Study on evaluation of cities' ability reducing earthquake disasters

Cities ability reducing earthquake disasters is a complex system involving numerous factors, moreover the re-search on evaluating cities ability reducing earthquake disasters relates to multi-subject, such as earthquake sci-ence, social science, economical science and so on. In this paper, firstly, the conception of cities ability reducing earthquake disasters is presented, and the ability could be evaluated with three basic elements the possible seis-mic casualty and economic loss during the future earthquakes that are likely to occur in the city and its surround-ings and time required for recovery after earthquake; based upon these three basic elements, a framework, which consists of six main components, for evaluating citys ability reducing earthquake disasters is proposed; then the statistical relations between the index system and the ratio of seismic casualty, the ratio of economic loss and re-covery time are gained utilizing the cities prediction results of earthquake disasters which were made during the ninth five-year plan; at last, the method defining the comprehensive index of cities ability reducing earthquake disasters is presented. Thus the relatively comprehensive theory frame is set up. The frame can evaluate cities ability reducing earthquake disasters absolutely and quantitatively and consequently instruct the decision-making on reducing cities earthquake disasters loss.

Security of earthquake disaster reduction system

No matter whether a system is operated manually or automatically controlled by computer, the system’s vulnerability always exists. Earthquake Disaster Reduction System (EDRS) belongs to the category of information system. According to the features of security for EDRS, the steps and the methods on how to build the EDRS security were analyzed. The EDRS security features, security strategies and security measures were also given through a distributed EDRS skeleton that has been applied. Because there was still no appointed and authoritative agency or organization to certify and test EDRS security in China, a national information technology security certification center was introduced and suggested for the certification of the EDRS security. Finally, several discussions and tendencies for the EDRS development were presented.

Reduction of earthquake disasters

The article summarizes the researches on mitigating earthquake disasters of the past four years in China. The study of earthquake disasters quantification shows that the losses increase remarkably when population concentrates in urban area and social wealth increase. The article also summarizes some new trends of studying earthquake disas-ters mitigation, which are from seismic hazard to seismic risk, from engineering disaster to social disaster and introduces the community-centered approach.

Redevelopment of Daqing Oil Field distributed earthquake disaster reduction system skeleton

Through investigation on the international development trend of earthquake disaster reduction system(EDRS)researches,a well finished Daqing Oilfield EDRS is introduced.Based on the PC System,redevelopment of the EDRS skeleton is well discussed,including the technical skeleton,function composition,structures of software and hardware,redevelopment languages,database,and remote linking and calling of analysis modules.Meanwhile,it is pointed out that extending and utilizing the function of remote sensing information on the basis of the current distributed EDRS skeleton will become another study direction of EDRS.

Performance of the Yangbi M_(S)6.4 earthquake disaster in different geomorphic units in Yunnan

An M_(S)6.4 earthquake occurred in Yangbi,Yunnan province,on May 21,2021.According to related investigations,the macro-epicenter of the earthquake is 6 km northwest of Yangbi County,and the seismogenic structure is the NW-trending Weixi-Qiaohou fault.The earthquake area is located in the hinterland of the Hengduan Mountains in the northwest of Yunnan Province,a region dominated by high and medium-high mountains,with deep canyons and tectonic basins in between.Various geomorphic features are derived from drastic topographic changes and huge geological differences in the earthquake area.There are a variety of buildings in the earthquake-affected zone,including civil and brick-wood structures ones with weak seismic performance,as well as brick-concrete and frame ones with better seismic performance.This paper summarizes and analyzes different characteristics of the earthquake in different geomorphic units through field investigations of different buildings and geological disasters in the affected area.The results show that under the same earthquake intensity,the damage to most buildings(located in slope areas or rooted in weak strata)is amplified by the earthquake.The earthquake has exerted an obvious propagation effect along the direction of the seismogenic structure.Moreover,local ground fissures will aggravate the damage to the buildings even without surface dislocation.Thus,we suggest that attention should be paid to the ground fissures caused by the slope effect.The fissure areas may also be the disaster spot of collapses and landslides in case of a high-magnitude earthquake.

The housing loss assessment of rural villages caused by earthquake disaster in Yunnan Province

Based on the assessment report of destructive housings caused by more than 20 earthquakes occurred in Yunnan Province in 1990~2004, the vulnerability models of 4 types housings of rural residents in Yunnan Province are setup. The scenario earthquake disaster loss model is used to simulate the housing loss if the historical earthquakes that occurred since A.D. 886 in Yunnan Province reoccur in 2002. The analyses show the simulation deviation of the usual earthquakes is less than 30% and the method is of high practicality. Meanwhile, the simulation result of 398 historical earthquakes in Yunnan Province shows that the annual economic loss caused by the earthquakes is about RMB 410 million Yuan that accounts for 0.18% of GDP of Yunnan Province for the year. Because the per capita living area and the price of the housing increases year by year, if the historical destructive earthquake reoc- curs today, the loss of Yunnan Province will be greater than in those years.

Method study of classification and gradation of earthquake disasters

Based on data of earthquake disaster events during 1954-2005 in the Chinese mainland, the classification and gradation of earthquake disasters have been studied by multivariate statistical analysis. Three fundamental structures of earthquake disasters have been found and an FAPE （factor analysis-principal component-equamax rotation） classification model and an HCWS （hierarchical cluster-ward method-seuclid） gradation model have been constructed. Earthquake disasters are divided into eight classes and five grades respectively in the models, which give a reasonable explanation to the phenomenon of earthquake disasters.

Safety Evaluation Method of Evacuation Routes in Areas in Case of Earthquake Disasters Using Ant Optimization Algorithm and Geographic Information Systems

The present study aims to propose the method for the quantitative evaluation of safety concerning evacuation routes in case of earthquake disasters in urban areas using ACO （Ant Colony Optimization） algorithm and GIS （Geographic Information Systems）. Regarding the safety evaluation method, firstly, the similarity in safety was focused on while taking into consideration road blockage probability, and after classifying roads by means of the hierarchical cluster analysis, the congestion rates of evacuation routes using ACO simulations were estimated. Based on these results, the multiple evacuation routes extracted were visualized on digital maps by means of GIS, and its safety was evaluated. Furthermore, the selection of safe evacuation routes between evacuation sites, for cases when the possibility of large-scale evacuation after an earthquake disaster is high, is made possible. As the safety evaluation method is based on public information, by obtaining the same geographic information as the present study, it is effective in other areas regardless of whether the information is of the past and future. Therefore, in addition to spatial reproducibility, the safety evaluation method also has high temporal reproducibility. Because safety evaluations are conducted on evacuation routes based on quantified data, highly safe evacuation routes that are selected have been quantitatively evaluated, and thus serve as an effective indicator when selecting evacuation routes.

Research on the Regional Ecological Environment Evaluation and Application under the Influence of the Severe Earthquake Disaster

To conduct the ecological restoration and reconstruction of disaster areas after the severe earthquake, such as Wenchuan Earthquake and Lushan Earthquake, this article uses region al ecological environment evaluation and ecological footprint to construct a quantitative analysis model on the basis of ecololgical environment indexes in Mianzhu City. Through this model, resource status of the regional environment in Mianzhu is analyzed, as well as the ecological capacity and the ecological security. Based on the evaluation and analysis, this paper provides multi-path development strategies of ecological restoration and sustainable development of human settlements after the earthquake.

The Characteristics of Earthquake Disasters and Countermeasures for Their Mitigation in Metropolitans

Metropolitans are a result of fast economic development in China. Many metropolitans have emerged in the eastern part of China. Earthquake disasters in metropolitans are more complicated and serious than those in a smaller city, and the impact of earthquake disaster on the economy and society is large. The characteristics of earthquake disasters and countermeasures to protect against and mitigate disaster in the metropolitan, as well as some key research fields in the earthquake disaster protection and mitigation, are discussed.

Earthquake Disaster and Seismic Activity in China Since 1949

An outline is given in the present paper of the general situation of earthquake disasters and their temporal,spatial,and magnitude distributions in China since 1949,based on recently published Chinese disaster data.A comparison was made between the earthquake disasters and seismic activities in China during this period.The results show that 477 disaster-causing earthquakes have occurred during this period,resulting in a death toll of 278,000 persons and the collapse of 11,000,000 rooms in residence houses.The total direct economic losses exceeded 42 billion Yuan(Chinese currency,the same below).A comparison of earthquake disasters in various regions(between East and West China,between various provinces,etc.)has shown that both correlations and significant differences exist between the spatial distributions of earthquake disasters and seismic activities in China.For example,seismic activity shows a feature of being "stronger in the West than in the East," whereas the earthquake disasters are stronger

Remote Sensing Technology and Applications for Earthquake Disasters

Disaster warning,disaster estimation and relief depend more and more on the application of space remote sensing technologies,such as those used for optic-camera,hyperspectrum,infrared,SAR,seismo-electromagnet and gravitation measurement.On May 12,2008,a magnitude of 8.

Earthquake Disaster Risk Reduction in Iran:Lessons and "Lessons Learned" from Three Large Earthquake Disasters——Tabas 1978,Rudbar 1990,and Bam 2003

This article addresses three large earthquake disasters in Iran: Tabas in 1978, Rudbar in 1990, and Bam in 2003. Lessons and 'Lessons Learned' from these three earthquake disasters were investigated together with their contributions over time towards earthquake disaster risk reduction in Iran. Many lessons from 1978 Tabas, 1990 Rudbar, and 2003 Bam did not become 'Lessons Learned' and they were identified again within the dramatic context of other earthquake disasters in various places of Iran. Both lessons and 'Lessons Learned' from Tabas, Rudbar, Bam,and other earthquake disasters in Iran require a sustainable long-term framework—an earthquake culture.

Preliminary report of the September 5,2022 M_(S) 6.8 Luding earthquake,Sichuan,China

The 2022 M_(S)6.8 Luding earthquake is the strongest earthquake in Sichuan Province, Western China, since the 2017 M_(S)7.0 Jiuzhaigou earthquake. It occurred on the Moxi fault in the southeastern segment of the Xianshuihe fault, a tectonically active and mountainous region with severe secondary earthquake disasters. To better understand the seismogenic mechanism and provide scientific support for future hazard mitigation, we summarize the preliminary results of the Luding earthquake, including seismotectonic background, seismicity and mainshock source characteristics and aftershock properties, and direct and secondary damage associated with the mainshock.The peak ground displacements in the NS and EW directions observed by the nearest GNSS station SCCM are ~35 mm and ~55 mm, respectively, resulting in the maximum coseismic dislocation of 20 mm along the NWW direction, which is consistent with the sinistral slip on the Xianshuihe fault. Back-projection of teleseismic P waves suggest that the mainshock rupture propagated toward south-southeast. The seismic intensity of the mainshock estimated from the back-projection results indicates a Mercalli scale of Ⅷ or above near the ruptured area,consistent with the results from instrumental measurements and field surveys. Numerous aftershocks were reported, with the largest being M_(S)4.5. Aftershock locations(up to September 18, 2022) exhibit 3 clusters spanning an area of 100 km long and 30 km wide. The magnitude and rate of aftershocks decreased as expected, and the depths became shallower with time. The mainshock and two aftershocks show left-lateral strike-slip focal mechanisms. For the aftershock sequence, the b-value from the Gutenberg-Richter frequency-magnitude relationship, h-value, and p-value for Omori’s law for aftershock decay are 0.81, 1.4, and 1.21, respectively, indicating that this is a typical mainshock-aftershock sequence. The low b-value implies high background stress in the hypocenter region. Analysis from remote sensing satellite images and UAV data shows that the distribution of earthquake-triggered landslides was consistent with the aftershock area. Numerous small-size landslides with limited volumes were revealed, which damaged or buried the roads and severely hindered the rescue process.

Ideas of establishing the information system for emergence decisions on the protection against earthquakes and disaster reduction in cities (application of GIS)

ith urban reformation and opening becoming deeper,the work of protection against earthquake and disaster reduction would be more important.In this paper,some ideas are suggested about establishing the information system for emergency decisions on protection against earthquake and disaster reduction in cities .The information system mainly includes a subsystem for rapid evaluation of damage loss from earthquake (which includes input of seismic information,distribution of earthquake intensity,evaluation of seismic fragility on all social factors and etc.) and a subsystem for the decisive information of seismic emergency(which mainly includes project of disaster relief,project of personnel evacuation,dangerous degree warning for the dangerous articlesstoring places and protection measures against them,assistant decision on fire due to earthquake,location of headquarter for providing disaster relief,and etc.). It is thought that the data investigation and collection about all kinds of buildings(including lifeline engineering)are the most important and difficult work as establishing this system.

Information system for emergence decision on the protection against earthquake and disaster reduction in Shanghai City──Application of GIS

For meeting the need of rapid development of economy in Shanghai and the protection against earthquake and disaster reduction in the mega city, it is necessary to build a information system for emergence decision on the protection against earthquake and disaster reduction in the city. In this paper, GIS is applied to 'the information system for emergence decision on the protection against earthquake and disaster reduction in Shanghai City (Baoshan experiment region)'. We introduce to the structure and effect of each functional module in this information system. This information system consists of 7 functional modules:background information of seismology and geology, subsystem for rapid evaluation of damage loss from earthquake, subsystem for the decisive information on earthquake emergence, information query, maintenance and management of system, help, quit. The key parts of this information system are the subsystem for rapid evaluation of damage loss from earthquake and the subsystem for the decisive information on earthquake emergence. Also, this paper introduces to the application of technology of color infra-red aerial photograph remote sensing to this information system.

Seismic characteristics near the epicenter of the 1303 Hongtong M=8 earthquake, Shanxi Province and its implication

In this paper, we calculated the seismic pattern of instrumental recorded small and moderate earthquakes near the epicenter of the 1303 Hongtong M=8 earthquake, Shanxi Province. According to the spatial distribution of small and moderate earthquakes, 6 seismic dense zones are delineated. Temporal distribution of ML2 earthquakes since 1970 in each seismic dense zone has been analyzed. Based on temporal distribution characteristics and historical earthquake activity, three types of seismicities are proposed. The relationship between seismic types and crustal medium is analyzed. The mechanism of three types is discussed. Finity of strong earthquake recurrence is pro-posed. Seismic hazard in mid-long term and diversity of earthquake disaster in Shanxi seismic belt are discussed.

Earthquake loss estimation by using Gross Domestic Product and population data

In the traditional method of earthquake loss estimation, all the social wealthes are classified according to their structural type and occupational use. Inventory data is collected and the total loss is estimated from each facility class separately. For many regions of the world, however, the vast amount of data required by this method is difficult or impossible to obtain. The traditional method is also unable to estimate quickly the loss from an unexpected disaster earthquake. It is difficult to give the necessary risk information to help the government to rescue and relief the earthquake disaster. This paper proposes a simple estimation method of earthquake loss based on macroscopic economical index of Gross Domestic Product (GDP) and population distribution data. A preliminary nonlinear relation among hazard loss, seismic intensity and social wealth was developed by means of some earthquake disaster records during 1980～1995. This method was applied to analyze several assumed earthquakes. The preliminary analysis results show that the new method is effective and reasonable for quick assessment of earthquake loss.

Annual Consultation on the Likelihood of Earthquakes in Continental China: Its Scientific and Practical Merits

Since the 1970s, Chinese seismologists have started to conduct the Annual Consultation on the Likelihood of Coming Earthquakes in the Next Year. This approach has unique scientific and practical merits either as an active response to the social needs in the situation that earthquake prediction research meets many difficulties, or as a real forward prediction test persistently conducted for 1/3 century. It is a pity that such an approach has not been well-known by international seismological community, and the scientific merits of such an endeavor is sometimes regrettably underestimated.

Analysis on Characteristics of the Hazards of the 2015 Pishan Ms 6.5 Earthquake in Xinjiang

The disaster area of the Pishan M_S6.5 earthquake in 2015 is located in the southern margin of the Tarim Basin,where the natural condition are harsh,and the economy is extremely backward.Moreover,because of a large number of residential housing with poor seismic performance in the disaster area,the damage and economic losses are serious.Since the most disaster area is located in the piedmont overflow,with poor site conditions such as shallow groundwater level and soil foundation,the magnifying effect of ground motion has a significant impact on the damage.In conclusion,we believe that investment in antiearthquake housing projects should be increased in post disaster reconstruction.Furthermore,for the north of the disaster area,with the dense population,poor conditions like soft soil foundation and poor engineering geological conditions,we recommend that in the future construction of anti-earthquake housing projects,more attention should be paid to strengthen the foundation treatment and precaution measures.