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Nearly half of coal mine disasters in China have been found to occur in clusters or to be accompanied by earthquakes nearby, in which all the disaster types are involved. Stress disturbances seem to exist among mining areas and to be responsible for the observed clustering. The earthquakes accompanied by coal mine disasters may be the vital geophysical evidence for tectonic stress disturbances around mining areas. This paper analyzes all the possible causative factors to demonstrate the authenticity and reliability of the observed phenomena. A quantitative study was performed on the degree of clustering, and space–time distribution curves are obtained. Under the threshold of 100 km, 47% of disasters are involved in cluster series and 372 coal mine disasters accompanied by earthquakes. The majority cluster series lasting for 1–2 days correspond well earthquakes nearby, which are speculated to be related to local stress disturbance. While the minority lasting longer than 4 days correspond well with fatal earthquakes, which are speculated to be related to regional stress disturbance. The cluster series possess multiple properties, such as the area, the distance, the related disasters, etc., and compared with the energy and the magnitude of earthquakes, good correspondences are acquired. It indicates that the cluster series of coal mine disasters and earthquakes are linked with fatal earthquakes and may serve as footprints of regional stress disturbance. Speculations relating to the geological model are made, and five disaster-causing models are examined. To earthquake research and disaster prevention, widely scientific significance is suggested. [ABSTRACT FROM AUTHOR]

China is one of the countries most affected by earthquakes. Improving public cognition and response to earthquake disaster (EDCR) is an effective means to reduce seismic risk and losses. The 2013 Lushan earthquake area was also stricken by the 2008 Wenchuan earthquake. Most of the residents in this area have been affected by both earthquakes, which provides a rare opportunity to gain insight into the interaction between public's EDCR and their earthquake disaster experience. Using a questionnaire survey on over 200 local residents selected by stratified sampling method, this paper investigates the public's cognition and response capability with regard to earthquake disaster in the 2013 Mw6.6 Lushan earthquake area, Sichuan Province, China, with a particular emphasis on exploration on the relationship between people's earthquake disaster experience and their disaster cognition and response behaviors. The results show that the overall EDCR level of local residents is moderate—their average cognition and response score for earthquake disaster is only 0.60. The number of earthquakes experienced, education, and family income level are the three most important factors that significantly impact an individual's overall EDCR capability. Those who have experienced more earthquakes better adapt to the impacts of disaster. Especially, the experience learned from the 2008 Mw7.9 Wenchuan earthquake played a positive role in the cognition and response of the public to the 2013 Lushan earthquake. In addition, people with higher education could master more knowledge of earthquake disaster and better control their emotions. Similarly, respondents with a higher family income had more resources and ways to engage in more reasonable response behaviors to manage disaster effects. Based on these findings, it is suggested that local policy-makers implement targeted earthquake disaster education and knowledge dissemination strategies, especially develop and expand various experiential learning modes (e.g., emergency exercise/drilling, situational learning, virtual reality, scenario approach, safety/disaster experience center, participatory activities) for the local public and beyond to more effectively strengthen their cognition of disaster and response capability. [ABSTRACT FROM AUTHOR]

An Ms 6.5 earthquake shocked the Ludian County, Yunnan Province, China, on 3 August 2014 and triggered the Hongshiyan landslide dam. The dam, with a height of 83 m and a lake capacity of 260 × 10 m, threatened more than 10,000 people. A unique feature of this landslide dam was that it formed between a man-made dam and a hydropower plant. An existing drainage tunnel connecting the lake and the hydropower plant became a natural drainage conduit for the landslide dam, which played an important role in the mitigation of the landslide dam risks. This paper reports a quantitative risk assessment for the Hongshiyan landslide dam considering both engineering and non-engineering risk mitigation measures. The risk assessment is divided into three stages according to the implementation of two engineering measures: construction of a diversion channel and excavation of a branch drainage tunnel. The dam breaching hydrographs, flood zones, population at risk, and likely fatalities in each of the three stages are analysed. The optimum evacuation strategy in each stage is also studied based on the principle of minimum total consequence. It is found that the diversion channel decreases the dam breaching peak discharge and the associated risks significantly. The branch drainage tunnel prevent the landslide dam from overtopping failure in non-flooded period; however, the landslide dam may fail by overtopping in a future flood if the inflow rate is larger than the outflow rate through the drainage tunnels, resulting in serious losses of lives and properties. The dam breaching risks in all the three stages could be largely reduced by the optimal evacuation decision, which shows that timely evacuation is vital to save life and properties. The study provides a scientific basis for decision making in landslide dam risk management. [ABSTRACT FROM AUTHOR]

The objective of this paper is to evaluate seismic-led point source and non-point source water pollution, under the seismic hazard of 10 % probability of exceedance in 50 years, and with the minimum value of the water quality standard in Sichuan, China. The soil conservation service curve number method of calculating the runoff depth in the single rainfall event combined with the seismic damage index were applied to estimate the potential degree of non-point source water pollution. To estimate the potential impact of point source water pollution, a comprehensive water pollution evaluation framework is constructed using a combination of Water Quality Index and Seismic Damage Index methods. The four key findings of this paper are: (1) The water catchment that has the highest factory concentration does not have the highest risk of non-point source water contamination induced by the outbreak of potential earthquake. (2) The water catchment that has the highest numbers of cumulative water pollutants types are typically located in the south western parts of Sichuan where the main river basins in the regions flow through. (3) The most common pollutants in sample factories studied is COD and NH-N which are found in all catchments. The least common pollutant is pathogen-found present in W1 catchment which has the best rating in the water quality index. (4) Using water quality index as a standardization parameter, parallel comparisons is made among the 16 water catchments. Only catchment W1 reaches level II water quality status which has the rating of moderately polluted in events of earthquake induced water contamination. All other areas suffer from severe water contamination with multiple pollution sources. The results from the data model are significant to urban planning commissions and businesses to strategically choose their factory locations in order to minimize potential hazardous impact during the outbreak of earthquake. [ABSTRACT FROM AUTHOR]

Most seismic casualty estimations are based on the vulnerability of various categories of structure and facilities in the region concerned. These approaches require detailed inventory database of the structures and facilities in the region. In China, however, the data is not always available, especially for some underdeveloped regions. This motivates the development of empirical models that use historical casualty data for earthquakes and provide a country- or region-specific earthquake death rate as a function of ground shake. However, diminishing divergences in fitting method and obtaining higher accuracy are still a great challenge. Building on the findings of previous research, the present paper employs vulnerability curves to express the relation between seismic intensity and mortality. From data of the death rate by intensity, curves are established for the whole of China and western China. Some methodological improvements are also discussed. To validate the curves, data from four recent strong earthquakes occurred in western China are used, and the best curves for estimation are selected and compared with similar models. Results indicate that the established curves for western China give a better estimation for the four earthquakes and the logistic functions show higher accuracy. They can be used to clarify the magnitude of seismic deaths in western China when structure and facility data are unavailable. Uncertainties and the application of the models are also analyzed and discussed in the conclusion. [ABSTRACT FROM AUTHOR]

A high steep rock hill with two-side slopes near National Road 213 is used as a prototype in this paper. The full process from initial deformation to sliding of the slope during ground shaking is simulated by a new discrete element method-continuum-based discrete element method. Then, the seismic responses of a high steep rock hill with two-side slopes are researched from the base of time, frequency and joint time-frequency domain using Hilbert-Huang transform and Fourier Transform. The findings are: first, the stress concentration phenomenon occurs at the top of the sliding mass, and then some tension and shear failure points appear, which expand from the top toward the toe of the sliding mass along the structural plane. At the same time, the number of tension failure points gradually increases. Then the toe of the sliding mass fails, and shears out from its toe which results in the landslide. If the material parameters are under the same conditions, the landslide in the middle of the slope occurs before that at the foot of slope, and the starting time of landslide and the arrival time of the peak ground acceleration are synchronous or the former slightly lags behind the latter. The difference of distribution and dissipation of earthquake energy in the sliding body and sliding bed is the major influence factor to induce the landslide. When the accelerations are small, the instantaneous frequency of accelerations between sliding bed and sliding body is generally consistent, the energy transmittance coefficients of the sliding structural plane and the controlled frequency band of the energy all range in a limitation; with the increase of the seismic intensity, the instantaneous frequency and the energy transmittance coefficients gradually decrease, and then they are steady within the lower limitation. At the same time, the controlled frequency band also shifts gradually from high frequency band to the lower one. Based on the input seismic wave, the peak acceleration amplifies as the increase of elevation, regardless of the monitoring points on the steep slope, gentle slope side or inside of the slope. Generally speaking, amplification of the vertical peak acceleration is stronger than that of the horizontal peak acceleration, and amplification of the peak acceleration on a steep slope is stronger than that on a gentle slope, and that of inside of the slope is the weakest amplification. [ABSTRACT FROM AUTHOR]

On June 24, 2017, a catastrophic landslide (Xinmo landslide) occurred on the left bank of Songping river in Diexi town, Sichuan Province, China. Based on field investigations, this paper tries to reveal the cause and mechanism of the initiation and development of the Xinmo landslide. Xinmo landslide is located in the so called “Minshan block.” This tectonic block is very active and generates many earthquakes. Among them, the 1933 Diexi Ms 7.5 earthquake which had an indispensable effect on the occurrence of the Xinmo landslide, whose distance to the recent Xinmo landslide is only 8.7 km. The 1933 earthquake triggered the collapse of the Qianxin gully, which damaged the rock mass forming the source of the Xinmo landslide and creating a free prominent ridge. The later 1976 Songpan Ms 7.2 earthquake and the 2008 Wenchuan Ms 8.0 earthquake further damaged the integrity of the rock mass in the source area of the 2017 Xinmo landslide. The Xinmo landslide developed on a typical bedding dip slope with metasandstone intercalated with a few thin bedded slate layers. The slate intercalation gives the slope a very low shear strength in the dip direction and the long term rainfall may have softened the slip zone and the locked section. These two aspects have promoted the occurrence of Xinmo landslide. [ABSTRACT FROM AUTHOR]

Households vary in their ability to deal with disasters, and this may lead to different recovery results. Aiming to examine this differentiation, this paper studied the 2009 Yao'an earthquake in China. Surveys of 200 destroyed rural households were conducted in field investigations and follow-ups at 1 month, 1 year, and 1.5 years after the earthquake. The results showed a clear difference in recovery, the households observably being classified into five groups. These are the O group, which has different recovery time and economic cost from the other four; and the special group, comprising E T and E T (vulnerable during recovery); E T (strong during recovery); and E T (neither vulnerable nor strong). Logistic regression analysis revealed that differentiation in recovery patterns arose from the combined effect of demographic factors and external assistance provided to households. Lower income is the root cause of vulnerability in some households during the recovery process. However, other factors cause recovery differences between the two vulnerable groups, causing the economic recovery cost of the E T group to be lower, and the recovery time of the E T group to be longer. There was consensus that external assistance had an impact on all households. The more provided and the earlier it arrived, the lower the cost for recovery and the shorter the recovery time. This study shows that research on group differentiation of recovery is useful in understanding post-earthquake recovery processes and calls for taking group differentiation considerations into account in post-disaster recovery resource allocation practices. [ABSTRACT FROM AUTHOR]

Debris flows can be extremely destructive because they can increase in magnitude via progressive entrainment. In this paper, a total of 18 landslide-type debris flows and 268 channelized debris flows in Wenchuan earthquake and Taiwan region, as well as other regions were collected to analyze the entrainment rate of debris flows in each triggering condition. Results show that there is a power relationship between volume of initial triggered mass and final deposited debris for landslide type debris flow. The debris flows during 2008 and 2013 in Wenchuan earthquake-region have smaller entrainment rate than that from 2001 t0 2009 in Taiwan. The entrainment rate of debris flow events from 2001 to 2009 in Taiwan shows a decaying tendency as elapsed time. Comparison of the entrainment rate in the two earthquake-hit regions with other regions proves that entrainment rate has a close relation with major sediment availability and secondary rainstorm conditions. [ABSTRACT FROM AUTHOR]

Relief supply warehouses are material warehouses built to cope with natural disasters and guarantee the supply of life necessities. Great earthquakes (with Ms ≥ 7) are overwhelming natural disasters beyond human control. The efficiency in rescuing earthquake victims depends on if the construction preparations of large relief supply warehouses have fully assessed the influence weights of the factors of large earthquake disasters. We innovatively proposes a method for selecting ideal site of relief supply warehouses in terms of seismic evaluation and the quantification of site selection criteria. We assess disaster-affected areas and screen the transport mode of relief supplies based on seismic prediction and remote sensing recognition, quantify and classify the site selection criteria of relief supply warehouses in China, and finally determine the ideal site. Taking a seismically-active region as a study case, we identify seven major disaster-affected areas, estimate the largest safe flight range (255 km) of a helicopter in post-earthquake transport of relief supplies, and pre-selecte 37 candidate sites. We suggest that the spatial distances between candidate sites and essential transport hubs (such as airports, railway stations, and highway entrances/exits) and the construction planning of the city are crucial indicators for the ideal site selection. [ABSTRACT FROM AUTHOR]

Detailed and accurate historical earthquake disaster data are an important basis for understanding the characteristics of earthquake disaster losses and for conducting research on earthquake disaster prevention strategies and post-earthquake emergency rescue work. Due to different project scopes and discrepancies in data accuracy, the currently available databases may contain errors such as missing data or data with low accuracies. In this study, we developed the Mainland China Composite Earthquake causing Casualties Database (MCCEC-DAT), which contains 252 historical earthquake records that span from 1966 to 2021. The database contains earthquake attribute information (earthquake time, location, epicenter latitude and longitude, focal depth, epicentral intensity, etc.), loss information (number of deaths and injuries, building damage ratio, economic loss, cause of death, etc.), and socioeconomic data (population, population density, area of each zone of seismic intensity, mortality rate, etc.). This database also contains the lethality levels generated by this study. These levels are the result of the quantitative evaluation of the overall characteristic levels of the earthquake area. Furthermore, this metric permits the direct comparison of different spatial locations. Based on the results of the statistical analysis, this work shows that the distribution of historical earthquakes in mainland China has obvious spatial and temporal characteristics. Events are mainly distributed throughout the southwest region, and the magnitudes of those events are relatively diverse. The mortality rate is significantly correlated with the building damage ratio and the lethality level. The lethality level can not only facilitate an improved understanding of the comprehensive level of historical earthquake regions, but this metric also provides a quantitative foundation for the comparative analysis of earthquakes between different regions. Furthermore, the database can also provide a foundation for future research, such as research into assessing the loss from earthquake disasters. [ABSTRACT FROM AUTHOR]

Investigating the emissions of soil gas including radon, mercury and carbon dioxide (222Rn, Hg and CO2) from the solid earth to the atmosphere through active fault zones is of great significance for accession of atmospheric environment. In this study, the concentrations and fluxes of 222Rn, Hg and CO2 were measured at the main active fault zones at the western margin of the Ordos block, China. The concentrations of 222Rn, Hg and CO2 were in the range of 0–60.1 kBq m−3, 3–81 ng m−3 and 0.04–9.23%, respectively, while the fluxes of 222Rn, Hg and CO2 are in the range of 1.99–306.99 mBq m−2 s−1, 0–15.12 ng m−2 h−1 and 0–37.91 g m−2d−1, respectively. Most of the major fault zones at the study area are CO2 risk-free regions (CO2 concentration in soil gas < 5%). However, the extend of 222Rn pollution at the fault zones of F1, F4, F5 and F9 (the fault number) and that of Hg pollution at the fault zones of F2, F4, F5 and F7 were higher than the pollution level of 1. The annual emission of Hg and CO2 from the western margin of the Ordos block was estimated to be 2.03 kg and 0.70 Mt, respectively. Comprehensive analyses indicated that the higher emission rates of soil gases from the active fault zones were related to the seismic activities. The results suggest that the earthquake activity is a dominant factor enhancing the emission of 222Rn, Hg and CO2 from the solid earth through active fault zones and, furthermore, resulting great impact on the atmospheric environment. [ABSTRACT FROM AUTHOR]

Earthquakes result in overwhelming demand for medical resources at once, and affected areas requires reinforcement from neighbor cities. An effective allocation approach of medical rescue teams in early stage of disaster relief can improve rescue performance significantly. To find optimal allocation strategy, an integer nonlinear programming model is established, following utility principle. To construct the optimization model, stochastic transition probability of triage levels is introduced. Meanwhile, function from allocation scheme to fatalities of areas is established. Next, we design algorithm based on Lingo software to find solution of utility model. Finally, numerical experiments based on real data in 2008 Sichuan earthquake in China are used to compare utility approach with existing approaches in practice. The results of experiments indicate that: (1) to save more lives, a support team should preferentially be allocated to a worse and nearer affected area. When the worst area is not the nearest, the team also may be sent to an area with moderate severity and moderate distance. (2) Compared with severity strategy and distance strategy, utility strategy improves rescue efficiency significantly. [ABSTRACT FROM AUTHOR]

On 12 February 2014, a major earthquake occurred near the Yutian County, China. In this paper, the ionospheric variations around the time of this earthquake were analysed on the basis of the global positioning system vertical total electron contents (VTEC) and computerised ionospheric tomography (CIT) electron density distributions. Three ionospheric anomalies on 2, 17 and 19 February were detected with the global VTEC data from Center for Orbit Determination in Europe before and after the earthquake. Based on the analysis of the geomagnetic indices, we think the anomalies on 17 and 19 February could be related to the geomagnetic disturbances. Through further investigations on the temporal and spatial characteristics of the anomaly on 2 February, we draw the conclusion that the pre-earthquake ionospheric anomaly is probably the seismo-ionospheric precursor of the Yutian earthquake. In addition, the CIT results of the anomaly on 2 February were used to study the vertical distribution of this anomaly. The results showed that the ionospheric anomaly was mainly concentrated at the heights between 200 and 400 km. [ABSTRACT FROM AUTHOR]

The general characteristics of the recent horizontal crustal movement in the Chinese Mainland and the horizontal crustal movements before the Kunlun Mountain earthquake of M8.1 on Nov. 14, 2001 and two earthquakes of M 8.0 and M 7.9 occurred in Sept. 2003 around the Chinese Mainland are analyzed with GPS data obtained in the Crustal Movement Observation Network of China (CMONOC). Relative vertical displacements observed in the last five years at fiducial stations show that there was a significant correlation between the length of day and the vertical displacements at most stations in western China. [ABSTRACT FROM AUTHOR]

Mixture density networks (MDNs) are a class of neural network algorithms in the Bayesian framework that can invert for parameters and estimate the parameter uncertainties at the same time. We test MDNs by inverting the fault geometric parameters in a synthetic test with Okada's model and demonstrate the efficiency and robustness of the model. To further describe the MDNs algorithm, we invert regional static GPS displacement data for the 2013 Ms7.0 Lushan Earthquake in China to obtain the fault geometric parameters. The inverted geometric parameters, which are in the form of distributions, agree well with the published solutions for this event once the 99.7% confidence interval are taken into account. The 99.7% confidence intervals of the strike and dip angles are [ 187. 5 ∘ , 220. 4 ∘ ] and [ 20. 76 ∘ , 49. 76 ∘ ], respectively. To demonstrate the applicability of the inverted geometric parameters, we invert the slip distribution of the Lushan earthquake with the inverted parameters and GPS displacements. From the slip distributions considering the distributions of the parameters, we obtain the 99.7% confidence intervals of the magnitude Mw, maximum slip and depth of maximum slip, which are [6.51, 6.65], [0.30, 0.74] m and [9.43, 13.61] km, respectively. [ABSTRACT FROM AUTHOR]

On August 8, 2017, a Ms 7.0 earthquake occurred 5 km to the west of Jiuzhaigou National Park, causing 25 deaths and injuring 525. The objective of this study was to explore the seismogenic fault of the earthquake and tectonic dynamics of the source rupture. Field investigations, radon activity tests, remote sensing interpretations, and geophysical data analyses were carried out immediately after the earthquake. The Jiuzhaigou earthquake occurred at the intersection of the northern margin of the Minshan uplift belt and the south part of the Wenxian-Maqin fault in the south margin of the West Qinling geosyncline. There are two surface rupture zones trending northwest (NW), which are ground coseismic ruptures caused by concealed earthquake faults. The rupture on the southwest is the structure triggering the earthquake, along the Jiuzhaitiantang-Epicenter-Wuhuahai. The other one on the northeast (Shangsizhai-Zhongcha-Bimang) is a reactivation and extension of the secondary fault trending NW. The source rupture of this earthquake is a strike-slip shear fracture associated with the fault plane trending NW 331° and steeply dipping 75°, which is continuously expanding at both ends. The tectonic dynamics process of the source rupture is that the “Jiuzhaigou protrusion” is left-lateral sheared along the seismogenic fault in the NW direction. Finally, the Maqin fault and the arc fault system at the top of the “Wenxian protrusion” will be gradually broken through sometime in far future, as well as earthquaketriggered landslides will be further occurred along the narrow corridor between the seismogenic faults. The research results revealed the basic geological data and tectonic dynamic mechanism in this earthquake. [ABSTRACT FROM AUTHOR]

Ma’an Qiao Village, a Dai and Yi ethnic minority-based community in Sichuan Province, China sustained complete infrastructure devastation during the 2008 Panzhihua earthquake. Health emergency and disaster risk management (Health-EDRM) education intervention programs were implemented in 2010 and 2011. This serial cross-sectional survey study aimed to examine the immediate and long-term impacts of the Health-EDRM interventions in this remote rural community. The findings demonstrate knowledge improvement in areas of water and sanitation, food and nutrition, and disaster preparedness immediately after the Health-EDRM education interventions. Temporal stability of knowledge retention was observed in household hygiene and waste management and smoking beliefs in 2018, 7 years after the interventions. Other important findings include knowledge uptake pattern differences of oral rehydration solution (ORS) between earthquake-prone and flood-prone communities. Usage of Internet and mobile technology for accessing disaster-related information was found to be independent of gender and income. Overall, this study demonstrated the knowledge improvement through Health-EDRM education interventions in a remote rural community. Promoting behavioral changes through interventions to raise awareness has the potential to reduce health risks in transitional post-disaster settings. Future programs should aim to identify evidence-based practices and explore how technology can support Health-EDRM education among vulnerable subgroups. [ABSTRACT FROM AUTHOR]

In order to investigate the role of the amplification of peak ground acceleration (PGA) in seismic landslide formation mechanisms and study how earthquake waves interact with rock structures, a few strong-motion seismometers are installed at various locations on both sides of the Lengzhuguan gully. Five strong-motion seismometers were triggered at different depths in a tunnel at the same altitude during the Kangding Ms 5.8 earthquake on November 25th, 2014. The data reveal that the horizontal peak acceleration (PGA) at each site decreased with increasing site depths. The PGAH at the deepest monitoring site (99 m from the tunnel entrance) was approximately half that of the outermost site. The amplitude of the acceleration response spectrum was also attenuated from the entrance inwards, the dynamic magnification factor (β) of the standard acceleration spectrum was less than 3.5, and rate of change was the same as that for the amplitude acceleration response. The Fourier spectra of each monitoring site also decreased from the outside inwards, and the components of the Fourier spectra were more complex at the surface. [ABSTRACT FROM AUTHOR]

The upper Yangtze River region is one of the most frequent debris flow areas in China. The study area contains a cascade of six large hydropower stations located along the river with total capacity of more than 70 million kilowatts. The purpose of the study was to determine potential and dynamic differences in debris flow susceptibility and intensity with regard to seasonal monsoon events. We analyzed this region's debris flow history by examining the effective peak acceleration of antecedent earthquakes, the impacts of antecedent droughts, the combined effects of earthquakes and droughts, with regard to topography, precipitation, and loose solid material conditions. Based on these factors, we developed a debris flow susceptibility map. Results indicate that the entire debris flow susceptibility area is 167,500 km, of which 26,800 km falls within the high susceptibility area, with 60,900 km in medium and 79,800 km are in low susceptibility areas. Three of the six large hydropower stations are located within the areas with high risk of debris flows. The synthetic zonation map of debris flow susceptibility for the study area corresponds with both the investigation data and actual distribution of debris flows. The results of debris flow susceptibility provide base-line data for mitigating, assessing, controlling and monitoring of debris flows hazards. [ABSTRACT FROM AUTHOR]

The Longmenshan fault is a thrust fault which runs along the base of the Longmen Mountains in Sichuan province, southwestern China. The southern segment of the fault had two distinct responses to the Ms 8 Wenchuan and Ms 7 Lushan earthquakes. This study determines characteristics of the structural geology of the Longmenshan fault to evaluate how it influenced the two aforementioned earthquakes. This research was done within a Geo-information Technologies (GiT) environment based on multi-source remote sensing and crustal movement data extracted from the Global Positioning System (GPS). The spatial distribution of the southern segment of the Longmenshan fault zone was comprehensively analyzed to study both earthquakes. The study revealed that the Wenchuan and Lushan earthquakes occurred on two relatively independent faults. In addition, there was a nearly constant-velocity crustal movement zone between the two epicenters that probably had a compressive stress with slow motion. Furthermore, the central fault and a mountain back fault gradually merged from north to south. The Lushan earthquake was not an aftershock of the Wenchuan earthquake. The research showed that fault zones within 30-50 km of State Highway 318 are intensive and complex. In addition, crustal movement velocity decreased rapidly, with a strong multi-directional shear zone. Thus, activity in that zone was likely stronger than in the northern part over the medium to long term. [ABSTRACT FROM AUTHOR]

The Jinlong village landslide is located in Zitong County, Sichuan and approximately 150 km east of Wenchuan. The landslide has exhibited creep deformation for nearly 30 years. Field investigations indicated that the slope deformation was caused by the combined effects of unfavorable topographic and geological conditions and earthquakes. The sliding surface is along a contact between silty clay and mudstone. The Wenchuan earthquake accelerated the creep, causing bulging of the ground surface. Shear test results of the silty clay near the sliding surface indicated that the residual strength is consistent with the stability state of the landslide. The factors of safety were calculated using the limit equilibrium method (LEM) and the method of fast Lagrangian analysis of continua in two dimensions. The results using the LEM indicate that the stability is clearly affected by seismic shaking, and when the peak ground acceleration is 0.08 g, the slope reaches the limit state. The shear failure surface given by numerical simulation develops on the contact between the clay and silty mudstone, which confirmed the assumed sliding surfaces' location using the LEM. [ABSTRACT FROM AUTHOR]

This article focuses on the dynamics of using numbers to construct an image of social reality in disaster areas. Numbers are neither objective nor value-neutral but are rather generated, transmitted and shared with social signification. In other words, numbers can be thought of as simply socially constructed information. Statistics and other numbers usually work in positive ways. However, it is also possible that using numbers in the media can lead to unintended messages that could produce negative consequences. We conducted field studies in disaster-stricken areas of the 2008 Wenchuan earthquake in China and compared findings to the case of the 1995 Kobe earthquake in Japan in order to examine how numbers-in terms of the amount of donations, the timeline of reconstruction projects and casualty figures-construct social reality and cause a variety of social dysfunctions. [ABSTRACT FROM AUTHOR]

This present study examined the structure of posttraumatic stress disorder (PTSD) symptoms in a large sample of Chinese adolescents exposed to a deadly earthquake. A total of 2,800 middle school students aged 12 to 18 years participated in the study 6 months after the 'Wenchuan Earthquake'. Results of confirmatory factor analysis indicated that a five-factor intercorrelated model composed of intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal, fit data significantly better than both the four-factor numbing model King et al. (Psychological Assessment 10:90-96, ) and the four-factor dysphoria model Simms et al. (Journal of Abnormal Psychology 111:637-647, ). Further examination of the external convergent and discriminant validity revealed that except for the dysphoric arousal factor, the remaining four PTSD factors yielded significantly different correlations with external measures of anxiety vs. depression. The findings add to the limited literature on the factor structure of PTSD in youths and on the five-factor PTSD model. In addition, they provide more detail into the latent psychopathological processes of PTSD, and inform the forthcoming DSM-5. [ABSTRACT FROM AUTHOR]

The Yangtze River Delta region is an area highly vulnerable to flooding. As the population density is rising concomitantly with high economic growth, this region is becoming more vulnerable to natural hazards. We conducted a survey to investigate the individual risk perception of both the local authorities and the general community, analyze the current situation regarding risk management and identify problems in the current risk management scheme. Data were collected through questionnaires distributed to some members of the community and interviews with representatives of the local authorities. The primary findings are as follows: (1) risk and disaster multipliers perceived by lay people show the stigma effect of the Wenchuan earthquake; (2) the responses of college students illustrate that the stigma effect has less influence on people who have more knowledge about hazards; (3) differences exist in comparative groups (China and USA), which shows that the society and culture influence people's perception of risk; and (4) economic activities have complicated flood risk management such as land shortage, ground subsidence and flood diversion. Accordingly, the following measures should be taken: (1) the government should improve the risk communication and education of lay people; (2) the government must also control unsuitable land use and balance economic development and risk management; (3) flood diversion areas should be compensated through special funds collected from other cities; and (4) local governments should provide more support for hazard mitigation. [ABSTRACT FROM AUTHOR]

Earth fissures are a geohazard in Jiangsu Province, China. They can be caused by earthquakes and active faults, underground mining, groundwater extraction and landslides. In order to establish a provincial rehabilitation plan in Jiangsu, a range of monitoring programs, surveys, geological investigations and modeling have been implemented or planned. One of the focuses of the project is the land subsidence and earth fissures caused by excessive groundwater withdrawal in Suzhou, Wuxi and Changzhou (Su-Xi-Chang) area, southern Jiangsu Province. Hetang earth fissure within the Su-Xi-Chang area was first reported in 1995 and a series of investigation has been conducted since then. The site investigations and geophysical survey in 1997 have recognized the causative factor as the excessive groundwater drawdown coupled by the underlying bedrock ridge. An open trench excavation in 2007 and a plane strain analysis suggest that Hetang earth fissures may have cracked from the bedrock ridge to ground surface. Geological drilling in 2007 has further confirmed the existence and configuration of the ridge and extracted soil samples for laboratory tests to obtain soil parameters for numerical analyses and modeling of land subsidence and earth fissures in the Su-Xi-Chang area, Jiangsu, China. The laboratory tests are currently in progress and the result of numerical analyses and modeling is expected to be presented in the near future. [ABSTRACT FROM AUTHOR]