Malgré les préoccupations environnementales et climatiques, le charbon thermique reste la première source d'énergie utilisée dans la production d'électricité au monde. Face à une très forte demande mondiale, le marché maritime du charbon thermique se développe considérablement. Depuis les années 2000, ce dernier fait face à des changements structurels économiques importants. L'objectif de cette thèse est d'apporter une analyse structurelle du marché maritime du charbon thermique depuis les années 2000. À travers cette analyse, nous cherchons à expliquer l'évolution de ce marché et à déterminer les facteurs économiques et institutionnels permettant d'expliquer sa configuration. Cette thèse est constituée de trois chapitres. Dans le premier chapitre, nous définissons le marché selon les critères de produit. Nous décrivons par la suite la chaîne de valeur de l'industrie du charbon thermique afin de souligner les facteurs expliquant l'évolution de cette industrie, notamment depuis les chocs pétroliers des années 1970. Dans le deuxième chapitre, nous analysons de façon empirique la configuration du marché maritime du charbon thermique et son évolution entre 2000 et 2010. Cette analyse souligne la mesure selon laquelle les coûts du transport maritime et du fret sont susceptibles de représenter une barrière à l'entrée pertinente sur ce marché. Finalement, dans le troisième chapitre, nous déterminons le(s) facteur(s) permettant d'expliquer le schéma et la configuration du marché mondial du charbon thermique. Pour ce faire, nous modélisons théoriquement le comportement des exportateurs et leur stratégie d'entrée face à des coûts unitaires du fret et du transport maritime sur le marché mondial dans un cadre structurel prédéfini en amont. / Despite the environmental and climate concerns, steam coal is still the first thermal energy used in the electricity generation worldwide. Faced to an increasing global demand, the steam coal seaborne market is developing considerably. From the 2000s, the steam coal maritime market faces several economic structural changes. The aim of this PhD dissertation is to bring a structural analysis of the steam coal maritime market from the 2000s. Through this research, we want to determine the economic and institutional factors helping to explain the configuration of the market. This PhD thesis involves three chapters. In the first chapter, we define the market over product space. Then, we describe the value chain of the steam coal industry in order to highlight the factors explaining the evolution of the industry, particularly by the oil crisis in the 1970s. In the second chapter, we empirically analyze the configuration of the steam coal maritime market and its evolution from 2000 to 2010. This analysis emphasizes the degree by which the seaborne transport costs and freight costs may represent a relevant barrier to entry on the market. Finally, in the third chapter, we determine the factor(s) explaining the schema and the configuration of the world steam coal market. To do so, we model the exporters’ behavior and their entry strategy faced to unit freight and seaborne costs in a predefined market structure.

This thesis addresses plumbing systems for manufacturing building. The theoretical part explores ways of draining stormwater. Experimental part is measuring consumption of water. Project part solves plumbing systems in specified manufacturing building.

Pour fournir des simulations fiables, les modèles hydrologiques nécessitent usuellement le calage de leurs paramètres sur des données de débit. Toutefois, ces dernières sont limitées et la plupart des bassins versants sont non jaugés. Des méthodes alternatives regroupées sous le terme de 'régionalisation' sont alors nécessaires pour estimer les paramètres des modèles. La thèse propose de combiner les trois méthodes les plus classiques afin de régionaliser les paramètres d'un modèle distribué sur deux grands bassins versants français : la Loire à Gien et la Durance à Cadarache. À partir des trois méthodes de régionalisation, le degré de spatialisation est adapté aux différents paramètres du modèle d'après leurs caractéristiques et leur rôle hydrologique. In fine, l'approche multi-méthode et multi-motif proposée (i) réduit considérablement le nombre de degrés de liberté du modèle, (ii) améliore la représentation de la variabilité physique du bassin et (iii) améliore très nettement les performances des simulations. En contexte non jaugé, la spatialisation des paramètres permet un gain d'environ 10 %, l'approche multi-méthode et multi-motif apportant en particulier un gain d'environ 7 % par rapport à une méthode de régionalisation unique. Malgré ces gains, l'impact de la spatialisation des forçages météorologiques demeure 6 fois plus important que spatialisation des paramètres. / To provide reliable simulations, hydrological models usually require the calibration of their parameters over streamflow data. However, the latter are limited and most of the catchments remained ungauged. Consequently, alternative methods termed ‘regionalization’ are needed to estimate model parameters. The thesis proposes to combine the three classical methods in order to regionalize the parameters of a distributed model over two large French catchments: the Loire catchment at Gien and the Durance catchment at Cadarache. On the basis of the three regionalization methods, the degree of spatialization is adapted to the different model parameters according to their characteristics and their hydrological role. In fine, the proposed multi-method and multi-pattern approach (i) significantly reduces the number of degrees of freedom, (ii) improves the representation of the catchment physical variability, and (iii) significantly improves the performance of the simulations. In the ungauged context, the parameter spatialization allows an improvement of about 10%, and in particular, the multi-method and multi-pattern povides an improvement of about 7% compared to a single regionalization method. Despite these improvements, the impact of the climatic input spatialization remains 6 times greater than th parameter spatialization.

A study of the Abrahamskraal Formation in the area around Merweville, in the southwestern corner of the Karoo Basin has revealed the presence of traceable lithological units with lateral continuity throughout the study area. The stratigraphic section measured in this part of the basin matches the section measured by Jordaan, (1990) south of Leeu Gamka, with a basal arenaceous unit overlain by a predominantly argillaceous succession. The thickness of the Abrahamskraal Formation in this part of the Karoo Basin in 2565m, charactersized by a braided depositional environment in the lower 2075m and a meandering depositional environment in the upper 490m. Biostratigraphically the succession comprises a basal Eodicynodon Assemblage Zone which constitutes the lower 1104m and this is overlain by a 1461m thick Tapinocephalus Assemblage Zone whose upper limit is 21m below the Poortjie Member of the Teekloof Formation. This study has also corroborated the work by earlier authors who proposed a northeasterly palaeoflow direction as well as contributing to the global correlation of the Middle Permian terrestrial tetrapod faunas where the Eodicynodon Assemblage Zone correlates with the fauna from the Russian Ocher & Ischeevo; fauna of China’s Xidagou Formation and Rio da Rosto fauna of Brazil while the Tapinocephalus Assemblage Zone fauna corrletaes with fauna from Mezen and Ischeevo in Russia, Posto Queimado fauna in Brazil and those from the Madumabisa strata of Zimbabwe.

En esta investigación se realiza el análisis hidrológico de la cuenca Utcubamba, y posteriormente el análisis hidráulico del río Utcubamba, para así, poder obtener un mapa de inundación que permita identificar las zonas susceptibles a este fenómeno, en el distrito del Milagro, departamento de Amazonas. Para poder realizar el mapa de inundación, se parte del análisis hidrológico que consta de delimitar la cuenca Utcubamba, determinar sus características, mediante el software ArcGis. Previamente, se tendrá que recolectar los registros de precipitación de las diferentes estaciones pluviométricas, donde mediante métodos probabilísticos y pruebas de bondad, y estimando los datos faltantes, se puede obtener los hietogramas de diseño para lograr la obtención de las avenidas máximas (caudales de diseño) para diferentes tiempos en que se va a retornar y que se han propuesto. Para el análisis hidráulico, se necesita realizar visitas a campo, para poder hallar el factor de rugosidad más apropiado para el río, y además para obtener un panorama más amplio sobre el lugar de estudio. Se obtendrán las curvas de nivel y la batimetría, datos fundamentales para el modelamiento y obtención de secciones transversales del río. Para ello, se usará el modelo matemático HEC-RAS. Y así con la intervención de los programas y el análisis propuesto se podrá obtener el mapa de inundación y así dar la alternativa de solución más adecuada al problema que se pueda generar / In this research, the hydrological analysis of the Motupe basin is carried out, and later the hydraulic analysis of the Motupe river, in order to obtain a flood map that allows identifying the areas susceptible to this phenomenon, in the district of Milagro, Amazonas. In order to carry out the flood map, we start from the hydrological analysis that consists of delimiting the Utcubamba basin, determining its characteristics, with the help of the ArcGis program. Previously, the precipitation data from the different rainfall stations will have to be collected, where by means of probabilistic methods and goodness tests, and estimating the missing data, the design hietograms can be obtained in order to obtain the maximum flows (design flows) for different proposed return times. For hydraulic analysis, field visits are required to determine the most appropriate roughness coefficient for the river, and also to obtain a broader view of the study site.,contour lines and bathymetry will be obtained, fundamental data for modeling and obtaining cross sections of the river. For this, the mathematical model HEC-RAS will be used. And thus, with the intervention of the programs and the proposed analysis, it will be possible to obtain the flood map and thus provide the most appropriate alternative solution to the problem that may be generated.

<p>Streamflow prediction in ungauged basins (PUB) is a process generating streamflow time series at ungauged reaches in a river network. PUB is essential for facilitating various engineering tasks such as managing stormwater, water resources, and water-related environmental impacts. Machine Learning (ML) has emerged as a powerful tool for PUB using its generalization process to capture the streamflow generation processes from hydrological datasets (observations). ML’s generalization process is impacted by two major components: data splitting process of observations and the architecture design. To unveil the potential limitations of ML’s generalization process, this dissertation explores its robustness and associated uncertainty. More precisely, this dissertation has three objectives: (1) analyzing the potential uncertainty caused by the data splitting process for ML modeling, (2) investigating the improvement of ML models’ performance by incorporating hydrological processes within their architectures, and (3) identifying the potential biases in ML’s generalization process regarding the trend and periodicity of streamflow simulations.</p><p>The first objective of this dissertation is to assess the sensitivity and uncertainty caused by the regular data splitting process for ML modeling. The regular data splitting process in ML was initially designed for homogeneous and stationary datasets, but it may not be suitable for hydrological datasets in the context of PUB studies. Hydrological datasets usually consist of data collected from diverse watersheds with distinct streamflow generation regimes influenced by varying meteorological forcing and watershed characteristics. To address the potential inconsistency in the data splitting process, multiple data splitting scenarios are generated using the Monte Carlo method. The scenario with random data splitting results accounts for frequent covariate shift and tends to add uncertainty and biases to ML’s generalization process. The findings in this objective suggest the importance of avoiding the covariate shift during the data splitting process when developing ML models for PUB to enhance the robustness and reliability of ML’s performance.</p><p>The second objective of this dissertation is to investigate the improvement of ML models’ performance brought by Physics-Guided Architecture (PGA), which incorporates ML with the rainfall abstraction process. PGA is a theory-guided machine learning framework integrating conceptual tutors (CTs) with ML models. In this study, CTs correspond to rainfall abstractions estimated by Green-Ampt (GA) and SCS-CN models. Integrating the GA model’s CTs, which involves information on dynamic soil properties, into PGA models leads to better performance than a regular ML model. On the contrary, PGA models integrating the SCS-CN model's CTs yield no significant improvement of ML model’s performance. The results of this objective demonstrate that the ML’s generalization process can be improved by incorporating CTs involving dynamic soil properties.</p><p>The third objective of this dissertation is to explore the limitations of ML’s generalization process in capturing trend and periodicity for streamflow simulations. Trend and periodicity are essential components of streamflow time series, representing the long-term correlations and periodic patterns, respectively. When the ML models generate streamflow simulations, they tend to have relatively strong long-term periodic components, such as yearly and multiyear periodic patterns. In addition, compared to the observed streamflow data, the ML models display relatively weak short-term periodic components, such as daily and weekly periodic patterns. As a result, the ML’s generalization process may struggle to capture the short-term periodic patterns in the streamflow simulations. The biases in ML’s generalization process emphasize the demands for external knowledge to improve the representation of the short-term periodic components in simulating streamflow.</p>

Water management is facing a growing number of challenges in many river basins worldwide, as the equal distribution of the available water resources is increasingly influenced by several, uncertain climatic and anthropic pressures. Within the current and projected water scarcity and drought scenario, such issue represents even a greater challenge in those basins that have been massively regulated in the XX century, as water managers are asked to find balanced policies to stay ahead with multiple, interdependent and ever-increasing water-related requirements. In this context, water conflict has become a recurring problem, with the freshwater ecosystems becoming the sole providers of unbearable human water needs and experiencing a severe alteration of their natural renewability and ecological integrity. In fact, the concern of sustaining the freshwater ecosystems has evolved throughout the years, coming to the fore since the 1990s under the concept of "ecosystem services", defined as the multiple benefits that people obtain from ecosystems. With a high number of challenges still ahead for implementing such paradigm in real-world water management practices, few investigations inspect the long-term evolution of highly regulated basins, being vulnerable freshwater systems characterized by a profusion of ecosystem services in a context of complex management policies and changing anthropic and climatic pressures. We focus our attention on the highly interconnected Garda-Mincio system (Northern Italy), further broadening the results to the regulated basins of the European perialpine region. First, to examine the modification of the freshwater systems from their pristine to their regulated conditions, we carried out an extensive collection of daily hydro-meteorological data by consulting public online sources as well as digitizing historical data contained in hand-written documents. The resulting database, which represents a valuable source of long-term daily hydro-meteorological data for the Garda-Mincio system, additionally underscored the complexity of constructing and maintaining a consistent and up-to-date database within an inter-regional context. The collected data were then adopted to investigate the climatic and anthropogenic drivers that have progressively influenced water availability, the provision of the changing water demands and the trade-offs with the existing water ecosystem services over the last two centuries. Statistical analyses were performed to outline the evolution of the annual and seasonal trends of Lake Garda water levels and outflows over the period 1888-2020, discussing the role of the Salionze Dam operational rules (completed in 1951) as well as the influence of the main water needs of the downstream Mincio River basin (i.e. hydropower production, irrigation and fluvial ecosystem sustenance). The role of hydro-meteorological factors was assessed by implementing a water balance model for Lake Garda, the largest lake in Italy, over the period 1928-2020, performing uncertainty and sensitivity analyses on specific water balance components (i.e. over-lake evaporation and basin evapotranspiration). We then focus our analyses on the management of the hydraulic infrastructures that regulate the first and highly water-stressed stretch of the Mincio River downstream Lake Garda, i.e. the Salionze Dam and the Pozzolo-Marenghello infrastructures, where both high and low flow conditions reveal the inability of the current operational rules to support the new variety of water abstractions while maintaining appropriate environmental flow conditions and flood protection. These analyses were carried out through in-situ measurements and numerical simulations, updating the aging rating curves of the existing hydraulic infrastructures. Drawing on the Garda-Mincio system, we inspected the evolution of the freshwater regimes within the European perialpine lakes framework, discussing the outcomes to describe which common factors drove management policies in the area. Eventually, we discuss our outcomes recommending future sustainable and adaptive water management policies in the area.

Nutrient enrichment, which can be detrimental to the health of aquatic systems, is one of the leading causes of impairment of our Nations? waters. Development and initial calibration of a hydrologic, hydrodynamic, and water quality model of dissolved oxygen and nutrient concentration for the St. Louis Bay watershed in coastal Mississippi is documented herein. The model was developed using the USEPA BASINS 3.0 analysis system and WinHSPF, a comprehensive watershed loading and transport modeling software. The resulting model simulates significant watershed and instream physical, chemical and biological processes including rainfall runoff and associated water quality from a variety of land use categories. Extensive data describing the study area, land use practices, hydrology and water quality are presented, analyzed and discussed relative to model development and adequacy to support future modeling projects. Integration of this data into a valuable water quality assessment model and preliminary model calibration is also presented.

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Water resource management is a multifaceted issue that becomes more complex when considering multiple nations’ interdependence upon a single shared transboundary river basin. With over 200 transboundary river basins worldwide shared by two or more countries, it is important to develop tools to allow riparian countries to cooperatively manage these shared and often limited water resources. Cooperative game theory provides tools for determining if cooperation can exist across jurisdictional boundaries through a suite of mathematical tools that measure the benefits of cooperation among basin stakeholders. Cooperative game theory is also useful for transboundary negotiation because it provides a range of solutions which will satisfy all players in the game and provides methods to fairly and equitably allocate the gains of that cooperation to all participating stakeholders, if that cooperation is shown to be possible. This dissertation applies cooperative game theory concepts to the Rio Grande/Bravo basin in North America as a case study. The Rio Grande/Bravo forms the 1,200 km border between the United States and Mexico. A comprehensive water resources planning model was developed for the basin including the major water users, water related infrastructure including reservoirs, and water policy logic related to the bi-national water sharing agreements. The water planning model is used to calculate the characteristic functions for the cooperative game analysis. For the Water Demand Reduction Game, the largest agricultural users, District 005, District 025 and the Texas Watermaster Section below Falcon were defined individual players. The cooperative analysis was between the individual players rather than the countries. In addition to the cooperative analysis, performance measures for water deliveries were calculated to determine if water delivery was improved to each player under the cooperative game. The results show that the amount of additional water to the downstream players may not be large enough to induce cooperation. The small amount of increase in water deliveries is related to the large system losses as the water travels downstream over a long distance and a division of water under the 1944 Treaty between the United States and Mexico. / text