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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.
321

Application of a GIS Multi-Criteria Decision Analysis for the Identification of Intrinsic Suitable Sites in Costa Rica for the Application of Managed Aquifer Recharge (MAR) through Spreading Methods.

Bonilla Valverde, José Pablo, Blank , Clemens, Roidt, Mario, Schneider, Lisa, Catalin, Stefan 27 March 2017 (has links) (PDF)
Costa Rica’s annual mean precipitation is above 3300 mm, but this precipitation is not evenly distributed in time or space, producing clear differentiated wet and dry seasons in most of the country. Droughts are also common phenomena which greatly affect the availability of water resources. Managed aquifer recharge (MAR) schemes are being taken into consideration to enhance the underground water storage capacity of the country. The present study constitutes the first assessment for the identification of suitable sites for the implementation of MAR technology spreading methods (SM) in Costa Rica. The suitable sites are identified by means of a geographic information system multi-criteria decision analysis (GIS-MCDA) based on four criteria: hydrogeological aptitude, terrain slope, top soil texture and drainage network density. Four steps are performed in order to identify these sites: problem definition, screening for suitable areas, suitability mapping, and sensitivity analysis. The suitability map was divided in two zones after the screening: suitable and unsuitable, the first zone was further divided in five classes according to the weighted linear combination (WLC) ranking. The results indicate that 61% of the country is suitable for conducting SM. This map is a tool for future implementation of MAR techniques in the country.
322

La participation des pêcheurs artisanaux à la gestion des activités halieutiques artisanales tropicales : étude de cas dans le Golfo Dulce, Costa Rica. / The participation of small scale fishers in the management of tropical coastal marine resources. : case study of Golfo Dulce, Costa Rica

Fargier, Luc 21 June 2012 (has links)
La participation des pêcheurs artisanaux a longtemps été écartée de la gestion institutionnelle des activités halieutiques marines côtières dans la zone intertropicale, notamment au sein des États centralisés d’Amérique Centrale. L’objectif majeur de cette thèse était de déterminer le potentiel de cogestion des activités halieutiques artisanales au sein du Golfo Dulce (Pacifique Sud du Costa Rica). La réflexion s’organise en deux parties. La première est consacrée à l’étude de la gestion des activités halieutiques artisanales exploitant les ressources marines côtières, ressources communes, dans les pays en développement tropicaux, et la seconde, à une étude de cas du Golfo Dulce. Dans un premier temps, le secteur halieutique artisanal costaricain a été caractérisé, notamment au travers de son évolution historique et de sa gestion déconcentrée et pluri-institutionnelle. Les différentes modalités de participation des pêcheurs artisanaux à la gestion de leurs activités halieutiques sont illustrées par plusieurs études de cas (Cahuita, Marino-Ballena, Palito, Tárcoles, Golfo Dulce). Dans un second temps, les pratiques de pêche et le profil socio-économique des pêcheurs artisanaux des trois communautés de Bahía Pavones (sud-est du Golfo Dulce) ont été caractérisés. L’activité de pêche artisanale y repose sur huit espèces, dont les deux principales, Lutjanus gutattus (vivaneau rose) et L. peru (vivaneau garance) seraient surexploitées. La participation des pêcheurs artisanaux aux organisations locales est importante malgré un déficit de confiance envers ces dernières. Enfin, la comparaison des différentes études de cas a mis en évidence l’existence de huit conditions nécessaires au développement d’un processus de cogestion d’activités halieutiques artisanales au Costa Rica. Au sein de l’Aire Marine de Pêche Responsable du Golfo Dulce, malgré la volonté des pêcheurs artisanaux de participer à une pêche durable, c’est la manipulation de ces derniers par divers acteurs qui entrave le processus de cogestion. / The participation of small scale fishers in institutional management of tropical coastal marine fisheries activities has long been excluded, notably in the centralized states of Central America. The major objective of this study was to determine the potential of co-management of coastal marine small scale fisheries activities in Golfo Dulce (South Pacific of Costa Rica). The study consists of two main parts. The first analyses the management of small scale fishing activities exploiting coastal marine resources in tropical developing countries, and the second is devoted to the case study of Golfo Dulce. In a first step, the Costa Rican small scale fishery sector was characterized, especially its historical evolution and its decentralized and multi-agency management. The various modalities of the participation of small scale fishers in its management were illustrated by several case studies (Cahuita, Marino-Ballena, Palito, Tárcoles, Golfo Dulce). Second, fishing practices and socio-economic profile of small scale fishers of the three communities of Bahía Pavones (southeast of Golfo Dulce) were characterized. The small scale fishing activity is essentially based on eight species, of which the two main ones, Lutjanus gutattus (spotted rose snapper) and L. peru (Pacific red snapper) could be overexploited. The participation of small scale fishers to local organizations is significant despite a general lack of confidence towards these organizations. Finally, comparing the different case studies revealed the existence of eight key conditions for the development of a successful co-managed small scale fishery in Costa Rica. Within the Marine Responsible Fishing Area of the Golfo Dulce, it is the manipulation of small scale fishers by various user groups (in particular government and the tourism sector) that hinders the process of co-management.
323

Einfluss von Klima und Topographie auf Struktur, Zusammensetzung und Dynamik eines tropischen Wolkenwaldes in Monteverde, Costa Rica / The Effect of Climate and Topography on Structure, Composition and Dynamics of a Tropical Cloud Forest in Monteverde, Costa Rica

Häger, Achim 27 April 2006 (has links)
No description available.
324

Étude comparative de la protection internationale des minorités en Europe et en Amérique / Comparative study of the international protection of minorities in Europe and in America

Simon, Sophie 02 March 2015 (has links)
Les minorités sont les fruits de l’histoire, des conquêtes, des défaites, des modifications de frontières. Mais si aucune histoire nationale ne ressemble à une autre, les minorités, dans leur diversité, se trouvent dans des situations s’apparentent les unes aux autres. Dans ce contexte global, cette étude a pour objectif d’appréhender dans quelle mesure les droits nationaux et internationaux des minorités répondent effectivement aux besoins des personnes appartenant à ces dernières. Pour ce faire, deux thématiques revenant régulièrement dans les doléances des membres des minorités ont été sélectionnées. Il s’agit, en premier lieu, de la prise en compte des spécificités relatives à l’habitat (dans sa diversité) et, en second lieu, de la possibilité de communiquer dans sa propre langue. Après une présentation du droit international portant sur ces questions, est ici étudiée la façon dont ce droit ou plutôt ces droits sont transposés et mis en œuvre dans les systèmes nationaux (en effet, il existe de fortes variantes entre la protection offerte par les organes universels et celles offertes par les organes régionaux européens et américains). Pour rendre compte de la diversité des situations nationales, six pays sont ici étudiés. Il s’agit de l’Espagne, de la France et de la Lituanie pour l’Europe et du Canada, du Costa Rica et du Paraguay pour l’Amérique. Nous constatons que, feignant de méconnaître l’intérêt que présente une protection convenable des minorités pour la stabilité de leur société nationale et même pour la démocratie en général, les gouvernants ne sont pas toujours prêts à mettre en œuvre les dispositions visant à protéger les personnes appartenant à des minorités et opposent l’intérêt général ou des arguments tirés du caractère unitaire de leur peuple, de leur territoire ou de leur nation. A ceci s’ajoutent des difficultés pratiques lors de la mise en œuvre des normes adoptées, difficultés occasionnées par des raisons financières, par exemple le coût des mesures positives visant à l’égalité effective dans les domaines de l’enseignement, des médias, de la vie privée et familiale ou encore obligation de partage des bénéfices générés par l’extraction minière avec les peuples autochtones. D’autres raisons peuvent être liées à l’intolérance sous-jacente dans la population majoritaire, par exemple les attaques de campements Roms ou l’interdiction de parler une langue minoritaire dans certains contextes ou lieux. Malgré cela, le droit international des minorités est en évolution continue, puisant dans la diversité des contextes régionaux et se fondant tant sur les droits de l’homme et le droit à ne pas être discriminé, que sur une transposition à toutes les minorités d’éléments des droits reconnus aux peuples autochtones en tant que premiers habitants d’un territoire donné. De plus, dans une volonté de promouvoir une démocratie véritable à caractère participatif, les organes de droits de l’homme poussent les autorités nationales à associer toujours plus les membres des minorités aux prises de décision les concernant, et à prendre ainsi en compte les besoins de ces derniers. Ainsi, l’étude comparée de la protection des minorités en Europe et en Amérique permet de se rendre compte des difficultés pratiques empêchant de protéger effectivement les minorités et d’appréhender dans quelle mesure le droit international peut aider les États à surmonter ces difficultés. / Minorities are the product of history, conquests, defeats and border changes. No two national histories are alike, however, minorities, in their diversity, find themselves in situations that appear similar the one another. In this overall context, the objective of this research is to better understand to what extent national and international minority rights effectively meet the needs of individuals belonging to those minorities. To do so, two issues that reoccure in the grievances of members of minorities have been selected for study. These are firstly the consideration shown towards housing specificities (in their diversity) and secondly, the possibility of communicating in one’s own language. Following the presentation of international law related to these issues, is studied the way this law, or better said these laws, are transposed and implemented in the national systems (in fact, there are major variants between the protection offered by universal organs and the one offered by European and American regional organs). In order to take into consideration the diversity of national situations, six countries were selected for this study. These were Spain, France and Lithuania in the European context, and Canada, Costa Rica and Paraguay in the American context. Our findings show that those who govern pretend to be unaware of the benefits related to adequate protection of minorities for the stability of national societies, as well as for democracy at large. As such, they are not always ready to implement the provisions that aim to protect persons belonging to minorities and claim the interest of the public good or arguments based on the unity of their people, territory or nation as reasons for doing so. In addition, it should be mentioned that some practical difficulties exist in the implementation of adopted norms. These include difficulties caused by financial reasons, for example, the cost of positive measures aiming at effective equality in the field of education, media, private and family life or the obligation to share with indigenous people the benefits generated by mining. Other reasons may be linked to underlying intolerance present in the majority population, for example, attacks on Roma settlements or prohibition on speaking a minority language in some spheres or places. However, the international rights of minorities are constantly evolving, drawing on the diversity of regional contexts and based on human rights and the right not to be discriminated against, as well as on the application, to all minorities, of elements of the rights recognized to indigenous peoples as the first inhabitants of a given territory. Moreover, in an effort to promote genuine democracy of a participatory nature, human rights bodies push national authorities to involve ever more members of minorities in decisions that affect them, thereby taking their needs into consideration. The comparative study of the protection of minorities in Europe and in America enables reporting the practical difficulties preventing minorities from being effectively protected and assists in understanding to what extent international law can help countries overcome these difficulties.
325

Application of a GIS Multi-Criteria Decision Analysis for the Identification of Intrinsic Suitable Sites in Costa Rica for the Application of Managed Aquifer Recharge (MAR) through Spreading Methods.

Bonilla Valverde, José Pablo, Blank, Clemens, Roidt, Mario, Schneider, Lisa, Catalin, Stefan 27 March 2017 (has links)
Costa Rica’s annual mean precipitation is above 3300 mm, but this precipitation is not evenly distributed in time or space, producing clear differentiated wet and dry seasons in most of the country. Droughts are also common phenomena which greatly affect the availability of water resources. Managed aquifer recharge (MAR) schemes are being taken into consideration to enhance the underground water storage capacity of the country. The present study constitutes the first assessment for the identification of suitable sites for the implementation of MAR technology spreading methods (SM) in Costa Rica. The suitable sites are identified by means of a geographic information system multi-criteria decision analysis (GIS-MCDA) based on four criteria: hydrogeological aptitude, terrain slope, top soil texture and drainage network density. Four steps are performed in order to identify these sites: problem definition, screening for suitable areas, suitability mapping, and sensitivity analysis. The suitability map was divided in two zones after the screening: suitable and unsuitable, the first zone was further divided in five classes according to the weighted linear combination (WLC) ranking. The results indicate that 61% of the country is suitable for conducting SM. This map is a tool for future implementation of MAR techniques in the country.
326

Avaliação e calibração de extratores de fósforo em três diferentes ordens de solo da Costa Rica / Evaluation and calibration of soil phosphorus extractants in 3 different soil orders from Costa Rica

Corrales, Roger Armando Fallas 14 February 2013 (has links)
Diferentes metodologias de determinação de fósforo no solo (P total, Bray 1, Mehlich 1, Mehlich 3, Olsen modificado, Resina de troca iônica, H3A-1 modificado e H3A-2 modificado) foram avaliadas e calibradas para seu uso em três distintas ordens de solos (Andisols, Inceptisols e Ultisols) coletados em diferentes lugares da Costa Rica. Aos resultados das análises de P e às outras variáveis químicas dos solos foram aplicadas análises de correlação, nas quais resaltam o teor de Ca, Mg e Al como fatores relacionados ao P recuperado pelos diferentes extratores. Entre os resultados destacam as calibrações de uma modificação nas metodologias H3A-1 e H3A-2 com a resposta das plantas de arroz, metodologias que tinham sido testadas unicamente contra os resultados de outros extratores. Ao nível geral as metodologias Olsen modificada e à resina de troca iônica apresentaram-se como os extratores mais adequados quando não se faz distinção por tipo de solo ou ordem, mas foram encontradas diferenças no comportamento dos diferentes métodos de extração segundo o tipo de solo, podendo variar a conveniência de utilizar um método ou outro. Em geral as metodologias P total, Bray 1 e Mehlich 1 foram as que representaram em menor medida a resposta das plantas de arroz à condição de P nos solos do experimento de calibração. As metodologias de avaliação de P apresentaram correlação entre si, apresentando também variações se avaliadas para uma condição geral (todos os solos) ou diferenciando por ordens. / Different soil phosphorus extraction methodologies (total phosphorus, Bray 1, Mehlich 1, Mehlich 3, modified Olsen, ion exchange resin, modified H3A-1 and modified H3A-2) were assessed and calibrated to evaluate its suitability to determinate the plant available phosphorus in different Costa Rican soils (Andisols, Inceptisols and Ultisols). The phosphorus results of these analyses were correlated against other soil chemical characteristics like pH, Ca, Mg and Al, in order to determinate which of these characteristics are related to the soil phosphorus content determined by the different extractants, were founded correlations of P with Al, Ca and Mg. As a results are presented for the first time the calibrations of the methodologies H3A-1 and H3A-2 (a modification) against phosphorus plant absorption and relative plant yield. In general conditions (all the soil orders) the modified Olsen method and the ion exchange resin method, resulted in better correlations with plant responses, therefore its seems to be the more suitable methods in this conditions. The analysis of the data by soil order, demonstrate some differences among extractants, that suggest the selective use of the methodologies and interpretation of results in accordance with soil order. In general total P, Bray 1 and Mehlich 1 were the less reliable methods to represent the rice plants response to the condition of soil phosphorus in this greenhouse calibration. Some of the assessed phosphorus methodologies present correlation among themselves, in both conditions (all soil orders in a group, or fractionated by soil order).
327

Avaliação e calibração de extratores de fósforo em três diferentes ordens de solo da Costa Rica / Evaluation and calibration of soil phosphorus extractants in 3 different soil orders from Costa Rica

Roger Armando Fallas Corrales 14 February 2013 (has links)
Diferentes metodologias de determinação de fósforo no solo (P total, Bray 1, Mehlich 1, Mehlich 3, Olsen modificado, Resina de troca iônica, H3A-1 modificado e H3A-2 modificado) foram avaliadas e calibradas para seu uso em três distintas ordens de solos (Andisols, Inceptisols e Ultisols) coletados em diferentes lugares da Costa Rica. Aos resultados das análises de P e às outras variáveis químicas dos solos foram aplicadas análises de correlação, nas quais resaltam o teor de Ca, Mg e Al como fatores relacionados ao P recuperado pelos diferentes extratores. Entre os resultados destacam as calibrações de uma modificação nas metodologias H3A-1 e H3A-2 com a resposta das plantas de arroz, metodologias que tinham sido testadas unicamente contra os resultados de outros extratores. Ao nível geral as metodologias Olsen modificada e à resina de troca iônica apresentaram-se como os extratores mais adequados quando não se faz distinção por tipo de solo ou ordem, mas foram encontradas diferenças no comportamento dos diferentes métodos de extração segundo o tipo de solo, podendo variar a conveniência de utilizar um método ou outro. Em geral as metodologias P total, Bray 1 e Mehlich 1 foram as que representaram em menor medida a resposta das plantas de arroz à condição de P nos solos do experimento de calibração. As metodologias de avaliação de P apresentaram correlação entre si, apresentando também variações se avaliadas para uma condição geral (todos os solos) ou diferenciando por ordens. / Different soil phosphorus extraction methodologies (total phosphorus, Bray 1, Mehlich 1, Mehlich 3, modified Olsen, ion exchange resin, modified H3A-1 and modified H3A-2) were assessed and calibrated to evaluate its suitability to determinate the plant available phosphorus in different Costa Rican soils (Andisols, Inceptisols and Ultisols). The phosphorus results of these analyses were correlated against other soil chemical characteristics like pH, Ca, Mg and Al, in order to determinate which of these characteristics are related to the soil phosphorus content determined by the different extractants, were founded correlations of P with Al, Ca and Mg. As a results are presented for the first time the calibrations of the methodologies H3A-1 and H3A-2 (a modification) against phosphorus plant absorption and relative plant yield. In general conditions (all the soil orders) the modified Olsen method and the ion exchange resin method, resulted in better correlations with plant responses, therefore its seems to be the more suitable methods in this conditions. The analysis of the data by soil order, demonstrate some differences among extractants, that suggest the selective use of the methodologies and interpretation of results in accordance with soil order. In general total P, Bray 1 and Mehlich 1 were the less reliable methods to represent the rice plants response to the condition of soil phosphorus in this greenhouse calibration. Some of the assessed phosphorus methodologies present correlation among themselves, in both conditions (all soil orders in a group, or fractionated by soil order).
328

Scale-dependent management of biodiversity and ecosystem processes in fragmented landscapes

Kormann, Urs Gabriel 20 October 2014 (has links)
No description available.
329

Intraspecific Trait Plasticity in Coffee Agroforestry Systems of Costa Rica

Gagliardi, Stephanie 18 March 2014 (has links)
Although a common plant response to environmental gradients, leaf trait plasticity is often uncharted in agroforestry systems. The objective of this study was to examine the effect of a i) local-scale gradient (light, nutrients) induced by shade tree diversity and ii) large-scale gradient (climato-edaphic) induced by altitude on coffee plant response on multiple agroforestry research farms in Costa Rica. Results show large variability of coffee traits: leaf photosynthetic rates, specific leaf area (SLA) and number of fruiting nodes deviate along both gradients. Mean SLA increased with increasing shade tree diversity. However, with increasing altitude, full sun coffee photosynthesized at higher rates than shaded coffee. Concurrently, other coffee leaf physiological and morphological traits differentiated between full sun and shaded coffee with increasing altitude. Results suggest soil moisture and light availability dominate environmental correlates to intraspecific coffee trait plasticity, providing insight to sources of coffee performance variability in monoculture and agroforestry systems.
330

Intraspecific Trait Plasticity in Coffee Agroforestry Systems of Costa Rica

Gagliardi, Stephanie 18 March 2014 (has links)
Although a common plant response to environmental gradients, leaf trait plasticity is often uncharted in agroforestry systems. The objective of this study was to examine the effect of a i) local-scale gradient (light, nutrients) induced by shade tree diversity and ii) large-scale gradient (climato-edaphic) induced by altitude on coffee plant response on multiple agroforestry research farms in Costa Rica. Results show large variability of coffee traits: leaf photosynthetic rates, specific leaf area (SLA) and number of fruiting nodes deviate along both gradients. Mean SLA increased with increasing shade tree diversity. However, with increasing altitude, full sun coffee photosynthesized at higher rates than shaded coffee. Concurrently, other coffee leaf physiological and morphological traits differentiated between full sun and shaded coffee with increasing altitude. Results suggest soil moisture and light availability dominate environmental correlates to intraspecific coffee trait plasticity, providing insight to sources of coffee performance variability in monoculture and agroforestry systems.

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