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Letteratura scientifica selezionata sul tema "Climatic constraints"

Autore: Grafiati

Pubblicato: 25 gennaio 2025

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Articoli di riviste sul tema "Climatic constraints"

Lazaridi, Efstathia, e Penelope J. Bebeli. "Cowpea Constraints and Breeding in Europe". Plants 12, n. 6 (16 marzo 2023): 1339. http://dx.doi.org/10.3390/plants12061339.

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Cowpea (Vigna unguiculata (L.) Walp.) is a legume with a constant rate of cultivation in Southern European countries. Consumer demand for cowpea worldwide is rising due to its nutritional content, while Europe is constantly attempting to reduce the deficit in the production of pulses and invest in new, healthy food market products. Although the climatic conditions that prevail in Europe are not so harsh in terms of heat and drought as in the tropical climates where cowpea is mainly cultivated, cowpea confronts with a plethora of abiotic and biotic stresses and yield-limiting factors in Southern European countries. In this paper, we summarize the main constraints for cowpea cultivation in Europe and the breeding methods that have been or can be used. A special mention is made of the availability plant genetic resources (PGRs) and their potential for breeding purposes, aiming to promote more sustainable cropping systems as climatic shifts become more frequent and fiercer, and environmental degradation expands worldwide.

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Bhattacharjya, Birendra Kumar, Anil Kumar Yadav, Dipesh Debnath, Bhaskar Jyoti Saud, Vinod Kumar Verma, Sona Yengkokpam, Uttam Kumar Sarkar e Basanta Kumar Das. "Effect of extreme climatic events on fish seed production in Lower Brahmaputra Valley, Assam, India: Constraint analysis and adaptive strategies". Aquatic Ecosystem Health & Management 24, n. 3 (1 luglio 2021): 39–46. http://dx.doi.org/10.14321/aehm.024.03.06.

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Abstract The climate of Brahmaputra valley (located in the North-eastern Indian state of Assam) witnesses considerable changes with sub-tropical rain-storm atmosphere and has four well-defined seasons (monsoon, post-monsoon, winter and pre-monsoon) in a year. The state is experiencing extreme climatic events like erratic rainfall patterns (causing abnormally high floods) and drought-like situations in recent years, which adversely affects fish seed production thereby affecting pond aquaculture and fisheries enhancements in open-waters of the region. The present paper describes the major constraints faced by fish seed producers of the region because of extreme climatic events (abnormally high floods and prolonged dry spells) based on field studies in 27 fish seed production farms (randomly selected) located in three districts of Lower Brahmaputra Valley Zone of Assam, India. Primary data on different aspects of constraints faced by the fish seed producers because of extreme climatic events were collected and analysed. Rank Based Quotient values were calculated, based on ranks given by the fish seed producers for each constraint to prioritize them. Dominant constraint related to abnormally high floods faced by the fish seed producers was ‘loss of brood stock’ (Rank based quotient = 99.1) whereas the least important constraint was ‘entry of weeds/macrophytes’ during floods (Rank Based Quotient = 25.5). Constraints related to drought-like situations ranged from the least important ones like ‘low milt production of male brood fishes’ that had the lowest value (12.5) to the over-arching constraint of ‘inadequate water depth in fish ponds’ during pre-monsoon and prolonged dry spells (Rank Based Quotient = 100.0). Adaptive strategies developed by fish seed producers of the study region to overcome the major constraints have been outlined in the paper. The need for developing improved risk management at macro-level through appropriate policy support to fish seed producers in the fish-deficit region and suggested policy support measures for ensuring sustainability are discussed.

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Moomen, Abdul-Wadood. "AIR TRANSPORT IN GHANA: SOME CLIMATIC CONSTRAINTS". Aviation 16, n. 3 (2 ottobre 2012): 88–95. http://dx.doi.org/10.3846/16487788.2012.732323.

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Understanding a definite geographic context is essential for effective air transport management. To date, the consequences of changing weather conditions and climate on the transportation sector in Ghana has been grievous to the economy of the country. Unfortunately, the impact of climate change on the aviation industry has received very little attention in Ghanaian literature. Meanwhile, it is widely known that transport systems on the whole perform poorly under adverse weather and climatic conditions. This paper seeks to reflect a growing orientation in research and philosophy in the field of air transport and severe weather and climatic constraints. Understanding under-lying principles of climatic conditions and weather is essential to air navigation in Ghana. Clear air turbulence, ceiling and visibility, thunderstorms, electrical phenomenon, climate-induced seasonal variations, and vegetation are some of the threats to air transport across Ghana's airspace. Information is derived from literature surveys, workplace counts, and an aviation researcher. Overall, large information technology investments, consolidation, and re-structuring are all major issues that must be addressed by stakeholders ambitious to stay afloat and competitive in Ghana's airspace.

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Brown, Carissa D., e Mark Vellend. "Non-climatic constraints on upper elevational plant range expansion under climate change". Proceedings of the Royal Society B: Biological Sciences 281, n. 1794 (7 novembre 2014): 20141779. http://dx.doi.org/10.1098/rspb.2014.1779.

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We are limited in our ability to predict climate-change-induced range shifts by our inadequate understanding of how non-climatic factors contribute to determining range limits along putatively climatic gradients. Here, we present a unique combination of observations and experiments demonstrating that seed predation and soil properties strongly limit regeneration beyond the upper elevational range limit of sugar maple, a tree species of major economic importance. Most strikingly, regeneration beyond the range limit occurred almost exclusively when seeds were experimentally protected from predators. Regeneration from seed was depressed on soil from beyond the range edge when this soil was transplanted to sites within the range, with indirect evidence suggesting that fungal pathogens play a role. Non-climatic factors are clearly in need of careful attention when attempting to predict the biotic consequences of climate change. At minimum, we can expect non-climatic factors to create substantial time lags between the creation of more favourable climatic conditions and range expansion.

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Kumar, Manoj, S. N. Ojha, Arpita Sharma e Raushan Kumar. "A study on constraints in adoption of scientific aquaculture practices". Journal of Applied and Natural Science 6, n. 2 (1 dicembre 2014): 696–700. http://dx.doi.org/10.31018/jans.v6i2.520.

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A study was undertaken to ascertain constraints faced by fish farmers in adoption of scientific aquaculture practices in East Champaran and West Champaran districts of Bihar. Information from 144 respondents was collected and analysed by calculating the Rank Based Quotient (RBQ) values. RBQ value for constraint faced by farmers were extreme climatic conditions (84.03), less extension programs and technical support (78.47), lack of contact with extension personnel’s (71.33), lack of awareness about scientific culture practices (65.28), inadequate credit facility (60.42), labour scarcity (57.64) and higher cost of material input (52.08).These constraints could be categorised under five heads namely extension constraints, financial constraints, production constraints, marketing constraints and social constraints. Average RBQ value for constraints related to extension was found to be 71.76 and ranked first. This was followed by financial constraint with RBQ value of 52.78. Production related constraint ranked third with an average RBQ value of 49.3 followed by marketing (32.87) and social constraints(27.08). Hypothesis that there is no significant difference with reference to rankings of constraints was tested by single factor ANOVA. Null hypothesis was rejected as Ftab=3.48>FNcal=2.61 with df=4 at 5% level of significance. There was a significant difference with reference to rankings of constraints. As the extension related constraints had the highest average RBQ value, it is clear that there is an urgent need of making effective strategy, engaging more fisheries extension professionals in this field along with capacity development of the existing extension professionals.

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Tsai, J. "Climatic Constraints on Rice Production in Taiwan". Journal of Agricultural Meteorology 52, n. 5 (1997): 823–32. http://dx.doi.org/10.2480/agrmet.52.823.

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Laughlin, Daniel C., Peter Z. Fulé, David W. Huffman, Joseph Crouse e Etienne Laliberté. "Climatic constraints on trait-based forest assembly". Journal of Ecology 99, n. 6 (8 settembre 2011): 1489–99. http://dx.doi.org/10.1111/j.1365-2745.2011.01885.x.

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Khan, Naheed Zia, Karamat Ali e John R. Anania. "Productivity Constraints of Cholistani Farmers". Pakistan Development Review 35, n. 4II (1 dicembre 1996): 549–63. http://dx.doi.org/10.30541/v35i4iipp.549-563.

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This paper examines the factors behind low crop yield in Cholistan. Both the quantitative and qualitative analysis show how the low levels of agricultural productivity in this area may be linked to material and climatic factors. The quantitative analysis is mainly focused on physical factors. The qualitative analysis, however, emphasises that relative inefficiency of agricultural activity in Cholistan reflects the influence of physical, economic, social and, most importantly, climatic factors. The quantitative findings provide valuable insight into various ‘sources of productivity’ in terms of acreage effect, capital input effect and irrigation water availability effect. The size of the positive and significant coefficients on these variables suggest the extent to which one or the other variable effect is prominent in improving the crop yield. The qualitative analysis examines multiple interrelated factors which can be blamed on for relative inefficiency of Cholistani farmers. The hot climate of the area turns out to be the most critical variable in this analysis. Many specific technological drought-mitigating measures are proposed. However, for consistent policy formulation, a thorough study and quantitative evaluation of the potential and practicality of these measures in Cholistan is suggested.

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Lawson, T. L., e M. V. K. Sivakumar. "Climatic constraints to crop production and fertilizer use". Fertilizer Research 29, n. 1 (luglio 1991): 9–20. http://dx.doi.org/10.1007/bf01048985.

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Mongwe, Precious, Matthew Long, Takamitsu Ito, Curtis Deutsch e Yeray Santana-Falcón. "Climatic controls on metabolic constraints in the ocean". Biogeosciences 21, n. 15 (1 agosto 2024): 3477–90. http://dx.doi.org/10.5194/bg-21-3477-2024.

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Abstract. Observations and models indicate that climate warming is associated with the loss of dissolved oxygen from the ocean. Dissolved oxygen is a fundamental requirement for heterotrophic marine organisms (except marine mammals) and, since the basal metabolism of ectotherms increases with temperature, warming increases organisms' oxygen demands. Therefore, warming and deoxygenation pose a compound threat to marine ecosystems. In this study, we leverage an ecophysiological framework and a compilation of empirical trait data quantifying the temperature sensitivity and oxygen requirements of metabolic rates for a range of marine species (“ecotypes”). Using the Community Earth System Model Large Ensemble, we investigate how natural climate variability and anthropogenic forcing impact the ability of marine environments to support aerobic metabolisms on interannual to multi-decadal timescales. Warming and deoxygenation projected over the next several decades will yield a reduction in the volume of viable ocean habitats. We find that fluctuations in temperature and oxygen associated with natural variability are distinct from those associated with anthropogenic forcing in the upper ocean. Further, the joint temperature–oxygen anthropogenic signal emerges sooner than temperature and oxygen independently from natural variability. Our results demonstrate that anthropogenic perturbations underway in the ocean will strongly exceed those associated with the natural system; in many regions, organisms will be pushed closer to or beyond their physiological limits, leaving the ecosystem more vulnerable to extreme temperature–oxygen events.

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Tesi sul tema "Climatic constraints"

Gorst, Ashley. "Assessing climatic and technological constraints to agricultural productivity in South Asia". Thesis, London School of Economics and Political Science (University of London), 2017. http://etheses.lse.ac.uk/3613/.

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This thesis comprises of four essays that seek to advance understanding of the role that climatic constraints have on agricultural productivity in India and Pakistan. This work emphasises that the constraints posed to agricultural production must be understood within the context of an evolving set of environmental and technological conditions. The thesis employs empirical methods to understand these relationships, where particular emphasis is placed on methods suitable for learning about the challenges agriculture will face in the future. The first chapter studies the impact of climate change on rice yields in India by modelling the inter-annual distribution of yield conditional on projected temperature increases. The results suggest a decrease in average yield and a substantial increase in the probability of low yields. It is also shown that yields have become increasingly resilient to heat over time. The second chapter studies the e↵ect of drought on cereal production in India by estimating thresholds of drought impact. By examining thresholds over time, evidence is found of decreasing average impacts, but with evidence of an abrupt increase in average drought impacts in more recent years. Thresholds of precipitation are also estimated, indicating substantial heterogeneity in resilience to drought across crop types and regions of India. The third chapter examines how changes in agricultural technology brought about by the Green Revolution a↵ected the relative importance of agro-climatic factors in determining crop yields. Using a detailed measure of crop suitability it is found that yields increased relatively more in areas of higher suitability, indicating complementarity between agricultural technologies and favourable agro-climatic characteristics. The final chapter uses farm-level data from a specifically-designed survey to assess the impact and determinants of climate change adaptation strategies on crop productivity in Pakistan. Adaptation has a beneficial e↵ect on rice yields, but not on wheat yields. This chapter also finds that a number of household and institutional factors are strongly related to whether households have adapted to climate change.

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Scalici, Giovanni. "Physiological and productive responses of Miscanthus genotypes to different climatic constraints in Mediterranean environment". Doctoral thesis, Università di Catania, 2014. http://hdl.handle.net/10761/1603.

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Strong global growth and development has increased demand for energy to refine, manufacture and transport products to support the lifestyles of an increasingly developing and globalized world. In recent decades, fossil fuels have become important sources of energy. However, with increasing demand, there has been developing concern over the sustainability of fossil fuels relating to their potential future sources and harmful byproducts of use, specifically large net carbon releases, which has spurred interest towards the use of alternative renewable energy sources. Potential alternatives are available including wind, solar, hydro, and biomass, all of which are touted to have greater environmental benefits relative to fossil fuels. There has been increasing interest in the use of perennial grasses as energy crops in the US and Europe since the mid-1980s. The characteristics which make perennial grasses attractive for biomass production are their high yield potential, the high contents of lignin and cellulose of their biomass and their generally anticipated positive environmental impact. For this purpose, three different researches were carried out with the aim of studying i) the adaptation and biomass production potential of 18 Miscanthus accessions, representing 5 Miscanthus species, collected from a wide geographical range (Numata, 1974) for suitability to semi-arid Mediterranean climates; ii) the effect of harvest time (autumn and winter time) on biomass yield, morph-biometric characters, moisture content, cellulose, hemicelluloses and lignin contents for second generation bioethanol production and ash content for combustion purposes in a long term plantation of Miscanthus x giganteus in a Mediterranean environment; iii) the effect of heat stress, in controlled-environment, on 5 Miscanthus genotypes, coming from the Miscanthus germplasm collection at Institute of Biological, Environmental and Rural Sciences (IBERS) of the Aberystwyth University Wales UK, to identify if the high temperature have a negative effect on the growth, partitioning and physiology of Miscanthus plants. Results suggest that some Miscanthus accessions are suitably adapted to maintain high biomass in a semi-arid Mediterranean environment and that the most commonly available commercial Miscanthus genotypes (M. x giganteus and Goliath) are not well adapted to the Mediterranean climate or environments where water is a limiting factor, and there are other Miscanthus accessions that produce high biomass in water limited semi-arid regions. Long term Miscanthus plantations strictly depend by the thermopluviometric trend of the growing season, decreasing biomass yield as rainfall reduces and the biomass for specific end uses presents higher quality (in terms of more hemicellulose and cellulose content than ash content), with winter harvest. Relative to low temperature, high temperature decreased the plant height (~48%), above-ground dry biomass (~66%), below-ground dry biomass (~26%) and photosynthetic response to absorbed light (~13%). The most widely available and commonly used variety of Miscanthus is sensitive to high temperatures and there are other genotypes that have a higher capacity for carbon assimilation in high temperature environments.

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Eakin, Hallie Catherine 1970. "Adapting to climatic variability in Tlaxcala, Mexico: Constraints and opportunities for small-scale maize producers". Thesis, The University of Arizona, 1998. http://hdl.handle.net/10150/278686.

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Through semi-structured interviews with Mexican climatologists and farmers and others in the agricultural sector in Tlaxcala, Mexico, this study explored how uncertainties posed by both variable climatic and changing political-economic conditions affect the vulnerability of small-scale maize producers. The objective of my research was to assess whether and how small-scale Tlaxcaltecan farmers could use long-lead forecasts to mitigate climatic uncertainty. The potential effectiveness of the climate forecasts was evaluated within the context of cultural, political, social and economic factors that influence the decision-making of smallholder farmers. This research determined that the vulnerability of small-scale producers in Tlaxcala is more a function of political-economic uncertainty than of physical circumstances. While farmers employ complex methods for anticipating climatic events based on religious beliefs and local knowledge, their ability to adapt is constrained by lack of resources. As a result, the success of the forecasts in mitigating small-farmer vulnerability will be limited.

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Techoro, Prosper Somah Verfasser], e Michael [Akademischer Betreuer] [Schmidt. "Climatic change impacts on subsistence agriculture in the Sudano-Sahel Zone of Cameroon - constraints and opportunities for adaptation / Prosper Somah Techoro. Betreuer: Michael Schmidt". Cottbus : Universitätsbibliothek der BTU Cottbus, 2013. http://d-nb.info/1038211085/34.

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Benzabih, Hosney A. "Environmental and socio-economic constraints on rain-fed agricultural land settlement projects in marginal climatic zones : a case study of the Jabel al-Akhdar Upland, Libya". Thesis, SOAS, University of London, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267232.

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Dibacto, Kamwa Stéphane. "Dynamique de construction et démantèlement des volcans tertiaires et quaternaires des Carpates par des approches géomorphologiques et géochronologiques Growth and erosion constraints of the East Carpathians volcanoes by numerical models: tectonic and climatic implications Eruptive history of the Late Quaternary Ciomadul (Csomád) volcano, East Carpathians, part II: magma output rates Eruptive history of the Late Quaternary Ciomadul (Csomád) volcano, East Carpathians I: timing of lava dome activity constrained by the unspiked K-Ar method". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS144.

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Dans cette thèse, 47 nouveaux âges ont été obtenus par la technique Cassignol-Gillot. La très bonne reproductibilité des âges obtenus, ajoutée à une stricte cohérence observée entre les édifices volcaniques, supporte l'utilisation de la méthode K-Ar dans la datation des laves des Carpates orientales (Călimani-Gurghiu-Harghita ; CGH) et des dépôts d'ignimbrite du Miocène des Carpates occidentales (les monts de Mátra et Bükk). Dans la partie orientale de la chaîne, les données géochronologiques ont été combinées avec des analyses géomorphologiques pour contraindre l'histoire volcanique et calculer leur taux de construction et d'érosion. Parallèlement, dans la partie occidentale de la chaîne, les données géochronologiques obtenues ont été combinées aux données paléomagnétiques disponibles pour affiner leur stratigraphie. La chaîne des Carpates orientales a connu une migration de son activité éruptive le long de l’arc du Miocène au Quaternaire. Ici, une méthodologie novatrice et complexe apporte de nouvelles contraintes géochronologiques et géomorphologiques sur l'évolution des 20 volcans de la chaîne. Les nouveaux âges ont permis de contraindre leur durée d’activité Par exemple Seaca-Tătarca (6,79-6,47 Ma), Vârghiş (5,47-4,61 Ma) ou de dater l’activité volcanique la plus récente de Călimani. Pour le complexe volcanique de Ciomadul, composé d'une douzaine de dômes de lave, l’activité volcanique a été contrainte entre 704±18 et 28±1ka (<1 Ma) interrompue de périodes de repos. En parallèle, des reconstructions numériques de paléo-topographies volcaniques ont été réalisées dans le but de quantifier leur forme à la fin de leur construction. Les résultats déduits de nos reconstructions ont donné un volume total de matériel émis de 2300km3 sur toute la chaîne avec, à l’échelle de chaque volcan, une large gamme de variation de leur taille (3±3 à 592±115 km³). Ces volumes montrent une nette diminution du nord au sud de la chaîne avec des valeurs de 910, 880, 279 et 165 km³ pour des secteurs géographiques de Călimani, Gurghiu, North Harghita et South Harghita respectivement. Combinés aux âges, ces volumes ont permis de calculer un taux de construction moyen de 200km³/Ma pour toute la chaîne, représenté par deux groupes distincts ; un groupe caractérisé par des taux de construction de 137 km³/Ma caractéristiques des vieux volcans (11-3,6 Ma) suivi d'un groupe avec des taux de construction de 28km³/Ma pour les volcans Plio-Quaternaires. La comparaison des volcans reconstruits et ceux actuels a permis de calculer un volume érodé total de 524±125km³, correspondant à une dénudation moyenne de 22% et à un taux d'érosion moyen de 20m/Ma pour la chaîne de CGH. Suite aux fluctuations climatiques enregistrées le long de cette chaîne, les taux d'érosion caractéristiques de ces grandes périodes climatiques ont été calculés dans le but de montrer le rôle qu’a joué le climat sur les taux d’érosion. Le taux d'érosion le plus élevé de 38m/Ma a été obtenu pour la période régie par un climat continental subtropical modéré transitionnel (9,5-8,2 Ma). Pour la période climatique continentale modérée (8,2-6,8 Ma), caractérisée par des conditions climatiques beaucoup moins humides, un taux d'érosion de 14 m/Ma est proposé. Pour la période correspondant à un climat continental avec identification de périodes semi-arides (6,8-5,8 Ma), un taux d'érosion de 7 m/Ma a été calculé. Pour les volcans Plio-Quaternaires ayant connus des cycles interglaciaires/glaciaires, un taux d'érosion de 28m/Ma a été obtenu. Une telle approche morphométrique et géochronologique quantitative démontre son efficacité à étudier le dynamisme volcanique, y compris les processus de construction et d'érosion au fil du temps. Dans la partie occidentale des Carpates, les âges obtenus sur les coulées de lave de Börzsöny contraignent sa période d'activité entre 14,3-15,1 Ma. Pour les dépôts ignimbritiques de Bükk, les résultats K-Ar évoluent entre 12,7-16,5 Ma
In this PhD thesis, 47 new ages have been obtained by the Cassignol-Gillot technique. The very good reproducibility of the ages obtained in this study, added to a strict consistency observed between the volcanic edifices, support the use of the K-Ar method in the dating of the East Carpathian lavas (Călimani-Gurghiu-Harghita) and ignimbrite deposits of the North Hungarian (Mátra and Bükk Mts. [western Carpathians]). In the Eastern part, this new geochronological dataset has been combined with geomorphological analyses to constrain the volcanic history as well as to compute construction and erosion rates of those volcanoes. In parallel, in the western part geochronological dataset has been combined with available paleomagnetic data to refine their stratigraphy. The East Carpathian volcanic range experienced an along-arc, Late Miocene to Quaternary migration of eruptive activity. Here, a novel and complex methodology are presented that yields new geochronological and geomorphological constraints on the evolution of the 20 volcanic edifices. New unspiked K-Ar ages either constrain their lifespan (6.79- 6.47 Ma for Seaca-Tătarca; 5.47- 4.61 Ma for Vârghiş) or date the youngest volcanic activity (central Călimani). For Ciomadul volcanic complex composed by a dozen of lava domes, which hosts the recent volcanic activity since the last 1 Ma, its activity has been constrained between 704± 18 ka and 28 ± 1 ka with several quiescence periods. In parallel, numerical reconstructions of volcanic paleo-topographies were performed to quantify their shape at the end of their construction stage. The inferred initial volcano size shows a wide range (3±3 to 592±115 km³), making up the four main successive volcanic segments (910, 880, 279 and 165 km³ for Călimani, Gurghiu,North Harghita and South Harghita segment, respectively) totalizing 2300 km³. Volume and age constraints allowed computing an average growth rate of 200 km³/Ma for the whole range, characterized by an initial moderate growth rate (137 km³/Ma) of the older volcanoes (11-3.6 Ma) followed by a lower growth rate (28 km³/Ma) obtained for the Plio-Quaternary volcanoes. Comparing reconstructed and current topographies yielded a total eroded volume of 524±125 km³, defining averaged denudation of 22% and a 20 m/Ma erosion rate. Erosion rates for major climatic periods were computed, which highlight the contrasting climatic contexts since 11 Ma. The highest erosion rate (38 m/Ma) occurred during a transitional moderate subtropical continental climate period (9.5-8.2 Ma). An intermediate erosion rate (14m/Ma) characterized a moderate continental climate period (8.2-6.8 Ma) when conditions became less humid. The lowest erosion rate (7 m/Ma) reflects the prevailing continental but occasionally semi-arid climate (6.8-5.8 Ma). The highest erosion rate (28m/Ma) was obtained for Plio-Quaternary times during the interglacial/glacial cycles. Such a quantitative morphometric and geochronological approach demonstrates its efficiency to study volcanic dynamism, including both constructional and erosional processes, through time. In the western part of the Carpathian range, the new ages obtained on the lava flows of Börzsöny made it possible to constraint its period of activity between 14.27 - 15.11 Ma. For the Miocene ignimbrite of Bükk foreland, the new K-Ar results range between 12.7 - 16.5 Ma

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Duhamel, Maxence. "Restitution des changements de l’hydrologie des masses d’eaux intermédiaires et profondes de la Méditerranée au cours des derniers 145 ka à partir de la mesure de la composition isotopique du Nd de foraminifères Variations in eastern Mediterranean hydrology during the last climatic cycle as inferred from neodymium isotopes in foraminifera Changes in the intermediate water masses of the Mediterranean Sea during the last climatic cycle - new constraints from neodymium isotopes in foraminifera". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASS120.

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Cette thèse vise à faire progresser notre connaissance de l’hydrologie des masses d’eaux intermédiaires et profondes de la Méditerranée au cours du dernier cycle climatique (derniers 145 ka), et de contraindre les modèles de circulation océanique ayant permis les dépôts de niveaux riches en matière organique (ORL et sapropèles). La composition isotopique en Nd (εNd) d’échantillons de foraminifères de carottes localisées à des bathymétries intermédiaires et profondes de la mer Tyrrhénienne, de l’Adriatique, de la mer Ionienne et du bassin Levantin ont été analysées. Ce travail a permis de mettre en évidence que les eaux intermédiaires et profondes de la Méditerranée Orientale sont systématiquement plus radiogéniques durant les périodes glaciaires que durant les interglaciaires. Nous avons démontré que ces changements ne peuvent pas être attribuée entièrement aux variations des apports éoliens et fluviatiles du Nord de l’Afrique mais à d’importantes modifications dans la quantité d’eau Atlantique (AW) pénétrant en Méditerranéen. Les périodes de bas niveaux marins glaciaire sont associées à une réduction des flux d’eau Atlantique à travers les détroits de Gibraltar et Siculo-tunisien en induisant des masses d’eau profonde plus radiogéniques en Méditerranée orientale. Surimposées à ces fluctuations glaciaires-interglaciaires, les périodes humides Africaines et de dépôts de sapropèles sont systématiquement caractérisées par des valeurs εNd plus radiogéniques. Cela a été attribué à l’arrêt de la convection profonde des eaux moins radiogéniques de surface associée à une augmentation du temps de contact des masses d’eaux profondes avec les sédiments radiogéniques des marges continentales du bassin Levantin. Nos résultats mettent en évidence durant les terminaisons I et II une augmentation de la contribution d’eau moins salées d’origine Nord Atlantique (MAW) d’environ 55 % pouvant avoir pré-conditionné la Méditerranée orientale plusieurs milliers d’année avant le dépôt des sapropels S1 et S5.La comparaison des enregistrements d’εNd obtenus dans les bassins Orientale et Occidentale sur le dernier cycle climatique montre un gradient d’εNd plus fort entre les deux bassins aux profondeurs intermédiaires et profondes durant les stades glaciaires. Cela est cohérent avec un échange d’eau plus faible de part et d’autre du détroit Siculo-tunisien durant les périodes de bas niveau marin glaciaire. Durant les hauts niveaux marins des périodes les interglaciaires les échanges d’eau sont au contraires plus forts entre les deux bassins induisant un transfert à la mer Tyrrhénienne des variations de la composition isotopique en Nd observée en Méditerranée orientale. Ainsi, les périodes humides africaines induisant une stratification des masses d’eaux et les dépôts de sapropèles à l’est, sont associées à des signatures d’eaux plus radiogéniques qui sont alors transportées par la LIW en Mer Tyrrhénienne. Surimposé à ces variations orbitales, des variations rapides de l’εNd ont pu être mises en évidence dans le chenal de Corse. Chaque événements froids des hautes latitudes de l’hémisphère Nord (Younger Dryas et événements de Heinrich) se caractérisent par une LIW plus radiogénique dans la mer Tyrrhénienne impliquant une réduction de la formation d’eau intermédiaire dans le Golfe du Lion (lié à de plus forts apports d’eaux douces depuis l’Atlantique lors des événements de Heinrich) et/ou une production plus importante de LIW en Méditerranée orientale (lié à un refroidissement de la surface du Nord de la Méditerranée lors des événements de Heinrich)
This thesis aims to advance our knowledge of the hydrology of the intermediate and deep water masses of the Mediterranean during the last climatic cycle (last 145 ka), and to constrain the ocean circulation models that allowed the deposition of organic matter-rich sediments (ENT and sapropels). The Nd isotopic composition (εNd) of foraminifera samples in cores located at intermediate and deep bathymetries of the Tyrrhenian Sea, the Adriatic Sea, the Ionian Sea and the Levantine Basin were analyzed. This work allowed to highlight that the intermediate and deep waters of the Eastern Mediterranean are systematically more radiogenic during the glacial stadiums than during the interglacials. We have shown that these changes cannot be entirely attributed to variations in dust and river inputs from northern Africa but to significant changes in the amount of Atlantic (AW) water entering the Mediterranean. Periods of low sea ice levels are associated with a reduction in Atlantic water flows through the straits of Gibraltar and Siculo-Tunisia by inducing more radiogenic deep-water masses in the eastern Mediterranean. Superimposed on these glacial-interglacial fluctuations, African humid periods and sapropel deposits are systematically characterized by more radiogenic εNd values. This has been attributed to the cessation of deep convection of less radiogenic surface water associated with an increase in the contact time of deep-water bodies with radiogenic sediments from the continental margins of the Levantine basin. Our results highlight during terminations I and II an increase in the contribution of less salty water of North Atlantic origin (MAW) of around 55% which may have pre-conditioned the eastern Mediterranean several thousand years before the deposit S1 and S5 sapropels. A comparison of the εNd recordings obtained in the Eastern and Western basins over the last climate cycle shows a stronger gradient of εNd between the two basins at intermediate and deep depths during the glacial stadiums. This is consistent with a weaker water exchange across the Siculo-Tunisian Strait during periods of low sea ice. On the contrary, during the high sea levels of the interglacial periods, water exchanges are stronger between the two basins, inducing a transfer to the Tyrrhenian Sea of variations in the isotopic composition of Nd observed in the eastern Mediterranean. Thus, the African wet periods inducing a stratification of the water masses and the deposits of sapropels in the east, are associated with signatures of more radiogenic waters which are then transported by the LIW in the Tyrrhenian Sea. Superimposed on these orbital variations, rapid variations in εNd could be highlighted in the Corsica channel. Each cold event in the high latitudes of the Northern Hemisphere (Younger Dryas and Heinrich events) is characterized by a more radiogenic LIW in the Tyrrhenian Sea involving a reduction in the formation of intermediate water in the Gulf of Lion (linked to more strong freshwater inflows from the Atlantic during the Heinrich events) and / or a greater production of LIW in the eastern Mediterranean (linked to a cooling of the northern Mediterranean surface during the Heinrich events)

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Sansom, Philip George. "Statistical methods for quantifying uncertainty in climate projections from ensembles of climate models". Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/15292.

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Appropriate and defensible statistical frameworks are required in order to make credible inferences about future climate based on projections derived from multiple climate models. It is shown that a two-way analysis of variance framework can be used to estimate the response of the actual climate, if all the climate models in an ensemble simulate the same response. The maximum likelihood estimate of the expected response provides a set of weights for combining projections from multiple climate models. Statistical F tests are used to show that the differences between the climate response of the North Atlantic storm track simulated by a large ensemble of climate models cannot be distinguished from internal variability. When climate models simulate different responses, the differences between the re- sponses represent an additional source of uncertainty. Projections simulated by climate models that share common components cannot be considered independent. Ensemble thinning is advocated in order to obtain a subset of climate models whose outputs are judged to be exchangeable and can be modelled as a random sample. It is shown that the agreement between models on the climate response in the North Atlantic storm track is overestimated due to model dependence. Correlations between the climate responses and historical climates simulated by cli- mate models can be used to constrain projections of future climate. It is shown that the estimate of any such emergent relationship will be biased, if internal variability is large compared to the model uncertainty about the historical climate. A Bayesian hierarchical framework is proposed that is able to separate model uncertainty from internal variability, and to estimate emergent constraints without bias. Conditional cross-validation is used to show that an apparent emergent relationship in the North Atlantic storm track is not robust. The uncertain relationship between an ensemble of climate models and the actual climate can be represented by a random discrepancy. It is shown that identical inferences are obtained whether the climate models are treated as predictors for the actual climate or vice versa, provided that the discrepancy is assumed to be sym- metric. Emergent relationships are reinterpreted as constraints on the discrepancy between the expected response of the ensemble and the actual climate response, onditional on observations of the recent climate. A simple method is proposed for estimating observation uncertainty from reanalysis data. It is estimated that natural variability accounts for 30-45% of the spread in projections of the climate response in the North Atlantic storm track.

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Nettleton, Stuart John. "Benchmarking climate change strategies under constrained resource usage /". Electronic version, 2009. http://utsescholarship.lib.uts.edu.au/iresearch/scholarly-works/handle/2100/1012.

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Häckner, Lina. "Climate Change and Agriculture in Babati : Awareness Strategies Constrains". Thesis, Södertörn University College, School of Life Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-2685.

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Climate change caused by green house gas emissions, mainly carbon dioxide, is today’s most debated environmental issue. The United Nations Framework Convention on Climate Change, with the legally binding Kyoto protocol, is the emission regulatory framework. Tanzania has ratified both the conventions supporting carbon reductions.

Tanzania has a very varied climate with two rainfall regimes dominating the country, bimodal and unimodal. Scientific literature predicts a 2,2-4°C average increase in temperature for Tanzania, all studies also predict a higher increase in the cooler period and lower in the warm period. Rainfall predictions are less certain but in general a 10 % average increase is expected but the distribution uneven, both between rain periods and geographically. Tanzanian reports estimate a 5-45 % increase in rainfall in bimodal regions and a 5-15 % decrease in unimodal regions. The distribution of increase in bimodal regions will be uneven, with an increase in the long rain period and a decrease in the short rain period.

Agriculture is indisputably the most important source of income in Tanzania standing for 80% of employment and 50% of GNP. Climate change will therefore inevitably affect the economy and livelihood of people. Developing countries are also more vulnerable due to lower adaptation capacity. Effects on Tanzania are predicted to be both positive and negative. Maize production, the major staple, is predicted an average 33% decline while cash crops like coffee and cotton are predicted to increase. To be able to adapt there first has to be a perception of need to adapt, adaption strategies then have to be developed and barriers worked through. The purpose of this thesis is to investigate the level of awareness, strategies and barriers existing for adaption to climate change on national, regional and local level, Tanzania nationally and Babati regionally and locally. The research questions are; How do people perceive climate change? What are the strategies for adapting to climate change? What are the barriers for adaption to climate change? At national level policy framework and strategies were used to answer the research questions. At regional and local level a field study was conducted in Babati to answer the research questions at these levels.

The study showed that Tanzania nationally has declared their conviction in climate change and state that the issue has to be addressed. Agriculture is identified as one of the most vulnerable areas however climate change is not mainstreamed into agricultural and environmental policy framework. In Babati district no policy was found on climate change and official perception varied. Concerns were related to timing and amount of rainfall, the results were the same for farmers. Global climate change was also known for both studied groups and existed as a parallel truth with the local reason for changes. A number of adaption strategies are also identified nationally, both used and potential, where small scale irrigation is the primary adaptive step. Switching to draught resistant crops is also prioritized in the North eastern region. In Babati adaption strategies were promoted, even though there was not a general policy or perception, by officials to switch to short-term crops and planting of trees. Switching cops was also the most commonly used strategy by farmers along with traditional diversification. Nationally a large number of barriers are also identified including, lack of funding, poverty, HIV, lack of infrastructure and analytic capacity. Officials in Babati also mentioned the lack of money, deforestation, lack of clouds, education, irrigation and seeds. The farmers in Babati were not so clear about what they needed to adapt, irrigation, livestock backup, diversification and switching crops were mentioned, not differing much from used strategies.

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Libri sul tema "Climatic constraints"

International Symposium on the Constraints and Possibilities of Ruminant Production in the Dry Subtropics (1988 Cairo, Egypt). Ruminant production in the dry subtropics: Constraints and potentials : proceedings of the international symposium on the constraints and possibilities of ruminant production in the dry subtropics (MOA of Egypt, ESAP, EAAP, FAO, ICAMAS, WAAP), Cairo, Egypt, 5-7 November 1988. Wageningen, Netherlands: Pudoc, 1989.

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T, Craswell E., Simpson J, Australian Centre for International Agricultural Research. e Southern African Centre for Cooperation in Agricultural Research., a cura di. Soil fertility and climatic constraints in dryland agriculture: Proceedings of ACIAR/SACCAR Workshop held at Harare, Zimbabwe, 30 August-1 September 1993. Canberra: Australian Centre for International Agricultural Research, 1994.

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Andreas, Schäfer, a cura di. Transportation in a climate-constrained world. Cambridge, MA: MIT Press, 2009.

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Mbeva, Kennedy, Reuben Makomere, Joanes Atela, Victoria Chengo e Charles Tonui. Africa’s Right to Development in a Climate-Constrained World. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-22887-2.

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James, Aronson, Di Castri Francesco e Roy Jacques, a cura di. Time scales of biological responses to water constraints: The case of Mediterranean biota. Amsterdam: SPB Academic Pub., 1995.

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Washington (State). Department of Ecology. Growing Washington's economy in a carbon constrained world: A comprehensive plan to address the challenges and opportunities of climate change. Olympia, Wash: Washington State Dept. of Ecology, 2008.

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Kumar, Anjali. Enterprise size, financing patterns, and credit constraints in Brazil: Analysis of data from the investment climate assessment survey. Washington, D.C: International Bank for Reconstruction and Development/World Bank, 2005.

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Manuela, Francisco, e World Bank, a cura di. Enterprise size, financing patterns, and credit constraints in Brazil: Analysis of data from the investment climate assessment survey. Washington: World Bank, 2005.

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Barry, John. The politics of actually existing unsustainability: Human flourishing in a climate-changed, carbon constrained world. New York: Oxford University Press, USA, 2012.

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Chea, Yim. Fish exports from the Great Lake to Thailand: An analysis of trade constraints, governance, and the climate for growth. Phnom Penh: Cambodia Development Resource Institute, 2003.

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Capitoli di libri sul tema "Climatic constraints"

Lautenschlager, M., e E. Maier-Reimer. "OGCM-constraints to PM’s". In Long-Term Climatic Variations, 491–510. Berlin, Heidelberg: Springer Berlin Heidelberg, 1994. http://dx.doi.org/10.1007/978-3-642-79066-9_23.

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Stewart, Simon. "Healthy Climatic Adaption and Climate Change". In Sustainable Development Goals Series, 33–52. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-73106-8_3.

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AbstractHaving described and explored the global to individual context of climate change and health, this chapter now explores the biological imperative of any organism to maintain homeostasis. As a key function of this imperative, in humans, the cardiovascular system plays a key role in maintaining homeostasis. Over time we (humans) have overcome many of the biological limitations/constraints of these protective mechanisms through a combination of behavioural, cultural and technological adaptations—thereby allowing us to migrate and thrive in nearly every corner of the world. Within this biological to historical context, rapid climate change (through exposure to more weather extremes) is now challenging the limits of our ability to maintain homeostasis. How the opposing forces of human adaptability, maintaining thermoregulation and increasing climatic provocations to health plays out in vulnerable individuals and communities (from those living in poverty to older individuals living with chronic heart disease) will provide important context to later chapters.

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Lawson, T. L., e M. V. K. Sivakumar. "Climatic constraints to crop production and fertilizer use". In Alleviating Soil Fertility Constraints to Increased Crop Production in West Africa, 33–44. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3224-4_4.

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Schaefer, Carlos Ernesto Gonçalves Reynaud, José João Lelis Leal de Souza, Fábio Soares de Oliveira, Guilherme Resende Corrêa e Elpídio Inácio Fernandes Filho. "The Geological, Geomorphological, Climatic, and Hydrological Background of Tropical Regoliths and Hostile Subsoils: The Brazilian Landmass". In Subsoil Constraints for Crop Production, 11–52. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-00317-2_2.

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Neilson, Ronald P. "Climatic Constraints and Issues of Scale Controlling Regional Biomes". In Ecotones, 31–51. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-9686-8_3.

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Hochman, Z., e K. R. Helyar. "Climatic and Edaphic Constraints to the Persistence of Legumes in Pastures". In Persistence of Forage Legumes, 177–203. Madison, WI, USA: American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, 2015. http://dx.doi.org/10.2134/1989.persistenceofforagelegumes.c13.

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Mitchell, David J. "Climatic Constraints to Crop Production in the Red Soils Area of Southern China". In The Red Soils of China, 111–27. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-2138-1_8.

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Reddy, P. Sanjana. "Ideotype breeding for improving yield in sorghum: recent advances and future perspectives." In Molecular breeding in wheat, maize and sorghum: strategies for improving abiotic stress tolerance and yield, 498–516. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789245431.0029.

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Abstract This chapter focuses on ideotype breeding for improving the yield and related traits, abiotic stress resistance, and quality of grain and forage sorghum. Ideotype breeding involves defining and breeding for the target traits to reach the objectives and differs from classical plant breeding which focuses more on yield. Due to diversification of cropping systems and ever-changing climatic conditions, change in farmers' preferences and several production constraints, breeders need to focus on more traits simultaneously.

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Lehmann, Marco M., Philipp Schuler, Marc-André Cormier, Scott T. Allen, Markus Leuenberger e Steve Voelker. "The Stable Hydrogen Isotopic Signature: From Source Water to Tree Rings". In Stable Isotopes in Tree Rings, 331–59. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92698-4_11.

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AbstractThe hydrogen isotopic signature (δ2H) of water in trees contains information on plant functional responses to climatic changes and on the origin of the water. This is also true for the non-exchangeable hydrogen isotopic signature (δ2HNE) of plant organic matter, which contains additional physiological and biochemical information that can be dated to specific years if extracted from annual rings of trees. Despite this potential for gaining unique insights from δ2HNEof tree-ring cellulose (δ2HTRC), it has not been widely used compared to other isotope signals, likely due to challenging methodological constraints and interpretations of these isotopic signals. In this chapter, we first summarize hydrogen isotope (2H-) fractionation that occurs between source water and tree rings and review methods (e.g. nitration, equilibration, position-specific applications) and calculations to determine δ2HNE in tree material. Building upon a summary of the current state of knowledge, this chapter also provides an exhaustive synthesis of δ2HTRC papers, applications, and associated data from approximately 180 sites across the globe (paired with modelled precipitation δ2H values and climate data). The data allow us to investigate the hydrological-climatic effects driving δ2HTRC pattern on a global scale, the relationship of hydrogen with oxygen isotopes in the same tree-ring material, as well as the influence of physiological-biochemical effects (e.g., species differences, tree growth) that appear to be more important on local or temporal scales than on a large spatial scales. Thus, when local hydro-climatic influences on source water δ2H can be isolated, δ2HTRC gives novel insights on tree physiological responses to abiotic and biotic stresses. We conclude that the growing constellation of tree-ring metrics, including advancements in 2H-processing (i.e., equilibration techniques allowing rapid determinations of δ2HNE) and further refinements to the understanding of post-photosynthetic 2H-fractionations will together provide many new opportunities to understand past climates and ecophysiology by using δ2H in tree rings.

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Baruah, Ujjal Deka, Nitashree Mili, Rudrakshi Gogoi e Mayuri Chetia. "Agro-Climatic Constraints and the Adaptive Empirical Knowledge System of Indigenous Farmers in Assam, India". In Traditional Ecological Knowledge of Resource Management in Asia, 333–48. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-16840-6_20.

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Atti di convegni sul tema "Climatic constraints"

Arwa, Erick O., e Kristen R. Schell. "Modeling the Maximization of Waste Heat Use in a Liquid Solvent Direct Air Capture Plant Through Hydrogen Production". In Foundations of Computer-Aided Process Design, 403–8. Hamilton, Canada: PSE Press, 2024. http://dx.doi.org/10.69997/sct.119908.

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Direct air capture (DAC) of carbon dioxide is a promising technology to enable climate change mitigation. The liquid solvent DAC (LSDAC) process is one of the leading technologies being piloted. However, LSDAC uses a high-temperature regeneration process which requires a lot of thermal energy. Although current LSDAC designs incorporate pre-heat cyclones and a heat recovery steam generator to enable heat recovery, these do not maximize the use of the heat in the products of calcination. In this paper, a linear optimization model is developed to minimize energy cost in a LSDAC that is powered by renewable energy and natural gas. First, the material flow network is modified to include a heat exchanger (HX) and water supply to a proton exchange membrane (PEM) electrolyser. Mass and energy balance constraints are then developed to include the water flow as well as the energy balance at the PEM and the HX. Results show that about 911 tonnes of hydrogen could be produced over 336 hours of operation using a 136MW PEM. Further analysis reveals that hydrogen production is only prioritized if the value is higher than the cost of natural gas.

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Patel, Jigisha, Brijesh Vala e Makhduma Saiyad. "LSTM-RNN Combined Approach for Crop Yield Prediction On Climatic Constraints". In 2021 5th International Conference on Computing Methodologies and Communication (ICCMC). IEEE, 2021. http://dx.doi.org/10.1109/iccmc51019.2021.9418231.

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Celis, Anneli Maricielo Cárdenas, Danilo Augusto Oliveira de Barros, Ana Karina Nascimento Silva Rodrigues, André da Costa Leite e José Walter Cárdenas Sotil. "The importance of the correct use of passive strategies to the hot and humid climate: The case of teaching Environmental Comfort in the Course of Architecture and Urbanism at UNIFAP". In ENSUS2023 - XI Encontro de Sustentabilidade em Projeto. Grupo de Pesquisa Virtuhab/UFSC, 2023. http://dx.doi.org/10.29183/2596-237x.ensus2023.v11.n2.p335-347.

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Making architectonic or urbanistic projects adequate to the climatic conditions is the first step that every designer should take into consideration. Often, architectural patterns are observed in various climatic contexts, disregarding the characteristics of the region, finding the same form, materials, and orientation at different latitudes in Brazil. Therefore, the objective of the present investigation, is to bring to discussion what several authors approach about recommendations for the hot and humid climate and to emphasize, that architecture must play the fundamental role of protection, or filter of the environmental elements that affect the well-being of individuals. The main references mentioned are discussions of authors who are present in the teaching references of the subject Environmental Comfort of the Architecture and Urbanism Course of the Federal University of Amapá (UNIFAP) and the production of sketches and authorial schemes carried out by the Habitar Amazônia Research Group in the development of undergraduate research and publications. With this, it seeks to bring the survey of the main passive strategies to the hot and humid climate, addressing constraints such as ventilation, shade, natural lighting, surroundings, orientation and volumetry, walls and roofs, and materials, so that students can have a database in a didactic way in project design.

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Gupta, Sanjeev, Ajit Singh, Jan-Pieter Buylaert, Rajiv Sinha, Alexander L. Densmore, Suneel Joshi, Andrew Murray, Philippa Mason, Andrew Carter e W. M. Van Dijk. "CHRONOLOGICAL CONSTRAINTS ON FLUVIAL FAN STRATIGRAPHY IN THE NW GANGES BASIN, INDIA, REVEAL AUTOGENIC AND CLIMATIC CONTROLS ON FAN EVOLUTION". In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-286817.

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Rooney, Alan D., Justin V. Strauss, Phoebe Cohen, Daniel Condon e Mark D. Schmitz. "NEW RE-OS AND U-PB AGE CONSTRAINTS FOR THE BIOLOGICAL INNOVATIONS AND GEOCHEMICAL AND CLIMATIC PERTURBATIONS OF THE NEOPROTEROZOIC". In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-302273.

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Arnulfi, Gianmario L., Giulio Croce e Martino Marini. "Parametric Analysis of Thermal Energy Storage for Gas Turbine Inlet Air Cooling". In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27464.

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Gas turbine efficiency and power output are strongly dependent on the inlet air condition. Thus, several authors proposed the use of different inlet air cooling systems. Such systems include, as examples, spraying water in the inflow air stream or air cooling through a chiller during GT operation. In the latter case, it is possible to operate the chiller at night time, taking advantage of the remarkable price gap between peak and off-peak hours. A parametric analysis of such a system is presented, focusing on the effect of price gap, chiller and storage design parameters and climatic conditions on the optimal sizing of the plant. Both the gas turbine performance changes, due to the different inlet conditions, and thermal losses related to the storage system are taken into account. The economic return of the system is evaluated through the year-round integral of gas turbine fuel consumption and chiller electricity requirements, for given scenarios of electricity price tag, ambient temperature and humidity profile. For different boundary conditions (market constraints and climate) the optimal configurations are identified and discussed.

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Emorine, Denis. "Railway Brake System in Nordic Countried Application in Sweden's Challenges and Constrains". In EuroBrake 2021. FISITA, 2021. http://dx.doi.org/10.46720/7529563eb2021-mfm-003.

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Manufacturing train fleets for countries that have extreme weather/climatic condition is always a specific challenge, moreover when the concerned country has a huge difference itself inside. Even under such specific constraints and conditions, the train and in particular the brake system must remain reliable and available. Some simple examples: How can we (car builders) make sure that the train will still brake if ice or snow is built up on brake acting component? Or if the exhaust of brake pipe (emergency brake) is clogged by ice?</p></li> If a train has failure between 2 far station (>250 km), it shall be able to run to reach the next (far) station. The presentation aims to: Present the fleet running locations, numbers and route distances, Present the requirements depending on the location (south vs north vs center Sweden), weather conditions (snowy, extremely cold)…, Overview of the specific solutions and features present to fit to the constrains: redundant AGTU for specific region, specific retardation test from brake and signaling system. We will present the real effect by examples of the snowy, extremely cold, humid climatic conditions: Pictures of a train with bogie completely hidden behind snow, Video of iced caliper moving by braking the ice (test bench) This will be just quick go through, since we plan a dedicated presentation for the winterization separately for the session in 2020. We will also present the specific feature of the brake and signaling system for Sweden: Retardation test. What is the aim? What is the historical development of it? How does it work? What are the attention compared to a performance test?</p></li> What are the special solutions used for adapting the retardation test from UIC to a direct brake system?

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Torralba, Jesús, Luis Á. Ruiz, Charalampos Georgiadis, Petros Patias, Rodrigo Gómez-Conejo, Natalia Verde, Maria Tassapoulou et al. "METHODOLOGICAL PROPOSAL FOR THE IDENTIFICATION OF MARGINAL LANDS WITH REMOTE SENSING-DERIVED PRODUCTS AND ANCILLARY DATA". In 3rd Congress in Geomatics Engineering. Valencia: Universitat Politècnica de València, 2021. http://dx.doi.org/10.4995/cigeo2021.2021.12729.

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The concept of marginal land (ML) is dynamic and depends on various factors related to the environment, climate, scale,culture, and economic sector. The current methods for identifying ML are diverse, they employ multiple parameters andvariables derived from land use and land cover, and mostly reflect specific management purposes. A methodologicalapproach for the identification of marginal lands using remote sensing and ancillary data products and validated on samplesfrom four European countries (i.e., Germany, Spain, Greece, and Poland) is presented in this paper. The methodologyproposed combines land use and land cover data sets as excluding indicators (forest, croplands, protected areas,impervious areas, land-use change, water bodies, and permanent snow areas) and environmental constraints informationas marginality indicators: (i) physical soil properties, in terms of slope gradient, erosion, soil depth, soil texture, percentageof coarse soil texture fragments, etc.; (ii) climatic factors e.g. aridity index; (iii) chemical soil properties, including soil pH,cation exchange capacity, contaminants, and toxicity, among others. This provides a common vision of marginality thatintegrates a multidisciplinary approach. To determine the ML, we first analyzed the excluding indicators used to delimit theareas with defined land use. Then, thresholds were determined for each marginality indicator through which the landproductivity progressively decreases. Finally, the marginality indicator layers were combined in Google Earth Engine. Theresult was categorized into 3 levels of productivity of ML: high productivity, low productivity, and potentially unsuitable land.The results obtained indicate that the percentage of marginal land per country is 11.64% in Germany, 19.96% in Spain,18.76% in Greece, and 7.18% in Poland. The overall accuracies obtained per country were 60.61% for Germany, 88.87%for Spain, 71.52% for Greece, and 90.97% for Poland.

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Alzayani, Alia, Abdulaziz Al-Qasim, Peter Birkle e Abdullah Al-Muhaideb. "An Overview of Monitoring and Surveillance Technologies for Geothermal Systems". In ADIPEC. SPE, 2023. http://dx.doi.org/10.2118/216945-ms.

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ABSTRACT One of the main drivers for climate change is greenhouse emission caused by burning fossil fuels. In order to combat climate change, geothermal energy represents a renewable and sustainable energy alternative. Geothermal power stations can reach a capacity of 1,500 MW with minimal effects on CO2- triggered climatic changes. In order to assure peak performance, avert catastrophes, and reduce environmental effects, geothermal systems must be continuously monitored and maintained under surveillance. Recent developments in monitoring and surveillance technologies have made it possible to monitor geothermal systems in real-time, giving important insights into their operation and enabling the early identification of potential concerns. These include seismic networks, piezometer, geochemical, gravity measurements, tracer tests, corrosion probes, and fiber optics. This paper provides an overview of the state-of-the-art monitoring and surveillance technologies for geothermal systems used for electricity generation. The paper also includes case studies of monitoring and surveillance systems used on various geothermal applications. For instance, The Geysers power plant (U.S.A.) and Larderello power plant (Italy) will provide insights on successful monitoring and surveillance practices. The paper draws following conclusions from literature review and case studies: monitoring and surveillance technologies are essential for the effective and secure operation of geothermal system. The results can be used to develop and refine geothermal reservoir simulation models. Furthermore, these technologies are essential for early detection of corrosion processes, which are common in operating geothermal systems. Additionally, the monitoring of geothermal systems enhances the understanding on its impact on the environment, such as triggered hydraulic connectivity to shallow groundwater resources or land subsidence. Further study and development in the field of monitoring and surveillance technologies can significantly enhance the performance, dependability, and sustainability of geothermal systems. In particular, this paper introduces types of sensors and monitoring systems utilized in geothermal applications, difficulties and constraints associated with monitoring and surveillance in geothermal systems, and the possibilities for further research and development in this field.

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Wan, Ping K., Alice C. Carson e Desmond W. Chan. "Climate Change Considerations in Sustainable Development of Nuclear Power Plants in the United States". In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29331.

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Nuclear power generation has become an increasingly attractive alternative in the global power market due to growing demand for electric power, increasing global competition for fossil fuels, concern over greenhouse gas emissions and their potential impact on climate change, and the desire for energy independence. Nuclear energy plays an integral role in providing carbon free energy for sustainable development of global electric power generation. Assuring the protection of people and the environmental is a prime consideration in the design, construction, and operation of nuclear power plants. Potential environmental and safety concerns must be carefully evaluated and addressed. In order to assure that the nuclear power plant designs are sufficiently robust, the U.S. Nuclear Regulatory Commission (USNRC) requires that applicants for early site permits (ESP) and construction/operating licenses (COL) identify the most severe natural phenomena historically reported for the site and surrounding area to ensure sufficient design margin exists, considering the limited accuracy, quantity, and time in which the associated data has been collected. Because these permits are valid for a period up to 40 years, the potential impacts of climate change on the severity of natural phenomena, as it relates to the design basis and nuclear safety and environmental impacts are of increasing interest. Although no conclusive evidence or consensus of opinion is available on the long-term climatic changes resulting from human or natural causes, the USNRC has requested that climate change forecasts be considered for their potential affecting the most severe natural phenomena. The specific subject areas of concern include: • Extreme temperature and extreme precipitation (liquid & frozen) statistics – review 100 years of data around the site versus a review of the previous 30 years of data. • Extreme wind/basic wind speed – review previous 100 years of tropical cyclone data (including hurricanes) in the site vicinity versus previous 30 years of data. • Tornado – review of frequency and intensity trends and forecasts. • Drought – review of water availability / water supply during drought conditions and drought of record. • Stagnation Potential – review of conditions that would result in restrictive dispersion of greenhouse gas emissions. This paper examines the challenges and constraints in identifying and developing appropriate design- and operating-basis site/regional meteorological conditions while accounting for potential climate change during preparation of an ESP and/or COL. Because there is no regulatory guidance or quantitative acceptance criteria currently available, the methodology used to address climate change in a recent issued ESP will be discussed as an example.

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Rapporti di organizzazioni sul tema "Climatic constraints"

Burke, Marshall, e Vincent Tanutama. Climatic Constraints on Aggregate Economic Output. Cambridge, MA: National Bureau of Economic Research, aprile 2019. http://dx.doi.org/10.3386/w25779.

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Lee, Huey-Lin, Thomas Hertel, Brent Sohngen e Navin Ramankutty. Towards An Integrated Land Use Database for Assessing the Potential for Greenhouse Gas Mitigation. GTAP Technical Paper, dicembre 2005. http://dx.doi.org/10.21642/gtap.tp25.

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This paper describes the GTAP Land Use Data Base designed to support integrated assessments of the potential for greenhouse gas mitigation. It disaggregates land use by agro-ecological zone (AEZ). To do so, it draws upon global land cover data bases, as well as state-of-the-art definition of AEZs from the FAO and IIASA. Agro-ecological zoning segments a parcel of land into smaller units according to agro-ecological characteristics, including: precipitation, temperature, soil type, terrain conditions, etc. Each zone has a similar combination of constraints and potential for land use. In the GTAP-AEZ Data Base, there are 18 AEZs, covering six different lengths of growing period spread over three different climatic zones. Land using activities include crop production, livestock raising, and forestry. In so doing, this extension of the standard GTAP Data Base permits a much more refined characterization of the potential for shifting land use amongst these different activities. When combined with information on greenhouse gas emissions, this data base permits economists interested in integrated assessment of climate change to better assess the role of land use change in greenhouse gases mitigation strategies.

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Fernandes, R. Surface albedo feedback - observational constraints on climate models. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2012. http://dx.doi.org/10.4095/290188.

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Eickhout, Bas, Hans van Meijl, Andrzej Tabeau e Elke Stehfest. The Impact of Environmental and Climate Constraints on Global Food Supply. GTAP Working Paper, aprile 2008. http://dx.doi.org/10.21642/gtap.wp47.

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*Chapter 9 of the forthcoming book "Economic Analysis of Land Use in Global Climate Change Policy," edited by Thomas W. Hertel, Steven Rose, and Richard S.J. Tol The goal of this Chapter is to study the complex interaction between agriculture, economic growth and the environment, given future uncertainties. We combine economic concepts and biophysical constraints in one consistent modeling framework to be able to quantify and analyze the long-term socio-economic and environmental consequences of different scenarios. Here, we present the innovative methodology of coupling an economic and a biophysical model to combine state of the art knowledge from economic and biophysical sources. First, a comprehensive representation of the agricultural and land markets is required in the economic model. Therefore we included a land demand structure to reflect the degree of substitutability of types of land-use types and we included a land supply curve to include the process of land conversion and land abandonment. Secondly, the adapted economic model (LEITAP) is linked to the biophysical-based integrated assessment model IMAGE allowing to feed back spatially and temporarily varying land productivity to the economic framework. Thirdly, the land supply curves in the economic model are parameterized by using the heterogeneous information of land productivity from IMAGE. This link between an economic and biophysical model benefits from the strengths of both models. The economic model captures features of the global food market, including relations between world regions, whereas the bio-physical model adds geographical explicit information on crop growth within each world region. An illustrative baseline analyses shows the environmental consequences of the default baseline and a sensitivity analyses is performed with regard to the land supply curve. Results indicate that economic and environmental consequences are very dependent on whether a country is land scarce or land abundant.

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Nugent, Stevonne, e Juan Pedro Schmid. The Business Climate in Jamaica: What Does the Enterprise Survey Have to Say? Inter-American Development Bank, gennaio 2014. http://dx.doi.org/10.18235/0008436.

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Jamaican firms are constantly plagued by a number of issues that restrict their ability to grow. The World Bank's Enterprise Survey examined the key indicators to give insight on the business climate in Jamaica. Compared with firms in the Latin America and Caribbean (LAC) region, Jamaican firms face several constraints to growth and operation. Within the Caribbean Country Department (CCB), Jamaica is the only member - except Suriname - that identified close to half of the areas as constraints to firm operation. Tax rates, access to finance, practices of the informal sector, and electricity were identified as their biggest obstacles.

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Keller, David P. Quantification of “constrained” potential of ocean NETs. OceanNets, 2022. http://dx.doi.org/10.3289/oceannets_d4.1.

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This study uses an existing perturbed parameter ensemble (PPE) of simulated ocean CO2 removal (CDR) to better determine sustainable pathways of ocean-based NET deployment and to provide information to constrain the design of subsequent modelling experiments. The results show that ocean alkalinity enhancement (OAE) can only help meet SDG13 (Climate Action) when other ambitious mitigation efforts are taken. This reinforces that OAE is not a substitute for emissions reduction, but could contribute to meeting our climate goals (if other factors suggest OAE is worth doing). For SDG14 (Life Below Water), the results suggest OEA can contribute to limiting or even reversing ocean acidification. Meeting many other SDG14 objectives is closely linked to also meeting SDG13. A key recommendation is therefore, that subsequent simulations in OceanNETs should only use SDG13 compatible baseline scenarios, unless there is some specific need for process understanding at higher levels of climate change. The analysis has also determined that the idealized CDR in the PPE is not suitable for determining many socio-economic constraints and the implications that these have for meeting the SDGs. Another key recommendation is therefore, that subsequent simulations within OceanNETs should use more realistic scenarios of CDR deployment.

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Dayton, David C., Brian G. Southwell e Vikram Rao. Diversifying Energy Options in a Carbon-Constrained World. RTI Press, ottobre 2021. http://dx.doi.org/10.3768/rtipress.2021.rb.0029.2110.

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There is a critical need to reduce the static, calm the hype, and provide a realistic and complete presentation of facts to drive climate change mitigation decisions. Diversifying Energy Options in a Carbon-Constrained World is a new series to be published by RTI Press to provide a wide, cross-disciplinary discussion of carbon mitigation options and strategies to inform national and international research, scientific discussions, and policy debates.

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Kim, Son H., e James A. Edmonds. Potential for Advanced Carbon Capture and Sequestration Technologies in a Climate Constrained World. Office of Scientific and Technical Information (OSTI), febbraio 2000. http://dx.doi.org/10.2172/968483.

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Dohnert, Sylvia, Tara Lisa Persaud, Stefano Pereira, Wayne Elliott e Kayla Grant. Toward a Business Climate Reform Agenda in the Caribbean. Inter-American Development Bank, agosto 2016. http://dx.doi.org/10.18235/0007020.

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This paper is meant to help national and regional policymakers navigate the complex topic of business climate reform in the Caribbean. It combines the findings of four relatively independent data collection efforts to uncover which aspects of the current business climate most affect the private sector in that region. The analysis from the four sources indicates that the most pressing business climate constraints affecting private sector performance are: (i) an inadequately educated workforce; (ii) the cost of finance, and (iii) access to finance. These issues are discussed in detail along with others that significantly affect private sector development. The paper ends with a regional agenda and country-specific prioritized agendas for business climate reform.

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Jordon, Matthew, e Jonathan Wentworth. Woodland creation. Parliamentary Office of Science and Technology, gennaio 2021. http://dx.doi.org/10.58248/pn636.

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Large-scale woodland creation is being promoted internationally to mitigate climate change. It can also supply other benefits, such as improving biodiversity, air and water quality. This POSTnote summarises key factors influencing how much carbon is taken up by woodland, the different objectives of woodland creation, constraints to increasing UK tree cover and different finance options.

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