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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Etude du renforcement / confortement des ouvrages de protection contre les inondations et l'érosion interne / Study of the strengthening / confortement of the works of protection against the floods and the internal erosion

Elandaloussi, Radja 09 December 2015 (has links)
La construction d’un ouvrage hydraulique commence par le choix des matériaux devant le constituer. Les sols employés pour la construction d’ouvrages hydrauliques en terre peuvent être constitués de matériaux perméables tels que les sables ou les graves ou de matériaux peu perméables tels que les argiles ou les limons. En fonction de la disponibilité des matériaux à proximité du chantier, il est alors possible d’opter pour différents types d’ouvrages (ouvrages homogènes, à noyau ou zonés). Dans tous les cas, le coût d’un ouvrage tel qu’une digue est d’autant moins élevé que les sols utilisés pour sa construction sont issus de zones proches du chantier. Lorsque des sols sont disponibles en quantité suffisante à proximité du chantier mais que leur utilisation soit risquée pour la stabilité de l’ouvrage, il peut être opportun de chercher à modifier leurs caractéristiques pour qu’ils puissent être utilisés dans les mêmes conditions de sécurité que les matériaux traditionnels. C’est autour de cette problématique que ce travail de thèse a vu le jour. En particulier, ce travail vise à étudier les améliorations apportées par un traitement à la chaux appliqué sur un sol grossier soumis à un écoulement interne afin de le stabiliser contre le phénomène de l’érosion interne. La compréhension des améliorations apportées a nécessité la mise en place d’une analyse multicritère au travers d’essais dédiées. Dans la première partie de la thèse, nous nous sommes employés à développer un dispositif d’essais permettant de réaliser des essais d’érosion interne sur ce type de sol. Ce dispositif nous a permis de réaliser une étude phénoménologique sur le comportement du sol considéré, soumis à des écoulements, en fonction du sens de l’écoulement et de l’application ou pas du traitement. Par la suite une étude paramétrique a été réalisée afin de mettre en évidence l’influence des paramètres principaux : dosage de traitement, temps de cure, hauteur de l’éprouvette et surcharge. Dans une seconde partie, nous nous sommes intéressés à l’influence de l’immersion des échantillons dans l’eau sur leur stabilité. A cet effet, l’essai de dispersion, adapté à ce type de sol, a pu être utilisé et exploité. Des essais complémentaires de résistance à la compression simple ont été réalisés afin d’estimer la perte de résistance après immersion. Ce qui nous a poussés à examiner l’existence de corrélations entre les propriétés à l’érosion et les propriétés mécaniques du sol traité / The construction of a hydraulic structure starts with the selection of the materials that will constitute it. The soils used in the construction of hydraulic earthen structures may be made of permeable materials such as sands or low permeability materials such as clay or silt. Depending on the availability of materials near the site, it is possible to choose different types of structures (homogeneous structures, core or zoned). In all cases, the cost of such a structure as a dike is even lower than the soils used for its construction come from areas near the site. When soils are sufficiently available near the construction site, but their use is risky for the stability of the structure, it may be appropriate to seek to modify their characteristics so they can be used in the same security conditions than traditional materials. It is around this issue that this thesis was born. More particularly, this research aims to study the improvements made by a lime treatment on a coarse soil subjected to internal flow to stabilize against the phenomenon of internal erosion. Understanding improvements requires the establishment of a multi-criteria analysis through dedicated tests. In the first part, we are interested in developing a testing device for performing internal erosion tests on this type of soil. This device has enabled us to realize a phenomenological study of the phenomena observed with the direction of flow and the presence or not of the treatment. Subsequently a parametric study was conducted to highlight the influence of the main parameters: treatment dosage, treatment time, height of the specimen and overload. In the second part, we studied the influence of immersion samples in water for this purpose the crumb test test was adapted for this type of soil. Additional unconfined compression tests were conducted to estimate the loss of strength after immersion. This allowed us to try couplings between the properties to erosion and soil treated mechanical properties
272

The impact of climate and flooding on tree ring growth of Fraxinus pennsylvanica in north-central Texas.

Komperod, Mari 12 1900 (has links)
Tree cores of Fraxinus pennsylvanica were used in a dendrochronological analysis investigating the species' responses to climate and flooding. The objective was to develop a model that incorporates the effects of precipitation, temperature, and flooding on radial growth in this species in north-central Texas. The trees exhibited strong climatic signals. The study clearly shows that all three factors have significant impacts on tree ring growth both prior to and during growth; however, the nature and extent of these impacts are highly dependent on what time of year they occur. The large temporal variations in growth responses emphasize the importance of considering the timing of environmental events when studying tree growth responses.
273

PCH Atibaia : o contexto de reativação e a ocorrência de enchentes e inundações no município de Atibaia/SP / SHP ATIBAIA : the context of reactivation and the occurrence of floods and flooding in the municipality of Atibaia / SP

Gonçalves, Nayra de Moraes, 1986- 28 August 2018 (has links)
Orientador: Sônia Regina da Cal Seixas / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-28T11:55:10Z (GMT). No. of bitstreams: 1 Goncalves_NayradeMoraes_M.pdf: 4664706 bytes, checksum: 75132355500f0c2dc7becf74ae779895 (MD5) Previous issue date: 2015 / Resumo: O atual modelo de produção e consumo nos coloca perante uma crescente necessidade de produção de energia, sobretudo energia elétrica, e uma das principais fontes utilizadas no Brasil é a hidroeletricidade. Por outro lado, este modelo de desenvolvimento, baseado na industrialização e urbanização, gera pressão constante sobre os recursos naturais, com destaque para os recursos hídricos, o que, aliado com um planejamento urbano pouco efetivo, contribui para ocasionar impactos diversos, como enchentes e inundações. Dessa forma, esta dissertação visa a analisar o contexto em que ocorreu a tentativa de reativação da Pequena Central Hidrelétrica Atibaia, bem como as enchentes e inundações no município de Atibaia/SP. A metodologia utilizada na dissertação envolve a realização de revisão bibliográfica e a coleta de dados secundários junto a diversos órgãos governamentais e não governamentais atuantes na região; análise de relatórios; pesquisa de campo, que pode ser agrupada em três categorias: pesquisa empírica, entrevistas semiestruturadas com técnicos e especialistas envolvidos com a ocorrência de enchentes e inundações no município e aplicação de questionários à população; e, por fim, análise energética da PCH Atibaia. Com esses dados pode-se verificar que a ocorrência de enchentes e inundações deve ser atribuída a diversos fatores combinados entre si, e não a fatos isolados. Entre eles destaca-se o aumento do volume de precipitação em curto período de tempo nos meses de dezembro de 2009, janeiro de 2010 e 2011; aumento do grau de urbanização do município e, consequentemente, das áreas impermeáveis e da canalização dos recursos hídricos; ocupação de áreas de várzea e APP, entre outros. Verifica-se que o conflito sobre a reativação da PCH Atibaia teve origem em questões e interesses políticos e, pelo impacto e importância do tema e a diversidade de atores sociais envolvidos, ganhou grande destaque. Contudo, a maior parte da população ¿ tanto afetada como não afetada ¿ não possui muito conhecimento sobre o assunto, tendo sua opinião formada por questões que "ouviram falar". Apesar disso, a maioria acredita que a reativação da PCH não tenha relação com a ocorrência dos eventos de enchente e inundações no município / Abstract: he current model of production and consumption place us towards a growing need for energy production, especially electricity, and one of the main sources used in Brazil is hydroelectricity. On the other hand, this model of development based on industrialization and urbanization, creates constant pressure on natural resources, especially water resources, which, combined with ineffective urban planning, contributes to cause different impacts such as floods and flooding. Thus, this work aims to analyze the context in which the attempt to reactivate the SHP Atibaia occurred, as well as its relation with floods and flooding in the municipality of Atibaia/SP. The methodology used in the dissertation involves literature reviews and the collection of secondary data from various governmental and non-governmental agencies active in the studied region; analysis of reports; field researches, which can be grouped into three categories: empirical research, semi-structured interviews with experts and specialists involved in the occurrence of floods and flooding in Atibaia and questionnaires applied with the local population; and finally, energy analysis of the SHP Atibaia. With this data it could be verified that the occurrence of floods and flooding should be attributed to several factors combined, and not isolated facts. Among them stands out the increase in the volume of rainfall in a short period of time in the months of December 2009, January 2010 and 2011; increase in the city's urbanization level and hence an increase in impervious areas and in the channeling of water resources; occupation of lowland areas and areas of permanent preservation (APP), among others. It appears that the conflict over the reactivation of SHP Atibaia originated both on issues and political interests, and due to the impact and importance of the topic, and the diversity of actors involved, the floods events gained extreme prominence. However, the majority of the population - both affected and unaffected - does not have much knowledge about it, and they have their opinion formed by issues that "were heard". Nevertheless, most believe that the reactivation of the SHP has no relation to the occurrence of floods and flooding events in the municipality of Atibaia / Mestrado / Planejamento de Sistemas Energeticos / Mestra em Planejamento de Sistemas Energéticos
274

Metabolismo de carboidratos da espécie amazônica Senna reticulata sob cultivo em alto CO2 / Carbohydrate metabolism of the amazonian tree Senna reticulata under elevated CO2

Bruna Cersózimo Arenque 01 June 2010 (has links)
Plantas típicas de regiões alagáveis tendem a apresentar diversas estratégias morfológicas e fisiológicas a fim de otimizar as chances de sobrevivência nestes ambientes. Um dos principais mecanismos, porém menos estudados, é a plasticidade encontrada no metabolismo de carboidratos que está diretamente ligado a alta demanda energética inerente a estes locais. Senna reticulata (Leguminosae) é uma espécie pioneira típica de planícies sujeitas ao regime anual de inundação da Amazônia Central, considerada uma das mais eficientes colonizadoras destes ambientes, além de extremamente tolerante ao alagamento. Neste trabalho, pela primeira vez foram caracterizados os padrões de reserva e de mobilização de açúcares desta espécie no período que corresponde ao seu estabelecimento no início da sua primeira fase terrestre. Adicionalmente o efeito da elevada concentração de gás carbônico foi verificada cultivando-se as plantas em câmaras de topo aberto (OTCs) em concentrações de CO2 ambiente (~380 µmol) e elevado (~760 µmol). Foram realizadas coletas destrutivas para análises de conteúdo de carboidratos não estruturais ao longo de 90 dias e ao longo de 24 horas. Foi verificado que S. reticulata possui altos níveis de amido foliar indicando que essa reserva pode estar diretamente relacionada a estratégia de constante produções de novas folhas que esta espécie apresenta. As razões sacarose:monossacarídeos se apresentaram altas em todos os órgãos analisados especialmente na raiz indicando que esta espécie pode apresentar estratégias metabólicas relacionadas também a estação seca pois além da sacarose poder ser utilizada como principal substrato na formação de raízes adventícias em condições de alagamento, também pode ser útil na regulação osmótica da raiz em locais com solos que apresentam baixa disponibilidade hídrica. A elevada concentração de gás carbônico promoveu um aumento significativo das reservas de amido na folha e no caule além de diminuir a taxa de degradação de amido transitório durante o período noturno. As concentrações de açúcares solúveis (glicose, frutose e sacarose) apresentaram tendência de diminuição sob condições de atmosfera enriquecida provavelmente devido à maior utilização dos mesmos para o crescimento da raiz. Este conjunto de respostas indica que essa espécie responde de forma positiva a elevada concentração de gás carbônico utilizando-se de possíveis mecanismos que diminuem a sinalização mediada por açúcares como, por exemplo, a habilidade de aumentar a capacidade de seus drenos já existentes, promovendo a mobilização do excesso de carboidratos para reservas e crescimento. / Plants of floodplains tend to show many morphological and physiological strategies to get higher survival rates in this places. One of them but with received less attention is the plasticity showed by carbohydrate metabolism that is directly linked to high energy demand at this sites. Senna reticulata (Leguminosae) is a pioneer tree which is common in floodplains sites submitted to an annual pulse of flooding at Central Amazonian and one of the most efficient colonizers at this sites besides extremely flooding tolerant. In this work by the first time was made the characterization about reserves and mobilizations patterns of sugars on the time range that corresponding to the establishment at the initial first terrestrial phase. Additionally, the effect of high CO2 was checked by growing plants in Open-Top-Chambers (OTC´s) with ambient (~380 µmol) and elevated (~760 µmol) CO2 concentrations. It was made systematic harvests along periods of 24 hours and 90 days to determinate the carbohydrate non-structural content. It was founded that S. reticulata had higher levels of starch in leaves showing evidences that this reserve is directly linked with constantly production of new leaves strategy. The ratio sucrose:monosaccharides was high in all organs but specially in roots showing evidences that this specie has metabolic strategies also related with drought periods because besides sucrose could be used as the aim substrate to adventitious root formation at flooding conditions and can be useful too on the osmotic regulation of roots in sites with low moisture content soil. The high levels of carbon dioxide promote significative increase of starch in leaves and stem besides decrease the degradation rate of transitory starch in leaves in the dark period. The levels of soluble sugars (glucose, frutose and sucrose) showed tendency of decrease under high CO2 conditions probably due to higher use in root growth. This set of answers evidence that this tree has positively response to high CO2 useful by possible mechanisms that decrease the signaling through sugars like for example the big abiliity of increase capacity of preexistents sinks to promoting the surplus carbohydrates mobilization to reserves and growth.
275

Efficient real-time video delivery in vehicular networks

Torres Cortés, Álvaro 18 April 2016 (has links)
[EN] Vehicular Ad-hoc Networks (VANET) are a special type of networks where the nodes involved in the communication are vehicles. VANETs are created when several vehicles connect among themselves without the use of any infrastructure. In certain situations the absence of infrastructure is an advantage, but it also creates several challenges that should be overcome. One of the main problems related with the absence of infrastructure is the lack of a coordinator that can ensure a certain level of quality in order to enable the correct transmission of video and audio. Video transmission can be extremely useful in this type of networks as it can be used for videoconferencing of by traffic authorities to monitor the scene of an accident. In this thesis we focused on real time video transmission, providing solutions for both unicast and multicast environments. Specifically, we built a real-world testbed scenario and made a comparison with simulation results to validate the behavior of the simulation models. Using that testbed we implemented and improved DACME, an admission control module able to provide Quality of Service (QoS) to unicast video transmissions. DACME proved to be a valid solution to obtain a certain level of QoS in multi-hop environments. Concerning multicast video transmission, we developed and simulated several flooding schemes, focusing specifically on VANET environments. In this scope, the main contribution of this thesis is the Automatic Copies Distance Based (ACDB) flooding scheme. Thanks to the use of the perceived vehicular density, ACDB is a zeroconf scheme able to achieve good video quality in both urban and highway environments, being specially effective in highway environments. / [ES] Las redes vehiculares ad-hoc (VANET) son un tipo especial de redes en las que los nodos que participan de la comunicación son vehículos. Las VANETs se crean cuando diversos vehículos se conectan entre ellos sin el uso de ninguna infraestructura. En determinadas situaciones, la ausencia de infraestructura es una ventaja, pero también crea una gran cantidad de desafíos que se deben superar. Uno de los principales problemas relacionados con la ausencia de infraestructura, es la ausencia de un coordinador que pueda asegurar un determinado nivel de calidad, para poder asegurar la correcta transmisión de audio y vídeo. La transmisión de vídeo puede ser de extrema utilidad en este tipo de redes ya que puede ser empleada para videoconferencias o por las autoridades de tráfico para monitorizar el estado de un accidente. En esta tesis nos centramos en la transmisión de vídeo en tiempo real, proveyendo soluciones tanto para entornos unicast como multicast. En particular construimos un banco de pruebas real y comparamos los resultados obtenidos con resultados obtenidos en un entorno simulado para comprobar la fiabilidad de estos modelos. Usando el mismo banco de pruebas, implementamos y mejoramos DACME, un módulo de control de admisión capaz de proveer de calidad de servicio a transmisiones de vídeo unicast. DACME probó ser una solución válida para obtener ciertos niveles de calidad de servicio en entornos multisalto. En lo referente a la transmisión de vídeo multicast, desarrollamos y simulamos diversos esquemas de difusión diseñados específicamente para entornos VANET. En este campo, la principal contribución de esta tesis es el esquema de difusión "Automatic Copies Distance Based" (ACDB). Gracias al uso de la densidad vehicular percibida, ACDB es un esquema, que sin necesidad de configuración, permite alcanzar una buena calidad de vídeo tanto en entornos urbanos como en autopistas, siendo especialmente efectivo en este último entorno. / [CAT] Les xarxes vehiculars ad-hoc (VANET) son un tipus de xarxes especials a les que els diferents nodes que formen part d'una comunicació son vehicles. Les VANETs es formen quan diversos vehicles es connecten sense fer ús de cap infraestructura. A certes situacions l'absència d'una infraestructura suposa un avantatge, encara que també genera una gran quantitat de desafiaments que s'han de superar. U dels principals problemes relacionats amb l'absència d'infraestructura, és la manca d'un coordinador que puga garantir una correcta transmissió tant de video com d'àudio. La transmissió de video pot ser d'extrema utilitat a aquest tipus de xarxes, ja que es por emprar tant per a videoconferències com per part de les autoritats de trànsit per monitoritzar l'estat d'un accident. A aquesta tesi ens centrem en transmissió de video en temps real, proporcionant solucions tant a entorns unicast como a entorns multicast. Particularment, vam construir un banc de proves i obtinguérem resultats que comparàrem amb resultats obtinguts mitjançant simulació. D'aquesta manera validarem la fiabilitat dels resultats simulats. Fent ús del mateix banc de proves, vàrem implementar i millorar DACME, un mòdul de control d'admissió, capaç de proveir de qualitat de servici a transmissions de video unicast. DACME va provar ser una bona solució per obtindré un bon nivell de qualitat de servici en entorns de xarxes ad-hoc amb diversos salts. Si ens centrem a la transmissió de video multicast, vàrem implementar i simular diferents esquemes de difusió, específicament dissenyats per al seu ús a entorns VANET. La principal contribució d'aquesta tesi es l'esquema de difusió ACDB (Automatic Copies Distance Based). Fent ús de la densitat vehicular, ACDB es capaç d'obtindre una bona qualitat de video tant a ciutats com a vies interurbanes, sent a especialment efectiu a aquestes últimes. A més a més no es necessària cap configuració per part de l'usuari. / Torres Cortés, Á. (2016). Efficient real-time video delivery in vehicular networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62685 / TESIS
276

Assessment of flood mitigation strategies for reducing peak discharges in the Upper Cedar River watershed

Drake, Chad Walter 01 May 2014 (has links)
This thesis evaluates the effectiveness of several flood mitigation strategies for reducing peak discharges in the Upper Cedar River Watershed located in northeast Iowa. Triggered by record flooding in June 2008, the Iowa Watersheds Project was formed to evaluate and construct projects for flood reduction. The Upper Cedar was selected as a pilot watershed and a hydrologic assessment was performed to better understand its flood hydrology. Evaluation of different flood mitigation strategies was performed with HEC-HMS, a lumped parameter surface water model. The hydrologic model development is described and the model applications are analyzed. The HMS model was used in several ways to better understand the flood hydrology of the Upper Cedar River Watershed. First, the runoff potential of the basin was assessed to identify the primary runoff generation mechanisms. Areas with agricultural land use and moderately to poorly draining soils had the highest runoff potential. Following, the model was used to evaluate the impact of several flood mitigation strategies - increased infiltration through land use changes, increased infiltration through soil improvements, and added storage in the watershed to hold runoff temporarily and reduce downstream flood peaks - for different flood frequency events (the 10-, 25-, 50-, and 100-year, 24-hour design rain storms) and the June 2008 flood. Although each scenario is hypothetical and simplified, they do provide benchmarks for the types of reductions physically possible and the effectiveness of strategies relative to one another. In order to reduce the impacts of flooding in the Upper Cedar, a combination of projects that enhance infiltration and/or store excess runoff will be necessary.
277

An analysis of heavy rainfall events over the Limpopo River Basin in southern Africa, their moisture sources and pathways

Rapolaki, Ramontsheng Sakia 29 October 2020 (has links)
Severe flooding events in subtropical southern Africa are not uncommon and can cause damage to infrastructure, lead to huge economic losses, and fatalities. Although extreme rainfall events can have far-reaching negative consequences, they can also provide large amounts of freshwater within a short time span, which supports the rain-fed farming upon which much of the population depends. However, the mechanisms through which extreme rainfall is produced in southern Africa are still not well understood. In particular, relatively little is known about where the moisture, a key ingredient in the rainfall, is sourced and how it is transported into the region. This thesis aims to address some of the gaps in this understanding by examining the moisture sources and subsequent moisture transport moisture into one of the key river basins in southern Africa, the Limpopo River Basin (LRB). The LRB, located in eastern southern Africa and spanning four countries, has experienced a number of extreme flooding events over the last three decades. Using CHIRPS satellite merged rainfall data for 1981-2016, the thesis identified the top 200 heavy extreme rainfall events in the LRB and the associated weather systems. It was found that tropicalextratropical cloud bands account for almost half of the events and tropical lows are responsible for just over a quarter. The remaining quarter of the events are associated with mesoscale convective systems and cut-off lows, the latter more important during transition seasons. Most of the events occur in the late summer when tropical lows and cloud bands are more common. Some relationships between the frequency of heavy rainfall events over the LRB and interannual climate modes of variability such as ENSO, SIOD, and SAM were found. Having examined the annual cycle of the top 200 heavy rainfall events, the analysis then applied the Lagrangian trajectory model HYSPLIT, with NCEP II reanalysis data as input, to backtrack air parcels from the LRB to their moisture source on seasonal scales and in terms of the types of weather systems involved. The resulting trajectories show that the seasonal transport of moisture over the LRB originates from seven moisture source regions; namely, local continental, tropical southeast Atlantic Ocean, midlatitude South Atlantic Ocean, tropical Northwest Indian Ocean, tropical southwest Indian Ocean, subtropical southwest Indian Ocean, and the Agulhas Current. Important differences in moisture source regions and pathways exist between early (OctoberDecember) and late (January-April) summers, with the tropical northwestern Indian Ocean and the northern Agulhas Current sources more prominent during JFMA than OND. Generally, moisture v source regions and transport pathways for LRB tend to be influenced by both the regional summer season circulation and the synoptic systems involved. Thus, it was found that cloud band and tropical low events within the top 200 tend to have the Congo Basin as an important moisture source whereas this source is less evident for cut-off low events. To help assess the robustness of the composite synoptic approach, the final part of the thesis applied the Lagrangian analysis to the most severe case in the top 200 events over the LRB (11- 21 January 2013). It was found that this case was largely linked to three main moisture sources: (1) tropical northwest Indian Ocean, (2) the Agulhas Current / Mozambique Channel, subtropical Southwest Indian Ocean, and (3) continental sources over the Congo Basin and northern Tanzania. Generally, the moisture source regions and pathways for the January 2013 event agreed with the climatological moisture source regions over the LRB, apart from the obvious absence of the tropical southeast Atlantic source in this case. In general, the thesis has provided a better understanding of the characteristics of heavy rainfall events over the LRB in terms of their associated weather systems, seasonality, interannual variability, and moisture source regions and trajectories.
278

Les capacités adaptatives des communautés de la périphérie de Dakar face aux inondations / The adaptive capacities of communities on the periphery of Dakar in the face of floods

Diop, Moustapha Sokhna 07 October 2019 (has links)
Depuis le début des années 2000, les quartiers de la périphérie de Dakar et notamment le Département de Pikine, constitué largement d’ensembles urbains informels, subissent des inondations à chaque saison des pluies. Les processus qui ont conduit à cette situation sont plutôt bien connus et associent le manque d’anticipation, les constructions en zone non ædificandi, intervenues en période sèche et l’arrêt de l’exploitation de l’aquifère sous-jacent, entre autres.Devant le manque d’empressement des pouvoirs publics pour apporter un soulagement aux populations inondées, vivant déjà dans la pauvreté et l’insalubrité, une vaste mobilisation d’organisations civiques est intervenue et tente d’apporter des solutions, parfois dans l’urgence, mais aussi de manière plus durable. C’est justement dans cette mobilisation que nous avons d’abord recherché la constitution de capacités adaptatives, que nous pourrions attribuer aux différentes communautés, vivant dans les quartiers inondés.Nous nous sommes d’abord intéressés aux propositions, issues de la littérature sur le changement climatique, pour nous rendre compte que de tels cadres analytiques statiques, ne pouvaient rendre compte, ni de la diversité d’actions mises en œuvre, ni de leur évolution dans le temps. L’enquête ethnographique et l’observation participante auprès des organisations civiques agissant sur le terrain, durant cinq ans environ, nous a permis de collecter les narratifs, articulant motifs, actions, valeurs et autres éléments culturels, ainsi que des savoirs de l’expérience, voire de constater leur évolution dans le temps.En nous appuyant sur la théorie des pratiques de Pierre Bourdieu, avec des éléments comme le capital social ou culturel, pas comme des concepts fermés, préétablis, mais tels qu’ils ressortaient du corpus de l’enquête de terrain (par exemple : entraide, contrôle social informel, inclusivité et gouvernance, en lien avec chaque organisation…), nous avons ainsi produit un cadre sociologique dynamique, rendant compte des observations empiriques et présentant des boucles de renforcement.Notre constat sur l’existence de « stocks » de capital social, limité à sa composante intra-communautaire, nous a incité à mettre en place un espace de discussion, d’échanges et de partage des expériences, dans le but de générer des synergies et permettant l’élargissement du capital social. Ceci a rencontré de nombreuses résistances, révélant un climat de méfiance, attribuée, selon les dires des participants, aux pratiques manipulatrices, tant d’organisations extérieures que des pouvoirs publics. En outre, nous avons pu montrer qu’à partir des caractéristiques ou discours des organisations, que certaines, dirigées par des notables et dépendantes du statu quo des équilibres de pouvoir, pouvaient être qualifiées de conservatrices, alors que d’autres (la minorité), plus portées vers l’innovation sociale, questionnaient ce statut quo, générant des controverses et des échanges houleux lors des réunions.Si l’action spontanée des communautés, visant à se prémunir des conséquences d’événements climatiques, est réelle et effective, elle participe aussi du processus de l’adaptation aux changements perçus, pas seulement de manière réactive, mais aussi comme recherche d’un mieux vivre. De même, l’expérience dans l’action, renforce les savoirs de l’expérience et pourrait contribuer à la résilience, mais toujours tronquée, tant que ce rôle n’est pas reconnu par les pouvoirs publics. / Since the beginning of the 2000s, the districts in the suburban of Dakar, particularly the sector of Pikine, which is largely made up of informal habitations, have been flooded every rainy season. The processes that led to this situation are rather well known and combine the lack of anticipation, construction in non-extended area, occurred in dry periods and the cessation of exploitation of the groundwater, among others.Facing the lack of the authorities to provide solution to the flooded populations, already living in poverty and insalubrity, a large mobilization of civic organizations has intervened and tries to provide solutions, sometimes in the emergency, but also in a more sustainable way. It is precisely in this mobilization that we first sought the constitution of adaptive capacities, that we could attribute to the different communities, living in the flooded districts.We first looked at the proposals from the literature on climate change to realize that such static analytical frameworks could not account for either the diversity of actions implemented or their evolution in time. The ethnographic survey and participant observation with civic organizations acting in the field, over approximately during five (5) years, allowed us to collect narratives, articulating motives, actions, values and other cultural elements, as well as knowledge of the experience, or even to see how they change over time.Based on Pierre Bourdieu's theory of practice, with elements such as social capital or cultural capital, not as closed pre-established concepts, but as they emerged from the corpus of the field survey (eg. mutual support, informal social control, inclusivity and governance, in connection with each organization ...), we have thus produced a dynamic sociological framework, accounting for empirical observations and presenting reinforcement loops.Our observation on the existence of "stocks" of social capital, limited to its intra-community component, has prompted us to set up a space for discussion, exchange and sharing of experiences, with the aim of generating synergies and allowing the expansion of social capital. This has met with a great deal of resistance, revealing a climate of mistrust attributed, according to the participants, to manipulative practices by both outside organizations and public authorities. In addition, we have shown that from the characteristics or discourse of organizations, that some, led by notables and dependent on the status quo of the balance of power, could be qualified as conservative, while others (the minority), more inclined towards social innovation, questioned this status quo, generating controversy and heated exchanges during meetings.If the spontaneous action of the communities, aimed at protecting themselves from the consequences of climatic events, is real and effective, it also participates in the process of adaptation to perceived changes, not only reactively, but also as a search for a better life. Similarly, experience in action strengthens the knowledge of the experience and could contribute to resilience, but still truncated, as long as this role is not recognized by the public authorities.
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Suitable areas for cultivation of protein-rich crops in Sweden : An GIS-based study on 7 protein-rich crops

Cardegård, Fanny January 2020 (has links)
Conditions are predicted to become more favorable for protein-rich crops in Northern Europe, which bring opportunities for cultivation of protein-rich crops in Sweden. This study assessed the current suitability for cultivation of protein-rich crops in Sweden based on biophysical conditions. This study defined suitability indicators with suitability conditions for each crop regarding (i) soil texture, (ii) soil pH value, (iii) vegetation period length, (iv) and soil temperatures were created, and overlayed to create suitable areas for protein-rich crops. Suitable areas and distributions were found for: common bean, faba bean, field pea, lentil, narrow-leafed lupin, quinoa, and soybean. A present and future risk analysis with wet and dry periods was carried out to find suitable areas for the crops under the risk of wet and dry periods. The study found that Sweden have the possibility to cultivate protein-rich crops to a greater extent which is shown by the distribution of suitable areas for protein-rich crop. Quinoa was found suitable to be cultivated in nearly all arable land in Sweden. In the future, there is an increase in suitable areas for protein-rich crops that are not exposed to drought. A decrease was seen in suitable areas for protein-rich crops that are not exposed to flooding.
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Understanding housing co-operatives' flood risk reduction behavior : Perceptions of risk, coping, and incentives

Zetterlund, Angelica January 2021 (has links)
Escalating global warming-induced cloudbursts and intense precipitations are already causing an increase of material damages in Sweden. Flooding is therefore one of the main focus pointsin Sweden’s national strategy for climate adaptation. Studies of climate adaptation in the built environment and among private property owners are however lacking in Sweden, compared to the public sector and new construction. Housing co-operatives are a private property owner important to understand since this form of ownership currently are growing exponentially in Sweden, and co-operatives are predicted to not be engaged in flood risk reduction work. While individual homeowners have previously been studied, housing co-operatives have only been studied once in this field, and there are therefore large knowledge gaps. This study consists of a qualitative interview study of seven Swedish Riksbyggen housing co-operatives.This study shows that as information surrounding flooding and adaptation was not communicated to co-operatives, housing co-operatives’ adaptation, as well as their awareness and perceptions of various factors, and perceptions of risk, coping, and incentives, is largely based on risk experience. Moreover, due to this lack of information, the interviewed chairpersons’ perceptions of risk, coping, and incentives are found low. More targeted support and communication related to climate adaptation is identified as needed. Risk perceptionappeared to increase with more local risk information, and especially the social consequences should be highlighted. The perceived coping and incentives for proactive adaptation wouldlikely increase with more awareness of easier and cheaper measures which generates other financial and social benefits.

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