青藏铁路沿线地震灾害风险区划

【作者】 于斌；

【导师】 刘峰贵；

【作者基本信息】 青海师范大学 ， 自然地理学， 2010， 硕士

【摘要】 中国位于环太平洋地震带与地中海-喜马拉雅地震带的交汇处,是世界上地震活动最强烈的国家之一,属地震多发区。中国的地震活动具有频率高、分布广、强度大、震源浅、地区差异明显等特点,这些特征决定了中国地震的严重性和广泛性。地震灾害作为自然灾害的一个灾种,是自然灾害中造成损失最为严重的灾种。地震灾害发生造成人员伤亡较大,直接经济损失严重,产生严重的社会影响。面对地震灾害给国家和人民生命财产带来巨大损失,应用地震灾害风险区划理论方法,合理评价地震灾害对生命财产的影响尺度,开展抗震救灾工作是十必要且紧迫的。本文在查阅大量资料的基础上,简要介绍青藏高原区域构造特征、青藏铁路区域地貌单元、青藏铁路沿线活动断裂、青藏铁路沿线区域地震构造带,分析青藏铁路沿线区域地震活动特征和地震灾害的地震危险性与承险体脆弱性,对青藏铁路地震灾害进行风险区划。(1)青藏铁路活动断裂运动速度与地震地震级之间存在显著的正相关关系,基本符合断层运动速度-震级的统计分布规律,活动断裂运动速度α≥0.40mm/a的活动构造区可能孕育Ms≥6～7级左右地震,α≥0.70mm/a的活动构造区可能孕育8级左右强烈地震。青藏铁路横穿青藏高原地震活动区,沿线发育多条地震构造带,地震构造带与活动断裂带的交叉复合,存在大陆动力学关系。活动断裂带受地震构造带显著控制,尤其是不同方向断裂带的交叉复合部位,控制着青藏高原强震分布和地震破裂空间产状。(2)青藏铁路沿线区域地震震级与发生频次具有统计相关关系。地震震级能够良好地定量刻划地震活动强度与现今构造活动性,也是反映地壳稳定程度重要参数。青藏铁路地震震级与频次呈现关系方程式为:lgN=5.89-0.72m(m为震级档,N为震级档频次),即随着地震震级增大而发生频次减小。(3)青藏铁路地震灾害风险区划的主要影响因子为:地震发震强度、地震发震概率、承险体暴露度、承险体敏感度。根据地震灾害风险区划的要求,用定量数值描述影响因子指标体系,对青藏铁路沿线地震灾害风险区划。由地震灾害风险区划结果,可以比较地震危险性的大小和承险体脆弱性的高低,为防震减灾规划部门进行地震灾害风险规划提供参考依据。更多还原

【Abstract】 China, one of the world’s strongest seismic activity country located in junction of Circum-Pacific and Mediterranean-Himalayan seismotectonic zone, belongs to an earthquake-prone areas. The earthquake has ever taken place in Chin was high frequency, widely distributed, high strength, light source and regional differences are significant and so on. These characteristics of earthquake determine the severity and breadth of distribution. Earthquake, as a natural disaster species, was the most serious kind of disasters. The casualties, serious economic losses and social impact caused by the earthquake given people deep impression. The reality, tremendous loss of lives and poverty, was necessary for the reasonable assessment of earthquake which uses application of risk zoning method.In paper, briefly introduce regional tectonic features, regional landscape units, active faults, seismotectonic zone of Qinghai-Tibet Railway, and analyze the Qinghai-Tibet Railway characteristics of seismic activity and seismic hazard and risk bearing physical vulnerability, these all assessments based on large amount of data. On this basis, using ArcGIS to space the regional characteristics of the Qinghai-Tibet railway, landscape units, active faults, earthquake belt and Quantitative values for earthquake disaster risk zoning. Earthquake risk zoning, in the whole process, made some research and awareness as follows:(1) Active faults along the Qinghai-Tibet railway and seismic velocity are exist significant positive correlation between the magnitude and velocity. Earthquake tectonic belt and the active faults in different directions of cross-compound, have the relationship of continental dynamics. Seismotectonic zone control over the Qinghai-Tibet Plateau earthquake spatial distribution and earthquake rupture occurrence.(2) Magnitude, can be a good characterization of seismic activity intensity and the current tectonic activity, is also reflected the stability of the crust. Earthquake magnitude and frequency of statistically correlated: with the increase of magnitude, the frequency decrease occurred.(3) The main factor affecting the earthquake of Qinghai-Tibet Railway; earthquake intensity, earthquake probabilities, bearing body exposed to dangerous degrees, the bearing body of vulnerability risk. Risking based on zoning requirements, quantitative numerical description of factors and earthquake risk zoning. The results, from the earthquake disaster risk zoning, can catalogue into different classes by the compare of size of seismic risk and commitment of the vulnerability.Therefore, the earthquake disaster reduction of earthquake disaster can be offered directly for risk planning authorities.更多还原