A presente dissertação apresenta um estudo experimental e de simulação de fluxo de água investigando os efeitos de chuvas torrenciais sobre o solo existente em um talude da região de São Vendelino. Para este estudo foi selecionada uma encosta na qual houve duas ocorrências de rupturas rasas que deram origem a corridas de detritos num evento importante que ocorreu no local em dezembro de 2000. Ao longo da cicatriz deixada por uma delas, foram realizados ensaios de caracterização e determinadas as propriedades hidráulicas do solo a partir de ensaios de campo e de laboratório. Os ensaios de campo compreenderam ensaios com o permeâmetro de Guelph, ensaios com piezômetros de tubo aberto e infiltrômetro de anel duplo. Em laboratório foram realizados ensaios utilizando dois diferentes permeâmetros de parede flexível. Foi feita também a determinação da curva característica do solo através do método do papel-filtro. A partir das propriedades hidráulicas do solo, da geometria do talude e espessura dos materiais, obtidas a partir de topografia, foram realizadas análises de fluxo utilizando o programa Seep/W simulando a precipitação medida de 148 mm/2 h que deflagrou as corridas de detritos de dezembro de 2000. As análises mostraram que, como o solo coluvionar tem uma condutividade hidráulica bastante elevada, ocorre a infiltração de toda a chuva ocorrida. As análises de fluxo mostraram uma elevação progressiva do nível freático com o tempo, o qual atinge a superfície do terreno no trecho crítico do talude (trecho de maior inclinação) após cerca de 95 minutos de precipitação. Análises de estabilidade simplificadas (talude infinito) mostram fatores de segurança próximos da unidade com o nível freático em 80% da camada de solo coluvionar, considerando o trecho mais íngreme do talude. Embora com algumas simplificações de análise, estes resultados mostram que as análises de fluxo e de ruptura, utilizando dados reais medidos em campo, são muito promissores pois conseguem modelar de forma adequada a ruptura ocorrida (FS=1,0). / This dissertation presents an experimental study and a simulation of hydraulic flow in a slope at São Vendelino region, to investigate the effects of torrential rains on the existing soil. A natural slope was selected in which two shallow slope failures had occurred in December 2000 during a serious debris flow event. Soil characterization tests and hydraulic properties have been determined in the laboratory on soil samples taken close to one of the scars left by the failures. The field tests involved Guelph permeameter, stand pipe piezometers and doublering infiltrometer tests. Tests on two different flexible wall permeameter tests and the determination of the moisture-suction characteristic curve have also been carried out in the laboratory. Using the measured soil hydraulic properties, the slope geometry and soil covering depths obtained through topography, some hydraulic flow analyses have been carried out. The SEEP/W software was used and the measured precipitation of 148mm/ 2h, which caused the debris flow event of December 2000, was simulated. The analyses have shown that all the precipitation can infiltrate, as the soil has a large hydraulic conductivity, and there is a progressive rising of the phreatic line with time. This level of water reaches the soil surface in the critical length of the slope (the length with the larger inclination) after 95 min of rain. Simplified slope stability analysis (infinite slopes) had shown values of safety factors close to one in the critical length of the slope when the phreatic line is at 80% depth of the colluvium soil. Although there are some simplifications in the analysis, these results show that the flow and the stability analyses using the real data collected from field tests modeled in an appropriate way the real failure (FS~1,0).

Os atuadores hidráulicos são usados em muitas aplicações e áreas de trabalho devido à sua capacidade para manipular grandes forças com baixa inércia, pouca vibração e capacidade de trabalho por longos períodos de tempo. Entretanto, o maior problema no uso destes tipos de atuadores são as características dinâmicas tais como não-linearidade e variação de parâmetros, as quais dificultam seu controle em malha fechada. Assim, para controlar sistemas hidráulicos, é necessário o uso de modelos matemáticos não lineares e a aplicação de leis de controle complexas para obter um seguimento de trajetória com alta precisão. O objetivo principal deste trabalho é a obtenção de um sistema que siga com precisão as trajetórias de referência do tipo senoidais. Para tanto, este trabalho aborda o projeto de uma lei de controle por realimentação de estados (feedback linearization) combinada com o princípio do modelo interno para aplicar no sistema hidráulico de atuação de uma máquina de ensaios de fadiga. O princípio do modelo interno é aplicado utilizando um compensador dinâmico (que contém pólos imaginários com a mesma freqüência que o sinal de referência) num laço externo do sistema linearizado por realimentação de estados. Uma lei de controle do tipo realimentação de estados, considerando os estados do sistema linearizado e os do compensador dinâmico, é projetada para garantir estabilidade no sistema de malha fechada. A fim de avaliar a estratégia de controle proposta são discutidos e apresentados simulações do modelo experimental. / Hydraulic actuators are used in many applications due to their ability in driving large forces with low inertia and little vibration for a long period of time. However, the main problem in controlling these kinds of systems concerns their dynamics, which presents several nonlinearities and parameters variations. Thus, to control hydraulic systems, appropriated nonlinear models and complex control techniques to achieve a stable force regulation with a specified performance are necessary. The purpose of this work is the application of a feedback linearization scheme in the design of a force controller for a hydraulic actuator used in a fatigue test machine. The main control objective considered regards the achievement of sinusoidal force reference tracking. With this aim the internal model principle is applied by using a dynamic compensator (containing imaginary poles with the same frequency of the force reference) in an outer regulation loop. A state feedback control law, considering both the states of the feedback linearized hydraulic system and the ones of the dynamic compensator, is therefore designed in order to stabilize the whole closed-loop system. Experimental model identification and simulation control results are presented and discussed.

A Plataforma de Stewart é um dos exemplos mais populares dos manipuladores do tipo paralelo, disponibilizando 6 graus de liberdade, apresentando ao mesmo tempo propriedades superiores de precisão e relação peso/carga, quando comparadas com mecanismos do tipo serial, o que a converte em uma opção atrativa para ser aplicada como simulador de movimentos. Neste contexto, o presente trabalho estuda o controle de seguimento de trajetória de um Manipulador Plataforma Stewart (MPS) com atuadores hidráulicos para ser aplicado como simulador de movimentos de navios. O estudo envolve a análise da cinemática, dinâmica, e controle do manipulador, incluindo a modelagem matemática dos cilindros hidráulicos usados como atuadores. Atenção especial é dispendida à formulação da dinâmica do MPS no espaço de juntas, procurando demonstrar a propriedade de antissimmetría das Matrizes de Inércia e Coriolis. O controle proposto foi validado como estável pelo critério de Lyapunov, e, leva em consideração tanto o sistema mecânico da Plataforma de Stewart, quanto o sistema de acionamento hidráulico dos atuadores. Através de simulações de controle usando trajetórias similares às do movimento de um navio, comprovou-se que o sistema proposto consegue disponibilizar fielmente os movimentos de uma embarcação. / The Stewart Platform is one of the most representative examples of parallel manipulators. It has six degrees of freedoms, and superior precision and load/weight ratio when compared to serial manipulators, properties that make them suitable and attractive options for motion simulation applications. In this sense, this work focuses on robust tracking control design for a high load capacity hydraulically driven Stewart Platform manipulator, capable of vessel motion simulations. The kinematic, dynamic and control analysis of the manipulator are presented, as well as a mathematical model of the hydraulic cylinders used as actuators. Especial attention is given to the derivation of the manipulator dynamics formulation, the skew symmetric property of the Inertia and Coriolis matrices is carefully proven in both Cartesian and joint state spaces. The proposed controller takes into consideration the manipulator mechanical dynamics and the actuators hydraulic dynamics. Furthermore, the Lyapunov criteria is used to guarantee control closed loop stability. The control performance is verified by means of computer simulations.

Devido à necessidade de obtenção de uma superfície resistente ao desgaste e a oxidação, os cilindros hidráulicos são tradicionalmente revestidos com cromo duro eletrodepositado. Todavia, este tipo de revestimento apresenta uma redução gradual do coeficiente de atrito, interferindo diretamente na lubrificação da haste, ocasionando danos aos elementos de vedação e promovendo consequentes vazamentos. Outro apelo contrário à utilização do processo de revestimento com cromo é a presença, em elevados níveis, de cromo hexavalente Cr+6, apresentando alto poder cancerígeno e de contaminação ambiental. Atualmente, o processo de aspersão térmica em alta velocidade (HVOF - High Velocity Oxi-Fuel) se caracteriza como uma técnica de revestimento alternativa ao cromo duro, utilizando materiais compósitos (metal-cerâmico), os quais propiciam baixas taxas de desgaste. Este trabalho tem como objetivo avaliar o desempenho de revestimentos aplicados em hastes de cilindros hidráulicos revestidas com WC-CoCr pelo processo HVOF, em comparação ao revestimento de cromo duro eletrodepositado. As técnicas de caracterização empregadas foram divididas em duas etapas, sendo que a primeira foi: análise microestrutural, ensaios de dureza e desgaste, medições de rugosidade e perfilometria, em corpos de prova planos e, na segunda etapa, a análise dos revestimentos adquiridos através de uma bancada de testes de hastes de cilindros hidráulicos, onde a caracterização foi obtida através de, medições específicas dos principais parâmetros de rugosidades aplicadas a superfícies de vedação, como Rz, Rmáx e Rmr, desgaste visuais das hastes e vedações e medições de vazamento de óleo. Ao final, os resultados mostram que o revestimento aspergido, indica características competitivas em relação à eletrodeposição de cromo, podendo ser aplicado em hastes de cilindros hidráulicos com algumas vantagens, como por exemplo, maior resistência ao desgaste, menor coeficiente de atrito, menores taxas de vazamento e melhores condições finais de superfícies. / To obtain a surface that is resistant to wear and oxidation, hydraulic cylinders are typically coated with in hard chromium through the process of electroplating process. However, this type of coating displays a gradual reduction of the friction coefficient as the lubrication directly interferes with the shaft mechanism, which in turn causes damage to the sealing elements and promotes subsequent leakage. Another disadvantage in using the electroplated hard chromium process is the presence of high level hexavalent chromium Cr+6 which is not only carcinogenic, but also extremely contaminating to the environment. Currently, the alternative process of high-speed thermal spraying (HVOF - High Velocity Oxy-Fuel), as opposed to hard chrome coating, uses composite materials (metalceramic) possessing low wear rates. This study aims to evaluate and compare the performance of hydraulic cylinder rods coated with WC-CoCr in the HVOF process, and those coated with electroplated hard chromium. The characterization techniques employed were divided into two steps, the first of which was: microstructural analysis, testing the hardness, wear, roughness and profilometry and on specimens plans and, in the second step, analysis of the coating obtained through a bench test rods of hydraulic cylinders, where the characterization was through achieved , specific measurement of the main parameters of roughness applied to sealing surfaces, as Rz, Rmáx and Rmr, wear visual of the rods and seals and measurements of oil leakage. At the end, the results show that the sprayed coating, indicate competitive characteristics in relation to the electrodeposition of chromium, which can be applied in rods of hydraulic cylinders with some advantages, such as improved wear resistance, coefficient friction low, lower rates of leakage and condition final better surface.

Nesta dissertação estão apresentados os principais conceitos teóricos envolvidos na ação dos jatos formados em dissipadores tipo salto esqui sobre fossa de erosão pré-escavada, desde o trajeto do jato em sua fase aérea e em sua fase submersa, dando especial ênfase às pressões hidrodinâmicas e sua caraterização junto ao fundo da bacia. Para estudar experimentalmente a ação dos jatos nas bacias de dissipação, utilizou-se de um modelo físico de escala 1:100 construído no Laboratório de Obras Hidráulicas do IPH/UFRGS com ensaios de diferentes vazões e diferentes profundidades de fossas pré-escavadas. Os dados foram extraídos dos ensaios no modelo físico através de vasta instrumentação, utilizando-se comportas, pontas linimétricas, piezômetros, sensores de pressão, imagens e outros equipamentos. Foi realizada uma análise criteriosa dos dados gerados no modelo físico a partir das imagens do jato na sua trajetória aérea e no escoamento do jato em sua fase submersa, comparando os dados do modelo aos resultados obtidos por métodos tradicionais de cálculo. Também foram analisados os dados de pressão gerados durante os ensaios, sendo apresentados os resultados relativos às pressões médias e às pressões dinâmicas. As pressões dinâmicas observadas no modelo físico foram comparadas com as calculadas por meio de metodologia teórica abordada na bibliografia com a finalidade de avaliar a qualidade dessa metodologia para aplicação em projetos de engenharia, onde se observou grandes diferenças de magnitude da pressão quando em colchões rasos, e diferenças de distribuição de pressão ao longo do fundo da bacia de dissipação, principalmente quando em colchões profundos. No sentido de ajustar a metodologia aplicada, foi proposta a variação de parâmetros que regulam a forma do bulbo de pressões e a aplicação de um coeficiente de amortecimento de pressões, sendo que assim foi possível melhorar significativamente a distribuição e a magnitude das pressões calculadas devido à ação dos jatos no fundo da bacia de dissipação. Os resultados se mostram satisfatórios até determinada distância após o pico de pressão provocado pelo jato, sendo que após este ponto os efeitos de ressalto hidráulico prevalecem e devem ser pesquisados em estudos futuros. / In this dissertation are presented the main theorical concepts involved in the action of the jets formed in ski jump spillways on stilling basins type pre-excavated scour hole, from the path of the jet in its air stage and in his submerged phase, with particular emphasis on hydrodynamic pressures and its characterization by the bottom of the basin. To experimentally study the action of the jets in stilling basins, was used a physical model in scale 1:100 built in Hydraulic Works Laboratory of IPH/UFRGS with experiments of different flow rates and different depths of pre-excavated scour hole. The data were extracted from experiments on the physical model through extensive instrumentation, using gates, piezometers, pressure sensors, images and other equipment. A careful analysis of the data generated in the physical model from the jet images in your path through the air was performed and the flow of the jet in its submerged phase, comparing the model data to the results obtained by traditional methods of calculation. The pressure data generated during the tests and presented the results for the mean pressures and dynamic pressures were also analyzed. Dynamic pressures observed in the physical model were compared with those calculated by means of theoretical methods for the purpose of evaluating the quality of this methodology for use in engineering projects, where we observed large differences in magnitude of pressure when in shallow water beds, and diferences in pressure distribution over the stilling basin bottom, especially when in deep water beds. In order to adjust the applied methodology, it was proposed to change parameters governing the shape of the pressure bulb and the application of a pressure damping coefficient, and thus was possible to significantly improved the distribution and magnitude of the calculated pressures due to action of the jets in the stilling basin bottom. The results have been satisfactory up to a certain distance after the peak pressure caused by the jet, and after this point the hydraulic jump effects prevail and should be investigated in future studies.

During the late 19th and into the 20th Century, the Tisza River’s vast floodplain-wetland systems were largely disconnected by levees, facilitating "reclamation" for agriculture and resulting in an estimated loss of over 90% of historical wetlands. While levees have been successful in preventing catastrophic flooding for a century, Lower Tisza flood stages continue to rise partially due to aggradation and increased roughness on the confined floodplain. The decrease in the Tisza's current floodway carrying capacity has reduced the flood-protection level of the Tisza's aging levee system. Recently in Hungary, "Room for the River" policies have gained more prominence. For the first of three papers for this dissertation, I assessed eight potential floodplain-reconnection scenarios that would provide more room for the river between Csongrád, Hungary and the Hungary-Serbia border. A novel framework using hydrodynamic and geospatial modeling was used to perform planning-level evaluations of the tradeoffs between floodplain-reconnection scenarios and enhancement of the existing levee system. The scenarios evaluated include levee removal and levee setbacks to strategically reconnect historical wetlands while reducing flood levels. Scenario costs and human population impacts were also assessed. Impacts of reconnecting the Lower Tisza floodplain were compared to heightening levees, the prevailing strategy over the previous century. From a purely construction-cost perspective, heightening Lower Tisza levees is potentially the most cost-effective and politically expedient solution (i.e., impacts the least number of people). However, levee heightening does not solve the long-term problem of reduced flood conveyance, nor does it result in wetland reconnection or enhancement of other floodplain ecosystem services. The suite of reconnection options evaluated provides engineers, planners, and decision makers a framework from which they can further evaluate potential flood-risk reduction options. At least three of the eight reconnection scenarios (setting the western levee back, 1500-meter, and 2000-meter setbacks) along the Lower Tisza demonstrated that floodplain-wetland reconnection is possible while achieving the objectives of minimizing impacts on human populations and reducing flood heights. The Illinois River has a similar history to the Tisza. Levees were constructed, and wetlands were drained during the late 19th and early 20th Centuries. By the mid-1920’s, Illinois River levee systems became increasingly difficult for private landowners and the state to maintain as commodity prices fell and flood levels increased. However, the 1928 U.S. Flood Control act shifted a substantial portion of the burden of flood mitigation from local landowners to the federal government, preventing the dissolution of levee districts. While these levee systems have facilitated floodplain agricultural production and development for the last century, disconnecting the river from its floodplain has led to concerns about the negative impacts of levees on the physical and biological systems of the Illinois River Valley. Recent studies have emphasized approaches that would result in setting back or removing levees in order to naturalize portions of large river-floodplain systems, including the Illinois. The costs and benefits of such projects have shown potential restoration benefits may outweigh potential costs, but these studies have not demonstrated the specific levee districts which have the highest reconnection potential from an economic standpoint. The second paper for this dissertation used geospatial methods to fill this gap by assessing the National Commodity Crops Productivity Index (NCCPI) soil values and agricultural production and profit values for corn and soybeans in 32 individual levee districts along a 235-km segment of the Lower Illinois River. In general, soil productivity index values were lower for Illinois River levee districts compared to the county averages in which the districts are located. Over the five-year study period from 2010-2014, the total agricultural profits in the levee districts ranged from $18-61 million. Several levee districts have relatively low per hectare agricultural values when compared to wetland benefit studies, indicating these protected floodplain areas may be suitable for reconnection. For the third and final dissertation paper I used a novel hydrodynamic, geospatial, economic, and habitat suitability framework to assess the tradeoffs of strategically reconnecting the 125-km La Grange Segment (LGS) of the Lower Illinois River to its floodplain in order to decrease flood risk, improve floodplain habitats, and limit the costs of reconnection. Costs included building-associated losses, lost agricultural profits, and total levee removal and construction costs. Modeled scenarios demonstrated that while flood heights and environmental benefits are maximized through the most aggressive levee setbacks and removals, these scenarios also have the highest economic costs. However, the tradeoff of implementing lower-cost scenarios is that there would be less flood-height reduction and less floodplain habitat available. Several levee districts had high potential for reconnection based on limiting potential damages as well as providing suitable floodplain habitat. To implement large-scale strategic floodplain reconnection along the LGS, opportunity costs ranged from $1.1-$4.3 billion. As such, payments for ecosystem services will likely be necessary to compensate landowners for building losses and decreased long-term agricultural production that result in an overall flood-reduction benefit, increased floodplain wetlands, and most-soil plant habitat.

The Atchafalaya River Basin (ARB) in Louisiana is the principal distributary of the Mississippi River, and it contains the largest contiguous area of baldcypress-water tupelo swamp forests in North America. After designation of the ARB as a federal floodway following the destructive 1927 Mississippi River (MR) flood, it was extensively modified to accommodate a substantial portion of the MR flow (~30%) to mitigate flooding in southern Louisiana. The resulting reach to system scale modifications for regional flood mitigation, navigation, and hydrocarbon extraction have substantially altered the lateral connectivity between the AR and its floodplain wetlands, threatening the ecological integrity of this globally-important ecosystem. Multiple stakeholder groups agree that restoring flow connectivity is essential to maintaining the basin’s water quality and forest health, and several flow-connectivity enhancement projects (hereafter, project elements) have been proposed by the Atchafalaya Basin Program’s Technical Advisory Group within the Flat Lake Water Management Unit (FLWMU) study area to increase lateral hydrologic connectivity within the management unit and beyond. Additionally, a new flow prescription to improve floodplain habitat has recently been suggested for the ARB. Flow into the ARB is now regulated through the Old River Control Structure (ORCS; operational in 1963), and represents the opportunity for large-scale flow experiments to enhance a multitude of ecosystem services that have been degraded due to anthropogenic alteration. For this study, I compiled existing datasets and constructed a 1D2D hydraulic model to evaluate: 1) if the suggested flow prescription would have the desired inundation impacts; 2) whether the proposed project elements would improve lateral connectivity in the FLWMU; and 3) whether recommended project elements would increase the area suitable for baldcypress recruitment in the study area. To examine the first two research questions above, I examined two scenarios – a baseline scenario to examine current conditions (no restoration projects), and a full-implementation scenario, where all proposed project elements that could be examined at the model resolution were implemented. Comparison of the modeling results for the baseline scenario to the suggested flow prescription goals suggests the overbank discharge and the extreme low-flow targets would have the desired impacts of inundating and drying out of the majority of the FLWMU, respectively. Proxy indicators of enhanced flow connectivity suggest that proposed projects will improve water quality, especially at intermediate to high flow conditions, when ~90% of the FLWMU experiences improved drainage as indicated by higher rates of water surface elevation decrease and lower overall system water volume. The stated objectives of the project elements recommended by the Technical Advisory Group are to improve connectivity and water quality, but another important and related restoration goal for stakeholders includes baldcypress restoration. To examine the third objective, I used a model-derived proxy indicator of habitat improvement (depth reduction) at two key discharges, along with other ecological suitability factors, to determine areas most likely to support baldcypress recruitment. Here, I compared baseline conditions to two alternative restoration scenarios – 1) a targeted implementation scenario where 22 project elements were implemented, and 2) the full-implementation scenario, where all projects that could be examined at the model resolution were implemented. Suitable habitat area for both natural and artificial baldcypress recruitment increased under intermediate flow conditions but remained unchanged for higher discharge conditions. For the intermediate discharge scenario, the full-implementation scenario results in a 2 km2 increase in the class considered most suitable for natural baldcypress regeneration within the calculated recruitment band, and a decrease of ~16 km2 in the areas considered least suitable for the entire FLWMU study area. Coupled with the connectivity results, which indicate that nutrient-rich river water will be exchanged between main channels and the backswamp at a greater range of flows, it appears that project implementation alone will benefit baldcypress recruitment, especially artificial regeneration efforts. However, full project implementation coupled with large-scale flow modifications at ORCS would likely provide maximum benefit for baldcypress restoration efforts that seek to increase the area supportive of natural baldcypress regeneration.

The Willamette is a gravel-bed river that drains ~28,800 square kilometers between the Coast Range and Cascade Range in northwestern Oregon before entering the Columbia River near Portland. In the last 150 years, natural and anthropogenic drivers have altered the sediment transport regime, drastically reducing the geomorphic complexity of the river. The purpose of this research is to assess longitudinal trends in sediment transport within the modern flow regime. Sediment transport rates are highly discrete in space, exhibit similar longitudinal patters across flows and increase non-linearly with flow. The highest sediment transport rates are found where the channel is confined due to disconnection of the floodplain and the river runs against high resistance terraces. The spatial distributions of sediment transport rates and active gravel are tightly linked. Sediment sampling revealed slight downstream fining in the surface grain size. Sediment size did not correlate with stream power.

Doctor of Philosophy / Department of Civil Engineering / Stacey E. Tucker-Kulesza / Surface soil erosion is a widespread problem that impacts the natural and built environment. Many disciplines, such as hydrology, soil science, agriculture, and geotechnical engineering, have investigated soil erosion. Although empirical equations to predict soil erosion exist, they are typically inaccurate, so several devices have been developed to quantify the erodibility of soil. The erosion function apparatus (EFA) was developed to predict the erosion potential of soil for evaluating bridge scour; however, it has been used for several other geotechnical applications. The main disadvantages of the EFA are that it is unable to directly measure the shear stress, it remains operator dependent, and it is time consuming as a standard test requires at least eight hours. Moreover, as erosion occurs, it affects the water quality and makes it difficult to observe the soil sample surface during the test, affecting the operator judgement. The research objective of this project is to instrument the EFA to address the limitations of the device. A stereo-photogrammetry system was developed to measure the soil surface roughness following an EFA test and reduce operator dependency. Turbidity sensors were added to provide a secondary measurement of erosion. The newly instrumented EFA was used to develop a new methodology for interpreting erosion results. Lastly, the new methodology and instrumentation were used to explore the influence of natural and engineered soil properties on soil erosion.

MELO, Juliana Barroso de. O licenciamento ambiental e a atuação do poder público na realização do aterro hidráulico da Praia de Iracema. 2005. 139 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Programa Regional de Pós-Graduação em Desenvolvimento e Meio Ambiente-Prodema, Fortaleza-CE, 2005. / Submitted by guaracy araujo (guaraa3355@gmail.com) on 2016-04-29T17:27:40Z No. of bitstreams: 1 2005_dis_jbmelo.pdf: 1875715 bytes, checksum: aca50422c5eaab571ad1010726d7d44c (MD5) / Approved for entry into archive by guaracy araujo (guaraa3355@gmail.com) on 2016-04-29T17:43:34Z (GMT) No. of bitstreams: 1 2005_dis_jbmelo.pdf: 1875715 bytes, checksum: aca50422c5eaab571ad1010726d7d44c (MD5) / Made available in DSpace on 2016-04-29T17:43:34Z (GMT). No. of bitstreams: 1 2005_dis_jbmelo.pdf: 1875715 bytes, checksum: aca50422c5eaab571ad1010726d7d44c (MD5) Previous issue date: 2005 / The occupation of the costal area in Fortaleza along the last two decades has had touristic trade as the main segment. As a consequence there has been the fast occupation of this area by enterprise buildings besides other construction work aiming to make the coastal area more suitable for the demands of the touristic trade. As an example we mention the praia de Iracema hydraulic embankment (aterro hidráulico) that has caused negative impact on the coastal ecosystem such as interference on the dynamic of the tides as well as damage on the characteristics of the coastal landscape. According to the title “Environmental licensing and interventions of the Public Power on the coastal area of Fortaleza – Ceará: considerations on the praia de Iracema hydraulic embankment” this research work aims to show the importance of environmental licensing as a means to control the accomplishment of public as well as private construction work and consequently the better occupation of the coastal area along Fortaleza. The lack of an adequate ordering in the use and occupation of the coastal urban area along Fortaleza tends to maximize the problem of its exaggerated use thus causing damage to the environmental resources. It is crucial the development of preventive public policies aiming a better ordering and planning of the use of the coastal urban space allowing the preservation of natural resources and giving more guarantee to the sustainability of the economical activities, mainly tourism. For all these reasons and having in mind the ideal of sustainability of the coastal areas of the cities it is fundamental that the Public Power take good care of the established law and make use of preventive instruments such as the previous study of environmental impactand environmental licensing where all parts be effectively integrated and aiming the maintenance of good living conditions. / A ocupação do litoral de Fortaleza, ao longo das duas últimas décadas, apresentou como principal vetor o turismo. Como conseqüência houve acelerada ocupação dessas áreas, com a edificação de empreendimentos, além da realização de obras com o objetivo de melhor adequar o litoral para as demandas do setor turístico, como exemplo o aterro hidráulico da praia de Iracema, causando impactos negativos no ecossistema costeiro, como a interferência na dinâmica das marés e a descaracterização da paisagem costeira. Pelo título “O licenciamento ambiental e as intervenções do Poder Público na zona costeira de Fortaleza-CE: considerações sobre o aterro hidráulico da praia de Iracema”, a presente pesquisa tem como finalidade demonstrar a importância do instrumento de licenciamento ambiental para realização de obras públicas, além das privadas, e, conseqüentemente, a obtenção de um melhor uso e ocupação da orla marítima de Fortaleza. A ausência de uma adequada ordenação do uso e ocupação do solo urbano-litorâneo tende a maximizar o problema da utilização exacerbada – e, conseqüentemente, danos - dos recursos ambientais. Por essa razão, orientando-se pelo ideal da sustentabilidade nas zonas costeiras das cidades, é fundamental que o Poder Público zele pelas normas vigentes e faça uso de instrumentos preventivos, como a realização de estudos prévios de impactos ambientais e o licenciamento ambiental, onde todos estejam efetivamente integrados e voltados para a manutenção da qualidade de vida.