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171.
通过对个旧市 2 0 0 0年和 2 0 10年大气SO2 排放量的预测及对环境空气质量的影响预测 ,提出SO2 污染防治措施以及SO2 削减计划 ,从而确定出既能满足个旧市环境空气质量功能分区目标 ,又与国家对酸雨控制区的规划目标一致的个旧市 2 0 0 0年至 2 0 10年大气SO2 总量控制目标 ,以确保酸雨和SO2 污染不断恶化的趋势得到遏制 相似文献
172.
Globally, ecosystem-based marine spatial planning has become a useful instrument to coordinate the planning of different authorities. This, for balancing different requirements when managing marine areas and space. In the planning process, ecology is setting limits to which human activities are acceptable to the society. The use of the marine environment can be planned similarly as the land environment. We argue that there are several aspects which must be taken into consideration. Marine activities have traditionally been planned and managed in a sectoral way. Today, it has become obvious that a more holistic, multi-sectoral and coordinated approach is needed in future successful marine planning and management. The increased awareness of the importance of the oceans and seas challenges the traditional sector division and geographical limits in marine policy and calls for better coordinated and coherent marine policies. 相似文献
173.
为研究辽东湾PAHs(多环芳烃)在海水-沉积物之间的扩散行为,于2014年5月对辽东湾14个采样点海水和沉积物中的16种PAHs进行了调查研究,并采用逸度方法、变异系数、响应系数等统计和计算方法对研究结果进行分析.结果表明:辽东湾海水中ρ(∑PAHs)和沉积物中w(PAHs)的平均变异系数分别为0.25和0.39,属于中等变异,高分子量PAHs的变异系数高于低分子量PAHs;利用ff(逸度分数)评估PAHs在海水-沉积物间的扩散行为,Nap(萘)、Acp(苊)和Fl(芴)表现出从沉积物向海水释放,沉积物是二次释放源;Ace(二氢苊)、Phe(菲)、An(蒽)、Flu(荧蒽)、Pyr(芘)、BaA(苯并[a]蒽)、Chr(?)在海水-沉积物之间接近平衡状态,5环和6环PAHs则表现出从海水向沉积物沉降富集,沉积物是汇;有机碳和碳黑是影响PAHs在沉积物和海水之间扩散的重要参数.研究显示,7种潜在致癌PAHs[BaA、Chr、BbF(苯并[b]荧蒽)、BkF(苯并[k]荧蒽)、BaP(苯并[a]芘)、InP(茚并[1,2,3-cd]芘)和DbA(二苯并[a,h]蒽)]海水-沉积物之间的扩散行为可能受到陆源排污和海上石油开发活动的影响. 相似文献
174.
长江口沉积物重金属赋存形态及风险特征 总被引:7,自引:1,他引:6
基于长江口沉积物8种重金属(As、Cd、Cr、Cu、Hg、Ni、Pb、Zn)总量与形态在丰、平、枯水期以及14个典型点位的分布特征,通过平衡分配法建立了长江口沉积物质量基准(SQGs),并以此评价长江口沉积物重金属生态风险,揭示重金属生态风险与其形态特征间的相关关系.结果表明,除Cd之外,长江口沉积物重金属以残渣态为主导形态,尤其是As、Cr、Hg,其残渣态含量均为90%以上.长江口As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的沉积物质量基准分别为43.29、0.672、79.65、19.08、0.569、339.09、30.87、411.36μg·g~(-1).Cu的生态风险程度最高,对水生生物具有较大的毒性影响,应当引起重视.河口上游受到长江径流影响大,在丰水期风险较高,在平水期和枯水期则风险偏低;而下游受上海等城市排污影响较大,风险较高(尤其在平水期和枯水期).8种重金属的生态风险与赋存形态之间表现出3种不同的相关关系. 相似文献
175.
借鉴西方标准曾对我国保护地制度的建立起到了重要作用。然而,当前国际标准对我国已建立起来的保护地体系已经显现出不适用,因此有必要对其进行反思。回溯我国及世界保护地制度的建立过程及其关联,由于我国在国际保护地标准制定过程中参与度过低,导致我国保护地的特性与发展阶段需求在国际标准中体现不足。我国保护地具有的文化景观属性,即传统的“天人合一”的环境观与西方人和自然对立的思想截然不同。我国保护地面临着保护与发展双重挑战,直接将基于特定人口状况和发展阶段的保护地所制定的标准用于其他状况下的保护地,其合理性存在着问题。应更加批判地看待西方标准,积极探讨可持续和平发展的中国路径。 相似文献
176.
A Bayesian-updating approach is presented to the estimation of total uncertainty-based Margin of Safety (MOS) for Total Maximum Daily Load (TMDL) calculations. Probability distributions are presented to construct the likelihood function, the prior probability distribution, and the posterior (total uncertainty) probability distribution. The Bayesian-updating approach is demonstrated through a case study for the Lower Amite River, Louisiana. The posterior probability distribution-based on the Bayesian approach updates the standard deviation of summer dissolved oxygen in the Amite River from 1.88 mg/L to 2.10 mg/L when the total uncertainty is considered. Results from the Bayesian-updating approach are compared with two conventional methods. The dissolved oxygen reserve based on a conventional margin of safety of 20% is estimated to be 45,682.26 kg/Day. The second conventional method, where we consider the standard deviation of 1.88 mg/L, produces a dissolved oxygen reserve of 40,516.09 kg/Day. The Bayesian approach yields the dissolved oxygen reserve of 38,614.43 kg/Day with the first level (μ-σ) of MOS, producing a deficit of 5606.65 kg/Day in dissolved oxygen. The dissolved oxygen reserve deficit increases to 23,895.13 kg/Day when the second level (μ-2σ) of MOS is used, which escalated to 42,383.52 kg/Day when the highest level (μ-3σ) of MOS is used. While the total uncertainty-based Bayesian approach is demonstrated for a TMDL development on the Amite River, the overall approach could be applied in any river system with similar available data. 相似文献
177.
178.
This paper applies an ecosystem approach to analyse the livelihood of fishers dependent on the Old Brahmaputra River in Mymensingh, Bangladesh. Results suggest that the livelihood of fishers is increasingly threatened because of the fragile river ecosystem and poor livelihood assets. Most fishers face a wide range of vulnerability including shocks, trends and seasonality. This is because the ecosystem of the resource base on which their livelihood depends (i.e. the Old Brahmaputra River) has been degraded severely resulting in a significant decline in fish catch due to a combination of factors, such as over-fishing, use of destructive fishing gears, water pollution, siltation, rapid urbanisation and environmental degradation. We propose an adoption of the socio-ecological system with active community participation in the management of the resource base and collaboration amongst key stakeholders to produce positive livelihood outcomes for the fishers. 相似文献
179.
180.
Within pinnipeds, phocids and otariids show differing maternal care strategies. Phocids rear young out of body stores in a yearly cycle with a single stay ashore when the mother fasts while lactating, whereas otariids provision their young by repeated foraging trips to sea alternating with brief stays ashore where they suckle their young. In a previous optimality model, these differences have been interpreted as adaptations based on differing energy requirements of large (phocid) and smaller (otariid) species, and the time budget of the large elephant and the much smaller Antarctic fur seal were correctly predicted. Our refined model—extended to pinniped species of all sizes—predicts lactation strategies to shift from attendance cycles to 1-year cycles with increasing body mass and provides an explanation for the finding that phocid pups are weaned at lower relative mass than otariid pups. However, other predictions do not correspond to empirical findings. In particular, the model does not explain the behavior of large otariids and small phocids. Thus, maternal metabolic requirements alone appear insufficient to explain observed lactation patterns. In the light of our results, we discuss more generally the scope and limitations of optimality models when applied in a comparative framework to a group of related species. 相似文献