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31.
确定全国地震重点监视防御区的研究 总被引:2,自引:6,他引:2
首先阐述确定地震重点监视防御区的分级原则(分为国家级和省级),突出重点原则(重点监视防御区面积占全国或省辖面积的较小部分,而其地震损失占总和的大部分)和科学技术思路(以地震危险性预测为基础,以灾害损失的预测为依据确定地震重点监视防御区)。其次,回顾了确定1996~2005年全国地震重点监视防御区的研究成果。回顾表明,在1996~2005年间,发生在我国大陆有监测能力地区的10次强震中,有8次发生在防御区内及其邻近地区,其经济和生命损失已分别占大陆的67%和92%。最后,简要介绍为确定2006-2020年全国地震重点监视防御区而开展的研究工作,包括基于地震学、地震地质学、大地测量学、地震工程学、社会学和预测学而进行的10年尺度的中长期地震危险预测研究,以及所得到的2006-2020年全国地震危险概率预测图、地震危险性(烈度)预测图、地震灾害损失预测图和地震危险性综合指数预测图等。 相似文献
32.
本简要介绍了山西中部(32个县市)的历史地震灾害,在对建筑物的类型进行划分的基础上,用地震安全性评价的综合概率法计算了每个单元遭遇烈度的概率,根据各类建筑物的易损性矩阵和不同类型单元的人员震亡、伤率矩阵,计算得出32个单元建筑物的期望经济损失和人员伤亡期望绝对值,并对计算结果进行了分析和比较,最后提出防震减灾对策。 相似文献
33.
Aftershocks have been shown to exacerbate earthquake‐induced financial losses by causing further damage to structural and nonstructural components in buildings that have already been affected by a mainshock event and increasing the duration of disrupted functionality. Whereas seismic loss assessment under isolated events has been addressed thoroughly in previous studies, comparatively less has been accomplished in the area of loss assessment under sequences of mainshock‐aftershock ground motions. The main objective of the current study is to formulate a comprehensive framework for quantifying financial losses under sequential seismic events. The proposed framework is capable of accounting for the uncertainties in the state of structure due to accumulation of earthquake‐induced damage, the time‐dependent nature of seismic hazard in the post‐mainshock environment, and the uncertainties in the occurrence of mainshock and aftershock events. Application of the proposed framework to a 4‐story reinforced concrete moment frame shows that consideration of aftershocks could increase lifecycle earthquake‐induced losses by up to 30% compared with mainshock‐only assessments. 相似文献
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Forest soil is an important component of the natural environment, and is a primary medium for many biological activities. In this study, soil loss and displacement by excavator and bulldozer (heavy equipments) were measured on cut and fills slopes of forest roads located in Mazandaran province, lran. The volumes of soil losses were estimated by prismoidal analyses of cut and fill slopes deformation between two time treatments (under subgrading and two years later) in slope classes of 30-50% and 50-70%. Weights of soil losses were calculated by multiplying the volumes of soil losses (cm^3) to the general bulk density (1.3g/cm^3). Soil displaced area by heavy equipment was evaluated according to earth working width. Results indicated that heavy equipment has significant effect on deformation of cut slope gradient and fill slope length (p〈0.0001). During the two-year period, the cut (p〈0.0002) and fill (p〈0.0001) slope gradients were significantly deformed in different slope classes. The average soil loss by excavator and bulldozer were 160.35 t/ha·yr and 429.09 t/ha·yr, respectively. Moreover, the soil displaced area during the subgrading process by bulldozer was greater than excavator in both two slope classes (p〈0.05). Soil loss and displacement in forest roads can be rednced by applying powerful excavators in subgrading project, especially in steep terrains. 相似文献
36.
太湖丘陵地区典型坡面土壤侵蚀与养分流失 总被引:19,自引:1,他引:19
建立了基于137Cs技术的土壤侵蚀的定量模型,采用有关土壤养分流失方程,对太湖地区典型坡面的土壤侵蚀和土壤养分流失进行初步估算.结果表明,研究地区的典型坡面存在着一定的土壤侵蚀,林地各个剖面点的土壤侵蚀模数平均为1313.6 t/(km2 @a),而菜地所在的微地貌部位土壤侵蚀更达5185.68 t/(km2 @a).土壤侵蚀主要受植被覆盖和人为耕作的影响,侵蚀量的大小排序为坡麓菜地>坡中马尾松林地>竹林地>坡顶马尾松林地.选择的典型坡面存在着一定的土壤养分流失,林地有机质、全氮、全磷与全钾的平均流失量亦分别高达28.29,1.38,0.35和16.76 t/(km2 @a),养分流失量大的地貌部位的土壤有机质、全氮、全磷和全钾含量低,而土壤侵蚀微弱的坡顶林地土壤养分含量较高.菜地土壤养分流失量最大,但由于施肥作用,土壤养分含最高.太湖丘陵地区的土壤侵蚀与养分流失不仅关系到本地区土壤肥力的退化,并对太湖水体环境质量的产生影响. 相似文献
37.
1966年3月8日河北省邢台地震(M_S=6.8)震害调查资料的统计分析结果表明,地震造成人员伤亡的损失程度遵从正态的概率分布,据此初步建立起土坯墙房的生命地震易损性概率矩阵P(D_0|I)。该矩阵将可应用在地震灾害生命损失的概率预测研究中。 相似文献
38.
Alexandre Cunha Costa Saskia Foerster José Carlos de Araújo Axel Bronstert 《水文研究》2013,27(7):1046-1060
Scarcity of hydrological data, especially streamflow discharge and groundwater level series, restricts the understanding of channel transmission losses (TL) in drylands. Furthermore, the lack of information on spatial river dynamics encompasses high uncertainty on TL analysis in large rivers. The objective of this study was to combine the information from streamflow and groundwater level series with multi‐temporal satellite data to derive a hydrological concept of TL for a reach of the Middle Jaguaribe River (MJR) in semi‐arid north‐eastern Brazil. Based on this analysis, we proposed strategies for its modelling and simulation. TL take place in an alluvium, where river and groundwater can be considered to be hydraulically connected. Most losses certainly infiltrated only through streambed and levees and not through the flood plains, as could be shown by satellite image analysis. TL events whose input river flows were smaller than a threshold did not reach the outlet of the MJR. TL events whose input flows were higher than this threshold reached the outlet losing on average 30% of their input. During the dry seasons (DS) and at the beginning of rainy seasons (DS/BRS), no river flow is expected for pre‐events, and events have vertical infiltration into the alluvium. At the middle and the end of the rainy seasons (MRS/ERS), river flow sustained by base flow occurs before/after events, and lateral infiltration into the alluvium plays a major role. Thus, the MJR shifts from being a losing river at DS/BRS to become a losing/gaining (mostly losing) river at MRS/ERS. A model of this system has to include the coupling of river and groundwater flow processes linked by a leakage approach. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
39.
河北省北部地震灾害经济损失预测 总被引:1,自引:0,他引:1
地震灾害经济损失预测是震害预测的重要组成部分,在河北省北部地震危险性概率分析、建筑物、生命线工程等震害预测的基础上,确定了震害经济损失预测的各种参数,以乡(镇)、区(市辖区)为基础统计单元,采用动态预测模型,预测河北省北部2005年前震害经济期望损失:直接经济损失19.74亿元,总经济损失31.92亿元。若怀来发生5.5级和6级假想地震,震害经济损失分别为3.06亿元和4.82亿元,死亡1人和11 相似文献
40.