Hazard Level Research Articles

Vulnerability and risk analysis of climate change Impacts on rice production (Oryza sativa L.) in Majalengka regency

Climate change, especially temperature and rainfall shifting can be a threat to the agricultural sector, i.e., the decrease in rice yields in Majalengka Regency as the West Java rice production center. As an anticipatory measure to deal with that problem, a study is needed regarding the level of hazard, vulnerability and risk of climate change impacts in Majalengka Regency. This research aims to identify climate change and examine the level of hazzard, vulnerability and risk of the impact of climate change on rice production in each sub-district in Majalengka Regency. The method used in this research is descriptive quantitative. The data used in the analysis of the level of hazard, vulnerability and risk of climate change include temperature, rainfall, production, productivity, planting area, harvested area and farmers' socio-economic data obtained from Statistics Indonesia; Meteorology, Climatology, and Geophysical Agency; Agriculture Office of Majalengka Regency and other relevant sources, while farmer interview data were used in analyzing strategic adaptation options. The results of the study stated that areas with a very high potential risk of decreasing rice production (Risk Index or RI > 0.80) were in Kertajati District; the risk level of rice production in the high category (RI 0.61-0.80) was in Bantarujeg and Ligung Districts. Meanwhile, areas with a very high level of risk of decreasing rice productivity (IR) > 0.80) are in Bantarujeg District; high-risk level (IR 0.61-0.80) was in the Districts of Lemahsugih, Malausma, Argapura, Kertajati, Jatipuh and Ligung. The adaptation efforts that can be made to reduce the risk of decreasing rice production are the use of superior seeds, crop rotation, intermittent irrigation systems, acceleration of land preparation by mechanization, application of the jajar legowo cropping system, and integrated pest management measures.

Probabilistic seismic hazard analysis for the Dominican Republic

The Dominican Republic experiences moderate to high seismic hazard mostly caused by oblique convergence at the Caribbean/North American plate boundary that manifests as subduction zones, less-pronounced subduction-like trenches with thrust faulting, long strike-slip faults parallel to the plate boundary, and onshore deformation. Historical earthquakes have damaged the Dominican Republic’s large cities and those in neighboring Haiti, once requiring relocation. Given this, the Dominican Republic joined the “Training and Communication for Earthquake Risk Assessment” (TREQ) project funded by the United States Agency for International Development, which aimed to increase earthquake risk assessment capacity in Latin American cities. The TREQ project was the basis for developing an openly available probabilistic seismic hazard model for the Dominican Republic. The input model was developed from two main datasets: a homogenized earthquake catalog and an active faults database that combines results of recent local projects with a global database. The seismic source characterization used these to constrain source geometries and occurrence rates for active shallow crustal earthquakes, subduction interfaces and subduction-like thrusts, and intraslab earthquakes. Shallow crustal earthquakes, including those on subduction-like thrusts, are modeled by smoothed seismicity and fault sources, the latter using pre-defined geometries that permit multi-fault ruptures. Seismicity on the Puerto Rico Trench subduction interface is modeled as a fault source, while intraslab sources use pre-defined gridded ruptures inside the intraslab volume. The source characterization applies epistemic uncertainties to modeling assumptions affecting occurrence rates and maximum magnitudes. The ground motion characterization used residual analyses from past regional projects as a basis, updating some components with more recent ground motion models. Computed hazard results reinforce those from recent studies in terms of geographical hazard patterns and levels. For 475-year return periods, peak ground acceleration (PGA) in Santiago de los Caballeros reaches 0.50 g, controlled by the Septentrional Fault, while all tectonic region types contribute to the PGA 0.31 g computed for Santo Domingo.

Nonlinear modeling and time-history analysis of dry-assembled precast concrete frames with buckling-restrained braces

A combination of dry-assembled precast concrete frames and buckling-restrained braces (BRB) is a viable choice for achieving the full potential of building industrialization and promoting the popularization of precast structures in earthquake-prone zones. A recent study has tested the seismic performances of a dry-assembled precast concrete frame with BRBs (BRB-DPCFs) under cyclic quasi-static loading. To study the comparative seismic behaviors of BRB-DPCFs and the monolithic concrete frames with BRBs (BRB-MCFs) under ground motion records, buildings between 3 and 12 stories in height were designed based on GB50010-2016, Chinese code for design of concrete structures, and investigated numerically. This investigation includes two-dimensional nonlinear time-history analyses of BRB-MCFs and BRB-DPCFs under two seismic hazard levels. BRB-DPCF demonstrated a larger maximum story drift compared to BRB-MCF, while the maximum residual story drift of the former is negligible in comparison to the latter at a higher building height or under a higher seismic intensity. The two systems show similar drift concentration factors, which was observed irrespective of the hazard level and the specific height of the building.

Microplastics contamination and risk assessment in bivalves of economic importance from Beypore estuary, Southern India

Microplastics (MPs) are ubiquitous pollutant causing severe threat to the biotic and abiotic components of the coastal ecosystem. Accumulation of MPs in the commercially important bivalves Viz. Perna viridis (green mussel) and Meretrix casta (clam) collected from four different locations of Beypore estuary, Southern India was studied. The study focused on the accumulation, characteristics, diversity indices, and human health risk assessment of MPs in the bivalves of Beypore estuary. A total of 120 bivalve samples were examined for the MPs contamination. Whole tissue digestion method using 10% KOH was employed to retrieve the MP content. The results indicate that the average abundance of MPs in Perna viridis is 2.38 ± 1.56 MPs/individual and 0.15 ± 0.09 MP/g/wet weight whereas, for Meretrix casta it is 1.35 ± 1.02 MPs/individual and 0.3 ± 0.27 MP/g/wet weight. Spearman's correlation reveals that there is no significant correlation observed between the abundance of MPs in the bivalves with their morphomertric parameters. The characteristics of MPs in the bivalves are dominated by translucent colored particles (88.95%) in the form of films (45.13%) and fibers (33.6%) having a size ranged between 300 and 1000 μm (51.13%) and composed of polyethylene (54.5%) and polypropylene (20%) polymers. The microplastic index in Meretrix casta ranged between 0.02 and 0.07 whereas for Perna viridis it ranged between 0.08 and 0.10 indicating minimal to moderate MPs contamination. The microplastics diversity integrated index ranged between 0.67 and 0.69 for Meretrix casta whereas, for Perna viridis the value ranged between 0.34 and 0.60 suggests moderate diversity of MPs derived from multiple sources. Based on polymer hazard index, the potential health risk was assessed with a hazard level ranged between II and IV suggesting significant health risk. Systematic monitoring of MPs at river basin scale along with stringent plastic waste management is required to minimize plastic pollution load into the river system.

Triple network hydrogel-based structure triboelectric nanogenerator for human motion detection and structural health monitoring

In this study, we developed a high-performance triple network (TN) PVA/PAAM/PEDOT/Zn2+ (PMPZ) hydrogel with exceptional mechanical properties and stable output performance. The robust and highly tough TN structure, fabricated via a Zn2+ pinned hydrogel and multi-network interpenetrating polymerization process, demonstrates high mechanical strength alongside exceptional mechanical properties. The PMPZ hydrogels exhibit notable mechanical sensing capabilities (gauge factor: 48.6) while maintaining excellent tensile (83.79 KPa) and compressive (96 MPa) strengths. As a triboelectric nanogenerator (TENG), the PMPZ-TENG shows outstanding flexibility and integrability, achieving a maximum open-circuit voltage (Voc) of 326.89 V and a peak power density of 368.3 μW/cm² with a load resistance of 10E8 Ω. Furthermore, the PMPZ-TENG demonstrates enduring practicality and responsiveness as a self-powered sensor. These properties make the PMPZ-TENG highly suitable for applications in human health monitoring. Additionally, we conducted computational simulations on the hydrogel and seismic-resistant civil models. 48 prototype structures simulated different seismic hazard levels to effectively capture plastic hinge deformation within high-strength steel composite K-shaped eccentric braced steel frames. The plastic hinge deformations informed the establishment of physical seismic models for structural health monitoring (SHM). This study not only introduces a high-performance PMPZ-TENG meeting practical requirements but also establishes a novel pathway for integrating TENGs in SHM.

Is Ocular Safety in Orthopaedics Overlooked? A Systematic Review of Annual Ocular Radiation Exposure and Protective Measures.

Intraoperative fluoroscopy is increasingly common in orthopaedics, although recent guidelines have reduced the maximum recommended exposure to 20 mSv annually. A systematic review of the literature was conducted to comprehensively assess current adherence to exposure guidelines, identify practice settings at increased risk for exposure, and determine the best practices and personal protective equipment for ocular radiation risk mitigation. In this systematic review we asked: (1) Is the annual amount of eye irradiation received by orthopaedic surgeons below the recommended limit of 20 mSv? (2) What is the effectiveness of leaded glasses in reducing the eye's exposure to radiation? (3) Which imaging setups and operative techniques reduce ocular irradiation? PubMed, Medline, EBSCOhost, and Google Scholar were queried on September 28, 2023, to identify studies assessing intraoperative ocular radiation exposure among orthopaedic surgeons. Studies that measured radiation in or around the eye (such as the bridge of the nose or eyebrows) during orthopaedic procedures were included. Exclusion criteria were duplicate studies, studies that only estimated eye radiation based on the radiation dose recorded at parts of the body distant from the eyes, nonoriginal research, case reports, and articles without full-text English versions available. A total of 393 unique articles were retrieved, and after title, abstract, and full-text screening, 23 dosimetry studies were included, comprising 12 prospective observational studies, 7 phantom models, 1 cadaver model, 2 observational studies, and 1 randomized control trial. Risk of bias was determined via the Methodological Index for Nonrandomized Studies (MINORS) tool. Study quality was generally good to excellent, with noncomparative studies having a mean MINORS score of 14 ± 0 of 16 and comparative studies achieving a mean score of 19 ± 1 of 24, with higher scores representing better study quality. Due to extensive heterogeneity in study design, a meta-analysis was not conducted, with the results rather presented as a narrative summary of key findings. The vast majority of surgeons conducting a variety of orthopaedic and traumatologic procedures were not exposed to a hazardous level of eye irradiation annually, but surgeons who perform a high volume of fluoroscopy-intensive procedures may exceed guidelines. Leaded eyeglasses reduced eye radiation by about 90%, with sport wrap-around glasses offering better shielding than alternatives, although leaded glasses overall were largely underutilized. Positioning mini C-arms in the standard vertical configuration was shown to provide up to a 13-fold decrease in radiation exposure compared with inverted configuration, while standing perpendicular to the fluoroscope further reduced eye irradiation. We found that orthopaedic surgeons who perform a high volume of fluoroscopy-intensive procedures may be at risk of exceeding recommendations on annual radiation exposure, although exposure can be mitigated through various simple strategies. In particular, this analysis found that the use of sport wrap-around leaded glasses, positioning of mini-C arms in the standard vertical configuration, and standing perpendicular to the fluoroscope provide the most effective means of limiting ocular radiation exposure. As ophthalmic radiation exposure presents a potentially important occupational health hazard to orthopaedic surgeons, further investigations of radiation exposure specific to high-volume, fluoroscopy-intensive orthopaedic practices and long-term ophthalmic outcomes will help determine the extent of the potential harm posed by frequent exposure to intraoperative radiation over the span of a career. Level III, therapeutic study.

Frequency of occupational health hazards and factors responsible among the waste handlers at the tertiary care hospitals of Karachi.

Hospital waste handlers (HWHs) are in contact with contaminated waste that put them at risk for occupational health hazards. The objective of the study was to determine the frequency of occupational health hazards and identify factors contributing to them among the HWHs at tertiary care hospitals of Karachi. A cross sectional survey was conducted from January 2021 till June 2022 on 417 conveniently selected HWHs of the public and private tertiary care hospitals of the Karachi including three Public sector hospitals (Civil Hospital Karachi, National Institute of Child Health, Jinnah Post Graduate Medical Center) and five private sector hospitals (Sohail University Hospital, Darulsehat Hospital, Kharadar General Hospital, Patel Hospital and Hamdard University Hospital) using a structured questionnaire. Chi Square test was applied to determine the differences in occurrence of different hazardous outcomes (Needle stick injury, Sharp Injury, Eye Symptoms, Skin symptoms, Cough) between different groups of age, gender, type of hospitals and status of being trained in Hospital Waste Management (HWM). Around half of the HWHs (52.6%) labeled the bins of the waste according to their level of hazard. Only 17.9% disinfected the infected waste. The proportion of participants who experienced needle stick and sharp injury in the last six months was 16.3% and 15.8% respectively. Majority of them used disposable gloves (95.7%) and face masks (94.3%). One thirds had access to aprons while only 10.5% had access to protective shoes at their work place. HWHs of private sector were significantly less likely to experience Needle stick injuries, skin symptoms, cough, breathing difficulty and throat burning. The HWM practices in tertiary care hospitals of Karachi is far from being satisfactory. HWHs must be trained and monitored for safe disposal of waste.

Analyzing the dependency of earthquake insurance premium on the intensity measure used in probabilistic seismic hazard analysis and fragility curves

Considering the uncertainties associated with earthquake, seismic response of structures, damage caused by the response and the repair costs, determining Earthquake Insurance Premium (EIP) is a challenging task that requires a framework for modeling all inherent risks. Most of the models proposed for EIP determination have two basic components. The first component indicates the probability of seismic hazard (generally obtained from the probabilistic seismic hazard analysis), and the second component indicates the probability of occurrence of a given damage to the structure with respect to different seismic hazard levels (generally obtained from the fragility curves). These two components are interconnected through an intermediate parameter, known as the Intensity Measure (IM), which is of great importance in calculations and has hardly been considered so far. In this study, the dependency of EIP on the IM used in the probabilistic seismic hazard analysis and the fragility curves is analyzed. To this end, the EIP was determined for five types of buildings at low, medium and high seismic hazard levels using two IMs (peak ground acceleration and first mode spectral acceleration). The results of this study warn that the EIP can be highly dependent on the IM, so that for all studied structures, the EIP determined based on peak ground acceleration at a high seismic hazard level is nearly three times as many as the one determined by the first mode spectral acceleration. A significant finding is that when the first mode spectral acceleration is used as the IM, the ratio of EIP at different seismic hazard levels closely matches the ratio of IM at the same levels. This result can be valuable in developing insurance codes and regulations. However, this is not the case for the currently used IM, i.e., peak ground acceleration.

Assessment of heavy metal contamination risk in dry fish from India: A comprehensive study

The widespread presence of heavy metal contaminants in aquatic ecosystems, and consequently in fish, has emerged as a paramount concern owing to the staple role of fish in the Indian diet. The present study addresses heavy metal contamination in dried fish consumed across India and its associated health risks. The objectives of this study were to determine the heavy metal concentrations in dried fish from different regions of India, assess daily heavy metal intake through dried fish consumption, and evaluate the carcinogenic and non-carcinogenic health risks associated with heavy metal exposure. Subsequently, 111 dried fish samples from Guwahati-Assam, Mumbai, Karad-Maharashtra, and Goa were analyzed for eight selected heavy metals using a validated inductively coupled plasma mass spectrometry method results indicated varying contamination levels across locations, with As being the most abundant heavy metal. In Maharashtra and Assam, the heavy metal load in dried fish was as follows: As > Cr > Ni > V > Cd > Pb > Co > Hg. For Goa, the order was As > Cr > Ni > V > Cd > Co > Pb > Hg. Dietary exposure assessments revealed varying levels of exposure between adults and children, with As and Cd posing higher risks to children. The Target Hazard Quotient (THQ) and Hazard Index (HI) values for all metals were within acceptable limit of one. Health risk assessments revealed generally low hazard levels for adults, but higher risks for children, particularly at higher percentiles. Furthermore, As was identified as posing a medium risk of cancer. In essence, this research emphasizes the necessity for strict monitoring and regulations with the aim of controlling health hazards related to heavy metal pollution in food sources.

Deep learning-based GLOF modelling for hazard assessment and risk management

ABSTRACT Glacial Lake Outburst Flood (GLOF) has become a crucial aspect as the increase in the meltdown of glaciers results in the breach of unstable debris dams. Hence, it is essential to understand the nature of the glacial lakes for proper planning and development of the region in the long term. In this paper, a deep learning network is developed for GLOF hazard and risk assessment. The Shepard Convolutional Neural Network Fused Deep Maxout Network (ShCNNFDMN) is developed by fusing the Shepard Convolutional Neural Networks (ShCNN) and the Deep Maxout Network (DMN) based on regression analysis. Here, various data and feature attributes, like geometric properties, location properties, lake-based properties, and global properties are determined from the glacial lake data. Afterthat, hazard assessment is carried out based on these parameters by the ShCNNFDMN. Then, risk assessment is performed based on the hazard levels and the feature attributes. The ShCNNFDMN is analyzed based on metrics, such as Hazard modelling error, Risk prediction error, Mean Average Error (MAE), and R-Squared are found to produce values of 0.462, 0.423, 0.358, and 0.288, respectively. The proposed method is useful in applications, like infrastructure planning, taking preventive and mitigative actions in downstream areas of glacier lakes.

Identification of Relict Landslide Parts Based on Morphometric Data to Determine Potential Hazard Zones Combined with Surface Morphodynamics

The destruction of houses and facilities by landslide causes deaths. In this context, the level of destruction and subjective description of the characteristics can be examined through landslide parts determination. Therefore, this study aims to determine potential landslide hazard zone and houses potentially affected. Global Navigation Satellite System (GNSS) and unmanned aerial vehicle (UAV) are morphometric surveys combined with surface morphodynamics to show potential hazard zones of landslide parts. Meanwhile, Data Elevation Model (DEM) is used to delineate relict landslide and the concept is verified by field observation and orthophoto. Morphometric measurements are collected at each slope gradient by GNSS and surface morphodynamics are investigated on the entire relict landslide area by direct observation and orthophoto data. The combination of morphometric and morphodynamic data describes hazard zone of relict landslide. In addition, the integration of orthophoto and landslide hazard zone data is used to determine potentially affected houses. This study was conducted on landslides 1 and 2 with zone classifications of very high, high, low and very low. The results show that there are different conditions and the most hazardous parts of landslides 1 and 2 are the foot and body, respectively. A total of 75 and 50 houses were potentially affected by landslides 1 and 2, respectively. Identification of hazard zones based on landslide parts determines the boundaries of the area affected. The addition of surface activity processes determines the level of hazard in each of parts, while the combination of morphometric and morphodynamic data shows landslide zone.

Second-Hand Tobacco Smoke Exposure: Results of Particulate Matter (PM2.5) Measurements at Hospitality Venues in Addis Ababa, Ethiopia.

In Ethiopia, a comprehensive smoke-free law that bans smoking in all public areas has been implemented since 2019. This study aimed to evaluate compliance with these laws by measuring the air quality and conducting covert observations at 154 hospitality venues (HVs) in Addis Ababa. Indoor air quality was measured using Dylos air quality monitors during the peak hours of the venues, with concentrations of particulate matter <2.5 microns in diameter (PM2.5) used as a marker of second-hand tobacco smoke. A standardized checklist was used to assess compliance with smoke-free laws during the same peak hours. The average PM2.5 concentrations were classified as good, moderate, unhealthy for sensitive groups, unhealthy for all, or hazardous using the World Health Organization's (WHO) standard air quality index breakpoints. Only 23.6% of the venues complied with all smoke-free laws indicators. Additionally, cigarette and shisha smoking were observed at the HVs. Overall, 63.9% (95% confidence interval: 56-72%) of the HVs had PM2.5 concentrations greater than 15 µg/m3. The presence of more than one cigarette smoker in the venue, observing shisha equipment in the indoor space, and the sale of tobacco products in the indoor space were significantly associated with higher median PM2.5 concentration levels (p < 0.005). Hazardous level of PM2.5 concentrations-100 times greater than the WHO standard-were recorded at HVs where several people were smoking shisha and cigarettes. Most HVs had PM2.5 concentrations that exceeded the WHO average air quality standard. Stricter enforcement of smoke-free laws is necessary, particularly for bars and nightclubs/lounges.

Cumulative characteristics and ecological risk source analysis of soil potentially toxic elements in the northern margin of the Tibetan Plateau.

To understand the soil toxic and hazardous elements content, pollution level, and ecological risk status in the northern margin of the Tibetan Plateau, we collected and analyzed 8273 sets of surface soil samples. Evaluations were conducted using the single-factor pollution index, geo-accumulation, pollution load, and potential ecological risk indices, and source identification correlation and principal component analysis. The results revealed that, compared with the background levels in China, the accumulation of soil arsenic, cadmium, nickel, and chromium was greater in the surface soil of the study area. Additionally, in comparison with Qinghai Province, more mercury accumulated in the surface soil of the study area and owing to the influence of anthropogenic activities. Benchmarking against soil environmental quality standards, the study area exhibited pollution control zones primarily dominated by arsenic and cadmium (3.9%). The spatial distribution revealed distinct zones: a ridge mountain type characterized by arsenic-cadmium-chromium-nickel, a Daban mountain type with solely cadmium presence, and a Longyangxia-Jianzha South type dominated by arsenic. Compared with the Qinghai Province soil background values, evaluations using the Pollution loading index, Geological Cumulative Index, and Potential Ecological Risk Index methods revealed varying degrees of potentially toxic element content exceedance. From an ecological risk perspective, the individual element with the highest potential ecological risk coefficients were mercury, followed by cadmium and arsenic; however, the region's overall ecological risk index was classified as low. Three distinct sources were identified: natural sources leading to high background levels of chromium, nickel, copper, zinc, and mercury; mixed natural and industrial/agricultural sources contributing to elevated cadmium levels; and human activity-related mercury enrichment. Based on the evaluation results, synergistic monitoring of soil and biota in naturally occurring risk zones is recommended to ensure the safety of agricultural and pastoral products. Additionally, ecological impact assessments and pollution source mitigation studies should be conducted in regions influenced by human activities to curb the further degradation of soil ecological quality.

Impacts of hydrogen fraction and equivalence ratio on the explosion characteristics of ethanol/hydrogen mixtures

With the anticipated widespread integration of biofuels and hydrogen fuels within the future energy landscape, the potential explosion hazards after their release within confined spaces under the atmospheric are deserving of heightened attention. The present work takes the mixtures of ethanol and hydrogen as the objects and experimentally studies the impacts of hydrogen fraction and equivalence ratio on the explosion characteristics in a constant-volume explosion vessel at 0.10 MPa and 400 K. The data reveals that an increase in the hydrogen fraction leads to a rise in the maximum explosion pressure during lean explosions but causes a decrease during rich explosions. Nonetheless, the duration of the explosion decreases with the increase of hydrogen fraction in all the explosions. In consideration of explosion pressure, the maximum pressure rise is found to be exponential in relation to the maximum explosion pressure. However, the confidence level diminishes significantly with an increase in the hydrogen fraction. Conversely, the maximum rate of pressure rise during an explosion appears to be a function of the duration of the explosion, suggesting that the reaction rate plays a more pivotal role in determining the hazardous level. Meanwhile, the duration of fast combustion steadily occupies approximately 83 % of the explosion duration. Furthermore, the deflagration index is no more than 30 MPa*m/s, namely, ethanol/hydrogen mixture is a promising fuel with mild hazardous potential.

A holistic approach for assessing occupational health risk due to fugitive emissions in petrochemical processes: Inherent health hazard level index (IHHLI)

AbstractFugitive emissions from petrochemical facilities have become a major concern due to their impact on plant productivity, the environment, and health. In regard to health, petrochemical workers are at higher occupational health (OH) risk due to their continuous exposure to these harmful emissions. Inherent OH and safety indexes are the most common methods used for assessing OH risk due to fugitive emissions. These methods usually focus on the sources of health hazards, such as chemical substances, process conditions, and process equipment. Therefore, these methods are considered good for measuring the severity of the OH risk. However, based on the source, pathway, receptor (SPR) model, the OH risk due to fugitive emissions is also dependent on the pathway and receptor, where leak and exposure hazards may take place, respectively. For a holistic OH risk assessment, these hazards need to be considered. This was achieved by developing an OH risk assessment methodology that provides an effective assessment that takes into consideration hazards at the source, pathway, and receptor. This paper focuses on the source part of the SPR model, while the pathway and receptor parts will be covered in future publications. This paper presents an index‐based method named the inherent health hazard level index (IHHLI) developed for evaluating the severity of the fugitive emission‐induced OH risk. The IHHLI is developed by an expert‐based selection of the most common and relevant health hazard indicators published in the literature. Based on industry testing, the IHHLI can provide a reliable OH hazard evaluation.

Seismic performance of beam-type covered bridge considering the superstructure – substructure interaction and bearing mechanical property

Modern covered bridges have attracted attention due to their multifaceted commercial functionalities, making them increasingly prevalent in construction projects throughout China. To investigate the seismic performance of the beam-type covered bridge, finite element models (FEMs) of conventional building structure, conventional bridge structure and covered bridge structure were established via OpenSEES. The effects of bearing mechanical properties on the seismic response of the whole covered bridge and impacts of lower bridge structure on the interlayer drift ratio of upper building, as well as influences of upper building structure on bearing displacement and pier displacement and stress were deeply explored by using (Incremental dynamic analysis) IDA method. Furthermore, the seismic performance of the covered bridge was evaluated under two levels of seismic hazards. Results indicate that under the seismic events may occur, the interaction between superstructure and substructure is adverse to the longitudinal seismic performance of the superstructure and wall pier of the covered bridge, but do not significantly impact the lateral seismic response of the superstructure. The existence of the superstructure notably reduces the displacement of bearings. Moreover, higher bearing stiffness lead to a more pronounced interlayer drift ratio within the superstructure of the covered bridge. The influence of bearings on the displacement and stress of wall piers is not affected by the superstructure- substructure interaction. This study involved the nonlinearity of the structure and the randomness of seismic actions and clarified the impacts of factors on the seismic response of the beam-type covered bridge. Finally, a reasonable layout of the bearings was proposed.

How to avoid heavy life losses in Liulin-like flash flood events

Abstract. From 11 to 12 August 2021, an extreme rainstorm attacked the Liulin Town, a very common town in Hubei Province, China. The rainstorm triggered flash flood and caused heavy live losses. This study first conducted an analysis on the causes of the flash flood disaster, then, performed a simulation to review the flash flood process, and finally discussed the technical strategies and approaches to avoid life losses in similar cases. The main understandings include: (1) accumulative rainfall of shorter interval and time-sliding is significantly helpful to improve warning accuracy; (2) flash flood risk needs to be evaluated at catchment scale and making room for floods is necessary; (3) residential buildings threatened by flash floods need to rebuild some structures for live-saving in emergency circumstances; and (4) early warning system needs to have capabilities to collect real basin-wide rainfall and flood information, especially in case of rainstorm, and to be smart to judge hazard level.

Morphometric characteristics of the relief and assessment of erosional hazards of the Kalaus River basin, Russia, based on digital modelling

In this work, the main goal was to analyse the erosional hazards within the boundaries of the Kalaus River catchment area.The paper analyses the erosive state of the region's lands, for which industry and cadastral maps, a digital elevation model and satellite images were used. Official data of ministries and departments were used. Geographic information systems – QGIS and SAGA GIS – served as the basis for modelling. The article presents the results of GIS modeling of erosional hazards in the territory of the Kalaus River basin. Based on the (DEM) SRTM digital elevation model, the basic morphometric indicators of the relief were calculated: steepness of the slopes and vertical and horizontal dissection of the relief. Based on morphometric indicators, an integral calculation of the energy of relief and erosion hazard was carried out and a series of relevant thematic maps was created. The values of slope steepness obtained within the boundaries of the basin range from 0° to 51° with average values of 2.5°. The horizontal dissection varies in the range from 0 to 0.84 km/km2, and the erosion bases are characterized by a range of values from – 15.0 to 248.6 m, with an average value of 33.0 m. The formation of the erosional potential of the basin’s relief is facilitated by the location of a significant part of the region on the spurs of the Stavropol Upland, which have widely developed slopes. Based on the calculated raster of the integral energy index of the relief, 3 categories of erosional hazard are identified. Most of the basin of the Kalaus River (58.4 %) is characterised by a low erosion hazard, another 39.0 % of the territory presents an average erosion hazard, and the remaining 2.9 % belongs to territories with a strong erosion hazard. The classification of relief surface shapes based on the Iwahashi and Pike method, which was carried out on the basis of a DEM, shows a much greater prevalence of steep slopes with high convexity in the southern part of the Kalaus River basin.The identified features of the level of erosional hazard of the lands of the Kalaus River basin are recommended to be taken into account in preinvestment, pre‐design and urban project planning of the territories of administrative units located within the boundaries of the basin. Despite the fact that the results of GIS analysis cannot completely replace field erosion surveys, their value as a tool for planning rational land use is obvious. The results of the work can be used to carry out a similar assessment in other regions, primarily in the organisation of agricultural production.

Deterministic approach to assess landslide susceptibility and landslide activity in the Central-Western Region of Slovakia

Quantitative assessments in landslide susceptibility evaluation are typically dominated by statistical analyses. However, this paper employs a deterministic approach to construct such maps, specifically focusing on the stability assessment of shallow landslides with slip surfaces generally not exceeding 5 m in depth at a regional scale. The study area chosen for this research is the landslide-prone region between Hlohovec and Sereď towns in the central-western part of Slovakia. Our focus is on the activation of shallow landslides, representing the youngest, third generation of landslide evolution in the area. For the stability assessment, three scenarios were considered using deterministic analysis: a scenario involving dry slopes, a scenario under partially saturated conditions, and a scenario of fully saturated slopes. This approach enables the assessment of stability conditions based on qualitative parameters derived from both field and laboratory research. The results from the deterministic analysis aid in defining different stages of activity within the landslide body. These Landslide susceptibility maps were verified directly in the field, and most landslides reactivated from 2011 to the present fell into the class with the safety factor below 1.0. In comparison with the landslide hazard map created by using bivariate statistical analysis, it was observed that 89.97% of the area is in a very high level of landslide hazard, given a safety factor below 1.0. This highlights the effectiveness of the deterministic approach in capturing the vulnerability of the region to shallow landslides.

Gaussian process regression driven rapid life-cycle based seismic fragility and risk assessment of laminated rubber bearings supported highway bridges subjected to multiple uncertainty sources

Structural attributes, corrosion of steel rebars in reinforced concrete (RC) columns, thermal oxidative aging of inherent rubber in laminated rubber bearings (LRBs), replacement of LRBs, and the time-dependent seismic hazard level at the bridge site are well recognized as the main factors that affect the accurate assessment of the seismic performance of RC bridges implemented with LRBs. However, the probabilistic seismic demand model (PSDM) and probabilistic structural capacity model (PSCM) of deteriorated bridge components may not exhibit homoscedastic log-linearity. And the expansion of seismic fragility surfaces and seismic risk curves in the temporal dimension requires a considerable computational cost on the nonlinear analysis, which regretfully has not been well addressed in current studies. To fill in this gap, this study proposes a life-cycle based seismic fragility and risk assessment framework for LRBs supported RC bridges considering deterioration mechanisms of bridge components during their life cycles demonstrated by a three-span LRBs supported highway bridge considering multiple uncertainties such as the replacement interval for LRBs. In this framework, Gaussian process regression (GPR) is employed to effectively construct the PSDM and PSCM of deteriorated bridge components, and then the time-dependent seismic fragility surfaces of bridge components and bridge system are established. Life-cycle based seismic risk analysis is conducted to quantify the coupled time-dependent effects of deterioration and site seismic hazard on a newly built bridge during its design service life and a deteriorated bridge within its remaining service life, respectively. Results indicate that GPR can successfully capture the nonlinearity and heteroscedasticity characteristics of PSDM and PSCM, leading to a significant reduced number of nonlinear analysis cases to generate the time-dependent seismic fragility surfaces and seismic risk curves. Consequently, the proposed framework using GPR can significantly improve the accuracy and efficiency of life-cycle based seismic performance assessment when uncertainties of structural attributes, deterioration progress and seismic hazard are taken into consideration.