Hazardous Phenomena Research Articles

Features of the distribution of meteorological parameters by height at the airport in Almaty

Currently, the study of atmospheric parameters that hinder the flight of aircraft and cause damage to aviation equipment is one of the most important issues of meteorological support for aviation. Meteorological support-one of the factors taken into account in the organization, execution, maintenance of flights and air traffic control is the weather. Its main goal is to ensure flight safety. Meteorological parameters and phenomena that are dangerous for aviation can cause serious damage to airlines, including the airport of Almaty. Therefore, the study of the distribution of meteorological parameters affecting aircraft at the airport of Almaty is one of the urgent problems at the present time. This article examines the features of the distribution of meteorological parameters over height for the period 2013-2017. at the airport in Almaty. The following meteorological parameters affecting aircraft (AC) were analyze: air temperature, atmospheric pressure, wind speed and direction, type and size of clouds, as well as the following hazardous phenomena affecting the height: aircraft turbulence, aircraft icing, jet flow, etc. Meteorological data in the form of upper-air diagrams were taken from the Internet from flymeteo.org.

Original

River bank erosion is a hazardous and common phenomenon in diara region near Malda district of North East India during monsoon and post-monsoon periods of every year. One of the significant causes behind the erosion is the textural composition and its arrangement along the river bank. The left bank of Ganga River is texturally very weak along diara region of Malda district. In the present study, the nature of riverbank soil textural composition has been measured by basis parameters analysis and mechanical analysis of soil and its erodibility level. Sieve analysis has been done on all collected soil samples and determines soil basic parameters. The nature of the soil has been derived through the mechanical analysis of particles after Folk and Worst method. Besides that, the degree of soil erodibility has been analyzed through the Bouyoucos Erodibility Index and ROM scale after Roslan and Mazidah. The results show that the erodibility levels become high to the moderate condition along the middle to lower extension of left bank line and relatively low along with upper extension according to ROM scale. Nature of soil along the left bank is dominantly sandy which also indicates the vulnerable condition of bank sites. Basic parameters of soil and its mechanical analysis also reveals that unstable condition exists along with the whole extension of the riverbank line but instability condition is increasing from upper to lower segment of bank line. So the risk of riverbank failure can be measured by determining the textural composition of the soil.

Predicting the unpredictable

Better understanding of hazardous natural phenomena means improved preparedness and the opportunity to mitigate the damaging impact of these natural hazards. For example, improving knowledge about earthquakes can enable safer buildings to be built, as well as disaster prevention measures to be implemented, ultimately saving lives. This is particularly important in a country like Japan, which is earthquake-prone and where earthquakes prove to be very unpredictable. A team of Japanese researchers is seeking to reduce uncertainty in earthquake hazards by conducting statistical analyses of seismic activity, with a focus on the Nankai Trough megathrust earthquake. These investigations have enabled the researchers to estimate the state of the stress in and around the earthquake's focal region, and they believe this may lead to a method for qualitatively evaluating whether the next Nankai Trough earthquake is imminent.

Flash flood risk assessment using geospatial technology in Shewa Robit town, Ethiopia

Flash flood is an extreme flooding event which is quick, short-lived, hazardous phenomena having negative environmental and socio-economic impacts. Flood risk management is essential to reduce the effects of flood on human lives and livelihoods. The main goals of this research were flash flood risk analysis and risk quantification in terms of land use land cover using geo-spatial technology in Shewa Robit town. In the present study, elevation, slope, drainage density, distance from river, NDVI, land use land cover, topographic wetness index and curvature were used as parameters determining flash flood risk. To realize these research objectives, all these data were reclassified in to five classes and different weights for each of them was assigned using analytic hierarchy process. Weighted Sum Overlay (WSO) analyses of ARC GIS software was employed to produce flood vulnerability map. Then, the accuracy of generated flood risk map was validated using historical flood data. According to the result, about 3.08%, 14.62% and 20.66% of Shewa Robit town are at a very high, high and moderate flash flood risk, respectively. In addition to this, flood risk was also quantified in terms of land use land cover. The result indicates that the settlement land use is the most vulnerable with an estimated area of 12.01 ha, 99.57 ha and 174.16 ha in very high, high and moderate risk classes. The outcome of the study will be applicable in flood hazard management and mitigation strategies.

Spatial and temporal aspects of high streamflow periods within the Danube drainage basin in Bulgaria

High flow events are the main prerequisites for floods with negative social and environmental consequences. Their study under uncertain and changing climate gives informative knowledge for further management decisions. This paper seeks to analyze the spatio-temporal parameters of high flow periods within the Danube drainage basin in Bulgaria. Three characteristics of the hazard phenomena: time of occurring, frequency and duration are investigated. The analysis is based on daily discharge data collected from 20 gauging stations for the period 2000–2005. The surplus water quantities are identified by the Threshold level method using fixed values – Q25 and Q5, derived from the flow duration curve. Results show a concentration of the high flow periods during the spring hydrological season, with an average duration up to six weeks. The calculations establish positive correlations between the duration of high flow, the altitude of catchments, and the density of drainage network. The resulting information can serve as a support for the development of preliminary flood risk assessments in the Danube River Basin.

Event Trees and Epistemic Uncertainty in Long‐Term Volcanic Hazard Assessment of Rift Volcanoes: The Example of Aluto (Central Ethiopia)

AbstractAluto is a peralkaline rhyolitic caldera located in a highly populated area in central Ethiopia. Its postcaldera eruptive activity has mainly consisted of self‐similar, pumice‐cone‐building eruptions of varying size and vent location. These eruptions are explosive, generating hazardous phenomena that could impact proximal to distal areas from the vent. Volcanic hazard assessments in Ethiopia and the East African Rift are still limited in number. In this study, we develop an event tree model for Aluto volcano. The event tree is doubly useful: It facilitates the design of a conceptual model for the volcano and provides a framework to quantify volcanic hazard. We combine volcanological data from past and recent research at Aluto, and from a tool to objectively derive analog volcanoes (VOLCANS), to parameterize the event tree, including estimates of the substantial epistemic uncertainty. Results indicate that the probability of a silicic eruption in the next 50 years is highly uncertain, ranging from 2% to 35%. This epistemic uncertainty has a critical influence on event‐tree estimates for other volcanic events, like the probability of occurrence of pyroclastic density currents (PDCs) in the next 50 years. The 90% credible interval for the latter is 5–16%, considering only the epistemic uncertainty in conditional eruption size and PDC occurrence, but 2–23% when adding the epistemic uncertainty in the probability of eruption in 50 years. Despite some anticipated challenges, we envisage that our event tree could be translated to other rift volcanoes, making it an important tool to quantify volcanic hazard in Ethiopia and elsewhere.

Out-Patient Service and in-Patient Service: The Impact of Health Insurance on the Healthcare Utilization of Mid-Aged and Older Residents in Urban China.

PurposeMedical insurance is a disease risk-sharing mechanism that can improve residents’ financial access to medical treatment and thus increase their utilization of health services. This paper aims to identify the impact of different kinds of medical insurances on the use of healthcare for Chinese mid-aged and older urban residents from four aspects: outpatient behaviour, outpatient costs, inpatient behaviour and inpatient costs.Materials and MethodsThe data used in this study were from 2015 China Health and Retirement Longitudinal Study (CHARLS) conducted by Peking University. Binary logit model and multiple linear regression model were used to analyse the impact of health insurance on the use of healthcare, and the PSM method was used to test the robustness of the results.ResultsParticipating in either BMIUSE or BMISURR can significantly improve all kinds of healthcare utilization for mid-aged and older urban groups. However, there are huge differences on the healthcare utilization between BMISUE and BMISURR. Specifically, the probability of using inpatient care and inpatient costs of urban residents enrolled in the BMISUE are 4.2% and 45% higher, respectively, than those covered by the BMISURR, but there are no differences in outpatient care utilization and outpatient costs between these two health insurance programs.ConclusionThis paper suggests that the large gaps between BMISUE and BMISURR only reflect on inpatient care and inpatient costs, there is no difference in outpatient services between these two health insurance programs. “Excessive demand”, “induced demand” and other moral hazard phenomena in BMISUE should be avoided when receiving hospitalization services.

Air curtain to control smoke and fire spread in a ventilated multi-floor building

Compartment fire is a hazardous phenomenon because of the generated poisonous and high-temperature gases. Air curtain systems can be used in order to control the fire spread. This paper examines the numerical simulation method with a focus on the combustion model which can model the poisonous gases and investigates the effect of air curtain on fire. The results of the flamelet generated manifold (FGM) combustion model, which considers all of the poisonous species with detail, in compartment fire with single and multi-floor building have been verified. A three-floor compartment fire scenario with methane as a fuel of 62.9, 500, and 5000 kW heat release rate, which represents over to under-ventilation, was selected as a test case. The impact of air curtains with various supply angles, velocity, and ventilation on pollutants and temperature distribution was examined. The mass fraction of CO and CO2 species reached near zero at angles of 12 and 24, at the over-ventilated case when using air curtain. Therefore, there is no hazard for the upper floors in case of using air curtain. However, in the under-ventilated case, it is necessary to improve the efficiency of air curtain by using ventilation in the fire room and increasing the exhaust velocity of the air curtain.

Radar reflectivity signatures and possible lead times of warnings for very large hail in Poland based on data from 2007-2015

Abstract Hail involving very large hailstones (maximum diameter ≥ 5 cm), is a rare but very hazardous phenomenon in Poland, and can be forecast using reflectivity signatures. Every year, Poland experiences from one to over a dozen storms with such large hailstones. Despite the current recommendations regarding polarimetric techniques used in hail risk monitoring, Poland does not have a fully polarimetric radar network. Therefore it is essential to check hail detection capabilities using only reflectivity techniques based on individual radar systems involving hail detection algorithms such as Waldvogel et al. (1979) or Vertically Integrated Liquid thresholds connected with manual signature analysis to get better warning decisions. This study is aimed to determine the reflectivity features, thresholds and lead times for nowcasting of severe storms with very large hailstones in Poland, using data from the Polish radar system and from the European Severe Weather Database for the period 2007–2015. Most incidents involving very large hailstones were linked to supercell storms with distinctive reflectivity signatures, however, some storms with extremely large hailstones presented very poorly developed signatures. These signatures enabled the prediction of hail involving very large hailstones approximately 29 minutes before it fell. The Lemon (1980) criterion and WER were found to be the best hail predictors for Polish radar system conditions.

Crowding out agricultural insurance and the subsidy system in Italy: empirical evidence of the charity hazard phenomenon

PurposeThe term “charity hazard” refers to the issue of the crowding out of insurance by co-existing relief programs in the context of different institutional governmental disaster schemes. In this context, the aim of this paper is to verify if the charity hazard phenomenon exists in the Italian agricultural insurance scheme.Design/methodology/approachAnnual data regarding crop insurance, subsidies and farm structure were extracted from ISMEA, ISTAT and FADN databases. A SYS-GMM dynamic panel model was estimated, considering the 2010–2017 time period and the Italian Regions as units of the analysis.FindingsThe empirical results highlight a negative relation between crop subsidies and the farmers' policies and total premium paid. The disincentive and crowd-out effects of public aid and subsidies on the choice of whether or not to take out an agricultural insurance policy ends up being one of the key factors for the low level of penetration of the agricultural insurance in Italy.Practical implicationsSince the diffusion of agricultural insurance can contribute to the general objective of sustainability and resilience, the implementation of alternative solutions to subsidies could be needed (e.g. the introduction of mandatory insurance against adversities or financial support for a geographically specific insurance tool).Originality/valueInvestigating empirically the determinants of the agricultural insurance policy diffusion among the Italian Regions, this study ensures an original contribution to the scientific progress in the field, demonstrating the existence of charity hazard caused by the public subsidies provision.

Pyroclastic Density Current Facies in the Millennium Eruption of Tianchi Volcano, Northeast China: Insights From Topography, Stratigraphy, Granulometry, and Petrography

The 946 A.D. Millennium Eruption (ME) of Tianchi volcano produced masses of pyroclastic density current (PDC) deposits that cover an area that extends roughly 50 km from the crater. In order to understand PDC dynamic processes, this study examines the proximal to distal variations in the PDC facies by analysing the topography, stratigraphy, granulometry and petrography. Topography of Tianchi volcano has different slopes, including the cone (>6°), lava shield (2–5°) and lava plateau (20 km) are less than 10 m thick, with coarse-tail layers, ground surge layers, climbing layers, and carbonized woods in the plateau. The degree of PDC welding decreases with the distance from the crater. From the proximal to the distal strata, the emplacement temperature of the PDCs decreased from 740 °C to 280 °C. The medial layers indicate a gravitational differentiation effect and weakened transportation of the PDCs, which led to the formation of thick beds. The distal PDCs demonstrate fluidisation characteristics and a density far lower than those of the proximal and medial strata, which exhibit clear stratification. Grain size data (<64 mm) show that the median diameters decreases with increasing distance from the crater. Rhyolitic and trachytic pumice are found in the PDCs and are assumed to be associated with the composition of the magma chamber. Magmatic mixing structures were confirmed by microscope observations. The volume estimation of PDCs in China is 6.9806 km3. The PDCs exhibit characteristics of high temperatures, large volumes, flowing over long distances, and having the ability to climb hills. The PDCs were the most hazardous volcanic phenomena and can provide a reference for future potential PDC hazards around the Tianchi volcano.

Health Impacts of Volcanic Activity in Oceania.

Volcanoes cause a wide range of hazardous phenomena. Close to volcanic vents, hazards can be highly dangerous and destructive and include pyroclastic flows and surges, ballistic projectiles, lava flows, lahars, thick ashfalls, and gas and aerosol emissions. Direct health impacts include trauma, burns, and exacerbation of respiratory diseases. Far-reaching volcanic hazards include volcanic ashfalls, gas and aerosol dispersion, and lahars. Within Oceania, the island arc countries of Papua New Guinea (PNG), the Solomon Islands, Vanuatu, Tonga, and New Zealand are the most at-risk from volcanic activity. Since 1500ad, approximately 10,000 lives have been lost due to volcanic activity across Oceania, with 39 lives lost since 2000. While volcano monitoring and surveillance save lives, residual risks remain from small, sudden, unheralded eruptions, such as the December 9, 2019 eruption of Whakaari/White Island volcano, New Zealand which has a death toll of 21 at the time of writing. Widespread volcanic ashfalls can affect the habitability of downwind communities by contaminating water supplies, damaging crops and buildings, and degrading indoor and outdoor air quality, as well as disrupting transport and communication networks and access to health services. While the fatality rate due to volcanic eruptions may be low, far greater numbers of people may be affected by volcanic activity with approximately 100,000 people in PNG and Vanuatu displaced since 2000. It is challenging to manage health impacts for displaced people, particularly in low-income countries where events such as eruptions occur against a background of low, variable vaccination rates, high prevalence of infectious diseases, poor sanitation infrastructure, and poor nutritional status. As a case study, the 2017-2018 eruption of Ambae volcano, Vanuatu caused no casualties but triggered two separate mandatory off-island evacuations of the entire population of approximately 11,700 people. On the neighboring island of Santo, a health disaster response was coordinated by local government and provided acute care when evacuees arrived. Involving primary care clinicians in this setting enhanced local capacity for health care provision and allowed for an improved understanding of the impact of displacement on evacuee communities.

Numerical research on adverse effect of muzzle flow formed by muzzle brake considering secondary combustion

The simulation of the artillery interior and intermediate ballistics problem is performed to investigate the influence of a gas dynamics device, muzzle brake, on the muzzle hazard phenomena, such as flash and blast waves. The correlation of the chemical reactions with the characteristics of the muzzle flow field is analyzed by the simulation for a further understanding of the secondary combustion phenomenon of the muzzle flow. The novel structure of muzzle flow caused by the muzzle brake is presented by the simultaneous solution of the interior ballistics model and multi-species Navier-Stokes equations in order to analyze the influence of the muzzle brake structure on the chemical reactions. The secondary combustion of the muzzle flow due to the oxygen-supplement chemical reactions is obtained by the chemical reaction kinetic model. The interaction of the blast waves released from the muzzle brake is illustrated in detail and the mechanism of the formation of muzzle flash is analyzed. This research provides a reference for the studies on the suppression of the muzzle flash.

Analysis, monitoring and simulation of dust hazard phenomenon in the northern Persian Gulf, Iran, Middle East

Dust is a particulate matter in the atmosphere that is created by natural and human agents. Dust has negative effects on various parts of human life, including agriculture, health and economics. In recent decades, in various areas with a lack of rainfall and drought being contested, dust has happened there. One of these areas is the northern part of the Persian Gulf in Iran which has been exposed to dust in recent years. The purpose of the present study was to evaluate and predict the hazardous phenomenon of dust in the western strip of Iran. Therefore, the data of dust from 14 synoptic stations of the study area (1990–2018) using panel data-hybrid neural network and adaptive neuro-fuzzy inference system (ANFIS) models were used. Finally, TOPSIS and simple additive weighting (SAW) multi-criteria decision-making (MCDM) models were used to prioritize more dust-prone areas. The results showed that the reliability of the panel data-hybrid neural network error estimation models is more than the ANFIS. Based on prediction models, the highest probability of occurrence of the maximum dust in the future was observed at Sarpol-e Zahab and Abadan stations (128.917 and 120.709%, respectively). According to the SAW model, the highest probability of occurrence of dust was at Abadan station (998%) and based on the TOPSIS model, Eslamabad-e Gharb, with 997%. It is necessary the inter-organizational cooperation by contracting an international memorandum with neighbouring countries in addition to domestic actions to reduce the damage caused by the dust phenomenon in the study area.

GEOPHYSICAL STUDIES AND STRENGTHENING A LAYERED AND WATER-SATURATED SOIL MASS IN THE KYIV METRO CONDITIONS

Purpose. An urgent issue for shallow underground tunnels in difficult engineering and geological conditions is the determination of the physical and mechanical properties of soils not only during engineering surveys, but also when they are studied using geophysical methods for studying ground conditions. In addition, it is important to choose ways to improve the properties of soils by strengthening, especially in areas where their strength characteristics are reduced. This ensures the efficient operation of tunnels with the elimination of hazardous phenomena such as vibration creep of soils and deformations of the track and lining. Methodology. Using the existing provisions on geophysical research, in order to identify the weaknesses of the layered and water-saturated massif and justify ways to strengthen it, the basics of a comprehensive study and production implementation have been developed to increase the level of safe operation of metro tunnels. Findings. Geophysical studies were carried out to identify weaknesses in the soil stratum along the route of the running tunnels of the Syretsko-Pechersk line of the Kyiv metro (the left bank of the Dnipro) and it was established that in present conditions, to strengthen weak water-saturated and layered soils, it is necessary to use methods of mixing soils with binders that are injected under pressure. Originality. Based on the performed analytical studies, the dependence of the porosity of weak water-saturated soils on the ratio of the acceleration of vibrations to the acceleration of gravity at certain frequencies of the path vibration caused by the movement of metro trains was obtained, and the parameters of soil strengthening on the sides and the bottom of the rim of the running tunnels were determined. Practical value. The use of geophysical methods for determining weak spots in the soil massif allowed them to be strengthened in the existing shallow underground tunnels and reduce the risk of their dangerous operation.

Machine Learning-Based and 3D Kinematic Models for Rockfall Hazard Assessment Using LiDAR Data and GIS

Rockfall is one of the most hazardous phenomena in mountainous and hilly regions with high and steep terrain. Such incidents can cause massive damage to people, properties, and infrastructure. Therefore, proper rockfall hazard assessment methods are required to save lives and provide a guide for the development of an area. The aim of this research is to develop a method for rockfall hazard assessment at two different scales (regional and local). A high-resolution airborne laser scanning (ALS) technique was utilized to derive an accurate digital terrain model (DTM); next, a terrestrial laser scanner (TLS) was used to capture the topography of the two most critical areas within the study area. A staking machine-learning model based on different classifiers, namely logistic regression (LR), random forest (RF), artificial neural network (ANN), support vector machine (SVM), and k-nearest neighbor (KNN), was optimized and employed to determine rockfall probability by utilizing various rockfall conditioning factors. A developed 3D rockfall kinematic model was used to obtain rockfall trajectories, velocity, frequency, bouncing height, kinetic energy, and impact location. Next, a spatial model combined with a fuzzy analytical hierarchy process (fuzzy-AHP) integrated in the Geographic Information System (GIS) was developed to assess rockfall hazard in two different areas in Ipoh, Malaysia. Additionally, mitigation processes were suggested and assessed to provide a comprehensive information for urban planning management. The results show that, the stacking random forest–k-nearest neighbor (RF-KNN) model is the best hybrid model compared to other tested models with an accuracy of 89%, 86%, and 87% based on training, validation, and cross-validation datasets, respectively. The three-dimension rockfall kinematic model was calibrated with an accuracy of 93% and 95% for the two study areas and subsequently the rockfall trajectories and their characteristics were derived. The assessment of the suggested mitigation processes proves that the proposed methods can reduce or eliminate rockfall hazard in these areas. According to the results, the proposed method can be generalized and applied in other geographical places to provide decision-makers with a comprehensive rockfall hazard assessment.

An investigation of surface deformation over oilfield in Southwest Iran (2003–2010) using InSAR and physical modelling

ABSTRACT Land subsidence is one of the most hazardous phenomena. Rapid rate subsidence corresponds to human activities such as subsurface withdrawal. Therefore, local changes in surface elevation and its associated response has the potential to damage the industrial structures. In this research, the small baseline subset (SBAS) algorithm is applied to perform an Interferometric Synthetic Aperture Radar (InSAR) time series analysis within 2003 and 2010 over a giant oilfield located in the Zagros fold-thrust belt in southwest of Iran. Thirty-one interferograms are generated using 18 Envisat ASAR images. The mean velocity map obtained in the Line-Of-Sight (LOS) direction of satellite to the ground reveals the maximum subsidence on order of 17.3 mm per year over the field due to both tectonic and non-tectonic features. In order to assess the effect of non-tectonic features such as petroleum exploitation on surface displacement, the results of InSAR have been compared with the oil production rate. Also, a physical model of reservoir pattern has been developed using 2D seismic profiles as the way to estimate tectonic deformation which indicates the influence of depth variations of the Gachsaran salt decollement on structural style.

Disturbance estimator and smith predictor-based active rejection of stick–slip vibrations in drill-string systems

ABSTRACTStick–slip vibrations are widespread and hazardous phenomena in drilling practice. The objective of this paper is to develop a simple and general control strategy to minimise such vibrations together with unknown disturbances. Taking into account the transmission delay of the torsional energy from the surface to downhole, a neutral-type drill-string model is established and applied rather than a lumped-parameter model that cannot provide satisfactory modelling precision. Based on this neutral-type model, the major contribution consists of the combination of disturbance estimator and smith predictor to develop a robust vibration control scheme for drill-string systems. One conspicuous advantage of this scheme is that the effects of stick–slip vibrations and external disturbances are estimated without the need for any prior knowledge in the control input channel, and are offset correspondingly. Simulations confirm that this control scheme can achieve effective suppression of stick–slip vibrations with good tracking and disturbance rejection performance.

Polymers Decorated with Functional Motifs for Mitigation of Steel Corrosion: An Overview

Corrosion is a hazardous phenomenon having a devastating impact on technological and industrial applications, particularly in the oil and gas industries. Therefore, controlling the corrosion of metals is an important activity of technical, economical, environmental, and aesthetical importance in order to save huge expenses in materials, equipment, and structure. The use of corrosion inhibitors is one of the best options for controlling the metallic corrosion in various corrosive media. Numerous problems aroused with the use of inorganic and small molecule organic corrosion inhibitors, and the use of polymeric corrosion inhibitors came into limelight. This review article provides an overview of the recent development of different classes of corrosion inhibitors with special emphasis on different functional motifs of natural, synthetically modified natural, and synthetic polymeric materials. The significance, mechanism, and challenges of using polymeric materials as corrosion inhibitors are also highlighted in the review.

The Russian Construction System’s Goal of Reducing the Cost of Mass Residential and Public Buildings

Almost all human professional activity is realized via some type of system. A high-quality work system must be created taking into account the requirements of professionals with the corresponding specialties. Otherwise, the system and the professional activity of its associated employees will be ineffective as a minimum. A good example is Russia’s construction system. The present article’s analysis of the main provisions of Russian federal construction laws and regulations shows that the main aim in construction is the protection of people’s lives and health in residential and public buildings under the impact of hazardous natural phenomena, which in the Russian construction system is done in gross violation of articles 2 and 72 of the Russian Federation Constitution. For example, populated areas—the largest construction projects in Russia—are not even acknowledged as capital construction projects by federal laws and regulations, which makes it possible to cheapen the construction of mass residential and public buildings. Based on a number of theoretical technical requirements on construction of residential and public buildings, the article substantiates the thesis that the Russian construction system should contain a particular major element that could solve the problem of protecting human life and health under the impact of natural hazards: a group of regional specialists with in-depth knowledge of local conditions.