The problem of correlating unit hydrograph features to topographic and man-made basin characteristics received attention in this report. The unit graph features considered herein were the peak discharge and the time lag of basin response. In order to facilitate the desired regression analysis, the two-parameter gamma model proposed by Edson was utilized in the investigation. The parameters of the model were obtained by the simultaneous solution of the equations for unit graph peak and lag using observed unit hydrographs for 16 basins in the Piedmont region of North Carolina and 14 basins located in Northern Virginia. In the opinion of many, these parameters are a better measure of the complex relationship which exists between the runoff from a basin and the topographic features of that basin than are the values of the unit graph peak and lag time themselves. The basin characteristics utilized in the investigation were: basin area, length of the longest streamcourse in the basin, average stream slope between points 10 percent and 85 percent downstream of the headwaters, and the percent of the impervious area contained in the basin. This last factor served as a measure of the amount of urban development present in the watershed. The investigation was hampered by a regrettable lack of sufficient data to derive regression equations of good reliability. This fact was due to the reduction of the data into groups by narrow geographical ranges. Thus, the number of stations available for analysis in anyone group was insufficient for purposes of a reliable regression analysis. From the investigation, it appears that the most significant basin characteristics affecting runoff are length, slope, and urban development. The strongest regression equations were derived using those three characteristics. It appears that the length and slope factors give better results when combined in the form (L/√S). / Master of Science

Deep water formation in the Labrador Sea, a marginal sea within the subpolar region of the North Atlantic Ocean, is vitally important to the ventilation of the global ocean interior with atmospheric gases including oxygen (O₂) and carbon dioxide (CO₂). To better understand the current mechanisms of ocean ventilation, and improve predictions of future deoxygenation and anthropogenic carbon uptake, the complex relationships between physical processes, chemical properties, and biological activity must be unraveled. Ocean biogeochemical models (OBMs) can offer a more complete picture of the ocean state than the limited snapshots provided by observations. The overarching goal of this dissertation is to use a data-constrained OBM to examine the processes controlling O₂ and CO₂ variability in the central Labrador Sea. In Chapter 2, I present the optimization of a data-assimilative regional OBM which simulates the physical and biogeochemical state of the North Atlantic Ocean from 2002 to 2017. The optimization process includes (1) removing the model spin-up to initialize the biogeochemical simulation from GLODAPv2.2016b 1° × 1° and other climatological estimates, (2) adjusting parameterized phytoplankton quantum efficiency, and (3) using a Green’s Functions approach to tune OBM parameters against O(105) in-situ biogeochemical measurements collected by BGC-Argo floats and research hydrography. I find significant model-data misfit reduction in the subpolar North Atlantic which demonstrably improve Labrador Sea modeled O₂, surface ocean pCO₂, and chlorophyll-a against independent satellite data and observation-based products. Using this data-constrained model, I then investigate the seasonal and interannual variability of central Labrador O₂ and surface ocean pCO₂. The high-frequency SeaCycler mooring dataset provides unique insight into the convective region of the central Labrador Sea over 2016. I use SeaCycler data to better understand the model simulation and, in turn, use the model to expand these biogeochemical insights in space and time. In Chapter 3, I present an oxygen budget of the central Labrador Sea over 2016–2017 by decomposing modeled dissolved O2 into its advective transport, diffusive transport, biological, and air-sea flux terms. We find that the competing effects of air-sea exchange and diffusive mixing are so balanced that there is minimal O₂ storage in the upper 150 m. In Chapter 4, I examine modeled and observation-based estimates of surface pCO₂ against in-situ SeaCycler data. Our analysis examines the seasonal and interannual variability of pCO₂ and reveals key biases in the non-thermal component of pCO₂, which is the dominant driver of modeled and estimated surface pCO₂ variability in the central Labrador Sea. Across all chapters, my dissertation works to bridge ongoing modeling and observational efforts to expand our understanding of ocean biogeochemical processes.

La caractéristique la plus évidente de l’interface terrestre est son hétérogénéité. Phénoménologiquement, celle-ci, anthropique ou naturelle, transparaît de limites qui définissent les formes déployées dans l’espace géographique. Ces limites sont certes dues à une dynamique temporelle, tout autant que à une dynamique scalaire. Celle-ci se manifeste dans les rapports possibles et changeant existant entre échelles dans la mesure où tout échelle ne peut se concevoir que comme relative à une autre servant de référence. Ceci conduit à la relativité d’échelle (R.E.) qui devrait permettre de définir intrinsèquement l’espace géographique. Le premier objectif est de montrer la possibilité d’utiliser la R.E. en géographie. Au coeur de la R.E., on trouve la géométrie fractale qui reste indispensable pour essayer de comprendre l’organisation scalaire du monde. Jusqu’à présent les fractales n’étaient utilisées que comme un outil de description plus ou moins pertinent. En R.E., les formes fractales deviennent une conséquence d’un espace formel intrinsèquement irrégulier. La fractalité peut donc être une voie de compréhension du monde utilisant l’espace de ses échelles, c’est-à-dire de ses résolutions. L’objectif central de cette étude est donc de construire une méthodologie fractale générale nécessaire à l’étude d’une morphologie quelconque à travers divers exemples issus de la géographie physique, de la géographie urbaine, de la géohistoire et de la géographie du peuplement. L’objectif final est d’aboutir à des solutions formelles accessibles à une large communauté de géographes, ce qui n’est pas le cas de la théorie de la R.E. dans son formalisme actuel. D’un point de vue épistémologique, le développement en géographie de la R.E. pose la question de la renaturalisation de cette discipline des Sciences humaines et sociales et de sa constitution en science analytique, donc plus largement de proposer une nouvelle définition de la géographie / The most obvious characteristic of the terrestrial interface is its heterogeneity. Phenomenologically, this one, human or natural, show limits that define the forms deployed in geographic space. These limits are certainly due to temporal dynamic, all as much as a scale dynamic. This one is manifested in the possible relationships and variables that exist between scales inasmuch as every scale can no conceive than relative to another that is used as reference. This leads to the scale relativity (SR) which should allow to define intrinsically the geographical space. The first objective is to show the possibility of using SR in geography. At the heart of the SR, we found that fractal geometry is indispensable to try to understand the organization in the scales of the world. So far fractals no were used than as a tool of describing more or less relevant. In SR, the fractal forms become a consequence of a formal space intrinsically irregular. The fractality can be thus a way of understanding of the world using the space of scales, that is to say its resolutions. The central objective of this study is thus to build a general fractal methodology necessary under investigation of an unspecified morphology through various examples resulting from the physical geography, the urban geography, the geohistory and the geography of the settlement. The final objective is to lead to solutions formal accessible at a broad community from geographers, which is not the case of the theory of the R.E in its current formalism. From an epistemological point of view, the development in geography of the R.E raises the question of the Re-naturalization of this discipline of the human and social sciences and of the constitution in analytical science, therefore more largely to propose a new definition of the geography

Este trabalho tem como objetivos estudar a variabilidade das propriedades hidrográficas e da circulação durante ciclos completos de maré, classificar o sistema estuarino com o diagrama estratificação-circulação de Hansen & Rattray, calcular o transporte resultante de sal e a contribuição relativa dos termos advectivos, de difusão turbulenta e a parcela dispersiva, e estudar a influência das alterações ocorridas na descarga fluvial. Medidas de temperatura, salinidade e correntes foram realizadas no verão, outono, inverno e primavera, durante marés de sizígia e quadratura. Os perfis hidrográficos foram executados em intervalos horários durante ciclos completos de maré (13 horas), em três estações fixas (Barra de Cananéia, Baía do Trapandé e sul do Mar de Cananéia). A descarga fluvial média foi estimada através de dados climatológicos históricos da região. Os resultados sugerem mudanças no comportamento hidrodinâmico do sistema após a abertura do canal Valo Grande, com intensificação das correntes e aumento na estratificação vertical da salinidade. O aporte fluvial foi mais intenso (uma ordem de grandeza) que o obtido antes do rompimento da barragem do Valo Grande. As defasagens encontradas entre oscilações e correntes de maré, nas três estações fixas, indicam que a onda de maré se propaga pelo sistema como onda mista. A estação da Barra de Cananéia apresentou os maiores valores médios de salinidade e correntes mais intensas, sendo o oposto para a Baía do Trapandé, sugerindo que as trocas entre as águas oriundas da drenagem continental e da região costeira adjacente são mais efetivas pelo canal do Mar de Cananéia. O transporte de sal foi dominado principalmente pela parcela gerada pela descarga fluvial, seguida (com uma ordem de grandeza menor) pelas parcelas geradas pelo deslocamento da onda de maré (marés de sizígia) ou pela circulação gravitacional (marés de quadratura). As demais parcelas apresentam valores máximos inferiores a duas ordens de grandeza em relação à parcela dominante. A classificação do sistema estuarino-lagunar apresentou variações nas escalas de tempo quinzenal e sazonal, sendo sistema classificado como Tipo 2b no verão e Tipo 2a no inverno, ambos em maré de sizígia. No outono e primavera, o sistema foi classificado como Tipo 2b em marés de sizígia e Tipo 2a em marés de quadratura. / The aim of this work is to examine variations of physical water properties and estuarine circulation during complete tide cycle, to classify the estuary through Hansen and Rattray stratification-circulation diagram, to calculate salt transport and relative contribution of advection process, turbulent diffusion and dispersion, and to study the influences of alterations in fresh water discharge. Temperature, salinity and currents sampling were made in summer, autumn, winter and spring during neap and spring tides. Hydrographic profile measurements were accomplished in three fixed stations (Cananéia Bar, Trapandé Bay and south of Cananéia Sea) in hourly intervals, during a complete tidal cycle (13 hours). The medium fresh water discharge was evaluated through semi-empiric equations based on data climatological reports. The obtained results may suggest hydrodynamic system changes after the opening of the Valo Grande channel with currents intensification and increase in the salinity vertical stratification. The fresh water discharge estimative showed an increase in one order of greatness, if compared to obtained data found in recent works done when Valo Grande channel was closed. The differences found in the oscillation and tide current, in the three studied stations, indicated that the tide wave spreads in the system as a mixed wave. The station of Cananéia Bar presented the largest medium values of salinity and the most intense currents, being the opposite for the Bay of Trapandé, suggesting that the changes among the waters originating from continental drainage and adjacent coastal area are more effective for the Cananéia Sea. The transport of salt was dominated mainly by river discharge, with approximately an order of smaller greatness, followed by portions generated by tide wave displacement (in spring tides) or for the portion generated by the circulation gravitacional (in neap tides). The other portions presented inferior maximum values in two orders of greatness in relation to the dominant portion. The classification of the estuary-lagoon system showed variations in the scales of biweekly and seasonal time, being three fixed stations classified as Type 2b estuary in the summer and Type 2a estuary in the winter. In autumn and spring, during spring tides, the system changes to a Type 2b estuary, and during neap tides to a Type 2a estuary.

Este trabalho tem como objetivos estudar a variabilidade das propriedades hidrográficas e da circulação durante ciclos completos de maré, classificar o sistema estuarino com o diagrama estratificação-circulação de Hansen & Rattray, calcular o transporte resultante de sal e a contribuição relativa dos termos advectivos, de difusão turbulenta e a parcela dispersiva, e estudar a influência das alterações ocorridas na descarga fluvial. Medidas de temperatura, salinidade e correntes foram realizadas no verão, outono, inverno e primavera, durante marés de sizígia e quadratura. Os perfis hidrográficos foram executados em intervalos horários durante ciclos completos de maré (13 horas), em três estações fixas (Barra de Cananéia, Baía do Trapandé e sul do Mar de Cananéia). A descarga fluvial média foi estimada através de dados climatológicos históricos da região. Os resultados sugerem mudanças no comportamento hidrodinâmico do sistema após a abertura do canal Valo Grande, com intensificação das correntes e aumento na estratificação vertical da salinidade. O aporte fluvial foi mais intenso (uma ordem de grandeza) que o obtido antes do rompimento da barragem do Valo Grande. As defasagens encontradas entre oscilações e correntes de maré, nas três estações fixas, indicam que a onda de maré se propaga pelo sistema como onda mista. A estação da Barra de Cananéia apresentou os maiores valores médios de salinidade e correntes mais intensas, sendo o oposto para a Baía do Trapandé, sugerindo que as trocas entre as águas oriundas da drenagem continental e da região costeira adjacente são mais efetivas pelo canal do Mar de Cananéia. O transporte de sal foi dominado principalmente pela parcela gerada pela descarga fluvial, seguida (com uma ordem de grandeza menor) pelas parcelas geradas pelo deslocamento da onda de maré (marés de sizígia) ou pela circulação gravitacional (marés de quadratura). As demais parcelas apresentam valores máximos inferiores a duas ordens de grandeza em relação à parcela dominante. A classificação do sistema estuarino-lagunar apresentou variações nas escalas de tempo quinzenal e sazonal, sendo sistema classificado como Tipo 2b no verão e Tipo 2a no inverno, ambos em maré de sizígia. No outono e primavera, o sistema foi classificado como Tipo 2b em marés de sizígia e Tipo 2a em marés de quadratura. / The aim of this work is to examine variations of physical water properties and estuarine circulation during complete tide cycle, to classify the estuary through Hansen and Rattray stratification-circulation diagram, to calculate salt transport and relative contribution of advection process, turbulent diffusion and dispersion, and to study the influences of alterations in fresh water discharge. Temperature, salinity and currents sampling were made in summer, autumn, winter and spring during neap and spring tides. Hydrographic profile measurements were accomplished in three fixed stations (Cananéia Bar, Trapandé Bay and south of Cananéia Sea) in hourly intervals, during a complete tidal cycle (13 hours). The medium fresh water discharge was evaluated through semi-empiric equations based on data climatological reports. The obtained results may suggest hydrodynamic system changes after the opening of the Valo Grande channel with currents intensification and increase in the salinity vertical stratification. The fresh water discharge estimative showed an increase in one order of greatness, if compared to obtained data found in recent works done when Valo Grande channel was closed. The differences found in the oscillation and tide current, in the three studied stations, indicated that the tide wave spreads in the system as a mixed wave. The station of Cananéia Bar presented the largest medium values of salinity and the most intense currents, being the opposite for the Bay of Trapandé, suggesting that the changes among the waters originating from continental drainage and adjacent coastal area are more effective for the Cananéia Sea. The transport of salt was dominated mainly by river discharge, with approximately an order of smaller greatness, followed by portions generated by tide wave displacement (in spring tides) or for the portion generated by the circulation gravitacional (in neap tides). The other portions presented inferior maximum values in two orders of greatness in relation to the dominant portion. The classification of the estuary-lagoon system showed variations in the scales of biweekly and seasonal time, being three fixed stations classified as Type 2b estuary in the summer and Type 2a estuary in the winter. In autumn and spring, during spring tides, the system changes to a Type 2b estuary, and during neap tides to a Type 2a estuary.

Made available in DSpace on 2016-12-23T13:51:47Z (GMT). No. of bitstreams: 1 Marcelo Dan Scardua - Parte 1.pdf: 3346625 bytes, checksum: b6eec28c5e4cef4dda824006bb5d8c34 (MD5) Previous issue date: 2013-08-29 / O presente trabalho teve por objetivo a avaliação de Modelos Digitais de Elevação (MDEs) para análise espacial de Bacias Hidrográficas (BHs), visando identificar os que apresentam melhor desempenho para a delimitação de bacias hidrográficas. Foram utilizados três tipos de fontes de dados de MDEs, sendo: a) MDEI: proveniente de dados do IBGE, obtido por meio do interpolador Topo To Raster do ArcGIS; b) MDEA: proveniente do sensor GDEM ASTER da National Aeronautics and Space Administration (NASA); e c) MDET: proveniente do projeto Topodata, resultante de um refinamento do SRTM realizado pelo Instituto Nacional de Pesquisas Espaciais (INPE); todos com resolução espacial de 30 metros. Os MDEA e MDET foram adquiridos diretamente da internet. O MDEI foi elaborado a partir de dados cartográficos do IBGE, na escala de 1:50.000, contendo Curvas de Nível (CN) com equidistância vertical de 20 metros e hidrografia. Os MDEs foram utilizados em suas formas originais e refinados, visando a obtenção de MDEs com maior consistência hidrológica. Os MDEs originais (MDEI, MDEA e MDET) foram utilizados diretamente para a delimitação das BHs, usando a extensão ArcHydro (AH) no ArcGIS® 10.1, enquanto os MDEs refinados (MDEIr, MDEAr e MDETr) foram pré-processados usando o algoritmo Agree, para posterior delimitação das bacias utilizando o AH. Realizou-se uma delimitação de referência para fins de comparação com as delimitações automáticas obtidas com as seis opções de MDEs estudadas. A delimitação de referência foi realizada manualmente, em ambiente SIG (ArcGIS), utilizando as referidas cartas do IBGE, contendo CN, hidrografia e pontos cotados. A avaliação das delimitações foi realizada de forma qualitativa, por meio de análise visual, e de forma quantitativa, pelo método das áreas divergentes, ou seja, pelos acréscimos e decréscimos de áreas em relação à delimitação de referência. Foram comparadas também as Hidrografias Numéricas (HN) geradas com e sem refinamento, tendo-se comprovado a eficácia do algoritmo Agree, notandose uma alta semelhança entre as hidrografias refinadas e a de referência. Na comparação das HN sem refinamento, verificou-se que a obtida do MDET apresentou melhor desempenho que a do MDEA, fato que contribuiu para uma melhor eficiência na delimitação das bacias. Das delimitações sem refinamento, a derivada do MDEI foi a que mais se aproximou da delimitação de referência, seguida pelo MDET e MDEA. Quando comparadas as delimitações dos MDEs refinados, o melhor foi o MDEIr; porém, a segunda e a terceira colocação se inverteram, sendo o MDEAr melhor que o MDETr. A consistência hidrológica relativa às alterações na delimitação de bacias pode ser melhor evidenciada quando analisada em microbacias localizadas no interior da bacia hidrográfica / This study aimed to assess digital elevation models (DEMs) from different database in order to identify the ones that best perform watersheds delineation. We used three types of data sources of DEMs: a) DEMI: from the IBGE, obtained by the interpolator Top To Raster in ArcGIS b) DEMA: from ASTER GDEM, a Sensor from the National Aeronautics and Space Administration (NASA), and c) DEMT: from the Topodata project, a result of the refinement of SRTM, conducted by the National Institute for Space Research (INPE), all with a spatial resolution of 30 meters. The DEMA and DEMT were acquired directly from the internet. The DEMI was elaborate from cartographic data of IBGE, at 1:50,000 scale, using the contours lines (CN) with vertical intervals of 20 meters and the hydrography map. The DEMs were used in their original forms and refined to obtain DEMs with greater hidrological consistency. The original DEMs (DEMI, DEMA and DEMT) were used directly for the delimitation of BHs, using the extension ArcHydro (AH) in ArcGIS® 10.1, while the refined DEMs (DEMIr, DEMAr and DEMTr) were pre-processed using the algorithm Agree, for further watershed delineation using. A reference watershed delimitation reference was made to compare with the automatic delimitation obtained with the six options of DEMs studied. The reference delimitation was performed manually in GIS (ArcGIS), using IBGE maps, containing CN, hydrography and elevation points. The assessment of the delimitations was performed qualitatively through visual analysis, and quantitatively, by the method of divergent areas. In other words, the increase and decreases of areas in relation to the reference delimitation. Also it was compared the numerical hydrography (HN) generated with and without refinement. It showed the effectiveness of the algorithm Agree, observing a high similarity between the refined hydrography and the reference hydrography. In the comparison of HN without refinement, it was verified that the one obtained from the DEMT showed better performance than that obtained from the DEMA. At of the delimitations without refinement, the one derived from the DEMI was the closest to the reference delimitation, followed by the derived from DEMT and DEMA. When comparing the delimitations of the refined DEMs, the best one was the DEMIr; however, the second and third position were inverted, being the DEMAr better than DEMTr. Consistency hydrological changes concerning the delimitation of basins can be better evidenced when analyzed in watersheds located within the watershed

Made available in DSpace on 2014-06-11T19:27:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-17Bitstream added on 2014-06-13T19:26:28Z : No. of bitstreams: 1 madruga_fn_me_rcla.pdf: 602399 bytes, checksum: d87f99c9718cfb1252754ffad0a1b32e (MD5) / Os Comitês de Gerenciamento de Bacias Hidrograticas têm sido objeto de uma série de estudos de caso, que apresentam as particularidades da formação, representação e atuação destes Comitês sem situá-Ios em um contexto maior. Neste trabalho procura-se mostrar uma visão geral da importância dada aos problemas ambientais a partir das últimas décadas do século XX, e, em especial, a importância assumida pelas questões de manejo, recuperação e conservação dos recursos hídricos no Brasil. São apresentados de modo detalhado o Sistema de Gerenciamento de Recursos Hídricos do Brasil, de 1997, e de Santa Catarina, de 1994, a fim de mostrar o papel dos Comitês de Gerenciamento de Bacias Hidrográficas nestes Sistemas. Tratando de modo mais específico, foram apresentadas as potencialidades e as dificuldades da atuação e o trabalho dos 16 Comitês de Gerenciamento de Bacias Hidrográficas no Estado de Santa Catarina, dentro da metodologia do Sistema de Gerenciamento de Recursos Hídricos que as idealizou. Por fim, são apontadas as contribuições que a Geografia pode dar ao processo de gestão de recursos hídricos no Brasil. / The Committees of Hydrographic Basins Management have been object of many case studies, witch show the particularities of formation, representation and actuation of these Committees, without pointing out them in a bigger context. In this work the aim is to display a general view of the importance concerning to the enviromental questions from the last decades of the XX century and, specially, the value assumed by the hydrical resources' management, recovering and conservation issues in Brazil. It's detailed Brazil's (1997) and Santa Catarina's (1994) Hydric Resource Management Systems, intending to reveal the role of the committees of hydrographic basins in those Systems. More specifically, have been presented potentialities and difficulties in the actuation and the work of the 16 Committees of Management of Hydrographic Basins in the State of Santa Catarina, within the methodology of the Hydric Resources Management System that idealized them. To conclude, have been pointed out the contributions with which Geography can suply the process of hydrical resources management in Brazil.

Made available in DSpace on 2016-12-08T16:55:41Z (GMT). No. of bitstreams: 1 jonathan.pdf: 8308531 bytes, checksum: a97e8327d7d329321518de8a18b08124 (MD5) Previous issue date: 2012-12-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study analyzes the influence and territorial jurisdictions which may be potentially affecteded by damage and incidence of flash floods and mudslides in the watershed of Ribeirão da Velha, in Blumenau, Santa Catarina. Masterplans, occupation history, urban structure and physical characteristics were recorded for analysis. Also interviews were conducted for data verification of the areas hit by flash floods and mudslides. The flash flood areal range was determined for the 2008 event, aiming to contribute to the mitigation of floods in future territorial jurisdictions. Ribeirão da Velha is a 55 km2 watershed belonging to Itajai River hydrographic basin. Its riverhead is in the municipality of Indaial and it runs into the western region of Blumenau. The mouth of the river is situated in the city center where the waters intersect with Itajai-Acu River. The main objective of this work was to verify if the structured settlement model causes susceptibility to the incidence of flash floods and mudslides in the watershed. In November 2008, occurs a major environmental disaster across the Itajai Valley. Damage caused by water was atypical. By this time, didn t have any other event reported that had caused so much inconveniences and losses of social, environmental and economic to the study area. Ribeirão da Velha watershed passed in recent decades through an intense process of urbanization, which happened in a disorderly manner and without a proper control on the land use. An historic survey (bibliographic) has been achieved related to urban growth in the area and the policies that led to population density. Finally, analyses were made in the areas recently hit by flash floods as well as tematic maps were constructed to outline the main areas affected by the event. / Este trabalho analisa os ordenamentos territoriais e a influência que os mesmos podem provocar na potencialização dos danos e incidência de enxurradas e enchentes na sub-bacia do Ribeirão da Velha, em Blumenau, Santa Catarina. Planos diretores, história de ocupação, estruturação urbana e características físicas foram verificados para a análise. Também foram realizadas entrevistas para verificação de dados das áreas das sub-bacias atingidas por enchentes e enxurradas. Além disso, também foi determinada a mancha de enxurrada da sub-bacia, referente ao evento de 2008, visando contribuir para a mitigação de enxurradas e enchentes em ordenamentos territoriais futuros. O Ribeirão da Velha é uma sub-bacia pertencente à bacia do Rio Itajaí. Sua nascente fica em Indaial e o mesmo percorre toda a região oeste de Blumenau. A foz está situada no centro da cidade onde as águas encontram o Rio Itajaí-Açú. Verificar como o modelo de ocupação estruturado desde a colônia pode ter suscetibilizado a sub-bacia à incidência de enchentes e enxurradas, foi o principal objetivo deste trabalho. Em novembro de 2008 ocorreu um grande desastre ambiental em todo o Vale do Itajaí. Os estragos causados pelas águas foram atípicos, pois até o evento não havia registro de ocorrência que tivesse causado tantos transtornos e prejuízos de caráter social, ambiental e econômico a área de estudo. A área do Ribeirão em questão passou nas últimas décadas por um intenso processo de urbanização, o que aconteceu de forma desordenada e sem um devido controle referente à ocupação do solo. Foi realizado um levantamento histórico (bibliográfico) referente ao crescimento urbano na sub-bacia e as políticas que conduziram ao adensamento populacional. Por fim, foi realizada análise das áreas recentemente atingidas por enxurradas bem como a confecção de mapas que expõem as principais áreas atinjidas por elas

In-situ measurements of surface chlorophyll and zooplankton concentration are compared with in-situ hydrographic measurements and infrared satellite images of the west coast of British Columbia. Their relationships are quantified for a mid-summer and an early winter study period. Winter in-situ hydrographic data showed the shelf to be dominated by Vancouver Island Coastal Current water near-shore, Davidson Current water over the middle shelf, a frontal zone separating these regimes, and North Pacific water over the shelf break. The summer shelf was dominated by topographically induced upwelling in the southern portion of the shelf and stratified regions over the outer shelf and shallow banks further north. Strong northwest winds late in the summer study period induced upwelling along the entire shelf. The surface thermal signature of each of these regimes was identifiable in the satellite imagery. Maximum winter concentrations of chlorophyll and zooplankton were associated with Vancouver Island Coastal Current water and southern portions of the frontal zone. Davidson Current water consistently had the lowest chlorophyll concentrations in the winter study area. Zooplankton concentrations decreased with increasing temperature and distance from shore. The correlation of loge transformed zooplankton concentrations with surface temperature allowed the satellite imagery to explain 49% of the sampled variance. The association of specific chlorophyll concentrations with each hydrographic regime enabled the satellite imagery, in conjunction with an image derived salinity model, to explain 55% of the sampled variance. Image derived plankton models allowed a spatial representation of predicted plankton concentration and the model error. Summer zooplankton concentrations were not consistently related to satellite measured surface temperature but showed a qualitative association with higher chlorophyll concentrations around the outer edge of the upwelling area. Minimum chlorophyll concentrations were found in warm, stratified surface water and intermediate concentrations in the coldest, most recently upwelled water. Maximum concentrations occurred at intermediate temperatures. A least squares fit non-linear equation showed the satellite measured surface temperature patterns explained 72% of the sampled loge transformed chlorophyll variance. Distributions of both zooplankton and chlorophyll concentration retained their association with patterns of sea surface temperature during a wind driven upwelling event. Multivariate cluster analysis of zooplankton taxonomic groups during both winter and summer showed spatial patterns of community composition matched satellite measured patterns of sea surface temperature over the middle and inner shelf. Over the outer shelf, spatial patterns of community structure appeared more closely associated with depth than surface thermal patterns. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Thesis (Ph. D.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 1988. / Includes bibliographical references (leaves 163-172). / A freshwater plume often forms when a river or an estuary discharges water onto the continental shelf. Freshwater plumes are ubiquitous features of the coastal ocean and usually leave a striking signature in the coastal hydrography. The present study combines both hydrographic data and idealized numerical simulations to examine how ambient currents and winds influence the transport and mixing of plume waters. The first portion of the thesis considers the alongshore transport of freshwater using idealized numerical simulations. In the absence of any ambient current, the downstream coastal current only carries a fraction of the discharged fresh water; the remaining fraction recirculates in a continually growing "bulge" of fresh water in the vicinity of the river mouth. The fraction of fresh water transported in the coastal current is dependent on the source conditions at the river mouth. The presence of an ambient current augments the transport in the plume so that its freshwater transport matches the freshwater source. For any ambient current in the same direction as the geostrophic coastal current, the plume will evolve to a steady-state width. A key result is that an external forcing agent is required in order for the entire freshwater volume discharged by a river to be transported as a coastal current. The next section of the thesis addresses the wind-induced advection of a river plume, using hydrographic data collected in the western Gulf of Maine. The observations suggest that the plume's cross-shore structure varies markedly as a function of fluctuations in alongshore wind forcing. Consistent with Ekman dynamics, upwelling favorable winds spread the plume offshore, at times widening it to over 50 km in offshore extent, while downwelling favorable winds narrow the plume width to a few Rossby radii. Near-surface current meters show significant correlations between cross-shore currents and alongshore wind stress, consistent with Ekman theory. Estimates of the terms in the alongshore momentum equation calculated from moored current meter arrays also indicate an approximate Ekman balance within the plume. A significant correlation between alongshore currents and alongshore wind stress suggests that interfacial drag may be important. The final section of the thesis is an investigation of the advection and mixing of a surface-trapped river plume in the presence of an upwelling favorable wind stress, using a three-dimensional model in a simple, rectangular domain. Model simulations demonstrate that the plume thins and is advected offshore by the cross shore Ekman transport. The thinned plume is susceptible to significant mixing due to the vertically sheared horizontal currents. The first order plume response is explained by Ekman dynamics and a Richardson number mixing criterion. / by Derek Allen Fong. / Ph.D.