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Insight into coral reef ecosystems: investigations into the application of acoustics to monitor coral reefs and how corallivorous fish respond to mass coral mortality.Dimoff, Sean 05 February 2021 (has links)
Coral reefs around the world are threatened by a variety of sources, from localized impacts, including overfishing and coastal development, to global temperature increases and ocean acidification. Conserving these marine biodiversity havens requires both global and local action informed by scientific research. In this thesis, I use data collected from the coral reefs around Kiritimati atoll (Republic of Kiribati) in the central equatorial Pacific, first to assess the applicability of two common metrics used in passive underwater acoustic research, and second to examine the effects of a marine heatwave and local human disturbance on an assemblage of corallivorous fish. Using acoustic data recorded in 2017 and 2018 on reefs around Kiritimati, I assess how sound pressure level (SPL) and the acoustic complexity index (ACI) respond to changes in fish sounds in a low frequency band (160 Hz – 1 kHz) and snapping shrimp snaps in a high frequency band (1 kHz – 22 kHz). I found that while SPL was positively correlated with increases in fish sounds and snap density, changes in ACI were dependent upon the settings chosen for its calculation, with the density of snaps negatively correlated with ACI across all settings. These findings provide evidence that despite its quick and prolific adoption, acoustic metrics like ACI should be thoroughly field-tested and standardized before they are applied to new ecosystems like coral reefs. Next, using underwater visual censuses (UVCs) of reef fish assemblages, I quantified how two functional groups of corallivores, obligate and facultative, responded to a mass coral mortality event created by the 2015-2016 El Niño. Declines in abundance of both groups were largely driven by the response of coral-associated damselfishes, Plectroglyphidodon johnstonianus in the obligate group and Plectroglyphidodon dickii in the facultative group, to heat stress and subsequent coral mortality. I also observed a significant decline in the species richness of obligate corallivores, and a continued decline in the abundance of obligate corallivores three years after the mass coral mortality event. Additionally, facultative corallivore abundance increased with disturbance, although the effect was modulated by year, likely due to their more adaptable diets. Corallivore assemblage structure was also influenced by the heat stress event, recovery, and local human disturbance. These results detail how an entire corallivorous assemblage is impacted by a coral mortality event and incidentally provide a timeline for corallivore decline. Together, these results provide information about new ways of monitoring coral reefs, and the ways in which two components of the reef fish community, obligate and facultative corallivores, respond to a mass coral mortality event. / Graduate / 2022-01-15
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Känslighet och anpassningsförmåga inför värmeböljor i Östergötland : En studie om klimatrelaterad sårbarhet / Sensitivity and adaptive capacity to heat waves in Östergötland : A study about climate-related vulnerabilityBerg, Sara, William-Olsson, Julia January 2021 (has links)
Värmeböljor i Östergötland förväntas bli mer frekvent förekommande och med en större intensitet. Klimat- och sårbarhetsanalyser används som underlag för klimatanpassningen i länet, men det saknas en enhetlig definition av vad klimatrelaterad sårbarhet innebär. Dagens sårbarhetsanalyser för Östergötland fokuserar på utsattheten för olika klimatförändringsaspekter. Denna studie syftar till att undersöka sårbarhet inför värmeböljor i Östergötland utifrån känslighet och anpassningsförmåga och att sätta det i relation till gällande styrdokument för klimatanpassning. Studien görs via karteringar över Östergötlands biofysiska känslighet och socioekonomiska anpassningsförmåga som sedan kompletteras med en tematisk dokumentanalys av några av länets plandokument. Karteringen visar hur känsligheten är koncentrerad i stadskärnorna medan låg anpassningsförmåga snarare är utspridd över stadsdelarna. Temana som tas upp och diskuteras utifrån dokumenten är strategi, behov, känslighet och anpassningsförmåga. Dokumentanalysen visar på en otydlighet samt vissa motsägelser mellan styrdokumenten vilket indikerar att Länsstyrelsen brister i sin roll som samordnande organ inom klimatanpassningen i länet. / Heatwaves in Östergötland are expected to appear more frequently and intensify. Climate and vulnerability assessments are used as the basis of climate adaptation in the region, but there is a lack of a standardized definition of climate related vulnerability. This study aims to assess the vulnerability to heatwaves in Östergötland based on sensitivity and adaptive capacity, to put in relation to current policy and planning documents for climate adaptation in the region. The study is conducted by mapping the bio-physical sensitivity and the socio-economic adaptive capacity with a complementary thematic analysis of the regions policy and planning documents. The mapping shows that high sensitivity and low adaptive capacity mainly occurs within and around the urban areas of Linköping and Norrköping. The thematic analysis demonstrates an ambiguity within the policy documents and the conclusion is that Länsstyrelsen Östergötland fails in its role as a coordinator of climate adaptation in the region.
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Multi-risk modeling for improved agriculture decision-support: predicting crop yield variability and gaps due to climate variability, extreme events, and diseaseLu, Weixun 15 September 2020 (has links)
The agriculture sectors in Canada are highly vulnerable to a wide range of inter-related weather risks linked to seasonal climate variability (e.g., El Ni ̃no Southern Oscillation(ENSO)), short-term extreme weather events (e.g., heatwaves), and emergent disease(e.g., grape powdery mildew). All of these weather-related risks can cause severe crop losses to agricultural crop yield and crop quality as Canada grows a wide range of farm products, and the changing weather conditions mainly drive farming practices. This dissertation presents three machine learning-based statistical models to assess the weather risks on the Canadian agriculture regions and to provide reliable risk forecasting to improve the decision-making of Canadian agricultural producers in farming practices. The first study presents a multi-scale, cluster-based Principal Component Analysis(PCA) approach to assess the potential seasonal impacts of ENSO to spring wheat and barley on agricultural census regions across the Canada prairies areas. Model prediction skills for annual wheat and barley yield have examined in multi-scale from spatial cluster approaches. The ’best’ spatial models were used to define spatial patterns of ENSO forcing on wheat and barley yields. The model comparison of our spatial model to non-spatial models shows spatial clustering and ENSO forcing have increase model performance of prediction skills in forecasting future cereal crop production. The second study presents a copula-Bayesian network approach to assess the impact of extreme high-temperature events (heatwave events) on the developments of regional crops across the Canada agricultural regions at the eco-district-scale. Relevantweather variables and heatwave variables during heatwave periods have identified and used as input variables for model learning. Both a copula-Bayesian network and Gaussian-based network modeling approach is evaluated and inter-compared. The copula approach based on ’vine copulas’ generated the most accurate predictions of heatwave occurrence as a driver of crop heat stress. The last study presents a stochastic, hybrid-Bayesian machine-learning approach to explore the complex causal relationships between weather, pathogen, and host for grape powdery mildew in an experimental farm in Quebec, Canada. This study explores a high-performance network model for daily disease risk forecast by using estimated development factors of pathogen and host from recorded daily weather variables. A fungicide strategy for disease control has presented by using the model outputs and forecasted future weather variability. The dissertation findings are beneficial to Canada’s agricultural sector. The inter-related weather risks explored by the three separate studies in multi-scales provide a better understanding of the interactions between changing weather conditions, extreme weather, and crop production. The research showcases new insights, methods, and tools for minimizing risk in agricultural decision-making / Graduate / 2021-08-19
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Adapting Properties to Climate Risks and its Financial Impact and EU Compliance : Case Study on a Real Estate Company / Anpassning av fastigheter till klimatrisker och dess ekonomiska konsekvenser samt EU-kompatibilitet : En fallstudie av ett fastighetsbolagChienh, Jennifer, Mian, Ozair January 2024 (has links)
As climate change progresses, extreme weather events such as heatwaves, heavy rainfall, and flooding are expected to become more common and frequent. Increased climate-related risks pose multiple threats to society, including damage to properties and infrastructure, loss of human lives, and economic instability. This necessitates property owners to adapt to future climate scenarios. To direct capital towards sustainable investments and contribute to a green transition, the EU has introduced measures such as the EU Taxonomy, and the Corporate Sustainability Reporting Directive (CSRD), which an increasing number of companies will gradually be covered by. Many companies are unprepared for the growing demands of the CSRD, which must be reported according to the European Sustainability Reporting Standards (ESRS). The purpose of this report is to identify the climate-related risks faced by real estate companies, focusing on properties for public use, and to highlight the economic consequences of these risks. Furthermore, the report aims to contribute to the development of methods for ongoing management of climate risks, including prioritization and action planning, as well as exploring how real estate companies can integrate climate adaptation in line with ESRS. The development of the model for climate and vulnerability analyses is based on previous analyses conducted by various actors and adapted to ESRS. Semi-structured interviews have been conducted with industry players to gain insight into how the work on climate adaptation of properties is progressing and its financial impact. To investigate how market value can be affected by preventive climate adaptation measures compared to post-climate event costs, a Discounted Cash Flow Analysis was performed. A five-step model has been developed, including: mapping of the property portfolio, identifying climate-related risks, risk analysis and property-specific characteristics, risk assessment, and implementation of climate adaptation measures. Investments in climate adaptation measures are cheaper in the long run than not adapting, as the costs of damage are often much higher and have a more negative impact on property values. The work on climate adaptation is an ongoing process, and sustainability reporting according to CSRD is complex. Insurance companies only compensate for damages classified as "unforeseen and sudden." This means that properties need to be climate-adapted to be insurable. Without insurance protection, it also becomes difficult to obtain bank loans, as properties are often used as collateral. / I takt med klimatförändringarna förväntas extremväder som värmeböljor, skyfall och översvämningar bli allt vanligare och mer frekventa. Ökade klimatrelaterade risker hotar samhället på många sätt, såsom skador på fastigheter och infrastruktur, människoliv och ekonomisk stabilitet. Vilket ställer krav på fastighetsägare att klimatanpassa utifrån framtida klimatscenarier. För att styra kapital mot hållbara investeringar och bidra till en grön omställning har EU bland annat infört EU-taxonomin, och Corporate Sustainabilty Reporting Directive (CSRD), som allt fler företag successivt kommer att omfattas av. Många företag är inte förberedda på de ökande kraven från CSRD som ska redovisas enligt European Sustainability Reporting Standards (ESRS). Syftet med rapporten är att identifiera klimatrelaterade risker som fastighetsbolag, med fokus på samhällsfastigheter, står inför samt att belysa de ekonomiska konsekvenserna av dessa risker. Vidare syftar rapporten till att bidra till utvecklingen av metoder för löpande hantering av klimatrisker, inklusive prioritering och åtgärdsplanering, samt att undersöka hur fastighetsbolag kan integrera klimatanpassning i linje med ESRS. Utvecklingen av modellen för klimat- och sårbarhetsanalyser baseras på tidigare analyser utförda av olika aktörer samt anpassning till ESRS. Semi-strukturerade intervjuer har genomförts med branschaktörer för att få en inblick i hur arbetet med klimatanpassning av fastigheter pågår och dess finansiella påverkan. För att undersöka hur marknadsvärdet kan påverkas av förebyggande klimatanpassningsåtgärder jämfört med kostnader efter en klimathändelse, genomfördes en kassaflödesanalys (Discounted Cashflow Analysis). En 5-stegsmodell har utvecklats som inkluderar: kartläggning av fastighetsbeståndet, identifiering av klimatrelaterade risker, riskanalys och fastighetsspecifika egenskaper, riskbedömning samt implementering av klimatanpassningsåtgärder. Investeringar i klimatanpassningsåtgärder är billigare i längden än att inte klimatanpassa, eftersom kostnaderna för skador ofta är mycket högre och påverkar fastighetsvärdet mer negativt. Arbetet med klimatanpassning är en pågående process, och hållbarhetsrapportering enligt CSRD är komplicerat. Försäkringsbolag ersätter endast skador som klassas som ” plötsliga och oförutsedda”. Detta innebär att fastigheter behöver klimatanpassas för att vara kunna försäkras. Utan försäkringsskydd blir det dessutom svårt att få banklån, då fastigheter ofta används som säkerhet.
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Etudes pharmaco-épidémiologiques des neuroleptiques chez les sujets âgés et les patients souffrant de schizophrénie / Pharmaco-epidemiology studies of antipsychotic drugs in elderly people and schizophrenia patientsNordon, Clémentine 06 March 2013 (has links)
Contexte : Les neuroleptiques sont souvent prescrits chez les sujets âgés et les patients souffrant de schizophrénie qui sont des personnes vulnérables. Notre objectif était d’étudier l’impact des NLP en situation réelle de prescription, dans ces deux populations. Etude 1. Consommation de neuroleptiques et décès en période de canicule chez les sujets âgés. A partir de données de l’Assurance Maladie, nous avons comparé les prescriptions de NLP chez des sujets âgés décédés pendant la canicule d’août 2003 (n=11624) aux prescriptions de témoins non décédés. Nous avons mis en évidence une association entre risque de décès et consommation de neuroleptiques, que ce soit juste avant ou pendant le pic de canicule et indépendamment d’autres médicaments, d’une démence ou d’une pathologie cardiaque. Etude 2. Efficacité réelle des NLP chez les patients souffrant de schizophrénie. A partir de données d’une cohorte observationnelle ayant inclus en France entière des schizophrènes adultes, nous avons montré que chez les patients déjà traités par NLP (n=5500), il y avait une association entre traitement par antipsychotique atypique (vs. NLP classique) et une meilleure satisfaction avec les soins et ce, pour tous les AA pris en compte et indépendamment du niveau de symptomatologie. Par ailleurs, chez les patients naïfs vis-à-vis de tout NLP et pour qui un traitement était introduit pour la première fois (n=467), un tiers des patients ne s’améliorait pas. Les facteurs prédictifs d’une meilleure réponse clinique étaient une moindre sévérité initiale globale des symptômes et des symptômes négatifs de schizophrénie. Au total, il existait cinq types de trajectoires d’évolution clinique. / Context : Antipsychotic drugs (AD) are often prescribed to elderly people and patients with schizophrenia and both populations are fragile. The aim of the present thesis was to investigate the impact of AD in these patients, in a real-life setting. Study 1. Antipsychotic drug use during a heatwave and risk of death, in older people. Using data from the French Social Security, prescriptions of older people who died during the heatwave in August 2003 (n=11624) were compared to these of controls who survived. An association was evidenced between a prescription of AD and death, in the periods just preceding and during the heatwave, independently of other psychotropic drugs, dementia or cardiac disease. Study 2. Effectiveness of AD in schizophrenia patients. Using data from a French nationwide observational study, we found that in patients treated for schizophrenia (n=5500), a higher level of satisfaction was independently associated with being on second-generation AD as compared to first-generation AD. Also, in drug-naive patients (n=467) followed up during 6 months after a first AD initiation, one third of the patients did not experience any improvement of symptoms. The factors predictive of a better clinical response were lower levels of baseline negative symptoms and overall severity of symptoms. A total of 5 trajectories of clinical evolution were identified.
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