基于历史相似案例空间推演的地震伤亡人口评估方法研究

地震是对人类生存构成最大威胁的自然灾害之一,往往导致巨大的损失。本研究选取中国2000—2013年震级为4.0级以上且有人员伤亡的地震灾害统计数据作为历史案例,以基于历史案例的灾情加权综合评估模型（Assessment Method of Natural Disaster Based on Similarly Historical Cases,SHC）为基础,考虑历史案例与当前灾害的空间相关程度,获得改进的基于历史相似案例空间推演的地震伤亡人口评估（Assessment Method of Earthquake Casualties Based on Spatial Reasoning of Similarly Historical Cases,SRSHC）;并选取2010年青海玉树地震、2013年四川芦山地震及2014年云南鲁甸地震作为验证案例,进行精度验证。结果表明:① 对于3个验证案例,SRSHC模型的最佳评估精度均在95%以上,表明该方法在地震伤亡人口评估方面具有一定的可行性及适用性;② SRSHC模型相较于SHC模型,参评案例的个数少且精度更高,以2010年四川芦山地震为例,当参评案例个数为3个时,SRSHC模型评估结果达到最佳（97.92%）;而SHC模型参评案例个数需6个达到评估结果最佳（35.49%）,这表明历史案例与当前灾害发生地区的空间相关程度对评估结果有较大影响;③ 灾情评估的精度与参评案例的个数有关,当参评案例在2个以上时,模型评估的精度随着参评案例个数的增加呈平稳下降趋势;当参评案例的个数为3~4个时,SRSHC模型的评估精度最佳。基于历史案例的灾情评估方法成本低、效率高、时效性强,且方法简单、约束条件较少、容易实现, 在灾情评估方面具有一定的实用价值。     

Impact of the Wenchuan Earthquake on tourism in Sichuan, China

An intensive earthquake, the Wenchuan Earthquake of 8.0 on the Richter scale, struck western Sichuan, China on May 12, 2008. The earthquake has tremendously affected all industries in the quake-hit areas, with no exception ：of the local tourism. The study of the effect of the earthquake on tourism enriches the theory of tourism, and more importantly, it well serves as the foundation for policy making. The objective of this study is to outline for readers the empirical findings on the various ways that the earthquake affected the operations and viability of tourism in the quake-hit areas. This paper is mainly divided into 3 parts. The first part is to discuss the importance of tourism in the quake-hit areas. The second is to analyze the influencing factors of tourism. The third is to assess the impact of the earthquake on tourism in Sichuan in different seasons.     

The impact of catastrophic natural disaster on land-use changes of Qingping town and the selection of suitable land for settlement construction

A Ms 8.0 large earthquake occurred in Sichuan,China on May 12,2008(hereafter called 5.12 Earthquake),and then a large debris flow happened in the quake-hit Qingping Township of Mianzhu county on August 13,2008(hereafter called 8.13 Debris Flow).The influence of two disasters on the changes in land use were analyzed by using highresolution aerial photos and satellite remote sensing images taken before and after the 5.12 Earthquake and 8.13 Debris Flow,the selection of suitable construction land were studied by learning experiences and lessons from the selection of resettlement areas and through field surveys and with land use transfer model and analytical model in combination with RS and GIS.The results showed that the influence of the 5.12 Earthquake on ecological environment was far greater than that of the 8.13 Debris Flow;there were more salient conflicts between population and land after the earthquake.Sites for post-disaster reconstruction should not be in disaster-prone areas or in gully-facing areas.Suitable land for settlement construction in I-1~I-5 low-hazard zones is optimal settlement areas for post-disaster reconstruction.     

Forecast method of multimode system for debris flow risk assessment in Qingping Town, Sichuan Province, China

The Wenchuan Earthquake of May 12,2008 triggered large numbers of geo-hazards.The heavy rain on 13 August 2010 triggered debris flows with total volume of more than 6 million cubic meters and the debris flows destroyed 500 houses and infrastructure built after the Wenchuan Earthquake.The study area Qingping Town was located in the northwestern part of the Sichuan Basin of China,which needs the second reconstructions and the critical evaluation of debris flow.This study takes basin as the study unit and defines collapse,landslide and debris flow hazard as a geo-hazard system.A multimode system composed of principal series system and secondary parallel system were established to evaluate the hazard grade of debris flow in 138 drainage basins of Qingping Town.The evaluation result shows that 30.43% of study basins(42 basins) and 24.58% of study area,are in extremely high or high hazard grades,and both percentage of basin quantity and percentage of area in different hazard grades decrease with the increase of hazard grade.According to the geo-hazard data from the interpretation of unmanned plane image with a 0.5-m resolution and field investigation after the Wenchuan Earthquake and 8.13 Big Debris Flow,the ratio of landslides and collapses increased after the Wenchuan Earthquake and the ratios of extremely high or high hazard grades were more than moderate or low hazard grades obviously.23 geo-hazards after8.13 Big Debris Flow in Qingping town region all occurred in basins with extremely high or high hazard grades,and 9 debris flows were in basins with extremely high hazard grade.The model of multimode system for critical evaluation could forecast not only the collapse and landslide but also the debris flow precisely when the basin was taken as the study unit.     

Influences of the Wenchuan Earthquake on sediment supply of debris flows

The 5.12 Wenchuan Earthquake and the subsequent rainstorms induced a large number of landslides, which later were transformed into debris flows. To evaluate the effect of the earthquake on the sediment supply of debris flows, eight debris flow basins near Beichuan City, Sichuan Province, China were chosen as the study area. The area variations of the debris flow source after the Wenchuan Earthquake and the subsequent rainstorm are analyzed and discussed in this paper. Interpretations of aerial photographs (after the 5.12 Wenchuan Earthquake) and SPOT5 images (after the rainstorm event of September 24, 2008) as well as field investigations were compared to identify the transformation of landslide surface in the study area, indicating that the landslide area in the eight debris flow basins significantly increased. The loose sediment area on the channel bed increased after the rainstorm event. In order to estimate the relationship of the landslide area with the rainfall intensity in different return periods, a model proposed by Uchihugi was adopted. Results show that new landslide area induced by heavy rainfall with 50-year and 100-year return period will be 0.87 km2 and 1.67 km2, respectively. The study results show the Wenchuan earthquake had particular influences on subsequent rainfall-induced debris flow occurrence.     

澜沧-耿马Ms7.6级地震前兆综合加权信息量的变化

在地震综合信息量的基础上,改进了地震前兆异常的出现概率的计算方法,得到地震前兆综合加权信息量.利用"地震预报专家系统"的思想对每一异常事件进行综合评估.考虑到异常的可靠性、有效性、显著性及相互关联性,给予不同的权重,以每一异常事件的最可能发震时间来估算异常出现的概率,计算了澜沧-耿马地震的地震前兆综合加权信息量,并对这种信息量变化的特点进行了分析.     

地震之争——写在"5·12"汶川特大地震一周年之际

"5·12"汶川特大地震过去一年了,然而关于地震的争议远没有停止.中国是否进入强震频发期?地震预报为什么这么难?水库是否诱发了地震……地震带来的一系列问题让地质专家不断研究和思索.     

Rapid susceptibility mapping of co-seismic landslides triggered by the 2013 Lushan Earthquake using the regression model developed for the 2008 Wenchuan Earthquake

The primary objective of landslide susceptibility mapping is the prediction of potential landslides in landslide-prone areas.The predictive power of a landslide susceptibility mapping model could be tested in an adjacent area of similar geoenvironmental conditions to find out the reliability.Both the 2008 Wenchuan Earthquake and the 2013 Lushan Earthquake occurred in the Longmen Mountain seismic zone,with similar topographical and geological conditions.The two earthquakes are both featured by thrust fault and similar seismic mechanism.This paper adopted the susceptibility mapping model of co-seismic landslides triggered by Wenchuan earthquake to predict the spatial distribution of landslides induced by Lushan earthquake.Six influencing parameters were taken into consideration: distance from the seismic fault,slope gradient,lithology,distance from drainage,elevation and Peak Ground Acceleration(PGA).The preliminary results suggested that the zones with high susceptibility of coseismic landslides were mainly distributed in the mountainous areas of Lushan,Baoxing and Tianquan counties.The co-seismic landslide susceptibility map was completed in two days after the quake and sent to the field investigators to provide guidance for rescue and relief work.The predictive power of the susceptibility map was validated by ROC curve analysis method using 2037 co-seismic landslides in the epicenter area.The AUC value of 0.710 indicated that the susceptibility model derived from Wenchuan Earthquake landslides showed good accuracy in predicting the landslides triggered by Lushan earthquake.     

三峡库首湖北秭归连续地震“6问”

正近日,"三峡库首第一县"湖北省秭归县接连发生4.3级和4.7级两次地震。两次地震震中距离三峡大坝仅23公里,因此备受关注。3月31日下午,湖北省和宜昌市地震局召开媒体见面会,对社会普遍关心的地震是否与三峡蓄水有关,是否影响大坝安全,是否还有较大地震等等问题,中国地震局地震研究所水库诱发地震研究室主任王秋良等专家进行了现场解答。按照目前2次地震的调查情况,3月27日发生的4.3级地震,震中区有5度的震害,3月30日发生的4.7级地震,震中区达到6度震害。问题一:两次地震产生的危害有多大?     

基于ArcGIS的地震活断层多源数据组织与管理研究

"中国地震活动断层探测技术系统"获取的全国20多个重点城市多源地震探测数据,旨在满足城市地震抗震设防的空间数据基础建设以及城市发展规划、土地利用、重大工程选址应用的迫切需求,分析不同来源的地震探测数据特征,建立中国活动断层探测与地震危险性评价数据库的概念模型。在此概念模型上,结合ArcGIS的GeoDatabase模型给出了城市活动断层探测数据库具体逻辑模型,并按照地震系统确定的活动断层信息管理系统与基础数据库统一的建库标准和数据规范,实现多种活断层探测数据的统一整理和装载入库,完成了全国多个重点城市的活断层探测多源数据库建设,为"中国地震活动断层探测技术系统"各分工程的实施提供了数据保障和数据服务。     

清江隔河岩水库诱发地震的条件与地震活动特征

分析了清江隔河岩水库区诱发地震的形成条件、地震时空分布特征以及库水位与地震活动的相关性 ,结果表明 :该水库的地震活动类型属典型的震群型水库地震 ,其成因主要为岩溶陷落。     

基于格网的汶川地震场地灾害监测分析

本文利用格网技术(Fishnet),对龙门山地区"5.12"大地震震后的多期次遥感影像数据及基础地理信息数据进行评价、整合并实现了动态管理,在此基础上得到覆盖整个龙门山构造带的、能够反映不同地物信息的影像群.汶川地震造成了大量山体崩塌、滑坡、泥石流等地震场地灾害,这些灾害体表现为成群、成带分布的特征,并且单一的小灾害体...     

1993年咸宁地震群震害损失及发震成因探讨

1993年7~8月,湖北省咸宁地区发生了一系列ML≤4.1的地震。从地震系列、地表破坏状况和地震宏观等烈度线展布特征出发,深入研究了地震与地质构造及地下水动态变化的关系,得出结论地震群可能为抽取地下水引起的构造变动而诱发。     

Mechanism and geo-mechanics models of landslides triggered by 5.12 Wenchuan Earthquake

Due to the extremely high magnitude, long duration, and the complicated geo-environment in the disaster area, the great 5.12 Wenchuan Earthquake not only produced a huge number of landslides and rockfalls, but also involved complicated dynamic processes. These processes are quite different from the characteristics of landslides and rockfalls under general gravitational force, and presently human knowledge is very poor in this field. In order to describe the special dynamic processes, some terms such as shattering-cracking, shattering-sliding, shattering-falls and ejection are defined in this paper. Combined with slope structures, a mechanism classification system of strong earthquake-triggered landslide and rockfall is suggested, which is divided into 5 categories and 14 types. This paper also analyzes the basic characteristics, dynamic processes and geo-mechanics conceptual models of some typologies, especial the type of shattering-sliding for most large-scales landsides. This paper initially reveals the formation mechanism, geo-mechanics models and dynamic features of landslides and rockfalls triggered by the great Wenchuan Earthquake.     

《地震大地测量学》专著即将面世

<正>1966年邢台大地震后,防震减灾成为我国的国家任务,现代大地测量学应用于世界科学难题——地震预测探索;与地震学、构造地质学、岩石力学和复杂动力系统理论相交融,开拓了现今大陆地壳运动与变形动力学(10~(-2)s~10~2 a)研究新领域,逐步成长为一门地学前沿交叉新兴学科——地震大地测量学(Earthquake Geodesy)。50年后,由武汉大学出版社出版的《地震大地测量学》专著即将面世。     

Study on the Rainfall and Aftershock Threshold for Debris Flow of Post-earthquake

Due to the special condition of provenance and disaster environment after 5·12 Earthquake, the probability and conditions of the occurrence of gully debris flow change greatly after the event, which make it difficult to prevent disaster effectively. In this study the hydrological model of ground water table in loose sediment is established. According to infinite slope theory, the safety factor of deposits is defined as the ratio of resistance force to driving force. The starting condition of post-earthquake...     

2008年汶川MS8.0地震与2017年九寨沟MS7.0地震成因关系探讨

利用2008年汶川地震破裂模型及2017年九寨沟地震接收断层参数和断层面有效摩擦系数等不同模型参数,计算2008年汶川地震造成的库仑应力变化。结果显示,在考虑不同模型参数条件下,2017年九寨沟地震震源处的库仑应力增量（同震及震后）约为3~7 kPa,尚未达到地震触发阈值10 kPa。综合分析认为,2008年汶川地震对2017年九寨沟地震有一定的触发作用,但作用十分有限,九寨沟地震的发生主要受控于区域构造活动及地壳流变结构。分析不同参数对计算结果的影响发现,不同破裂模型的选取对2018年汶川地震计算结果的影响最大,这可能是导致前人研究结论产生差异的原因之一。     

四川汶川“5.12”地震滑坡堰塞湖遥感监测分析

运用可见光、雷达和航片等不同空间分辨率的多源遥感数据,对四川汶川"5.12"地震灾区因地震诱发形成的大型堰塞湖进行了遥感监测,对堰塞湖发生的地点、数量以及空间分布规律进行了讨论。重点对唐家山堰塞湖进行了动态监测,提取了其堰塞湖回水长度、水面面积与水量等信息,并对这一结果进行了详细分析,为地震滑坡堰塞湖科学处置与减灾决策提供了科学依据。     

贵州三板溪水库诱发地震活动特征分析

研究了贵州省三板溪水库蓄水前后的地震活动特征与地震成因类型, 认为三板溪水库蓄水后出现的地震成因类型可划分为水库诱发构造型和地壳表层卸荷型。     

Study on the rainfall and aftershock threshold for debris flow of post-earthquake

Due to the special condition of provenance and disaster environment after "5·12" Earthquake, the probability and conditions of the occurrence of gully debris flow change greatly after the event, which make it difficult to prevent disaster effectively. In this study the hydrological model of ground water table in loose sediment is established. According to infinite slope theory, the safety factor of deposits is defined as the ratio of resistance force to driving force. The starting condition of post-earthquake gully debris flow is clearly studied by analyzing the effects of rainfall intensity, seismic strength, slope gradient and mechanical properties on the balance of accumulation body. Then the formulas of rainfall and aftershock threshold for starting of gully debris flow are proposed, and an example is given to illustrate the effect of rainfall, aftershocks and their coupling action on a debris flow. The result shows the critical rainfall intensity decreases as the lateral seismic acceleration and channel gradient increases, while the critical intensity linearly increases as the friction angle increases.