Automatic phase identification of earthquake based on the UBDN deep network

Seismic data obtained from seismic stations are the major source of the information used to forecast earthquakes. With the growth in the number of seismic stations, the size of the dataset has also increased. Traditionally, STA/LTA and AIC method have been applied to process seismic data. However, the enormous size of the dataset reduces accuracy and increases the rate of missed detection of the P and S wave phase when using these traditional methods. To tackle these issues, we introduce the novel U-net-Bidirectional Long-Term Memory Deep Network (UBDN) which can automatically and accurately identify the P and S wave phases from seismic data. The U-net based UBDN strongly maintains the U-net’s high accuracy in edge detection for extracting seismic phase features. Meanwhile, it also reduces the missed detection rate by applying the Bidirectional Long Short-Term Memory (Bi-LSTM) mode that processes timing signals to establish the relationship between seismic phase features. Experimental results using the Stanford University seismic dataset and data from the 2008 Wenchuan earthquake aftershock confirm that the proposed UBDN method is very accurate and has a lower rate of missed phase detection, outperforming solutions that adapt traditional methods by an order of magnitude in terms of error percentage.

Survival or Crisis? Funding Distribution from Grant-Making Foundations to Grassroots Social Organizations in China

The 2008 Wenchuan earthquake increased the need for disaster relief and reconstruction projects in China. This disaster created an upsurge of Chinese grant-making foundations, which then increased funding expectations. Many grassroots social organizations (SOs) in China believed that going forward, this level of funding would continue. However, the majority of grassroots SOs in China are currently facing an existential crisis. Their survival is being threatened by a shortage of funding from both local and foreign grant-making foundations. This research uses an empirical analysis of grant-making foundations and in-depth interviews, as well as observational evidence accumulated over a 10-year period, to explore the distribution of funding from foundations to grassroots SOs in China. The findings show that there are a limited number of Chinese grant-making foundations and that the foundations that exist do not include grassroots SOs in their funding scheme.

Spatiotemporal Evolution of Earthquakes in Longmenshan Fault and Adjacent Area, before and after the 2008 Wenchuan Earthquake

Seismicity sequence following a main earthquake usually contains much meaningful information for unveiling the focal mechanism and predicting the reoccurrence interval of large earthquakes. The spatiotemporal evolution of earthquakes before and after the 2008 Wenchuan earthquake (Ms 8.0) is analysed comprehensively in this study. The frequency-magnitude relation of the 3493 earthquake events retrieved from the database of the International Seismological Centre indicates that the adopted catalogue is complete for magnitudes ≥Ms 3.4. The seismicity during the 10 years before the Wenchuan earthquake remained stable, including the magnitudes and focal depths. However, seismicity attenuated sharply in the year following the Wenchuan earthquake, and the magnitude of earthquakes before the Wenchuan earthquake decreased gradually. The area of the seismogenic zone of the 2008 Wenchuan earthquake was smaller than the earthquake stricken area. The earthquakes that occurred in the Longmenshan fault area and adjacent area in the study period were mainly shallow earthquakes. The focal depths of earthquakes in the study area became stable gradually after the Wenchuan earthquake, mainly within the range from 10 to 16 km. The earthquakes in the study area were mainly distributed with an along-dip distance of 0–20 km, and the seismicity was distributed uniformly along the fault strike.

Support for a “Jelly Sandwich” Model of the Tibetan Plateau

Computer modeling constrained by positional data collected in the aftermath of the 2008 Wenchuan earthquake indicates the lower crust is less viscous than the upper mantle below it.

Spatial and Temporal Distribution of Geologic Hazards in Shaanxi Province

The spatio-temporal distribution of geological hazards, including collapses, landslides, and debris flows, in Shaanxi province, China was studied based on data from 1951 to 2018. The potential impact factors, including the geomorphologic types, rivers, roads, rainfall, and earthquakes, were analyzed using Random Forests. The results indicated that most hazards occurred in summer (i.e., July–September) and were triggered by rainstorms. The freeze–thaw effect had a considerable contribution to hazards in the north. Spatially, most hazards in the north occurred in valley terraces of the Loess Plateau, while medium-relief terrane (relief ranged from 500 to 1000 m) in the southern Qinling Mountains were hazard-prone areas. The collapses and landslides were mainly affected by human factors in Northern Shaanxi, whereas in Southern Shaanxi geomorphology was the primary factor. Permeability was a dominant factor for debris flows. In addition, the 2008 Wenchuan earthquake had a remarkable influence on the spatial distribution of hazards. In contrast, for the situation in the Sichuan province, which was close to the earthquake epicenter, the Wenchuan earthquake triggered many collapse and landslide events in the southwest regions of Shaanxi province only on 12 May 2008. The thresholds for the three hazard types in the north and south regions were almost the same despite their distinctly different geologic characteristics. Through a sensitivity analysis, we found an appropriate dry period of 12 h for the area.

Optimization of Warehouse Location and Supplies Allocation for Emergency Rescue under Joint Government–Enterprise Cooperation Considering Disaster Victims’ Distress Perception

The location and allocation of emergency supplies are an important part of emergency rescue work. The existing emergency location and allocation process is inefficient, costly, and neglects the psychology of victims. To improve the emergency relief work and solve the current problems, this paper introduces the victims’ pain perception cost into the model, takes the lowest cost of the whole emergency rescue system as the goal, constructs a government–enterprise joint emergency material location–allocation model, and uses the simulated annealing algorithm to solve the model. This paper takes the 2008 Wenchuan earthquake in Sichuan Province as the background and verifies the validity and rationality of the model through a comparative analysis of case simulations. The results show that the model and algorithm can effectively solve the emergency supplies location–allocation problem considering the victims’ pain perception, reflecting the idea of human-centered sustainable development and providing support for building a sustainable emergency relief system.

Changes Over Time in Post-traumatic Stress Disorder Among Children Who Survived the 2008 Wenchuan Earthquake and Predictive Variables

Background: This study examines changes over time in post-traumatic stress disorder (PTSD) among children who survived the 2008 Wenchuan earthquake and the relevant predictive variables.Methods: A total of 203 children and adolescents were investigated 24 months after the earthquake, and 151 children and adolescents completed the 1-year follow-up study. Participants completed the Children's Revised Impact of Event Scale (CRIES-13), the Center for Epidemiologic Studies Depression Scale (CES-D) and the Connor-Davidson Resilience Scale (CD-RISC). Hierarchical linear regression analysis was used to evaluate the predictors of changes in PTSD severity.Results: Eighty percent of the children still had some PTSD symptoms 2 years after the Wenchuan earthquake, and 66.25% of the children had symptoms that lasted 3 years. In the model predicting PTSD symptom severity, the loss of family members and child burial explained a significant 21.9% of the variance, and depression explained a significant 16.7% of the variance. In the model predicting changes in PTSD severity, the change scores for resilience and depression explained a significant 18.7% of the variance, and cognitive behavioral therapy (CBT) explained a significant 33.6% of the variance.Conclusions: PTSD symptoms in children and adolescents can persist for many years after trauma. In addition to using psychological interventions to improve PTSD symptoms, improvements in depression and resilience should also be considered.