Avec une population croissante et des ressources en eau de surface limitées, l'hydrogéologie des îles Galápagos reste pour une grande part inconnue. Les précipitations sont relativement faibles et inégalement réparties dans le temps et l'espace. Le centre économique de l'archipel, l'île de Santa Cruz, ne dispose que de quelques cours d'eau intermittents tandis que l'île de San Cristóbal présente plusieurs rivières pérennes. Dans le cadre de ce travail, une approche pluridisciplinaire est utilisée afin de caractériser l'hydrogéologie de l'Archipel. Une nouvelle technique d'interprétation des sondages életro\-magné\-tiques héliportés a été développée. Grâce à des méthodes géostat\-istiques, elle permet la construction d'une grille 3D de la résistivité électrique. Les données issues de la mission SkyTEM réalisée sur les îles de Santa Cruz et San Cristóbal en 2006 sont mises en perspectives. Confrontée aux observations de surface collectées par télédétection et sur le terrain, la géophysique permet de proposer un modèle conceptuel pour l'île de San Cristóbal. Les conditions climatiques ont été suivies avec la mise en place de stations météorologiques le long du versant au vent de l'île de Santa Cruz. La présence de brouillard pendant 6 mois de l'année représente un apport supplémentaire pour la recharge des aquifères. Cet apport a été quantifié avec une méthode basée sur un modèle d'interception à base physique. L'aquifère de base de l'île de Santa Cruz a été étudié avec la propagation du signal de marée, des essais de pompage, et la cartographie de la fracturation. Ces travaux montrent que les basaltes ''jeunes'' fracturés ont une forte perméabilité. En revanche, les failles n'ont qu'un effet limité sur l'hydrogéologie régionale, car elles sont peu connectées. Les configurations hydrologiques contrastées au sein de l'archipel sont expliquées par un schéma d'évolution. Dans les îles relativement jeunes, telles que Santa Cruz, les basaltes fracturés sont perméables. Ils offrent peu de résistance à l'intrusion saline et l'eau douce est rapidement drainée jusqu'à la mer. Les conditions sont plus favorables dans les îles plus âgées. Les perméabilités plus faibles et l'incision des vallées permettent l'émergence de sources.

Thesis: Ph. D., Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2019 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 131-137). / The Galápagos Cold Pool (GCP) is a region of anomalously cold sea surface temperature (SST) just west of the Galápagos Archipelago. Modeling studies have shown that the GCP is maintained by wind- and current-driven upwelling. The Galápagos Archipelago lies on the equator, in the path of the Pacific Equatorial Undercurrent (EUC) as it flows eastward across the Pacific at the depth of the thermocline. It is hypothesized that the EUC upwells into the GCP as it reaches the topographical barrier of the Galápagos Archipelago. The path of the EUC in the vicinity of the archipelago is not well understood. The 'Repeat Observations by Gliders in the Equatorial Region' (ROGER) program deployed a fleet of Spray autonomous underwater gliders in the region just west of the Galápagos Archipelago from 2013 - 2016 with the goal of continuously occupying three transects that form a closed area, with the archipelago as the eastern boundary. / Gliders obtained subsurface measurements of temperature, salinity, and velocity with unprecedented temporal and spatial resolution. These measurements are used to observe the path of the EUC as it bifurcates into a north and south branch around the Galápagos Archipelago. Net horizontal transport into the volume defined by the closed area formed by the glider transects is used to estimate an average vertical velocity profile in the region of the GCP, indicating upwelling in the upper 300 m. The bifurcation latitude of the EUC, estimated to be approximately 0.4°S from volume transport as a function of salinity, is coincident with the meridional center of the archipelago, suggesting the bifurcation latitude is topographically controlled. Ertel potential vorticity and a Bernoulli function are qualitatively conserved, supporting an inertial model of the EUC. / Average spectral variance from Argo profiling float observations is used to show that tropical instability waves propagate with frequency and wavelength consistent with linearized, equatorial [beta]-plane model results and may impact the GCP, according to their vertical structure. / by Julie K. Jakoboski. / Ph. D. / Ph.D. Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution)

Les concepts de durabilité (ou développement durable) et de la conservation de la biodiversité visent à la protection des écosystèmes naturels. Bien que les deux concepts soient intrinsèquement liés, les différences pratiques concernant leur conceptualisation et leur mise en ouvre amènent le risque de divergence entre les objectifs de conservation et de la durabilité. Ceci est lié à la compréhension multidimensionnelle du concept de développement durable et aux approches bio-centriques de la conservation, qui ont eu tendance à déconnecter les systèmes humains des systèmes naturels, au lieu de considérer ces premiers comme une partie intégrante des systèmes naturels. Pour surmonter ces défis, il faut comprendre les liens entre les systèmes sociaux et les systèmes écologiques. Cependant, ces liens sont complexes et interagissent à différents niveaux. Simultanément, des processus de gouvernance interagissent à plusieurs à plusieurs échelles (du niveau local au niveau global). La compréhension de ces liens nécessite l'échange et la production de connaissances cohérentes et actionnables; connaissances qui sont idéalement pertinentes dans toutes les disciplines scientifiques, ainsi que pour la société. De cette façon des solutions pratiques, contribuant à la réalisation de la transition vers la durabilité et de la conservation de la biodiversité, peuvent être développées. Par conséquent, des approches inter- et transdisciplinaires sont nécessaires pour produire et combiner les différents types de connaissances, notamment pour combler l’écart entre les connaissances souvent déconnectées générées par les sciences naturelles et sociales. Dans cette thèse, nous adoptons donc une approche inter- et transdisciplinaire afin d’étudier la conservation de la biodiversité et la durabilité des systèmes socio- écologiques. Cette thèse s’appuie sur trois études de cas empiriques effectuées pour étudier les problèmes de conservation et de développement durable dans les îles Galapagos. Ce faisant, nous avons utilisé trois différentes méthodologies participatives (Delphi-Q-PRA) qui synthétisent ou génèrent des connaissances à partir d'une grande variété d'acteurs de la société des Galápagos. Ainsi, dans le Chapitre 3, nous avons d'abord caractérisé les interrelations dynamiques générales et les relations causales du système socio-écologique des Galapagos, qui génère des impacts environnementaux, ainsi que les réponses sous la forme d'action politique et de gestion qui sont nécessaires pour atténuer ces impacts. Dans le Chapitre 4, nous avons par la suite exploré des discours de conservation pour expliquer une série de questions de conservation en identifiant les conflits, les valeurs et les relations de pouvoir et la façon dont ces discours sont liés à différentes approches de gouvernance de la conservation et des conflits de conservation (impliquant d'autres espèces). Dans le Chapitre 5, nous caractérisons un conflit pratique et émergent centré sur les tortues géantes (Chelonoidis spp.) et les agriculteurs dans la zone rurale de l'île de Santa Cruz. Dans ce chapitre, nous évaluons la relation entre plusieurs variables sociales et écologiques étroitement liées, et nous étudions comment ces variables peuvent être utilisées pour améliorer les stratégies de conservation et de durabilité. Dans la discussion générale du Chapitre 6, nous offrons une analyse des différentes perspectives de ce travail en expliquant l'utilité du processus transdisciplinaire et participatif pour co-créer des connaissances, définir les problèmes spécifiques du système et pour trouver de nouvelles solutions afin de pouvoir aider les décideurs politiques dans les transitions vers la durabilité et de la conservation de la biodiversité. Par ailleurs, nous incluons également une analyse approfondie et une comparaison croisée des résultats entre les méthodes utilisées, et comment le transfert de connaissances a été réalisé par la transdisciplinarité et la participation. Enfin, nous offrons une analyse des perspectives de ce travail et comment elles peuvent être utilisées dans d'autres contextes et servir à opérationnaliser d’autres cadres de conservation et de la politique de développement durable internationaux.Enfin dans le Chapitre 7, nous tirons quelques conclusions qui se réfèrent à: i) La pertinence de la recherche pour la formation de consensus pour intégrer les connaissances dans des situations complexes dans les milieux de conservation complexes et où les conflits d'éléments de preuve sont communs. ii) L'importance de l'analyse de discours pour comprendre la relation homme-environnement (présente et passée) afin d'aborder les futurs défis de la conservation et de la durabilité. De même, la pertinence de l'analyse de discours dans les systèmes socio-écologiques pour capturer et exposer les différentes relations de pouvoir. Dans le but que les règles spécifiques pour la conservation et de la durabilité sont perçues comme étant justes et légitimes par tous les acteurs qui sont impliqués dans le processus. iii) L'utilisation significative d'une approche transdisciplinaire et participative pour impliquer divers acteurs dans la caractérisation et la solution des enjeux de la conservation afin de permettre d'intégrer les connaissances et d’augmenter la confiance interpersonnelle et interinstitutionnelle entre les partis. De nouvelles approches scientifiques qui combinent les connaissances locales, la science et les politiques pour produire des résultats appropriées, persistants et durables sont urgents pour atteindre une transition adéquate vers la durabilité et à la conservation de la biodiversité qui en fait partie. Ce travail est une contribution pour combler l'écart entre les différentes sciences naturelles et sociales, les méthodes, la science et les processus politiques, et les scientifiques et la société en général. / Sustainability and biodiversity conservation aim at the protection and maintenance of natural ecosystems. Although both are inherently related concepts, practical differences in their conceptualization and implementation carry the risk of discrepancies between conservation and sustainability objectives. This is related to the multi-dimensional understanding of the sustainability concept and the bio-centric approaches to conservation that have tended to disconnect human systems instead of considering these as an integral part of natural systems. Overcoming these challenges requires the understanding of the linkages between the social and ecological systems. However, these linkages are complex and interact at different interconnected levels from social to ecological and government processes which are at the same time interacting at several scales, ranging from local to global. Understanding these linkages requires the exchange and generation of cohesive and actionable knowledge that is relevant across scientific disciplines, as well as for society, so that practical solutions contribute to the transition towards sustainability and biodiversity conservation. Consequently, inter and transdisciplinary approaches are required to yield and aggregate knowledge, in particular to bridge the gap between the often-disconnected insights generated by natural and social sciences.I therefore consider it adequate to have a transdisciplinary approach to study biodiversity conservation and the sustainability of social ecological systems. This thesis builds on three empirical case studies to study conservation and sustainability challenges on the Galapagos Islands. In doing so, I used three different participatory methodologies (Delphi-Q-PRA) that either synthesised and/or generated knowledge from a wide variety of Galapagos societal actors. Thus, in Chapter 3, we first characterised the general dynamic inter-linkages and causal relationships of the Galapagos social-ecological system that generates environmental impacts and the responses in the form of policy and management actions that are required to mitigate these impacts.In Chapter 4 we subsequently focused on exploring conservation discourses to explain a range of conservation issues by identifying conflicts, values, and relations of power and how these discourses are related to different conservation governance approaches and conflicts with other species. In Chapter 5, we characterise a practical and emergent conservation conflict between giant tortoises (Chelonoidis spp.) and farmers in the rural area of Santa Cruz Island. In this chapter we assess the relationship of several social and ecological inter-linked variables and how these can be used to improve conservation and sustainability strategies.In the general discussion in Chapter 6, I provide an analysis of the different insights of this work by explaining the usefulness of transdisciplinary and participatory processes to co-create knowledge, to delineate the specific system problems and to further find novel solutions to aid policy and decision makers in the transitions towards sustainability and biodiversity conservation. Furthermore, I include a thorough analysis and cross-comparison of the results between the used methodologies, and how transfer of knowledge was achieved through transdisciplinarity and participation. Lastly, I provide an analysis of the insights of this work and how they can be used in other contexts and to operationalize other international conservation and sustainability policy frameworks. In Chapter 7, I provide a series of conclusions that refer to: i) the relevance of consensus building to integrate knowledge in complex conservation settings and where conflicts of evidence are common, ii) the importance of discourse analysis to understand the past and current human-nature relationships to address future conservation and sustainability challenges. Similarly, the relevance of discourse analysis in social-ecological systems to capture and expose different relations of power so that specific conservation and sustainability rules are perceived as fair and legitimate by all the actors that are involved in process. iii) The significant use of a transdisciplinary and participatory approach to involve varied stakeholders in conservation issues, to integrate knowledge and to increase interpersonal and inter-institutional trust between stakeholders where conservation conflicts occur. New scientific approaches that combine local knowledge, science and policies to produce adequate, persisting and sustainable results are urgent to achieve an adequate transition to sustainability and biodiversity conservation as part thereof. This work is a contribution to bridge the gap between different natural and social sciences, methods, science and policies, and scientists and society in general. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Small isolated populations are of particular conservation interest due to their increased extinction risk. This dissertation investigates two small wild bird populations using genetic approaches to inform their conservation. Specifically, one case study investigated a Greater Sage-grouse (Centrocercus urophasianus) population located in northwest Wyoming near Jackson Hole and Grand Teton National Park. Microsatellite data showed that the Jackson sage-grouse population possessed significantly reduced levels of neutral genetic diversity and was isolated from other Wyoming populations. Analysis with single nucleotide polymorphisms (SNPs) and microsatellite data provided further evidence that the population's timing of isolation was relatively recent and most likely due to recent anthropogenic habitat changes. Conservation recommendations include maintaining or increasing the population's current size and reestablishing gene flow with the nearest large population. The second case study investigated the genetic distinctiveness of the Floreana island population of the Galápagos Short-eared Owl (Asio flammeus galapagoensis). Mitochondrial DNA sequence data did not detect differences across nine island populations, yet microsatellite and morphometric data indicated that limited gene flow existed with the population and surrounding island populations, which appeared asymmetric in direction from Floreana to Santa Cruz with no indication of gene flow into Floreana. These results have important conservation implications and recommend that the Floreana Short-eared Owl population be held in captivity during the rodenticide application planned for an ecosystem restoration project in 2018. The population is less likely to receive immigrants from surrounding island populations if negatively effected by feeding on poisoned rodents.

In this collection of papers I have summarized my investigations into the field of evolutionary genetics and more specifically into patterns of biodiversity and evolutionary processes. The lizards (and frogs) studied here share common features in that they are largely present in unique environments, which are also regions that are biologically understudied. Most of these taxa show high degrees of endemism, interesting natural history characteristics, and each group manifests distinctive adaptations of general evolutionary interest. My work in the genus Telmatobius has been a progressive approach that began in my MS program, and it first focused on alpha taxonomy, morphological variation, and species boundaries. This work led to new studies initiated and completed at BYU involving further taxonomic revision (Formas et al., 2003; Chapter 1), and then revisiting and re-evaluating species boundaries established earlier (with allozyme markers) and this time with population level molecular (mitochondrial DNA) markers (Chapter 2). Our results indicate that the striking differences in size, coloration and general appearance in the various Lake Titicaca morphotypes are not genetically based. Further, there is evidence that these morphotypes have evolved very rapidly after demographic bottlenecks eroded present genetic variability. Telmatobius frogs of Lake Titicaca are listed by the International (IUCN) as critically endangered. We support this classification and further suggest studies to explore open questions like the possibility of adaptation along ecological resource gradients. Lizards of the genus Microlophus are interesting but for different reasons, and studies of this group constitutes the bulk of my dissertation work. The genus includes both Galapagos insular species, and continental taxa distributed in a linear gradient along > 4000 km of the western coast of South America. In studying Microlophus I first tackled the unresolved phylogenetic relationships within the genus (Chapter 3) and then pay attention to phylogeographic aspects of the most speciose lizard radiation in the Galapagos Archipelago (Chapter 4). Chapter 3 is a single manuscript provisionally accepted in the journal Systematic Biology. This paper introduces the lizard genus Microlophus (“lava lizards”) as a study system, and includes a large nuclear data set accompanied by an equally large mitochondrial data set (7877 characters in total). This paper explicitly differentiates among sequence alignments of gene regions that vary in tempo and class of mutational events. We show that this recognition is important and we suggest ways to appropriately deal with the alignment of multi-locus non-coding DNA data sets. A secondary finding in this study is that mtDNA and nDNA topologies are discordant with each other but that both are strongly supported, and that the nuclear topology is concordant with species distribution patterns along coastal South America. We hypothesize that in this particular region of the tree, the nuclear genome recovers a topology that is closer to the species tree, and conflicts occur due to likely secondary contact of distantly related taxa, suggesting that unique taxonomic relationships in the mtDNA gene tree are the result of hybridization. This last point highlights the value of dense taxonomic and character sampling for teasing apart different aspects of evolutionary processes. Chapter 4 is a manuscript to be submitted to the journal Evolution; in this study we further investigate the most speciose radiation of Microlophus in the Galapagos, based on an unparalleled sampling of most islands and small islets in the Archipelago. We use mtDNA sequences to both test hypothesized between-island colonization routes, as well as the expectation that within-island phylogeographic structure should be greater on older islands. Our mtDNA gene tree is strongly supported and allows rejection of previous alternatives, and we propose a novel sequence of between-island colonization events. Our results also reject the idea of phylogeographic structure been related solely to island age. Instead, we provide evidence to suggest that active volcanism as a major player in the generation of genetic diversity in within-island environments, and this is further compounded by the seemingly stochastic nature of within-island long-distance colonization routes mediated by ocean currents. We suggest that the direction and intensity of these currents, as currently understood, are insufficient to generate a priori hypotheses of oceanic colonization routes and their influence on gene flow. We do show that the standard stepping-stone model of migration, where genetic interchange is only possible among neighboring localities, does not explain much of the within-island population genetic structure unraveled by this study. From a biological conservation perspective the study of patterns of recent evolutionary history in the Galapagos provides with a window to evolutionary processes that have shaped and continue to impact the generation of biodiversity in the Galapagos Archipelago. Islands have long been viewed as natural laboratories of evolutionary change, and thus all island isolates are or could be distinctly important components of the larger, archipelago-wide processes. We provide working hypotheses for some of the demographic processes that might be generating within- and between-island biodiversity in this clade of lizards; confirmation of these explanations with independent data will have management implications for conserving the unique patterns observed in the Galapagos biota, but also the processes that generated these patterns.

Title from title page of PDF (University of Missouri--St. Louis, viewed March 9, 2010). Includes bibliographical references.

Thesis (Ph.D.)--University of Delaware, 2005. / Principal faculty advisor: J.A. Leo Lemay, Dept. of English. Includes bibliographical references.

The demand for complex structures and the urge to perform more detailed structural analyses in an early stage of the project design phase has increased the use of parametric design in the construction sector, especially among architects and structural engineers. Also, an increasing demand for sustainable structures is creating pressure on engineers and architects to design optimized structures that consume as little resources as possible. Keeping these demands in mind, this thesis tries to uncover the benefits of parametric design and optimization by applying these processes to industrial roof truss structures.The primary objective of the thesis is to investigate the feasibility and reliability of parametric design and optimization processes in real-life designs. For this purpose, a parametric algorithm has been developed in the visual programming software Grasshopper 3D. The workflow performs structural analysis and design verification on a parametric FE-model using the FEA software for parametric engineering, Karamba 3D in combination with Python where standards for design verification were scripted. These procedures were developed to be applied on both steel and timber truss structures. The workflow then performs a constrained cross-sectional and geometrical optimization of the truss structures. For the optimization process, the plug-in Galapagos have been used which uses evolutionary and simulated annealing techniques.After analyses of different cases and on comparison of the results from the model response verification, the resulting models showed that the workflow and analysis procedure was capable of obtaining a solution that is more effective and as reliable as the traditional structural analysis procedures and thus can be used for real case. When used during preliminary design, the parametric design procedure displayed great potential in saving time, thus saving resources and cost which paves a promising path for implementations in this sector.

No description available.

Espaces emblématiques des dynamiques complexes entre l’homme et l’écosystème dans des aires protégées abritant des ressources naturelles commune, les îles Galápagos et le Yasuní en Équateur partagent une histoire de dégradation environnementale, conflits socio-environnementaux et chaos territorial. La présence de biens communs, source d’une rente économique liée à la biodiversité et aux hydrocarbures (Yasuní) attire depuis un demi-siècle les intérêts des industriels du pétrole et du tourisme qui ont systématiquement exercé un poids déterminant sur les décisions en matière d’aménagement et de gestion de ces espaces, influant également sur leur gouvernance. Cette réalité joue à l’encontre de politiques d’aménagement territorial pour les deux espaces, Réserves de la Biosphère de l’UNESCO, depuis des décennies. Les Galápagos et le Yasuní témoignent en même temps de la manière dont les gouvernements équatoriens ont eu recours à une « instrumentation » des politiques pour décider le sort des deux aires protégées. Cette thèse montre comment un problème structurel – l’absence d’une politique d’aménagement territorial – a facilité la mobilisation d’instruments de politique pour administrer les deux réserves naturelles. L’histoire du Yasuní est un exemple éloquent de cette pratique d’instrumentation de politiques. La création du parc en 1979, puis les modifications de ses limites et le découpage de la Réserve de la Biosphère Yasuní, dont le parc est le noyau, ont été tous réalisés par des instruments de politiques. De même, aux Galápagos la puissance publique a opéré ses choix en matière d’accès aux espaces protégés et d’utilisation de leurs ressources, en privilégiant les instruments de politique. La loi spéciale des Galápagos (LOREG) a de facto gouverné l’archipel depuis son entrée en vigueur en 1998. Dans les deux cas, l’absence d’une politique d’aménagement territorial a permis l’adoption de décisions top-down sur l’administration des deux espaces.La «révolution citoyenne» du président Correa, en dépit d’une profonde refonte institutionnelle et d’un nouveau paradigme de développement – le Buen Vivir, ou Sumak Kawsay – ne saura changer la manière d’aménager les espaces des deux aires protégées. La planification est élevée à politique d’État qui prime sur toute autre politique, mais dans cette vision l’aménagement du territoire devient un instrument au service de la planification étatique.Ce travail, conduit dans une perspective interdisciplinaire en utilisant une grille de lecture encore peu explorée (les instruments de politique publique) veut aussi contribuer à de nouvelles pistes de réflexion sur l’action publique en matière d’aménagement du territoire ainsi que sur la gouvernance d’aires protégées riches en ressources naturelles communes. / Archetypes of the complex interactions between humans and ecosystems in protected areas rich in Common Pool Resources (CPR), the Galapagos Islands and the Yasuní in Ecuador share a history of environment degradation, socio-environmental conflicts and chaotic land development. The abundance of CPR, source of a lucrative rent from biodiversity and crude (in the Yasuní case) have attracted the interests of oil and tourism businesses over the last fifty years. These industries have consistently steered public decisions over the creation, spatial organisation and administration of these natural reserves, additionally affecting their governance, a reality which has hindered the implementation of land-use planning policies for these areas which are two UNESCO MAB Reserves. The Galapagos and Yasuní protected areas are also a powerful example of the peculiar way whereby Ecuador governments over the last five decades have “instrumented” policy making, preferring the use of policy tools to public policies to decide on the two areas’ fate. This thesis shows how a structural problem such as the absence of a land use planning policy, has thrust the practice of policy tools adoption, instead of policy making, to manage the two protected areas. The “revolución ciudadana” led by president Correa succeeded in re-founding State institutions and launching a new development paradigm (Sumak Kawsay or Buen Vivir) however, it did not advance on land-use management related issues particularly regarding the two areas. Correa has placed national planning at the heart of public policy making it the state policy – backed by a powerful bureaucratic structure – but in this process, land use planning is considered as an instrument in support of national planning. This research, carried out under an interdisciplinary perspective, using policy tools as analytical key, wishes to contribute new insights and methods of analysis on public land use planning and management, as well as governance of common pool resources in protected areas.