Environmental impact of the MV CITA on the foreshore of Porth Hellick, Isles of Scilly     

Smith NA 《Marine pollution bulletin》2004,49(11-12):1105-1108

The grounding of the container feeder vessel MV CITA on Newfoundland Rocks, Isles of Scilly, had an effect on the surrounding biota and benthic environment. Included in the CITA's cargo were five 40 ft containers holding pallets of polyester film used in the production of audio and visual recording tapes. The wreckage presented a minor but potentially chronic source of pollution through the delayed release of polythene film, which was left on the seabed as it was considered insufficiently valuable to warrant salvage. The polythene disintegrated and was washed upon the foreshore of Porth Hellick in minute shreds. The adjacent foreshore and two control sites within the islands were analysed using a 5-strand line and vegetation survey with 10 random quadrats within each line to determine the environmental impact of the polythene.  相似文献   

The crystalline complexes of Hamadan (Sanandaj–Sirjan zone, western Iran): metasedimentary Mesozoic sequences affected by Late Cretaceous tectono-metamorphic and plutonic events     

Aliakbar Baharifar  Hossein Moinevaziri  Herv Bellon  Alain Piqu 《Comptes Rendus Geoscience》2004,336(16):1443-1452

The Hamadan area is characterised by various metamorphic rocks where the slates yielded Jurassic fossils. The entire column, representing the Mesozoic from at least the Jurassic to the Mid-Cretaceous, has been affected by tectono-metamorphic events and the emplacement of Late Cretaceous granitic rocks. A timing of these events is based on the ⁴⁰K–⁴⁰Ar ages carried mainly on separated amphiboles, biotites and muscovites, and interpreted as the ages of their isotopic closure. Results are ranging between 91 and 70 Ma. To cite this article: A. Baharifar et al., C. R. Geoscience 336 (2004).

Résumé

La région de Hamadan expose des roches métamorphiques dont les termes les moins transformés contiennent des fossiles jurassiques. Au cours du Crétacé supérieur, elle a été affectée par un événement tectono-métamorphique régional et elle a été le siège d'une activité plutonique. Les résultats des datations ⁴⁰K–⁴⁰Ar des amphiboles et des micas séparés des roches métamorphiques et plutoniques qui s'étagent entre 91 et 70 Ma montrent l'importance de ces événements et leur étalement au cours du Crétacé supérieur. Pour citer cet article : A. Baharifar et al., C. R. Geoscience 336 (2004).  相似文献   

Discovery of the largest impact crater field on Earth in the Gilf Kebir region, Egypt     

Philippe Paillou  Ahmed El Barkooky  Aly Barakat  Jean-Marie Malezieux  Bruno Reynard  Jean Dejax  Essam Heggy 《Comptes Rendus Geoscience》2004,336(16):1491-1500

Using orbital imaging radar, we have detected a large number of circular structures in the southwestern Egyptian desert, covering more than 4500 km² close to the Gilf Kebir plateau in sandstones of Upper Cretaceous. Fieldwork confirmed that it is a new impact crater field: 13 craters from 20 m to 1 km in diameter were studied. The impact origin is confirmed by the observation of shock-related structures, such as shatter cones and planar fractures in quartz grains of breccia. Considering the extension of the crater field, it was possibly created by several meteorites that broke up when entering the atmosphere. To cite this article: P. Paillou et al., C. R. Geoscience 336 (2004).

Résumé

À partir d'images satellites issues de systèmes radar, nous avons détecté un grand nombre de structures circulaires dans le Sud-Ouest du désert égyptien, s'étendant sur plus de 4500 km² à l'est du plateau du Gilf Kebir, dans des grès du Crétacé supérieur. Une étude sur le terrain a permis de vérifier qu'il s'agit d'un champ d'impacts météoritiques jusque là inconnu : 13 structures, d'un diamètre compris entre 20 m et 1 km, ont été reconnues comme cratères d'impact. La présence d'un grand nombre de cônes de percussion et de brèches dans lesquelles des quartz choqués à structures planaires ont été observés confirment l'hypothèse de l'impact. Considérant l'extension du champ d'impact, il a probablement été créé par plusieurs météorites qui se sont fragmentées dans l'atmosphère terrestre. Pour citer cet article : P. Paillou et al., C. R. Geoscience 336 (2004).  相似文献   

Not in my back yard! Sports stadia location and the property market     

Larissa E Davies 《Area》2005,37(3):268-276

In recent years sports stadia have been built in the UK, not only for their intended sporting purpose but with the twin aim of stimulating economic and physical regeneration. However, proposals to locate stadia in urban areas often prompt a negative reaction from local communities, fearing a decline in property prices. This paper will use a case study of the Millennium Stadium in Cardiff and the City of Manchester Stadium to illustrate that in contrast to this widely held belief, sports stadia can actually enhance the value of residential property. Furthermore, it will argue that stadia also contribute indirectly to property value through the creation of pride, confidence and enhanced image of an area.  相似文献   

大同地区暴雨的天气分型及其成因的初步分析研究   总被引：2，自引：0，他引：2       下载免费PDF全文

刘建国  胡建军  王丽莉 《山西气象》2004,(2):11-14

根据大同市所辖8个县气象站点自有气象记录以来的暴雨资料，应用天气学及气候学等原理，对大同地区暴雨的天气气候特征和形成机制进行了系统的分析与研究，得出了相关结论。  相似文献   

基于T213数值产品的安康降水分县预报释用          下载免费PDF全文

党红梅  石明生  周义兵  张波 《山西气象》2004,(2):15-16

将临汾市尧都区1954年至2001年小麦产量年增量和其全生育期降水量进行同步统计分析得出：小麦生产全生育期降水量大于同期降水平均值20％，则绝大多数是增产年；小麦生育期降水量少于同期降水平均值50％，则是欠收年；当小麦全生育期降水量在同期降水平均值-50％至20％之间时，小麦是增产?或是减产，由其它影响小麦产量因素决定。  相似文献   

SARS流行期的气象特征及其影响     

张强  杨贤为  叶殿秀  肖风劲  陈正洪 《南京气象学院学报》2004,27(6):849-855

对2003年3—6月我国SARS(Sever Acute Respiratory Syndrome，严重急性呼吸道综合症)发病人数最多的北京、香港逐日病例和有关气象因子进行了对比分析，结果表明：气温、气压的走向和SARS发病率有很好的关系；相对湿度高、云量多和日照少是两地高发期的共同特点；冷空气活动对SARS疫情的流行有诱发推动的作用。通过高发期逐日发病人数和气象要素随基准值变化的对应关系设计了综合指数，分别计算了两地气温因子的高危指标，结果显示，两地日平均气温和日最低气温指标相差了3℃和7℃，两地日最高气温指标均为24～27℃。  相似文献   

战略环境评价的若干理论问题的探讨   总被引：3，自引：0，他引：3  

王世亮  梁立乔 《云南地理环境研究》2004,16(3):77-80

战略环境评价(简称SEA)是环境影响评价(简称EIA)研究领域的前沿课题。中国对SEA的研究始于20世纪90年代，起步较晚。在了解SEA的概念、特点的基础上，阐述了SEA与项目EIA在评价方法、评价内容上是有所差异的，在评价程序和步骤上是有共同点的。SEA是项目EIA的深化和提高。目前在中国进行EIA的过程中，EIA的局限性和所反映出的问题日益明显，为了提高中国EIA的针对性、科学性和有效性，应积极开展SEA的研究和实践。  相似文献   

Impact of habitat heterogeneity on plant community pattern in Gurbantunggut Desert     

QIAN Yibing  WU Zhaoning  ZHANG Liyun  SHI Qingdong  JIANG Jin  TANG Lisong 《地理学报》2004,14(4):447-455

This paper reports a geomorphologic landscape investigation, vegetation survey and soil sampling at 14 sites across the Gurbantunggut Desert between 87o37'09'-88o24'04'E and 44o14'04'-45o41'52'N. The study encountered 8 species of low trees and shrubs, 5 of perennial herbs, 8 of annual plants and 48 of ephemeral and ephemeroid plants. These species of plants represent one-third of the species found in the Gurbantunggut Desert, and their communities make up a large proportion of desert vegetation with great landscape significance. In the investigation we found that the plant communities are accordingly succeeded with the spatial variation of macro-ecoenvironment. Using Principal Component Analysis (PCA) and Correlation Analysis (CA) we found that the micro-ecoenvironment heterogeneity of aeolian sandy soil's physical and chemical properties such as soil nutrient, soil moisture, soil salt, pH etc. only impacted the diversity of herb synusia (PIEherb) of the desert, with a negative correlation. Meanwhile, the impact of microhabitat on the plant community pattern with an antagonistic interaction made vegetation's eco-distribution in a temporary equilibrium.  相似文献   

无人工作面开采坚硬顶板冲击运动的3DEC数值模拟研究   总被引：2，自引：0，他引：2  

刘传孝 《岩土力学》2004,25(Z2):285-288

分4个阶段模拟了无人工作面开采坚硬顶板采场顶板的运动规律.第1阶段,坚硬顶板的悬而不落是下一区段无煤柱开采的隐患.开采范围达到8 000 m2时的第2阶段,采场坚硬顶板的冲击性垮落,使工作面前方煤体及巷道既已形成的高应力区骤然释放.开采范围继续扩大的第3阶段和第4阶段,坚硬顶板从整体大范围冲击性运动向周期性分段运动转化.北京矿务局木城涧煤矿无人工作面坚硬顶板在采场面积约为8 000 m2的初次冲击性垮落,验证了3DEC理论研究结论,其强制放顶等防冲措施实施的最佳时机为第2阶段的开采活动结束之前.  相似文献