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浅析环境信息公开的作用 总被引:1,自引:0,他引:1
环境信息公开能提高环境保护参与者的环境意识,改变他们的环境行为和行动,解决"市场失灵"、"政治失灵"的问题,教育环境保护各利益相关者,推进决策过程中的民主进程。要提高环境信息的作用,应公开公众所面临的环境风险,公开的环境信息必须可靠,有关的环境信息必须对公众有用且方便获得,政府机构应关注公众对环境信息的反馈。 相似文献
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微塑料污染是当前环境科学关注的研究热点.为探究国家一级水源保护区丹江口水库中微塑料的赋存状况,以水库及其入库支流表层水体为对象,于2019年丰水期进行采样调查分析,研究该区域的微塑料丰度、形状和类型,并结合丹江口水库的水文水动力条件揭示其微塑料空间分布特征.结果表明,丹江口水库水体中微塑料颜色各异,主要形状有颗粒、碎片、薄膜以及纤维类这4类,其中碎片类占比为84.2%,棕色和透明微塑料最为常见,而不同形状微塑料丰度空间分布差异明显;丰水期,水库库区微塑料平均丰度7248 n·m-3,丹库的微塑料含量显著高于汉库;库区与支流中微塑料粒径大小主要在75~4703 μm之间,微塑料丰度随粒径的增加而下降,其中73.4%的微塑料粒径在500 μm以下;就微塑料材质而言,尼龙在丹江口水库中最普遍,数量比例为36.4%;其次是聚乙烯(PE)和聚丙烯(PP)等. 相似文献
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为了研究使用随机化Pushover方法进行RC框架结构整体抗震可靠度计算过程中相关参数的适应性,使用Matlab调用SAP2000编制出基于随机化Pushover的结构整体抗震可靠度程序,以一榀11层RC框架结构为例,通过该程序统计出不同参数下结构最大层间位移角的分布情况及整体失效概率,并以大样本实际地震波进行时程分析所统计出的相应结果为基准进行对比。结果表明,在常规参数设置下随机化Pushover方法统计出的最大层间位移角分布情况和结构整体失效概率与大样本时程分析结果有较大差异,然后提出了一种修正方式,有效地减小了两者的差异,并以某算例验证了该修正方式的适用性。 相似文献
629.
The littoral zone in the Three Gorges Reservoir, China: challenges and opportunities 总被引:3,自引:0,他引:3
Xing-zhong Yuan Yue-wei Zhang Hong Liu Sen Xiong Bo Li Wei Deng 《Environmental science and pollution research international》2013,20(10):7092-7102
For flood control purpose, the water level of the Three Gorges Reservoir (TGR) varies significantly. The annual reservoir surface elevation amplitude is about 30 m behind the dam. Filling of the reservoir has created about 349 km2 of newly flooded riparian zone. The average flooding period lasts for more than 6 months, from mid-October to late April. The dam and its associated reservoir provide flood control, power generation, and navigation, but there are also many environmental challenges. The littoral zone is the important part of the TGR, once its eco-health and stability are damaged,which will directly endanger the ecological safety of the whole reservoir area and even the Yangtze River Basin. So, understanding the great ecological opportunities which are hidden in littoral zone of TGR (LZTGR) and putting forward approaches to solve the environmental problems are very important. LZTGR involves a wide field of problems, such as the landslides, potential water pollution, soil erosion, biodiversity loss, land cover changes, and other issues. The Three Gorges dam (TGD) is a major trigger of environmental change in the Yangtze River. The landslides, water quality, soil erosion, loss of biodiversity, dam operation, and challenge for land use are closely interrelated across spatial and temporal scales. Therefore, the ecological and environmental impacts caused by TGD are necessarily complex and uncertain. LZTGR is not only a great environmental challenge but also an ecological opportunity for us. In fact, LZTGR is an important structural unit of TGR ecosystem and has special ecosystem services function. Vegetation growing in LZTGR is therefore a valuable resource due to accumulation of carbon and nutrients. Everyone thinks that the ecological approach to the problem is needed. If properly designed, dike–pond systems, littoral woods systems, and re-created waterfowl habitats will have the capacity to capture nutrients from uplands and obstruct soil erosion. Ecological engineering approaches can therefore reduce environmental impacts of LZTGR and optimize ecological services. In view of the current situation and existing ecological problems of LZTGR, according to function demands such as environmental purification, biodiversity conservation, and vegetation carbon sink enhancement, we should explore the eco-friendly utilization mode of resources in LZTGR. Ecological engineering approaches might minimize the impacts or optimize the ecological services. Natural regeneration and ecological restoration in LZTGR are valuable for soil erosion decrease, pollutant purification, biodiversity conservation, carbon sink increase, and ecosystem health maintenance in TGR. 相似文献
630.
Feng XH Zhai LM Tan WF Liu F He JZ 《Environmental pollution (Barking, Essex : 1987)》2007,147(2):366-373
Several Mn oxide minerals commonly occurring in soils were synthesized by modified or optimized methods. The morphologies, structures, compositions and surface properties of the synthesized Mn oxide minerals were characterized. Adsorption and redox reactions of heavy metals on these minerals in relation to the mineral structures and surface properties were also investigated. The synthesized birnessite, todorokite, cryptomelane, and hausmannite were single-phased minerals and had the typical morphologies from analyses of XRD and TEM/ED. The PZCs of the synthesized birnessite, todorokite and cryptomelane were 1.75, 3.50 and 2.10, respectively. The magnitude order of their surface variable negative charge was: birnessite> or =cryptomelane>todorokite. The hausmannite had a much higher PZC than others with the least surface variable negative charge. Birnessite exhibited the largest adsorption capacity on heavy metals Pb(2+), Cu(2+), Co(2+), Cd(2+) and Zn(2+), while hausmannite the smallest one. Birnessite, cryptomelane and todorokite showed the greatest adsorption capacity on Pb(2+) among the tested heavy metals. Hydration tendency (pK(1)) of the heavy metals and the surface variable charge of the Mn minerals had significant impacts on the adsorption. The ability in Cr(III) oxidation and concomitant release of Mn(2+) varied greatly depending on the structure, composition, surface properties and crystallinity of the minerals. The maximum amounts of Cr(III) oxidized by the Mn oxide minerals in order were (mmol/kg): birnessite (1330.0)>cryptomelane (422.6)>todorokite (59.7)>hausmannite (36.6). 相似文献