The PhD is concerned with the construction of site knowledge and how this is transformed into knowing where and how to intervene in a river system close to ecological collapse. It involves three overlapping topics: • Site knowledge and its impact upon the design process • Development of tools and techniques appropriate for working on a particular type of site condition: the threshold between land and water • Transitory: the impact of dynamic processes and events on inhabitation Site knowledge emerges from a process of investigating a location. It is generated by on-site and off-site operations. This involves the architect in a dynamic set of relationships - between encounters on the ground in the here and now, with more remote encounters with the site from the studio and archive. This mode of site study amplifies the impact of scale shift and it exposes the variable and provisional status of a location, while also providing a way of operating in environments that can be considered dynamic. The PhD is premised upon the need for a work to relate to its surrounding environment. The hinged meaning between the terms a site and to site have relevance to the design process. A site, as a noun, suggests a specific place, such as a plot of land, whereas the verb to site, suggests that a work will be placed in relation to other things. Site knowledge is thus generated through the act of describing a place, through the act of making drawings and other descriptions of that place. It generates ways of conceptualising a site and leads to action: knowing how and where to intervene in a location. The River Murray provided a context for the project work of the PhD. Research led to tools for recording (on site) and interpreting (off site) the impacts of flood events on the settlements on the riverbanks that were protected by levees that worked against the natural forces of the system. The research culminated in a range of designs that demonstrated how to integrate town and tourist developments into the re-established cyclical flows necessary for the health of the system.

Thesis (M.Env.Dev.) - University of KwaZulu-Natal, Pietermaritzburg, 2007. / Full text also available online. Scroll down for electronic link.

Thesis (M.S.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (January 11, 2007) Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2005. / Includes bibliographical references (p. 65-66).

This study combined flood-frequency analysis, 1-D (one-dimensional) hydraulic modeling using HEC-RAS, and flood-loss modeling using FEMA's Hazus-MH (Hazards U.S. Multi-Hazard) in order to: 1) quantify how different flood-frequency methodologies affect flood-risk assessments, and 2) quantify the impacts of different floodplain-management scenarios along the Middle Mississippi River (MMR). The nine scenarios tested here included various combinations of flood-frequency methodology, buyouts, and levee configurations. The levee configurations analyzed included: 1) current levee configuration, 2) no levees, 3) a 1500 m levee setback, 4) a 1000 m levee setback, and 5) a customized levee setback designed to maximize protection around existing infrastructure. Two study reaches were chosen: (1) an Urban Study Reach within St. Clair and northern Monroe Counties, IL, with levees designed to withstand the 500-year flood and (2) an Agricultural Study Reach within Union and Jackson Counties, IL, with <100-year levees. A flood-frequency analysis was completed for the St. Louis, MO gauging station, and detailed building inventories were used to estimate flood losses on a structure-by-structure basis (Hazus-MH UDF analysis) for an array of floods ranging from the 2- to the 500-year events. These flood-loss estimates were combined with a stochastic levee-failure model. Finally, estimated flood damages from Hazus-MH were integrated across the full range of flood recurrences in order to calculate expected annual damage (EAD). This study's flood-frequency analysis and corresponding flood-loss assessment demonstrate how differences in flood-frequency methodology can significantly impact flood-risk assessments. EAD based on the UMRSFFS (Upper Mississippi River System Flow Frequency Study) flood frequencies was 68% ($45.4 million) lower than EAD based on this study's flood frequencies. This decrease in EAD demonstrates that the UMRSFFS flood frequencies and corresponding stages may significantly underestimate flood risk within the Urban Study Reach. The 100-year discharge in the UMRSFFS appears to be underestimated by an estimated 17% (187,000 cfs), resulting in a 10% (1.6 m) underestimation of the 100-year flood level. Given the magnitude of the EAD, discharge, and stage differences documented here, a reanalysis of the MMR flood frequencies, flood profiles, and flood maps should be considered. The hydraulic modeling completed here showed that levee setbacks and levee removal successfully reduce stages for all recurrence intervals. For the 100-year flood, average reductions ranged from 0.20 m for a 1000 m levee setback to 1.61 m with levees removed. In general, stage reductions increased with increasing discharge and with increasing setback distance. The flood-level reductions are attributed to increased floodwater storage and conveyance across the reconnected floodplain. Compared to the current conditions, the levee setback and levee removal scenarios tested here reduced flood losses for large, infrequent flooding events but increased flood losses for smaller, more frequent flood events. When combined with buyouts of unprotected structures, levee setbacks reduced flood losses for all recurrence intervals. The 1000 m and 1500 m levee setbacks required buyouts in order to reduce EAD; however, a levee setback carefully planned around existing high-value structures reduced EAD with or without buyouts. The planned levee setback configuration combined with buyouts resulted in the largest decreases in EAD: a $16.8 million (55%) decrease in the Urban Study Reach and an $8.3 million (93%) decrease in the Agricultural Study Reach. Overall, this project showed that levee setbacks in combination with buyouts are an economically viable approach for flood-risk reduction along the study reaches and likely elsewhere where levees are widely employed for flood control. Designing a levee setback around existing high-value infrastructure can maximize the benefit of the setback while simultaneously minimizing the costs. Potentially, this type of planned levee configuration could be used as a template for the replacement of aging or failing levee systems.

xv, 203 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Water and pumice accumulated behind a dam that, upon failure, scoured the c1aydominated floodplain and deposited pumice sands across the Sycan Valley. The pumice originated from the eruption of Mount Mazama (approximately 7660 ybp), and dam failure occurred very shortly afterwards. In response to the flood the lower Sycan River underwent episodes of channel aggradation and degradation. This study presents the history of channel evolution for the lower Sycan River from 11,000 years ago to present, based on floodplain stratigraphy and radiocarbon chronology. Seven primary periods of channel and floodplain development are identified: I. Early Holocene Dynamic Equilibrium; II: Sycan Outburst Flood; III. Initial Channel Formation; IV. Degradation & Widening; V. Aggradation & Lateral Migration; VI. (Secondary) Degradation & Widening; VII. Modern Dynamic Equilibrium. The active floodplain of the modern lower Sycan River is flanked by terraces of the rapidly abandoned Sycan Outburst Flood deposits. / Committee in Charge: Dr. Patricia McDowell, Chair; Dr. Jim E. O'Connor; Dr. Andrew Marcus

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No. of bitstreams: 1 Dissertação - Sandra Helena da Silva.pdf: 4647522 bytes, checksum: 91bfa027a6c85076bfdefc5ae806ef9d (MD5) Previous issue date: 2015-10-16 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / To understand the strategies for conservation the Valha-me-Deus and Chaves Islands, both located at Juruti/PA, was the mais objective of this study. For that, there were made analysis about the environmental sistem of the islands, in their eco-bio-socio-cultural aspects. The concepts of autopoiese, organization, sustainability and adaptability were the theorical references to comprehend the strategic actions of autopoiese’s conservation from cultivators women at local agroecosystems. The research followed the study of multiple cases’ model, epistemologically based on the dialetic paradigm of the systemic complexity. There were used informal interviews, with previous script and stories of life. Beyond the systemic observation about the environmental system of the Islands, from March 2013 to May 2015. The transcript data indicated limitations to preserve the autopiese at the studied Islands, both to the human beings and the environmental backgrounds, as the fauna and the flora. Among the limitations are the most recent climate changes, that generates extreme floods at the varzeas, affecting the productive units. The fragilities found at the public agricultural and social politics leave the farmers at their own luck, showing the capital move to mobilizate the larbor force, in the search of financial conditions at the cities, introdution of large animals, the water buffaloes at the Valha-me-Deus Island, resulting in big environmental loses. The data indicates losses and ressignification in the way of life, with new archetypes, rules and doctrines imposed by the State and the Church, reflecting at the familiar relations, losing its culturals collections that were rebuilt over generations. As resistance strategy to the maintenance of their productive units, the cultivators have been trying to develop several activities, that generates monetary income, featuring the pluri-activity, specially at the Valha-me-Deus Island. The autopoiese’s conservation of the cultivators from the Island are kept, between the states of order and disorder unleashed by the economic, social and environmental interferences, promoting steadily a cultural reconstruction. In that, some knowledge of themselves and of the environmental system are lost, endangering the Islands sustainability. / Compreender as estratégias para a conservação, nas Ilhas do Valha-me-Deus e Chaves, ambas localizadas no município de Juruti/PA, foi o objetivo central desse estudo. Para tanto, foram realizadas análises sobre o sistema ambiental das Ilhas, em seus aspectos eco-bio-sócio-culturais. Os conceitos de autopoiese, organização, sustentabilidade, adaptabilidade foram às referências teóricas para compreensão das ações estratégicas de conservação da autopoiese de mulheres cultivadoras nos agroecossistemas locais. A pesquisa seguiu o modelo de estudo de caso múltiplos, tendo como base epistemológica o paradigma dialético da complexidade sistêmica. Foram utilizadas entrevistas informais, com roteiro prévio e histórias de vida. Além da observação sistemática sobre o sistema ambiental das Ilhas, durante março de 2013 a maio de 2015. Os dados transcritos indicaram limitações para a conservação da autopoiese no ambiente das Ilhas pesquisadas, tanto para os seres humanos, quanto nas formações ambientais, como a fauna e flora. Entre as limitações estão às próprias mudanças climáticas mais recentes, gerando inundações extremas, nas várzeas afetando as unidades produtivas. As fragilidades nas políticas públicas agrícolas e sociais deixam os agricultores a própria sorte, indicando o movimento do capital na mobilização da força de trabalho, na busca de condições financeiras nas cidades; introdução de animais de grande porte, os bubalinos na Ilha do Valha-me-Deus, gerando perdas ambientais. Os dados indicaram perdas e ressignificações no modo de vida, com novos arquétipos, regras e doutrinas impostas pelo Estado e a Igreja, repercutindo nas relações familiares, com perdas dos acervos culturais reconstruídos ao longo das gerações. Como estratégias de resistência na manutenção de suas unidades produtivas, as cultivadoras têm buscado desenvolver atividades diversas, geradoras de renda monetária, caracterizando a pluriatividade, em especial na Ilha do Valha-me-Deus. A conservação da autopoiese das cultivadoras das Ilhas mantém-se, entre os estados de ordem e desordem desencadeados pelas interferências econômicas, sociais e ambientais, promovendo continuamente uma reconstrução cultural. Nessa, há perdas de saberes sobre si mesmo e sobre o sistema ambiental vivenciado, colocando em risco a sustentabilidade nas Ilhas.

The global climate is changing and much of this is attributed to the greenhouse effect, which has been exacerbated by increased anthropogenic releases of greenhouse gases (GHGs). However, important GHGs, carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4), are produced naturally in the soil during the metabolism of many soil microbial and plant communities. The generation rate of GHGs depends on many factors, including soil community composition, nutrient availability, temperature, and soil moisture. Predicted climate variability is expected to alter temperature and rainfall patterns, which can impact the factors regulating natural generation of GHGs. With changing fluxes of GHGs, the natural feedback loops between GHG generation and climate may change. Increased emissions from natural sources would exacerbate climate change, whereas decreased emissions may mitigate its impacts. Floodplains may be particularly susceptible to climate change, as their biogeochemical processing is driven by hydrology. For this study, ten mesocosms were installed on the floodplain of Stroubles Creek in southwest Virginia. A flood event was simulated in half of these mesocosms in both early spring and mid-summer, which represent extremes in soil moisture and primary productivity on the floodplain. Headspace gases were monitored for CO, N2O, and CH4. Efflux of CO2 and N2O was higher in summer than spring, and also increased following wetting events. Methane production was greater in the spring, with no detectable change with wetting. Increases in summer rainfall events could increase the release of important GHGs to the atmosphere, potentially at levels significant to climate change. / Master of Science

No description available.

The annual hydrological cycle of floodplains supports fishes that are uniquely adapted to optimize resources throughout the year. Such adaptations to changing environments include air-breathing for seasonally hypoxic waters and directed movements to best utilize habitats as they become available. This study examined the environmental, temporal and body-size influences on air-breathing behavior and movement ecology of Arapaima sp., one of the most economically and ecologically significant species in the Amazon. Acoustic (n=15) and radio (n=12) telemetry was used to study the influences on air-breathing and movement ecology of arapaima in the Central Amazon. Generalized additive mixed models showed that temperature was the most influential predictor of air-breathing intervals, followed by body size. The shortest breathing intervals were associated with consecutive "aggressive" breaths while the longest breathing intervals had consecutive "calm" breaths. Generalized linear mixed models showed that flood stage was the most important predictor of residency time, directional movement, and rate of movement. Fish moved faster in the flood and dry stages than the rising and falling stages, and spent longer in one place in the rising and falling stages than the flood and dry stages. Findings of this study may be used to inform management decisions for arapaima conservation, such as protected habitat and population counts, with applications to fishes across river-floodplain ecosystems globally. / Master of Science