Letteratura scientifica selezionata sul tema "Drought events"
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Articoli di riviste sul tema "Drought events":
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Van Loon, A. F., e H. A. J. Van Lanen. "A process-based typology of hydrological drought". Hydrology and Earth System Sciences 16, n. 7 (6 luglio 2012): 1915–46. http://dx.doi.org/10.5194/hess-16-1915-2012.
Abstract (sommario):
Abstract. Hydrological drought events have very different causes and effects. Classifying these events into distinct types can be useful for both science and management. We propose a hydrological drought typology that is based on governing drought propagation processes derived from catchment-scale drought analysis. In this typology six hydrological drought types are distinguished, i.e. (i) classical rainfall deficit drought, (ii) rain-to-snow-season drought, (iii) wet-to-dry-season drought, (iv) cold snow season drought, (v) warm snow season drought, and (vi) composite drought. The processes underlying these drought types are the result of the interplay of temperature and precipitation at catchment scale in different seasons. As a test case, about 125 groundwater droughts and 210 discharge droughts in five contrasting headwater catchments in Europe have been classified. The most common drought type in all catchments was the classical rainfall deficit drought (almost 50% of all events), but in the selected catchments these were mostly minor events. If only the five most severe drought events of each catchment are considered, a shift towards more rain-to-snow-season droughts, warm snow season droughts, and composite droughts was found. The occurrence of hydrological drought types is determined by climate and catchment characteristics. The drought typology is transferable to other catchments, including outside Europe, because it is generic and based upon processes that occur around the world. A general framework is proposed to identify drought type occurrence in relation to climate and catchment characteristics.
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Erfurt, Mathilde, Georgios Skiadaresis, Erik Tijdeman, Veit Blauhut, Jürgen Bauhus, Rüdiger Glaser, Julia Schwarz, Willy Tegel e Kerstin Stahl. "A multidisciplinary drought catalogue for southwestern Germany dating back to 1801". Natural Hazards and Earth System Sciences 20, n. 11 (9 novembre 2020): 2979–95. http://dx.doi.org/10.5194/nhess-20-2979-2020.
Abstract (sommario):
Abstract. Droughts are multidimensional hazards that can lead to substantial environmental and societal impacts. To understand causes and impacts, multiple perspectives need to be considered. Many studies have identified past drought events and investigated drought propagation from meteorological droughts via soil moisture to hydrological droughts, and some studies have included the impacts of these different types of drought. However, it is not certain whether the increased frequency and severity of drought events in the past decade is unprecedented in recent history. Therefore, we analyze different droughts and their impacts in a regional context using a multidisciplinary approach. We compile a comprehensive and long-term dataset to investigate possible temporal patterns in drought occurrence and place recent drought events into a historical context. We assembled a dataset of drought indices and recorded impacts over the last 218 years in southwestern Germany. Meteorological and river-flow indices were used to assess the natural drought dynamics. In addition, tree-ring data and recorded impacts were utilized to investigate drought events from an ecological and social perspective. Since 1801, 20 extreme droughts have been identified as common extreme events when applying the different indices. All events were associated with societal impacts. Our multi-dataset approach provides insights into similarities but also the unique aspects of different drought indices.
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Van Loon, A. F., e H. A. J. Van Lanen. "A process-based typology of hydrological drought". Hydrology and Earth System Sciences Discussions 8, n. 6 (22 dicembre 2011): 11413–83. http://dx.doi.org/10.5194/hessd-8-11413-2011.
Abstract (sommario):
Abstract. Hydrological drought events have very different causes and effects. Classifying these events into distinct types can be useful for both science and management. We propose a classification of hydrological drought types that is based on the governing drought propagation processes. In this classification six hydrological drought types are distinguished, i.e. (i) classical rainfall deficit drought, (ii) rain-to-snow-season drought, (iii) wet-to-dry-season drought, (iv) cold snow season drought, (v) warm snow season drought, and (vi) composite drought. The processes underlying these drought types are a result of the interplay of temperature and precipitation at catchment scale in different seasons. As a test case, about 125 groundwater droughts and about 210 discharge droughts in five contrasting headwater catchments in Europe have been classified. The most common drought type in all catchments is the classical rainfall deficit drought (almost 50% of all events), but in the selected catchments these are mostly minor events. If only the five most severe drought events of each catchment are considered, a shift towards more rain-to-snow-season droughts, warm snow season droughts, and composite droughts is found. The occurrence of hydrological drought types is determined by climate and catchment characteristics. The typology is transferable to other catchments, incl. outside Europe, because it is generic and based upon processes that occur around the world. A general framework is proposed to identify drought type occurrence in relation to climate and catchment characteristics.
4
Cunha, Ana Paula M. A., Marcelo Zeri, Karinne Deusdará Leal, Lidiane Costa, Luz Adriana Cuartas, José Antônio Marengo, Javier Tomasella et al. "Extreme Drought Events over Brazil from 2011 to 2019". Atmosphere 10, n. 11 (24 ottobre 2019): 642. http://dx.doi.org/10.3390/atmos10110642.
Abstract (sommario):
Drought-related disasters are among the natural disasters that are able to cause large economic and social losses. In recent years, droughts have affected different regions of Brazil, impacting water, food, and energy security. In this study, we used the Integrated Drought Index (IDI), which combines a meteorological-based drought index and remote sensing-based index, to assess the drought events from 2011 to 2019 over Brazil. During this period, drought events were observed throughout the country, being most severe and widespread between the years 2011 and 2017. In most of the country, the 2014/15 hydrological year stands out due to the higher occurrence of severe and moderate droughts. However, drought intensity and observed impacts were different for each region, which is shown by the different case studies, assessing different types of impacts caused by drought in Brazil. Thus, it is fundamental to evaluate the impacts of droughts in a continental country such as Brazil, where a variety of vegetation, soil, land use, and especially different climate regimes predominate.
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Burn, Donald H., e William J. DeWit. "Spatial characterization of drought events using synthetic hydrology". Canadian Journal of Civil Engineering 23, n. 6 (1 dicembre 1996): 1231–40. http://dx.doi.org/10.1139/l96-932.
Abstract (sommario):
This paper describes an approach to spatial drought analysis based on multi-site streamflow synthesis. The approach developed can be used to assist with the quantification of the return period for the drought of record and can also be used to facilitate the identification of daesign drought events of a specified return period. The approach was applied to the Nelson–Churchill River basin in Manitoba, Canada. For this system, the impacts of droughts on power generation were investigated in addition to a determination of the return period for the drought of record. Key words: droughts, streamflow generation, frequency analysis, hydroelectric power.
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Zhao, Ruxin, Siquan Yang, Hongquan Sun, Lei Zhou, Ming Li, Lisong Xing e Rong Tian. "Extremeness Comparison of Regional Drought Events in Yunnan Province, Southwest China: Based on Different Drought Characteristics and Joint Return Periods". Atmosphere 14, n. 7 (16 luglio 2023): 1153. http://dx.doi.org/10.3390/atmos14071153.
Abstract (sommario):
Droughts frequently occur in Yunnan province, the southwest of China, which leads to crop loss, ecosystem degradation, and difficulties in drinking water for people. In order to assess and compare the extremeness for different drought events, this study quantified it by utilizing the joint return period of drought multi-characteristics. Three characteristics at the regional scale: drought duration, severity, and affected areas were obtained by a simple regional drought process methodology, and their relationship was considered based on three types of Archimedean Copulas. Standard Precipitation Evapotranspiration Index at a six-month time scale was selected as the optimal drought index based on actual drought impact data. Results showed that drought events in Yunnan province were mostly short drought duration, low severity, and high drought-affected areas. By comparing the historical reported droughts’ loss, the return periods of drought events calculated by the combination of duration and severity and drought-affected area are much more suitable to reflect the real drought situations than those calculated by one- or two-dimensional drought characteristics, especially for extreme drought events. On average, the drought in Yunnan province was almost shown a return period of ~10 yr. The frequency of droughts in Yunnan province has gradually increased due to climate change, and droughts with ~100 yr or even larger return periods occurred in 2009–2010 and 2011–2013.
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Fluixá-Sanmartín, Javier, Deng Pan, Luzia Fischer, Boris Orlowsky, Javier García-Hernández, Frédéric Jordan, Christoph Haemmig, Fangwei Zhang e Jijun Xu. "Searching for the optimal drought index and timescale combination to detect drought: a case study from the lower Jinsha River basin, China". Hydrology and Earth System Sciences 22, n. 1 (1 febbraio 2018): 889–910. http://dx.doi.org/10.5194/hess-22-889-2018.
Abstract (sommario):
Abstract. Drought indices based on precipitation are commonly used to identify and characterize droughts. Due to the general complexity of droughts, the comparison of index-identified events with droughts at different levels of the complete system, including soil humidity or river discharges, relies typically on model simulations of the latter, entailing potentially significant uncertainties. The present study explores the potential of using precipitation-based indices to reproduce observed droughts in the lower part of the Jinsha River basin (JRB), proposing an innovative approach for a catchment-wide drought detection and characterization. Two indicators, namely the Overall Drought Extension (ODE) and the Overall Drought Indicator (ODI), have been defined. These indicators aim at identifying and characterizing drought events on the basin scale, using results from four meteorological drought indices (standardized precipitation index, SPI; rainfall anomaly index, RAI; percent of normal precipitation, PN; deciles, DEC) calculated at different locations of the basin and for different timescales. Collected historical information on drought events is used to contrast results obtained with the indicators. This method has been successfully applied to the lower Jinsha River basin in China, a region prone to frequent and severe droughts. Historical drought events that occurred from 1960 to 2014 have been compiled and cataloged from different sources, in a challenging process. The analysis of the indicators shows a good agreement with the recorded historical drought events on the basin scale. It has been found that the timescale that best reproduces observed events across all the indices is the 6-month timescale.
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Tian, Lu, Markus Disse e Jingshui Huang. "Drought cascades across multiple systems in Central Asia identified based on the dynamic space–time motion approach". Hydrology and Earth System Sciences 27, n. 22 (15 novembre 2023): 4115–33. http://dx.doi.org/10.5194/hess-27-4115-2023.
Abstract (sommario):
Abstract. Drought is typically induced by the extreme water deficit stress that cascades through the atmosphere, hydrosphere, and biosphere. Cascading drought events could cause severe damage in multiple systems. However, identifying cascading drought connections considering the dynamic space–time progression remains challenging, which hinders further exploring the emergent patterns of drought cascades. This study proposes a novel framework for tracking drought cascades across multiple systems by utilizing dynamic space–time motion similarities. Our investigation focuses on the four primary drought types in Central Asia from 1980 to 2007, namely precipitation (PCP), evapotranspiration (ET), runoff, and root zone soil moisture (SM), representing the four systems of atmosphere, hydrosphere, biosphere, and soil layer respectively. A total of 503 cascading drought events are identified in this study, including the 261 four-system cascading drought events. Our results show a significant prevalence of the four-system cascading drought pattern in Central Asia with high systematic drought risk, mainly when seasonal PCP droughts with high severity/intensity and sizeable spatial extent are observed. As for the temporal order in the cascading drought events, ET droughts are likely to occur earlier than runoff droughts after PCP droughts, and SM droughts are more likely to occur at last, implying the integrated driven effect of the energy-limited and water-limited phases on the drought progression in Central Asia. Our proposed framework could attain precise internal spatial trajectories within each cascading drought event and enable the capture of space–time cascading connections across diverse drought systems and associated hazards. The identification of cascading drought patterns could provide a systematic understanding of the drought evolution across multiple systems under exacerbated global warming.
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Xiong, Qian, Zhongyi Sun, Wei Cui, Jizhou Lei, Xiuxian Fu e Lan Wu. "A Study on Sensitivities of Tropical Forest GPP Responding to the Characteristics of Drought—A Case Study in Xishuangbanna, China". Water 14, n. 2 (7 gennaio 2022): 157. http://dx.doi.org/10.3390/w14020157.
Abstract (sommario):
Droughts that occur in tropical forests (TF) are expected to significantly impact the gross primary production (GPP) and the capacity of carbon sinks. Therefore, it is crucial to evaluate and analyze the sensitivities of TF-GPP to the characteristics of drought events for understanding global climate change. In this study, the standardized precipitation index (SPI) was used to define the drought intensity. Then, the spatially explicit individual-based dynamic global vegetation model (SEIB-DGVM) was utilized to simulate the dynamic process of GPP corresponding to multi-gradient drought scenarios—rain and dry seasons × 12 level durations × 4 level intensities. The results showed that drought events in the dry season have a significantly greater impact on TF-GPP than drought events in the rainy season, especially short-duration drought events. Furthermore, the impact of drought events in the rainy season is mainly manifested in long-duration droughts. Due to abundant rainfall in the rainy season, only extreme drought events caused a significant reduction in GPP, while the lack of water in the dry season caused significant impacts due to light drought. Effective precipitation and soil moisture stock in the rainy season are the most important support for the tropical forest dry season to resist extreme drought events in the study area. Further water deficit may render the tropical forest ecosystem more sensitive to drought events.
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Xu, Yiran, Fan Lu, Benqing Ruan, Yanyu Dai e Kangming Wang. "Analysis of the spatio-temporal propagation of drought over Eastern China using complex networks". E3S Web of Conferences 346 (2022): 01003. http://dx.doi.org/10.1051/e3sconf/202234601003.
Abstract (sommario):
Understanding of the spatio-temporal propagation of drought is a challenging issue as the hydro-climatic processes are inter-connected. Recent developments in network theory offer new avenues to study the propagation of drought. Three metrics that quantify the strength, dominant orientation and distance of droughts are employed to investigate the spatio-temporal propagation. The results show that (1) the network approach based on the event synchronization is a useful tool to study the propagation of drought; (2) The drought events occurring in the south of the study area are more likely to spread outward, and the drought events occurring in the midwestern regions are more likely to be affected by drought events in other regions; (3) The dominant position of drought transmission in the study area has obvious regional characteristics. The midwestern regions are more susceptible to the influence of drought events in the western regions, while other regions are more likely to spread drought events to the inside world. The findings of this paper could help researchers to initially understand the propagation of spatio-temporal droughts over Eastern China.
Tesi sul tema "Drought events":
1
Cole, Andrew. "The response of grassland carbon cycling to drought events and changes in nutrient availability". Thesis, Lancaster University, 2016. http://eprints.lancs.ac.uk/86756/.
Abstract (sommario):
In grasslands, climate change has the potential to disrupt a range of ecosystem services, including agricultural production, carbon (C) storage and nutrient cycling. In particular, climate change is likely to increase the frequency and severity of extreme climate events, such as drought and the subsequent rewetting event. Yet the effect of drought events will not be consistent across grassland communities, instead likely varying with grassland properties. One such property may be the level of nutrient availability, which brings about changes in plant productivity, plant community composition, and soil microbial composition and function. In this thesis, the effect of reduced precipitation on C cycling in UK species-rich grasslands is investigated in two field experiments, with varying long-term grassland restoration treatments and short-term nutrient addition, and a glasshouse experiment with reduced soil moisture. It was hypothesised that changes in plant and soil microbial communities, brought about by differences in nutrient availability, would modulate above and belowground C cycling responses to drought. This thesis found that the level of nutrient availability was important for modulating how C is cycled in response to drought in plants, soil microbial communities and whole ecosystem CO2 fluxes. For plants, the effect of drought and nutrient availability differed between functional groups, species and due to intraspecific trait variation. For soil microbial communities, the effect of drought on carbon use efficiency was modulated by short-term nutrient addition. Increased nutrient availability and drought therefore interact to determine how C is cycled and stored in plants and soil microbial communities, revealing the importance of agricultural practices in modulating whole community responses to climate change. Overall, this thesis shows the mechanisms by which drought may alter C cycling and its potential feedbacks to climate are complex, but at least in part, depend on the level of nutrient availability.
2
Hausler, Melanie. "Assessment of the hydrological effect of drought and fire events on evapotranspiration at a regional scale". Doctoral thesis, ISA/UL, 2019. http://hdl.handle.net/10400.5/18337.
Abstract (sommario):
Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia / ULUntil today, there is only little knowledge about the behavior of actual evapotranspiration (ETa) before and after wildfires in Portugal, which can be estimated from remote sensing techniques. In this thesis, an existing Simplified Two-Source Energy Balance model (STSEB) was adapted, based on moderate resolution imagery to estimate ETa and its contributing parts of transpiration and evaporation. The study served to test the model and its precision. A bias of about 1 mm d1 for the estimated ETa was observed, where evaporation was regularly overestimated and transpiration underestimated. This error is acceptable for two-layer models based on satellite imagery, but estimates cannot be used for irrigation management. The evolution of the estimated ETa after wildfires (up to four years) was analyzed at eucalypt stands at the Caramulo mountain range in Portugal. By investigating the recovery of ETa after wildfire, the difference between burnt and unburnt stands was mainly related to fire severity and stand characteristics. Two to three years after the fire events, the difference between burnt and unburnt stands became nonsignificant for all severity classes. At the same region, the prediction of soil moisture deficit from drought indices was tested. The drought indices empirically estimate the dryness of an area and are directly related to fire danger. They are based on a simple water balance equation where effective rainfall and ETa are the only input and output, respectively. In this work the empirical equation of (ETa) was substituted by the estimated ETa from STSEB, which enhanced the spatial resolution of the drought indices, being regularly interpolated from point estimates. Spatial patterns of soil moisture deficit were predicted, which indicated a relationship to fire occurrences. To conclude, the ETa estimated by the remote sensing based STSEB model, was used to make observations of the water cycle on a regional scale. In contrast to other post-fire studies, eucalypt stands in Portugal were found to be subject to a smaller hydrological impact after wildfires. This implies a fast recovery and a smaller influence on streamflow and groundwater resources. Furthermore, the drought indices, using the ETa from STSEB, identified areas with higher proneness to drought, by improving the spatial resolution, using satellite imagery compared to traditional interpolation techniques. The results support fire danger rating and might help to improve fire regime and forest management
N/A
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Rodrigues, Allan Soljenitsin Barreto. "Jornalismo e meio ambiente na Amazônia: a cobertura de eventos ambientais extremos pela imprensa escrita de Manaus". Universidade Federal do Amazonas, 2013. http://tede.ufam.edu.br/handle/tede/3140.
Abstract (sommario):
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Previous issue date: 2013-04-30This multidisciplinary research starts from these premises and has as objective the press coverage of the droughts taken place in Amazonas from 2005 to 2010. The question that guided this investigation was: Was the Amazon written Press able to efficiently inform its public about the drought phenomenona and its implications? To answer that question it was necessary to use methodological tools and theoretical structures of various areas of Social Sciences like Communication, Journalism, Sociology, Political Sciences among others. As a general goal, we had the analysis of the scientific and environmental information quality passed through Diario do Amazonas and A Crítica newspapers during the press coverage of both extreme climatic events. The methodology used was the quantitative and qualitative. In the quantitative area, it was used the content analysis since it is used to detect tendencies and criteria analysis models of noticing, framing and scheduling. The method consisted of the collecting and analysis, based on the fixed categories taking into account the journalistic principles and environmental issues approach of journalistic texts that deal with the droughts taken place in Amazonas. In the qualitative area, interviews were used with the intent of broaden out the analytical image beyond the message (news) focusing the communication process in a broader way, including source studies, the messengers (journalists) and receptors (readers). Joining the content analysis results and the information obtained from the interviews, we are able to infer the lack of quality information received by the readers from both main newspapers in Manaus, having as ground the journalistic principles and its scientific and environmental types. The investigation also pointed out the small contribution of the journalistic droughts coverage in Amazonas in 2005 and 2010 to the decision taking cleared up by the citizens of the main Amazon capital over the issues regarding global climatic changes. We identified the fragilities of the coverage and proposed ways to meet the requirements of the informative content regarding the environmental issues and its consequences in the Amazon.
Esta pesquisa tem como objeto a cobertura jornalística das secas ocorridas na Amazônia nos anos de 2005 e 2010. Nosso objetivo geral foi a análise da qualidade das informações científicas e ambientais passadas pelos jornais Diário do Amazonas e A Crítica durante as coberturas jornalísticas destes dois eventos climáticos extremos. A pergunta que presidiu a investigação concentrou-se na indagação se a imprensa escrita do Amazonas conseguiu ou não informar eficientemente seu público sobre os fenômenos das secas e suas implicações para a vida das populações. Para dar conta da resposta, foi necessário lançar mão de ferramentas metodológicas e arcabouços teóricos de várias áreas das Ciências Sociais, como a Comunicação, o Jornalismo, a Sociologia, a Ciência Política e outras. A metodologia assumiu a perspectiva das abordagens qualitativas e quantitativas. No aspecto quantitativo, utilizamos a análise de conteúdo pelo fato de ser uma técnica para detectar tendências e modelos de análise de critérios de noticiabilidade, enquadramentos e agendamentos. Este método compreendeu o recolhimento e análise, com base em categorias estabelecidas levando em conta os princípios do jornalismo e a abordagem da questão ambiental, dos textos jornalísticos que tratam sobre o fenômeno das secas ocorridas no Amazonas. No aspecto qualitativo, fizemos uso de entrevistas com o intuito de ampliar o espectro analítico para além da mensagem (reportagens) focalizando o processo comunicacional de forma mais ampla, incluindo o estudo das fontes, dos emissores (jornalistas) e dos receptores (leitores). Aliando os resultados da análise de conteúdo com as informações obtidas nas entrevistas conseguimos aferir a falta de qualidade da informação recebida pelos leitores dos dois principais jornais impressos de Manaus tendo como base os princípios do jornalismo e de seus gêneros científico e ambiental. A investigação também apontou a pouca contribuição da cobertura jornalística das secas no Amazonas em 2005 e 2010 para tomadas de decisão esclarecidas por parte dos moradores da principal capital da Amazônia sobre as questões relacionadas às mudanças climáticas globais. Identificamos ainda as fragilidades da cobertura e propomos caminhos para qualificar o conteúdo informativo acerca da questão ambiental e seus desdobramentos na Amazônia.
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Erfaneh, Sharifi. "Stochastic Modeling of Hydrological Events for Better Water Management". Kyoto University, 2016. http://hdl.handle.net/2433/217181.
Abstract (sommario):
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第20006号
農博第2190号
新制||農||1045(附属図書館)
学位論文||H28||N5015(農学部図書室)
33102
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 藤原 正幸, 教授 村上 章, 准教授 宇波 耕一
学位規則第4条第1項該当
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Phillips, Ian Douglas. "The occurrence, dynamical structure and prediction of drought events over Devon and Cornwall over a forty year period". Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343455.
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Vieira, Ricardo Jorge Almeida. "Biochemical and physiological changes on three commercial marine fish species to extreme weather events". Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22233.
Abstract (sommario):
Mestrado em Biologia MarinhaThe effect of climate change is an issue of major concern to the scientific community and politicians, with the register, at the past decades, of extreme climate events worldwide. A biomarker based biomonitoring program represents a promising approach, due to its usage to assess the health status of organisms with the biochemical response may be used as early-warning signal of chemical (e.g. pollutants) and environmental stress conditions. However, it is of high importance to develop further approaches, to identify standard key species and organs to diagnose and determine damages caused by severe weather events in studies in situ. This work aims to investigate biomarker responses, in situ, in the liver and at the brain of three marine fish species (Dicentrarchus labrax, Platichthys flesus and Solea solea), from the Mondego estuary (Portugal), during two distinct extreme climatic events (drought (2012) and flood (2014)) in order to determine their baseline levels and to identify the organ to be used as endpoint in ecotoxicological studies. In addition, biochemical analyzes were supplemented with physiological indices of the sampled organisms, diagnosing their physiological state and implications for the antioxidant potential. Severe climatic events had distinct modes of action affecting the physiological condition of the studied species. Biochemical experimental approach shows that the brain has a low antioxidant defense system compared to the liver, increased ROS accumulation rates, making it particularly susceptible to oxidative damage during the dry event. In the flood event, the antioxidant potential of the brain compared to the liver revealed higher difficulty in detoxification of xenobiotic compounds. According to higher oxidative sensitivity of the brain, this organ shows to be a good indicator to assess the influence of climate change in aquatic ecosystems, using the liver as a reference organ, less sensitive to the factors above mentioned, although until now the organ often used in the analysis of oxidative metabolism.
Um assunto que tem requerido especial atenção por parte da comunidade científica e de políticos é o efeito das alterações climáticas, tendo-se registado nas últimas décadas eventos climáticos extremos cada vez mais frequentes mundialmente. A biomonitorização dos sistemas aquáticos baseada em análise de biomarcadores permite avaliar o estado fisiológico dos organismos e utilizar as respostas bioquímicas como sinais de alerta precoce de condições de stress ambientais ou químicos. Porém, é fundamental desenvolver e aprofundar estas metodologias de modo a identificar espécies aquáticas standard e órgãos chave que permitam diagnosticar os impactos provocados por fenómenos climáticos em estudos in situ. O presente trabalho tem como objectivo principal determinar as respostas in situ de biomarcadores analisados no fígado e no cérebro de três espécies de peixes marinhos (Dicentrarchus labrax, Platichthys flesus e Solea solea), recolhidos no estuário do Mondego (Portugal), em dois anos distintos, e sob a influência de eventos climáticos extemos (seca (2012), e inundação (2014)), de modo a determinar os níveis basais e identificar o órgão a ser usado como indicador em estudos ecotoxicológicos. As análises bioquímicas foram complementadas com índices fisiológicos dos organismos capturados, permitindo determinar o estado fisiológico dos organismos e implicações no sistema de defesa antioxidante. Os eventos climáticos extremos tiveram distintos modos de acção tendo-se registado no ano de seca a interrupção na dinâmica dos condutores ambientais, o que afectou a condição fisiológica das espécies estudadas. A análise bioquímica indica que o cérebro tem um sistema de defesa antioxidante baixo em comparação com o fígado, maiores taxas de acumulação de ROS, tornando-o particularmente susceptível ao dano oxidativo no ano de seca. O potencial antioxidante do cérebro comparado com o do fígado no ano onde se registaram inundações revelou maior dificuldade deste órgão na desintoxicação de compostos xenobióticos. De acordo com a maior sensibilidade oxidativa do cérebro, este órgão mostra ser um bom indicador na avaliação dos impactos das alterações climáticas nos ecossistemas aquáticos, utilizando o fígado como órgão de referência, menos sensível aos factores acima mencionados, no entanto, até ao momento, o órgão preferencial na análise do metabolismo oxidativo.
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Skiadaresis, Georgios [Verfasser], Jürgen [Akademischer Betreuer] Bauhus e Kerstin [Akademischer Betreuer] Stahl. "Effects of groundwater extraction and extreme drought events on vitality and growth of pedunculate oak (Quercus robur L.) trees". Freiburg : Universität, 2020. http://d-nb.info/1231711809/34.
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Tran, Hoa Thi. "Integration of Geospatial Technologies in Monitoring Drought Events in a Coastal Area of Vietnam (Case study: Binh Thuan Province)". Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/95471.
Abstract (sommario):
Drought is a climatic event regarding prolonged "drier than normal" conditions. Precipitation deficits, crop-moisture stress, soil-water unbalance, sudden stream flow cut-offs and low carrying capacity of ecosystems are responses to drought. Drought can occur in humid to arid climates, however, drought is more severe in arid and semi-arid areas due to the fact that in those distinctive areas, water resources are extremely limited and restricted. Additionally, local ecologies and ecosystems in arid regions are very fragile. Once a water competition occurs, critical services of ecosystems such as pure water, recreation, and land productivity will be threatened.
This research focuses on prolonged drought events that have been occurring more frequently in a coastal province of South Central Vietnam – named Binh Thuan. The study area is distinctive because its climate is characterized as one of the driest provinces in Vietnam. Annual rainfall in the North and near the coast of the province is less than 800 mm per year. During 6 months of dry season, there is almost no rain, or less than 50 mm. Due to precipitation deficits and high surface temperatures in recent years, meteorological droughts have occurred more frequently, and lasted longer, thereby stressing water resources for vegetation, wildlife, households, and industry. The occurrence of prolonged droughts has constrained economic activities in the coastal areas, especially agriculture and aquaculture. Furthermore, a long duration of dry conditions coupled with unsustainable land management (such as overgrazing), "drought-sensitive" soils in areas with sand and barren lands may introduce and accelerate risks of desertification processes (land productivity deterioration and unable to recover).
This research uses geospatial technologies to monitor drought severity and drought impacts on land use and land cover. Chapter 1 is a brief introduction and literature review of the drought context in Binh Thuan Province to place the research questions and objectives in content. Chapter 2 discusses the occurrence of meteorological droughts in Binh Thuan Province, then proposes climatic indices able to monitor this type of drought. Chapter 3 focuses on explaining and assessing uneven dry conditions that stressed vegetation health in the study area. This chapter investigates spatiotemporal distributions and frequencies of prolonged agricultural droughts using remotely sensed data and anomalies of precipitation distribution. Results indicate that coastal areas in the North of Binh Thuan are subject to severe droughts. Chapter 4 assesses human impacts on land management and practices in the study area during drought periods. Results show that in recent years (2010 to present), local governments and residents have implemented strategies to prevent sand dominance and to adapt to water shortages during dry seasons, such as vegetative cover, crop rotation with drought-tolerant plants and wind breaks. Accuracy was assessed using field data collected in the summer of 2016, in conjunction with Google Earth imagery.
In summary, this dissertation enhances understanding of drought events and impacts in Binh Thuan Province by considering different types of drought - meteorological and agricultural drought, and interactions of drought and human impacts upon land management and land practices during dry periods. Furthermore, findings and results of this research have demonstrated the effectiveness of remotely sensed datasets, and other geospatial technologies, such as geographic information systems, in modeling drought severity and in examining efforts and drought-adaptive practices of local residents. This work is a valuable foundation on which further studies can build to support policy development to protect and reserve soil-land productivity in Binh Thuan and other coastal regions of Vietnam affected by prolonged droughts.Doctor of Philosophy
Drought is a temporal climatic event with "drier than normal" conditions. While drought can occur in any climates, it can be more extreme in arid and semi-arid areas where annual rainfall and water resources are limited. Depending on types of drought, its presences and impacts may differ: (1) meteorological drought relates to a decrease of average rainfall/snowfall may resulting in moisture stress, (2) hydrological drought leads to a reduction of streamflow and groundwater, and (3) agricultural drought influences soil-water-crop balance or vegetation health. Prolonged drought – abnormally long duration of dry conditions, coupled with unsustainable management in water and land practice may cause losses of land productivity, promote soil erosion, and result in sand dominance in coastal areas. These land degradation processes can lead to "a desert-like condition" in impacted areas. This research concerns drought and its impacts in a coastal province in South central Vietnam, Binh Thuan. The study area is distinctive because its climate is characterized as one of the driest provinces in Vietnam. Annual rainfall in the North and near the coast is less than 800 mm per year, and during the 6 months of the dry season, there is almost no rain, or less than 50 mm. Due to precipitation deficits and high surface temperatures in recent years, meteorological droughts have occurred more frequently and lasted longer, stressing water resources for vegetation, wildlife, households, and industry. Additionally, unsustainable land management, such as overgrazing, coupled with movements of sand and barren lands from the coast inland, have accelerated the risks of land degradation. This research applies an integration of geospatial technologies for monitoring drought severity and impacts on land management and illustrates how local people have adapted to droughts.
9
Chattopadhyay, Somsubhra. "IMPACT OF CLIMATE CHANGE ON EXTREME HYDROLOGICAL EVENTS IN THE KENTUCKY RIVER BASIN". UKnowledge, 2017. http://uknowledge.uky.edu/bae_etds/50.
Abstract (sommario):
Anthropogenic activities including urbanization, rapid industrialization, deforestation and burning of fossil fuels are broadly agreed on as primary causes for ongoing climate change. Scientists agree that climate change over the next century will continue to impact water resources with serious implications including storm surge flooding and a sea level rise projected for North America. To date, the majority of climate change studies conducted across the globe have been for large-sized watersheds; more attention is required to assess the impact of climate change on smaller watersheds, which can help to better frame sustainable water management strategies.
In the first of three studies described in this dissertation, trends in annual precipitation and air-temperature across the Commonwealth of Kentucky were evaluated using the non-parametric Mann-Kendall test considering meteorological time series data from 84 weather stations. Results indicated that while annual precipitation and mean annual temperature have been stable for most of Kentucky over the period 1950-2010, there is evidence of increases (averages of 4.1 mm/year increase in annual precipitation and 0.01 °C/year in mean annual temperature) along the borders of the Kentucky. Considered in its totality, available information indicates that climate change will occur – indeed, it is occurring – and while much of the state might not clearly indicate it at present, Kentucky will almost certainly not be exempt from its effects. Spatial analysis of the trend results indicated that eastern part of the state, which is characterized by relatively high elevations, has been experiencing decreasing trends in precipitation.
In the second study, trends and variability of seven extreme precipitation indices (total precipitation on wet days, PRCPTOT; maximum length of dry and wet periods, CDD and CWD, respectively; number of days with precipitation depth ≥20 mm, R20mm; maximum five-day precipitation depth, RX5day; simple daily precipitation intensity, SDII; and standardized precipitation index, SPI were analyzed for the Kentucky River Basin for both baseline period of 1986-2015 and the late-century time frame of 2070-2099. For the baseline period, the majority of the indices demonstrated increasing trends; however, statistically significant trends were found for only ~11% of station-index combinations of the 16 weather stations considered. Projected magnitudes for PRCPTOT, CDD, CWD, RX5day and SPI, indices associated with the macroweather regime, demonstrated general consistency with trends previously identified and indicated modest increases in PRCPTOT and CWD, slight decreases in CDD, mixed results for RX5day, and increased non-drought years in the late century relative to the baseline period. The study’s findings indicate that future conditions might be characterized by more rainy days but fewer large rainfall events; this might lead to a scenario of increased average annual rainfall but, at the same time, increased water scarcity during times of maximum demand.
In the third and final study, the potential impact of climate change on hydrologic processes and droughts over the Kentucky River basin was studied using the watershed model Soil and Water Assessment Tool (SWAT). The SWAT model was successfully calibrated and validated and then forced with forecasted precipitation and temperature outputs from a suite of CMIP5 global climate model (GCMs) corresponding to two different representative concentration pathways (RCP 4.5 and 8.5) for two time periods: 2036-2065 and 2070-2099, referred to as mid-century and late-century, respectively. Climate projections indicate that there will be modest increases in average annual precipitation and temperature in the future compared to the baseline (1976-2005) period. Monthly variations of water yield and surface runoff demonstrated an increasing trend in spring and autumn, while winter months are projected as having decreasing trends. In general, maximum drought length is expected to increase, while drought intensity might decrease under future climatic conditions. Hydrological droughts (reflective of water availability), however, are predicted to be less intense but more persistent than meteorological droughts (which are more reflective of only meteorological variables). Results of this study could be helpful for preparing any climate change adaptation plan to ensure sustainable water resources in the Kentucky River Basin.
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Kulman, Denilson. "ANALYSIS OF LOCATION AND REFORM OF SETTLEMENTS OF VULNERABILITY FOR AGRICULTURAL DROUGHT EVENTS IN A RIO GRANDE DO SUL - 1981-2011". Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/9436.
Abstract (sommario):
Studies and surveys on climate phenomena serve to plan the geographical space. In
this sense, research has mainly focused on spatialization of the drought in Rio
Grande do Sul from 1981 to 2011 and the location of land reform settlements (PA).
The social issue was viewed from the location of land reform settlements and their
susceptibility to drought. The steps to performing the research consist of literature
review, data surveys in primary and secondary sources, such as INCRA and INPE.
For the treatment of information and preparation of final maps, the SPRING and the
QGIS software were used, along with Ordinary Kriging geostatistical technique. A
fieldwork was also carried out in selected settlements from the location in areas of
high drought occurrence in order to verify the susceptibility of the settlers. The results
are divided into two parts: use of GIS and geostatistical technique for obtaining the
spatial maps of drought occurrence per decade and synthesis map of occurrence for
the whole period of analysis and the PA location map per drought occurrence class.
The second part is the analysis and discussion of the results obtained in maps and
tables with information about the settlements, in order to support the territorial
planning.Estudos e levantamentos sobre os fenômenos climáticos servem para planejar o espaço geográfico. Nesse sentido, a pesquisa tem como objetivo central a espacialização da estiagem no Rio Grande do Sul no período de 1981 a 2011 e a localização dos assentamentos da reforma agrária. Abordou-se a questão social a partir da localização dos assentamentos da reforma agrária e sua vulnerabilidade a estiagem. As etapas de realização da pesquisa consistem em revisão bibliográfica, levantamentos de dados em fontes primárias e secundárias, como INCRA e INPE. Para o tratamento das informações e elaboração dos mapas finais utilizou-se os softwares SPRING, QGIS, e técnica geoestatística da Krigagem Ordinária. Também realizou-se trabalho de campo em assentamentos selecionados a partir da localização em área de alta ocorrência de estiagem com a finalidade de verificar a suscetibilidade dos assentados. Os resultados dividem-se em duas partes: utilização de SIG e técnica geoestatística para a obtenção dos mapas de espacialização de ocorrência da estiagem por década e mapa síntese da ocorrência em todo o período de análise e o mapa de localização dos PAs por classe de ocorrência da estiagem. A segunda parte consiste na análise e discussão dos resultados obtidos nos mapas e tabelas com informações sobre os assentamentos, com a finalidade de subsidiar o planejamento territorial.
Libri sul tema "Drought events":
1
Phillips, Ian Douglas. The occurence, dynamical structure and prediction of drought events over Devon and Cornwall over a forty year period. Birmingham: University of Birmingham, 2000.
2
Mastrandrea, Michael D. Current and future impacts of extreme events in California: Final paper : a paper from California Climate Change Center. Sacramento, Calif.]: California Energy Commission, 2009.
3
Ndichu, Roger W. The most devastating famines in East Africa in the last 1700 years: An account of the worst famine, drought, and flood events, and the social-economic and political impacts experienced in the region (250-1900 AD). Nairobi: Sanctified Printers, 2009.
4
Ndichu, Roger W. The most devastating famines in East Africa in the last 1700 years: An account of the worst famine, drought, and flood events, and the social-economic and political impacts experienced in the region (250-1900 AD). Nairobi: Sanctified Printers, 2009.
5
Ndichu, Roger W. The most devastating famines in East Africa in the last 1700 years: An account of the worst famine, drought, and flood events, and the social-economic and political impacts experienced in the region (250-1900 AD). Nairobi: Sanctified Printers, 2009.
6
W, Paulson R., e Geological Survey (U.S.), a cura di. National water summary 1988-89: Hydrologic events and floods and droughts. [Washington, D.C.]: U.S. G.P.O., 1991.
7
Watkins, Clare Vaye. Gold fame citrus. London: Quercus, 2016.
8
Boken, Vijendra K., Arthur P. Cracknell e Ronald L. Heathcote. Monitoring and Predicting Agricultural Drought. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780195162349.001.0001.
Abstract (sommario):
Agricultural droughts affect whole societies, leading to higher food costs, threatened economies, and even famine. In order to mitigate such effects, researchers must first be able to monitor them, and then predict them; however no book currently focuses on accurate monitoring or prediction of these devastating kinds of droughts. To fill this void, the editors of Monitoring and Predicting Agricultural Drought have assembled a team of expert contributors from all continents to make a global study, describing biometeorological models and monitoring methods for agricultural droughts. These models and methods note the relationships between precipitation, soil moisture, and crop yields, using data gathered from conventional and remote sensing techniques. The coverage of the book includes probabilistic models and techniques used in America, Europe and the former USSR, Africa, Asia, and Australia, and it concludes with coverage of climate change and resultant shifts in agricultural productivity, drought early warning systems, and famine mitigation. This will be an essential collection for those who must advise governments or international organizations on the current scope, likelihood, and impact of agricultural droughts. Sponsored by the World Meterological Organization
9
Courtenay Botterill, Linda, e Melanie Fisher, a cura di. Beyond Drought. CSIRO Publishing, 2003. http://dx.doi.org/10.1071/9780643090972.
Abstract (sommario):
The unpredictability of Australia’s climate poses real challenges for practices that were developed based on the relative predictability of a European climate. More recently, policy has been moving towards accepting drought as a reality, rejecting the notion that it is a natural disaster in favour of an approach based on risk management.
However, the level of public debate during a drought event suggests that this policy approach has not been widely understood or accepted. Media reporting of drought rapidly adopts disaster-related language and the organisation of relief appeals reinforces the impression that drought is an aberration rather than a normal part of Australia’s climate patterns.
Beyond Drought provides a multi-disciplinary discussion aimed at increasing the level of understanding of drought’s many facets and its impact on the environment, communities and the economy. It introduces a range of perspectives in order to emphasise the complexity of drought policy. The book cuts through the often emotional debate that occurs during a drought event, aiming to stimulate reasoned discussion about the best way that Australian farmers and the broader community can live with the vagaries of an uncertain climate.
10
Kennett, Douglas J., e David A. Hodell. AD 750–1100 Climate Change and Critical Transitions in Classic Maya Sociopolitical Networks. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780199329199.003.0007.
Abstract (sommario):
Multiple palaeoclimatic reconstructions point to a succession of major droughts in the Maya Lowlands between AD 750 and 1100 superimposed on a regional drying trend that itself was marked by considerable spatial and temporal variability. The longest and most severe regional droughts occurred between AD 800 and 900 and again between AD 1000 and 1100. Well-dated historical records carved on stone monuments from forty Classic Period civic-ceremonial centers reflect a dynamic sociopolitical landscape between AD 250 and 800 marked by a complex of antagonistic, diplomatic, lineage-based, and subordinate networks. Warfare between Maya polities increased between AD 600 and 800 within the context of population expansion and long-term environmental degradation exacerbated by increasing drought. Nevertheless, in spite of the clear effects of drought on network collapse during the Classic Period, one lingering question is why polities in the northern lowlands persisted and even flourished between AD 800 and 1000 (Puuc Maya and Chichén Itzá) before they too fragmented during an extended and severe regional drought between AD 1000 and 1100. Here we review available regional climate records during this critical transition and consider the different sociopolitical trajectories in the South/Central versus Northern Maya lowlands.
Capitoli di libri sul tema "Drought events":
1
Ndehedehe, Christopher. "Drought Events". In Satellite Remote Sensing of Terrestrial Hydrology, 249–80. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99577-5_11.
2
Bradford, R. B. "Drought Events in Europe". In Drought and Drought Mitigation in Europe, 7–20. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-015-9472-1_2.
3
Nagarajan, R. "Resources, Drought Events and Management Profile of Countries". In Drought Assessment, 364–423. Dordrecht: Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-90-481-2500-5_9.
4
Ballester, Alba, e Abel La Calle. "Drought Governance in Catalonia". In Facing Hydrometeorological Extreme Events, 283–300. Chichester, UK: John Wiley & Sons, Ltd, 2019. http://dx.doi.org/10.1002/9781119383567.ch19.
5
La Jeunesse, Isabelle. "Awareness of Drought Impacts in Europe". In Facing Hydrometeorological Extreme Events, 189–202. Chichester, UK: John Wiley & Sons, Ltd, 2019. http://dx.doi.org/10.1002/9781119383567.ch13.
6
Tröltzsch, Jenny. "Multilevel Governance for Drought Management in Flanders". In Facing Hydrometeorological Extreme Events, 219–32. Chichester, UK: John Wiley & Sons, Ltd, 2019. http://dx.doi.org/10.1002/9781119383567.ch15.
7
Vidaurre, Rodrigo. "Drought Governance in the Eifel-Rur Region". In Facing Hydrometeorological Extreme Events, 233–44. Chichester, UK: John Wiley & Sons, Ltd, 2019. http://dx.doi.org/10.1002/9781119383567.ch16.
8
La Jeunesse, Isabelle, Hans Bressers e Alison Browne. "What Could Change Drought Governance in Europe?" In Facing Hydrometeorological Extreme Events, 301–11. Chichester, UK: John Wiley & Sons, Ltd, 2019. http://dx.doi.org/10.1002/9781119383567.ch20.
9
Özerol, Gül. "National and Local Actors of Drought Governance in Europe". In Facing Hydrometeorological Extreme Events, 171–88. Chichester, UK: John Wiley & Sons, Ltd, 2019. http://dx.doi.org/10.1002/9781119383567.ch12.
10
Bressers, Hans, Nanny Bressers e Stefan Kuks. "Strategies and Instruments to Face Drought and Water Scarcity". In Facing Hydrometeorological Extreme Events, 203–18. Chichester, UK: John Wiley & Sons, Ltd, 2019. http://dx.doi.org/10.1002/9781119383567.ch14.
Atti di convegni sul tema "Drought events":
1
Vizina, Adam, Petr Pavlík, Irina Georgievová, Martin Hanel, Martina Peláková e Eva Melišová. "Warning information and local threshold limits in the HAMR system". In První konference PERUN. Český hydrometeorologický ústav, 2023. http://dx.doi.org/10.59984/978-80-7653-063-8.29.
Abstract (sommario):
Droughts and floods are extreme hydrological events with increasing impacts due to climate change. The PERUN project focuses on drought assessment in the Czech Republic and the innovation of the warning system by ČHMÚ. The Water Act amendment introduces the obligation to inform about drought and forecasting services. Tools are being developed for predicting the state of water resources and creating plans to address drought and water scarcity. The competent body is the Drought Commission at the regional or national level. Warning information is available on the HAMR portal along with the local threshold limits (MSL) of water sources.
2
Nurlatifah, Amalia, Indah Susanti, Edy Maryadi, Sinta Berliana Sipayung, Bambang Siswanto, Hidayatul Latifah, Martono e Mahmud. "Analysis of drought events with TRMM 3B43 satellite". In PROCEEDINGS OF THE 3RD INTERNATIONAL SEMINAR ON METALLURGY AND MATERIALS (ISMM2019): Exploring New Innovation in Metallurgy and Materials. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0002335.
3
Chilikova-Lubomirova, Mila. "EXAMINATION OF URBAN AREAS DROUGHT VULNERABILITY. A TETEVEN TOWN CASE STUDY". In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/5.1/s20.022.
Abstract (sommario):
Climate and weather play significant role in the urban areas function. They impact on the social and economy life, on the environment and infrastructure, on the biodiversity. That`s why the occurrence of extreme or untypical events is a challenge. Droughts are part of these processes. They are prolonged events that can lead to serious harmful impacts. For this purpose of importance is the becoming of reliable knowledge about such behaviour that can serve as a base for the selection of appropriate prevention and mitigation measures. This is possible by the implementation of recent scientific studies in the area that refer best to local specifics. In help of professionals and decision makers in the area this paper focuses on the droughts phenomena in urban areas. It observes the problem as a part of the climateenvironmental nexus. In this context the droughts vulnerability is examined in an integrated way, considering the main aspects and scientific approaches for droughts diagnostics. To illustrate the process in the material are summarized the results of a droughts study for one Bulgarian town � Teteven, situated in the northern slopes of the central Balkan in the Beli Vit river valley. For this reason it is implemented an integrated set of drought indicators that can ensure in parallel the detecting of meteorological and hydrological droughts and to serve for droughts vulnerability evaluation.
4
Evgeniev, Radoslav, Krastina Malcheva, Tania Marinova, Hristo Chervenkov e Lilia Bocheva. "ASSESSMENT OF DROUGHT IN BULGARIA IN RECENT YEARS THROUGH THE STANDARDIZED PRECIPITATION INDEX". In 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023/4.1/s19.31.
Abstract (sommario):
Drought is a complex weather and climate-related phenomenon with significant ecological and socioeconomic consequences. In light of the increasing severity and frequency of droughts in Europe in recent years, this study focuses on assessing the spatiotemporal evolution of drought in Bulgaria during the period 2014-2022. To achieve this, the Standardized Precipitation Index (SPI) is calculated at different time scales (1, 3, and 6 months) for both the country's territory and individual municipalities using software recommended by the World Meteorological Organization. The spatiotemporal analysis is performed in the QGIS environment, utilizing the Ordinary Kriging method for spatial interpolation and the Zonal Statistics tool to calculate selected statistical features at the municipality level. Additionally, area-averaged values are extracted from all raster layers, forming time series spanning the period 2014-2022, which are used for further statistical analysis. The study reveals several drought events, with the most significant occurrence in 2019-2020, affecting 60-80% of the country's territory during certain months. However, the considered period is characterized by normal and wet conditions. The results also show that several municipalities in the western and southeastern regions of the country are particularly vulnerable to severe and extreme droughts. Overall, the study emphasizes the importance of integrating different spatial and time scales in drought monitoring and analysis.
5
Zin, Wan Zawiah Wan, Siti Aishah Nahrawi, Abdul Aziz Jemain e Marina Zahari. "A preliminary study on drought events in Peninsular Malaysia". In PROCEEDINGS OF THE 3RD INTERNATIONAL CONFERENCE ON MATHEMATICAL SCIENCES. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4882639.
6
Chipkar, Sarvada. "Characterizing fungal inhibitors from drought-stressed switchgrass". In The 3rd Global Virtual Conference of the Youth Environmental Alliance in Higher Education. Michigan Technological University, 2021. http://dx.doi.org/10.37099/mtu.dc.yeah-conference/april2021/all-events/42.
7
Toro Ortiz, Yenny Marcela, Sonia Raquel Gámiz-Fortis, Yolanda Castro-Díez, Reiner Palomino-Lemus, María Jesús Esteban-Parra e Samir Córdoba-Machado. "High-resolution decadal predictions analysis of drought events in Colombia". In Proceedings of the 39th IAHR World Congress From Snow to Sea. Spain: International Association for Hydro-Environment Engineering and Research (IAHR), 2022. http://dx.doi.org/10.3850/iahr-39wc2521711920221413.
8
Wei Huang, Zhenli Ma, Chenming Li, Jianying Wang, Xiaodong Wei e Lei Qiu. "Computational experiment system architecture of extreme flood and drought disaster events". In 2011 Second International Conference on Mechanic Automation and Control Engineering (MACE). IEEE, 2011. http://dx.doi.org/10.1109/mace.2011.5987623.
9
Sravanthi, Kollukuduru, e K. S. Rajan. "Mining Spatial Co-occurrence of Drought Events from Climate Data of India". In 2010 IEEE International Conference on Data Mining Workshops (ICDMW). IEEE, 2010. http://dx.doi.org/10.1109/icdmw.2010.142.
10
Cancelliere, Antonino, e Brunella Bonaccorso. "A Non-Stationary Analytical Framework for the Probabilistic Characterization of Drought Events". In World Environmental and Water Resources Congress 2016. Reston, VA: American Society of Civil Engineers, 2016. http://dx.doi.org/10.1061/9780784479858.036.
Rapporti di organizzazioni sul tema "Drought events":
1
Somani, Abhishek, Emily Barrett, Zhi Zhou, Gavin Chan, Luke Middleton, Guillaume Tarel, Allison Campbell et al. An Assessment of Resource Drought Events as Indicators for Long-Duration Energy Storage Needs. Office of Scientific and Technical Information (OSTI), maggio 2024. http://dx.doi.org/10.2172/2349123.
2
Bastos, Paulo, e Sebastián J. Miller. Politics Under the Weather: Droughts, Parties and Electoral Outcomes. Inter-American Development Bank, ottobre 2013. http://dx.doi.org/10.18235/0011513.
Abstract (sommario):
The increased occurrence of extreme weather conditions leading to drought is a key development challenge. This paper studies how these extreme events interact with the political process at the local level using rich administrative data for drought declarations and mayoral elections in Brazil. While accounting for current and historical rainfall patterns, the paper finds that that: i) municipalities led by a mayor affiliated with the President¿s party are more likely to receive formal drought declarations prior to the municipal election; and ii) receiving a drought declaration reinforces the electoral advantage of incumbent mayors running for reelection. These results are robust to the inclusion of a rich set of controls for municipal attributes.
3
Yalovsky, Shaul, e Julian Schroeder. The function of protein farnesylation in early events of ABA signal transduction in stomatal guard cells of Arabidopsis. United States Department of Agriculture, gennaio 2002. http://dx.doi.org/10.32747/2002.7695873.bard.
Abstract (sommario):
Loss of function mutations in the farnesyltransferase β subunit gene ERA1 (enhanced response to abscisic acid), cause abscisic acid hypersensitivity in seedlings and in guard cells. This results in slowed water loss of plants in response to drought. Farnesyltransferase (PFT) catalyses the attachment of the 15-carbon isoprenoid farnesyl to conserved cysteine residues located in a conserved C-terminal domain designated CaaX box. PFT is a heterodimeric protein comprised of an a and b sununits. The a subunit is shared between PFT and geranylgeranyltransferase-I (PGGTI) which catalyses the attachemt of the 20-carbon isoprenoid geranylgeranyl to CaaX box proteins in which the last amino acid is almost always leucine and in addition have a polybasic domain proximal to the CaaL box. Preliminary data presented in the proposal showed that increased cytoplasmic Ca2+ concentration in stomal guard cells in response to non-inductive ABA treatements. The goals set in the proposal were to characterize better how PFT (ERA1) affects ABA induced Ca2+ concentrations in guard cells and to identify putative CaaX box proteins which function as negative regulators of ABA signaling and which function is compromised in era1 mutant plants. To achieve these goals we proposed to use camelion Ca2+ sensor protein, high throughput genomic to identify the guard cell transcriptome and test prenylation of candidate proteins. We also proposed to focus our efforts of RAC small GTPases which are prenylated proteins which function in signaling. Our results show that farnesyltransferaseprenylates protein/s that act between the points of ABA perception and the activation of plasma membrane calcium influx channels. A RAC protein designated AtRAC8/AtRop10 also acts in negative regulation of ABA signaling. However, we discovered that this protein is palmitoylated and not prenylated although it contains a C-terminal CXXX motif. We further discovered a unique C-terminal sequence motif required for membrane targeting of palmitoylatedRACs and showed that their function is prenylation independent. A GC/MS based method for expression in plants, purification and analysis of prenyl group was developed. This method would allow highly reliable identification of prenylated protein. Mutants in the shared α subunit of PFT and PGGT-I was identified and characterized and was shown to be ABA hypersensitive but less than era1. This suggested that PFT and PGGT-I have opposing functions in ABA signaling. Our results enhanced the understanding of the role of protein prenylation in ABA signaling and drought resistance in plants with the implications of developing drought resistant plants. The results of our studies were published 4 papers which acknowledge support from BARD.
4
Arasu, Sibi, e Kaavya Pradeep Kumar. Ways of Telling: A Handbook for Reporting on Climate Change in South India. Indian Institute for Human Settlements, 2021. http://dx.doi.org/10.24943/wthrccsi02.2021.
Abstract (sommario):
Stories around climate change are not easy to tell. They are complex, technical, and develop slowly. In newsrooms where speed is king, accurate and comprehensive reporting on environmental crises often takes a hit. Scientific rigour and accuracy, sensitive representations and consistent reportage on more slow-onset events such as drought and sea-level rise are critical to build public awareness and set the agenda for more ambitious climate policies that cater to the needs of the most vulnerable.
5
Paredes, Juan Roberto, María Clara Ramos, Marina Robles e Emma Näslund-Hadley. Managing Risk in the School. Inter-American Development Bank, aprile 2015. http://dx.doi.org/10.18235/0006246.
Abstract (sommario):
Climate change poses new hazards to schools and heightens preexisting ones. Every day we hear news of some community in the world being adversely affected by natural phenomena such as excess water (floods, landslides), extreme winds, or drought. Such events may leave communities without access to a reliable supply of drinking water, create conditions conducive to the spread of fires, force school closures, and affect the economy. Schools mirror their communities. Just as they face the same risks, they can implement some of the same strategies to counteract the factors that generate those risks lowering them and mitigating the possibility of disaster.
6
Pradeep Kumar, Kaavya. Reporting in a Warming World: A Media Review. Indian Institute for Human Settlements, 2021. http://dx.doi.org/10.24943/rwwmr08.2021.
Abstract (sommario):
The media plays a critical role in terms of shaping public perceptions, but they have a task on their hands in terms of effectively communicating a subject as vast and complex as climate change. India is among the countries most affected and yet reporting on the subject has been episodic, with peaks around the time of climate summits and in the immediate aftermath of disasters such as cyclones, heatwaves and extreme rainfall events. Through a media review, undertaken as part of the Earth Journalism Network Asia-Pacific Media Grant, we sought to understand patterns of representation in news coverage about urban drought and extreme weather events – predicted to occur more frequently and intensely in a warming world. This report details the methodology we followed, our findings and analyses them in the context of other work done as part of the evolving field of climate change communication.
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Lykins, Amy, Joey Tognela, Kylie Robinson, Rosie Ryan e Phillip Tully. The mental health effects of eco-anxiety – a systematic review of quantitative research. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, gennaio 2023. http://dx.doi.org/10.37766/inplasy2023.1.0025.
Abstract (sommario):
Review question / Objective: The aim of the review is to synthesise findings from quantitative studies that investigate ecological grief, eco-anxiety, and climate-anxiety in relation to self-reported mental health. Population of interest: The general adult population aged 18 years. Exposure (risk factor): The exposure is defined as the presence of any ecological grief, eco-anxiety, and/or climate-anxiety that is quantified either before, concurrently, or after a mental health symptom (e.g. depression, and/or anxiety - see Outcomes). As ecological grief, eco-anxiety, and climate-anxiety are relatively new concepts that lack a standard definition, we will include validated and emerging unvalidated self-report measures of these constructs, as well as closely related constructs; solastalgia, eco- and climate-grief, eco- and climate-guilt, eco- and climate-distress, eco- and climate-despair, eco- and climate-worry. Ineligible exposures are detrimental environmental events (e.g. flood, bushfire, drought) or climatic conditions (e.g. ambient temperatures) or distress related to psychosocial impacts of environmental events (e.g. loss of income or housing due to landslide). Comparator: The general adult population aged 18+ without ecological grief, eco-anxiety, and/or climate-anxiety or related constructs as defined above in Exposure. Outcome: The primary outcomes are mental health symptoms quantified by validated self-report measures of depression, anxiety, stress.
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Avis, William. Refugee and Mixed Migration Displacement from Afghanistan. Institute of Development Studies (IDS), agosto 2021. http://dx.doi.org/10.19088/k4d.2022.002.
Abstract (sommario):
This rapid literature review summarises evidence and key lessons that exist regarding previous refugee and mixed migration displacement from Afghanistan to surrounding countries. The review identified a diverse literature that explored past refugee and mixed migration, with a range of quantitative and qualitative studies identified. A complex and fluid picture is presented with waves of mixed migration (both outflow and inflow) associated with key events including the: Soviet–Afghan War (1979–1989); Afghan Civil War (1992–96); Taliban Rule (1996–2001); War in Afghanistan (2001–2021). A contextual picture emerges of Afghans having a long history of using mobility as a survival strategy or as social, economic and political insurance for improving livelihoods or to escape conflict and natural disasters. Whilst violence has been a principal driver of population movements among Afghans, it is not the only cause. Migration has also been associated with natural disasters (primarily drought) which is considered a particular issue across much of the country – this is associated primarily with internal displacement. Further to this, COVID-19 is impacting upon and prompting migration to and from Afghanistan. Data on refugee and mixed migration movement is diverse and at times contradictory given the fluidity and the blurring of boundaries between types of movements. Various estimates exist for numbers of Afghanistan refugees globally. It is also important to note that migratory flows are often fluid involving settlement in neighbouring countries, return to Afghanistan. In many countries, Afghani migrants and refugees face uncertain political situations and have, in recent years, been ‘coerced’ into returning to Afghanistan with much discussion of a ‘return bias’ being evident in official policies. The literature identified in this report (a mix of academic, humanitarian agency and NGO) is predominantly focused on Pakistan and Iran with a less established evidence base on the scale of Afghan refugee and migrant communities in other countries in the region. . Whilst conflict has been a primary driver of displacement, it has intersected with drought conditions and poor adherence to COVID-19 mitigation protocols. Past efforts to address displacement internationally have affirmed return as the primary objective in relation to durable solutions; practically, efforts promoted improved programming interventions towards creating conditions for sustainable return and achieving improved reintegration prospects for those already returned to Afghanistan.
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Lawrence, David, Mike Tercek, Amber Runyon e Jeneva Wright. Historical and projected climate change for Grand Canyon National Park and surrounding areas. National Park Service, 2024. http://dx.doi.org/10.36967/2301726.
Abstract (sommario):
Globally, anthropogenic climate change is one of the greatest threats to resources in protected areas. This report examines historical and projected climate change across the Greater Grand Canyon Landscape (GGCL), including Grand Canyon National Park. Grand Canyon National Park warmed significantly from 1895-2020 (annual mean increase of 1.89? F/century), with temperatures increasing at a faster rate from 1970-2020 (6.31? F/century). Warming occurred at all elevations and seasons across the GGCL, but rates differed spatially. Average annual total precipitation within Grand Canyon National Park did not change significantly over either period examined (1895-2020; 1970-2020). A variety of changes in the region of Grand Canyon National Park have been detected and attributed, at least in part, to anthropogenic climate change, including reduced soil moisture (and associated drought), reduced Colorado River flow, doubling of the area burned by wildfire across the western United States, reduced regeneration of low-elevation ponderosa pine and Douglas-fir as well as pinyon pine and juniper populations, northward shifts in many bird species distributions and declines of bird species occupancy in the Mojave Desert, and reduced bumble bee species richness and abundance (key pollinators). To help managers understand and plan around a range of plausible future climates, we present two plausible but contrasting climate futures for the Greater Grand Canyon Landscape, characterized at mid-century (2040-2069) and late-century (2070-2099). Examining multiple plausible futures avoids over-optimizing management strategies for a single projected future that may not occur. Overarching patterns that emerged from both climate futures include additional warming (average, as well as extreme temperatures), seasonal increases in extreme precipitation events, fewer freezing days and days with snow, and higher moisture deficit (a correlate with landscape dryness, conditions conducive to fire, and vegetation stress). The selected climate futures differed in terms of 1) the degree of warming, 2) whether winter precipitation increases or decreases, 3) whether annual precipitation increases or stays similar, 4) whether drought conditions increase or decrease, and 5) whether runoff increases or decreases. Runoff is projected to occur earlier under both climate futures and is projected to exhibit a more episodic pattern. Based on a literature review, projected changes to the physical, ecological, and cultural resource domains of the region resulting from anthropogenic climate change include: ? Increasing drought risk and aridification ? Reduced Colorado River flow ? Reduced groundwater infiltration ? Decreasing runoff (from snow or rain) in the spring, summer, and fall, and increasing runoff in the winter ? Increasing occurrence of large fires ? Increasing invasive grasses in the Mojave Desert ecosystems west of the park, providing more fuel for wildfire ? Exacerbated post-fire erosion and sediment in Grand Canyon watersheds ? Increased episodes of drought-induced tree mortality ? Upslope shifts of the elevational zones of pinyon-juniper woodland, ponderosa pine forest, and spruce-fir forest, as well as increases in non-forest areas and aboveground biomass declines ? Reduced abundance of riparian vegetation that tolerates water inundation ? Increasing invasive plant distribution and abundance, favoring their establishment and productivity ? Colonization of the GGCL by some bird species and extirpation of others ? Increasing non-native fish populations relative to native fishes ? Declining butterfly populations ? Increasing temperatures will increase visitation, especially during winter and shoulder seasons ? Exacerbation of existing threats to archeological resources, cultural landscapes, and historic structures, as well as emergent vulnerabilities related to climate change One goal of this work is to support the Resource Stewardship Strategy (RSS) process that Grand Canyon National Park plans to undertake. We anticipate that connecting the climate changes described here to the climate sensitivities of resources within the park will play a critical role in setting goals and strategies during development of the RSS, as well as proactively adapting to anticipated changes.
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Kirchhoff, Helmut, e Ziv Reich. Protection of the photosynthetic apparatus during desiccation in resurrection plants. United States Department of Agriculture, febbraio 2014. http://dx.doi.org/10.32747/2014.7699861.bard.
Abstract (sommario):
In this project, we studied the photosynthetic apparatus during dehydration and rehydration of the homoiochlorophyllous resurrection plant Craterostigmapumilum (retains most of the photosynthetic components during desiccation). Resurrection plants have the remarkable capability to withstand desiccation, being able to revive after prolonged severe water deficit in a few days upon rehydration. Homoiochlorophyllous resurrection plants are very efficient in protecting the photosynthetic machinery against damage by reactive oxygen production under drought. The main purpose of this BARD project was to unravel these largely unknown protection strategies for C. pumilum. In detail, the specific objectives were: (1) To determine the distribution and local organization of photosynthetic protein complexes and formation of inverted hexagonal phases within the thylakoid membranes at different dehydration/rehydration states. (2) To determine the 3D structure and characterize the geometry, topology, and mechanics of the thylakoid network at the different states. (3) Generation of molecular models for thylakoids at the different states and study the implications for diffusion within the thylakoid lumen. (4) Characterization of inter-system electron transport, quantum efficiencies, photosystem antenna sizes and distribution, NPQ, and photoinhibition at different hydration states. (5) Measuring the partition of photosynthetic reducing equivalents between the Calvin cycle, photorespiration, and the water-water cycle. At the beginning of the project, we decided to use C. pumilum instead of C. wilmsii because the former species was available from our collaborator Dr. Farrant. In addition to the original two dehydration states (40 relative water content=RWC and 5% RWC), we characterized a third state (15-20%) because some interesting changes occurs at this RWC. Furthermore, it was not possible to detect D1 protein levels by Western blot analysis because antibodies against other higher plants failed to detect D1 in C. pumilum. We developed growth conditions that allow reproducible generation of different dehydration and rehydration states for C. pumilum. Furthermore, advanced spectroscopy and microscopy for C. pumilum were established to obtain a detailed picture of structural and functional changes of the photosynthetic apparatus in different hydrated states. Main findings of our study are: 1. Anthocyan accumulation during desiccation alleviates the light pressure within the leaves (Fig. 1). 2. During desiccation, stomatal closure leads to drastic reductions in CO2 fixation and photorespiration. We could not identify alternative electron sinks as a solution to reduce ROS production. 3. On the supramolecular level, semicrystalline protein arrays were identified in thylakoid membranes in the desiccated state (see Fig. 3). On the electron transport level, a specific series of shut downs occur (summarized in Fig. 2). The main events include: Early shutdown of the ATPase activity, cessation of electron transport between cyt. bf complex and PSI (can reduce ROS formation at PSI); at higher dehydration levels uncoupling of LHCII from PSII and cessation of electron flow from PSII accompanied by crystal formation. The later could severe as a swift PSII reservoir during rehydration. The specific order of events in the course of dehydration and rehydration discovered in this project is indicative for regulated structural transitions specifically realized in resurrection plants. This detailed knowledge can serve as an interesting starting point for rationale genetic engineering of drought-tolerant crops.