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Impacts of Climate Change on IDF Relationships for Design of Urban Stormwater SystemsSaha, Ujjwal January 2014 (has links) (PDF)
Increasing global mean temperature or global warming has the potential to affect the hydrologic cycle. In the 21st century, according to the UN Intergovernmental Panel on Climate Change (IPCC), alterations in the frequency and magnitude of high intensity rainfall events are very likely. Increasing trend of urbanization across the globe is also noticeable, simultaneously. These changes will have a great impact on water infrastructure as well as environment in urban areas. One of the impacts may be the increase in frequency and extent of flooding. India, in the recent years, has witnessed a number of urban floods that have resulted in huge economic losses, an instance being the flooding of Mumbai in July, 2005. To prevent catastrophic damages due to floods, it has become increasingly important to understand the likely changes in extreme rainfall in future, its effect on the urban drainage system, and the measures that can be taken to prevent or reduce the damage due to floods. Reliable estimation of future design rainfall intensity accounting for uncertainties due to climate change is an important research issue. In this context, rainfall intensity-duration-frequency (IDF) relationships are one of the most extensively used hydrologic tools in planning, design and operation of various drainage related infrastructures in urban areas. There is, thus, a need for a study that investigates the potential effects
of climate change on IDF relationships.
The main aim of the research reported in this thesis is to investigate the effect of climate change on Intensity-Duration-Frequency relationship in an urban area. The rainfall in Bangalore City is used as a case study to demonstrate the applications of the methodologies developed in the research
Ahead of studying the future changes, it is essential to investigate the signature of changes in the observed hydrological and climatological data series. Initially, the yearly mean temperature records are studied to find out the signature of global warming. It is observed that the temperature of Bangalore City shows an evidence of warming trend at a statistical confidence level of 99.9 %, and that warming effect is visible in terms of increase of minimum temperature at a rate higher than that of maximum temperature. Interdependence studies between temperature and extreme rainfall reveal that up to a certain range, increase in temperature intensifies short term rainfall intensities at a rate more than the average rainfall. From these two findings, it is clear that short duration rainfall intensities may intensify in the future due to global warming and urban heat island effect. The possible urbanization signatures in the extreme rainfall in terms of intensification in the evening and weekends are also inferred, although inconclusively. The IDF relationships are developed with historical data and changes in the long term daily rainfall extreme characteristics are studied. Multidecedal oscillations in the daily rainfall extreme series are also examined. Further, non-parametric trend analyses of various indices of extreme rainfall are carried out to confirm that there is a trend of increase in extreme rainfall amount and frequency, and therefore it is essential to the study the effects of climate change on the IDF relationships of the Bangalore City.
Estimation of future changes in rainfall at hydrological scale generally relies on simulations of future climate provided by Global Climate Models (GCMs). Due to spatial and temporal resolution mismatch, GCM results need to be downscaled to get the information at station scale and at time resolutions necessary in the context of urban flooding. The downscaling of extreme rainfall characteristics in an urban station scale pose the following challenges: (1) downscaling methodology should be efficient enough to simulate rainfall at the tail of rainfall distribution (e.g., annual maximum rainfall), (2) downscaling at hourly or up to a few minutes temporal resolution is required, and (3) various uncertainties such as GCM uncertainties, future scenario uncertainties and uncertainties due to various statistical methodologies need to be addressed. For overcoming the first challenge, a stochastic rainfall generator is developed for spatial downscaling of GCM precipitation flux information to station scale to get the daily annual maximum rainfall series (AMRS). Although Regional Climate Models (RCMs) are meant to simulate precipitation at regional scales, they fail to simulate extreme events accurately. Transfer function based methods and weather typing techniques are also generally inefficient in simulating the extreme events. Due to its stochastic nature, rainfall generator is better suited for extreme event generation. An algorithm for stochastic simulation of rainfall, which simulates both the mean and extreme rainfall satisfactorily, is developed in the thesis and used for future projection of rainfall by perturbing the parameters of the rainfall generator for the future time periods. In this study, instead of using the customary two states (rain/dry) Markov chain, a three state hybrid Markov chain is developed. The three states used in the Markov chain are: dry day, moderate rain day and heavy rain day. The model first decides whether a day is dry or rainy, like the traditional weather generator (WGEN) using two transition probabilities, probabilities of a rain day following a dry day (P01), and a rain day following a rain day (P11). Then, the state of a rain day is further classified as a moderate rain day or a heavy rain day. For this purpose, rainfall above 90th percentile value of the non-zero precipitation distribution is termed as a heavy rain day. The state of a day is assigned based on transition probabilities (probabilities of a rain day following a dry day (P01), and a rain day following a rain day (P11)) and a uniform random number. The rainfall amount is generated by Monte Carlo method for the moderate and heavy rain days separately. Two different gamma distributions are fitted for the moderate and heavy rain days. Segregating the rain days into two different classes improves the process of generation of extreme rainfall. For overcoming the second challenge, i.e. requirement of temporal scales, the daily scale IDF ordinates are disaggregated into hourly and sub-hourly durations. Disaggregating continuous rainfall time series at sub-hourly scale requires continuous rainfall data at a fine scale (15 minute), which is not available for most of the Indian rain gauge stations. Hence, scale invariance properties of extreme rainfall time series over various rainfall durations are investigated through scaling behavior of the non-central moments (NCMs) of generalized extreme value (GEV) distribution. The scale invariance properties of extreme rainfall time series are then used to disaggregate the distributional properties of daily rainfall to hourly and sub-hourly scale. Assuming the scaling relationships as stationary, future sub-hourly and hourly IDF relationships are developed.
Uncertainties associated with the climate change impacts arise due to existence of several GCMs developed by different institutes across the globe, climate simulations available for different
representative concentration pathway (RCP) scenarios, and the diverse statistical techniques available for downscaling. Downscaled output from a single GCM with a single emission scenario represents only a single trajectory of all possible future climate realizations and cannot be representative of the full extent of climate change. Therefore, a comprehensive assessment of future projections should use the collective information from an ensemble of GCM simulations. In this study, 26 different GCMs and 4 RCP scenarios are taken into account to come up with a range of IDF curves at different future time periods. Reliability ensemble averaging (REA) method is used for obtaining weighted average from the ensemble of projections. Scenario uncertainty is not addressed in this study. Two different downscaling techniques (viz., delta change and stochastic rainfall generator) are used to assess the uncertainty due to downscaling techniques. From the results, it can be concluded that the delta change method under-estimated the extreme rainfall compared to the rainfall generator approach. This study also confirms that the delta change method is not suitable for impact studies related to changes in extreme events, similar to some earlier studies. Thus, mean IDF relationships for three different future extreme events, similar to some earlier studies. Thus, mean IDF relationships for three different future
periods and four RCP scenarios are simulated using rainfall generator, scaling GEV method, and REA method. The results suggest that the shorter duration rainfall will invigorate more due to climate change. The change is likely to be in the range of 20% to 80%, in the rainfall intensities across all durations.
Finally, future projected rainfall intensities are used to investigate the possible impact of climate change in the existing drainage system of the Challaghatta valley in the Bangalore City by running the Storm Water Management Model (SWMM) for historical period, and the best and the worst case scenario for three future time period of 2021–2050, 2051–2080 and 2071–2100. The results indicate that the existing drainage is inadequate for current condition as well as for future scenarios. The number of nodes flooded will increase as the time period increases, and a huge change in runoff volume is projected. The modifications of the drainage system are suggested by providing storage pond for storing the excess high speed runoff in order to restrict the width of the drain The main research contribution of this thesis thus comes from an analysis of trends of extreme rainfall in an urban area followed by projecting changes in the IDF relationships under climate change scenarios and quantifying uncertainties in the projections.
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Modélisation distribuée à base physique du transfert hydrologique des polluants routiers de l’échelle locale à l’échelle du quartier / Distributed and physically-based modelling of hydrological transfer of road pollutants from local to city district scalesHong, Yi 03 January 2017 (has links)
Le développement des réseaux séparatifs entraîne le transfert fréquent de polluants urbains vers les milieux récepteurs (plans d’eau, rivières, etc.). La compréhension des processus de production et de lessivage des polluants dans le milieu urbain est pourtant incomplète à l’heure actuelle. Afin de répondre aux questions liées à la gestion des eaux urbaines, l’amélioration des connaissances des processus physiques est nécessaire, tant au niveau des surfaces urbaines que les réseaux d'assainissement. Pour cela, la modélisation du transfert hydrologique des polluants en milieu urbain peut être un outil précieux.Cette thèse a pour objectif de développer et d'analyser des modèles distribués à base physique pour simuler les flux de polluants routiers (Matières En Suspension (MES), Hydrocarbures, Métaux) dans un environnement urbain. Elle s'inscrit dans le cadre du projet ANR "Trafipollu" et bénéficie des résultats expérimentaux mis en œuvre dans ce projet pour la calibration et validation des modèles utilisés. Le travail de thèse s’articule autour de deux échelles de modélisation : l’échelle locale et l’échelle du quartier.A l'échelle locale, le code FullSWOF (volumes finis, schéma numérique d'ordre 2) couplé au modèle d’érosion d'Hairsine and Rose (1992a; 1992b) et des données géographiques très détaillées (résolution spatiale centimétrique) ont été utilisés et adaptés afin d'améliorer nos connaissances des processus physiques du lessivage des polluants sur les surfaces urbaines. La comparaison aux mesures en continu permet d’évaluer la performance d’une modélisation physique pour représenter les variations spatiales et temporelles des processus de transferts des polluants sur les surfaces urbaines. Les analyses des résultats obtenus permettent de constater la prédominance des effets d'arrachement liés à la pluie sur les processus d'entrainement par l'advection sur la majeure partie du bassin versant routier. L’utilisation d’un modèle d’érosion pour modéliser le transport particulaire en zone urbaine est une innovation importante de cette thèse.A l’échelle du quartier, la deuxième étape du travail consiste à coupler séquentiellement le modèle TREX (Velleux, England, et al., 2008) avec le modèle CANOE (Alison, 2005), nommé "TRENOE" plateforme. En changeant différentes options de mise en œuvre et de configurations du modèle, l’adaptation de la précision numérique et l’utilisation de données détaillées d’occupation du sol semblent être les facteurs clés pour une telle modélisation. Par ailleurs, ce couplage a montré des problèmes de fond tels que la modélisation du schéma numérique des flux en surface (seulement dans 4 directions), ainsi que l'utilisation de l'équation USLE pour simuler l'érosion en milieu urbain, ne comprenant pas d’impact des gouttes de pluie pour la modélisation.Pour remédier à ces défauts, la plateforme opensource LISEM-SWMM est développée en couplant le modèle LISEM (De Roo, Wesseling, et al., 1996), modèle d’érosion développé initialement pour le milieu naturel, et le modèle SWMM (Rossman, 2010). Pour la première fois, la modélisation hydrologique s’appuie aussi sur l’utilisation de sorties de modèles atmosphériques pour les dépôts des particules fines (PM10), hydrocarbures et métaux. Les résultats montrent que l’emploi de modèles totalement distribués peut arriver à reproduire de manière très fine les dynamiques des particules, des hydrocarbures et des métaux. Même si à ce stade la plateforme développée nécessite des améliorations pour adapter aux utilisations dans le champ opérationnel, ceci constitue une avancée pour le domaine de modélisation du transfert hydrologique des polluants routiers en milieu urbain / Nowadays, the increasing use of separate stormwater systems causes a frequent transport of urban pollutants into receiving water bodies (lakes, rivers). However, current studies still lack of the knowledge of urban build-up and wash-off processes. In order to address urban management issues, better understanding of physical mechanism is required not only for the urban surfaces, but also for the sewer systems. In this context, the modelling of hydrological transfer of urban pollutants can be a valuable tool.This thesis aims to develop and assess the physically-based and distributed models to simulate the transport of traffic-related pollutants (suspended solids, hydrocarbons, heavy metals) in urban stormwater runoffs. This work is part of the ANR "Trafipollu" project, and benefit from the experimental results for model calibration and validation. The modelling is performed at two scales of the urban environment: at the local scale and at the city district scale.At the local scale of urban environment, the code FullSWOF (second-order finite volume scheme) coupled with Hairsine and Rose model (1992a; 1992b) and detailed monitoring surveys is used to evaluate urban wash-off process. Simulations over different rainfall events represent promising results in reproducing the various dynamics of water flows and particle transfer on the urban surfaces. Spatial analysis of wash-off process reveals that the rainfall-driven impacts are two orders of magnitude higher than flow-drive effects. These findings contribute to a significant improvement in the field of urban wash-off modelling. The application of soil erosion model to the urban context is also an important innovation.At the city district scale, the second step consists of coupling the TREX model (Velleux, England, et al., 2008) and the CANOE model, named "TRENOE" platform. By altering different options of model configurations, the adequate numerical precision and the detailed information of landuse data are identified as the crucial elements for achieving acceptable simulations. Contrarily, the high-resolution topographic data and the common variations of the water flow parameters are not equally significant at the scale of a small urban catchment. Moreover, this coupling showed fundamental problems of the model structure such as the numerical scheme of the overland flow (only 4 directions), and the empirical USLE equations need to be completed by raindrop detachment process.To address these shortcomings, the LISEM - SWMM platform is developed by coupling the open-source LISEM model (De Roo, Wesseling, et al., 1996), which is initially developed for soil erosion simulations, and the SWMM model (Rossman, 2010). For the first time, the hydrological model is also supported by the simulations of atmospheric dry deposits of fine particles (PM10), hydrocarbons and heavy metals. The performance of water flow and TSS simulations are satisfying with the calibrated parameters. Considering the hydrocarbons and heavy metals contents of different particle size classes, simulated event mean concentration of each pollutant is comparable to local in-situ measurements. Although the platform at current stage still needs improvements in order to adapt to the operational applications, the present modelling approach contributes to an innovative technology in the field of modelling of hydrological transfer of the traffic-related pollutants in urban environment
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Urbanistická opatření pro efektivní hospodaření s povrchovou vodou v zastavěných územích / Urban measures of effective surface water management in urban areasVacková, Michaela January 2017 (has links)
One of the main challenges in promoting rainwater management into practise is the fact that it was not recognized as an interdisciplinary issue. We should seek ways how to open the problem to other professions, specially for architects and urban planners, who are the key element of its farther development. This work analyzes the reasons of this unsatisfactory state of rainwater management in the Czech Republic and it defines the possible ways how to remedy this state and outlines scenarios of its further development. The default document of the work is czech technical standard "TNV 75 9010 Hospodaření se srážkovými vodami". The new methodological guide, which is part of this work, is based on it. The work extends the range of measures which are mentioned in the standard. It brings new ways for assessing the benefits of the various measures to streamline the application of rainwater management measures in urban space.
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Zdravotně technické a plynovodní instalace v polyfunkčním domě / Sanitation installations and gas installations in the multifunctional buildingKousal, Tomáš January 2018 (has links)
The master thesis deals with sanitation installations and gas installations in the new multifunctional building situated in Kroměříž. The theoretical part is focused on analysis of the topic. It describes in detail possibilities of rainwater management and it compares its design by both valid standarts and valid regulations. Technical part solves sanitation installations and gas installations of assigned building with the chosen option.
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Impact of Climate Change on the Storm Water System in Al Hillah City-IraqAl Janabi, Firas 13 November 2014 (has links)
The impact of climate change is increasingly important to the design of urban water infrastructure like stormwater systems, sewage systems and drinking water systems. Growing evidence indicates that the water sector will not only be affected by climate change, but it will reflect and deliver many of its impacts through floods, droughts, or extreme rainfall events. Water resources will change in both quantity and quality, and the infrastructure of stormwater and wastewater facilities may face greater risk of damage caused by storms, floods and droughts. The effect of the climate change will put more difficulties on operations to disrupted services and increased cost of the water and wastewater services. Governments, urban planners, and water managers should therefore re-examine development processes for municipal water and wastewater services and are adapt strategies to incorporate climate change into infrastructure design, capital investment projects, service provision planning, and operation and maintenance.
According to the Intergovernmental Panel on Climate Change, the global mean temperature has increased by 0,7 °C during the last 100 years and, as a consequence, the hydrological cycle has intensified with, for example, more acute rainfall events. As urban drainage systems have been developed over a long period of time and design criteria are based upon climatic characteristics, these changes will affect the systems and the city accordingly.
The overall objective of this thesis is to increase the knowledge about the climate change impacts on the stormwater system in Al Hillah city/Iraq. In more detail, the objective is to investigate how climate change could affect urban drainage systems specifically stormwater infrastructure, and also to suggest an adaptation plan for these changes using adaptation plans examples from international case studies.
Three stochastic weather generators have been investigated in order to understand the climate and climate change in Al Hillah. The stochastic weather generators have been used in different kind of researches and studies; for example in hydrology, floods management, urban water design and analysis, and environmental protection. To make such studies efficient, it is important to have long data records (typically daily data) so the weather generator can generate synthetic daily weather data based on a sound statistical background. Some weather generators can produce the climate change scenarios for different kind of global climate models. They can be used also to produce synthetic data for a site that does not have enough data by using interpolation methods. To ensure that the weather generator is fitting the climate of the region properly, it should be tested against observed data, whether the synthetic data are sufficiently similar. At the same time, the accuracy of the weather generator is different from region to region and depends on the respective climate properties. Testing three weather generators GEM6, ClimGen and LARS-WG at eight climate stations in the region of Babylon governorate/Iraq, where Al Hillah is located, is one of the purposes of the first part of this study.
LARS-WG uses a semi-parametric distribution (developed distribution), whereas GEM6 and ClimGen use a parametric distribution (less complicated distribution). Different statistical tests have been selected to compare observed and synthetic weather data for the same kind, for instance, the precipitation and temperature distribution (wet and dry season). The result shows that LARS-WG represents the observed data for Babylon region in a better way than ClimGen, whereas GEM6 seems to misfit the observed data. The synthetic data will be used for a first simulation of urban run-off during the wet season and the consequences of climate change for the design and re-design of the urban drainage system in Al Hillah.
The stochastic weather generator LARS is then used to generate ensembles of future weather data using five Global Climate Models (GCMs) that best captured the full range of uncertainty. These Global Climate Models are used to construct future climate scenarios of temperature and precipitation over the region of Babylon Governorate in Iraq. The results show an increase in monthly temperatures and a decrease in the total amount of rain, yet the extreme rain events will be more intense in a shorter time.
Changes in the amount, timing, and intensity of rain events can affect the amount of stormwater runoff that needs to be controlled. The climate change calculated projections may make existing stormwater-related flooding worse. Different districts in Al Hillah city may face more frequent stormwater floods than before due to the climate change projections.
All the results that have been taken from the Global Climate Models are in a daily resolution format and in order to run the Storm Water Management Model it is important to have all data in a minimum of one hour resolution. In order to fulfill this condition a disaggregation model has been used. Some hourly precipitation data were required to calibrate the temporal disaggregation model; however none of the climate stations and rain gauges in the area of interest have hourly resolution data, so the hourly data from Baghdad airport station have been used for that calibration.
The changes in the flood return periods have been seen in the projected climate change results, and a return period will only remain valid over time if environmental conditions do not change. This means that return periods used for planning purposes may need to be updated more often than previously, because values calculated based on the past 30 years of data may become unrepresentative within a relatively short time span. While return periods provide useful guidance for planning the effects of flooding and related impacts, they need to be used with care, and allowances have to be made for extremes that may occur more often than may be expected.
In the study area with separated stormwater systems, the Storm Water Management Model simulation shows that the number of surface floods as well as of the floods increases in the future time periods 2050s and 2080s. Future precipitation will also increase both the flooding frequency and the duration of floods; therefore the need to handle future situations in urban drainage systems and to have a well-planned strategy to cope with future conditions is evident.
The overall impacts on urban drainage systems due to the increase of intensive precipitation events need to be adapted. For that reason, recommendations for climate change adaptation in the city of Al Hillah have been suggested. This has been accomplished by merging information from the review of five study cases, selected based on the amount and quality of information available. The cities reviewed are Seattle (USA), Odense (Denmark), Tehran (Iran), and Khulna (Bangladesh).:Preface
Acknowledgment
Abstract
Kurzfassung
Contents
List of Figures
List of Tables
List of Listing
List of Abbreviation
Introduction
1.1. Background of The Research
1.2. The Climate Change Challenge
1.3. Urban Water Systems and Climate Change
1.4. Climate Change and Urban Drainage Adaptation Plan
1.5. Objectives of the Research
1.6. Research Problems and Hypothesis
1.7. Dissertation Structure
1.8. Delimitations
Climate History and Climate Change Projections in Al Hillah City
Chapter One: State of the Art on Climate Change
2.1.1. The Earth’s Climate System
2.1.2. Climate Change
2.1.3. Emission Scenarios
2.1.4. Global Climate Change
2.1.5. Climate Models
2.1.6. Downscaling
Chapter Two: Topography and Climate of the Study Area
2.2.1. Location
2.2.2. Topography
2.2.3. Climate
Chapter Three: Climate Change - Methodology and Data
2.3.1. Methodology
2.3.1.1. Stochastic Weather Generators
2.3.1.2. Description of Generators Used in the Comparison
2.3.1.3. Statistical Analysis Comparison Test
2.3.2. Data
2.3.2.1. Required data for modelling
2.3.2.2. Historical daily data required for the weather generators
2.3.2.3. Minimum requirements
2.3.2.4. Data Availability
Chapter Four: Results Analysis and Evaluation of Climate Change
2.4.1. Weather Generators Comparison Test results
2.4.1.1.The p-value test
Temperature Comparison results
Precipitation Comparison Results
2.4.2. LARS Weather Generator Future Scenario
2.4.2.1.1. Climate Change Scenarios for the region of Babylon governorate
Storm Water System and Urban Flooding in Al Hillah City
Chapter one: Urban Water Modelling
3.1.1. General Overview and Background
3.1.1.1. Storm water systems
3.1.2. Urban Runoff Models
3.1.3. An Overview of Runoff Estimation Methods
3.1.3.1. Computer Modelling in Urban Drainage
3.1.3.2.Statistical Rational Method (SRM)
3.1.4. Models Based on Statistical Rational Method
3.1.5. Urban Rainfall-Runoff Methods
3.1.6. Accuracy Level in Urban Catchment Models
Chapter Two: Urban Water System in Al Hillah City and Data Requirement for Modelling
3.2.1. History
3.2.2. Current Situation
3.2.2.1. Urban water system Iraq
3.2.2.2. Urban Water description in Babylon governorate
3.2.2.3. Drinking water network
3.2.2.4. Sewerage infrastructure
3.2.3. Required data for modelling
Chapter Three: Methodology to Disaggregate Daily Rain Data and Model Storm Water Runoff
3.3.1. Temporal Disaggregation (hourly from daily)
3.3.1.1. Background of Disaggregation
3.3.1.2. Disaggregation techniques
3.3.1.3. DiMoN Disaggregation Tool
3.3.1.4. Input Data
3.3.1.5. Methods Formerly Used
3.3.2. EPA Storm Water Management Model (SWMM)
3.3.2.1. Verification and Calibration
3.3.2.2. Stormwater Management Model PCSWMM
3.3.2.3. Complete support for all USEPA SWMM5 engine capabilities
Chapter Four: Urban Flooding Results
3.4.1. Disaggregation of the daily rain data to hourly data
3.4.1.1.The 1 hour events properties
3.4.1.2. Estimating the rain events in each climate change scenario
3.4.1.3. Past, Current and future return periods
3.4.2. Storm Water Management Model PCSWMM Calibration
3.4.3.Return periods and Urban Floods
3.4.3.1.Network simulation
3.4.3.2.Properties with previous flooding problems
3.4.3.3.Storm water system simulation under 1 hour-2, 5 and 10 years return period
3.4.3.4.Storm water system simulation under 1 hour-25 years return period
3.4.3.5.Storm water system simulation under 1 hour-50 years return period
3.4.3.6. Storm water system simulation under 1 hour – 100, 200, 500 and 1000 years return period
3.4.3.7.Total Flooding
Adaptation Plan for Al Hillah City
Chapter One: International Case Studies
4.1.1. Historical precipitation analysis
4.1.2. Current and projected future climate change, impacts and adaptation plan for each selected city
4.1.2.1. Seattle
4.1.2.2. Odense
4.1.2.3. Tehran
4.1.2.4. Khulna
4.1.2.5. Melbourne
4.1.3. Drainage System of the Studied Cities
4.1.3.1. Drainage System in Seattle
4.1.3.2. Drainage System in Odense
4.1.3.3. Drainage System in Tehran
4.1.3.4. Drainage System in Khulna
4.1.3.5. Drainage System in Melbourne
Chapter Two: Adaptation Plan for Al Hillah City
4.2.1. Conclusions from Adaptation Options Analysed
4.2.2. Suggestions for Al Hillah City
4.2.3. Adaptation Actions
Overall Conclusion
Bibliography / Die Auswirkungen des Klimawandels auf die Gestaltung der städtischen Wasserinfrastruktur wie Regenwasser, Kanalisation und Trinkwassersysteme werden immer wichtiger. Eine wachsende Anzahl von Belegen zeigt, dass der Wassersektor nicht nur durch den Klimawandel beeinflusst werden wird, aber er wird zu reflektieren und liefern viele seiner Auswirkungen durch Überschwemmungen, Dürren oder extreme Niederschlagsereignisse. Die Wasserressourcen werden sich in Quantität und Qualität verändern, und die Infrastruktur von Regen-und Abwasseranlagen kann einer größeren Gefahr von Schäden durch Stürme, Überschwemmungen und Dürren ausgesetzt sein. Die Auswirkungen des Klimawandels werden zu mehr Schwierigkeiten im Betrieb gestörter Dienstleistungen und zu erhöhten Kosten für Wasser-und Abwasserdienstleistungen führen. Regierungen, Stadtplaner, und Wasser-Manager sollten daher die Entwicklungsprozesse für kommunale Wasser-und Abwasserdienstleistungen erneut überprüfen und Strategien anpassen, um den Klimawandel in Infrastruktur-Design, Investitionsprojekte, Planung von Leistungserbringung, sowie Betrieb und Wartung einzuarbeiten.
Nach Angaben des Intergovernmental Panel on Climate Change hat die globale Mitteltemperatur in den letzten 100 Jahren um 0,7 °C zugenommen, und in der Folge hat sich der hydrologische Zyklus intensiviert mit, zum Beispiel, stärkeren Niederschlagsereignisse. Da die städtischen Entwässerungssysteme über einen langen Zeitraum entwickelt wurden und Design-Kriterien auf klimatischen Eigenschaften beruhen, werden diese Veränderungen die Systeme und die Stadt entsprechend beeinflussen.
Das übergeordnete Ziel dieser Arbeit ist es, das Wissen über die Auswirkungen des Klimawandels auf das Regenwasser-System in der Stadt Hilla / Irak zu bereichern. Im Detail ist das Ziel, zu untersuchen, wie der Klimawandel die Siedlungsentwässerung und insbesondere die Regenwasser-Infrastruktur betreffen könnte. Desweiteren soll ein Anpassungsplan für diese Änderungen auf der Grundlage von beispielhaften Anpassungsplänen aus internationalen Fallstudienvorgeschlagen werden.
Drei stochastische Wettergeneratoren wurden untersucht, um das Klima und den Klimawandel in Hilla zu verstehen. Stochastische Wettergeneratoren wurden in verschiedenen Untersuchungen und Studien zum Beispiel in der Hydrologie sowie im Hochwasser-Management, Siedlungswasser-Design- und Analyse, und Umweltschutz eingesetzt. Damit solche Studien effizient sind, ist es wichtig, lange Datensätze (in der Regel Tageswerte) haben, so dass der Wettergenerator synthetische tägliche Wetterdaten erzeugen kann, dieauf einem soliden statistischen Hintergrund basieren. Einige Wettergeneratoren können Klimaszenarien für verschiedene Arten von globalen Klimamodellen erzeugen. Sie können unter Verwendung von Interpolationsverfahren auch synthetische Daten für einen Standort generieren, für den nicht genügend Daten vorliegen.
Um sicherzustellen, dass der Wettergenerator dem Klima der Region optimal entspricht, sollte gegen die beobachteten Daten geprüft werden, ob die synthetischen Daten ausreichend ähnlich sind. Gleichzeitig unterscheidet sich die Genauigkeit des Wettergenerator von Region zu Region und abhängig von den jeweiligen Klimaeigenschaften. Der Zweck des ersten Teils dieser Studie ist es daher, drei Wettergeneratoren, namentlich GEM6, ClimGen und LARS-WG, an acht Klimastationen in der Region des Gouvernements Babylon / Irak zu testen. LARS-WG verwendet eine semi-parametrische Verteilung (entwickelte Verteilung), wohingegen GEM6 und ClimGen eine parametrische Verteilung (weniger komplizierte Verteilung) verwenden. Verschiedene statistische Tests wurden ausgewählt, um die beobachteten und synthetischen Wetterdaten für identische Parameter zu vergleichen, zum Beispiel die Niederschlags- und Temperaturverteilung (Nass-und Trockenzeit). Das Ergebnis zeigt, dass LARS-WG die beobachteten Daten für die Region Babylon akkurater abzeichnet, als ClimGen, wobei GEM6 die beobachteten Daten zu verfehlen scheint. Die synthetischen Daten werden für eine erste Simulation des städtischen Run-offs in der Regenzeit sowie der Folgen des Klimawandels für das Design und Re-Design des städtischen Entwässerungssystems in Hilla verwendet.
Der stochastische Wettergenerator LARS wird dann verwendet, um Gruppen zukünftiger Wetterdaten unter Verwendung von fünf globalen Klimamodellen (GCM), die das gesamte Spektrum der Unsicherheit am besten abdecken, zu generieren. Diese globalen Klimamodelle werden verwendet, um zukünftige Klimaszenarien der Temperatur und des Niederschlags für die Region Babylon zu konstruieren. Die Ergebnisse zeigen, eine Steigerung der monatlichen Temperaturen und eine Abnahme der Gesamtmenge der Regen, wobei es jedoch extremere Regenereignissen mit höherer Intensivität in kürzerer Zeit geben wird.
Veränderungen der Höhe, des Zeitpunkt und der Intensität der Regenereignisse können die Menge des Abflusses von Regenwasser, die kontrolliert werden muss, beeinflussen. Die Klimawandel-Prognosen können bestehende regenwasserbedingte Überschwemmungen verschlimmern. Verschiedene Bezirke in Hilla können stärker von Regenfluten betroffen werden als bisher aufgrund der Prognosen.
Alle Ergebnisse, die von den globalen Klimamodellen übernommen wurden, sind in täglicher Auflösung und um das Regenwasser-Management-Modell anzuwenden, ist es wichtig, dass alle Daten in einer Mindestauflösung von einer Stunde vorliegen. Zur Erfüllung dieser Bedingung wurde ein eine Aufschlüsselungs-Modell verwendet. Einige Stunden-Niederschlagsdaten waren erforderlich, um das zeitliche Aufschlüsselungs-Modell zu kalibrieren. Da weder die Klimastationen noch die Regen-Messgeräte im Interessenbereich über stundenauflösende Daten verfügt, wurden die Stundendaten von Flughäfen in Bagdad verwendet.
Die Veränderungen in den Hochwasserrückkehrperioden sind in den projizierten Ergebnissen des Klimawandels ersichtlich, und eine Rückkehrperiode wird nur dann über Zeit gültig bleiben, wenn sich die Umweltbedingungen nicht ändern. Dies bedeutet, dass Wiederkehrperioden, die für Planungszwecke verwendet werden, öfter als bisher aktualisiert werden müssen, da die auf Grundlage von Daten der letzten 30 Jahre berechneten Werte innerhalb einer relativ kurzen Zeitspanneunrepräsentativ werden können. Während Wiederkehrperioden bieten nützliche Hinweise für die Planung die Effekte von Überschwemmungen und die damit verbundenen Auswirkungen, müssen aber mit Vorsicht verwendet werden, und Extreme, die öfter eintreten könnten als erwartet, sollten berücksichtigt werden.
Im Studienbereich mit getrennten Regenwassersystemen zeigt die Simulation des Regenwasser-Management-Modells, dass sich die Anzahl der Oberflächenhochwasser sowie der Überschwemmungen im Zeitraum 2050e-2080 erhöhen wird. Zukünftige Niederschläge werdensowohl die Hochwasser-Frequenz als auch die Dauer von Überschwemmungen erhöhen. Daher ist die Notwendigkeit offensichtlich, zukünftige Situationen in städtischen Entwässerungssystemen zu berücksichtigen und eine gut geplante Strategie zu haben, um zukünftige Bedingungen zu bewältigen.
Die gesamten Auswirkungen auf die Siedlungsentwässerungssyteme aufgrund der Zunahme von intensiven Niederschlagsereignissen müssen angepasst werden. Aus diesem Grund wurden Empfehlungen für die Anpassung an den Klimawandel in der Stadt Hilla vorgeschlagen. Diese wurden durch die Zusammenführung von Informationen aus der Prüfung von fünf Fallstudien, ausgewählt aufgrund der Menge und Qualität der verfügbaren Informationen, erarbeitet,. Die bewerteten Städte sind Seattle (USA), Odense (Dänemark), Teheran (Iran), und Khulna (Bangladesch).:Preface
Acknowledgment
Abstract
Kurzfassung
Contents
List of Figures
List of Tables
List of Listing
List of Abbreviation
Introduction
1.1. Background of The Research
1.2. The Climate Change Challenge
1.3. Urban Water Systems and Climate Change
1.4. Climate Change and Urban Drainage Adaptation Plan
1.5. Objectives of the Research
1.6. Research Problems and Hypothesis
1.7. Dissertation Structure
1.8. Delimitations
Climate History and Climate Change Projections in Al Hillah City
Chapter One: State of the Art on Climate Change
2.1.1. The Earth’s Climate System
2.1.2. Climate Change
2.1.3. Emission Scenarios
2.1.4. Global Climate Change
2.1.5. Climate Models
2.1.6. Downscaling
Chapter Two: Topography and Climate of the Study Area
2.2.1. Location
2.2.2. Topography
2.2.3. Climate
Chapter Three: Climate Change - Methodology and Data
2.3.1. Methodology
2.3.1.1. Stochastic Weather Generators
2.3.1.2. Description of Generators Used in the Comparison
2.3.1.3. Statistical Analysis Comparison Test
2.3.2. Data
2.3.2.1. Required data for modelling
2.3.2.2. Historical daily data required for the weather generators
2.3.2.3. Minimum requirements
2.3.2.4. Data Availability
Chapter Four: Results Analysis and Evaluation of Climate Change
2.4.1. Weather Generators Comparison Test results
2.4.1.1.The p-value test
Temperature Comparison results
Precipitation Comparison Results
2.4.2. LARS Weather Generator Future Scenario
2.4.2.1.1. Climate Change Scenarios for the region of Babylon governorate
Storm Water System and Urban Flooding in Al Hillah City
Chapter one: Urban Water Modelling
3.1.1. General Overview and Background
3.1.1.1. Storm water systems
3.1.2. Urban Runoff Models
3.1.3. An Overview of Runoff Estimation Methods
3.1.3.1. Computer Modelling in Urban Drainage
3.1.3.2.Statistical Rational Method (SRM)
3.1.4. Models Based on Statistical Rational Method
3.1.5. Urban Rainfall-Runoff Methods
3.1.6. Accuracy Level in Urban Catchment Models
Chapter Two: Urban Water System in Al Hillah City and Data Requirement for Modelling
3.2.1. History
3.2.2. Current Situation
3.2.2.1. Urban water system Iraq
3.2.2.2. Urban Water description in Babylon governorate
3.2.2.3. Drinking water network
3.2.2.4. Sewerage infrastructure
3.2.3. Required data for modelling
Chapter Three: Methodology to Disaggregate Daily Rain Data and Model Storm Water Runoff
3.3.1. Temporal Disaggregation (hourly from daily)
3.3.1.1. Background of Disaggregation
3.3.1.2. Disaggregation techniques
3.3.1.3. DiMoN Disaggregation Tool
3.3.1.4. Input Data
3.3.1.5. Methods Formerly Used
3.3.2. EPA Storm Water Management Model (SWMM)
3.3.2.1. Verification and Calibration
3.3.2.2. Stormwater Management Model PCSWMM
3.3.2.3. Complete support for all USEPA SWMM5 engine capabilities
Chapter Four: Urban Flooding Results
3.4.1. Disaggregation of the daily rain data to hourly data
3.4.1.1.The 1 hour events properties
3.4.1.2. Estimating the rain events in each climate change scenario
3.4.1.3. Past, Current and future return periods
3.4.2. Storm Water Management Model PCSWMM Calibration
3.4.3.Return periods and Urban Floods
3.4.3.1.Network simulation
3.4.3.2.Properties with previous flooding problems
3.4.3.3.Storm water system simulation under 1 hour-2, 5 and 10 years return period
3.4.3.4.Storm water system simulation under 1 hour-25 years return period
3.4.3.5.Storm water system simulation under 1 hour-50 years return period
3.4.3.6. Storm water system simulation under 1 hour – 100, 200, 500 and 1000 years return period
3.4.3.7.Total Flooding
Adaptation Plan for Al Hillah City
Chapter One: International Case Studies
4.1.1. Historical precipitation analysis
4.1.2. Current and projected future climate change, impacts and adaptation plan for each selected city
4.1.2.1. Seattle
4.1.2.2. Odense
4.1.2.3. Tehran
4.1.2.4. Khulna
4.1.2.5. Melbourne
4.1.3. Drainage System of the Studied Cities
4.1.3.1. Drainage System in Seattle
4.1.3.2. Drainage System in Odense
4.1.3.3. Drainage System in Tehran
4.1.3.4. Drainage System in Khulna
4.1.3.5. Drainage System in Melbourne
Chapter Two: Adaptation Plan for Al Hillah City
4.2.1. Conclusions from Adaptation Options Analysed
4.2.2. Suggestions for Al Hillah City
4.2.3. Adaptation Actions
Overall Conclusion
Bibliography
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Omvandla Malmö till en "svampstad"? : En studie om sponge city-konceptet / Transform Malmö into a sponge city? : A study about the sponge city-conceptDracic, Melisa January 2021 (has links)
Förekomsten av vattenrelaterade problem som extrem nederbörd, översvämningar, torka och vattenbrist kommer att öka i urbana områden till följd av de globala klimatförändringarna. Sponge city-konceptet är ett urbant dagvattenhanteringssystem som lanserades i Kina och syftar till att förbättra vattenhanteringen i städer genom att återställa stadens kapacitet att absorbera, infiltrera, lagra och rena vatten. Den här studien syftade till att undersöka om sponge city-konceptet hade kunnat implementeras i Malmö genom att besvara frågeställningen ” Vilka möjligheter respektive hinder finns det för Malmö att implementera sponge city-konceptet?”. Genom en systematisk litteraturstudie och innehållsanalys i kombination med det teoretiska ramverket som baserades på konceptet sårbarhet för klimatförändringar visade resultatet på att det både finns en del möjligheter men också hinder. Det huvudsakliga hindret som identifierades är att en stor del av marken i Malmö består av täta moränleror vilket utgör ett hinder för de infiltrationsåtgärder som ingår i sponge city-konceptet. Några möjligheter som identifierades är att sponge city-konceptet kan minska känsligheten för skada som uppstår i förhållande till exponeringsnivån, samt att Malmös anpassningskapacitet är relativt hög. På grund av att den här studien enbart undersökte specifika fysiska/miljömässiga aspekter inom sponge city-konceptet krävs däremot fler studier som tar hänsyn till fler aspekter om en implementering av konceptet skulle bli aktuell. / The occurrence of water related problems such as extreme precipitation, floods, drought and water scarcity will increase in urban areas as a result of global climate change. The sponge city-concept is an urban stormwater system launched in China and aims to improve the water management in cities by restoring the city’s capacity to absorb, infiltrate, store and purify water. This study aimed to investigate if the sponge city-concept could be implemented in Malmö by answering the question “What possibilities and obstacles exist for Malmö to implement the sponge city-concept?”. Through a systematic literature review and content analysis in combination with the theoretical framework, which was based on the concept climate change vulnerability, the results showed that there are some possibilities but also obstacles. The main obstacle that was identified is that the ground in Malmö largely consists of dense moraines which forms an obstacle for the infiltration measures that are included in the sponge city-concept. Some possibilities that were identified is that the sponge city-concept can decrease the sensitivity to harm that occurs in relation to the exposure level but also that Malmö’s adaptation capacity is relatively high. However, because this study only investigated specific physical/environmental aspects within the sponge city-concept, more studies that consider more aspects are required if an implementation of the concept would become prevailing.
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Föroreningar från gata till å : Utvärdering av beräkningsmetod för föroreningsbelastning från dagvatten genom en fallstudie i Uppsala / Pollutants from Road to River : Evaluation of Computational Method for Pollution Loadfrom Storm Water through a Case Study in Uppsala, SwedenKarlsson, Johan, Öckerman, Hannes January 2016 (has links)
Vi lever i ett samhälle med pågående urbanisering. Nyexploateringar och förtätningar istadsmiljöer bidrar till minskad infiltration och evapotranspiration samt ökad ytavrinning avregn- och smältvatten; så kallat dagvatten. Det är viktigt att kvantifiera denna diffusaföroreningskälla i urbana miljöer då bland annat näringsämnen och tungmetaller transporterasmed dagvattnet, vilket bidrar till försämrad status i recipienter. Enföroreningsbelastningsmodell för näringsämnen i dagvatten på nationell nivå används avSvenska miljöemissionsdata (SMED). Beräkningsmetoden använder empiriskt framtagnaavrinningskoefficienter och belastningsschabloner som varierar beroende påmarkanvändningsslag. Flödesproportionell provtagning av totalhalter kväve, fosfor, bly, koppar, zink, kadmium ochsuspenderad substans genomfördes under nio veckor i ett av Uppsalas störstadagvattenavrinningsområden. Syftet var att kvantifiera områdets föroreningsbelastning för attutvärdera och föreslå förbättringar till SMED:s beräkningsmetod som enligt tidigare studierhar stora osäkerheter, men även för att ge underlag till placering av eventuella reningsåtgärderi området. Provtagningen kompletterades med en modellutvärdering där beräkningsmetodenskänslighet med avseende på markanvändning och inkludering av basflöde testades. Även enmer fysikaliskt förankrad modell för näringsämnestransport i naturliga avrinningsområdenanvändes i modellutvärderingen. Resultaten visade att bly, koppar och zink transporteras till Fyrisån i koncentrationer somöverskrider föreslagna regionala riktvärden för dagvatten. För koppar och zink är även dentotala belastningen på recipient högre än tidigare modellerade värden. Då tungmetaller, menäven fosfor, till stor del transporteras i partikulär form bör en eventuell reningsåtgärd iavrinningsområdet fokusera på att avskilja partikulärt material. Åtgärden bör även placerasuppströms industrin GE Healthcare Bio-Sciences AB där föroreningskoncentrationerna spädsut genom att stora volymer kyl- och regenereringsvatten tillförs dagvattennätet. Vidare visade modellutvärderingen att när SMED:s beräkningsmetod applicerades på detstuderade avrinningsområdet överskattades volymavrinningen från dagvattnet jämfört medprovtagningsresultaten medan medelkoncentrationen för kväve underskattades. För fosfor gavprovtagningsresultaten och beräkningsmetoden samstämmiga svar. Sammantagetöverskattade modellen fosforbelastningen något men underskattade kvävebelastningen. Förkväve har basflödet visat sig stå för en betydande del av belastningen och bör därför iframtiden inkluderas i SMED:s beräkningsmetod. Även den markanvändningskarta somanvänds i metoden bör bytas ut på grund av dess inaktualitet samt att modellutvärderingenvisade relativt stora känsligheter i resultaten för ändring i markanvändning. / We live in a society with an ongoing urbanization. New development projects anddensifications in urban areas contribute to reduced infiltration and evapotranspiration and anincreased surface runoff from rain and melt water, i.e. stormwater. It is essential to quantifythis diffuse source of pollution in urban environments since nutrients, heavy metals and otherpollutants, are transported by the stormwater and contribute to recipient degradation. Anutrient pollution load model in stormwater is used by Swedish environmental emission data(SMED) on a national level. The SMED computational method utilizes empirical runoffcoefficients and standard concentrations, which vary depending on the catchment land-use. Flow proportional sampling of total concentrations of nitrogen, phosphorus, lead, copper,zinc, cadmium and suspended solids was conducted during nine weeks in one of the largeststormwater catchments in Uppsala city, Sweden. The study aimed at quantifying the pollutionload of the catchment in order to evaluate and suggest improvements to the SMEDcomputational method, which contains large uncertainties according to previous studies.Furthermore, the study aimed at providing a basis for potential treatment measures in thecatchment. The sampling was complemented with a model evaluation where the sensitivity ofthe computational method was tested with respect to land-use input and the inclusion ofbaseflow. The model evaluation also included a comparison with a more physically basedmodel for nutrient transport in natural catchments. The results revealed that lead, copper and zinc are discharged into the Fyris River inconcentrations exceeding proposed regional guideline values. For copper and zinc the totalpollution loads on the recipient are higher than previously modeled values. As heavy metalsand phosphorus are transported largely in particulate form the potential treatment measureshould have the ability to effectively separate particulate matter from the stormwater matrix.Due to emissions of large volumes of cooling and regeneration water from the industry GEHealthcare Bio-Sciences AB, the stormwater pollutants are diluted. The treatment measureshould therefore be placed upstream from the industry. When applying the SMED computational method on the studied catchment, the modeloverestimated the runoff volume from stormwater compared to the sampling results, while theaverage nitrogen concentration was underestimated. Regarding phosphorus concentrations,the model and the sampling results concurred relatively well. This resulted in a higherphosphorus, but lower nitrogen, pollution load predicted by the model. It can partly beattributed the fact that baseflow transport of nitrogen is a significant part of the total pollutionload, and should thus be included in the SMED computational method in future calculations.Another model improvement would be to replace the outdated land-use map currently beingused in the method as the model evaluation indicated a relatively large sensitivity in theresults with regards to alterations in the land-use type input.
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THE CHARACTERIZATION AND SURVEY OF INORGANIC SULFUR REDOX ASSOCIATED WITH WETLAND HYDROLOGICAL FLUCTUATIONSBuzulencia, Hayley Catherine 26 November 2019 (has links)
No description available.
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Treatment of dissolved metals in highway runoff water : Pilot-scale trial with four reactive filter media and sand filter / Rening av lösta metaller i dagvatten från motorvägar : Försök i pilotskala med fyra reaktiva filtermaterial och sandfilterBianchi, Serena January 2021 (has links)
The increasing highway traffic is leading to higher and higher levels of pollutants in the stormwater, such as suspended solids, metals, oils, nutrients and PAH. This runoff water causes the degradation of water bodies quality, leading to increased interest in the treatment of highway runoff for the removal of contaminants. Traditional treatments mostly consist of sedimentation, aimed primarily at the removal of suspended solids and particlebound contaminants. Recently the concern has shifted to the dissolved and colloidal fractions of contaminants as well, metals in particular, which makes reactive media filters a potentially interesting technology for runoff water treatment. However, very little research has been carried out on this technology so far, mostly in batch laboratory experiments with synthetic runoff water. This study aims at investigating the performance of four reactive media filters (Petrit T, Polonite, D-Rainclean and Filtralite-P) and a defined filter sand used for water processing at removing dissolved and particulate-bound metals. To achieve the goal, a pilot plant has been constructed in Gröndal, south of Stockholm, inside the existing Gröndalsmagasin, a full-scale stormwater treatment plant. The catchment area is located mostly on the E4 and Essingeleden, the highest trafficked motorway in Sweden with an AADT of 140 000 vehicles. A pump feeds the pilot plant from the Gröndalsmagasin outlet, after the stormwater has been treated with flocculation and sedimentation, and collects such water in a collection vessel. The five filter media columns are fed during runoff events with a flow scaled proportionally to the influent in the Gröndalsmagasin to mimic real conditions of flow and pollutant concentrations. Field measurements of pH, turbidity and conductivity, have been carried out during the trial. Samples have also been collected with flow proportional samplers connected to the collection vessel and the outlet of the five columns, as well as in the form of grab samples from sample ports at different depths in the columns. These samples have been sent to ALS Scandinavia AB to perform lab analysis. The pH in the effluent of the reactive filter media increased to values between 10 and 13, and slowly decreased during the trial. No difference was found between the pH in Filtersand outlet and the influent water. All materials showed excellent performance at removal of dissolved and particulate-bound Zn as well as particulate-bound Cu. Dissolved Cu was removed effectively by reactive media, and to a minor extent by Filtersand. Leaching of metals was observed from three materials: Filtersand released Mn during April, Polonite released Cr, with a very good correlation with the Chloride content and Petrit-T released Ba during the entire trials. / Den ökande vägtrafiken leder till allt högre halter av föroreningar i dagvattnet, till exampel suspenderade ämnen, metaller, oljor, närings ämnen och PAH. Detta dagvatten försämrar degradering av vattenförekomsternas kvalitet, vilket har lett till ett ökat intresse för rening av dagvatten fr ̊ån motorvägar för att avlägsna föroreningar. Traditionella behandlingar består oftast av sedimentering, som främst syftar till att reducera suspenderade ämnen och partikelbundna föroreningar. På senaste tiden har intresset förskjutits till att även omfatta lösta och kolloidala fraktioner av föroreningar, speciellt metaller, vilket gör reaktiva filtermaterial till en potentiellt intressant teknik f ̈or behandling av dagvatten. Mycket lite forskning har dock gjorts om denna teknik hittills, då oftast i laboratorieexperiment med syntetiskt dagvatten. Denna studie syftar till att undersöka hur fyra reaktiva mediafilter (Petrit T, Polonite, D-Rainclean och Filtralite-P) och en typ av sandfilter fungerar när det gäller att avlägsna lösta och partikelbundna metaller. F ̈or att uppnå målet har en pilotanläggning byggts i Gröndal, söder om Stockholm, inuti det existerande Gröndalsmagasinet, ett dagvattenreningsverk i full skala. Avrinningsområdet ligger vid E4 och Essingeleden, den mest trafikerade motorvägen i Sverige med en ÅDT på 140 000 fordon. En pump matar pilotanläggningen fr ̊ån Gröndalsmagasinets utlopp, efter att dagvattnet har behandlats med flockning och sedimentering, och samlas upp detta vatten i ett uppsamlingskärl. De fem filtreringskolonnerna matas under avrinningshändelserna med ett flöde som är proportionellt till inflödet till Gröndalsmagasinet för att imitera verkliga förhållanden av flöde och föroreningskoncentrationer. Mätningar av pH, turbiditet och konduktivitet har utförts under försöket. Prover har också samlats in med flödesproportionella provtagare som är kopplade till uppsamlingskärlet och utloppet fr ̊an de fem kolonnerna, samt i form av grabbprover fr ̊an provtagningsöppningar på olika djup i kolonnerna. Dessa prover har skickats till ALS Scandinavia AB för laboratorieanalys. pH-värdet i utflödet fr ̊ån det reaktiva filtermediet ökade till värden mellan 10 och 13 och sjönk långsamt under försöket. Ingen skillnad hittades mellan pH-värdet i filtrets utlopp och inflödesvattnet. Alla material visade mycket goda resultat när det gäller avlägsnande av löst och partikulät bundet Zn samt partikulärt bundet Cu. Lösta Cu avlägsnades mycket effektivt av reaktiva medier och i mindre utsträckning av Filtersand. Läckage av metaller observerades fr ̊ån tre material: Filtersand släppte ut Mn under April, Polonite släppte ut Cr, med en mycket god korrelation med kloridhalten och Petrit-T släppte ut Ba under hela försöket.
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