Visando garantir a disponibilidade hídrica em seus diferentes usos são construídos reservatórios, estes sempre associados a problemas de perda de volume de armazenamento devido ao processo de assoreamento. A atualização destes dados, bem como a quantificação do assoreamento geralmente é feita através de Levantamento Batimétrico. Apesar da grande importância do tema não é observado na literatura um método padronizado para a realização de estudos batimétricos, autores e organizações apresentam métodos dispares quanto à quantidade e disposição dos dados. Deste modo, a presente pesquisa buscou elencar os métodos apresentados na literatura e analisá-los quanto a precisão obtida no cálculo de volume do reservatório, utilizando como estudo de caso o reservatório da UHE Três Irmãos (SP). Observou-se que os MDTs gerados pelos métodos não representavam com fidelidade trechos estreitos do reservatório (braços) bem como o talvegue. Foi então proposto um método para a determinação do espaçamento entre seções bem como uma rotina para geração de MDT considerando características do talvegue. O método proposto para determinação do espaçamento entre seções se mostrou capaz de representar com relativa boa precisão trechos dos braços (diferença máxima encontrada de 5,01%) e apresentou tempo de coleta de dados de 60% do método mais preciso apresentado na literatura. A rotina de geração de MDT proporcionou em média melhora de aproximadamente 30% na qualidade dos dados de volume calculados. Por meio da aplicação dos métodos desenvolvidos na UHE Chavantes foi calculado um assoreamento de 3,91%, de acordo com os resultados, sem a utilização das rotina de geração de MDT desenvolvida cálculo do volume do reservatório seria subestimado em 1,61%, superestimando o cálculo do assoreamento. / Water reservoirs are built with the main purpose of guaranteeing water supply, however, their volume always decreases due the sedimentation processes. Bathymetric surveys can be deployed to assess the current volumetric capacity of a given reservoir and to estimate and quantify the sedimentation process. Although Bathymetric surveys are considered to be a key factor when analyzing and assessing properties of a given reservoir, a standard method for its deployment is yet to be defined. Authors and research groups presents different methods about the sampling rate as well as the choice of adequate spots for data collection. The overall goal of this research was to identify and analyze the different methods deployed in previous published literature analyzing the accuracy of the volume data provided by these different methods. Três Irmãos reservoir (São Paulo) was used as a case study where methods were compared. It was pointed out that the DEMs obtained were unable to accurately represent narrower reservoirs areas (tributaries) and the thalweg. Therefore was proposed a new method for determining the distance among survey sections as well as a routine for DEM generation takes into account the thalweg characteristics. Results revealed that the data pulled out was able to represent with accuracy the tributary areas (maximum difference was 5.01%). In addition, a reduced data collection time was observed (60%) when compared against the most accurate method found in published literature. The proposed technique for DEM generation indicated approximately 30% of quality improvement in the data calculated for the reservoir volume. The developed method was applied on a bathymetric survey conducted on the Chavantes reservoir (São Paulo). The loss of reservoir capacity assessed was 3.19%. According to results, a bathymetric survey which does not deploy the new method proposed would underestimate the reservoir\'s volume by 1.61% and overestimate the sedimentation process.

Visando garantir a disponibilidade hídrica em seus diferentes usos são construídos reservatórios, estes sempre associados a problemas de perda de volume de armazenamento devido ao processo de assoreamento. A atualização destes dados, bem como a quantificação do assoreamento geralmente é feita através de Levantamento Batimétrico. Apesar da grande importância do tema não é observado na literatura um método padronizado para a realização de estudos batimétricos, autores e organizações apresentam métodos dispares quanto à quantidade e disposição dos dados. Deste modo, a presente pesquisa buscou elencar os métodos apresentados na literatura e analisá-los quanto a precisão obtida no cálculo de volume do reservatório, utilizando como estudo de caso o reservatório da UHE Três Irmãos (SP). Observou-se que os MDTs gerados pelos métodos não representavam com fidelidade trechos estreitos do reservatório (braços) bem como o talvegue. Foi então proposto um método para a determinação do espaçamento entre seções bem como uma rotina para geração de MDT considerando características do talvegue. O método proposto para determinação do espaçamento entre seções se mostrou capaz de representar com relativa boa precisão trechos dos braços (diferença máxima encontrada de 5,01%) e apresentou tempo de coleta de dados de 60% do método mais preciso apresentado na literatura. A rotina de geração de MDT proporcionou em média melhora de aproximadamente 30% na qualidade dos dados de volume calculados. Por meio da aplicação dos métodos desenvolvidos na UHE Chavantes foi calculado um assoreamento de 3,91%, de acordo com os resultados, sem a utilização das rotina de geração de MDT desenvolvida cálculo do volume do reservatório seria subestimado em 1,61%, superestimando o cálculo do assoreamento. / Water reservoirs are built with the main purpose of guaranteeing water supply, however, their volume always decreases due the sedimentation processes. Bathymetric surveys can be deployed to assess the current volumetric capacity of a given reservoir and to estimate and quantify the sedimentation process. Although Bathymetric surveys are considered to be a key factor when analyzing and assessing properties of a given reservoir, a standard method for its deployment is yet to be defined. Authors and research groups presents different methods about the sampling rate as well as the choice of adequate spots for data collection. The overall goal of this research was to identify and analyze the different methods deployed in previous published literature analyzing the accuracy of the volume data provided by these different methods. Três Irmãos reservoir (São Paulo) was used as a case study where methods were compared. It was pointed out that the DEMs obtained were unable to accurately represent narrower reservoirs areas (tributaries) and the thalweg. Therefore was proposed a new method for determining the distance among survey sections as well as a routine for DEM generation takes into account the thalweg characteristics. Results revealed that the data pulled out was able to represent with accuracy the tributary areas (maximum difference was 5.01%). In addition, a reduced data collection time was observed (60%) when compared against the most accurate method found in published literature. The proposed technique for DEM generation indicated approximately 30% of quality improvement in the data calculated for the reservoir volume. The developed method was applied on a bathymetric survey conducted on the Chavantes reservoir (São Paulo). The loss of reservoir capacity assessed was 3.19%. According to results, a bathymetric survey which does not deploy the new method proposed would underestimate the reservoir\'s volume by 1.61% and overestimate the sedimentation process.

For realistic predictions of vehicle performance in off-road conditions, it is critical to incorporate in the simulation accurate representations of the variability of the terrain profile. It is not practically feasible to measure the terrain at a sufficiently large number of points, or, if measured, to use such data directly in the simulation. Dedicated modeling techniques and computational methods that realistically and efficiently simulate off-road operating conditions are thus necessary. Many studies have been recently conducted to identify effective and appropriate ways to reduce experimental data in order to preserve only essential information needed to re-create the main terrain characteristics, for future use. This thesis focuses on modeling terrain profiles using the finite difference approach for solving linear second-order stochastic partial differential equations. We currently use this approach to model non-stationary terrain profiles in two dimensions (i.e., surface maps). Certain assumptions are made for the values of the model coefficients to obtain the terrain profile through the fast computational approach described, while preserving the stochastic properties of the original terrain topology. The technique developed is illustrated to recreate the stochastic properties of a sample of terrain profile measured experimentally. To further analyze off-road conditions, stochastic soil properties are incorporated into the terrain topology. Soil models can be developed empirically by measuring soil data at several points, or they can be created by using mathematical relations such as the Bekker's pressure-sinkage equation for homogeneous soils. In this thesis, based on a previously developed stochastic soil model, the polynomial chaos method is incorporated in the soil model. In a virtual proving ground, the wheel and soil interaction has to be simulated in order to analyze vehicle maneuverability over different soil types. Simulations have been created on a surface map for different case studies: stepping with a rigid plate, rigid wheel and flexible wheel, and rolling of a rigid wheel and flexible wheel. These case studies had various combinations of stochastic or deterministic terrain profile, stochastic or deterministic soil model, and an object to run across the surface (e.g., deterministic terrain profile, stochastic soil model, rolling rigid wheel). This thesis develops a comprehensive terrain and soil simulation environment for off-road mobility studies. Moreover, the technique developed to simulate stochastic terrain profile can be employed to simulate other stochastic systems modeled by PDEs. / Master of Science

La génération de formes naturelles a été le sujet de nombreuses recherches depuis plusieurs années. Plusieurs méthodes ont été proposées afin de générer des objets naturels et réalistes tels que des terrains, des plantes et arbres, des nuages, etc. Les modèles itératifs sont très connus dans ce domaine de recherche grâce à leur capacité à générer des formes rugueuses et complexes qui sont adaptées à la représentation d’objets naturels. L’inconvénient majeur de tels modèles est le manque de contrôle sur le résultat final. Ce dernier peut venir de la méthode de construction stochastique interdisant tout contrôle par définition. Pour les modèles dont la construction est déterministe, les paramètres de générations sont souvent non intuitifs et limitent ainsi le contrôle. Pour ces raisons un grand nombre de recherches ont port sur le problème du contrôle de ces modèles ainsi que sur la possibilité d’utiliser des modèles non-itératifs (esquisses, basés exemples, etc.). Bien souvent, le contrôle introduit par ces modèles est un contrôle global, c’est-à-dire sur la totalité de l’objet final et ne prend donc pas en compte les détails locaux de ce dernier. Dans notre travail, nous nous attaquons au problème du contrôle sur les formes naturelles en tenant compte du contrôle local. À cette fin, nous introduisons deux modèles différents. Le premier repose sur un formalisme itératif avec notion de détail qui se dicline en deux sous-familles, l’une basée sur les IFS et l’autre basée sur les surfaces de subdivision. Le deuxième modèle permet l’édition de caractéristiques d’un terrain sous forme de primitives vectorielles puis la génération du terrain par une méthode de diffusion guidée. Cette dernière fait l’objet d’une implémentation parallèle sur la carte graphique (GPU). / The generation of natural shapes has been the subject of much research for many years. Several methods have been proposed to generate realistic natural objects such as terrain, plants and trees, clouds, etc... Iterative models are well known in this field of research due to their ability to generate complex and rough shapes that are adapted to the representation of natural objects. The major drawback of such models is the lack of control over the final result. The latter can come from the stochastic construction method which prevents any control by definition. For models whose construction is deterministic, the parameters of generation are often non-intuitive and thus limit control. For these reasons many studieshave focused on the problem of controlling these models as well as the possibility of using non-iterative models (sketches, based on examples, etc). Often, control introduced by these models is a global control, on the whole final object and therefore does not include local details of this object. In our work, we focus in the problem of control over natural shapes, taking into account local control. To this end, we introduce two different models. The first is based on an iterative formalism with detail concept which is divided into two subfamilies, one based on IFS and the other one based on subdivisionsurfaces. The second model allows the editing of terrain features under a form of vectorial primitives which one used to generate the terrain by guided diffusion method. The latter is the subject of a parallel implementation on graphics card (GPU).

The accuracy of numerical models analyzing hydrologic and hydraulic processes depends largely on how well the input terrain data represents the earth's surface. Modelers obtain terrain data for a study area by performing surveys or by gathering historical survey data. If a modeler desires to create a predictive model to simulate the addition of man-made features such as channels, embankments and pits, he must modify the terrain data to include these features. Doing this by hand is tedious and time consuming. In 2001 Christensen implemented a tool in the Surface-water Modeling System (SMS) software package for integrating man-made geometric features into surveyed terrain data. He called this process feature stamping. While Christensen's feature stamping algorithms decrease the time and effort required to integrate geometric features into existing terrain data, they only function on centerline-based features having a constant trapezoidal cross-section. In addition to placing geometric limitations on the features they stamp, Christensen's feature stamping algorithms also possess several instabilities. These instabilities arise when stamping features that leave the bounds of the terrain data, and when modifying and re-stamping features that have already been stamped. This thesis presents changes and enhancements made to Christensen's feature stamping algorithms. These changes and enhancements completely eliminate the instabilities found in Christensen's feature stamping algorithms and make it possible for numerical modelers to stamp more complex geometric features having compound slopes, asymmetric cross-sections and varying cross-sections along their length. Finally, additional feature stamping algorithms make it possible to stamp radial features such as mounds and pits.

O presente trabalho consistiu no estudo de uma série de atributos do meio físico, como geologia, pedologia, materiais inconsolidados, declividade e menor extensão do percurso da água superficial, entre outros, representados na escala 1:50.000 referentes às bacias hidrográficas dos rios Passa Cinco e Cabeça. Tais atributos foram avaliados, considerando as restrições e potencialidades do meio, buscando uma melhor elaboração das propostas e procedimentos adotados na manutenção da qualidade do meio físico. Para a realização deste estudo, foram utilizados trabalhos já desenvolvidos na área, assim como novos mapas e cartas elaborados durante este, seguindo-se os conceitos da cartografia geoambiental, voltados ao planejamento, proteção e recuperação territorial. Para agilizar os trabalhos de manipulação (armazenamento, recuperação, tratamento, cruzamento e apresentação), foi utilizado um Sistema de Informação Geográfica (SIG-IDRISI), principalmente para obtenção das cartas de Susceptibilidade à Erosão, Potencial à Infiltração e Potencial Agrícola. O resultado final permitiu a obtenção da Carta de Comportamento do Meio Físico como Base para o Zoneamento Geoambiental, onde estão presentes as aptidões, restrições e conflitos de uso, considerando-se neste caso todos os atributos já comentados anteriormente. / Many attributes of the Passa Cinco and Cabeça river hydrographic basins, related to geology, pedology, unconsolidated materials, slope and least water runoff distance, at a 1:50,000 scale, were evaluated. Such attributes based on adequated proposal and procedures were assessed in terms of constraints to determine the basin potentialities. Geoenvironmental cartographic concepts related to planning, protection and management, have been applied in the develop of the charts and maps presented in this works, which, in turn, were base on the extensive research already done in this area. The GIS IDRISI was used to handle data (storing, retrieving, treatment, overlaying and presentation), mainly to elaborate the charts of Erosion Susceptibility, Water lnfiltration Potential and Agricultural Potential. As final result, this work presents an analysis of the environmental attributes to orientate the geoenvironmental zoning, considering all the aspects mentioned above.

O presente trabalho consistiu no estudo de uma série de atributos do meio físico, como geologia, pedologia, materiais inconsolidados, declividade e menor extensão do percurso da água superficial, entre outros, representados na escala 1:50.000 referentes às bacias hidrográficas dos rios Passa Cinco e Cabeça. Tais atributos foram avaliados, considerando as restrições e potencialidades do meio, buscando uma melhor elaboração das propostas e procedimentos adotados na manutenção da qualidade do meio físico. Para a realização deste estudo, foram utilizados trabalhos já desenvolvidos na área, assim como novos mapas e cartas elaborados durante este, seguindo-se os conceitos da cartografia geoambiental, voltados ao planejamento, proteção e recuperação territorial. Para agilizar os trabalhos de manipulação (armazenamento, recuperação, tratamento, cruzamento e apresentação), foi utilizado um Sistema de Informação Geográfica (SIG-IDRISI), principalmente para obtenção das cartas de Susceptibilidade à Erosão, Potencial à Infiltração e Potencial Agrícola. O resultado final permitiu a obtenção da Carta de Comportamento do Meio Físico como Base para o Zoneamento Geoambiental, onde estão presentes as aptidões, restrições e conflitos de uso, considerando-se neste caso todos os atributos já comentados anteriormente. / Many attributes of the Passa Cinco and Cabeça river hydrographic basins, related to geology, pedology, unconsolidated materials, slope and least water runoff distance, at a 1:50,000 scale, were evaluated. Such attributes based on adequated proposal and procedures were assessed in terms of constraints to determine the basin potentialities. Geoenvironmental cartographic concepts related to planning, protection and management, have been applied in the develop of the charts and maps presented in this works, which, in turn, were base on the extensive research already done in this area. The GIS IDRISI was used to handle data (storing, retrieving, treatment, overlaying and presentation), mainly to elaborate the charts of Erosion Susceptibility, Water lnfiltration Potential and Agricultural Potential. As final result, this work presents an analysis of the environmental attributes to orientate the geoenvironmental zoning, considering all the aspects mentioned above.