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1.
晏启祥  段景川  刘罡  耿萍 《地震学刊》2014,(2):168-172,179
基于层次分析法、专家调查法和模糊评价法,对风积沙隧道塌方风险源因素进行识别,提出了工程地质因素、水文地质因素和施工设计因素三大类风险源。分析了各类风险源下具体风险因素的权重以及评价集,结合神木一号风积沙隧道的具体特点,对其塌方风险进行了评价。研究表明:影响风积沙隧道塌方风险的主要因素是施工设计因素,而施工设计因素中,超前支护类型这一二级风险因素又是风积沙隧道塌方与否的决定性条件。  相似文献   

2.
近年来高分辨率遥感技术快速发展,其在灾害研究领域的应用也越来越广。将遥感技术用于建筑群在地震灾害中的脆弱性和损失风险分析,不仅能保证建筑物类型和数量调查更新的时效性,而且有利于进行不同时期损失风险的对比分析,以便揭示震灾损失风险的变化规律。通过分析高分辨率建筑群的遥感影像特征,设计了一套提取建筑物属性信息(高度和面积)的方法,并通过实地调查验证了其可行性;将提取的建筑群属性信息与传统的震灾风险分析模型相结合,即可实现对研究区建筑群在地震灾害中的脆弱性和损失风险分析。以唐山市区和9个乡镇2009年的建筑物为研究对象,提取了它们的属性信息,在设定地震烈度情景下,分析了这些建筑物在地震灾害中的脆弱性和损失风险。  相似文献   

3.
防洪工程作为人类抵御洪灾的首选手段,为人们提供了保障,但人们对其风险认知还存在一定的偏差。本文从公众层面入手,在我国历史上洪灾最严重的两大流域—长江流域和黄河流域,分别选取岳阳沿洞庭湖区和开封沿黄河地区为研究区,调查公众对当地防洪工程的信赖状况和水灾风险认知情况,回收有效样本831份。据此分析影响防洪工程信赖的因素和工程信赖对公众风险认知的影响。研究发现,公众对防洪工程的信赖度较高,区域趋同性明显;公众对工程信赖的程度,因居住地与风险源的距离、性别、年龄和家庭劳动力结构的不同而存在差异;同时,对防洪工程的过于信赖,会降低公众对洪灾的恐惧心理和警惕性,并使得公众产生消极和积极并存的应对灾害的行为倾向。洪灾多发地区应建立大型洪灾、巨灾的风险防范和洪水保险机制,完善我国的再保险制度;政府在高风险区的分区域管理过程中,应以大局为重;构建"文化自觉"的科学防灾文化观,正确引导公众认识到工程措施能力的限度,扭转在工程信赖基础上的风险认知偏差。  相似文献   

4.
研究震灾风险认知及其影响因素有助于从公众视角揭示风险潜在因素,为降低灾害风险提供决策依据.本文以新疆的喀什、乌鲁木齐为研究区,通过问卷调查方式,采用假设检验和相关分析等统计方法,研究影响公众的临震心理、风险估计、地震知识水平、防震意愿及行为等震灾风险认知的因素.结果表明:影响因素包括性别、教育水平、收入水平、家庭结构、房屋结构、居住区危险性等;因素之间互相联系与风险认知因子形成正、负反馈链,其中收入水平影响了风险感知是否能转化为防减灾的积极行为.并在灾害风险分析的基础上提出了减轻地震灾害风险的对策建议.  相似文献   

5.
基于大量强透水砂层盾构施工工程事故现场调研及资料分析,建立大样本数据库并构建强透水砂层盾构施工风险事故树,以分析风险源及各自权重;基于模糊综合评价法探究强透水砂层盾构施工风险评估方法,推导出各风险因素对风险发生概率和损失的评价矩阵,从机理控制层面提出风险控制措施,并以广州某强透水砂层盾构工程实施验证。研究表明,施工风险主要为管片破裂、隧道上浮、渣土喷涌及地表塌陷等,风险发生概率与相应损失程度均可划分为5个等级。可通过加强管片拼装质量、改善上覆土层工程特性、渣土改良及装置改进等风险规避策略,有效控制施工风险,并结合风险规避、保留及转移等3种策略对地表塌陷风险进行有效控制。  相似文献   

6.
SOTEM响应特性分析与最佳观测区域研究   总被引:4,自引:2,他引:2       下载免费PDF全文
电性源短偏移距瞬变电磁法(SOTEM)是目前研究和应用较为广泛的一种人工源时间域电磁法工作装置,对深部资源地球物理精细探测具有一定的实际意义.为了深入理解方法内涵并更好地进行推广应用,本文基于电性源瞬变电磁一维正演理论,研究了SOTEM地下感应电流扩散、多分量电磁响应平面分布、多偏移距衰减等特性,然后根据上述特性研究了SOTEM的最佳观测区域.研究结果表明:电性源在地下可以产生水平和垂直两个方向的感应电流.其中,水平感应电流又分为上部水平感应电流和下部水平感应电流(又称作返回电流),水平感应电流的极大值主要集中于发射源附近并垂直向下扩散;垂直感应电流极大值沿与地面呈45°角的方向向下、向外扩散,并且具有较低的振幅和较快的扩散速度.电性源激发的六个方向的电磁场分量都具有一定的探测能力,但是考虑到地面观测的方便性和各分量的传播、分布特点,大多数情况仅利用垂直磁场分量Hz(B/t)和水平电场分量Ex.其中,Hz仅对低阻目标体敏感,且敏感区域位于赤道向区域,并集中在发射源附近;Ex既对低阻体敏感也对高阻体敏感,对低阻体的敏感区域位于赤道向区域,而对高阻体的敏感区域位于轴向区域,并且敏感区域距发射源的距离与目标体埋深和围岩电性有关.  相似文献   

7.
地震灾害是中国社会稳定和经济发展的重大风险源,而地震风险控制是社会多元主体参与的复合型风险治理模式.本课题以风险理论为基础,在调查问卷、访谈、座谈、考察调研和现行文献研究的基础上,通过对地震重点监视防御区政府职能履行现状的研究,分析影响地震重点监视防御区制度实施的各种因素,进而提出加强地震重点监视防御区中央和地方政府社会管理和公共服务职能的政策性措施与建议,旨在完善地震重点监视防御区地震风险管理制度,形成政府社会共同应对地震社会风险,降低社会易损性,从而达到控制地震社会风险的目的.  相似文献   

8.
陈伟  黄宗林  方烨  林琛 《华南地震》2022,42(1):52-60
通过对永安—晋江断裂带开展致灾因子风险调查,逐一查明带内各次级断裂的规模、产状、活动性质和最新活动时代,结合地震活动特征和构造应力场,综合判定调查区内的发震构造和致灾因子,评价各致灾因子的最大潜在震级.在此基础上开展致灾因子风险区划,在调查区内划分出7个地震风险源,厘定各风险源及背景源的震级上限,为响应国家自然灾害风险...  相似文献   

9.
本文在“嘉峪关市地震危险性分析”工作的基础上,以大草滩水库土石坝为例,研究了坝体震害预测的方法。用动力非线性有限元法计算并分析了坝体的非线性动力特性,给出了50年超越概率为10%和2%两种风险水平下,坝体表面可能出现的拉裂区域和坝体内可能出现的塑性破坏区域,并给出了有代表性的一些地点的加速度时程和动剪应力时程。本文还用拟静力法对坝体的整体稳定性进行了分析计算,给出上述两种风险水平下,在可能遇到的各种情况下,坝体的整体安全可靠性能。  相似文献   

10.
基于香港地区5个海陆联测子台的噪声分析数据,结合人工地震的观测结果,对该区域噪声水平和传导机制做进一步的研究,并分析了该台阵的地震监测水平。结果表明:香港地区普遍噪声水平偏高,噪声测试结果反映了该区域的噪声污染较为严重,但在城市边缘地带仍可进行地震观测;台阵对于天然地震的监测效果较好,对人工地震(爆破)的监测效果较差。根据噪声水平和波形记录质量,可进一步推断城市噪声污染和海水对爆破等产生的面波的削减作用较为明显。这一实验过程和结果对分析香港地区的环境噪声水平,地震观测结果可信度和介质物性都有借鉴意义。  相似文献   

11.
The number of airborne pollution accidents is second only to that of water-borne pollution accidents, in recorded environmental disasters. Acute casualties and public health costs have prompted many airborne pollution risk analyses. To date, few assessment methods have been carried out at regional-scale to quantify acute airborne pollution risk. Herein, a Hybrid Simulation and Risk Analysis approach, involving a systematic combination of simulation, risk ranking, and standardized analysis, is proposed at regional scale. Gaussian and heavy-gas models are utilized in the simulation process, and acute exposure limits preferentially adopted in the risk analysis. The case study shows that 34 of 243 townships in Zhangjiakou City of north China, one of the twin cities selected to host the 2022 Winter Olympics, are threatened by airborne risk sources. It is found that the accidental air pollution risk is comparatively higher in the Xuanhua and Wanquan conurbations. High-risk chemical enterprises (312–432 risk scores) are mostly located near urban areas with high population density where many people are vulnerable receptors to potential air pollution accidents. The resulting risk map indicates that acute airborne pollution from Zhangjiakou would not be a threat either to the proposed Olympic site at Chongli or to downwind Beijing.  相似文献   

12.
The proposed hydroelectric project on the Yangtze Gorges will be one of the largest power stations in the world.The problem of induced seismicity to the project has attracted much attention throughout China and the world.A research program has been carried out by the State Seismological Bureau of China.Based on the size of the reservoir and the lithology,geological structure,permeability,stress state,and previous seismicity in the region,the potential risk of reservoir-induced seismicity has been estimated.The results suggest that,after impoundment in the reservoir area,the possibility of induced seismicity cannot be completely ruled out.The areas with potential risk may be in some gorges composed of karstified carbonate and plutonic granite around the dam site.However,the magnitude is expected to be limited owing to the small dimension of the induced seismogenic faults.  相似文献   

13.
Comprehensive flood risk assessment requires enhanced understanding of the coevolution of the river and its floodplain occupation. Paleoflood analysis to determine flood prone areas in combination with numerical simulations to estimate flood hazard and a historical analysis of urban development to consider the evolution of exposure to floods is a possible way forward. The well‐documented 2006 extreme flood in the Biobío River system and the impacted metropolitan area of Concepción, Chile (~1 million inhabitants) was used as a complex scenario to test the reliability of the proposed method. Results showed that flood prone areas determined with hydro‐geomorphological methods are consistent with those computed with numerical models based on detailed digital elevation models. The flood generation via superficial flow pathways resulting in inundated areas could explain that rivers tend to reactivate paleochannels in extreme conditions. Urban development progressively increased the city's exposure to floods from 0 ha in 1,751 to 1,363 ha in 2006 evidencing a lack of appropriate flood risk management. The 100‐year peak discharge resulted in a high flood risk for about 5% of the total urbanized area of Concepción, and higher discharges are likely to reactivate a paleochannel that crosses the current city centre. We conclude that the proposed paleo hydro‐geomorphology, hydraulic, and urban planning multimethod approach is a necessary tool to enhance understanding of flood risk in complex scenarios to improve flood risk management.  相似文献   

14.
为了弥补现有地铁火灾风险评估方法的不足,并为地铁的消防设计与管理提供量化指标,建立了以层次分析法(AHP)、专家调查法为基础,以可拓法为核心的地铁火灾风险的多级可拓评估方法,并给出了评估流程。对一地铁算例进行了评估,并根据评估结果得到地铁火灾风险的薄弱环节及管理重点。通过对比分析可知,本文方法与模糊评估方法所得的评估结果一致,从而表明:将可拓原理应用到地铁火灾风险性的评估中是合理可行的,很好地解决了地铁火灾风险评估的实际问题,本文方法可应用到相关的风险评估领域中。最后,对地铁火灾安全提出了一些建议。  相似文献   

15.
The sudden and catastrophic, or slow and continuous, release at surface of naturally occurring toxic gases like CO2, H2S and Rn poses a serious health risk to people living in geologically active regions. In general this problem receives little attention from local governments, although public concern is raised periodically when anomalous toxic-gas concentrations suddenly kill humans or livestock. For example, elevated CO2 concentrations have been linked to the death of at least 10 people in the central Italian region of Lazio over the last 20 years, while it was the CO2 asphyxiation of 30 cows in a heavily populated area near Rome in 1999 which prompted the present soil-gas study into the distribution of the local health risk. A detailed geochemical survey was carried out in an area of about 4 km2 in the Ciampino and Marino districts, whereby a total of 274 soil-gas samples were collected and analysed for more than 10 major and trace gas species. Data were then processed using both statistical and geostatistical methods, and the resulting maps were examined in order to highlight areas of elevated risk. General trends of elevated CO2 and Rn concentrations imply the presence of preferential pathways (i.e. faults and fractures) along which deep gases are able to migrate towards the surface. The CO2 and Rn anomalous trends often correspond to and are usually elongated parallel to the Apennine mountain range, the controlling structural feature in central Italy. Because of this fundamental anisotropy in the factors controlling the soil-gas distribution, it was found that a geostatistical approach using variogram analysis allowed for a better interpretation of the data. With regard to the health risk to local inhabitants, it was found that although some high risk areas had been zoned as parkland, others had been heavily developed for residential purposes. For example, many new houses were found to have been built on ground which has soil-gas CO2 concentrations of more than 70% and radon values of more than 250 kBq m−3. It is recommended that land-use planners incorporate soil-gas and/or gas flux measurements in environmental assessments in areas of possible risk (i.e. volcanic or structurally active areas).  相似文献   

16.
To identify the groundwater flow system in the North China Plain, the chemical and stable isotopes of the groundwater and surface water were analysed along the Chaobai River and Yongding River basin. According to the field survey, the study area in the North China Plain was classified hydrogeologically into three parts: mountain, piedmont alluvial fan and lowland areas. The change of electrical conductance and pH values coincided with groundwater flow from mountain to lowland areas. The following groundwater types are recognized: Ca? HCO3 and Ca? Mg? HCO3 in mountain areas, Ca? Mg? HCO3 and Na? K? HCO3 in piedmont alluvial fan areas, and HCO3? Na in lowland areas. The stable isotope distribution of groundwater in the study area also has a good corresponding relation with other chemical characteristics. Stable isotope signatures reveal a major recharge from precipitation and surface water in the mountain areas. Chemical and stable isotope analysis data suggest that mountain and piedmont alluvial fan areas were the major recharge zones and the lowland areas belong to the main discharge zone. Precipitation and surface water were the major sources for groundwater in the North China Plain. Stable isotopic enrichment of groundwater near the dam area in front of the piedmont alluvial fan areas shows that the dam water infiltrated to the ground after evaporation. As a result, from the stable isotope analysis, isotope value of groundwater tends to deplete from sea level (horizontal ground surface) to both top of the mountain and the bottom of the lowland areas in symmetrically. This suggests that groundwater in the study area is controlled by the altitude effect. Shallow groundwater in the study area belongs to the local flow system and deep groundwater part of the regional flow system. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

17.
Soil erosion is one of the major threats to the conservation of soil and water resources in the Danjiangkou Reservoir region (DRR), China. In order to describe the areas with high soil erosion risk (SER) and to develop adequate erosion prevention measures, SER in the DRR was assessed by integrating the CORINE model with GIS and RS. The main factors of soil erosion including erosivitiy, soil erodibility, topography and vegetation cover were determined from daily meteorological data, field survey soil profile data and soil sample analysis, digital elevation model (DEM), and land use and land cover (LULC), respectively. Landsat 5 TM imagery was used to generate a LULC classification. The results indicate that 59.1%, 31.2%, and 2.3% of the study area were under low, moderate, and high actual erosion risks, respectively. The results also indicate the study area is in low to moderate erosion risk level on the whole. The areas with moderate to high erosion risk continuously distributed in the southwest of the study area, and sporadically distributed in the north of the study area. Low erosion risk areas mainly located in the east. Up till now, most of the semi-quantitative models have not been applied extensively. The semi-quantitative CORINE model was mostly applied in the European and Mediterranean countries, while spatial comparison of actual SER map and field investigation in this study indicates that the CORINE model can be applicable in the monsoon region of China.  相似文献   

18.
房屋建筑数据是地震重点危险区预评估工作的基础,需基于获取到的房屋建筑信息开展人员伤亡、经济损失、救援物资需求等预评估工作。历年地震重点危险区预评估工作能够通过现场调查得到的房屋建筑信息占比极小,仅能进行抽样调查。因此,为批量完成危险区内全部房屋建筑损失估算,需基于遥感影像获取房屋建筑矢量数据,并建立数据库。为实现全国地震重点危险区预评估工作中大批量建筑物矢量化数据的快速获取,本文采用基于遥感影像的建筑物空间分布数据批量获取方法,得到地震重点危险区内建筑物空间矢量数据,结合现场抽样调查得到的建筑物属性信息,建立地震重点危险区建筑物空间分布数据库,进而为地震重点危险区灾害损失预评估工作提供数据基础。本文采用的方法可广泛应用于地震重点危险区房屋建筑信息获取工作中,可提高工作效率,降低工作成本,提升预评估工作的科学性和准确性。  相似文献   

19.
The hydrogeological conditions in the North China type coal mine area are complex and diverse, and water gushing accidents are frequent. Quickly and accurately identifying the source of water in these incidents is necessary to reduce the harmful effects of mine floods. Taking the Pingdingshan mining area as an example, what chemical composition data from each of the main aquifers was collected and a mine gushing water source model, based on Hierarchical Cluster Analysis—Principle Component Analysis—Entropy Weighted Membership (HCA-PCA-EWM), was established. First, typical water sample data from an aquifer were selected by systematic cluster analysis. Then, the remaining water samples were randomly divided into training and prediction samples. Principal component analysis was used to reduce the dimension of water chemical components in training samples. Finally, the discriminant model of the water gushing source was established on the basis of the entropy weight-membership degree principle. The accuracy of the HCA-PCA-EWM discriminant model approached 100%, while those of traditional PCA-Fisher and PCA-EWM discriminant models were 62.5 and 87.5%, respectively. From the above, the HCA-PCA-EWM discriminant model can effectively select typical aquifer water samples, significantly improve the accuracy of the model, and provide a theoretical basis for the effective identification of mine water gushing sources.  相似文献   

20.
新疆是我国大陆地区开展年度地震趋势预测最早的省区之一,自1973年以来累计划定105个年度地震危险区。整理总结新疆年度地震危险区的时、空分布及地震对应情况,结果表明年度地震预测总报准率为26%,相当于全国的平均预测水平;年度危险区预测数量与预测面积基本成正比;危险区划定次数最多的构造区域是北天山中西段,以下依次是柯枰块区、乌恰-喀什地区、南天山东段、乌鲁木齐地区、西昆仑地区和阿勒泰-富蕴地区,其中北天山中西段和乌恰-喀什危险区的时、空继承性较强,但预测效果相对较差。对新疆年度地震危险区的历史资料进行整理和总结,能为今后更好地提高新疆年度预测水平积累一些参考经验。  相似文献   

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