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341.
渤海辽东湾表层沉积物中金属元素分布特征   总被引:14,自引:4,他引:14  
利用X射线荧光光谱(XRF)、等离子质谱仪(ICP-MS)和原子荧光光度计(AFS)分别测定了辽东湾表层沉积物中的金属元素含量,探讨了它们的分布特征、来源及污染程度.结果表明,沉积物中Cu、Zn、Pb、Cd、Ni、Cr、Co、Hg、As和Ag等元素含量在空间分布上存在明显梯度,其空间分布模式(4种)受到沉积物细粒组分、有机质含量及与河口间距离等因素的制约.通过与沉积物质量标准及其他海区的比较,评价了研究区沉积物中几种重要金属元素(Cu、Zn、Pb、Cd、Cr、Ni、Ag、Hg和As)的污染情况.富集系数显示, Fe、Ti、Mn、P、Cu、Zn、Ni、Cr、Co、Sc和V为无富集;As为轻度富集;Pb、Cd、Ag和Hg为中度富集. Fe、Ti、Cu、Zn、Cr、Ni、Co、Mn、P、V和Sc主要来源于陆地岩石和土壤风化产物;Pb和As既有岩石和土壤风化产物等自然源的贡献,又受到了人为活动的影响;Hg、Cd和Ag主要来自人为源;Ba和Sr主要与海洋生物活动有关.依据沉积物质量综合评价,将辽东湾沉积物划分为4类.  相似文献   
342.
能源规划环境影响评价内容框架研究与探讨   总被引:1,自引:2,他引:1  
从环境与发展综合决策的角度,以浙江省2010年电力发展规划及2020年展望的能源类规划环评为案例,对能源类规划环评的内容框架作初步研究。  相似文献   
343.
以水质一维流方程为基础,建立了水源地区非点源污染物入河量计算的反演模型;计算了浙江省湖州市老虎潭水库水源地区各条支流的非点源污染物入河量;并通过对实测水文水质参数的统计,采用Monte Carlo模拟方法,分析了模型各输入参数的敏感性.由于该模型所有敏感参数都可以实测获得,避免了关键参数取值的人为主观因素的影响,保证了非点源污染过程定量分析的客观性;该模型在计算非点源污染物入河量时不受时间的限制,可以根据研究区域的水文水质监测频率计算任意时段内的非点源污染物入河量.结果表明,该水源区所有溪流中的氮、磷污染物负荷量都与溪流流量呈极显著正相关(r0.90,p0.01),因此,丰水期是非点源污染物入河的集中期;对输入参数的敏感性分析显示,对模型输出结果影响最大的是溪流的流量,其次是段末浓度和背景浓度,综合降解系数和流速的影响较小.  相似文献   
344.
    
Long-term changes of fish biotic integrity in the Sanmenxia Wetland,North China,since the 1950 s were assessed using the fish index of biological integrity(FIBI). The water and sediment quality was evaluated by the water quality index(WQI) and sediment pollution index(SPI). The results showed that FIBI continuously decreased from 46 to 20 during the past 5 decades,which indicated that the fish community state shifted from fair to very poor conditions,and damming by itself did not affect the fish biotic integrity. At the same time,WQI fell from 83 to 44.1,and SPI increased from 0.99 to 2.14 since the 1960 s,resulting from fast regional socio-economic development and insufficient wastewater treatment. Correlation analysis suggested that water quality significantly affected biotic integrity(r = 0.867,p 〈 0.05) through direct effects on the fish community. As a representative example of many wetlands in North China,our study clearly demonstrated that the biological integrity was degraded,induced both by water quality deterioration and sediment pollution,further driven by the contradiction between rapid development of regional economy and lagging development of sewage treatment facilities,which were thought to be the main factor responsible for the degradation of biological integrity.  相似文献   
345.
The implementation of sustainable development requires several support instruments. One of the major instruments in the Rio Declaration to support this process has been environmental assessment that has been given considerable emphasis as to its potential ability to help achieve more sustainable forms of development. Regional environmental assessment (REA) has shown to be effective in supporting local sustainable development process. Selected environmental assessment methods have been␣used to improve the REA exercise and provide reliable data for decision-making not only to correct environmental problems due to past unsustainable social-economic developments but also help local governments to implement Agenda 21 (AG21) plans and projects.  相似文献   
346.
Understanding the earth system requires that the two-way linkages between regions and the global system be well understood and predictable. Most studies of global change are undertaken thematically across limited disciplinary boundaries; few are attempted holistically across many disciplines within regions. The regional approach offers many advantages. Here a variety of linkages associated with the regions of Southern Africa, South Asia, East Asia and Southeast Asia are presented to illustrate the power of a regional approach to earth system science. Major findings include the extent to which long-range transport of aerosols and nutrients affect terrestrial and marine ecosystem functioning in and around southern Africa. Aerosol transport, and the development of a regional haze layer, over South Asia are shown to alter significantly the radiative forcing of change in the atmosphere over the region. Changes in land cover and use over East Asia over along period of time are shown to have affected the strength of the monsoon circulation significantly. Finally, rampant economic development and globalization in Southeast Asia are demonstrated to have been a significant driver of regional change. Electronic Publication  相似文献   
347.
上海青紫泥土壤氮素淋溶及其对水环境影响研究   总被引:24,自引:2,他引:24  
农田氮素淋失受多方面因素的影响,其淋失研究有多种方法,利用渗漏池,在上海青浦农田水利试验站进行青紫泥土壤氮素的淋溶模拟试验,以探讨不同水肥管理方式下的淹水稻田中,氮素的迁移,转化机制及其对水环境的影响,研究结果表明:淹水稻田中氮素淋失的基本形态为硝态氮(NO3^-,N),在下渗水流的驱动下,NH4+-N也能渗漏到一定的深度,对地下水环境形成威胁,但不如NO3-N显著;不同处理的剖面中NO3--N和NH4+-N浓度均表现出随深度增加逐渐降低的趋势,每次施肥后,不同处理剖面中的NO3_N浓度均表现为短期内迅速上升,后期逐渐下降的趋势,其中NH4+-N浓度与NO3--N的消长规律相似,但表现出峰值超前且变幅远大于NO3--N浓度的特征;氮素的淋失主要发生在当年的6-8月份之间,此期与降雨高频期的重叠加剧了对水环境的污染,采用节水节肥的管理模式,不仅能保护产量,还能减少灌溉量,大大降低施用氮肥对地下水污染的威胁。  相似文献   
348.
水源地是城市水资源可持续供给的重要空间载体。伴随城市化的快建发展,城市水资源供求压力日起紧张,城市水源地在保障城市水资源可持续供给方面的作用日益突出。本文从城市化过程中的水资源需求变化出发,揭示水源地在城市可持续发展中的战略地位,评析我国水桓交易的理论研究进展,在此基础上提出我国城市水源地建设保护过程中水权交易的走势判断。  相似文献   
349.
We downscale the results of a global tourism simulation model at a national resolution to a regional resolution. We use this to investigate the impact of climate change on the regions of Germany, Ireland and the UK. Because of climate change, tourists from all three countries would spend more holidays in the home country. In all three countries, climate change would first reduce the number of international arrivals—as Western European international tourist demand falls—but later increase numbers—as tourism demand from increasingly rich tropical countries grows. In Ireland and the UK, the regional pattern of demand shifts is similar to the international one: tourism shifts north. In Germany, the opposite pattern is observed as the continental interior warms faster than the coast: tourism shifts south.
Jacqueline M. HamiltonEmail:
  相似文献   
350.
In this paper, we explore how scenarios of future water withdrawals in a river basin are influenced by scale-dependent quantifications of the driving forces for two global-scale storylines. Either global-scale information or region-specific information is used to do the quantifications. In addition, we analyze the impact of including or not some restricted regional-scale information in the employed water use model. To develop scenarios of water withdrawals in the German part of the Elbe River basin, we applied the modules for domestic, thermoelectric power and manufacturing water use of the global water model WaterGAP, using scale-dependent driving forces scenarios and other scale-dependent model input. In the global-scale quantitative interpretations of the storylines of the IPCC SRES scenarios A1 and B2, all major driving forces of water withdrawals in the basin—population, thermoelectric power production and industrial gross domestic product—show vigorous increases between 2000 and 2025, while from the regional perspective, smaller increases but mostly decreases appear to be plausible. These discrepancies are partly due to the fact that for the global-scale interpretations only the historic developments until 1990 were taken into account, and not until 2000 as in the regional case. The resulting scenarios of sectoral water withdrawals in 2025 differ strongly between the two scale-dependent interpretations of the storylines, with the global one leading to much higher absolute water withdrawals and much lower withdrawal decreases between 2000 and 2025. Therefore, for regional assessments of water withdrawals, we recommend to embed the scenario analysis in global-scale storylines by performing regional-scale quantifications of the global qualitative driving forces scenarios, based on a limited amount of region-specific information.  相似文献   
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