scholarly journals From Theory to Field Evidence: Observations on the Evolution of the Settlements of an Earthfill Dam, over Long Time Scales

2019 ◽  
Vol 4 (4) ◽  
pp. 65 ◽  
Author(s):  
Pytharouli ◽  
Michalis ◽  
Raftopoulos
Keyword(s):  
Extreme Weather Events ◽  
Field Evidence ◽  
Weather Events ◽  
Long Time ◽  
Clay Core ◽  
Earthfill Dams ◽  
Downstream Communities ◽  
Flooding Events ◽  
First Time

Unprecedented flooding events put dams and downstream communities at risk, as evidenced by the recent cases of the Oroville and Whaley bridge dams. Empirical models may describe expected ‘normal’ dam behaviour, but they do not account for changes due to recurring extreme weather events. Numerical modelling provides insights into this, but results are affected by the chosen material properties. Long-term field monitoring data can help with understanding the mechanical behaviour of earthfill dams and how this is affected by the environment over decades. We analyse the recorded settlements for one of the largest earthfill dams in Europe. We compare the evolution of these settlements to the reservoir level, rainfall, and the occurrence of earthquakes for a period of 31 years after first impoundment. We find that the clay core responds to the reservoir fluctuations with an increasing (from 0 to 6 months) time delay. This is the first time that a change in the behaviour of a central clay core dam, as observed from field data, is reported in the international literature. Seepage rates, as recorded within the drainage galleries, are directly affected by cumulative rainfall depths exceeding 67 mm per fortnight.

scholarly journals Assessing the impacts of extreme weather events on potable water quality: the value to managers of a highly participatory, integrated modelling approach

2018 ◽  
Vol 2 (1) ◽  
pp. 9-24
Author(s):  
Edoardo Bertone ◽  
Oz Sahin ◽  
Russell Richards ◽  
Anne Roiko
Keyword(s):  
Water Quality ◽  
Decision Support ◽  
Extreme Events ◽  
Drinking Water Treatment ◽  
Extreme Weather ◽  
Integrated Modelling ◽  
Extreme Weather Events ◽  
Weather Events ◽  
Sd Model

Abstract A decision support tool was created to estimate the treatment efficiency of an Australian drinking water treatment system based on different combinations of extreme weather events and long-term changes. To deal with uncertainties, missing data, and nonlinear behaviours, a Bayesian network (BN) was coupled with a system dynamics (SD) model. The preliminary conceptual structures of these models were developed through stakeholders' consultation. The BN model could rank extreme events, and combinations of them, based on the severity of their impact on health-related water quality. The SD model, in turn, was used to run a long-term estimation of extreme events' impacts by including temporal factors such as increased water demand and customer feedback. The integration of the two models was performed through a combined Monte Carlo–fuzzy logic approach which allowed to take the BN's outputs as inputs for the SD model. The final product is a participatory, multidisciplinary decision support system allowing for robust, sustainable long-term water resources management under uncertain conditions for a specific location.

scholarly journals THE ECONOMICS OF DISASTER RISK AND RECOVERY:  THREE ESSAYS ON SRI LANKA

2021 ◽  
Author(s):  
◽  
Diana de Alwis
Keyword(s):  
Health Care ◽  
Land Use ◽  
Sri Lanka ◽  
Food Consumption ◽  
Health Risks ◽  
Household Income ◽  
Disaster Risk ◽  
Extreme Weather Events ◽  
Weather Events

<p>Dramatic increase of economic losses from Natural disasters derail economic and human development in many places. This dissertation sheds light on natural disaster risk and short-term and long-term household wellbeing after disasters. It is composed of three empirical studies of Sri Lanka. The first study examines the impacts of frequently occurring extreme weather events on individual health and health care cost using national household data. The analysis shows that local floods and droughts impose a significant risk to health when individuals are exposed directly and their communities indirectly to these hazards. These risks are associated with the land-use in the affected regions and the status of access to sanitation and hygiene. Health risks due to flood and drought cause a considerable economic burden on the private and public health care sectors. Finally, we learn that recurring extreme weather events may potentially be sources of significant health risk and economic cost to a rapidly growing developing country that call for alternative policies focusing on the socio-economic environment, and land use to manage these health risks. The second study estimates a difference- in- difference (DID) model to examine the 2004 Indian Ocean tsunami’s long-term impacts on household wellbeing in Sri Lanka. The study finds a strong association between area-wide tsunami disaster shock and increases in household income and consumption in the long-term. The increase in consumption is much smaller than the observed increase in income; the study reveals an increase in food consumption and only a marginal increase in non-food consumption. The third study analyses the 2004 tsunami recovery’s impact on income distribution across households in the long-term in Sri Lanka using quantile difference-in-difference methods and inequality measures. Recovery of household income is observed across the entire distribution of affected households. The income recovery is skewed to low-income households; the affected regions appear more income-equal ex-post compared to the unaffected regions. A similar pattern appears for consumption. Finally, the findings in the second and third studies show a potential for a long-lasting and successful recovery from a catastrophic disaster.</p>

scholarly journals Perfect Storm: Climate Change and Tourism

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Serhan Cevik ◽  
Manuk Ghazanchyan
Keyword(s):  
Climate Change ◽  
Extreme Weather Events ◽  
International Tourism ◽  
Weather Events ◽  
Negative Effect ◽  
Climate Vulnerability ◽  
The Caribbean ◽  
Long Term Impact ◽  
Perfect Storm

Abstract While the world’s attention is on dealing with the COVID-19 pandemic, climate change remains a greater existential threat to vulnerable countries that are highly dependent on a weather-sensitive sector like tourism. Using a multidimensional index, this study investigates the long-term impact of climate change vulnerability on international tourism in a panel of 15 Caribbean countries over the period 1995–2017. Empirical results show that climate vulnerability already has a statistically and economically significant negative effect on international tourism revenues across the region. As extreme weather events are becoming more frequent and severe over time, our findings indicate that the Caribbean countries need to invest more in adaptation and mitigation in order to reduce vulnerabilities.

scholarly journals Perfect Storm

2020 ◽  
Vol 20 (243) ◽  
Author(s):  
Serhan Cevik ◽  
Manuk Ghazanchyan
Keyword(s):  
Climate Change ◽  
Extreme Weather Events ◽  
International Tourism ◽  
Weather Events ◽  
Negative Effect ◽  
Adaptation Policies ◽  
Climate Vulnerability ◽  
The Caribbean ◽  
Long Term Impact

While the world’s attention is on dealing with the COVID-19 pandemic, climate change remains a greater existential threat to vulnerable countries that are highly dependent on a weather-sensitive sector like tourism. Using a novel multidimensional index, this study investigates the long-term impact of climate change vulnerability on international tourism in a panel of 15 Caribbean countries over the period 1995–2017. Empirical results show that climate vulnerability already has a statistically and economically significant negative effect on international tourism revenues across the region. As extreme weather events are becoming more frequent and severe over time, our findings indicate that the Caribbean countries need to pursue comprehensive adaptation policies to reduce vulnerabilities to climate change.

Challenges and Future Directions in Ocean Wave Modeling — A Review

2019 ◽  
Vol 06 (02) ◽  
pp. 1950004 ◽  
Author(s):  
Prasad K. Bhaskaran
Keyword(s):  
Climate Change ◽  
Numerical Models ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Future Directions ◽  
Wave Modeling ◽  
Weather Events ◽  
Recent Developments ◽  
Flooding Events ◽  
Global Oceans

An increasing number of instances in extreme weather events over the global oceans have deepened the concerns on the impact of climate change. The frequency of extreme weather events is also seen to increase attributes to climate change across the globe. In the Indian context, there has been about 285 reported flooding events over the period from 1950 to 2017 that affected nearly 850 million people with many causalities. As the global oceans become stormier, the effects are seen in rising sea level and infrastructural facilities. Major flooding events are caused by tropical cyclone-induced storm surge and associated breaking waves. These extreme weather events coupled with sea level rise have serious repercussions on the coastal vulnerability. Also recently, there is an upsurge in the intensity and tropical cyclone size that forms over the North Indian Ocean region that brought attention among the scientific community. The worst possible scenario of extreme water level can occur when the time of storm surge occurrence coincides with the astronomical high water. This review paper provides a comprehensive overview on the research developments and efforts made in ocean wave modeling in particular for the Indian seas. As per the Fifth Assessment Report of Intergovernmental Panel on Climate Change (IPCC), the role and influence of ocean surface gravity wave in the climate system are considered to be very important. At present, numerical models are widely used and that can be used to hindcast and forecast the wave characteristics over both regional and global ocean basin scales. A detailed overview on the observational techniques is listed along with the historical perspective and recent developments in wind-wave modeling for the Indian seas. Recent developments in computing technology and advanced numerical techniques have made it possible to solve the complex problems in coastal science and engineering using state-of-the-art numerical models providing realistic estimates, cost effective and having immense potential in operational weather centers. This review also deals with some of the important issues and future directions in wind-wave modeling studies such as improvements required in momentum transfer, bottom dissipation, and rain–wave interaction effects that require detailed understanding and concentrated efforts.

The CO2 balance of a boreal fen is more sensitive to drought than surrounding forests

2020 ◽  
Author(s):  
Mats Nilsson ◽  
Joshua Ratcliffe ◽  
Anne Klosterhalfen ◽  
Peng Zhao ◽  
Jinchu Chi ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Vapour Pressure Deficit ◽  
Weather Conditions ◽  
Pine Forest ◽  
Extreme Weather Events ◽  
Boreal Peatlands ◽  
Weather Events ◽  
Co2 Balance ◽  
First Time ◽  
Boreal Landscape

&lt;p&gt;The boreal zone is one of the most carbon-dense biomes in the world and is comprised of a highly interconnected mosaic of forest and wetlands which are warming at a rate several times the global average with extreme weather events, such as droughts, becoming increasingly common. At the ecosystem scale, both forests and peatlands are often vulnerable to drought-induced carbon loss, however, the relative resilience of these two ecosystems within the boreal landscape is not well understood. Here we study the effect of the 2018 drought on CO&lt;sub&gt;2&lt;/sub&gt; fluxes in two boreal forests and a boreal peatland within &lt;20km radius, i.e. experiencing the same weather conditions. The peatland displayed the strongest response to the drought, with the site becoming a net annual source for CO&lt;sub&gt;2&lt;/sub&gt; for the first time in 17 years, with the CO&lt;sub&gt;2 &lt;/sub&gt;sink slow to recover after the drought broke. In contrast, the response of the forests was mixed, a&amp;#160; spruce/pine forest on glacial till remained unaffected by the drought, whereas a nearby pine forest, situated on drier sandy soil, responded strongly to vapour pressure deficit and declining soil moisture content, decreasing with CO&lt;sub&gt;2&lt;/sub&gt; uptake weakening, but still allowing the forest to function as a CO&lt;sub&gt;2&lt;/sub&gt; sink. In contrast to the bog, the pine forest CO&lt;sub&gt;2&lt;/sub&gt; sink quickly recovered following the end of the drought. We conclude that boreal peatlands are likely to be the most vulnerable component of the boreal landscape to drought and that soil type is likely to play a role in regulating the response of boreal forests.&lt;/p&gt;

scholarly journals Understanding Mesoscopic Chemo-Mechanical Distress and Mitigation Mechanisms of Concrete Subject to ASR

2020 ◽  
Author(s):  
Md Asif Rahman
Keyword(s):  
Global Warming ◽  
Service Life ◽  
Mechanical Damage ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Alkali Silica Reaction ◽  
Weather Events ◽  
Temperature And Humidity ◽  
Concrete Damage

Alkali-silica reaction (ASR) is one of the common sources of concrete damage worldwide. The surrounding environment, namely, temperature and humidity greatly influence the alkali-silica reaction induced expansion. Global warming (GW) has caused frequent change in the climate and initiated extreme weather events in recent years. These extreme events anticipate random change in temperature and humidity, and convey potential threats to the concrete infrastructure. Moreover, external loading conditions also affect the service life of concrete. Thus, complex mechanisms of ASR under the impact of seasonal change and global warming require a precise quantitative assessment to guide the durable infrastructure materials design practices. Despite decades of phenological observation study, the expansion behavior of ASR under these situations remains to be understood for capturing the ASR damage properly. Within this context this research focuses on the mathematical model development to quantify and mitigate ASR-induced damage. Mesoscale characteristics of ASR concrete was captured in the virtual cement-concrete lab where the ASR gel-induced expansion zone was added as a uniform thickness shell. Finite element method (FEM) was used to solve the ASR formation and expansion evolution. The results of this study are presented in the form of one conference and their journal manuscripts. The first manuscript focuses on the development of the governing equations based on the chemical formulas of alkali-silica reaction to account for the ASR kinetics and swelling pressure exerted by the ASR expansion. There is a fluid flow and mass transfer in the concrete domain due to ASR gel associated from ASR kinetics. This paper involves derivation of the mass and momentum balance equation in terms of the thermo-hygro-mechanical (THM) model. THM model accounts for thermal expansion and hygroscopic swelling in addition to traffic loads to represent volumetric change in the concrete domain. The second manuscript is a case study based on different cement-aggregate proportions and alkali hydroxide concentrations. It is important to know how ASR evolves under variable concentration of the chemical species. The simulated results show that high concentration of hydroxide ion in concrete initiates more reaction and damage in concrete. Also chemical reaction moves to the right direction with low cement to aggregate ratio which means ASR expansion depends on the availability of the reactive aggregates in the concrete domain. The third manuscript attempts to develop a simplified ASR model that integrates chemo-physio-mechanical damage under stochastic weather impact. Stochasicity incorporates the random behavior of surrounding nature in the model. The simulated results elucidate that ASR expansion is more severe under the influence of global warming and climate change. This will support long-term damage forecasts of concrete subjected to extreme weather events. The fourth manuscript focuses on the quantification of mechanical damage under ASR expansion and a dedicated mitigation scheme to minimize it. Added creep loads and physics identify the role of creep damage on ASR expansion. The results from this paper confirms that the ASR-induced damage significantly minimize the load carrying capacity of concrete. It directly affects the compressive strength, tensile strength, and modulus of elasticity of concrete. Damage in aggregates domain is more than the mortar phase under the creep loadings. Among many supplementary materials, fly ash is the most effective in minimizing ASR expansion and damage. This work also includes a petrographic comparison between different mineral types collected from different locations to identify the reactivity of certain aggregates. Thus, the final outcome of this research is a complete model which is a conclusive solution to the long-term ASR damage prediction. The validated model provides better understanding of ASR kinetics from mesoscale perspective. The developed model can potentially accelerate the precise prediction of concrete service life and mitigation schemes as well as can be used as an alternative scope to the costly laboratory tests methods.

scholarly journals Sport and climate change—how will climate change affect sport?

2021 ◽  
Author(s):  
Sven Schneider ◽  
Hans-Guido Mücke
Keyword(s):  
Climate Change ◽  
Health Risks ◽  
Extreme Temperature ◽  
Extreme Weather Events ◽  
Sports Organizations ◽  
Sports Science ◽  
Weather Events ◽  
Health Related ◽  
Induced Changes ◽  
First Time

AbstractClimate change will have complex consequences for the environment, society, economy and people’s health. The issue of climate change has received comparatively little attention to date in the fields of sports science. Thus, sport-related health risks caused by climate change are discussed and summarized in a conceptual model presented here for the first time. Climate change is associated with the following increases of health-related risks for athletes in particular: Direct consequences caused by extreme temperature and other extreme weather events (e.g. increasing risks due to heatwaves, thunderstorms, floods, lightning, ultraviolet radiation) and indirect consequences as a result of climate-induced changes to our ecosystem (e.g. due to increased air pollution by ozone, higher exposures to allergens, increasing risks of infection by viruses and bacteria and the associated vectors and reservoir organisms). Each aspect is supplemented with advice on the prevention of health hazards. Not only individual athletes but also sports organizations and local clubs will have to respond to the changes in our climate, so that they can appropriately protect both athletes and spectators and ensure a plannable continuation of the sport in the future.

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