Climate-change resilience indicators for engineering infrastructure based on climatic tunnel simulation

Physical and logistical considerations of using ultrasonic anemometers in aeolian sediment transport research

Determination of erodible particles on cultivated soils by wind tunnel simulation

The recent changes in Australia’s climate, the likelihood of further changes over the next decades to centuries, and the likely significant impacts of these changes on the Australian livestock industries, provide increasing urgency to explore adaptation options more effectively. Climate and atmospheric changes are likely to impact on the quantity and reliability of forage production; forage quality; thermal stress on livestock; water demands for both animal needs and for growing forage; pest, disease and weed challenges; land degradation processes; and various social and economic aspects including trade. Potential adaptation options are available for moderate climate changes, with these often being variations of existing climate risk management strategies. However, to date there are few Australian examples where these adaptations have been assessed systematically on any scale (e.g. enterprise, regional, whole of industry or national). Nor have many studies been undertaken in a way that (i) effectively harness industry knowledge, (ii) undertake climate change analyses in the framework of existing operational systems, or (iii) assess climate change in the context of other socioeconomic or technical changes. It is likely that there are limits to the effectiveness of existing adaptations under more severe climate changes. In such cases more systemic changes in resource allocation need considering, such as targeted diversification of production systems and livelihoods. Dealing with the many barriers to effective adaptation will require ‘mainstreaming’ climate change into policies covering a range of scales, responsibilities and issues. This mainstreaming will facilitate the development of comprehensive, dynamic and long lasting policy solutions. The integrative nature of climate change problems requires science to include integrative elements in the search for solutions: a willingness to apply integrated rather than disciplinary science and a strengthening of the interface with decision-makers.

Mountain territories are the object of close attention of scientists due to the ongoing changes in the cryosphere. Altai is one of the world centers of glaciation, where climatic changes occur most intensively. The article presents the results of an interdisciplinary geographical and sociological study of climatic changes in the highlands of the Altai Republic, conducted in 2022 by scientists from Altai State University and St. Petersburg State University. On the basis of geological-landscape study on the reconstruction and cataloging of glaciers of the Little Ice Age and the forecast of dangerous exogenous processes, landscape changes and socio-economic parameters, settlements for sociological surveys were selected (six settlements of Kosh-Agach and Ulagan districts, n = 347). The research showed that glaciers of the North Chuysky Ridge have lost 61% of their area since the Little Ice Age, with 7% of the area reduced in the last 20 years. There have been qualitative changes in glacier melting - currently, large glaciers are experiencing the greatest degradation. The population of high-mountainous areas perceive climate change as significant, affecting their daily and economic life. Living near changing glaciers is associated with difficulties and additional costs for agriculture, destruction of communication and engineering infrastructure. Meanwhile, the climate agenda is not overly actualized, the population of high-mountainous areas demonstrates a high potential for adaptation, including due to traditional knowledge of nature management and living in harsh climates.

Tropical cyclones (TCs) are among the costliest natural hazards, posing significant risks to coastal communities worldwide. In the absence of additional adaptation measures, tropical cyclone damage is expected to increase significantly, i.a. due to rising sea surface temperatures that favor the formation of larger, more destructive tropical cyclones. The destructive potential of TCs is driven not only by extreme winds, but also by precipitation- and storm surge-induced flooding. To date, most impact models are based solely on modelled wind fields, meaning that other subhazards are only represented implicitly. This is particularly problematic given that climate change is expected to significantly increase TC-related rainfall and storm surge intensities. As a result, existing models may underestimate future TC risks.Building on previous event-based modeling approaches that assess TC-related economic losses based on wind fields, we present a novel multi-hazard damage function that integrates spatially explicit representations of wind, rain, and storm surge hazard. Our aim is to better understand the relative importance of TC subhazards and to identify loss drivers. In addition, the damage function can be applied in the attribution and projection of climate-change related costs. We calibrate damage functions based on U.S. county-level damage data from the Storm Events Database, socioeconomic data from the U.S. Census Bureau, and wind, rainfall and storm surge data modelled on a 30 arcsec grid. We test different functional forms and model specifications. Initial results indicate that all three subhazards have a statistically significant effect on TC damages and the inclusion of all three subhazards in the damage model improves its predictive power.

Intensity–duration–frequency (IDF) curves need to be reliable to serve as a relevant tool in preventing or reducing potential damage to society. This often requires accounting for the effect of climate change due to evidence of its effect on extreme precipitation. There is a large number of approaches for IDF curve estimation under climate change in the literature; however, a general framework with practical guidelines for facilitating their application by practitioners is not readily available. The aim of the present study is to provide practical guidelines and recommendations for helping federal and provincial agencies, as well as others who might produce practice guidelines, to develop standardized procedures for the estimation of future IDF curves in Canada that can then be used by practitioners in infrastructure design, management and risk assessment. This is done by gathering and summarizing findings in rainfall frequency analysis from the Canadian FloodNet Research Group, under a practically oriented perspective. Technical recommendations are presented within a methodological framework to facilitate understanding; decision-making procedure-specific flowcharts are provided to facilitate their application. The proposed methodological framework is based on the use of pooled frequency analysis for reasonable estimation of extreme rainfall intensities, and on the estimation of gridded relative changes for IDF updates under climate change following different approaches depending on rain gauge network density. In particular, three methods that do not compete against each other but rather are different methodologies to be applied depending on the case study are proposed: pooled estimation of extreme rainfall in Canada (Method I), gridded relative changes in 24-h extreme rainfall intensities in Canada (Method II) and gridded relative changes in 24-h and sub-daily extreme rainfall intensities in regions of Canada with a relatively high station density (Method III).

Assessing climate change risk: An index proposal for Mexico City

Externally slung loads and their mission applications are becoming more common on human and autonomously piloted air vehicles. Flight speed is often limited not by the performance envelope but by the danger of divergent load oscillations. Certifying this limiting speed for every load-vehicle combination, is a huge barrier to operations. The conservatism dictated by this uncertainty may itself be life-threatening in critical applications. Computing the dynamics of slung loads for a specific load/vehicle combination has been hindered by lack of knowledge on bluffbody aeromechanics. The prevailing top-down approach is to incorporate slung load aeromechanics calculations into large comprehensive aeromechanics codes for rotorcraft. We argue for a bottom-up approach. This allows on-the-fly system identification and dynamics simulation. The Slung Load Amplification Detector (SLAD) concept provides an on-board safety system to predict, detect, avoid and alleviate divergent oscillations. SLAD is based on a knowledge base derived from wind tunnel data and simulation results including canonical geometries, as well as practical shapes. Validation of simulation results against two practical test cases lends confidence. SLAD allows reliable distinction between pseudo and absolute divergence, permitting an increase of as much as 50% speed in safe flight speed, and guidance on active alleviation of oscillations.

Understanding Flow Patterns At Street Canyon Intersections Using Wind Tunnel And CFD Simulations

LAS Doppler Velocimetry in a Hypersonic Wind Tunnel and 1D Non-Equilibrium Nozzle Simulations

This study aims to identify lower risk exterior shelter areas and building air intake locations by modeling particulate matter (PM) dispersion in a three-dimensional street canyon from a point source and comprises a wind tunnel experiment and a computational fluid dynamics (CFD) simulation. The model street canyon was a two-by-two building array of constant height with aspect ratios of 0.35, 0.70, and 1.05. A PM emission source external to the street canyon was simulated with water droplets from an ultrasonic humidifier in the wind tunnel. The CFD simulation, using the standard turbulence k-ϵ turbulence model and the Discrete Phase Model, showed that, inside the street canyon, the sidewalks had the lowest PM concentration at the breathing level of 1.5 m above the ground. Regardless of wind direction and PM source location, the roofs had the lowest PM concentration among all building surfaces with access to the internal intersection. Therefore, if an accidental point release of PM outside the street canyons occurs, pedestrians that could not enter buildings should stay on the sidewalks. For building construction and renovation, new ventilation air intakes should be installed on the roofs, and the intakes that are already installed on other building façade surfaces should be advised to be closed during such episode.

The present review deals with the current scientific knowledge related with ski jump landing. A specific focus is given on the landing biomechanics, the methods utilized for its analysis and the injuries connected to the landing phase. Despite the demonstrated importance for the safety and the performance of ski jumpers, the landing and its preparation are rarely investigated. In this paper, after having firstly described the execution of landing and its preparation and the reason why is important to analyze it, an overview of the current status of the research related to the landing biomechanics is reported (kinetics, kinematics, electromyographic activation, aerodynamics, computer simulation). The third part describes the methods and technologies utilized in literature to analyze the landing and its preparation (video cameras, inertial sensors, force insoles, wind tunnel and computer simulation). After that, an overview of the injuries related to landing is reported. The final section proposes future research in the field of biomechanics of ski jump landing in different fields, such as computer simulations, kinematic analysis, equipment development and biomechanics of female athletes.

As part of a project to determine ship air wake impact on naval rotary wing vehicles, this paper compares wind tunnel and computational fluid dynamics (CFD) simulations with in situ data that has been collected on an instrumented United States Naval Academy (USNA) YP (Patrol Craft, Training). The in situ data has been collected underway on a vessel which is 108 ft long and has a 24 ft above water line height. The wind tunnel data is from a 4% scale model tested in the USNA 42 × 60 × 120 inch wind tunnel. CFD simulations were performed on a 15.5 million tetrahedral unstructured grid. Data from the three sources is compared over 11 vertical and horizontal planes above the flight deck on the stern section of the YP. Data is compared for a head wind condition and for relative wind 15° off the starboard bow. Good comparison in velocity direction, typically less than 10-15°, is observed in the vertical and horizontal planes. Normalized velocity magnitudes do not compare as well, likely arising from the lack of an atmospheric boundary layer modeled in CFD simulations and wind tunnel testing.

Structural monitoring of an instrumented experimental single-storey wood building provided important information regarding the behaviour and response of low-rise buildings subjected to wind loads. Foundation wind-induced loads were captured by twenty-seven three-dimensional load cells simultaneously with the envelope pressures and weather characteristics. The distribution of the total wind load to each wall is examined and normalized to the wind speed for each direction. The correlation between loads acting on different wall segments is also quantified in the form of participation factors. In parallel with full-scale findings, a scaled model of the experimental building and its surroundings is tested in a boundary layer wind tunnel. The detailed pressure distribution information for thirty-six wind angles of attack obtained through three different upstream terrain simulations is used to generate expected total uplift wind force. The findings are compared to data acquired directly from the foundation load cells located in the test house. The comparison revealed that in most cases wind tunnel values are within the range of the field results. Discrepancies are somewhat higher for wind tunnel tests conducted using the open/suburban terrain compared to the urban terrain simulation. The results are significant for the improvement of the wind tunnel testing and simulation procedures, for the development of code and standard provisions, as well as for the verification of the finite element numerical model of the test house.

The resilience of critical infrastructure is a crucial component of national security and state development. The dependence of modern societies on the effective functioning of such objects as energy systems, transportation, communications, water supply, and other vital infrastructure necessitates ensuring their resilience to various threats. The levels of criticality have been identified, and a distribution of infrastructure objects based on their criticality criteria has been proposed. The article defines the main factors that influence the resilience of critical infrastructure, including vulnerability, risks, recovery mechanisms, adaptability, security, social and economic aspects, as well as the role of intersectoral coordination. The importance of flexibility and adaptability in crisis situations is highlighted for the rapid restoration of infrastructure functioning after catastrophic events, whether natural, technological, or terrorist attacks. One of the key areas identified is the study of critical infrastructure resilience assessment, based on a multi-factor approach that includes the analysis of both technical and social aspects. Among the most important factors influencing infrastructure resilience are the development of cybersecurity technologies, the adequacy of legal norms, and the capacity for infrastructure to adapt to new threats. Taking these factors into account not only allows for assessing the current level of infrastructure resilience but also helps identify the most vulnerable areas that require enhanced protection and timely intervention. The identification of recovery and adaptation mechanisms is a critical aspect for ensuring the continuous functioning of critical systems during emergencies. The article also presents possible directions for resilience assessment that contribute to more accurate forecasting of potential risks and the development of effective strategies to ensure the stability of critical infrastructure objects. The conclusion emphasizes the importance of a differentiated approach to developing resilience measures based on the criticality criteria of the respective infrastructure objects.