Les contours théoriques en hydrologie, hydraulique et les outils de calcul correspondants sont largement développés et utilisés dans le monde. Cependant en parallèle, des problématiques importantes surviennent pendant les crises sans pouvoir être résolues et des solutions développées peinent à être implémentées. En plus, le changement climatique ne va pas faciliter les choses. Pour noircir le tableau, les moyens économiques locaux en France ne vont pas augmenter pour aider les communes à s’attaquer au problème. L’objectif de cette thèse est de conduire une investigation des moyens à disposition pour améliorer notre connaissance locale des concepts en lien avec le pluvial pour permettre une modélisation efficiente. La méthodologie proposée est composée de trois étapes évolutives incluant : 1. Une analyse approfondie des données topographiques locales ; 2. L’évaluation des interactions entre les écoulements de surface et le souterrain ; 3.Une approche intégrée permettant de modéliser les inondations générées par la pluie en zone urbanisée. Les résultats de l’étape 1 montrent que la donnée topographique est essentielle pour la définition des chemins d’écoulement et impactent significativement les résultats de modélisation hydrauliques. Ceci conduit à l’étape 2 lors de laquelle on observe que les débordements provenant du réseau souterrain contribuent à l’inondation mais seulement en partie. Les volumes d’inondations générés par le ruissellement de surface devraient être inclus dans les modèles d’inondation. L’étape 3 présente une configuration possible de modèle intégré permettant de mieux représenter les processus réels en jeu. / Theoretical background about hydrology, hydraulics and computational tools and methods are widely developed and worldwide used. In the same time however, important issues during flood crisis are not solved and practical solutions take time to be implemented. On top of that, ongoing climatic change will not make things easier and intense events will increase in frequency. To worsen the picture, local economic means in France will not increase to help municipalities and local communities to tackle the issue. The objective of this thesis is to investigate on the available ways to improve our local knowledge of stormwater related concepts to allow an efficient modelling. The proposed methodology consists in a three-step-approach including: 1. A thorough analysis of local topography data; 2. The assessment of sewer-surface interactions; 3. An integrated approach to model pluvial flood in urban areas. The results of Step 1 show that topography data is essential in flow path definition and significantly impacts hydraulic modelling results. This leads to Step 2 where it is seen that sewer overflow is one aspect of urban flood issues but represents only part of flood sources. Overland flow generated by runoff should be included in flood models. Then Step 3 presents that integrated urban pluvial modelling is possible with existing tools and can represent the real processes better. This proposed modelling approach should not be disconnected from the reality of stormwater management practical aspects and current constraints. It is shown how complementary actions can be taken to enrich local knowledge and memory thus allowing a more efficient and wiser modelling process.

Urbanization is continuously growing all over the world. Both developing and developed countries encourage rapid expansion for increased growth and production. However, urbanization in combination with climate change can lead to higher chances of extreme flood events. Mankind always settled around rivers and floodplains that are naturally more flood prone areas, making stormwater modeling and urban planning indispensable for safety and reduction of flood risk.Until now many important studies have been conducted on the dangers of living in floodplains of urbanized cities, but most of them are about developing countries such as Bangladesh or Vietnam, leaving a noticeable gap in the developed world. However, all these researches share one thing in common as they do not take into account the interactions between water and society by ignoring the constantly changing human factor.Socio-hydrology is a new branch of hydrology closely related to Integrated Water Resource Management (IWRM) that tries to explore this dynamic relationship. This study explores the historical evolution of a highly urbanized industrial city in Finland and attempts to understand both the human and engineering effects of urbanization. The city of Pori is the most flood prone area in Finland, which makes for an important study that will yield important results and possible recommendations for future research, while for the first time incorporating socio-hydrology, the human factor and flood risk in a major European city.This is an empirical project with data collected from various different sources put all together for the first time that could change the perceptions of both inhabitants and scientists and be the basis for a more thorough, modeling based research in the future. The research question of this dissertation is how socio-hydrological dynamics have affected flood risk changes over the past decades in the city of Pori. / Urbaniseringen växer fortlöpande över hela världen. Både industriländer och utvecklingsländer befrämjar snabb expansion för ökad tillväxt och produktion. Dock leder urbanisering i kombination med klimatförändring till högre risk för extrema översvämningar. Människor har i alla tider bosatt sig runt vattendrag och flodslätter som naturligt är mer benägna att översvämmas, något som gör att dagvattenhantering och stadsplanering är absolut nödvändigt för ökad säkerhet och reducerad översvämningsrisk.Fram tills nu har många viktiga studier genomförts som behandlar farorna för människor bosatta i urbaniserade städer intill flodslätter, men de flesta av dem har utgått från utvecklingsländer som Bangladesh eller Vietnam, något som lett till en märkbar avsaknad av information gällande industri-länder. Gemensamt för dessa studier är dock att de ignorerar den ständigt föränderliga mänskliga faktorn och på så sätt inte tar i beaktning interaktioner mellan vatten och samhälle.Socio-hydrologi är en ny gren inom hydrologi som är nära besläktad med Integrerad Vattenresurs-förvaltning och som försöker utforska detta dynamiska samspel. Denna studie undersöker den historiska utvecklingen av en starkt urbaniserad industristad i Finland och försöker tolka de mänskliga och tekniska effekterna av urbanisering. Staden Pori (Björneborg på svenska) är den mest översvämningsbenägna platsen i Finland, vilket gör denna studie till ett viktigt arbete för att ta fram betydelsefulla resultat och eventuella rekommendationer för framtida forskning. Dessutom inkorporeras socio-hydrologi, den mänskliga faktorn och översvämningsrisk för första gången i forskning gällande en större europeisk stad.Detta är ett empiriskt projekt med data insamlat från olika källor som sammanställts för första gången och som kan förändra både invånares och forskares synsätt, samt vara en grund för mer utförlig och modellbaserad forskning i framtiden. Frågan som denna avhandling försöker besvara är hur socio-hydrologisk dynamik har påverkat förändringar av översvämningsrisker i staden Pori i Finland över de senaste årtiondena.

The Stephens Creek Watershed in southwest Portland, Oregon was chosen by the city as a pilot project for urban stream restoration efforts, and the infiltration of stormwater was identified as a potential restoration strategy. The Stephens Creek Watershed has historically been known to be unstable during high precipitation events (Burns, 1996), and the need to address the response of slope stability to anthropogenically-driven changing groundwater conditions is the focus of this study. Airborne light detection and ranging (LiDAR) and geotechnical data from the City of Portland were employed to create a high resolution (0.84 m2) physics-based probabilistic slope stability model for this watershed, using the map-based probabilistic infinite slope analysis program PISA-m (Haneberg, 2007). Best and worst case models were run using fully dry and fully saturated soil conditions, respectively. Model results indicate that 96.3% of the watershed area had a probability [less than or equal to] 0.25 that the slope factor of safety (FOS) was [less than or equal to] 1 for fully dry conditions, compared to 76.4% for fully saturated conditions. Areas that had a probability [greater than or equal to] 0.25 that the slope factor of safety (FOS) was [less than or equal to] 1 were found to occur mainly along cut/fill slopes as well as within the deeply incised canyons of Stephens Creek and its tributaries. An infiltration avoidance map was derived to define areas that appear to be unsuitable for infiltration. Based on these results, it is recommended that stormwater continues to be directed to existing sewer infrastructure and that the "storm water disconnect" restoration approach not be used by the city.

In vielen Städten erfordern fortschreitende Urbanisierung und Klimaerwärmung ein besseres Verständnis des urbanen Wasserkreislaufes zur Entwicklung nachhaltiger Wassernutzungskonzepte. Jedoch erschwert die Komplexität urbaner Wasserflüsse die Nutzung hydrologischer Tracer. In dieser Arbeit werden stabile Isotope des Wassers, hydrochemische und -klimatische Daten genutzt, um die Wasserverteilung und -speicherung in Berlin in den Trockenjahren 2018–2020 zu untersuchen. Auf kleinräumiger Skala wurden Unterschiede bei Evapotranspiration, unterirdischen Fließwegen und Wasserspeicherung unter urbanen Grasflächen, Sträuchern und Bäumen deutlich. Im peri-urbanen Fluss Erpe erschwerte die geringe Variabilität von Abfluss- und Isotopendynamiken die Bestimmung von Verweilzeiten und Mischprozessen. Während warmer, trockener Sommer führte ein hoher Klarwasseranteil zu einer Verschlechterung der Wasserqualität. Auf der stadtweiten Skala wurde der Einfluss von Grundwasser, Niederschlag und Abwasser auf verschiedene Flüsse untersucht. Große Variabilität der Isotopendynamiken wurde in Einzugsgebieten mit Flächenversiegelung und Regenwassereinleitung beobachtet. Die Anreicherung schwerer Isotope in Spree und Havel im Sommer und Herbst verdeutlichte den Einfluss von großskaligen Klimadynamiken und Verdunstung im stromaufwärts gelegenen Einzugsgebiet. Ein nachhaltiges Management urbaner Grünflächen sowie die Speicherung von Regenwasser können dazu beitragen, den Einfluss von Klimaänderungen auf Berlins Wasserressourcen auf lokaler Ebene abzumindern. Jedoch werden großskalige Nutzungskonzepte in den Einzugsgebieten der Spree und Havel benötigt, um Wasserverluste zu minimieren und Abflussraten aufrecht zu erhalten. Weiterführende isotopenbasierte Studien haben großes Potential, das Verständnis von Wasseralter, Abflussentstehung, Verdunstung und langfristigen Dürrefolgen, sowie der Übertragbarkeit der Erkenntnisse auf andere Metropolenregionen, weiter zu verbessern. / In urban areas, progressing urbanisation and climate warming call for a comprehensive understanding of urban water cycling to establish sustainable water management strategies. However, the complexity of urban water fluxes complicates the application of hydrological tracers. This thesis used stable isotopes of water, combined with hydrochemical and climatic data, to characterise water partitioning and storage in Berlin, Germany, during the exceptionally warm and dry 2018–2020 period. At the plot-scale, differences in evapotranspiration, subsurface flow paths and storage under urban grassland, shrub and trees were evident. In the peri-urban river Erpe, low variability in discharge and isotopic dynamics limited the applicability of transit time and end member mixing approaches. During warm and dry summers, high contributions of treated wastewater effluents caused a deterioration of water quality. At the city-scale, contributions of groundwater, storm runoff and effluents to different local streams were studied. Isotope dynamics were most variable in catchments with high levels of imperviousness and connectivity to storm drains. In the Spree and Havel rivers, the isotopic enrichment in summer and autumn reflected the impact of large-scale climate dynamics and evaporative losses in the upstream catchment. To mitigate climate change impacts on Berlin’s water resources in the future, the sustainable management of urban green spaces and better capturing of urban rainfall may limit water consumption at the local scale. However, maintaining discharge in the Spree and Havel rivers during warm and dry periods will require catchment-scale management practices that limit water consumption and losses in upstream areas. Future isotope-based research in urban areas has great potential to improve the understanding of urban water ages, source contributions to urban streamflow, evaporation and long-term drought recovery, as well as upscaling the results to other metropolitan areas.

This project proposes a new urban aquifer strategy that utilizes stormwater to create a cascading plaza and an improved 'great street' in Washington DC. A system of urban aquifers is developed beneath the surface of the street, perched atop the compacted, impermeable soils below. This set of aquifers prevents stormwater from entering the existing combined sewer and allows trees to draw water from this new groundwater source and develop expansive root systems. On the surface, stormwater flows through interconnected planters where it irrigates and is filtered by vegetation before infiltrating to recharge the aquifer. At Cascade Plaza, sloping topography intersects the aquifer, and the new groundwater seeps out of the plaza steps, turning them into a miniature cascade, by gravity and water pressure alone. It collects in a web of runnels, pools at the lowest point, and overflows in high water, mysteriously disappearing below ground again to fill an underground reservoir. In this unique ecological system, water flows both above and below ground to mitigate excess stormwater and make the street and plaza more beautiful. / Master of Landscape Architecture

O objetivo deste trabalho foi propor, entre os índices já existentes, um índice que avalie a qualidade da cobertura vegetal em relação à sua função ecológica, no meio urbano. Para a composição deste índice, compararam-se os métodos de amostragem aleatória simples e de amostragem estratificada de inventários da arborização de calçadas com o censo, com a finalidade de se escolher o melhor método de levantamento quali-quantitativo para árvores de calçada. Determinou-se o número de árvores por quilômetro, número total de árvores, Índice de Diversidade de Shannon (IDS) para árvores de calçada. Foram calculados o Índice de Espaços Livres de Uso Público (IELUP), a Porcentagem de Espaços Livres de Uso Público (PELUP), o Índice de Cobertura Vegetal em Áreas Urbanas (ICVAU) e o Índice de Verde por Habitante (IVH). Foram utilizadas planta baixa digital, fotografia aérea e videografia para mensurar as áreas ocupadas pela vegetação. A unidade de paisagem escolhida para estudo foi o bairro Santa Cecília em Piracicaba, Estado de São Paulo, Brasil, nos anos de 2000 a 2003. O levantamento amostral qualitativo das árvores de calçada foi feito por amostragem aleatória simples, escolhido, no trabalho, como o melhor método para inventariar árvores de rua. Considerando o ano de 2003, para a proposição do índice, os resultados obtidos foram: a) o IELUP variou de 11,42 a 41,62m2/hab (videografia); b) o PELUP variou de 1,52% a 2,89%; c) o ICVAU foi de 25,76m2 (forração + cobertura arbórea) e de 16,48 m2 (cobertura arbórea); d) o IVH foi de 101,96m2/hab (forração + cobertura arbórea) e de 65,21m2/hab (cobertura arbórea). Para a avaliação de espaços verdes urbanos foi feita discussão em função de obter-se um chamado "Índice de Qualidade do Espaço Verde Urbano" (IQEVU), particularizado para a função ecológica, então denominado "Índice de Qualidade do Espaço Verde Urbano com Função Ecológica" (IQEVUe). Os parâmetros para avaliação deste último índice foram: sombreamento, para árvores de calçadas; hidrologia, fixação de Carbono e influência de temperatura, para todos os espaços verdes. O IQEVUe mostrou-se adequado e coerente para mensurar os benefícios da vegetação em áreas urbanas, fornecendo subsídios para o planejamento e o manejo de cidades. / The aim of this work was to propose a new index, amongst other already known, that evaluates the quality of green coverage in relation to its ecological role in urban environment. To elaborate this index, simple random and stratified random sampling were compared with the census, in order to assess the best qualitative and quantitative method to do the tree inventory. A survey of sidewalk arborisation, as well as trees per kilometre, total number of trees and the Shannon Diversity Index (IDS) of sidewalk trees were evaluated. Amongst the studied indexes were the Index of Open Spaces for Public Use (IELUP), Percentage of Open Spaces for Public Use (PELUP), Index of Green Coverage for Urban Areas (ICVAU) and Index of Green per Inhabitant (IVH), by means of digital plan, aerial photography and videography for the areas covered by vegetation measurement. Santa Cecilia District in Piracicaba City, Sao Paulo State, Brazil, was the object of study from 2000 to 2003. The qualitative sampling survey of trees was carried out by simple random sampling, as found to be the most adequate to survey sidewalk trees. Data obtained for 2003, the year chosen to propose the new index, were: a) IELUP varied from 11.42 to 41.62m2/inhab, using videography; b) PELUP varied from 1.52% to 2.89%; c) ICVAU was 25.76m2 (coverage + tree canopy) and 16.48m2 ( tree canopy ); d) IVH consisted of 101.96m2/hab (coverage + tree canopy) and 65.21m2/inhab (tree canopy). The index for the evaluation of green spaces, so named "Index for Quality of Green Urban Space" (IQEVU) was one of the subsidies to study and propose the "Index for Quality of Green Urban Space with Ecological Role" (IQEVUe). The parameters for evaluation of such index were the shading from sidewalk trees; hydrology, Carbon sequestration and temperature influence for all green space. In this study, the proposed IQEVUe seems to be adequate and coherent as an evaluation method for the benefits of urban vegetation, providing subsidies for the planning and management of cities.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / The recently- created Arizona Groundwater Management Study Commission is mandated to propose a reform of Arizona's groundwater laws. A number of issues must be addressed by this Commission in order to deal with urban problems with present groundwater law. These include: a comprehensive set of regulations on groundwater use to enhance the public interest and benefit in scarce groundwater resources; a permanent mechanism to permit transfer of water rights away from specific parcels of land; an effective system of management which considers differing types of water problems in various parts of the state; a method of quantifying existing rights and measuring use of groundwater; an extraction tax to recognize public costs associated with groundwater mining and the need for replenishment; a reevaluation of existing preferences and subsidies which encourage the mining of groundwater. Failure by Arizona to reform its groundwater laws threatens future funding for the Central Arizona Project and increases the possibility of federal intervention in state water management.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / The relationships between the separate disciplines of hydrology and law are analysed in this study into how water law and its strictures may impose upon the development of urban runoff in the metropolitan Tucson area. Brief descriptions of the doctrine of appropriation, diffuse surface waters and developed waters are presented to illustrate the complexities of the problem of urban runoff development. It is suggested that planners must not only be aware of the legal issues involved but also must understand the philosophy and principles of water law.

Natural vegetation has been converted to land uses, such as agriculture, commercial forestry and urban use, to meet increasing human demands for food, fuel and shelter. These land use changes modify the surface conditions of an area, resulting in changes in hydrological responses. Urban land use, in particular, has a significant impact on catchment hydrology as a result of the increased impervious areas such as concrete, tar and roofs. To assess the future hydrological impacts of urban land use, the scale and location of future urban areas must be considered. The objective of this study was to assess the hydrological responses to future urban growth in the Mgeni catchment, South Africa. An urban growth model was used to generate scenarios of plausible future urban growth and these scenarios were modelled using a hydrological model to determine the hydrological responses to urban growth. The plausible future urban growth in the Mgeni catchment was modelled using the SLEUTH Urban Growth model (SLEUTH). The SLEUTH acronym stands for the input layers required for the model viz. Slope, Land use, Excluded areas, Urban Extent, Transport routes and Hillshade. SLEUTH is able to provide the scale and location of future urban growth required to assess the hydrological impacts of future urban growth. The data requirements and modelling procedure for SLEUTH is relatively simply and therefore it is well suited to a South African context. SLEUTH was calibrated and applied to the Mgeni catchment to project future urban land use. When assessing the 95-100% probability class, the results revealed that the Henley, Pietermaritzburg and Durban areas would experience the highest urban growth in the Mgeni catchment by the year 2050. The outputs of the SLEUTH Model for the Mgeni catchment showed a number of similarities to another application of SLEUTH in Cape Town. These similarities indicate the SLEUTH performs in a similar way for the two South African cities. Therefore, it was concluded that the SLEUTH Model is suitable to account for urban growth in the Mgeni catchment, as required for use in hydrological impact studies. The hydrological responses to urban growth in the Mgeni catchment were assessed using the ACRU model. The scenarios of plausible future urban growth generated by SLEUTH were overlaid with current land cover layers to generate maps of plausible future urban land use. The results showed extensive urban growth of >95% probability occurring in the Midmar, Albert Falls, Henley, Pietermaritzburg, Table Mountain, Inanda and Durban Water Management Areas (WMAs) by 2050. Increases in mean annual streamflows were observed in many of these areas; however the Henley, Pietermaritzburg and Table Mountain WMAs were shown to have greater increases in mean annual streamflow than the other areas that showed similar increases in urban growth, thus indicating that these WMAs could be particularly responsive to urban growth in the future. Furthermore, the results showed that the type of urban land use is important in determining the hydrological responses of urban land use, as the imperviousness differs between the different urban land uses. Streamflow responses were shown to be influenced by the scale and location of urban growth in the Mgeni catchment and specific areas, such as the WMAs along the Msunduzi River, were identified as potentially responsive to urban growth. Summer streamflows were indicated as being more responsive to urban land use changes than winter streamflows and increases in streamflows due to urban growth start to over-ride the impacts of other land uses which have substantial impacts on hydrological responses such as commercial forestry, and commercial sugarcane by 2050, whereas in other areas increases were mitigated by the presence of major dams. Lastly, it was shown that the type of urban land use, such as built up urban areas when compared to informal urban areas for example, have a significant impact on streamflow responses. These results are useful as they can be used to inform both water resources planning as well as urban planning to ensure that South Africa’s valuable water resources are protected. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

O objetivo deste trabalho foi propor, entre os índices já existentes, um índice que avalie a qualidade da cobertura vegetal em relação à sua função ecológica, no meio urbano. Para a composição deste índice, compararam-se os métodos de amostragem aleatória simples e de amostragem estratificada de inventários da arborização de calçadas com o censo, com a finalidade de se escolher o melhor método de levantamento quali-quantitativo para árvores de calçada. Determinou-se o número de árvores por quilômetro, número total de árvores, Índice de Diversidade de Shannon (IDS) para árvores de calçada. Foram calculados o Índice de Espaços Livres de Uso Público (IELUP), a Porcentagem de Espaços Livres de Uso Público (PELUP), o Índice de Cobertura Vegetal em Áreas Urbanas (ICVAU) e o Índice de Verde por Habitante (IVH). Foram utilizadas planta baixa digital, fotografia aérea e videografia para mensurar as áreas ocupadas pela vegetação. A unidade de paisagem escolhida para estudo foi o bairro Santa Cecília em Piracicaba, Estado de São Paulo, Brasil, nos anos de 2000 a 2003. O levantamento amostral qualitativo das árvores de calçada foi feito por amostragem aleatória simples, escolhido, no trabalho, como o melhor método para inventariar árvores de rua. Considerando o ano de 2003, para a proposição do índice, os resultados obtidos foram: a) o IELUP variou de 11,42 a 41,62m2/hab (videografia); b) o PELUP variou de 1,52% a 2,89%; c) o ICVAU foi de 25,76m2 (forração + cobertura arbórea) e de 16,48 m2 (cobertura arbórea); d) o IVH foi de 101,96m2/hab (forração + cobertura arbórea) e de 65,21m2/hab (cobertura arbórea). Para a avaliação de espaços verdes urbanos foi feita discussão em função de obter-se um chamado “Índice de Qualidade do Espaço Verde Urbano” (IQEVU), particularizado para a função ecológica, então denominado “Índice de Qualidade do Espaço Verde Urbano com Função Ecológica” (IQEVUe). Os parâmetros para avaliação deste último índice foram: sombreamento, para árvores de calçadas; hidrologia, fixação de Carbono e influência de temperatura, para todos os espaços verdes. O IQEVUe mostrou-se adequado e coerente para mensurar os benefícios da vegetação em áreas urbanas, fornecendo subsídios para o planejamento e o manejo de cidades. / The aim of this work was to propose a new index, amongst other already known, that evaluates the quality of green coverage in relation to its ecological role in urban environment. To elaborate this index, simple random and stratified random sampling were compared with the census, in order to assess the best qualitative and quantitative method to do the tree inventory. A survey of sidewalk arborisation, as well as trees per kilometre, total number of trees and the Shannon Diversity Index (IDS) of sidewalk trees were evaluated. Amongst the studied indexes were the Index of Open Spaces for Public Use (IELUP), Percentage of Open Spaces for Public Use (PELUP), Index of Green Coverage for Urban Areas (ICVAU) and Index of Green per Inhabitant (IVH), by means of digital plan, aerial photography and videography for the areas covered by vegetation measurement. Santa Cecilia District in Piracicaba City, Sao Paulo State, Brazil, was the object of study from 2000 to 2003. The qualitative sampling survey of trees was carried out by simple random sampling, as found to be the most adequate to survey sidewalk trees. Data obtained for 2003, the year chosen to propose the new index, were: a) IELUP varied from 11.42 to 41.62m2/inhab, using videography; b) PELUP varied from 1.52% to 2.89%; c) ICVAU was 25.76m2 (coverage + tree canopy) and 16.48m2 ( tree canopy ); d) IVH consisted of 101.96m2/hab (coverage + tree canopy) and 65.21m2/inhab (tree canopy). The index for the evaluation of green spaces, so named “Index for Quality of Green Urban Space” (IQEVU) was one of the subsidies to study and propose the “Index for Quality of Green Urban Space with Ecological Role” (IQEVUe). The parameters for evaluation of such index were the shading from sidewalk trees; hydrology, Carbon sequestration and temperature influence for all green space. In this study, the proposed IQEVUe seems to be adequate and coherent as an evaluation method for the benefits of urban vegetation, providing subsidies for the planning and management of cities.