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61.
2000年中国大陆地震灾害评述   总被引:5,自引:2,他引:3  
在列出2000年中国5级以上地震目录的基础上,结合有关省(自治区-直辖市)地震局的地震灾害评估资料,总结了2000年中国大陆地震灾害的主要数据和特性。最后,对1990-2000年与1980-1989年两个时间段中国大陆地震灾害的相应数据和特性进行了比较。  相似文献   
62.
Austal 2000应用于国内“烟塔合一”类项目大气影响评价   总被引:2,自引:0,他引:2  
简述了德国"烟塔合一"类大气污染扩散模式,以及相关模式Austal 2000的应用方法,修正了气象参数以适合本地化应用。以天津某电厂为实例,将Austal 2000模式"烟塔合一"和烟囱排烟方式的计算结果进行了对比分析。结果表明,在进行本地化修改后,Austal 2000模式适用于国内有关项目大气预测评价,但从环境影响角度考虑,"烟塔合一"相对于高烟囱排放方式没有明显优势,应用时需慎重。  相似文献   
63.
Despite repeated calls to action, proposals for urban conservation are often met with surprise or scepticism. There remains a pervasive narrative in policy, practice, and the public psyche that urban environments, although useful for engaging people with nature or providing ecosystem services, are of little conservation value. We argue that the tendency to overlook the conservation value of urban environments stems from misconceptions about the ability of native species to persist within cities and towns and that this, in turn, hinders effective conservation action. However, recent scientific evidence shows that these assumptions do not always hold. Although it is generally true that increasing the size, quality, and connectivity of habitat patches will improve the probability that a species can persist, the inverse is not that small, degraded, or fragmented habitats found in urban environments are worthless. In light of these findings we propose updated messages that guide and inspire researchers, practitioners, and decision makers to undertake conservation action in urban environments: consider small spaces, recognize unconventional habitats, test creative solutions, and use science to minimize the impacts of future urban development.  相似文献   
64.
Understanding threats acting on marine organisms and their conservation status is vital but challenging given a paucity of data. We studied the cumulative human impact (CHI) on and conservation status of seahorses (Hippocampus spp.)—a genus of rare and data-poor marine fishes. With expert knowledge and relevant spatial data sets, we built linear-additive models to assess and map the CHI of 12 anthropogenic stressors on 42 seahorse species. We examined the utility of indices of estimated impact (impact of each stressor and CHI) in predicting conservation status for species with random forest (RF) models. The CHI values for threatened species were significantly higher than those for nonthreatened species (category based on International Union for Conservation of Nature Red List). We derived high-accuracy RF models (87% and 96%) that predicted that 5 of the 17 data-deficient species were threatened. Demersal fishing practices with high bycatch and pollution were the best predictors of threat category. Major threat epicenters were in China, Southeast Asia, and Europe. Our results and maps of CHI may help guide global seahorse conservation and indicate that modeling and mapping human impacts can reveal threat patterns and conservation status for data-poor species. We found that for exploring threat patterns of focal species, species-level CHI models are better than existing ecosystem-level CHI models.  相似文献   
65.
As the area covered by human-modified environments grows, it is increasingly important to understand the responses of communities to the novel habitats created, especially for sensitive and threatened taxa. We aimed to improve understanding of the major evolutionary and ecological processes that shape the assemblage of amphibian and reptile communities to forest modifications. To this end, we compiled a global data set of amphibian and reptile surveys in natural, disturbed (burned, logged), and transformed (monocultures, polyspecific plantations) forest communities to assess the richness, phylogenetic diversity, and composition of those communities, as well as the morphological disparity among taxa between natural and modified forest habitats. Forest transformations led to a diversity reduction of 15.46% relative to the statistically nonsignificant effect of disturbances. Transformations also led to a community composition that was 39.4% dissimilar to that on natural forests, compared with 16.1% difference in disturbances. Modifications did not affect the morphological disparity of communities (p = 0.167 and 0.744), and we found little evidence of taxon-specific responses to anthropic impacts. Monocultures and polyspecific plantations detrimentally affected the conservation and ecological value of both amphibian and reptile communities and altered the evolutionary processes shaping these communities, whereas forests with lower impact disturbances might, to some extent, serve as reservoirs of species. Although different mechanisms might buffer the collapse of herpetological communities, preserving remaining natural forests is necessary for conserving communities in the face of future anthropic pressures.  相似文献   
66.
67.
Laursen K  Kristensen PS  Clausen P 《Ambio》2010,39(7):476-485
We assessed the blue mussel Mytilus edulis fishery management scheme introduced in 1994 in the Danish Wadden Sea that regulate fishing vessels, fishery quota, set-aside for mussel-eating birds and established zones closed to mussel fishery. The results showed (i) a reduction in the blue mussel biomass and mussel bed areas in zones closed to fishery, (ii) decrease in eiders Somateria mollissima numbers and increase or stable numbers for oystercatcher Haematopus ostralegus and herring gull Larus argentatus and (iii) that energy estimations based on ecological food requirements for the mussel-eating birds should be at least three times larger, than the amount set-aside in the mussel management scheme. It is concluded that the mussel management scheme had been unable to stabilize or increase the blue mussel stocks and to secure stable or increasing numbers for all target bird species. Thus, it is recommended to revise the present blue mussel management scheme in the Danish Wadden Sea, to continue and improve mussel stock and bird surveys, and to consider novel studies of the mussel-eating birds’ energetics for improved set-aside estimates and future assessments.  相似文献   
68.
European forest policymaking is shaped by progressing European integration, yet with notable ideological divisions and diverging interests among countries. This paper focuses on the coalitional politics of key environmental forest issues: biodiversity conservation, timber legality, and climate protection policy. Combining the Advocacy Coalition Framework and the Shifting Coalition Theory, and informed by more than 186 key informant interviews and 73 policy documents spanning a 20-year timeframe, we examine the evolution of coalitional forest politics in Europe. We find that the basic line-up has remained stable: an environmental coalition supporting EU environmental forest policy integration and a forest sector coalition mostly opposing it. Still, strategic alliances across these coalitions have occurred for specific policy issues which have resulted in a gradual establishment of an EU environmental forest policy. We conclude with discussion of our findings and provide suggestions for further research.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01644-5.  相似文献   
69.
王雷 《干旱环境监测》2002,16(4):248-250
介绍了EXCEL2000运用规划求解解决环境保护中出现的多约束条件、多变量问题的方法。  相似文献   
70.
主要介绍了CAXA电子图板和AutoCAD2 0 0 0在电刷端盖压铸模设计中的使用方法 ,论述了电刷端盖压铸模设计中涉及的压铸机选择 ,分型面选择和浇注系统的设计等技术问题。  相似文献   
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