L'archivage des activités humaines par les neiges et glaces polaires : le cas du plomb

The investigation of the occurrence of lead in dated snow and ice from Greenland and Antarctica has played a major role in our understanding of the history of the pollution of the atmosphere of our planet by this metal. Such studies have however proved to be very demanding, mainly because of the extreme purity of polar snow and ice. Reliable measurements can be obtained only if ultra-clean and highly sensitive procedures are used, as pioneered by Clair Patterson. The Greenland data show evidence of large-scale pollution of the atmosphere of the Northern Hemisphere for lead as early as two millennia ago during Greco–Roman times, especially because of mining and smelting activities in southern Spain. It peaked at the end of the 1960s, with lead concentrations in snow about 200 times higher than natural values, before declining during recent times because of the fall in the use of leaded gasoline. Lead pollution in Antarctica was already significant at the end of the 19th century as a consequence of whaling activities, the traffic of coal-powered ships crossing the Cape Horn, and mining activities in South America, South Africa and Australia. After declining because of the opening of the Panama Canal, the great economic depression and World War II, it reached a maximum during the 1980s, with lead concentrations 20 times higher than natural values. Other studies focus on past natural variations of lead in ancient ice dated from the last climatic cycles. To cite this article: C. Boutron et al., C. R. Geoscience 336 (2004).     

The Mount Parnitha (Athens) Earthquake of September 7, 1999: A Disaster Management Perspective

Natural Hazards - Strong earthquakes in the proximity of densely inhabited urban areas pose one ofthe most complicated disaster management situations faced by societies today. Herethe experience...     

1951-2006年黑龙江省积雪初终日期变化特征分析

利用黑龙江省1951-2006年积雪初终日期资料, 采用统计方法研究了黑龙江省积雪初终日期的时空变化特征. 结果表明: 黑龙江省多年平均有5.5个月的可积雪期, 积雪初日北早南晚, 南北相差1个月;终日南早北晚, 南北相差1.3个月. 积雪初日推后1.9 d·(10a)~(-1), 终日提早1.6 d·(10a)~(-1). 积雪初/终日期的退后/提前主要在较低纬度的平原地区.     

对未来防洪减灾形势和对策的一些思考

简要介绍了20世纪90年代我国大江大河的防洪形势。重点指出:河道萎缩,江河泄洪能力下降,行洪水位抬高,城市水灾突出,洪涝矛盾加重和水灾损失急剧增加的特点。探讨了防洪减灾的目标和标准,在进行防洪策略历史回顾的基础上,阐述了防洪减灾对策和基本措施方向。     

集安市净水厂滑坡灾害防治措施

集安市净水厂滑坡灾害位于丘陵区前缘,形成原因为大气降水入渗、风化裂隙水及净水厂渗漏水,改变了上覆松散岩层稳定性。滑坡为土质滑塌、滑动面为基岩面。防治工程措施为排水孔、排水沟、挡土墙。     

论气候变暖背景下干旱和干旱灾害风险特征与管理策略简

The drought is a most severe natural disaster worldwide, which leads to great risk in human being. The drought disaster and risk have more prominent because of obvious climatic warming in the last hundred years. At present, the understanding of the internal laws of the occurrence of drought and drought risk is not comprehensive, and the recognition of the characteristics of the drought and drought risk under climatic warming is obscure. In this paper, we summarized systematically the domestic and overseas research progress of the drought and drought disaster risk, introduced the principle of the drought disaster transfer process and the essential features of drought disaster, analyzed synthetically the main characteristics and interactions among the key factors of the drought disaster risk, discussed the effect of climatic warming on drought and drought disaster risk, and probed into the basic requirement of drought disaster risk management. Above all, we provide the main protective measurements of the drought disaster and the main strategy of drought disaster risk management.     

基于熵权-正态云模型的泥石流灾害易发性评价

近年来,由于极端天气事件频发和工程建设活动加剧,泥石流灾害对人类的威胁愈加严峻。因此,在综合分析泥石流灾害发育特征及形成机理的基础上,进行泥石流灾害易发性评价对防灾减灾工程活动具有指导意义。选取沟谷岸坡坡度、沟床纵坡比降、植被覆盖率、单位面积固体物源储量、汇水面积、雨季降雨量建立评价指标体系,采用熵权法确定评价指标权重,将泥石流灾害易发性分为高易发、中易发、低易发和不易发四级,建立基于正态云模型的泥石流灾害易发性评价方法,并以西秦岭地区5条泥石流沟为例验证了该评价模型的合理性。进一步将该模型用于陕西吴堡井沟泥石流灾害易发性评价,结果表明井沟泥石流具有中易发性,评价结果与实际相符。     

GS-1型滑坡光纤多参数监测系统的研究

开发一种自动化地质灾害滑坡光纤多参数监测系统,采用基于光纤光栅的反射中心波长随光纤光栅所受的应变或温度的改变产生移动,其波长移动量的多少直接反映应变或温度变化大小的工作原理。利用光纤光栅封装结构的变化,实现应变、应力、压力、温度、位移、振动等多种参量的测试;对多个光纤光栅的中心波长进行排布上的设计,则实现多点的准分布式测量,推动地质灾害监测技术的进步。     

雪冰中NO_3~-浓度记录的研究进展

NO3-是雪冰中含量最高的含氮无机离子,雪冰中NO3-浓度记录的解读已成为研究全球变化的重要内容之一.近年来国内外已经就极地与中低纬高海拔地区雪冰中NO3-浓度记录开展了大量的研究,关于NO3-所指示的环境意义形成了一系列的认识.从雪冰中NO3-的可能性来源(包括太阳活动、陆源粉尘、闪电等自然源以及其他人类源)、时空变化特征以及气-雪-冰界面转化过程等方面综述了近年来该领域的研究成果,并结合全球变化的背景对其研究前景进行了展望.     

湖北武汉典型地区岩溶发育特征分析

本文在分析以往地质资料和完成的武汉市1∶5万岩溶塌陷调查成果的基础上,从武汉市岩溶发育的形态及规模、不同岩溶条带、不同构造条件、不同地层、不同埋深和不同地貌七个方面,分别系统总结了武汉市典型地区岩溶发育的特征。区内岩溶总体中等发育,岩溶形态主要为溶隙、溶孔以及小规模溶洞;在水平方向上存在5个走向NWW—SEE、各自相对独立的碳酸盐岩条带,其中白沙洲条带岩溶最为发育,在垂直方向上浅层溶蚀发育;各地层的岩溶发育强度依次为P2q>T1d>C2h+d>T1-2j;在褶皱核部或转折端、断层带附近、长江一级阶地、山前补给局部地区等地下水交替循环强烈地带和可溶岩与非可溶岩接触带,岩溶发育相对强烈。结论可为武汉市岩溶塌陷地质灾害防治提供地质基础支撑。