Catastrophic Scenarios Research Articles

Some Considerations for Using Numerical Methods to Simulate Possible Debris Flows: The Case of the 2013 and 2020 Wayao Debris Flows (Sichuan, China)

Using a numerical simulation method based on physical equations to obtain the debris flow risk range is important for local-scale debris flow risk assessment. While many debris flow models have been used to reproduce processes after debris flow occurrence, their predictability in potentially catastrophic debris flow scenarios has mostly not been evaluated in detail. Two single-phase flow models and two two-phase models were used to reproduce the Wayao debris flow event in 2013. Then the Wayao debris flow event in 2020 was predicted by the four models with the same parameters in 2013. The depth distributions of the debris source and deposition fan were mapped by visual interpretation, electric resistivity surveys, field measurements, and unmanned aerial vehicle (UAV) surveys. The digital elevation model (DEM), rainfall data, and other simulation parameters were collected. These models can reproduce the geometry and thickness distribution of the debris flow fan in 2013. However, the predictions of the runout range and the deposition depth are quite different from the actuality in 2020. The performance and usability of these models are compared and discussed. This could provide a reference for selecting physical models to assess debris-flow risk.

Evaluating the potential severity of biogas toxic release, fire and explosion: consequence modeling of biogas dispersion in a large urban treatment plant

Objectives. Biogas production in treatment plants for energy generation has increased in recent years. This study aimed to model the consequence of biogas release in a large urban treatment plant. Methods. The study modeled biogas storage tank consequences in a large urban treatment plant in Iran. Due to potential for biogas harmfulness, three consequences of toxic release, fire and explosion were evaluated. Scenarios were evaluated in the worst-case situation. All modeling steps were performed using PHAST version 7.2. Results. In the case of catastrophic reservoir rupture in summer, distances of 3788.94, 128.86 and 91.72 m from the reservoir in the wind direction will be in the range of 100, 500 and 1000 ppm biogas, respectively. Study of pressure values due to explosion in the catastrophic rupture scenario revealed that distances of 57.19, 14.70 and 115.84 m from the biogas reservoir were in the range of 0.02, 0.13 and 0.2 bar pressure increase, respectively. Conclusion. Due to the treatment plant’s location in a dense urban area, biogas dispersion could lead to exposure of many people to high-risk areas. Therefore, taking control measures comparable with the consequence modeling output can be a practical step toward reducing vulnerability against such incidents.

Sanctions and scenarios of economic development of the Russian Arctic territories (the case of the Yamalo-Nenets Autonomous District)

Relevance. The sanctions against Russia in 2022 affected almost all areas of the country’s economic activity. The sanctions may have varying effects on different territories of Russia. Mono-sectoral regions specializing in the production of primary raw materials are faced with the highest uncertainty. Research objective. The main purpose of the study is to develop and describe scenarios for the economic development of the Yamalo-Nenets Autonomous District under the pressure of sanctions. As part of this task, the impact of restrictions on the development of municipalities in Yamal is assessed, with a special focus on the areas with new hydrocarbon deposits in the Arctic zone. Data and methods. The study relies on the scenario method and the System of National Accounts to calculate the key indicators of economic development, which are defined as aggregated parameters (gross regional product, investment, tax revenues of the consolidated budget, and employment). Results. The impact of sanctions on the development of the Yamalo-Nenets Autonomous District is considered through the three scenarios: inertial, negative, and catastrophic. Under the inertial scenario, the key indicators will not change, and the pace of economic development will decrease. Under the negative scenario, investment projects will be put on hold and a limited deterioration in economic indicators will be observed. Under the worst-case scenario, there will be a serious drop in the key indicators, especially investment and employment. Conclusions. The imposed sanctions prohibiting the supply of high-tech equipment and limiting the supply of natural gas and oil to world markets will not be destructive for Yamal even in the catastrophic scenario. However, these restrictions will seriously limit economic development, gradually worsening the prospects for the development of the Arctic territories and the region’s ability to maintain the current standards of living.

An Efficient Homotopy Method for Solving the Post-Contingency Optimal Power Flow to Global Optimality

Optimal power flow (OPF) is a fundamental problem in power systems analysis for determining the steady-state operating point of a power network that minimizes the generation cost. In anticipation of component failures, such as transmission line or generator outages, it is also important to find optimal corrective actions for the power flow distribution over the network. The problem of finding these post-contingency solutions to the OPF problem is challenging due to the nonconvexity of the power flow equations and the large number of contingency cases in practice. In this paper, we introduce a homotopy method to solve for the post-contingency actions, which involves a series of intermediate optimization problems that gradually transform the original OPF problem into each contingency-OPF problem. We show that given a global solution to the original OPF problem, a global solution to the contingency problem can be obtained using this homotopy method, under some conditions. With simulations on Polish and other European networks, we demonstrate that the effectiveness of the proposed homotopy method is dependent on the choice of the homotopy path and that homotopy yields an improved solution in many cases. For at least 5% of the test cases, bad local minima were identified, and the homotopy method yielded a solution that was significantly better than state-of-the-art interior point methods in terms of reducing the violation cost during a catastrophic contingency scenario.

Моделирование количественных и качественных характеристик стока реки Невы в условиях внешних воздействий на водосбор

Two tasks related to the study of environmentally safe water supply in St. Petersburg have been solved. These are predictive estimates of possible changes in the runoff of the Neva River as a result of climate change and the possible consequences of an emergency at the Krasny Bor toxic wastes landfill. The tasks were solved using the methods of mathematical modeling. Scenarios RCP 2.6 and RCP 8.5 are taken as the basis for predicting possible climate changes - the best and worst in terms of environmental impact. Runoff calculations using the specified climate scenarios showed an increase in runoff under the RCP 8.5 scenario and its decrease under the RCP 2.6 scenario. It has been established that the process of dilution of discharged pollutants from the Krasny Bor landfill as they transport towards the water intakes of St. Petersburg depends on the emergency scenario, hydrological conditions, and the choice of maximum permissible concentrations value for each chemical. The negative impact of the destruction of the embankment of pits with pollutants may be insignificant for municipal water intakes due to dilution processes in the hydrographic network of the catchment. At the same time, hypothetical catastrophic scenarios (terrorist attack, earthquake) in some cases can lead to serious problems with water quality in municipal water intakes.

Destination Babel

ABSTRACT This article proposes a contemporary reading of the Tower of Babel story. The objective is to set the foundations of an ethic of communication that considers the notion of a global community formed by those who “speak the same language.” Our analysis is a trilateral hermeneutic exercise that places the story of the Tower of Babel in the contemporary context: the narrative of the Bible, according to Chouraqui’s very literal translation from the Hebrew text, the rabbinical exegesis of the Midrash, the Talmud of Babylon and the Zohar, and the imperative of responsibility according to Hans Jonas. Alongside to Jonas’s heuristic of fear, based on futuristic projections of catastrophic scenarios, we propose a heuristic of memory that sheds light to the ethics of exile as a key notion to accept imperfect and disruptive communication in a more compassionate and collaborative way.

The simultaneous application of control interventions can lead to catastrophic epidemic scenarios

We analyze the evolution of an infectious disease if infectious individuals are treated or isolated. The analysis of the model shows catastrophic scenarios for the population in which bringing R0 below 1 is not enough to decrease the number of infectious individuals. Finally, we show three scenarios for the behavior of the model solutions in which multiple endemic equilibria exist.

Qualitative Theory of Two-Dimensional Polynomial Dynamical Systems

A qualitative theory of two-dimensional quadratic-polynomial integrable dynamical systems (DSs) is constructed on the basis of a discriminant criterion elaborated in the paper. This criterion enables one to pick up a single parameter that makes it possible to identify all feasible solution classes as well as the DS critical and singular points and solutions. The integrability of the considered DS family is established. Nine specific solution classes are identified. In each class, clear types of symmetry are determined and visualized and it is discussed how transformations between the solution classes create new types of symmetries. Visualization is performed as series of phase portraits revealing all possible catastrophic scenarios that result from the transition between the solution classes.

Evolution of damage control surgery in non-traumatic abdominal pathology: a light in the darkness.

Damage control surgery is based on temporal control of the injury, physiologic recovery and posterior deferred definitive management. This strategy began in the 1980s and became a formal concept in 1993. It has proven to be a strategy that reduces mortality in severely injured trauma patients. Nevertheless, the concept of damage control in non-traumatic abdominal pathology remains controversial. This article aims to gather historical experiences in damage control surgery performed in non-traumatic abdominal emergency pathology patients and present a novel management algorithm. This strategy could be a surgical option to treat hemodynamically unstable patients in catastrophic scenarios such as hemorrhagic and septic shock caused by peritonitis, pancreatitis, acute mesenteric ischemia, among others. Therefore, damage control surgery is light amid better short- and long-term results.

Denial-of-Service Attack on IEC 61850-Based Substation Automation System: A Crucial Cyber Threat towards Smart Substation Pathways.

The generation of the mix-based expansion of modern power grids has urged the utilization of digital infrastructures. The introduction of Substation Automation Systems (SAS), advanced networks and communication technologies have drastically increased the complexity of the power system, which could prone the entire power network to hackers. The exploitation of the cyber security vulnerabilities by an attacker may result in devastating consequences and can leave millions of people in severe power outage. To resolve this issue, this paper presents a network model developed in OPNET that has been subjected to various Denial of Service (DoS) attacks to demonstrate cyber security aspect of an international electrotechnical commission (IEC) 61850 based digital substations. The attack scenarios have exhibited significant increases in the system delay and the prevention of messages, i.e., Generic Object-Oriented Substation Events (GOOSE) and Sampled Measured Values (SMV), from being transmitted within an acceptable time frame. In addition to that, it may cause malfunction of the devices such as unresponsiveness of Intelligent Electronic Devices (IEDs), which could eventually lead to catastrophic scenarios, especially under different fault conditions. The simulation results of this work focus on the DoS attack made on SAS. A detailed set of rigorous case studies have been conducted to demonstrate the effects of these attacks.

COVID-19 and Spanish flu-18: review of medical and social parallelisms between two global pandemics.

SummaryThe intrusion of infectious diseases in everyday life forces humans to reassess their attitudes. Indeed, pandemics are able catalyze rapid transitions in scientific knowledge, politics, social behaviors, culture and arts. The current Coronavirus diesease-19 (COVID-19) outbreak has driven an unprecedented interest toward the influenza pandemic of 1918. The issue is whether history can shed light on the best preventive response and future scenarios. The aim of this review is to highlight the parallelism between the two pandemics. Starting from epidemiology and clinical features, but further focusing on social and cultural issues, it is possible to unreveal great similarities. Their outbreak pattern lead to hypothesize a similar duration and death burden in absence of effective vaccines or innovative treatments for COVID-19. Thus, then as now, preventive medicine represents the first and most effective tool to contain the course of the pandemic; being treatments available only supportive. At the same time,both pandemics shared the same pattern of narration (e.g. scapegoating) and the same impact on minorities in high-income countries. Furthermore, visual art responded to pandemic issues in 2020 in the form of Graffiti art, while similar role was ruled by Expressionism movement during the Spanish flu. Photography also was capable to document both catastrophic scenarios. Thus, it is possible to find a lot of clinical and social similarities between the two pandemics. Nevertheless, if the Spanish flu was not unforseen, COVID-19 spillover was partially predictable and its global impact will hopefully not be overshadowed by a major crisis such as World War I.

Global distribution of forest classes and leaf biomass for use as alternative foods to minimize malnutrition

AbstractDue to the ready availability of tree leaves in many geographies, the alternative food of leaf concentrate currently has the potential to alleviate hunger in over 800 million people. It is therefore potentially highly impactful to determine the edibility of leaf concentrates, which are in the same regions as the world's most undernourished populations. Unfortunately, the toxicity of leaf concentrate for most common tree leaf types has not been screened and the cost of doing so demands a prioritization. This preliminary study explores this potential solution to world hunger by finding the forest classes most likely to offer proximate access to the world's hungry, thus providing the basis for a prioritized list of leaf types to screen for toxicity. Specifically, this study describes a novel methodology for mapping available green leaf biomass and corresponding forest classes (e.g., tropical moist deciduous forest), and their spatial relationship to the global distribution of people who are underweight. These results will be useful for developing a targeted list of tree species to conduct leaf toxicity analysis on, in the interest of developing leaves as an alternative food source for both current malnutrition problems and global catastrophic scenarios.

Conditions are ideal for a new climate club

Annual global greenhouse-gas emissions have been rising steadily for decades and show no sign of peaking. That is, humankind is not making enough progress to exclude a possibly catastrophic climate scenario. Protecting the climate is difficult because of free-riding: emissions abatement costs are largely national but the benefits from climate stability are global. Dealing with this problem needs to be at the core of a new climate strategy. This article argues that both technological and political conditions are now ideal to establish a new climate club, in which members commit to stronger domestic climate measures and agree on the coordinated introduction of carbon border adjustment measures. On the technology side, there have been stunning clean technology cost reductions. This will underpin the climate club: as abatement costs fall, club stability can be more easily achieved. On the political side, we now see the United States, European Union and China – representing half of global greenhouse gas emissions – sharing for the first time a common climate ambition while popular support in all economies is also high for substantial climate actions. These two changes make a climate club more likely stable as the benefits from deviating from the club have diminished. A relatively weak penalty, such as carbon border adjustment measure, may then suffice for club stability. This climate club would also create incentive for other countries to join the club, thus making it a catalyst for tougher climate action worldwide.

El modelo de comunicación SARS-CoV-2: salvar la imagen gubernamental y sacrificar la vida de los ciudadanos

In addition to the application of various material, organizational, and financial measures by the Mexican government to address the coronavirus-19 pandemic in 2020, the implementation of an effective communication strategy to support such actions was also essential. However, this information project produced many contradictions and serious errors that, instead of strengthening the state programs in the epidemiological sphere, weakened them to a significant degree, causing great confusion, psycho-emotional wear and tear, and loss of many human lives. Thus, the government communication strategy became a confusing, incoherent process, unclear about the seriousness of the threat, abusing technical or political explanations, discretionary handling of data and, with serious disagreements between the same authorities and technical experts. In short, this communication model of the left of the Fourth Transformation put the political interests of defense of the government image before the priority of the preservation of the lives of citizens, leading the country to a huge catastrophic scenario of collective health.

Post-flood field investigation of the June 2020 flash flood in the upper Muráň River basin and the catastrophic flash flood scenario

Abstract After a dry spring, in June 2020 several intense storms occurred at the headwaters of the small basins of the Muráň and Zdychava rivers in the territory of the Muránska planina National Park (Slaná River basin, Slovakia). In the first part of the study– according to a hydrological survey made by the authors after the flash flood – the peak discharge was reconstructed at several Muráň River profiles. Next, the flash flood waves were reconstructed by the rainfall-runoff model NLC (non-linear cascade). The results of modelling based on field investigations show that, despite the extreme precipitation event (108 mm per 1 hour at the precipitation gauging station at Predná Hora), the peak flow rates were not exceptional in selected profiles on the Muráň River. The fact that extreme precipitation above 120 mm fell in a relatively very small area at the division of the Muráň and Zdychava rivers’ water contributed to this result. In the second part, a catastrophic 1000-year rainfall event scenario on the Zdychava River basin has been prepared. In analysing time series and identifying T-year daily rainfall depths, daily data was used from six precipitation stations in the vicinity of Muránska planina. Then, the 1000-year discharge of the Zdychava at Revúca was simulated by the calibrated NLC model. In such an extreme precipitation scenario, the peak flow rate would reach 105.15 m3 s−1, i.e. with a specific runoff of 1.78 m3 s−1 km–2. The total runoff in an 18-hour period would be 1.119 million m3, representing 21.11% of the rainfall (5.301 million m3).

Static Integration Based on Stochastic P-Time Petri Nets of Maintenance Scheduling for Railway Transport Equipment

In transport systems, all equipment requires maintenance, which directly affects the machine’s availability and consequently the planned transport schedule. The purpose of this paper is to carry out a method for integrating recovery jobs in railway systems. The proposed method allows the insertion of preventive and corrective maintenance operations when the transport equipment is available in order to minimize periods of inactivity, avoid catastrophic scenarios, and maintain stability and safety of the studied networks. A computing algorithm, allowing insertion of the planned recovery tasks in periods of metro availability, without changing the initial scheduling solution, is established. Finally, we illustrate the implementation of the proposed approach on Tunisian Sahel railway transport networks.

Climate change effect on Octopus maya (Voss and Solís-Ramírez, 1966) suitability and distribution in the Yucatan Peninsula, Gulf of Mexico: A correlative and mechanistic approach

Fisheries play critical roles in food supply and income for human communities worldwide. Unfortunately, the fishery distribution have been changing due to anthropogenic climate change (CC). In this sense, this study analyses were directed to predict the suitability and distribution of red octopus (Octopus maya), an endemic and commercially important species of the Yucatan Peninsula (YP) in Mexico under different CC scenarios. For this purpose, a correlative (CNM) and mechanistic (MNM) niche models based on temperature and salinity and on metabolic scope, respectively, were projected to different Representative Concentration Pathway (RCP) scenarios (2.6, 4.5, 6, 8.5) for the 2040–2050 and 2090–2100 periods. The CNM results suggest that red octopus suitability and potential distribution (PD) could be slightly reduced for the RCP 2.6 scenario. Whereas, RCP 4.5 shows higher suitabilities at the northern region of the YP, which is characterized by a seasonal upwelling which could act as climate refugia. In contrast, a significant suitability and PD reduction occurs during 2090–2100 for the RCP 6 and 8.5 scenarios. On the other hand, MNM indicates the red octopus could retain most of its PD except for the most catastrophic scenario, finding climate refugia north of the YP and deeper waters. Overall, the CNM is more pessimistic than MNM regarding forecasts. Differences between outputs could be based on the MNM using a single variable as proxy to a multivariate niche and the statistical weight of surface environmental variables in the CNM compared to MNM, which considered only bottom temperature data. In addition, coastal data may be overrepresented, which may bias the CNM. Regardless of the differences in the results, both approaches usually predicted suitability reduction in all RCP scenarios showing that temperatures of ~30 °C are detrimental for the red octopus. Assuming that a relationship between abundance and the niche suitability exists, landings in the region will be reduced and less accessible for small-scale fisheries, which is especially important since Mexican regulations assume this species will benefit from CC.

A simple model with peer pressure: the antisocial behavior case

Antisocial behaviors such as consumption of addictive substances and eating disorders are modeled using a SIR model. We propose a function l(y(t)) that describes the relapse-recovery-recycling rate. l(y(t)) describes either strengthening or weakening of convictions of recovered individuals to relapse in antisocial behaviors. We show that a wide variety of functions can induce the existence of multiple equilibria points for R0 < 1 which is a catastrophic scenario for the susceptible population. Finally, conditions for avoiding a sudden and catastrophic jump in the number of individuals with antisocial behaviors are given.

Paléoécologie des foraminifères benthiques de nouvelles coupes de basse latitude du passage Crétacé-Paléogène : Coupes de l’Oued Es Smara et de l’Oued Abiod (région de Téjerouine, NW Tunisie)

Due to an impact of a bolide at the K/Pg boundary, the planktonic foraminifera have suffered sever mass extinction. However, no small Benthic Foraminifera species have documented mass extinction at the K/Pg boundary. Nevertheless, many species showed disturbance. The Maastrichtian assemblages may be different from those of the lower Paleogene by their species content, diversity and frequencies. At Oued Es Smara and Oued Abiod sections, the small benthic foraminifera indicate lower bathyal environment, and manifest significant faunal turnover. Until the uppermost Maastrichtian, their assemblages are highly diversified, with 77 species and 76 species respectively at Oued Es Smara and Oued Abiod sections. These are dominated by endobenthic morphotypes. At the K/Pg boundary, although 33 species (42,85%) (Oued Es Smara section) and 27 species (35,52%) (Oued Abiod section) of them seem to disappear, but only few species have really extinct such as Arenobulimina obesa. Nevertheless, the majority of species persist elsewhere at the Danian (e.g., Pseudoglandulina manifesta, Cibicioides proprius, Clavulinoides amorpha, Coryphostoma plaitum, Pullenia coryelli). At the lower Danian, the survivor Maastrichtian species are of 58% (Oued Es Smara) and 65% (Oued Abiod). Throughout the Parasubbotina pseudobulloides subzone, 4 others species were progressively disappeared. They are oligotrophic and low oxygen tolerant. About the Masstrichtian species, at the two studied sections (e.g. Gaudryina inflata and Tritaxia midwayensis) they seem to be more trophic exigent. Consequently, the benthic Foraminifera did not suffer massive extinction at the K/Pg boundary, but their assemblages underwent a significant faunal turnover which reflects important environmental changes. These changes are compatible with the catastrophic scenario induced by the large asteroid impact.

The Vaca Muerta transgression (Upper Jurassic), Neuquén Basin, Argentina: Insights into the evolution and timing of aeolian–marine transitions

AbstractConsidering the evolution of aeolian to marine transitions for the geological record, either catastrophic or gradual transgressive scenarios showing high or low rates of coastal migration have been proposed. A critical evaluation of modern analogues suggests that a catastrophic transgression shares many characteristics with Holocene transgressions, yet they are caused by different rates of sea‐level rise. The present study provides insights into the evolution of aeolian to marine transitions in order to discuss these alternative scenarios of sea‐level rise. For this purpose, a sedimentological and ichnological analysis was carried out on ten stratigraphic sections of the Picún Leufú area, Argentina. There, marine deposits of the Vaca Muerta Formation accumulated over the aeolian deposits of the Quebrada del Sapo Formation during the early Tithonian. The sedimentary evolution of the transition can be summarized in: (i) a shutdown of aeolian dune field deposition, generating a planation surface in somewhat elevated areas and reworked megadunes in lowlands; (ii) beach sedimentation caused by episodic marine flooding that contributed to megadune reworking; and (iii) deposition in an embayed marginal‐marine setting at the coast, recorded by bay margin bindstone, proximal bay and distal bay sedimentation. This transition indicates very rapid coastline migration and a condensed Transgressive Systems Tract succession throughout the study area. Rates of sea‐level rise similar to Holocene ones (millimetres to centimetres per year) may have produced the transition between the Quebrada del Sapo and Vaca Muerta formations. The Late Jurassic represents a non‐glacial time, and the global sea‐level maximum highstand pre‐dated the Vaca Muerta transgressive event. Thus, part of the sea‐level rise has to be attributed to tectonic/thermal subsidence and compaction of underlying strata, which may have generated these atypical rapid rates of sea‐level rise.