River basin have been studied. The environmental uranium and thorium pollution status in the Irtysh River and wastewater from a rare metal mine impact on it have also been evaluated. The study shows that uranium and thorium contents in wastewater from a rare metal mine are as high as 78.311 μg/L and 0.627 μg/L, respectively, so we should also pay attention to the radioactive pollution from the rare metal mine. The average contents of U and Th in the branch streams of the Irtysh River are 0.572 μg/L and 0.015 μg/L, respectively. At the mean time, in the trunk of the Irtysh River, average thorium content is 0.019 μg/L while U is up to 2.234 μg/L, much higher than the average content (0.0309 μg/L) of the world rivers. From upstream to downstream in the trunk of the Irtysh River, thorium content declines gradually due to dilution by other branches and deposition itself. 相似文献
867.
Hamid Reza Rahmani 《中国地球化学学报》2006,25(B08):110-110
Even though, application of industrial effluent water may alleviate the irrigation water shortage in dry regions such as Iran, but uncontrolled discharge into environment and agricultural land may cause unirreversible harmful damage to environments. Therefore, application of industrial effluent water should consider the environmental consequences such as soil, ground water and food contamination. In this study the effect application of Zob-Ahan effluent water for irrigation water and seepage from evaporation ponds on the chemical composition of surrounding well-water were seasonally investigated from April to March in 2003. The water from the selected well was sampled and analyzed for pH, EC, nitrate, hardness, TSS, TDS, and cations including Na^+, Ca^2+, Mg^2+, anions including SO4^2-, CO3^2-, HCO3^-, Cl^-, and heavy metals including Pb, Cd, Cu, Fe, Cr, Mn, Co, and Zn . The results were compared with standard levels for ground water resources, irrigation water, and direct human consumption. The result shows that the ground water in the vicinity of effluent water application fields and evaporation ponds is contaminated and the concentrations of NO3, Cl and Fe are higher than standard permissible levels for ground water resources. For irrigation or discharge into absorption well the heavy metal concentrations of Cu, Cr, Co, and Fe are limiting. 相似文献
868.
869.
Remote Sensing Methods to Investigate Boundary-layer Structures relevant to Air Pollution in Cities 总被引:2,自引:0,他引:2
Simultaneous surface-based remote sensing with optical (Ceilometer) and acoustic (Sodar) methods allows the diurnal variation of the structure of the atmospheric boundary layer to be deduced with high temporal resolution. Primarily the convective boundary layer, the nocturnal stable surface layer, and the residual layer can be identified from the measured vertical profiles of aerosol concentration and thermal fluctuations. The ability of the two remote sensing techniques is shown in different examples from two different locations and two seasons. The impact on urban air quality assessment is addressed. 相似文献
870.
Many organisms have been used as bioindicators of atmospheric contamination, with moss and lichen species being the most common. However, studies using epiphytic vascular species of Tillandsia have shown a good correlation between the presence of pollutants and the bioindicator's response. Therefore, the aim of our investigation was to calibrate and compare the response of four Tillandsia species of Argentina to ascertain whether they could be used as atmospheric contamination biomonitors. For this, we analysed the correlation between the levels of heavy metals in total atmospheric deposition samples and: a) their rate of enrichment; b) the physiological response of the plant samples.
Tillandsia samples collected from a non contaminated area in the province of Córdoba were transplanted to four areas in the capital city with different sources of pollution (industrial or traffic emissions). They were exposed for a period of 3 to 6 months after which the concentrations of Pb, Ni, Fe, Zn, Cu and S as well as the physiological parameters of foliar damage were determined. Simultaneously samples of total atmospheric deposition were also taken.The highest level of metal enrichment was found in T. capillaris followed by T. tricholepis, T. permutata and T. retorta. Also, the use of a foliar damage index proved to be effective and could be a useful tool to evaluate different levels of atmospheric quality in these species. The rate of heavy metal deposition was higher in the industrial area for all metals except for Zn whose values were higher in areas with high levels of traffic. 相似文献