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The living heritage approach seeks to link heritage properties with the living dimensions attributed by local communities - tangible and intangible heritage. However, how living heritage can be further understood and managed in post-disaster traditional settlements has yet to be explored adequately. This paper discusses the concept of living heritage embedded in post-earthquake planning and reconstruction of traditional settlements in Jiuzhaigou Valley, a World Heritage property in Sichuan Province. The thematic analysis method is employed to conduct both deductive and inductive content analysis of governmental administrative documents on post-earthquake reconstruction policies and practices. The results demonstrate that the continuity of heritage and the continuity of community are the two essential attributes conceptualizing living heritage by developing a people-centered approach to resilience-building in post-disaster traditional settlements. The paper broadens the concept of living heritage by incorporating the discussion of heritage and traditional settlements into a post-disaster context. The living heritage approach can be further elaborated into an integrated heritage management approach relying on community values and empowerment, to promote urban and rural conservation and urbanization policy-making and practices worldwide. [ABSTRACT FROM AUTHOR]

One of the primary tasks for effective disaster relief after a catastrophic earthquake is robust communication. In this paper, we propose a simple logistic method based on two-parameter sets of geology and building structure for the failure prediction of the base stations in post-earthquake. Using the post-earthquake base station data in Sichuan, China, the prediction results are 96.7% and 90% for the two-parameter sets and all parameter sets, respectively, and 93.3% for the neural network method sets. The results show that the two-parameter method outweighs the whole parameter set logistic method and the neural network prediction and can effectively improve the accuracy of the prediction. The weight parameters of two-parameter set by the actual field data significantly show that the failure of base stations after earthquake is mainly due to the geological differences where the base stations are located. It can be envisioned that if the geological distribution between the earthquake source and the base station is parameterized, the multi-parameter sets logistic method can not only effectively solve the failure prediction after earthquakes and the evaluation of communication base stations under complex conditions, but also provide site selection evaluation for the construction of civil buildings and power grid towers in earthquake-prone areas. [ABSTRACT FROM AUTHOR]

Identifying the types of disasters and analyzing the distribution pattern of and the spatial correlation between villages and disasters are important prerequisite for the disaster prevention and mitigation of traditional villages. Taking Aba Tibetan and Qiang Autonomous Prefecture as an example and using the tools of kernel density evaluation and spatial statistics, this paper analyzes the distribution pattern of and the spatial correlation between traditional villages and typical geological disasters on the three spatial scales of Aba Prefecture, village agglomeration area, and village administrative area with necessary explanations. It concludes that most of the traditional villages in Aba Prefecture agglomerate in the middle- and high-level alpine gorges and some are clustered at either the border area or the central hinterland of counties; with the increase of maximum seismic intensity and frequency of earthquakes, it appears there is an increase of traditional villages and their trend of agglomeration, which implies an overlap of the areas of dense traditional villages and high-density geological disasters, as well as the synchronous increase of traditional village density and geological disaster density; and the traditional villages in Aba Prefecture are affected by multiple disasters, in particular landslide and debris flow. Finally, the paper discusses the issue of disaster prevention and mitigation in the protection and development planning of traditional villages. [ABSTRACT FROM AUTHOR]

Several possible lithosphere–atmosphere–ionosphere coupling mechanisms before earthquake occurrence are presented in the literature. They are described by several models with different interaction channels (e.g., electromagnetic, mechanics, chemical, thermal), sometimes in conflict with each other. In this paper, we search for anomalies six months before the Lushan (China) 2013 earthquake in the three geo-layers looking for a possible view of the couplings and testing if one or another is more reliable to describe the observations. The Lushan earthquake occurred in China's Sichuan province on 20 April 2013, with a magnitude of Mw = 6.7. Despite the moderate magnitude of the event, it caused concern because its source was localized on the southwest side of the same fault that produced the catastrophic Wenchuan event in 2008. This paper applies a geophysical multi-layer approach to search for possible pre-earthquake anomalies in the lithosphere, atmosphere, and ionosphere. In detail, six main increases in the accumulated seismic stress were depicted. Anomalous geomagnetic pulsations were recorded in the Chengdu observatory, sometimes following the increased stress. Atmosphere status and composition were found to be anomalous in several periods before the earthquake, and, spatially, the anomalies seem to appear firstly far from the upcoming earthquakes and later approaching the Longmenshan fault where the Lushan earthquakes nucleated. The Formosat-3 data identified interesting anomalies in the altitude or electron content of the ionospheric F2 peak in correspondence with seismic and atmospheric anomalies 130 days before the earthquake. In addition, the total electron content showed high anomalous values from 12 to 6 days before the earthquake. We compared the anomalies and tried to explain their correspondences in different geo-layers by the lithosphere–atmosphere–ionosphere coupling models. In particular, we identified three possible couplings with different mechanisms: a first, about 130 days before the earthquake, with a fast (order of one day) propagation delay; a second, about 40 days before the earthquake occurrence, with a propagation delay of few days and a third from 2.5 weeks until one week before the event. Such evidence suggests that the geo-layers could interact with different channels (pure electromagnetic or a chain of physical-chemical processes) with specific propagation delays. Such results support the understanding of the preparation for medium and large earthquakes globally, which is necessary (although not sufficient) knowledge in order to mitigate their impact on human life. [ABSTRACT FROM AUTHOR]

This paper analyzed the strong motion characteristics based on 86 three-component strong motion records of the MW 6.6 Luding earthquake. Additionally, the factors that influence the variation in ground motion for three earthquakes with similar magnitude in Sichuan Province were investigated. The analysis result indicates a strong correlation between the observed ground motion parameters and the distribution of published Modified Mercalli Intensity. The residual analysis reveals that the spectral accelerations at periods 0.1–10.0 s are amplified to 0.0798–0.3057 times the mean level in the rupture forward direction and weakened to 0.0738–0.2831 times the mean level in the rupture backward direction. The maximum pulse direction recorded by the 51LDJ station is N6°E, aligning with the vertical fault direction. The velocity pulses has distinct bidirectional pulses in the waveforms, with a PGV of 37.0 cm/s. The source effect of the strike-slip MW 6.6 Luding and MW 6.5 Jiuzhaigou earthquakes on ground motion is relatively less significant compared to the average level of mainshocks in southwest China. However, the thrust-fault MW 6.7 Lushan earthquake exhibits a stronger source effect on ground motion during short and medium periods, but a weaker source effect during long periods when compared to the average level. The anelastic attenuation of the Longmenshan, Xianshuihe, and Huya fault zones in Sichuan exhibits significant regional variation and periodic correlation. This phenomenon is closely linked to the regional tectonic background variations and the heterogeneity of crustal structure within the area. [ABSTRACT FROM AUTHOR]

Climate change is very important for the distribution of plant resources, especially for crops. Angelica plants have a long history of use and significant crop resources in China, whose rhizomes are extensively used in medicine and food. In this paper, 1599 georeferenced herbarium records were analyzed using DIVA-GIS, and the ecological distribution and richness of the current and future distribution simulation were analyzed using the MaxEnt model. The results show that they are from 32 provinces in China. Among these provinces, Sichuan, Gansu, and Yunnan have the largest number of herbariums. According to the MaxEnt model simulation, it is found that the precipitation in the warmest season, annual precipitation, and the driest monthly precipitation are the foremost bioclimatic variables that control the distribution of eight selected Angelica plants (A. biserrata, A. gigas, A. laxifoliata, A. likiangensis, A. longicaudata, A. omeiensis, A. polymorpha, and A. valida). It can be seen from the potential distribution map that the suitable growth areas of A. polymorpha and A. valida have increased, while the suitable growth areas of the six species of Angelica have decreased in varying degrees, 18.24%, 20.01%, 9.91%, 53.16%, 10.06%, and 12.64% respectively. Therefore, it is necessary to protect the Angelica plants. [ABSTRACT FROM AUTHOR]

The earthquake-induced barrier lakes that are caused by landslides are at risk of bursting after excessive rainfall, and they are a serious threat to the surrounding residents. This paper proposes a change detection approach of the barrier lake using the method of post-classification comparison combined with background subtraction. The case studied in the paper is the detection of the Tangjiashan barrier lake, which is one of the largest lakes induced by the Wenchuan Earthquake on 12 May 2008. Both the pre- (31 March 2007) and post-earthquake (16 May 2008) images of the Advanced Land Observing Satellite (ALOS) Advanced Visible and Near Infrared Radiometer type 2 (AVINER-2) were collected in the paper. The results show that the river widened through the Zhangping area, increasing from 90 m pre-earthquake to 545 m post-earthquake, and the surface area of the barrier lake increased from 0.945 km2 to 1.471 km2. [ABSTRACT FROM AUTHOR]

This paper aims to systematically study kinematic characteristics of Wenjiagou rock avalanche triggered by the M8.0 2008 Wenchuan earthquake and one of subsequent debris flows that occurred on August 13, 2010 (8.13 debris flow), using a numerical approach. The kinematic characteristics of the rock avalanche are back-calculated using an energy-based runout model. The erosion process of the subsequent rainfall-induced debris flow is analyzed using a progressive scouring entrainment model incorporated in the energy-based runout model. The results indicate that Wenjiagou rock avalanche traveled farther than most other rock avalanches with a maximum velocity of approximately 73 m/s detected at about 1700 m away from the source zone. The erosion of the 8.13 debris flow mainly occurred right after the dam failure which contributes to more than 97% of the total eroded volume. Besides, four different scenarios, including no blockage of the runoff (scenario I), no dam failure (scenario II), dam failure at the end of precipitation (scenario III), and no erodible material (scenario IV), are supposed to study the effect of the failure of a check dam on the erosion characteristics of the debris flow. The results reveal that the blockage of the channel without failure could reduce 86% of the total volume and the failure of check dams is the main reason for the destructive consequence of the 8.13 debris flow. This paper proposes an approach to explore kinematic characteristics of a rock avalanche and erosion process of the subsequent rainfall-induced debris flows and also innovatively provides a method to indirectly assess mitigation strategies that can be used for the design of mitigation projects. [ABSTRACT FROM AUTHOR]

Extremely hard-hit areas face frequent secondary geological hazards and difficulties in vegetation recovery, and subsequent effects have a significant impact on land cover changes. At present, there is a lack of research on the dynamic restoration of, and changes in, the ecological environment before and after an earthquake, and especially a lack of quantitative assessment of the impact of earthquakes on land cover at the microscopic scale of spatial distribution of landscape indices. Taking the Lushan earthquake in Sichuan Province as an example, this paper obtained land cover data from the study area between 2012 and 2020, and analyzes the spatial distribution characteristics and influencing factors of land cover change frequency by using a comprehensive land cover degree index, land cover transfer matrix and landscape ecology index. The results show that the types of cropland, forest, built-up and bare land have changed significantly in the study area. During the earthquake recovery period, the comprehensive land cover index of the study area showed an increasing trend, and land cover has been continuously improved under the effect of artificial measures and natural restoration. After 2013, patch density (PD) and landscape shape index (LSI) values decreased and aggregation index (AI) values increased for the vast majority of landscape land classes, indicating a benign ecological development across the region in the post-earthquake period. The research results are not only helpful to establish scientific ecological environmental management in the earthquake-stricken areas, but also helpful to formulate medium- and long-term ecological environmental monitoring and ecological restoration plans based on land cover change patterns. [ABSTRACT FROM AUTHOR]

In China, many geological hazards occurred in remote mountainous regions, and it was time-consuming to disseminate disaster information for the responsible parties to make timely judgements. Besides, only relying on professionals to monitor and manage disasters was demanding and costly. The Chinese government created a system to engage residents in the process of disaster risk management, namely 'Public Participation Monitoring and Warning' (PPMW), to disseminate timely disaster information and bring down management costs. The objective of this system was to reduce casualties with minimum cost by organizing residents to evacuate from disasters in advance. This paper introduced the PPMW system, including its structure, operation mechanism by reviewing government documents and research articles, and its implementation by a case study of a landslide at Boli village (E 101°01′, N 27°29′), Yanyuan County, Sichuan Province, China on July 19th 2018. Further, this paper analyzed the strengths and limitations of the system and discussed its future development. It had the potential to become an affordable disaster risk management tool for other countries facing similar situations to China. [ABSTRACT FROM AUTHOR]

This paper proposes that the future is uncertain for many children. Both natural and human-made disasters are adversely affecting the lives of millions of children and their families. An example of an environment-related disaster is cited from Sichuan Province, China, where a massive earthquake killed some 70,000 people in 2008. How the teachers responded to such a disaster is explained through drawings by the children illustrating their feelings. This paper discusses how early childhood teachers can prepare children before, during and after disasters. Various strategies are discussed including, facilitating children's expressions of emotions, empathy, and resilience in the face of adversity. The use of dramatic play and storytelling are discussed with examples that can be a stimulus for curriculum development. The role of the teacher is viewed as critical in helping children readjust to life and regain some semblance of well-being. [ABSTRACT FROM AUTHOR]

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The problem of large deformation is very prominent in deep-buried tunnel excavation in soft rock, which brings serious potential safety hazards and economic losses to projects. The knowledge of deformation law and support measures is the key to ensure the rational design and safe construction in a large deformation tunnel of soft rock. This paper describes rock physical and mechanical tests and field monitoring is employed to investigate the cause and development process of large deformation in Dongsong hydropower station in Sichuan Province, China. The results show that the free expansion rate of the rock sample is 20.0%, the average expansion stress of the rock sample is 11.0 kPa, and the expansibility of the rock is low. Large deformation of surrounding rock mainly comes from the dilatancy effect with high geostress and relaxation deformation with weak support. Shotcrete sealing exposed surrounding rock, and early strength support avoiding water immersion are useful to deal with the three main factors (weathering, water and confining pressure) that affect the strength of surrounding rocks. The second lining applied in time can effectively limit the further development of stress and deformation of initial support, and prevent the cracking and large deformation of concrete. Clearance convergence is suggested to be the main monitoring work in construction, because of its advantages of intuitive results, easy quality assurance of instrument installation and high accuracy. [ABSTRACT FROM AUTHOR]

The Wenchuan earthquake occurred in Sichuan Province, China, on May 12, 2008, and caused a large number of secondary geological disasters such as collapses, debris flows, and landslides, as well as extensive damage to local vegetation. The earthquake had an impact on the regional climate, seriously affecting the sustainable development of the regional environment and economy. In this study, the normalized difference vegetation index (NDVI) was used to characterize the vegetation status, which was calculated from images acquired by the MODIS sensor. Based on the vegetation cover and precipitation of the area affected by the Wenchuan earthquake over about 70 years, in this paper we analyze the characteristics of vegetation changes and their impact on the climate after the earthquake. The results revealed that the above secondary geological disasters caused by the earthquake destroyed vegetation. After the earthquake, NDVI decreased from 0.394 in 2007 to 0.383 on July 1, 2008, and then increased year by year to 0.413 in 2015, except in 2010. During the two years after the earthquake, several large-scale debris flows occurred in this area, damaging the surface vegetation, so the vegetation coverage was low in 2010. The change of the land cover has an indirect impact on the local precipitation. The annual and seasonal (except winter) precipitation trended downward from 1948 to 2018, with an annual average decrease of 1.6069 mm, but trended upward from 2008 to 2018, with an annual average increase of 14.012 mm, after the Wenchuan earthquake, indicating the recovery of vegetation. The increased vegetation promoted regional precipitation, but the interaction mechanism between the vegetation cover and the precipitation is complex. The effect of the vegetation differs in different regions and cannot be generalized. This study provides theoretical support for vegetation restoration and environmental management in areas with strong earthquakes. [ABSTRACT FROM AUTHOR]

In its one hundred years of existence, the Communist Party of China has experimented with how to connect its narratives of legitimacy to people's affects. In this essay, I trace the conceptualization of gratitude, from its repudiation in the Mao era as a vestige of feudalism and imperialism to its return in the reform era as a re-verticalization of Party sovereignty. The paper addresses four examples of gratitude work: Politburo Standing Committee member Wang Yang's short-lived critique of gratitude in the name of a different conception of popular sovereignty; the celebration of the tenth anniversary of the Sichuan earthquake as a day of gratitude; the detention of Uyghurs in Xinjiang who are taught to be grateful to the Communist Party in a campaign of religious de-radicalization; and the refusal of gratitude in quarantined Wuhan during the COVID-19 pandemic. In these cases, the Communist Party's sovereignty stands at the threshold between bio- and necro-politics, promising life and salvation in the midst of death and destruction. [ABSTRACT FROM AUTHOR]

Previous seismic damage reports have shown that the damage and collapse of buildings is the leading cause of fatality and property loss. To enhance the estimation accuracy of economic loss and fatality in seismic risk assessment, a high-resolution building exposure model is important. Previous studies in developing global and regional building exposure models usually use coarse administrative level (e.g., county, or sub-country level) census data as model inputs, which cannot fully reflect the spatial heterogeneity of buildings in large countries like China. To develop a high-resolution residential building stock model for mainland China, this paper uses finer urbanity level population and building-related statistics extracted from the records in Tabulation of the 2010 Population Census of the People's Republic of China (hereafter abbreviated as the "2010-census"). In the 2010-census records, for each province, the building-related statistics are categorized into three urbanity levels (urban, township, and rural). Statistics of each urbanity level are from areas with a similar development background but belong to different administrative prefectures and counties. Due to privacy protection-related issues, these urbanity level statistics are not geo-coded. Therefore, before disaggregating these statistics into high-resolution grid level, we need to determine the urbanity attributes of grids within each province. For this purpose, the geo-coded population density profile (with 1 km x 1 km resolution) developed in the 2015 Global Human Settlement Layer (GSHL) project is selected to divide the 31 provinces of mainland China into 1 km x 1 km grids. Then for each province, the grids are assigned with urban/township/rural attributes according to the population density in the 2015 GHSL profile. Next for each urbanity of each province, the urbanity level building-related statistics extracted from the 2010-census records can be disaggregated into the 2015 GHSL geo-coded grids, and the 2015 GHSL population in each grid is used as the disaggregation weight. Based on the four structure types (steel/reinforced-concrete, mixed, brick/wood, other) and five storey classes (1, 2-3, 4-6, 7-9, ≥ 10) of residential buildings classified in the 2010-census records, we reclassify the residential buildings into 17 building subtypes attached with both structure type and storey class and estimate their unit construction prices. Finally, we develop a geo-coded 1 km x 1 km resolution residential building exposure model for 31 provinces of mainland China. In each 1 km x 1 km grid, the floor areas of the 17 residential building subtypes and their replacement values are estimated. To evaluate the model performance, comparisons with the wealth capital stock values estimated in previous studies at the administrative prefecture-level and with the residential floor area statistics in the 2010-census at the administrative county/prefecture-level are conducted. The practicability of the modeled results in seismic risk assessment is also checked by estimating the seismic loss of residential buildings in Sichuan Province combined with the intensity map of the 2008 Wenchuan Ms8.0 earthquake and an empirical loss function developed from historical seismic damage information in China. Our estimated seismic loss range is close to that derived from field investigation reports. Limitations of this paper and future improvement directions are discussed. More importantly, the whole modeling process of this paper is fully reproducible, and all the modeled results are publicly accessible. Given that the building stock in China is changing rapidly, the results can be conveniently updated when new datasets are available. [ABSTRACT FROM AUTHOR]

Colluvium accumulation slopes (CAS) are widely distributed in Sichuan Province of China, especially in the regions with intense earthquake histories. These kinds of accumulations show obvious discontinuous and heterogeneous characteristics, to which the discrete element method (DEM) for discontinuous material is more suitably applied. Wenchuan earthquake with a magnitude of 8.0, caused a large number of debris flows or landslides in the colluvium formations, which are densely distributed in the quake-hit region in Sichuan province. The dynamic response of CAS is a key problem for study of stability of these kinds of slope. In this paper, PFC (Particle Flow Code) from Itasca based on DEM is used for modeling the dynamic response of the colluvium accumulations and some typical models were built according to the geological investigations carried out in the epicentral area. Horizontal shearing waveforms of WenChuan earthquake were input into the model for the study of the dynamic response of overlying colluvium accumulation and bedrock. The modeling results of different models under the same seismic conditions are described and analyzed at the end of the paper. [ABSTRACT FROM AUTHOR]

Analysis of the low frequency fluctuations of the magnetic and electric fields prior to a strong earthquake of magnitude 8.0 on 12 May 2008 in Sichuan Province is given. We analyse the disturbances of the ionospheric electromagnetic field prior to the earthquake starting 2 weeks before this event, but detailed analysis is given for 6 and 9 May, 6 and 3 days prior to the earthquake, when the observed effects were strongest. Special attention is given to the characteristics of the spectra of these variations and the search for nonlinear effects. This analysis is possible in the time intervals when the extra low frequency (ELF) waveform was transmitted. Although the mechanism of energy transmission from the earthquake preparation zone to the ionosphere is not determined, it can be said that the ionospheric plasma is an unstable medium and that even a small perturbation can lead to variations in the electromagnetic field and plasma parameters. Some attempts at this discussion are given in the paper. The observations by Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) and discussed in this paper suggest the presence of plasma turbulence over the area above the Wenchuan Earthquake on 12 May 2008. The characteristics of the observed disturbances are studied with wavelet and bispectral analysis, tools which are more relevant for analysing plasma turbulence. [ABSTRACT FROM AUTHOR]

The rapid and accurate detection of damaged buildings after an earthquake is critical for emergency response. As roof textures of damaged buildings are changed, damaged buildings may be accurately detected by the texture heterogeneity among buildings. However, existing researches have scarcely detected damaged buildings quantitatively by the texture heterogeneity among buildings from post-earthquake images. Therefore, this paper proposes an approach for the detection of earthquake-damaged buildings using texture feature contribution from post-earthquake images. In the proposed approach, a texture feature contribution index (TFCI) is defined by the information gain for selection of the optimal texture features, and a building texture damage index (TFdam) is defined for detection of damaged buildings. The proposed approach primarily comprises the following three steps: 1) building image objects are obtained using a pre-earthquake vector map to segment post-earthquake images; 2) the optimal texture features are selected by the TFCI to establish the texture feature vector; 3) damaged buildings are detected using the TFdam. The town of Leigu in Sichuan Province was selected as the study area to validate the performance of the proposed approach. The accuracy of 93.45% and kappa coefficient of 0.869 were achieved. Furthermore, the results indicate that the proposed approach can accurately detect earthquake-damaged buildings. [ABSTRACT FROM AUTHOR]

The MS8.0 earthquake that occurred in Wenchuan, Sichuan in 2008 provides an important case for the study of operational earthquake forecasting and short-term aftershock forecasting of major disaster-inducing earthquakes in China. This paper focuses on the comparative study of the applicability of the epidemic-type aftershock sequence (ETAS) model, the Reasenberg–Jones (R–J) model and the Omi–R–J model, which are widely adopted internationally for short-term aftershock forecasting and seismic hazard mitigation strategy research. We compare the stability of model parameters and aftershock occurrence rate forecasting, and evaluate the effectiveness of forecasting using the N-test and T-test with multiple time windows. The results show that the sequence parameters of the ETAS model, the R–J model and the Omi–R–J model tend to stabilize after 15.50, 15.50 and 6.00 days following the earthquake respectively, and the attenuation of the Wenchuan MS8.0 earthquake is rather normal. Compared to the ETAS model and the R–J model, the Omi–R–J model obtain steadier model parameters in a shorter time with significantly smaller parameters pORJ, cORJ, bORJ and standard deviations. Among the three models, the overall aftershock occurrence rate forecasted by the R–J model is the highest, followed by the Omi–R–J model, while that of the ETAS model is the lowest. N-test results show overall forecasting effectiveness of 93.8, 80.7 and 97.7% for the ETAS, R–J and Omi–R–J models, respectively, with the ETAS and Omi–R–J models superior to the R–J model, and the Omi–R–J model slightly better than the ETAS model. The overall "information gain per earthquake" calculation results show that the ETAS model is superior to the Omi–R–J and R–J models, while the Omi–R–J model is better than the R–J model; thus the combined use of the ETAS and Omi–R–J models by focusing on their respective strengths might ensure optimal performance. These "maneuverable" forecasting approaches to short-term aftershock model forecasting will play a vital role in efficient post-disaster relief, emergency management decision-making and post-disaster reconstruction. [ABSTRACT FROM AUTHOR]

The National Strong Motion Observation Network System (NSMONS) of China is briefly introduced in this paper. The NSMONS consists of permanent free-field stations, special observation arrays, mobile observatories and a network management system. During the Wenchuan Earthquake, over 1,400 components of acceleration records were obtained from 460 permanent free-field stations and three arrays for topographical effect and structural response observation in the network system from the main shock, and over 20,000 components of acceleration records from strong aftershocks occurred before August 1, 2008 were also obtained by permanent free-field stations of the NSMONS and 59 mobile instruments quickly deployed after the main shock. The strong motion recordings from the main shock and strong aftershocks are summarized in this paper. In the ground motion recordings, there are over 560 components with peak ground acceleration (PGA) over 10 Gal, the largest being 957.7 Gal. The largest PGA recorded during the aftershock exceeds 300 Gal. [ABSTRACT FROM AUTHOR]

A giant, high-position rockslide occurred in Xinmo village of Maoxian County, Sichuan, China, on June 24, 2017. It was the largest rockslide recorded since the 2008 Wenchuan earthquake, and caused great loss. We use field survey data and relevant information to describe the geometric and zoning of the Maoxian landslide, and we discuss its sliding mechanism and the role of active faults in its formation. The sliding mode of the Maoxian landslide involves a plane failure mechanism (sliding rupture), while the slipping process can be divided into two stages: a rock cracking and deterioration stage, and a high-speed sliding stage. The role of active faults (earthquake and fault movement) is probably the most important factor in the Maoxian landslide formation, while lithology played a catalytic role and rainfall acted as an inducing factor. The fault vertical combination model ("back thrust" dynamic model) proposed in this paper provides a reasonable explanation for the different distribution of the coseismic landslides caused by the 1933 M 7.5 Diexi earthquake. We consider that a steep slope near the active fault, especially where the active fault intersects, just like the "locked segment" of a fault, is the uppermost area to develop a large landslide. [ABSTRACT FROM AUTHOR]

Large squeezing deformation has always been a critical concern in the construction of deep-buried tunnels in soft-weak rock masses. This paper describes a case study on the large deformation mechanism and supporting method of the Maoxian tunnel in Sichuan Province, China, which is located in the core area influenced by the 2008 Wenchuan earthquake and suffered severe large deformation in broken phyllite under high geo-stress. Through a survey on the geological features, the deformation mechanism of surrounding rock and the failure characteristics of supporting structures of the Maoxian tunnel in F1 fault zone were studied. It was found that the occurrence of large deformation was due to the combined action of the high geo-stress and poor self-stability of carbonaceous phyllite. In order to control the squeezing deformation, single and double primary support methods were adopted in succession. A comparative field test was conducted to study their supporting mechanism and mechanical behavior in terms of surrounding rock pressure, internal stress of the steel arch, and axial force and bending moment of the secondary lining. The results revealed that the single primary support method cannot ensure the long-term safety of the tunnel, since many cracks in concrete occurred after about 180 days. The double primary support method, however, was able to control the large deformation and rheological effects of broken phyllite under high geo-stress effectively. [ABSTRACT FROM AUTHOR]

The earthquake and its secondary geological disasters have some long-term effects on vegetation recovery, and the spatiotemporal differentiation of vegetation coverage in earthquake-stricken areas are often not valued by researchers. Beichuan County in Sichuan Province is the worst-hit area during Wenchuan earthquake, tracking the vegetation coverage in this disaster area can provide feedback for post-earthquake ecological restoration. Based on remote sensing (RS) and Geographic information system (GIS), this paper relies on dimidiate pixel model (DPM) and vegetation coverage transfer matrix to explore the vegetation coverage of the earthquake worst-hit area. The results show that the overall level of vegetation coverage in Beichuan county is high, and earthquakes are dominant in the areas with high vegetation coverage. Besides, earthquake can do most severe damages to the areas with high vegetation coverage, followed by medium damage impacting to the areas with medium vegetation coverage, but the damage of other areas are relatively small. From 2007 to 2020, the average vegetation coverage in Beichuan County decreased from 0.835 in 2007 to 0.755 in 2008, then gradually recovered to 0.826 in 2020, experiencing a sharp decline and then a steady increase. The recovery of vegetation coverage is improved over time, but the spatiotemporal differences of the recovery process are obvious. Elevation has the largest driving force on vegetation coverage (q = 0.569, p less than 0.001), followed by temperature and rainfall; the interaction between factors has a significant increasement in the spatial differentiation of vegetation coverage, indicating that vegetation coverage is a combination result of multiple factors. The research findings can help construct the scientific management of the eco-environment in the disaster area, it can also help builda medium to long-term ecological restoration plan according to the variation in vegetation coverage. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to study the spatial and temporal distribution characteristics of low-temperature continuous rain disasters in rice during the heaving-heading stage in Sichuan province, in order to provide scientific basis for disaster prevention and reduction of low-temperature continuous rain disasters in rice at different growth stages in Sichuan province. 【Method】 According to the topographic and geomorphic types of Sichuan province, the rice planting regions were divided into six regions, namely, the marginal mountain region around the basin, the parallel range-valley region in the east of the basin, the hilly region in the south of the basin, the shallow hilly region in the middle of the basin, the flat hill region in the west of the basin and the mountainous region in the southwest of Sichuan. Based on the data of daily mean temperature, maximum temperature, minimum temperature, precipitation and sunshine duration of 21 agricultural meteorological stations in Sichuan province from 1961 to 2020, the spatial and temporal distribution characteristics of low-temperature continuous rain during the period of rice starting from heading to heading were analyzed by using statistical analysis method combined with evaluation indexes of low-temperature continuous rain. 【Result】 (i) The frequency of mild, moderate and severe cold damage of rice during booting and heading stage in Sichuan province was as follows: 0%-32.5%, 0%-44.8% and 0%-50.3%, and the large values were all in the southwest Mountain area of Sichuan. Although the occurrence frequency of mild and moderate cold damage was relatively low, the distribution area of mild cold damage was the widest, followed by moderate cold damage, and the distribution area of severe cold damage was the smallest, only in the southwest Mountain area of Sichuan. (ii) The frequency of mild, moderate and severe continuous rain disasters were 0.4%-3.8%, 0%-5.2% and 0%-0.5%, respectively. (iii) The frequency of low-temperature continuous rain disasters was 0%-9.1% from 1961 to 2020, 0%-9.1% from 1991 to 2000, and 0%-3.3% from 1961 to 1970. (iv) From 1961 to 2020, the frequency of low temperature cold damage and low temperature continuous rain disaster passed the significance test of 0.05 over time, showing a decreasing trend. The frequency of continuous rain disaster did not change significantly with time and did not pass the morphological significance test of 0.05. 【Conclusion】 The frequency of low-temperature continuous rain disaster was high in the mountainous area of southwest Sichuan. In Sichuan province, the continuous low temperature rain disaster of rice during booting and heading stage showed a decreasing trend in recent years, which was consistent with the results of the reduction of low temperature cold damage and continuous rain disaster under the background of climate warming. [ABSTRACT FROM AUTHOR]

An increasing demand for assessing the hazard of debris-flow accumulation areas is critical to risk management and policy implication for debris-flow hazard mitigation. In this paper, a framework for hazard assessment in debris flow-prone areas is proposed. Based on the hazard definition, debris-flow hazard is computed by its occurrence probability and disruptive intensity. Debris-flow occurrence probability is defined as a joint probability considering both hydrological and debris supply condition. Debris-flow disruptive intensity is introduced to express the inundated and impact damage of debris flow by the distribution of flow depth and velocity. The distribution is based on an extended geometric model of debris-flow fans, including the maximum length, width, and thickness (or flow depth) of debris-flow fans, and the channel outlet width. A hazard matrix, correlated to debris-flow occurrence probability and disruptive intensity, is used to map the hazard on debris-flow accumulation areas. The proposed procedure is applied to assess the debris-flow hazard on the accumulation area of Shuida gully, located in the Longchi town, Sichuan province of China. Finally, the article considers the effects of hazard maps. [ABSTRACT FROM AUTHOR]

This paper deals with the leafhopper genus Oncopsis (Macropsinae) from Sichuan Province of China, and describes and illustrates two new species, O. konkaensis sp. nov. from Minya Konka (Sichuan), and O. moxiensis sp. nov. from Moxi Town (Sichuan), and provides a key to males and a geographic distribution map for Oncopsis species from Sichuan. [ABSTRACT FROM AUTHOR]

Research in the field of earthquake prediction has a long history, but the inadequacies of traditional approaches to the study of seismic threats have become increasingly evident. Remote sensing and Earth observation technology, an emerging method that can rapidly capture information concerning anomalies associated with seismic activity across a wide geographic area, has for some time been believed to be the key to overcoming the bottleneck in earthquake prediction studies. However, a multi-parametric method appears to be the most promising approach for increasing the reliability and precision of short-term seismic hazard forecasting, and thermal infrared (TIR) anomalies are important earthquake precursors. While several studies have investigated the correlation among TIR anomalies identified by the robust satellite techniques (RSTs) methodology and single earthquakes, few studies have extracted TIR anomalies over a long period within a large study area. Moreover, statistical analyses are required to determine whether TIR anomalies are precursors to earthquakes. In this paper, RST data analysis and the Robust Estimator of TIR Anomalies (RETIRA) index were used to extract the TIR anomalies from 2002 to 2018 in the Sichuan region using Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) data, while the earthquake catalog was used to ascertain the correlation between TIR anomalies and earthquake occurrences. Most TIR anomalies corresponded to earthquakes, and statistical methods were used to verify the correlation between the extracted TIR anomalies and earthquakes. This is the first time that the ability to predict earthquakes has been evaluated based on the positive predictive value (PPV), false discovery rate (FDR), true-positive rate (TPR), and false-negative rate (FNR). The statistical results indicate that the prediction potential of RSTs with use of MODIS is limited with regard to the Sichuan region. [ABSTRACT FROM AUTHOR]

While much of the scholarly work on the development of non-governmental organizations (NGOs) in China focuses on their relations with the state, this paper adopts an anthropological approach to explore previously understudied peasant–NGO relations through the lens of a village-level post-earthquake recovery project in Sichuan. The findings highlight three main types of gaps between the NGO and local villagers: the gaps between the villagers’ immediate needs and the NGO's long-term development plan; the gaps between the villagers’ pragmatic concerns and the “building a new socialist countryside” campaign; and the gaps between the private and collective economies. In spite of the project's unsatisfactory outcome, the NGO did not consider the project a failure. We argue that these gaps were, to a great extent, attributable to the continuing development of the institutional values of NGOs, which guide the transition of Chinese NGOs from traditional charities to modern philanthropic organizations. [ABSTRACT FROM PUBLISHER]

On 5 September 2022 (BJT), Luding, located in southwestern Sichuan Province, China, experienced an MS 6.8 earthquake. This earthquake occurred within the historical rupture zone of the 1786 MS 7.75 event, part of the southern section of the Xianshui He Fault belt. Given the average 155-year recurrence interval for strong earthquakes in this area, the 236 years since the last event made this earthquake somewhat expected. However, prior to this event, we did not detect any anomalies indicating low surface b-values, which are often indicative of a high-stress state in the source area before strong earthquakes, as highlighted by numerous studies. Our research focused on the northern section of the eastern boundary of the Sichuan–Yunnan sub-block, encompassing the Xianshui He, Anning He, Zemu He, and Daliang Shan fault belts. We meticulously located earthquakes of ML ≥ 1.5 from 2009 to May 2022. The catalog was divided into two periods: 2009–2014 and 2015–May 2022. Using an AIC-constraint method, we analyzed the changes in b-values (Δb) in the latter period compared to the former. Our findings revealed a significant abnormal Δb zone (Δb < −0.3), with a radius of approximately 50 km, when ΔAIC ≥ 2 was selected. Intriguingly, the epicenter of the recent Luding MS 6.8 earthquake fell within this abnormal zone. Furthermore, we calculated the b-value cross-section for the southern section of the Xianshui He fault belt using a directory of precisely located small earthquakes. This revealed that the location, scale, and shape of the abnormally low-b-value area corresponded with the large displacement co-seismic area of the main earthquake, affirming the b-value's effectiveness in identifying asperities. The b-value's temporal evolution prior to the mainshock exhibited a nearly decade-long continuous decrease, signifying a long-term stress-loading process akin to that observed before many strong earthquakes. The b-value anomalies observed from different profiles before the Luding earthquake underline the necessity of a comprehensive, multi-dimensional analysis of such anomalies. Finally, our analysis indicates that nine earthquakes with MS ≥ 6.5, including the Luding MS 6.8 event, have contributed to increased Coulomb Failure Stress change (ΔCFS) in the Daofu (DF)–Kangding (KD) section of the Xianshui He fault belt and the northern section of the Anning He fault belt south of Shimian (SM), with amplitudes surpassing the 0.01 MPa threshold. This suggests the potential for strong earthquakes in these zones. [ABSTRACT FROM AUTHOR]

The development of machine learning technology enables more robust real-time earthquake monitoring through automated implementations. However, the application of machine learning to earthquake location problems faces challenges in regions with limited available training data. To address the issues of sparse event distribution and inaccurate ground truth in historical seismic datasets, we expand the training dataset by using a large number of synthetic envelopes that closely resemble real data and build an earthquake location model named ENVloc. We propose an envelope-based machine learning workflow for simultaneously determining earthquake location and origin time. The method eliminates the need for phase picking and avoids the accumulation of location errors resulting from inaccurate picking results. In practical application, ENVloc is applied to several data intercepted at different starting points. We take the starting point of the time window corresponding to the highest prediction probability value as the origin time and save the predicted result as the earthquake location. We apply ENVloc to observed data acquired in the southern Sichuan Basin, China, between September 2018 and March 2019. The results show that the average difference with the catalog in latitude, longitude, depth, and origin time is 0.02°, 0.02°, 2 km, and 1.25 s, respectively. These suggest that our envelope-based method provides an efficient and robust way to locate earthquakes without phase picking, and can be used in earthquake monitoring in near-real time. [ABSTRACT FROM AUTHOR]

From 12 to 14 August 2010, heavy rainstorms occurred in the Sichuan province in SW China in areas which were affected by the 2008 Wenchuan Earthquake, inducing catastrophic debris flows. This disaster is named as "the 8.13 debris flows". The results of the research presented in this paper show that the 8.13 debris flows are characterized by a simultaneous occurrence, rapid-onsets, destructive impacts, and disaster chain effects. They are located along the seismic fault, because the source materials mainly originate from loose deposits of landslides which were triggered by the Wenchuan Earthquake. The presence of large amounts of these loose materials on the slopes and the development of high intensity rainfall events are the main causes for the formation of these debris flows. The study of the 8.13 debris flows can provide a benchmark for the analysis of the long-term evolution of these debris flows in order to make proper engineering decisions. A flexible drainage system is proposed in this paper as a preventive measure to mitigate the increasing activity of these debris flows in the earthquake-affected area. [ABSTRACT FROM AUTHOR]

This paper documents the emergency breaching of an approximately 110-m-high landslide dam that was created at Tangjiashan during the 2008 Wenchuan earthquake of China's Southwest Sichuan Province. As an emergency measure, a 13-m-deep channel was excavated to reduce the volume and head of the released water during the dam breaching and to create a controlled flood that was intended to prevent catastrophic consequence for 1.2 million people downstream. From detailed monitoring and survey works carried out during and after the dam break it was found that (1) the breaching initiated at a pool water level of 742.1 m with an estimated flow velocity of 2.4 m/s, and virtually terminated at a pool water level of 720.3 m with an estimated velocity of 2.5 m/s, which can be regarded as the incipient velocity that initiated erosions for the soils at this particular site; (2) a controlled flood released 167×106-m3 reservoir water with a peak flow rate of 6,500 m3/s, during which a maximum velocity of about 5.0 m/s was measured; (3) in 12 h, the channel bed was eroded 30 m down and the sidewall was enlarged 145 m wide at an elevation of 719 m, which was expanded to 200-350 m at the top of the channel due to subsequent landslips of the temporary slopes; and (4) the measured data indicated an incipient velocity that initiated soil erosions, which is found to be conceptually in general agreement with the existing approaches of this threshold value. [ABSTRACT FROM AUTHOR]

The Satellite Differential Interferometric Synthetic Aperture Radar (DInSAR) has already demonstrated its potential to map co-, post- and inter-seismic deformation. This paper presents an.alysis of the surface-displacement field of the 12 May 2008 magnitude 8.0 Wenchuan Earthquake using the Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) DInSAR. Six PALSAR interferograms of paths 471 to 476 are generated. A new approach, which uses the information of overlapping interferograms, has been developed to compensate for orbit error. The main advantage of this approach is that the calculation is performed without the need for phase unwrapping. Once the orbit error has been compensated for, the interferograms are then merged to form a single interferogram. The final mosaic of interferograms demonstrates a much more consistent co-seismic surface-displacement field than the original interferograms. [ABSTRACT FROM AUTHOR]

In this paper, the total electron content (TEC) of Global Ionosphere Maps (GIMs) is normalized and employed to study the seismo-ionospheric anomalies at the time of the 12 May 2008 M 8.0 Wenchuan Earthquake. The space weather conditions are taken into account. It is found that remarkable reductions appear locally around the epicentre and their conjugate points during the daytime of 29 April and 6-10 May 2008. A global study and a strict criterion are applied to detect anomalies. Results show that the anomalies on 29 April and 6 and 7 May 2008, which are respectively days 13, 6 and 5 before, are possibly related to the earthquake. The conjugate signature implies the seismo-generated electric field is essential. [ABSTRACT FROM AUTHOR]

The Lushan earthquake with magnitude M 7.0 ( M 6.6, USGS) in Sichuan Province, China, triggered a large number of landslides, which seriously aggravated the earthquake's destructive consequences. This paper mainly focuses on the methodology of the urgent landslide susceptibility assessment right after the earthquake. The detailed landslide inventory (including 5,688 landslides) is prepared by means of urgent post-earthquake landslide field survey, landslide remote sensing interpretation of multi-source remote sensing images including high-resolution unmanned aerial vehicle images and historical landslide archives. Ten remarkable causative factors for landslide occurrence have been selected to conduct the landslide susceptibility assessment, including earthquake intensity, landslide density and slope gradient. An integration assessment approach is developed to facilitate the effective urgent post-earthquake landslide susceptibility assessment using three methods: factor sensitivity analysis, analytical hierarchy process and factor-weighted overlay. Such integration can effectively reduce the subjectivity and uncertainty resulting from using single method. The validation evaluation using the area under curve suggests the landslide susceptibility assessment results have satisfactory accuracy, and the suggested methodology is effective for the urgent post-earthquake landslide susceptibility assessment. The study results reveal that earthquake intensity and slope gradient are the two most important causative factors for post-earthquake landslide occurrence in the Lushan earthquake-impacted area. The dominant slope gradient and slope aspect with relatively higher landslide frequency are 45°-50° and south-east direction, respectively. The intense earthquake impact increased the dominant slope gradient of landslide spatial distribution, and the thrust campaign of seismogenic fault with strike NE-SW made south-east direction as the dominant slope aspect of the landslide spatial distribution. The locations with very high and high landslide susceptibility are mainly distributed in the regions with higher earthquake intensity and adverse terrain conditions, such as Shuangshi town and Longmen town of Lushan county and Muping town of Baoxing county. The study results are expected to provide a beneficial reference for the landslide prevention and infrastructure reconstruction after the Lushan earthquake. [ABSTRACT FROM AUTHOR]

During the five rainy seasons following the 2008 Wenchuan earthquake, at least eight catastrophic events of multiple debris flows occurred in the Yinchanggou area of Baishui River basin, in southwestern China. The deposits had some serious impacts on the transportation, communication, and reconstruction activities. It indicates the start of a period with a high-frequency debris flow activities. In this paper, a detailed review is made of the latest 12 debris flow events, which occurred on 18th August 2012. Field reconnaissance and measurements, supported by a remote sensing interpretation, were conducted to reveal the locations and morphological characteristics of debris flow catchments. A total volume of 50.26 million m co-seismic landslides, triggered by the Wenchuan earthquake, served as source materials for these debris flows and/or shallow landslides. Bedrocks, which were on the hanging wall of the Yingxiu-Beichuan Fault with a mean slope gradient larger than 30°, were the most susceptible for these seism-triggered failures. The volume of debris flow deposits on individual fans vary by many orders of magnitude from 2,900 to 223,500 m. The huge amount of reserves of source material compared to debris flow volumes currently deposited and taking into account the relatively low morphology index values form an indication of the early stage in the development of debris flows and the immense potential for debris flow occurrence in the future. There are two patterns of debris flow initiation which can be distinguished in this study: (a) the channel initiation pattern of concentrated overland flow erosion in the channel beds and (b) the slope initiation pattern which shows the development of new landslides and a transition into debris flows during a heavy rainfall. A catastrophic debris flow in the Haihuiqiao watershed of the Yinchanggou area was selected to show in detail the mechanism of debris flow initiation as a result of intensive erosion in loose debris materials. The critical rainfall threshold in terms of daily precipitation decreased by 77 % compared to the pre-earthquake threshold. A primary rainfall intensity-duration ( ID) threshold curve was constructed for debris flows for an early-warning system and compared with other global rainfall thresholds. The discussion is focused on the initiation mechanisms of debris flows and the assessment of the critical meteorological threshold. [ABSTRACT FROM AUTHOR]

This paper summarizes the Ms 6.0 earthquake disaster that occurred in Changning, Sichuan Province, China, on 17 June 2019. Additionally, a description of the disaster emergency response is provided. As determined by on-site investigation and analysis, the direct causes of earthquake casualties are summarized. Among them, 66 % of the casualties can be attributed to substandard seismic protection, 25 % to improper earthquake risk avoidance, 6 % to earthquake-induced geological disasters, and 3 % to pre-existing diseases exacerbated by the earthquake. Responding to the causes of these four casualty types, we summarize 4 lessons, which are to build in accordance with seismic protection requirements; strengthen publicity and education awareness of earthquake emergency evacuation and training for the population; investigate and evaluate potential geological disaster sources in the stricken area, along with conducting prevention and control; establish cooperation with health organizations, focusing on people who are older or have serious illnesses and conducting earthquake evacuation training and psychological counselling. [ABSTRACT FROM AUTHOR]

The increased seismic activity of the last ~10 years in Changning county of Sichuan Province comprised just small (mostly ML < 5.0) injection‐induced earthquakes. The MW 5.7 earthquake on June 17, 2019, is the largest event ever reported there. Moment tensor of the mainshock was remarkably dominated by a compensated linear vector dipole. We resolve its fine structure showing it was a doublet, allowing approximation by a thrust‐ and strike‐slip subevent. The mainshock nucleated as thrust faulting, which (together with the largest aftershocks) can be linked with previously known reverse faults, favorably oriented to regional stress field. Contrarily, the strike‐slip segment of the mainshock, less favorably oriented, was probably facilitated by elevated pore pressure due to previous injections. Shallow active strike‐slip faulting, not yet mapped in the region, is a new feature, important for future hazard assessment. Plain Language Summary: Changning county in Sichuan Basin belongs to major salt‐producing resources, with water injection wells drilled to ~3‐km depths. Enhanced occurrence of small earthquakes was observed in the last ~10 years. However, on June 17, 2019, a damaging earthquake struck the region. Seismic agencies reported diverse focal mechanisms and pointed to departures from shear faulting, typical for tectonic events. To understand these enigmatic features, we modeled records from 12 broadband seismic stations, adding over 100 first‐motion polarities. We found that the earthquake was very shallow (~4 km) and consisted of two shear events: the initial thrust faulting and the following strike‐slip faulting along an SE‐NW trending near‐vertical plane, aligned with aftershocks. The initial episode was "normal," expected on existing faults and supported by tectonic stresses of the region. Contrarily, the significant strike‐slip faulting appears to be rather "abnormal," probably facilitated by the initial shock and by elevated pressure of underground fluids. The 2019 earthquake provided a rare opportunity to illuminate interplay between long‐lasting water injections, tectonic stress, complexity of existing faults, and their dynamic interactions. That is how seismology aims at making industrial activities sustainable and safe. Key Points: This is the so‐far largest earthquake in a salt‐mining area where seismicity has been increased in previous 10 years by injection‐induced eventsMainshock nucleated as a thrust, then rupturing a previously unknown strike‐slip fault, suboptimally oriented to regional stress fieldThe complex nature of the event explains its small double‐couple component and diversity of focal mechanisms across reporting agencies [ABSTRACT FROM AUTHOR]

Based on a satellite retrieval methodology, the cloud microphysical properties of two airborne cloud seeding operations in Sichuan Basin of Southwest China are analyzed in this paper. The methodology for the retrieval of the cloud particle effective radius (Re), cloud temperature (T) and microphysical structure is based on the data from the AGRI onboard the Chinese FY-4A satellite. A microphysical red–green–blue (RGB) composite visualization has been devised to qualitatively highlight the cloud composition. This RGB scheme is displayed by compositing visible 0.65 micron channel, near infrared 2.2 micron channel and infrared 11.0 micron channel. And the vertical structure and development status of the clouds are demonstrated by the T-Re profiles. The results show that after the cloud seeding operation on June 11, 2018, the cloud particle effective radius increases, and the ground observed PM10 and PM2.5 pollutants decrease as well. As for the cloud seeding operation on November, 17, 2018, the satellite inversion shows that the medium and low level clouds are rich in super-cooled water with small cloud particle effective radius. After the cloud seeding operation, the effective radius of the cloud droplets increases significantly. Both of these two cloud seeding operation in Sichuan Basin demonstrate obvious precipitation enhancement results in the seeding impact area. [ABSTRACT FROM AUTHOR]

Buildings' energy resilience in natural disasters is reliant on the support of the functionalities of critical infrastructure that the buildings connect to, such as highway-bridge and electric power systems. Meanwhile, as critical infrastructure systems have increasingly become interconnected and interdependent, they are more susceptible to natural hazards and less able to withstand their effects. Insufficient research has been conducted regarding computational models of effectively representing the interdependencies and interactions involved in the restoration scheduling of post-disaster critical infrastructure systems. To address this research gap, this study proposes integer programs, integrating hybrid genetic algorithms, to explicitly investigate the impact of interactions and interdependencies between electric power systems (EPSs) and highway-bridge systems (HBSs) on the energy-recovery processes of buildings. The objective is to dynamically prioritize the restoration scheduling for EPSs and HBSs while considering inspection and restoration activities. A case study based on the 2008 Wenchuan Earthquake in Sichuan province, China, is employed to validate the efficacy of the proposed method. The results of the analysis reveal that the dynamic model exhibits a substantial 6.4% improvement in building energy resilience at the seven-day mark, compared to the static model. Moreover, the proposed coupled EPS–HBS inspection–restoration joint model outperforms a disjoint EPS inspection–restoration scheduling model, yielding a remarkable 11.4% enhancement in system resilience at the seven-day mark. These findings underscore the significance of considering interdependencies and interactions within critical infrastructure systems to enhance the energy resilience of buildings in earthquake-affected areas. [ABSTRACT FROM AUTHOR]

The central-southern part of the eastern border of the Sichuan-Yunnan rhombic block provides the research strategy of 'trade space for time' with an interesting fault system, where the segments have similar focal mechanisms and cover almost continuous spectra of elapse rates. We experiment to study the seismological characteristics of different segments with different elapse rates. We employed the de-clustered earthquake catalog for the calculation of b values for each segment. The analysis revealed that different segments have similar b values, which implies that, although different segments have different periods of earthquake recurrence, the 'natural time' for the whole fault system elapses with a homogeneous pace. We extended the earthquake potential score (EPS) for nowcasting earthquakes to a quasi-EPS (qEPS). It is found that qEPS increases with the increase of elapse rates, albeit for those fault segments whose elapse rates have exceeded 1, qEPS may better reflect the seismic hazard. [ABSTRACT FROM AUTHOR]

The Longchi area with the city of Dujiangyan, in the Sichuan province of China, is composed of Permian stone and diorites and Triassic sandstones and mudstones intercalated with slates. An abundance of loose co-seismic materials were present on the slopes after the May 12, 2008 Wenchuan earthquake, which in later years served as source material for rainfall-induced debris flows or shallow landslides. A total of 48 debris flows, all triggered by heavy rainfall on 13th August 2010, are described in this paper. Field investigation, supported by remote sensing image interpretation, was conducted to interpret the co-seismic landslides in the debris flow gullies. Specific characteristics of the study area such as slope, aspect, elevation, channel gradient, lithology, and gully density were selected for the evaluation of debris flow susceptibility. A score was given to all the debris flow gullies based on the probability of debris flow occurrence for the selected factors. In order to get the contribution of the different factors, principal component analyses were applied. A comprehensive score was obtained for the 48 debris flow gullies which enabled us to make a susceptibility map for debris flows with three classes. Twenty-two gullies have a high susceptibility, twenty gullies show a moderate susceptibility and six gullies have a low susceptibility for debris flows. [ABSTRACT FROM AUTHOR]

On May 12, 2008, an Ms 8.0 earthquake occurred on the Longmen Mountain Fault in Wenchuan County, Sichuan Province, China. Based on the reported earthquake intensity and surface displacement distributions in the affected areas, the damages to buildings in high-intensity areas were investigated. This paper focused on the buildings in Yingxiu Town, Wenchuan County. The unreasonable structural design and structural type were found to be the main reason for the damages of buildings. The geological environment problems of the residential area were also discussed. This research would provide valuable reference for scientific earthquake-resistance design and reconstruction after earthquake disaster. [ABSTRACT FROM AUTHOR]

During the 12 May 2008 Wenchuan earthquake, a large landslide of approximately 30 million m³ occurred at Donghekou with a particle run-out distance of over 2000 m. This paper presents fascinating particle flow and segregation characteristics in the landslide process found through field investigation of changes in the soil particle size, density, and fabric along the particle movement paths. The soil particles experienced projection, long-distance flying, sliding, and rolling. Trajectory segregation, inverse grading, and particle crushing were found in the landslide event, which contributed to the heterogeneity of the soil deposits. In the initial deposition area, particles with larger diameters appeared to have flown longer. Materials from different sources mixed, forming more uniform debris. In the run-out area, the particle flow tended to cause large particles to travel further. However, particle disintegration and crushing led to more small particles along the movement paths and the observed characteristic flow distances of very large particles did not increase with the particle diameter, which is different from observations of an idealized granular mass flow. [ABSTRACT FROM AUTHOR]

This paper argues that negotiation and accommodation between the state and the media, with the latter having gained more bargaining power, should be considered in assessing the transformation of the Chinese media. It examines the discourses of media professionals on the coverage of the 2008 Sichuan Earthquake to reveal how they seized the opportunity presented by the well-received breakthrough in the coverage of the earthquake to bargain with the state for more autonomy. The purpose of the examination is three-fold. First, what drove the Chinese state media such as CCTV to risk breaking regulations? Secondly, how did the Central Government respond to the media-led breakthrough? Answers to these questions prepare the ground for the final one, and that is, how do media professionals bargain with the state for more autonomy? [ABSTRACT FROM AUTHOR]

Radar satellite imagery was valuable in supporting extensive rescue operations after the Wenchuan Earthquake on 12 May 2008 due to its ability to operate independently of weather conditions, day and night. However, it is a challenging task to identify damaged or destroyed buildings using synthetic aperture radar (SAR) data. The standard procedure for identifying damaged buildings is to use change detection by comparing post-seismic to pre-seismic images, but almost no archived high-resolution SAR images were available of the rather remote area damaged by the Wenchuan Earthquake. Building-damage assessment using only post-event SAR images was therefore necessary to assess the areas of damage. In this paper, theoretical assumptions about the appearance of collapsed buildings in high-resolution SAR images were drawn and verified with visual feature interpretations of real SAR images from the area. [ABSTRACT FROM AUTHOR]

The availability of commercial very high resolution (VHR) satellite imagery makes it possible to detect and assess building damage in the aftermath of earthquake disasters using these data. Although conventional change detection methods may be used to assess the building damage, the analysis is directed to all classes, both damaged and undamaged, but is not focused on the class of interest. In this paper, we proposed to detect the building damage in urban environments from multitemporal VHR image data using the One-Class Support Vector Machine (OCSVM), a recently developed one-class classifier, which requires training samples from the building damage only. This was illustrated with building damage detection in an urban environment from multitemporal Quickbird images. The detection was conducted at pixel level and object level. Different input vectors for the OCSVM classifier were tested in order to assess the discrimination power of spectral and spatial features: pixel level spectral features and texture features, as well as object-based features. The results showed that the OCSVM performed better on the object level, with an overall accuracy of 82.33% and a kappa coefficient of 60.09%. The results also showed that the OCSVM provides a useful framework that can combine different features and focus on the building damage class of interest. More spatial features are needed to be exploited to obtain more accurate detection results in future studies. [ABSTRACT FROM AUTHOR]

This paper illustrates the capabilities of the Advanced Land Observing Satellite (ALOS) Phased Array Type L-band Synthetic Aperture Radar (PALSAR) instrument in the identification of macro- and meso-scale land deformation caused by the Wenchuan Earthquake of 12 May 2008. The specific location analysed is an area near the south west termination of the rupture zone where fault slip and surface deformations were relatively low and topography is relatively high. A full geometric processing of the interferometric synthetic aperature radar (InSAR) data is performed, including the removal of the stereoscopic effect, and the terrain effect fully compensated by identification and removal of layover and shadow areas. This allows for the full characterization of the main earthquake deformation. [ABSTRACT FROM AUTHOR]

This paper assesses the probability of the main stream in the Dujiangyan-Wenchuan reach of the Minjiang River becoming blocked by debris flows in response to the Wenchuan Earthquake of 12 May 2008, on the basis of analyses of remote sensing data and ground investigations. Background information of debris flow gullies was developed from field investigations and high-resolution remote sensing image interpretation, and was used to estimate the maximum discharge per unit width by means of the revised model of debris flow magnitude according to the situation after the Earthquake. Based on improved discrimination equations of river blocking induced by debris flow, 29 debris flow gullies were evaluated and classified as four probability levels: extreme high, high, moderate and low. The results show that most of the debris flow gullies were at or over moderate hazard level, accounting for 72.4% of the total area. The present results provide a scientific basis for the prevention, elusion and mitigation of debris flow hazards and will contribute to the reconstruction of an earthquake prone area. [ABSTRACT FROM AUTHOR]