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91.
滇池湖滨带湿生乔木湿地构建技术研究 总被引:3,自引:0,他引:3
采用以草本植物为主构建的湖滨湿地存在的主要问题是挺水植物繁殖速度快,生物量大,如每年不及时对死亡植株进行收割,会加快湖泊淤积速度,对湖泊水体造成二次污染;大面积湿地挺水植物的管护和收割,势必造成湿地管理强度和费用大幅提高。针对上述问题,文章重点介绍了在滇池草海湖滨带中以湿生乔木植物代替草本挺水植物的湖滨湿地构建技术现场试验研究成果,在湖滨带基底修复的基础上,选择垂柳、滇杨、中山杉、水杉、池杉和竹子等湿生植物开展现场试验,研究结果推荐适应能力较强、成活率较高和景观效果好的垂柳、中山杉为滇池湖滨带湿生乔木湿地构建的主要树种,为受损湖泊湖滨带生态修复提供借鉴。 相似文献
92.
利用龙门山断裂带及其邻近地区地震台站的远震波形记录,采用时间域迭代反褶积技术求取接收函数,并用多次反射波能量扫描求极大值和波形叠加反演的方法(H-Kappa方法)计算出台站下方的莫霍面深度和波速比。结果显示:莫霍面位于扬子地台西缘部分向西侧倾斜缓降,深度在40~48 km变化,地壳平均波速比值为1.81;都江堰、汶川、耿达一带处在龙门山推覆体范围之内的莫霍面起伏变化不大,深度在45 km左右,地壳平均波速比值为1.707 5;龙门山断裂带西侧的松潘—甘孜地块的平均地壳波速比为1.76,莫霍面深度南面部分比北面深约10 km,呈南深北浅状。 相似文献
93.
张国晖 《安全.健康和环境》2005,5(9):13-15
运用毒害区计算方法对本部贮存的氯气泄漏后扩散的半径进行估算,同时以扩散的半径作参考,提出氯气泄漏的处置方法. 相似文献
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The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal ecosystem.It is important and necessary to analyze changes of coastal landscape pattern under the influence of artificial dykes for the protection and management of coastal wetland.Our study aimed to reveal the quantitative characteristics of the coastal wetland landscape and its spatial-temporal dynamics under the influence of artificial dykes in the Yellow River delta(YRD).It was analyzed by the methods of the statistical analysis of landscape structure,five selected landscape indices and the changes of spatial centroids of three typical wetland types,including reed marshes,tidal fiats and aquaculture-salt fields.The results showed that:(1)Reduction of wetland area,especially the degradation of natural wetlands,had been the principal problem since the dykes were constructed in the YRD.The dykes created conditions for the development of artificial wetlands.However,the new born artificial wetlands were still less than the vanished natural wetlands.(2)Compared with the open area,the building of artificial dykes significantly speeded up the changes of landscape patterns and the aggravation of the landscape fragmentation in the closed area.(3)The changes of area-weighted centroids of three typical wetland landscapes were greatly affected by dykes,and the movement of the centroid of the aquaculture-salt field was very sensitive to the dykes constructed in the corresponding period. 相似文献
97.
发展海洋生态旅游是实现山东半岛蓝色经济区战略的重要途径之一。在SWOT分析的基础上,指出在山东半岛蓝色经济区发展海洋生态旅游必须明确其动力机制,坚持统筹发展战略,从生态保护、社区参与、区域统筹和产业协同四个方面采取具体的对策。 相似文献
98.
基于岩体开挖卸荷过程中力学参数变化理论的分析研究,建立卸荷岩体有限元分析模型,运用ADINA有限元分析软件对岩体进行一维卸荷数值仿真研究。根据有限元数值分析计算成果得到岩体力学参数与主卸荷方向累计开挖卸荷量间的变化关系曲线。结果表明:岩体开挖卸荷过程中,岩体力学参数变形模量、泊松比、粘聚力和内摩擦角等呈现出随开挖卸荷量的变化而发生变化的特征,随卸荷量的增大有减小的趋势,但它们不是从初始值一直减小到零,而是随卸荷量的增大减小到一定的量值后,岩体的裂隙张开、结构面的扩展到一定的程度,岩体的力学参数保持一定的量级不再减小。 相似文献
99.
Ramiz M. Mamedov Boyukagha N. Mustafayev 《Environment, Development and Sustainability》2007,9(2):131-142
In order to determine the potential for sustainable regional development of the Caspian coastal zone, a study was made for
the Khachmaz–Absheron zone of Azerbaijan. An evaluation was performed to assess the anthropogenic load on landscapes. Using
the 8-point scale offered by Isachenko [2001, Ecological Geography of Russia, Saint Petersburg University Press, Saint Petersburg]
for the indicators of agricultural, industrial, urban and integral anthropogenic loads, we did a preliminary ranking of the
provinces in the Khachmaz–Absheron zone of Azerbaijan for the each indicator taken separately. Vital statistics were used
as a supplementary indicator of environmental conditions in the region. By comparing the data for provinces with each other
and the data on Azerbaijan average, we have classified the provinces into 4 groups according to specific combinations of the
indicators. Each group of provinces has distinctive environmental conditions and features for sustainable development. The
classification makes it possible to develop certain recommendations for the regional sustainable development. Measures to
be implemented within the Azerbaijan State Program on Social and Economic Development of Regions are also discussed. In the
Khachmaz province, production of ecologically pure products is highly recommended. Special attention should be given to the
development of tourism and recreational institutions in the Khachmaz, Khizi and Devechi provinces. Recommendations for these
provinces include further development of industry on the basis of modern safe technologies. The irrigation and drainage networks
should be reconstructed. The reconstruction will make it possible to reduce water loss and to increase the productivity of
agriculture. In the Absheron province, Baku and Sumgait cities environmental systems are overloaded, and so the works at highly
polluting enterprises must be stopped, the enterprises have to be re-equipped (old filters must be changed first of all) or
relocated from the area (a decrease of environmental risk should be in the focus of attention). For improving of air quality,
green areas should increase. There is a need to reduce urban traffic density and to reconstruct highways. Use of old vehicles
must be forbidden or restricted, and transition to environmentally friendly fuel should be supported in every way possible.
It is necessary to bring the waste management system and sanitary landfills up to international standards, and to improve
the water supply and sewerage systems. 相似文献
100.
Richard J. Horwitz Thomas E. Johnson Paul F. Overbeck T. Kevin O’Donnell W. Cully Hession Bernard W. Sweeney 《Journal of the American Water Resources Association》2008,44(3):724-741
Abstract: The joint influences of riparian vegetation and urbanization on fish assemblages were analyzed by depletion sampling in paired forested and nonforested reaches of 25 small streams along an urbanization gradient. Nonforested reaches were narrower than their forested counterparts, so densities based on surface area differ from linear densities (based on reach length). Linear densities (based on number or biomass of fish) of American eel, white sucker and tesselated darter, and the proportion of biomass of benthic invertivores were significantly higher in nonforested reaches, while linear densities of margined madtom and the number of pool species were significantly higher in forested reaches. Observed riparian effects may reflect differences in habitat and algal productivity between forested and nonforested reaches. These results suggest that relatively small‐scale riparian restoration projects can affect local geomorphology and the abundance of fish. Dense vegetative cover in riparian zones and similar or analogous habitats in both forested and nonforested reaches, the relatively small scale of the nonforested reaches, and the low statistical power to detect differences in abundance of rare species may have limited the observed differences between forested and nonforested reaches. There was a strong urbanization gradient, with reductions of intolerant species and increases of tolerant species and omnivores with increasing urbanization. Interactions between riparian vegetation type and urbanization were found for blacknose dace, creek chub, tesselated darter, and the proportion of biomass of lithophilic spawners. The study did not provide consistent support for the hypotheses that responses of fish to riparian vegetation would be overwhelmed by urban degradation or insignificant at low urbanization. 相似文献