• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 258
  • 93
  • 46
  • 24
  • 19
  • 11
  • 4
  • 1
  • 1
  • Tagged with
  • 609
  • 290
  • 188
  • 177
  • 162
  • 152
  • 124
  • 98
  • 69
  • 69
  • 67
  • 66
  • 60
  • 56
  • 51
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
481

En jämförelse mellan gröna-, metall- och gråa tak för ett oisolerat parkeringshus utifrån dess olika temperaturer och dagvattenhantering

Andersson, Emelie, Aziz, Shniar January 2019 (has links)
Since climate change increases and changes constantly, it contributes to higher average temperatures, ice melting and has a great impact on our ecosystem. This will then lead to a warmer climate, which means increased precipitation and milder winters. One of the reasons to climate change is urbanization, meaning people moving to the cities. To succeed in changing the climate, international cooperation and common goals are required. At the northern part of Brynäs, in the municipality of Gävle, work is currently in progress around the area where the factory of Läkerol was once standing. The area continues to be rebuilt and the outcome will eventually be called Godisfabriken. There, amongst other, a car park will be built for the newly built homes. The aim of this study is to compare metal roofs, grey concrete roofs and green roofs within the two aspects of stormwater management and temperature. Then analyse which alternative of these three roofs would be most advantageous for the car park of Godisfabriken.   The focused roofs are green, metal and concrete. A green roof is when it's completely or partly covered by a layer of vegetation and metal roofs are different sheet roofs with steel and aluminium-zinc. Grey roofs are made of concrete which works as both floor and ceiling. A building's roof affects which air temperature the surroundings has with its slope, vegetation and surrounding buildings. Another problem with urbanization and a warmer climate is stormwater management, which means rain and melted snow from roofs, parking areas and other hard surfaces.   The method includes a literature study and calculations. The literature study gave research on temperature for all roofs as well as stormwater management for green roofs. Calculations were made for stormwater management and temperature with its flow, absorption, reflectance and heat transfer.   The literature study and the calculations showed that green roofs have a high SRI value of 80 while the remaining roof is at around 40. The higher SRI, the lower surface temperatures on the material. This is proven in both methods when green roofs according to the literature study received a maximum surface temperature of 38 °C and 48 °C. According to the literature study green roofs can preserve more than 50 % of the rainwater. They also had a water flow rate of 1.97 l/s, which is less than half of what the metal roof got in the calculations. Since green roofs had both low air and surface temperatures, as well as longer drainage times and most absorbed water, green roofs are a more suitable choice than metal and grey concrete. / Eftersom klimatförändringarna förändras och konstant ökar bidrar det till en högre medeltemperatur, att isen smälter och att ekosystemet påverkas. Detta kommer då leda till ett varmare klimat vilket medför ökad nederbörd och mildare vintrar. En av orsakerna är urbanisering vilket betyder att människor flyttar till städer. För att lyckas förändra klimatet krävs internationellt samarbete och gemensamma mål.   Vid norra Brynäs i Gävle kommun pågår just nu arbete runt området där Läkerolfabriken en gång stod. Gamla Läkerolområdet kommer slutligen bli Godisfabriken. Där kommer det uppföras ett parkeringshus till det nybyggda bostäderna. Syftet med denna studie är att jämföra metalltak, gråa betongtak och gröna tak inom de två aspekterna dagvattenhantering och temperatur, därefter analysera vilket alternativ av dessa tre tak som skulle vara mest fördelaktigt för Godisfabrikens parkeringshus.   De fokuserade taken var grönt-, metall- och betong tak. Ett grönt tak är då taket är helt eller delvis täckt av ett lager vegetation. Metalltak är olika plåttak med stål och aluminium-zink, gråa tak syftar på betongbjälklag som fungerar både som golv och tak. En byggnads tak påverkar vilken lufttemperatur omgivningen har, även takets lutning samt växtlighet och byggnaderna runt om. Ett annat problem med urbanisering och varmare klimat är dagvattenhanteringen, vilket innebär regn- och smältvatten från bland annat tak, parkeringsytor och andra hårdgjorda ytor.   Metoden innefattar en litteraturstudie samt beräkningar. Litteraturstudien gav forskning om temperatur för samtliga tak samt dagvattenhantering för gröna tak. Beräkningar genomfördes för dagvattenhantering och temperatur med dess flöde, absorption, reflektans och värmeöverföring.   Litteraturstudien och beräkningarna visade att gröna tak har ett högt SRI (Solar Reflectance Index) värde på 80 medan resterande tak låg på runt 40. Ju högre SRI desto lägre yttemperaturer på materialet. Detta bevisas i båda metodvalen då gröna tak enligt litteraturstudie fick en maximal yttemperatur på 38 °C och 48 °C enligt beräkningarna. De hade även ett dagvattenflöde på 1,97 l/s, vilket är mindre än hälften av vad metalltaken på 4,93 l/s fick vid beräkningarna och kan enligt litteraturstudien bevara mer än 50 % av regnvattnet. Då gröna tak hade både låga luft- och yttemperaturer samt längre avrinningstid och mest absorberat vatten visar det att gröna tak är ett mer lämpligt val än metall- och gråa betongtak.
482

Biorretenção: tecnologia ambiental urbana para manejo das águas de chuva / Bioretention urban environmental technology for stormwater management

Moura, Newton Celio Becker de 10 March 2014 (has links)
Em caráter experimental, a tese examina o desempenho de sistemas de biorretenção na mitigação da poluição difusa ocasionada pelas águas de chuva. A avaliação dessa tecnologia ambiental urbana partiu da construção de um modelo de manejo dos escoamentos pluviais, utilizando uma matriz orgânica composta por vegetação, solo e agregados para retenção e tratamento inicial localizados. O protótipo, em escala 1:1, implementado na Cidade Universitária Armando Salles de Oliveira (CUASO-USP), São Paulo, SP, é composto por dois canteiros isolados entre si, que recebem as vazões através da sarjeta na via adjacente. Com preenchimentos iguais, os canteiros receberam coberturas vegetais distintas: gramado (G), com uma única espécie de gramínia, e jardim (J), com forrações, herbáceas e arbustos diversos, predominantemente nativos. O experimento foi monitorado por um ano, entre março de 2012 e março de 2013, quando foram coletados os dados referentes ao seu funcionamento e eficiência em sete eventos chuvosos paulistanos. A compilação dessas informações permitiu a análise comparativa da qualidade da água dos escoamentos antes e depois da passagem pelos canteiros. Com recursos da FUNDEP, FCTH e LabVERDE, a pesquisa interdepartamental e interdisciplinar, desenvolvida numa cooperação entre a FAU-USP e a Escola Politécnica-USP, busca oferecer respostas às hipóteses com que trabalha a Arquitetura da Paisagem ao propor soluções naturalizadas de manejo dos escoamentos pluviais em complementação às técnicas convencionais atualmente empregadas nas cidades brasileiras, tomando a cidade de São Paulo como cenário. Como efeito do processo histórico de canalização do seu patrimônio hídrico, ocupação das áreas de várzea e impermeabilização, a população paulistana e da RMSP tem sofrido com enchentes que se agravam com o crescimento urbano e com a intensificação das chuvas. As soluções imediatistas para essa situação crítica seguem a práxis das obras convencionais de engenharia, que segregam a drenagem urbana dos processos ecológicos e hidrológicos e não contribuem para melhoria da qualidade ambiental dos escoamentos antes de destiná-los aos corpos hídricos superficiais, o que agrava o quadro generalizado de poluição dos rios e córregos urbanos. Os resultados do experimento prático atestam o desempenho da biorretenção na mitigação da poluição difusa, com reduções médias das cargas poluidoras acumuladas de 89,94% para o gramado e 95,49% para o jardim, que foi comprovadamente mais eficiente. Aliados ao estudo de tipologias paisagísticas já utilizadas com sucesso em outras cidades do mundo, esses resultados poderão corroborar o processo de transição na infraestrutura de São Paulo, respaldando tecnicamente e cientificamente as soluções investigadas de manejo das águas de chuva através da biorretenção no tratamento dos espaços abertos e na conformação de uma Infraestrutura Verde na cidade. / This thesis experimentally assesses the performance of bioretention systems in mitigating nonpoint-source pollution caused by runoff. A 1:1 scale experiment of a stormwater management facility was built in USP Campus based in São Paulo, SP. This prototype has been evaluated for one year, since March 2012, over its technical efficiency to improve water quality by analyzing runoff samples collected in its inlet and outlet. Combining landscape architecture and hydraulic engineering knowledge, this experiment consists of two independent vegetated plots connected to the gutter through a concrete channel, which drives the runoff into the facility from the avenue next to it. Each plot has its own spillway, where samples were collected for laboratory analysis under 22 water quality parameters and thus compared to gutter runoff. Regarding construction techniques, it was decided to apply simplified solutions without unnecessary expenses, but that ensured feasibility, solidity and isolation to the plots from the ground on all faces. As for filling the model, it was chosen to use the same material for both facilities, laid out from bottom to surface: 60cm of broken rocks, 15cm of gravel, coconut geotextile fabric, 5cm of coarse sand and, finally, 45 to 75cm of planting substrate with side slopes and covered with mulch. Regarding vegetation cover, two sets of plants have been used in the bioretention cells as a research strategy to compare the efficiency among different models in stormwater management, considering other issues in addition to improving the environmental quality of water, such as maintenance, adaptation and development of species and visual interest. Thus, the experiment plots were filled with the same substrate but with different vegetable toppings, according to the following configuration: mixed garden (M) - ground covers with predominance of native shrubs and herbaceous vegetation, and lawn (L) - covered only with emerald grass carpet (Zoysia japonica), which has been extensively used for lawns all over the country. This experimental model has provided scientific answers that attest the effectiveness of techniques using vegetated surfaces to retain and treat stormwater. Its results have attested the performance of bioretention for diffuse pollution mitigation, with average reductions of accumulated pollutant loads of 89.94% in the lawn (L) and 95.49% in the mixed garden (M), which wasproven to be more efficient. This research developed by USP Faculty of Architecture and Urbanism in partnership with Polythecnic School, does not aim to threat conventional methods of urban drainage in local cities, but to join them in the efforts of reaching solutions and technical knowledge that are suitable for urban ecosystems and harmless to environment and landscape.
483

Les objets de nature : Quelles places dans la ville ? Conditions d’appropriation des dispositifs de gestion des eaux pluviales de la métropole lyonnaise / Natural objects : What places in the city? Conditions for appropriation of the rainwater management systems of the Lyon metropolis.

Ah Leung, Sébastien 23 June 2017 (has links)
En France, face aux problèmes liés au réseau d’assainissement hérité du XIXème siècle, une solution consiste à gérer les eaux pluviales par des techniques « alternatives » au réseau. Le « tout tuyau » fait place à un ensemble d’objets techniques hybrides, composés d’éléments naturels et de matériaux synthétisés. Ces « objets de nature » présentent une apparence mixte (naturelle/artificielle) et assurent des fonctions multiples qui peuvent rendre leur intégration difficile. Dans quelles mesures l’appropriation des objets de nature par les publics est-elle difficile? Comment s’établit la place des objets de nature dans la ville? Cette thèse vise plusieurs objectifs. Il s’agit de renseigner les relations entre publics et objets de nature, d’obtenir des éléments sur les pratiques et usages des publics et d’apporter une réflexion sur la manière d’étudier les comportements humains. Pour se faire, trois enquêtes basées sur de l’observation directe doublée par une prise d’images systématisée ont été menées au cours de quatre saisons et à travers 12 études de cas réparties au sein de la métropole lyonnaise. Ces enquêtes ont tout d’abord permis de préciser la construction de l’objet de nature en tant qu’instrument à travers le concept de genèse instrumentale de Rabardel. Ensuite, les pratiques, usages ainsi que les conditions d’utilisation des dispositifs ont pu être définis grâce aux comportements observés chez les publics. Enfin, les avantages et limites de l’observation directe et des conditions d’analyse des données ont été discutés dans le but d’apporter des pistes d’amélioration à cette méthodologie pour de futures études. / To better manage storm water and to respond to problems related to the sanitation networks conceived in the 19th Century, some alternative techniques, other than networks, are being put forward. The “all tubes” concept is giving way to various technical objects of a hybrid nature made up of natural components and synthesized material. The physical appearance of these “natural objects” is double (both natural and artificial) and they fulfil various purposes. Thus, their insertion in the landscape can be delicate. How are these natural objects seized by society? In this process are any difficulties encountered? How is the place for natural objects defined in a city? The purpose of this dissertation is triple: (1) gather information on the relationship between societies and natural objects, (2) collect data on the public's use and practices, (3) discuss a methodology to study human behavior. Three inquiries were carried out during the four seasons of the year and in twelve sites; they were based on direct observation and systematized photography. Based on the fieldwork and the concept of “genèse instrumentale” developed by Rabardel, a discussion was developed on the building of a natural object as a tool. Subsequently, based on the observation of the public, practices, uses and the conditions in which these natural objects are used were defined. The dissertation concludes by highlighting the advantages and the limits of direct observation, and by developing the biases such as the context in which the data was analyzed, in order to suggest some possible methodological enhancements which could help future studies.
484

Mesure et modélisation de la contamination du sol dans les ouvrages de gestion à la source du ruissellement urbain / Assessment of soil contamination in Sustainable Urban Drainage Systems (SUDS) through experimental and modelling approaches

Tedoldi, Damien 03 July 2017 (has links)
L'essor que connaît aujourd'hui la gestion intégrée des eaux pluviales s'accompagne d'un recours croissant à des techniques favorisant l'infiltration de l'eau “à la source”, disséminées sur des bassins versants urbains. Néanmoins, de telles pratiques suscitent des interrogations sur la capacité du sol à jouer le rôle de “filtre” vis-à-vis des polluants présents dans le ruissellement. Ces travaux de thèse s'intéressent à la contamination du sol par les métaux et les hydrocarbures aromatiques polycycliques (HAP) dans ces dispositifs, avec trois objectifs : (i) évaluer les niveaux et l'étendue spatiale de la contamination, (ii) mieux comprendre les mécanismes qui gouvernent le devenir de ces contaminants dans le sol des ouvrages, et (iii) proposer des recommandations sur la conception et la maintenance de ces installations, afin de leur assurer un fonctionnement épuratoire durable.La première partie du travail consiste en une série d'investigations expérimentales sur dix sites d'étude aux caractéristiques contrastées, en service depuis plus de dix ans. Cette phase donne lieu à des cartographies de la contamination superficielle en éléments traces métalliques, puis à des profils verticaux de métaux et HAP, accompagnés de différentes variables explicatives. La distribution spatiale des métaux en surface, qui est toujours structurée autour de la zone d'arrivée de l'eau, porte la signature du fonctionnement hydraulique réel des dispositifs, et révèle le caractère non-uniforme de l'infiltration lors des événements pluvieux courants, qui représentent la plus grande partie du flux polluant à l'échelle annuelle. Dans la zone la plus contaminée des ouvrages, métaux et HAP présentent un enrichissement significatif sur 10 à 40 centimètres de profondeur. La rétention des contaminants résulte de la combinaison de processus physico-chimiques (adsorption) et mécaniques (sédimentation et filtration) ; leur importance relative peut être quantifiée grâce au déficit de zirconium dans le sédiment urbain par rapport au bruit de fond géochimique local. La variabilité inter-sites des niveaux de contamination s'explique à la fois par les capacités de rétention du sol et par les flux de polluants issus du bassin versant d'apport. Bien que les teneurs de surface excèdent, sur certains sites, les seuils internationaux de remédiation du sol pour des espaces “multifonctionnels”, la zone concernée représente — latéralement et verticalement — une région assez limitée dans les ouvrages.La seconde partie de la thèse consiste en une approche de modélisation, dont la finalité est de décrire l'évolution à long terme de la contamination du sol, et d'évaluer l'incidence de différentes pratiques de conception ou de gestion. Une analyse de sensibilité est d'abord mise en œuvre afin d'identifier les “éléments-clés” dans la description du système, et d'orienter le choix du modèle. Les résultats montrent qu'une mauvaise estimation de la dispersivité ou de l'isotherme d'adsorption du sol est susceptible de biaiser significativement la prévision des profils de contamination. Dans la suite du travail, on propose une méthode visant à décrire l'infiltration non-uniforme et la filtration des polluants particulaires. Le modèle ainsi construit est validé via une comparaison entre mesures et simulations sur l'un des sites d'étude faisant l'objet d'une nouvelle caractérisation approfondie. Enfin, une analyse de scénarios illustre les bénéfices d'un amendement de l'horizon superficiel par un matériau adsorbant, ainsi que d'une répartition homogène des flux d'eau en surface, en matière de durée de vie des installations et de fréquence d'intervention. / Sustainable Urban Drainage Systems (SUDS) are increasingly used for stormwater management. However, the generalization of runoff infiltration in urban watersheds raises some concerns regarding the soil's ability to retain ubiquitous micropollutants. The present work addresses soil contamination by trace metals and polycyclic aromatic hydrocarbons (PAHs) in such infiltration devices, with the aims of: (i) appraising the levels and spatial extent of soil contamination, (ii) better understanding the mechanisms which govern the fate of contaminants in these systems, and (iii) identifying design and maintenance guidelines which may enhance long-term pollutant control through SUDS.The first part of the study consists in a series of experimental investigations in ten contrasting study sites, which have been in operation for more than ten years. The two-stage methodology successively leads to cartographies of metal contamination in the surface soil, and vertical profiles of metal and PAH concentrations, along with different explanatory variables. The spatial distribution of trace metals in the upper horizon displays a systematic structure with respect to the inflow area, and bears the time-integrated signature of the infiltration fluxes and flow pathways at the surface. In the most contaminated zone of the facilities, a significant enrichment of metals and PAHs is detectable until 10 to 40 cm depth. Contaminant retention results from the combination of different physicochemical and mechanical processes (resp. sorption and sedimentation/filtration), the contribution of which can be assessed via the zirconium deficit in urban sediment in comparison to the soil's geochemical background. The inter-site variability of contamination levels is attributable to (i) differences in the soil's retention capacities, and (ii) differences in pollutant loads from the watershed. Although surface contents may exceed intervention thresholds for “multi-functional” spaces in several study sites, the area which would require soil remediation is laterally and vertically limited.These experimental assessments are complemented by a modelling approach, to describe the long-term evolution of soil contamination, and to evaluate the effect of various SUDS designs and maintenance operations. A sensitivity analysis is first carried out so as to identify the “key elements” in the system description: the results show that a wrong estimation of the soil's dispersivity or sorption isotherm is likely to induce significant biases in the predicted contamination profiles. A method is then proposed to describe non-uniform water infiltration fluxes, and the filtration of particle-bound contaminants. The model is validated via a comparison between measured and predicted metal profiles in one of the study sites, where a comprehensive soil characterization is undertaken. Finally, a “scenario analysis” illustrates the benefits of (i) using soil enrichment products with enhanced sorption capacities, and (ii) facilitating water spreading at the surface, in terms of “lifespan” of the devices and maintenance requirements.
485

Dynamique des flux de micropolluants et mécanismes de dépollution des rejets pluviaux urbains stricts à travers une technique alternative : approche multi-échelles par des méthodes expérimentale et numérique / Dynamic of micropollutants fluxes and treatment mechanisms in an urban stormwater pond-filter constructed wetland

Walaszek, Milena 19 January 2018 (has links)
Afin de limiter les impacts négatifs des rejets pluviaux urbains stricts (RPUS) sur l’hydraulique et la qualité des milieux naturels, des techniques alternatives sont mises en place. A Strasbourg (France,67), une mare de sédimentation suivie d’un filtre planté de roseaux à écoulement vertical collecte, stocke et traite les eaux de ruissellement d’un bassin versant résidentiel (2,7ha) depuis 5 ans. L’objectif de cette thèse est de (i) déterminer l’efficacité hydraulique et de traitement de la filière, (ii) évaluer les dynamiques de stockage des métaux et des hydrocarbures aromatiques polycycliques en temps de pluie et en temps sec, (iii) anticiper l’impact des variations climatiques sur l’efficacité de la filière, (iv) évaluer le comportement de sorption du cuivre, plomb et zinc dans le filtre et (v) modéliser les flux en entrée et en sortie de la filière. Trois années de suivi hydraulique, hydrologique et physico-chimique sur le site et 13 campagnes de prélèvement en temps pluie ont permis de montrer que les efficacités de la filière sont constantes au cours de l’année. Les RPUS sont caractérisés par de fortes concentrations en zinc, et les concentrations en micropolluants sont dépendantes de l’importance de la pluie. De plus, des expériences réalisées sur le sable du filtre (analyses chimiques, extractions séquentielles, expériences batch) ont montré que la rétention des métaux dans le filtre dépend du pH et de la concentration en métaux. Un modèle basé sur l’équation de Richards a été développé et permet de reproduire avec succès les écoulements verticaux 1D dans le filtre. / Stormwaters are identified as a major source of pollution for waterbodies. Particularly, metals and Polycyclic Aromatic Hydrocarbons (PAHs) in stormwater are known as the most toxic compounds for the fauna and flora. To limit the impact of these micropollutants on hydrosystems quality, stormwater constructed wetlands (SCW) have been built worldwide. This study aims i) to assess the efficiency of a 5-years-old SCW that combined a sedimentation pond followed by a vertical flow sand filter in urban area (Strasbourg 67, France), ii) to determine micropollutants storage in water and soils during dry period, (iii) to investigate the seasonality impacts on SCW performances, (iv) to evaluate copper, lead and zinc sorption behavior on the filter sand and (v) to model micropollutants and rain water fluxes from the catchment to the filter output. 3 years of on-site monitoring and 13 rain event sampling campaigns have shown that SCW hydraulic and treatment performances are constant over the year. Rain water is characterized by high loads of zinc and its micropollutants loads depend on the rain event depth. Then, chemical analyses, sequential extractions and batch experiments performed on the SCW substrate highlight that metals mobility in the filter is affected by pH and metal concentration. A model based on the Richard’s equation has been developed and predicts with success the 1-D vertical flow in the filter.
486

O \'técnico-científico\' e o \'sociopolítico\' na gestão da água urbana: drenagem e manejo de águas pluviais no Município de São Paulo / Technical-scientific and sociopolitical aspects of urban water management: stormwater drainage in the city of São Paulo.

Borba, Maria Lucia Guilherme 23 April 2014 (has links)
Na cidade de São Paulo, as inundações, consideradas a consequência das chuvas intensas e da impermeabilização do solo urbano, têm causado impactos consideráveis. As contínuas e frequentes inundações e as intervenções para contê-las, de alto custo para o Poder Público, justificam a busca de uma abordagem complementar à puramente técnica-hidráulica, que dê atenção aos aspectos sociopolíticos inerentes à drenagem urbana e ao manejo de águas pluviais, o foco principal desta pesquisa. Seus objetivos são: uma análise crítica sobre a incorporação do sociopolítico na malha de disciplinas do curso de Engenharia Civil; uma análise crítica da visão dos profissionais envolvidos, direta ou indiretamente, com a gestão urbana sobre a incorporação de aspectos sociais no planejamento e na implantação de obras de drenagem urbana; e se estes aspectos são incorporados aos projetos de obras de drenagem e se atores sociais localizados na área de uma bacia hidrográfica valorizam esta incorporação. A pesquisa concluiu que, ainda que aspectos sociopolíticos estejam incorporados na malha de disciplinas dos cursos de Graduação em Engenharia Civil e ainda que os profissionais da gestão urbana valorizem os aspectos sociais tanto quanto os aspectos técnicos das obras de drenagem, o planejamento e a implantação de obras de drenagem em construção na área da bacia hidrográfica, foco geográfico desta pesquisa, não incorporam os aspectos relativos ao sociopolítico. A bibliografia consultada e os exemplos concretos apresentados mostram a importância da incorporação dos aspectos sociopolíticos nas intervenções. Os conceitos discutidos ajudaram a formular recomendações para a incorporação do sociopolítico na malha das disciplinas e nos projetos de obras hidráulicas. São recomendações que visam, além da preservação ambiental e do atendimento ao interesse público, maximizar os benefícios da solução técnica. / In the city of São Paulo, intensive rains and urban impervious cover are being held responsible for flooding events which have been causing increase in runoff volume and in peak discharge. The high costs of technical hydraulic interventions to contain the frequent flooding impacts justify the search for an alternative approach: the incorporation of the sociopolitical complexities of urban stormwater drainage, the main theme of this research. Its objectives are: understand if and how sociopolitical complexities are being incorporated to Civil Engineering education; how professionals directly or indirectly involved in urban stormwater management see the incorporation of sociopolitical complexities in planning and implementation of stormwater drainage construction works and, finally, if these complexities are integrated in the projects being planned and being implemented in an urban watershed area. The research concluded that Civil Engineering education incorporate courses which open space for the discussion of sociopolitical aspects; that professionals involved in urban management value the incorporation of sociopolitical aspects in planning and implementation of storm water construction projects, but that in the watershed area where projects are being implemented such aspects are not taken into account. The bibliography and the concrete examples examined show the importance of incorporating sociopolitical aspects in drainage construction projects. The concepts brought forward help identify recommendations for the incorporation of sociopolitical aspects in Civil Engineering education and in the planning and implementation of stormwater constructions projects. These are recommendations which aim at increasing environmental preservation, meeting the public interest and maximizing the benefits of the technical solution.
487

EVALUATION OF A SEQUENTIAL POND SYSTEM FOR DETENTION AND TREATMENT OF RUNOFF AT SKYPARK, SANTA'S VILLAGE

Caporuscio, Elizabeth 01 December 2018 (has links)
Understanding the extent to which human activities impact surface water resources has become increasingly important as both human population growth and related landscape changes impact water quality and quantity across varying geographical scales. Skypark, Santa’s Village is a 233.76-acre tourism-based outdoor recreation area located in Skyforest, California residing within the San Bernardino National Forest. The park is situated at Hooks Creek, the headwaters of the Mojave River Watershed, and is characterized by a diverse landscape that includes forest cover and human development, including impervious surfaces, a restored meadow, and recreational trails. In 2016, Hencks Meadow was considered degraded by human activity and restored by the Natural Resources Conservation Services (NRCS) using best management practices (BMPs) to manage stormwater runoff and mitigate pollutants entering recreational downstream surface water. Three BMP detention basins were constructed to store and improve water quality from stormwater runoff. The purpose of this study is to observe the extent to which the engineered BMP detention basins design were effective in mitigating stormwater pollution from entering Hooks Creek. Over a six to eight month period (January to August), ponds were tested in situ bi-weekly for temperature (ºC), dissolved oxygen (mg/L), pH, turbidity (NTU), conductivity (µS/cm), nitrate (mg/L), and ammonium (mg/L), with additional laboratory tests for total suspended solids (mg/L), total dissolved solids (mg/L), chemical oxygen demand (mg/L), total coliform (MPN/100mL), Escherichia coli (MPN/100mL), and trace metals (µg/L). The results of this study support that the BMP design is improving surface stormwater runoff from impervious surfaces before it enters Hooks Creek. Findings could also promote the design and implementation of stormwater BMP detention basins at other site locations where water degradation is evident. Furthermore, this research can be used to promote the necessary improvement of water quality and quantity on a widespread geographical scale.
488

Réponses écophysiologiques à une pollution d’origine anthropique chez un organisme sentinelle et conséquences sur le fonctionnement des bassins d’infiltration / Ecophysiological responses of anthropic pollution in a sentinelle organism and consequences on infiltration basin functioning

Pigneret, Mathilde 16 March 2018 (has links)
Les populations humaines sont exposées à de très nombreux polluants. Il apparaît donc essentiel d'évaluer la toxicité de ces molécules au sein des compartiments récepteurs. En milieu urbain, de nombreux polluants (principalement hydrocarbures et métaux lourds) s'accumulent sur les surfaces imperméables (routes, toitures, parkings, bâtiments…). Ils sont remis en suspension et drainés par les eaux de pluie jusque dans les bassins d'infiltration. Ces structures ont été construites afin de réinfiltrer les eaux de ruissellement dans les nappes phréatiques sous-jacentes et de les détoxifier. Ces molécules toxiques sont capturées et accumulées au niveau des sédiments fins constitutifs des bassins, où elles peuvent atteindre des concentrations très élevées. Malgré cette forte contrainte, quelques rares invertébrés vivent dans les sédiments pollués des bassins d'infiltration, ce qui sous-entend des adaptations métaboliques, physiologiques et/ou comportementales spécifiques. L'un des plus répandus est l'oligochète aquatique Limnodrilus hoffmeisteri. Ce ver tubificidé construit des galeries (activité de bioturbation) dans les sédiments où il favorise l'activité des microorganismes sur la minéralisation de la matière organique et le recyclage des nutriments. Cette espèce présente donc un rôle essentiel dans le fonctionnement des bassins d'infiltration, et donc sur la qualité de l'eau des nappes phréatiques. Elle est aujourd'hui considérée à la fois comme une espèce sentinelle de l'état de santé de son biotope et comme un ingénieur des écosystèmes. Le premier objectif de ce travail de thèse a été de mettre en évidence les réponses écophysiologiques permettant à L. hoffmeisteri de survivre dans ces biotopes particulièrement anthropisés. Pour cela, nous avons exposé/élevé cet organisme pendant 1, 3 ou 6 mois dans des sédiments pollués issus de 3 bassins d'infiltration et un sédiment issu d'un milieu non urbanisé (sédiment témoin très peu pollué), en laboratoire. Nous avons ensuite analysé sur ce ver la survie, la consommation d'oxygène, l'état des réserves énergétiques, les concentrations de métaux lourds bioaccumulés, le stress oxydant engendré par les polluants (niveau de peroxydation lipidique) et enfin les mécanismes de protection associés (activités des principales enzymes antioxydantes). Le deuxième objectif a été de déterminer l'impact des polluants urbains sur les métabolismes aérobie et anaérobie chez L. hoffmeisteri. Pour cela, nous avons mesuré différents paramètres témoignant de l'activité mitochondriale (activités de la chaîne respiratoire mitochondriale et de l'ATP synthétase) ainsi que les concentrations des principaux produits terminaux du métabolisme anaérobie chez des vers exposés aux mêmes sédiments (4) pollués ou témoin. Cette étude a démontré que les contaminants induisent une transition partielle du métabolisme aérobie vers les voies anaérobies suite à un dysfonctionnement mitochondrial, et a aussi révélé que certains produits terminaux du métabolisme anaérobie (succinate et propionate) constituent des marqueurs pertinents de la pollution urbaine. Enfin, le troisième objectif de cette thèse a été d'évaluer l'impact d'une pollution d'origine anthropique sur l'activité d'ingénierie de L. hoffmeisteri (i.e. sur son rôle dans le fonctionnement des bassins d'infiltration). Pour cela, nous avons mesuré pendant 1 mois le comportement de fouissage de ce ver bioturbateur par tomographie aux rayons X dans des microcosmes contenant des sédiments pollués ou non. De plus, des mesures régulières des flux de nutriments, d'oxygène dissous, de CO2 et de CH4 au cours de l'expérimentation ont permis d'évaluer l'influence du taux de contamination sur le recyclage des nutriments dans nos systèmes expérimentaux. Ces mesures ont été effectuées à la fois dans des systèmes colonisés par L. hoffmeisteri, mais aussi dans des systèmes sans faune, afin de quantifier précisément le rôle de ces organismes ingénieurs / Human populations are exposed to numerous pollutants. It is now necessary to evaluate the toxicity of urban contaminants in receptor ecosystems. In anthropized areas, many pollutants (mainly hydrocarbons and heavy metals) accumulate on the impervious surfaces (roads, parks, buildings, rooftops…). During a rainfall event, these compounds are re-suspended and drained up to stormwater infiltration basins. These structures were built to detoxify and to infiltrate runoff water to underlying groundwater. Toxic compounds are captured and accumulated in the fine sediment layer of the infiltration basins, where their concentrations may achieve important concentrations. Despite this harsh constraint, a few invertebrates inhabit stormwater basin sediments and have developed specific metabolic, physiological and/or behavioural adaptations. One of the most spread is the oligochaeta Limnodrilus hoffmeisteri. This tubificid worm burrows galleries (bioturbation activity) in sediments where it enhances the organic matter mineralization and the nutrients recycling. This species has an essential role in the infiltration basin functioning and on groundwater quality. L. hoffmeisteri is considered both as a sentinel species of ecosystem health and an engineer species. The first aim of this work was to highlight the ecophysiological responses that allow L. hoffmeisteri to survive in these harsh conditions. We exposed this organism during 1, 3 or 6 months to polluted sediments (from 3 infiltration basins), under laboratory conditions. Then, we measured the survival, the oxygen consumption, the energy body stores, the oxidative stress induced by urban pollutants (through the lipid peroxidation level), and the antioxidant defence mechanisms (the activity of the antioxidant enzymes) in L. hoffmeisteri. The same analyses were realized on worms incubated 1 to 6 months in a sediment from a non-urbanized environment (considered as a low-polluted/control sediment). The second objective of the present work was to determine the impact of urban pollutants on aerobic and anaerobic metabolisms in L. hoffmeisteri. We measured several mitochondrial parameters (the mitochondrial respiratory chain activity and the ATP production rate) and anaerobic end product concentrations in worms exposed to the 4 same sediments (polluted or not). This study demonstrated that urban pollutants induced a shift from aerobic to the anaerobic metabolism, linked to a mitochondrial dysfunctioning. Moreover, this study also showed that two anaerobic end products (succinate and propionate) constitute relevant biomarkers of urban pollution. Lastly, the third goal of this thesis was to evaluate the impact of an anthropic pollution on the engineering activity of L. hoffmeisteri (i.e. its role in the infiltration basin functioning). To this end, we measured during 1 month the burrowing activity of this tubificid worm using X-ray tomography, in microcosms containing slightly or highly polluted sediments. We measured nutrients fluxes, dissolved oxygen, CO2 and CH4 concentrations during the experiment to determine the influence of the pollution rate on nutrients recycling. These measurements were also realized in microcosms with or without worms, to quantify the functional role of engineer organisms
489

Masugnsslaggens potential som filtermaterial för metaller i vägdagvatten

Skogsfjord, Michael, Blom, Minna January 2008 (has links)
<p>Dagvatten från vägar innehåller ofta tungmetaller. De vanligaste metallerna i vägdagvatten är bly, koppar, kadmium, nickel och zink. Dessa föroreningar utgör en belastning i recipienter som tar emot dagvattnet. I denna rapport har bly, koppar och zink reducerats från vägdagvatten genom filtrering i kolonner med amorf, granulerad masugnsslagg och sand. Masugnsslagg, som är en biprodukt från framställningen av järn, är en alkalisk produkt med goda sorptionsegenskaper vilket gör den lämplig att använda som filtermaterial för vatten förorenade med metaller. Sanden användes i studien som referensmaterial. Masugnsslaggen som användes i denna studie är hyttsand från Merox, Oxelösund. Reningshalten för hyttsanden i denna studie uppgick till 79 % för bly, 82 % för koppar samt 92 % för zink. Hyttsandens reducerande förmåga har även undersökts i batchförsök.</p> / <p>Stormwater from roads often contain heavy metals. The most common metals in storm water from roads are lead, copper, cadmium, nickel, and zinc. These pollutants constitute a stress for organisms in recipients that receive the stormwater. In this report lead, copper and zinc have been reduced from road storm water through filtration in columns with granulated iron slag and sand. Iron slag is a by-product from the iron making process, with a high sorption capacity, which makes it suitable as a filter material for water polluted with metals. The sand in this study has been used as reference material. The reducing capacity in the stormwater for the iron slag used in this study, “hyttsand”, was 79 % for lead, 82 % for copper and 92 % for zinc. The reducing capacity of the iron slag was also investigated in batch studies.</p>
490

Insamling, rening och användning av vatten i den hållbara hemträdgården.

Wedrén, Malin January 2009 (has links)
<p>Utan vatten inget liv. Människor är beroende av rent vatten för sin överlevnad. I många länder orsakar idag bristen på rent vatten sjukdomar och för tidig död. Världens problem med sötvatten i form av brist och svåra föroreningar orsakade av människan kan te sig kolossala. Befolkningsökning och ändrade levnadssätt påverkar. Industrier och jordbruk har stor påverkan men också den enskilda människans vattenanvändning har betydelse.</p><p> </p><p>I Sverige tycks den allmänna inställningen vara att vi inte har ett problem med vårt användande av vatten. Men vid en närmare undersökning av vårt innanhav Östersjöns problem med exempelvis övergödning och syrebrist och utsläppen av näringsämnen ifrån våra enskilda avlopp kan man ställa sig frågande. Även svenskens nyttjande av grundvattenreserver kan te sig olämpligt utifrån ett ekologiskt hållbart perspektiv. Att sedan detta vatten renas till dricksvattenkvalitet för att sedermera användas till att vattna fuktälskande växter som är planterade i gassande sol i en sandig torr jord kan vara förbryllande. Medvetenhet utifrån det lilla perspektivet, till exempel den svenska hemträdgården, kan vara åskådligt. Samtidigt kan det kanske också bidra till en i framtiden miljövänligare politik där målet är att rent sötvattnen skall finnas tillgängligt för alla i ett långt perspektiv.</p><p> </p><p>I denna litteraturstudie, möjligheten till en rationell vattenanvändning i den privata hemträdgården ur ett ekologiskt hållbart perspektiv. Flertalet olika metoder att hushålla med vatten och att tillvarata, rena och använda sig av nederbörd och gråvatten belyses. Resultatet är indelat i två delar; hushållning och rening. I den första redogörs på vilka sätt en effektivisering av vattenanvändandet kan gå till. Lättast och effektivast görs detta genom att dra ner på förbrukningen. Detta går enkelt att göra med några få tekniker. Till exempel att bättra på jordstruktur med organisktmaterial, att placera växter på platser som liknar deras naturliga habitat, minska avdunstning och forma platsen så att nederbörd kan ledas dit den behövs. Att se över hur extrabevattning ska tillämpas på effektivast sätt samt vilken vattenkälla detta vatten kommer ifrån tillhör också detta hushållande stycke. I den andra delen redogörs för olika metoder som kan tillämpas i en trädgård för att rena grå- och dagvatten så att trädgårdens naturliga potential till att vara en del av jordens naturliga kretslopp främjas. Lättast görs detta genom en begränsning av föroreningar redan vid deras källa. Därefter kan infiltrationsytor, infiltrationsplanteringar, biodiken, gröna tak, dammar, konstruerade våtmarker, rotzoner, UV-ljus och aquakulturer vara mer eller mindre användbara metoder som kan tillämpas i hemträdgården.</p><p> </p><p>Vattenfrågan bör klarläggas redan vid planeringen av byggnader och trädgård. Varje tomt måste sättas in i sitt sammanhang då dessa unika med speciella förutsättningar och problem. Hemträdgården är en utmärkt plats för experiment och utvecklingsarbete av ett hållbart vattenanvändande.</p> / <p>Without water there would be no life on earth. People depend of clean water for their survival. Today in many countries the lack of clean water is causing disease and premature death. World problems with fresh water in the form of shortage and severe pollution caused by humans may seem colossal. Industries and agriculture have a major impact but also the individual’s water-use has consequences.</p><p> </p><p>In Sweden the public opinion seems to be that we do not have a problem with our use of water. But with a closer look on facts that is not the case. For example our inland sea, Östersjön, and our contribution to its problems with euthrophication, lack of oxygen with the spillage of nutrients from the sewers and agriculture. Also the Swedish use of ground water may seem inappropriate in an ecological sustainable perspective. What is even more puzzling is that this water gets cleaned to a drinking water quality and then gets used for watering plants in the garden or to wash the car. Consciousness from the small perspective (as the Swedish private garden) can contribute to a future environmentally friendly politic that will lead to a sustainable water-use in a long perspective.</p><p> </p><p> </p><p>With this paper I would like to demonstrate, in a literature study, the possibility of a rational water-use in the private home garden from an ecological sustainable perspective.  Different methods of economising the water-use, gathering and cleaning stormwater and greywater will be illustrated. The result part will be divided into two parts; economization of water and cleaning of water.</p><p> </p><p>The first part describes the ways in which an efficiency of water-use can be preceded. The easiest way this is done is to cut down the consumption of water. This can easily be done with a few techniques. For example to improve the soil structure with organic material, placing of plants in places that resemble their natural habitat, reduction of evaporation and shaping pf the site so that precipitation can be managed where it is needed. Also to in which way irrigation is applied in the most efficient way and from which source this water is taken is presented in this part. The second part describes different methods of cleaning grey- and stormwater so the home garden’s natural potential to be a part of the earth’s natural rhythm is promoted.</p><p>Most easily this is done by stopping the pollution at the source. After that infiltration areas, bioswales, green roofs, ponds, constructed wetlands, reed beds, UV light and aquacultures can be more or less potential methods to be applied in the home garden.</p><p> </p><p>Water issues should be clarified already at the design process with homes and gardens. Each plot and garden is unique with its particular conditions and problems. Therefore needs every case to be seen in its particular context in order to obtain the optimal solution for that particular place.The home garden is a suitable place for experimental development of a sustainable water-use.</p>

Page generated in 0.086 seconds