China Wenchuan Research Articles

Landslide topology uncovers failure movements

The death toll and monetary damages from landslides continue to rise despite advancements in predictive modeling. These models’ performances are limited as landslide databases used in developing them often miss crucial information, e.g., underlying movement types. This study introduces a method of discerning landslide movements, such as slides, flows, and falls, by analyzing landslides’ 3D shapes. By examining landslide topological properties, we discover distinct patterns in their morphology, indicating different movements including complex ones with multiple coupled movements. We achieve 80-94% accuracy by applying topological properties in identifying landslide movements across diverse geographical and climatic regions, including Italy, the US Pacific Northwest, Denmark, Turkey, and Wenchuan in China. Furthermore, we demonstrate a real-world application on undocumented datasets from Wenchuan. Our work introduces a paradigm for studying landslide shapes to understand their underlying movements through the lens of landslide topology, which could aid landslide predictive models and risk evaluations.

Coupling coordination analysis of the economy-ecology-society complex systems in China's Wenchuan earthquake disaster area

Natural disasters have a profound and far-reaching impact on human society, economic progress, and ecological stability. Swift post-disaster reconstruction, aiding economic recovery, and minimizing social losses are paramount for attaining sustainable development in afflicted regions. This study delves into the coupling and coordinated development of the economic-ecological-social (EES) complex system during the post-disaster reconstruction following the Wenchuan earthquake in China. Using data spanning from 2005 to 2020, we constructed a comprehensive indicator system for the EES complex system. Subsequently, a coupled evaluation framework was established to assess its sustainable and coordinated development. Employing the AHP-entropy method and the coupled coordination degree model (CCD), we explored the interrelationships within the EES complex system. The results indicate that the CCD of the EES system in Wenchuan exhibited an upward trend in the decade following the earthquake, significantly expediting sustainable development in the disaster-stricken area. Geographically, CCD scores increased from the northeast to the southwest, revealing distinct stratification differences. Furthermore, CCD closely correlated with geographic location, ecological resource endowment, science and education, and the labor force. The study also analyzed spatial discrepancies in CCD scores and identified underlying factors. Based on these findings, we offer policy recommendations to fortify infrastructure development, reconfigure industrial layout, and heighten environmental consciousness. These results offer valuable insights for decision-making in post-disaster recovery and sustainable development.

Well-being Effects of Natural Disasters: Evidence from China's Wenchuan Earthquake.

The online version contains supplementary material available at 10.1007/s10902-022-00609-z.

The prevalence of posttraumatic stress in adolescents eight years after the Wenchuan earthquake

In 2008, an 8.0 Richter scale earthquake devastated Wenchuan in China, which resulted in heavy casualties, and had wide-reaching psychological effects on survivors. To examine its impact on the survivors, this study aims to investigate the prevalence of posttraumatic stress disorder (PTSD) and posttraumatic growth (PTG) in adolescents eight years after the earthquake. The cross-section survey was conducted in two different earthquake-affected areas, and data were collected from 4118 respondents. Instruments included the questionnaire on demographic information, the questionnaire on seismic exposure, PTSD Checklist-Civilian Version (PCL-C) questionnaire, Posttraumatic Growth Inventory (PTGI), Perceived Social Support Scale (PSSS) and Simple Coping Style Questionnaire (SCSQ). During the survey, there were 1998 valid questionnaires from the generally affected area and 2120 questionnaires from the severely affected area. The rate of PTSD is 1.9% in the generally affected area and 2.7% in the severely affected disaster area; there is no significant difference between the two differently affected areas. Occurrences of PTSD and PTG are significantly positively correlated in the generally affected area, nevertheless, there is a significant negative correlation between PTSD and PTG in most systems of the severely affected area. The results of this study help to expand our knowledge regarding posttraumatic stress in adolescents 8 years after the Wenchuan earthquake, and it provides suggestions for specific long-term health interventions in such populations. To prevent earthquake-related psychological issues among adolescent survivors, social support, psychological aid, and improvement of the living environment are necessary to buffer negative posttraumatic stress.

Performance of the reinforced right abutment slope of Zipingpu Dam during magnitude 8.0 earthquake, Wenchuan, China

On 12 May 2008, an earthquake of magnitude 8.0 on the Richter scale occurred at Wenchuan in China. Zipingpu dam also experienced the earthquake. The maximum ground acceleration near the top of the 156 m high rockfill dam exceeded 2 g . The right dam abutment slope, which accommodates all the discharge facilities, remained intact after this severe earthquake. However, the natural slopes on the opposite side of the reservoir were severely damaged. It has been found that the reinforcement provided by more than 1000 prestressed cables in the right abutment slope helped to stabilize it. Measurements from multipoint extensometers and load cells installed in the slope showed that there were sudden changes in displacement and stress during the earthquake. This is clear evidence that reinforcement with anchored cables can be successfully used to stabilize a slope.

Relationships between Sleep Problems and Psychiatric Comorbidities among China's Wenchuan Earthquake Survivors Remaining in Temporary Housing Camps.

Earthquake survivors are a diverse population. This study focused on a special group of earthquake survivors, who had still stayed in temporary housing camps for about 2 years after China's Wenchuan Earthquake rather than those who moved back to rebuild their lives or immigrated to large cities to seek new lives. The research goals were to (1) assess their sleep problems as well as their PTSD, depression and anxiety and (2) examine the relationship between different dimensions of sleep quality and PTSD, depression, and anxiety among these survivors. Three-hundred and eighty seven earthquake survivors who remained in temporary housing camps and had sleep problems were recruited 17–27 months after Wenchuan Earthquake. Four standardized instruments-The Pittsburgh Sleep Quality Index, PTSD Checklist-Civilian Version, Self-rating Depression Scale, Self-rating Anxiety Scale, and face-to-face one-on-one structured interviews were used to assess these survivors' sleep quality, PTSD, depression, and anxiety. It was found that (1) 83.20% of these survivors reported having sleep problems, and 79.33% of them considered insomnia as the most common sleep problem; (2) 12.14% suffered PTSD, 36.43% experienced depression, and 38.24% had anxiety; (3) sleep disturbance, sleep medication use, and subjective sleep quality were significantly related to PTSD; (4) habitual sleep efficiency, sleep disturbance, sleep medication use, and daytime dysfunction were significantly related to depression; and (5) sleep disturbance, sleep medication use, and daytime dysfunction were significantly related to anxiety. Clinic implications of the study are discussed.

Ionospheric precursor of 2008 China Wenchuan earthquake using two-dimensional principal component analysis

Two-dimensional principal component analysis (2DPCA) has been used to examine ionospheric total electron content (TEC) during the time period from 7 to 12 May 2008, which was five days before China's Wenchuan earthquake (Mw=7.9) at 06:28:00 UT on 12 May 2008 with the epicentre of | (31.119°N, 103.258°E). A TEC precursor represented with a larger principal eigenvalue was detectable during the time period from 02:00–04:00 UT (10:00–12:00 LT) on 9 May 2008 over the epicentre for the duration of approximately 2 hours.

The Application of Cumulative Sum Feature Extraction Algorithm in Data Stream Anomaly Analysis before Earthquake

A cumulative sum feature extraction algorithm for anomaly analysis before earthquake is proposed by using the cumulative sum feature extraction algorithm. The analysis results reveal that the anomalous variations exist prior to the earthquakes. The methods studied in this work include cumulative sum, smooth using the Technology of Locally weighted smoothing and compute feature points. These methods have been applied to analyze the anomaly from OLR data that correspond to seismic precursors, particularly to a comparative study of the two earthquakes of Wenchuan in China and one earthquake in eastern Japan.

Damages of the Shaohuoping road tunnel near the epicentre

Numerous infrastructures including national roads, tunnels, etc. in Sichuan Province were damaged to various extents in China's Wenchuan earthquake in 2008. The Shaohuoping road tunnel, near the epicentre of the earthquake, was the typical damaged one. The damage modes of different parts of the Shaohuoping tunnel were summarised based on the spot investigation data. It was found that various damages involving cracking and spalling of concrete lining were observed on different parts of the tunnel. The earthquake damages of critical positions, portal section and body portion, were simulated and analysed by finite element numerical model proposed in this paper. Influences of vertical motion on seismic responses of the tunnel were also studied by means of the finite element simulation. The simulation responses were compared with the spot investigations of earthquake structural damages to different parts of the tunnel. The comparisons showed a good agreement, which indicated that, the damage mechanism of the tunnel can be predicted reliably by the proposed finite element model. Furthermore, the results show that the damage of different parts of the tunnel is mainly controlled by horizontal ground motions, but the tunnel may suffer more damages with the effect of the vertical motion.

Research on Performance Evaluation of Reconstruction Projects in Earthquake-stricken Area by Using FAHP-Example for 5.12 Wenchuan in China

Research on Performance Evaluation of Reconstruction Projects in Earthquake-stricken Area by Using FAHP-Example for 5.12 Wenchuan in China

Family function and depression in relatives of earthquake victims: a survey conducted one year after China's Wenchuan Earthquake

The Wenchuan Earthquake that hit Sichuan, China in 2008 not only caused huge losses in terms of human life and economic damage. It also caused psychological trauma in survivors, especially those who had lost relatives and close friends (bereaved). In the aftermath of earthquakes, bereaved individuals require family and spiritual renewal in addition to material assistance. This study investigated the status of and relationship between family function and depression in bereaved individuals living in areas devastated by the Wenchuan Earthquake. Results provide baseline information for post-disaster family reconstruction. This cross-sectional study surveyed 264 qualified bereaved individuals who lived in an area hard hit by the Wenchuan Earthquake. Face-to-face interviews were administered based on the family APGAR(adaptation, partnership, growth, affection, resolve) index and Hamilton depression (HAMD) scale. The mean family function score for participants was 6.52 ± 2.65. Results for half (50.0%) of participants indicated "good" family function. Results indicated marital status, family structure and status of having another baby as factors that significantly influence family function (p < .05). Participants' mean depression score was 40.41 ± 9.35, with all (100%) of participants demonstrating symptoms of depression. The 5 most prevalent depressive symptoms were: depressed mood, decreased interest in work, mental anxiety, diminished capacity and agitation. Results showed marital status, leisure frequency, economic status, and having another baby as factors that significantly influenced family function (p < .05). A Pearson's correlation analysis indicated no significant relationship between level of depression and family function (p >.05). Family functions of the bereaved living in areas hard hit by the Wenchuan Earthquake were all undermined to varying degrees. Although participants all exhibited depressive symptoms, this study found no affect of such symptoms on family functions. Interventions delivered in the months and years after an earthquake should be tailored to address each individual's depression status. Interventions should also help these individuals learn to improve and enhance family functions to effectively reduce negative behaviors and reactions in order to better promote physical and mental health.

Potential reasons for ionospheric anomalies immediately prior to China's Wenchuan earthquake on 12 May 2008 detected by nonlinear principal component analysis

Nonlinear principal component analysis (NLPCA) is used to detect total electron content (TEC) anomalies for China's Wenchuan earthquake on 12 May 2008 (UT) (Mw=7.9). NLPCA is applied to global ionospheric maps (GIMs) at height ranging from 150 to 200km with transforms conducted for the time period 00:00–06:00UT on 12 May 2008. The GIMs are analyzed using NLPCA whereby the GIMs are separated into 100 smaller maps of 36° in longitude and 18° in latitude. These smaller maps are constructed at 71×71 pixels forming the transform matrix of the NLPCA. The transform allows for a principal eigenvalue to be assigned for each of the smaller maps. The results of the transforms provide 100 principal eigenvalues covering the region and the epicenter of the Wenchuan earthquake. The possibility of TEC anomalies being caused by X-ray flux and geomagnetic activity is eliminated by reviewing X-ray flux data and the Kp index. The eigenvalues of NLPCA are compared with the eigenvalues of principal component analysis (PCA), and TEC anomalies are clearly detected using NLPCA. Large principal eigenvalues representative of earthquake-related TEC anomalies were found nearby the epicenter for the time period 00:00–0600UT using NLPCA. The earthquake occurred at 06:28UT. A potential cause of the clear TEC anomaly almost directly over the epicenter in the time period 0200–0400 would be very stark p-type semiconductor effects caused by rocks under extreme stress. The stress may have abated during other time periods reducing p-type semiconductor effects and associated TEC anomalies.

Spatial pattern of a seismo-ionospheric signature using principal component analysis

This article uses principal component analysis (PCA) to determine the spatial pattern of total electron content (TEC) anomalies in the ionosphere corresponding to China's Wenchuan Earthquake of 12 May 2008 UTC (Mw = 7.9). PCA is applied to global ionospheric maps (GIMs) with transforms conducted for the time period from 08:00 to 10:00 UT on 9 May 2008. The GIMs are subdivided into 100 smaller maps (36° longitude and 18° latitude). The smaller maps (71 × 71 pixels) form the transform matrices of corresponding dimensions (2 × 1) through image processing. The transform allows for extreme principal eigenvalues to be assigned to the seismo-ionospheric signature described by Zhao et al. [2008, Is an unusual large enhancement of ionospheric electron density linked with the 2008 great Wenchuan earthquake? Journal of Geophysical Research, 113, A11304, doi: 10.1029/2008JA013613.]. Results show that the range of the TEC anomaly declines with height; however, the anomaly becomes more localized and intense at higher altitudes (250–300 km), giving the anomaly the spatial pattern of a downward-facing trumpet.

Lessons Learned from the Damaged Huilan Interchange in the 2008 Wenchuan Earthquake

A disastrous earthquake struck Wenchuan in China’s Sichuan province in 2008 and caused heavy casualties and structural damage to bridges and buildings. One of the two severely earthquake-damaged curved bridges in China, the Huilan interchange, had been carefully studied, including postearthquake investigation and identification of the cause of failure for this bridge. The Huilan interchange, constructed in 2004 in Mianzhu City, consisted of a viaduct and four horizontally circular ramp bridges with continuous box girders. Field investigations found that the seismic damage to the ramp bridges was especially heavy, one or two short piers in all, but one of the ramp bridges experienced severe failure, and the box girders over the failed piers were fractured. Other piers of the ramp bridges suffered minor-to-moderate damage, including concrete cover spalling, concrete cracking, and slippage damage of the rubber bearings. The viaduct suffered only slight damage, including slippage damage of the rubber bearings and pounding damage of the superstructure. The seismic performance of the bridge was evaluated by finite-element modeling and compared with field observations. It was found that the bearing on top of the shortest pier, Pier 1, was damaged first. Then, the seismic action was concentrated on the next shortest pier, Pier 2, which had the largest flexural stiffness. Pier 2 first yielded in flexure, and, as the lateral displacement increased, the ultimate response of this pier was dominated by its shear capacity, and it eventually failed in flexure-shear mode.

The role of telecommunication in the rescue process of large scale disaster &amp;ndash; case study of China's WenChuan earthquake in 2008

On May 12, 2008, a strong earthquake measuring 8 on the Richter scale struck Wenchuan County in Sichuan province, which is located in the southwest of China. During the rescue process of this large scale disaster, modern telecommunication played a very important role. To identify the key roles of telecommunication in the earthquake rescue process, this paper reviews the rolling news reports about the rescue efforts in the first week after the earthquake (May 12-19, 2008). The purpose of this case study is to facilitate discussions among researchers and practitioners about the future applications of telecommunication technologies in the large scale, disaster rescue process.

Applying lessons from China's Wenchuan earthquake to medical rescue following the Yushu earthquake

AbstractA 7.1‐magnitude earthquake hit China's Qinghai province—4000 meters above sea level, on April 14, 2010, just 702 days after Wenchuan Earthquake. As of 12:00 on April 19, the death toll stood at 1706, with 256 missing and 12,128 injured. West China Hospital (WCH), a regional state‐level hospital of the Ministry of Health, sent a medical team with relief supplies within the first hour after Yushu earthquake and the team rushed to Yushu in the first day participating golden seventy‐two hours rescue effort. The second day after Yushu earthquake, medical apparatuses and drugs valued at 5 million RMB were delivered to the rescue site and the second batch of medical team were positioned. Within 33 hours of the earthquake, 102 people, including 93 with earthquake‐related injuries and 9 armed police with severe altitude sickness, were send to WCH by air in four batches. WCH organized its medical rescue efforts based on first‐hand experience with medical rescue following Wenchuan earthquake, a series of evidence‐based diagnosis and treatment standards, and “four concentration principles,” namely concentrating the wounded, experts, resources, and treatments. Of the 93 cases with earthquake‐related injuries, 54 were seriously wounded, and in the five days immediately following the earthquake, 58 underwent operations and none died. The experience learned from Wenchuan earthquake have been used, improved and sublimated more rapidly, appropriately, and effectively in the Yushu earthquake medical rescue.