L'image de la ville de Bénarès (Kāśī, Varanasi) est liée à son ensemble de ghāṭ – berges en forme de gradins – qui se déploie de façon monumentale sur la rive concave d'un méandre du Gange. L'aménagement de ce front d'eau s'inscrit dans un contexte culturel particulier qui nécessite un rapport de proximité avec l'eau du fleuve. La construction et le développement de ce front d'eau dans le temps et la manière composite dont les éléments architecturaux s'y sont intégrés, interrogent aujourd'hui cette grande unité urbaine qui forme un espace public de plus de 6 km de long. L'objectif de cette thèse est de comprendre les éléments qui ont concouru à la naissance et au développement de ce front. La forme architecturale et urbaine du ghāṭ est considérée comme un dispositif construit modulable adapté à un milieu fluvial, à une topographie et à des pratiques liées à la culture du lieu, qui facilite l'accès à l'eau quel que soit son niveau. M'appuyant sur des images anciennes, sur une série d'enquêtes de terrain et de relevés architecturaux, ainsi que sur des plans de travaux officiels, j'étudie les techniques de construction face aux contraintes de l'eau, j'observe et j'analyse le dialogue de cette forme de berge avec la géographie et le paysage urbain pour en mieux approcher son architecture et j'explique la matérialisation du ghāṭ par les pratiques diverses qui s'y déploient et les parcours symboliques qui y font référence. La relation toute particulière que la ville entretient avec son fleuve par l'architecture des ghāṭ explique son potentiel urbanistique inhérent à son développement dans le temps et le long de la berge / The image of Benares (Kāśī, Varanasi) is closely associated to the architecture of its riverfront composed of ghats – steps and terraces – that stretch out in a monumental way on the concave bank of a meander formed by the river Ganges. The expansion of this riverfront has to be understood in relation to a cultural tradition that demands a close proximity to the waters of the river. The construction and development of this riverfront in time and the various ways in which each architectural element is integrated with the river bank, calls into question its impressive urban unity that forms a public space extending more than 6 km. The aim of this thesis is to identify the elements that have contributed to the origin and the development of this front. The architectural and urban form of the ghat is considered as a constructed flexible device adapted to a specific river environment, a characteristic topography and to practices linked to the culture of the place, which allows for easy access to the varying levels of the river's water level. Based on pictorial archives, interviews, measure drawings done on site and on official planners' drawings, I examine the techniques of hydraulic constructions best adapted to counter the river's currents, I observe and analyze the relations between the riverbank, the geography and the urban landscape so as to better approach the ghats' architecture and I explain the materialization of the ghat through the diverse practices and the symbolic trajectories that surround it. The particular relation that the city entertains with its river, through the architecture of ghats, explains its urban potential inherent to its development in time and space i.e. along its river bank

The Riverbank Filtration (RBF) water supply system Karany has been affected by increasing NO3- concentrations during recent decades. This thesis deals with flow and chemical composition of groundwater in Skorkov and Sojovice RBF systems, which are the most problematic ones according to their quality in long term. Twelve new groundwater wells (V1- V12) were drilled in study area in 2013. Data derived from the wells were used to improve the conceptual hdrogeological model of the area and I tried to specify information about the origin of nitrate pollution. The Groundwater level logging showed hydraulic connection between the river and the wells situated up to 130 m faraway from the river (V1, V2 andV10), which were also demonstrated by the short- term temperature fluctuations caused by fast penetration of surface water from The Jizera River during higher flow rate to wells. I compiled geological sections which show the geometry of The Quaternary fluvial deposits and groundwater level. The chemical analysis of groundwater showed that it is not possible to differentiate groundwater from the shallow part of The Cretaceous aquifer from the aquifer of fluvial deposits by major chemical components. The result of infiltration experiments showed higher permeability in the environment with grass cover (kv=...

Les berges de cours d'eau constituent des zones d'interface (ou écotones) entre milieux terrestres et aquatiques, elles présentent une très grande richesse biologique, tant pour la flore que pour la faune. Les berges jouent également un rôle majeur de corridor biologique pour les vertébrés et les invertébrés. L'anthropisation croissante de ces milieux conduit fréquemment à leur stabilisation avec des techniques de protection de berges. Ces techniques de protection sont nombreuses et variées. Certains ouvrages sont purement minéraux et uniquement constitués de béton ou d'enrochement, d'autres par contre sont entièrement constitués de matériaux vivants et biodégradables (boutures, géotextiles, pieux…). Enfin, certains ouvrages sont dits «mixtes» et associent matériaux minéraux (enrochements, grillages…) et vivants. Le type de matériaux et leurs conditions de mise en oeuvre vont influer sur les capacités d'accueil de la biodiversité de ces différents ouvrages.L'objectif de ce travail est de quantifier et d'analyser la biodiversité taxonomique et fonctionnelle de ces berges aménagées, dans la perspective de contribuer à l'amélioration du fonctionnement écologique de ces milieux et des services écosystémiques associés.Dans ce travail nous avons évalué les diversités taxonomiques et fonctionnelles des plantes vasculaires terrestres, des coléoptères aériens et des macroinvertébrés benthiques présents en pied de berge de plusieurs types d'aménagement de berge. Ces résultats ont fait l'objet d'une analyse comparative avec ceux des berges de référence subnaturelles à saulaies basses.Nous avons ainsi montré que les techniques issues du génie végétal engendraient des diversités taxonomiques et fonctionnelles, animales et végétales, significativement plus grandes que celles observées sur les aménagements issus du génie civil. D'autre part, la compétition interspécifique sur les aménagements issus du génie végétal limite le développement et l'invasion des espèces végétales néophytes. Enfin, la structure et le fonctionnement des communautés d'organismes terrestres et aquatiques sont largement dépendants de la technique d'aménagement et des conditions biotiques et abiotiques associées. / Riverbanks are interfaces (or ecotones) between terrestrial and aquatic areas, they have a great biodiversity for both flora and fauna. Riverbanks also contribute to the set up of the biological corridor for vertebrates and invertebrates migrations. The increasing human impact on these environments often leads to their stabilization using several bank protection techniques. These techniques are many and varied. Some techniques are purely mineral and only consist of concrete or rock; others consist entirely of organic or even living materials (Geotextiles, cuttings, woody stakes...). Finally, some works are identified as "mixed" and they combine mineral (stones, blocs...) and alive materials. The material constitution and their implementation will affect the biodiversity of each riverbank work.This study aims to quantify and analyze the taxonomic and functional biodiversity of the riverbank works in order to improve our understanding of the ecological functioning of these anthropogenic areas and associated ecosystem services.In this work, we surveyed taxonomic and functional diversities of vascular land plants, flying and ground beetles and benthic macroinvertebrates supported on each riverbank and according to bank management type. These results have been benchmarked with subnatural low willow stand banks taken as control banks.We show that techniques stemmed from bioengineering lead to significantly larger plant and animal, taxonomic and functional diversity, than those surveyed on riverbanks stemmed from civil engineering. On the other hand, interspecific competition on the bioengineering techniques limits the development and invasion of plant species neophytes. Finally, community structures and functioning of terrestrial and aquatic organisms are largely dependent on the riverbank technique and associated biotic and abiotic conditions.

The City of Winnipeg, located at the confluence of the Red and Assiniboine Rivers, has over 240 km of natural riverbank property. The increased frequency and magnitude of flooding along the Red and Assiniboine Rivers over the past decade appears to have influenced the number of slope failures along riverbank property, resulting in the loss of both public green space and privately owned land. The loss of private and public property adjacent to the river has led to the loss of valuable real estate and public parkland amenities. To ensure that riverbank property is preserved for future generations, the City of Winnipeg wants to increase the stability of certain reaches of publicly owned riverbank property along the Red and Assiniboine Rivers that are prone to slope movements. Extensive research has been conducted on slope stability problems in the Winnipeg area, but a transparent prioritization procedure for the remediation of riverbank stability problems has not existed. Therefore, a Riverbank Asset Management System (RAMS) was developed for publicly owned riverbank property to prioritize riverbank slope stability problems along the Red and Assiniboine Rivers. The RAMS provides the City of Winnipeg with a rational approach for determining risk levels for specific reaches of the Red and Assiniboine Rivers. The calculated risk levels allow the City to develop recommended response levels for slope stability remediation projects in a fiscally responsible manner with minimal personal and political influences. This system permits the City to facilitate timely and periodic reviews of priority sites as riverbank conditions and input parameters change. / May 2009

Hydropower is a more environmental friendly way of producing electric power than many other alternatives today. Though, the effects of constructing mega dams are much tangible for the local eco systems in addition to changing many people’s lives forever. In order to prevent floods, riverbank erosions or landslides, proper investigations of the environmental impact from dam constructions must be performed. One of the key parameters in such investigations is the flow discharge velocity. This master thesis treats experimental measurements and numerical simulations of the velocity downstream a model of Xiluodu dam. The Xiluodu dam is a mega dam under construction in China and will have a total capacity of 12 600 MW when completed. The model is in scale 1:100 and the experiments have been performed at Department of Hydraulic Engineering, Tsinghua University, Beijing, China. The velocity profile shows that the velocity in the middle of the river is larger than the velocity at the surface and near the riverbank. The comparison between the measured and the simulated velocities shows a difference of less than 20 percent in almost all points which can be considered as a good result. In those points where the difference is more than 20 percent, this is believed to be due to the position of these points. Some of them were located near a vortex and others very close to the bottom. This is a problem when sparsely measured topography in combination with linear interpolation makes the boundaries of the simulations incorrect. In order to perform better simulations, more densely topography data and better flow boundary conditions should be used. More measuring points of the velocity could also improve the result.

The City of Winnipeg, located at the confluence of the Red and Assiniboine Rivers, has over 240 km of natural riverbank property. The increased frequency and magnitude of flooding along the Red and Assiniboine Rivers over the past decade appears to have influenced the number of slope failures along riverbank property, resulting in the loss of both public green space and privately owned land. The loss of private and public property adjacent to the river has led to the loss of valuable real estate and public parkland amenities. To ensure that riverbank property is preserved for future generations, the City of Winnipeg wants to increase the stability of certain reaches of publicly owned riverbank property along the Red and Assiniboine Rivers that are prone to slope movements. Extensive research has been conducted on slope stability problems in the Winnipeg area, but a transparent prioritization procedure for the remediation of riverbank stability problems has not existed. Therefore, a Riverbank Asset Management System (RAMS) was developed for publicly owned riverbank property to prioritize riverbank slope stability problems along the Red and Assiniboine Rivers. The RAMS provides the City of Winnipeg with a rational approach for determining risk levels for specific reaches of the Red and Assiniboine Rivers. The calculated risk levels allow the City to develop recommended response levels for slope stability remediation projects in a fiscally responsible manner with minimal personal and political influences. This system permits the City to facilitate timely and periodic reviews of priority sites as riverbank conditions and input parameters change.

The City of Winnipeg, located at the confluence of the Red and Assiniboine Rivers, has over 240 km of natural riverbank property. The increased frequency and magnitude of flooding along the Red and Assiniboine Rivers over the past decade appears to have influenced the number of slope failures along riverbank property, resulting in the loss of both public green space and privately owned land. The loss of private and public property adjacent to the river has led to the loss of valuable real estate and public parkland amenities. To ensure that riverbank property is preserved for future generations, the City of Winnipeg wants to increase the stability of certain reaches of publicly owned riverbank property along the Red and Assiniboine Rivers that are prone to slope movements. Extensive research has been conducted on slope stability problems in the Winnipeg area, but a transparent prioritization procedure for the remediation of riverbank stability problems has not existed. Therefore, a Riverbank Asset Management System (RAMS) was developed for publicly owned riverbank property to prioritize riverbank slope stability problems along the Red and Assiniboine Rivers. The RAMS provides the City of Winnipeg with a rational approach for determining risk levels for specific reaches of the Red and Assiniboine Rivers. The calculated risk levels allow the City to develop recommended response levels for slope stability remediation projects in a fiscally responsible manner with minimal personal and political influences. This system permits the City to facilitate timely and periodic reviews of priority sites as riverbank conditions and input parameters change.

Elevated concentrations of mercury (Hg) in aquatic systems can be a threat to ecosystems and human health. Mercury-bearing sediment particles from eroding riverbanks can be an ongoing source of bioavailable Hg to aquatic ecosystems. Hyporheic zones in particular can be important sources of both inorganic and organic-complexed Hg, which can be rapidly transported to adjacent surface waters. The objective of this study was to investigate the release and treatment of dissolved and particle-bound Hg in water derived from the riverbank sediments of the South River, Virginia. The solid-phase forms of Hg in riverbank sediment samples were characterized by sequential extraction and synchrotron based techniques. The analyses suggest that 79-93% of Hg in the sediment samples is in the form of insoluble sulfides (βHgS metacinnabar); however significant masses of more-soluble Hg phases (0.4-33 μg/g) are also present. Simulated erosion events resulted in elevated concentrations of Hg in the river water up to 80 μg/L. There was no correlation between the mass of water-soluble Hg in the sediment and the concentrations of Hg released in the river water following sediment suspension. Column transport experiments were conducted to assess Hg release from the sediment under water:sediment ratios typical of those that might occur at the bottom or in the banks of the river. Concentrations of Hg in the 0.45 μm-filtered fraction of the effluent varied from 0.15 μg/L for samples collected from the base of the riverbank to 8 μg/L for samples collected from the top of the riverbank. Filter size-fractionation of water column effluent suggested approximately 50% of the leached Hg was present in the dissolved phase, with the remainder in particulate form. Riverbank sediments were amended with various types of reactive material including complexing agents, reductants and charcoals. Batch experiments indicate that the mass of Hg released from the sediment could be lessened by 64-99% with the addition of reactive media, and that aerating and re-wetting the sediment amendments resulted in equal or greater removal of Hg from the water. The greatest removal of Hg was observed when more amendment was added to the sediment, however the greatest Hg uptake capacity (Hg captured per mass of material) was observed for the lowest doses of reactive media. The Hg uptake capacities ranged from 35-500 ng/g and were greatest for treatment of water with elevated concentrations of Hg. The Hg uptake capacities were a function of the Hg concentrations in the untreated water, and were generally lower relative to values reported in the literature. Column studies were used to simulate the flow of river water containing elevated concentrations of Hg through a reactive zone containing a charred hardwood material. The concentration of filtered Hg was < 120 ng/L for treated effluent from columns, resulting in > 98% removal of Hg from the water. Assuming that the majority of removal occurred within the initial 2-3 cm along the length of the column, the calculated uptake of Hg2+ ranged from 1.2-7.7 μg/g. The uptake capacity for charred hardwood material was much greater for the column experiments relative to the batch experiments, suggesting that the uptake capacity is limited by Hg loading. The chemical composition of the treated column effluent was similar to the South River water, and suggests the material did not add or remove significant constituents during the course of these experiments.

Elevated concentrations of mercury (Hg) in aquatic systems can be a threat to ecosystems and human health. Mercury-bearing sediment particles from eroding riverbanks can be an ongoing source of bioavailable Hg to aquatic ecosystems. Hyporheic zones in particular can be important sources of both inorganic and organic-complexed Hg, which can be rapidly transported to adjacent surface waters. The objective of this study was to investigate the release and treatment of dissolved and particle-bound Hg in water derived from the riverbank sediments of the South River, Virginia. The solid-phase forms of Hg in riverbank sediment samples were characterized by sequential extraction and synchrotron based techniques. The analyses suggest that 79-93% of Hg in the sediment samples is in the form of insoluble sulfides (βHgS metacinnabar); however significant masses of more-soluble Hg phases (0.4-33 μg/g) are also present. Simulated erosion events resulted in elevated concentrations of Hg in the river water up to 80 μg/L. There was no correlation between the mass of water-soluble Hg in the sediment and the concentrations of Hg released in the river water following sediment suspension. Column transport experiments were conducted to assess Hg release from the sediment under water:sediment ratios typical of those that might occur at the bottom or in the banks of the river. Concentrations of Hg in the 0.45 μm-filtered fraction of the effluent varied from 0.15 μg/L for samples collected from the base of the riverbank to 8 μg/L for samples collected from the top of the riverbank. Filter size-fractionation of water column effluent suggested approximately 50% of the leached Hg was present in the dissolved phase, with the remainder in particulate form. Riverbank sediments were amended with various types of reactive material including complexing agents, reductants and charcoals. Batch experiments indicate that the mass of Hg released from the sediment could be lessened by 64-99% with the addition of reactive media, and that aerating and re-wetting the sediment amendments resulted in equal or greater removal of Hg from the water. The greatest removal of Hg was observed when more amendment was added to the sediment, however the greatest Hg uptake capacity (Hg captured per mass of material) was observed for the lowest doses of reactive media. The Hg uptake capacities ranged from 35-500 ng/g and were greatest for treatment of water with elevated concentrations of Hg. The Hg uptake capacities were a function of the Hg concentrations in the untreated water, and were generally lower relative to values reported in the literature. Column studies were used to simulate the flow of river water containing elevated concentrations of Hg through a reactive zone containing a charred hardwood material. The concentration of filtered Hg was < 120 ng/L for treated effluent from columns, resulting in > 98% removal of Hg from the water. Assuming that the majority of removal occurred within the initial 2-3 cm along the length of the column, the calculated uptake of Hg2+ ranged from 1.2-7.7 μg/g. The uptake capacity for charred hardwood material was much greater for the column experiments relative to the batch experiments, suggesting that the uptake capacity is limited by Hg loading. The chemical composition of the treated column effluent was similar to the South River water, and suggests the material did not add or remove significant constituents during the course of these experiments.

Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2006. / Title from first page of PDF document. Includes bibliographical references (p. 33-35).