汶川大地震震害特点与成因分析

2008年5月12日汶川地震造成巨大人员伤亡和财产损失.本文从工程抗震角度分析了震区房屋倒塌的原因,指出地震时房屋倒塌与否与诸多因素有关.在此基础上,分析了汶川地震震害严重的四个主要因素:震级大,烈度高,断层破裂长;震区人口稠密,房屋、路桥等人工工程多;抗震设防水平低;地震诱发地质灾害严重.最后,将汶川地震震害与1976年唐山地震震害作了对比.所得结论可供理解汶川地震震害、改进结构抗震设计参考.     

2008年瑞丽4.9级地震烈度及震害研究

给出瑞丽4.9级地震的烈度区的展布情况,详细介绍了烈度区内的建筑结构特点和震害特征,以及生命线工程和水利设施的震害,并对形成震害的原因进行了初步分析.     

活断层数据库在昆明市防震减灾工作中的应用研究

简要介绍了活断层数据库的数据成果,并对活断层数据库的成果在昆明市城市规划及生命线工程等重要设施的避让距离确定等防震减灾工作中的应用进行了初步探讨.     

珠江三角洲城市群震害损失预测初步研究

城市群是经济快速发展的产物。已有的震例表明城市群震害比单个城市的震害更为复杂、严重,对社会的影响更为巨大。阐述了珠江三角洲城市群的发展现状及其地震活动性,分析了城市群的地震灾害特点．并利用现有的震害评估模型及基础数据对珠江三角洲城市群进行震害损失模拟．结果证明城市群震害损失较非城市群更严重．并提出了防御城市群地震灾害的措施、     

江苏及邻区中小地震能量场的时空变化分析

采用随机能量场的概念,将地震活动能量场看作时间和空间的随机函数场,用自然正交函数展开的分析方法,研究江苏及邻区自1970年1月至2007年12月的中小地震(2.1≤M_L≤4.5)能量场变化特征,以及主要典型能量场的时间"权重"系数的变化特征.结果显示:前7个典型场的展开精度为0.9244.研究区内不同构造块体的地震活动能量场强度存在明显差异,其中下扬子块体的苏中、苏南地区及南黄海海域的地震背景能量值高于其他地区;从典型场的分布来看,该区域对研究区能量场的影响也最为显著.前6个主要典型场的时间"权重"系数随时间的变化幅度与研究区大部分中强震之间在时间上存在很强的相关性.     

如何看待我国地震预报研究在防震减灾中的作用

自20世纪60年代开始,地震预报研究至今已40多年,但到目前为止,仍然未取得突破性进展;而另一方面随着社会经济的迅速发展和对人的生命价值的重视,社会和民众对准确预报地震的期望十分迫切,特别是5·12汶川大地震的发生,使得一些群众对地震预报工作产生怀疑和不理解。地震预报研究到底有无作用？本文从地震灾害的特点、地震预报的难点和我国地震预报探索几十年来所取得的成效作一阐述,并对如何提高地震预报实效提出几点讨论意见。     

Elevation adjustments of paired natural levees during flooding of the Saskatchewan River

Natural levees control the exchange of water between an alluvial channel and its floodplain, but little is known about the spatial distribution and evolution of levee heights. The summer 2005 flood of the Saskatchewan River (Cumberland Marshes, east‐central Saskatchewan) inundated large areas of floodplain for up to seven weeks, forming prominent new deposits on natural levees along main‐stem channels. Measurements of flood‐deposit thickness and crest heights of 61 levee pairs show that the thickest deposits occur on the lower pre‐flood levee in 80% of the sites, though no clear relationship exists between deposit thickness and magnitude of height difference. Only 16% of the pairs displayed thicker deposits on the higher levee, half of which occurred at sites where relatively clear floodbasin waters re‐entered turbid channels during general flooding. Difference in crest elevation (ΔE) between paired levees is approximately log‐normally distributed, both before and after the flood, though with different mean values. Supplemental observations from tank experiments indicate that during near‐bankfull flows, temporally and spatially variable deposition and erosion occur on levees due to backwater effects associated with nearby channel bars and irregular rises of the channel bed forced by channel extension. During floods, preferential deposition in lows tends to even out crest heights. Copyright © 2009 John Wiley & Sons, Ltd.     

多因素控制的城镇地震灾害应急处置模型研究

随着城镇化水平的快速提高,地震灾害高风险暴露城镇数量将不断增加,震后有效的应急处置尤为重要。而当前城镇的地震应急处置主要依据平时制定的地震应急预案开展,缺乏针对性与可操作性。本文以提升城镇地震灾害应急处置能力为目的,总结以往城镇地震应急处置案例,提炼城镇地震灾害应急处置流程,结合城镇特殊的社会经济、自然地理等特点,在分析影响地震灾害应急处置关键因素的基础上,按地震烈度的不同,研究构建了具有区域特征且操作性较强的城镇地震灾害应急处置模型,为城镇地震应急处置的科学化、规范化提供了参考。     

基于国普数据的芦山县地震应急基础数据更新及其应用研究

通过研究地理国情普查数据和四川省芦山县地震应急基础数据库的数据类型、数据结构及二者间的关系,完成了地理国情普查数据向芦山县地震应急基础数据的转换与更新;并以芦山地震为例,利用城镇地震应急快速评估系统验证了更新后数据的可靠性。     

A modelling framework for evaluation of the hydrological impacts of nature‐based approaches to flood risk management,with application to in‐channel interventions across a 29‐km2 scale catchment in the United Kingdom

Nature‐based approaches to flood risk management are increasing in popularity. Evidence for the effectiveness at the catchment scale of such spatially distributed upstream measures is inconclusive. However, it also remains an open question whether, under certain conditions, the individual impacts of a collection of flood mitigation interventions could combine to produce a detrimental effect on runoff response. A modelling framework is presented for evaluation of the impacts of hillslope and in‐channel natural flood management interventions. It couples an existing semidistributed hydrological model with a new, spatially explicit, hydraulic channel network routing model. The model is applied to assess a potential flood mitigation scheme in an agricultural catchment in North Yorkshire, United Kingdom, comprising various configurations of a single variety of in‐channel feature. The hydrological model is used to generate subsurface and surface fluxes for a flood event in 2012. The network routing model is then applied to evaluate the response to the addition of up to 59 features. Additional channel and floodplain storage of approximately 70,000 m³ is seen with a reduction of around 11% in peak discharge. Although this might be sufficient to reduce flooding in moderate events, it is inadequate to prevent flooding in the double‐peaked storm of the magnitude that caused damage within the catchment in 2012. Some strategies using features specific to this catchment are suggested in order to improve the attenuation that could be achieved by applying a nature‐based approach.