Over the past decades, climate change and urbanization have altered the regional hydro-environments, causing a series of stormwater management problems including urban flood and non-point pollution. Low impact development (LID) has been identified as a sustainable strategy for stormwater management. However, given the complex impacts of climate change and urbanization on hydro-environments, the performance of LID strategy under future changes remains largely unexplored. Accordingly, this research characterized the LID performance under changes in climate and urbanization. To provide an additional reference to sustainable stormwater management, the following specific topics were addressed: (1) Through hydraulic and water quality modeling, the LID performances of flood mitigation and pollution removal were systematically evaluated at the city scale. (2) Through uncertainty analysis, the impact of model parameter uncertainty on the LID performance was taken into account. (3) Through sensitivity analysis, the impact of LID technical parameters (e.g., surface features, soil textures) on the LID performance was quantified. (4) Through scenario analysis, the LID performances under different hydrological patterns were compared. (5) Through spatial analysis, the distribution of LID performance on different land-cover types was determined. (6) Through adopting general circulation model (GCM) projections, the LID performance under future climate scenarios with different representative concentration pathways (RCPs) was investigated. (7) Through adopting integrated assessment model (IAM) projections, the LID performance under future urbanization scenarios with different shared socioeconomic pathways (SSPs) was explored. (8) By coupling climate and urbanization projections with land-cover distribution, the spatiotemporal trends of LID performance in the future were characterized.:Table of Contents List of Abbreviations VII List of Peer-Reviewed Publications on the Ph.D. Topic IX List of Co-authored Peer-Reviewed Publications on the Ph.D. Topic X 1 General Introduction 1 1.1 Background 1 1.2 Objectives 3 1.3 Innovation and Contribution to the Knowledge 3 1.4 Outline of the Dissertation 4 1.5 References 5 2 Literature Review 9 2.1 Hydraulic and Water Quality Modeling 9 2.1.1 Hydraulic Model 9 2.1.2 Water Quality Model 10 2.2 Low Impact Development (LID) 10 2.2.1 LID Practice 10 2.2.2 LID Performance 11 2.3 Performance Evaluation 13 2.3.1 Scenario Analysis 13 2.3.2 Spatial Analysis 13 2.3.3 Uncertainty Analysis 14 2.3.4 Sensitivity Analysis 14 2.4 Future Changes in Climate and Urbanization 15 2.4.1 Climate Change 15 2.4.2 Future Urbanization 16 2.5 References 17 3 Impact of Technical Factors on LID Performance 27 3.1 Introduction 28 3.2 Methods 30 3.2.1 Study Area 30 3.2.2 Model Description 31 3.2.2.1 Model Theory 31 3.2.2.2 Model Construction 31 3.2.2.3 Model Calibration and Validation 32 3.2.2.4 Model Uncertainty Analysis by GLUE Method 34 3.2.3 Hydrological Pattern Design 35 3.2.4 LID Strategy Design 35 3.2.4.1 Implementation of LID Practices 35 3.2.4.2 Sensitivity Analysis by Sobol’s Method 36 3.2.5 Correlation Analysis Using a Self-Organizing Map 37 3.2.6 Description of the RDS Load Components 37 3.3 Results 38 3.3.1 RDS Migration and Distribution in Baseline Strategy 38 3.3.1.1 RDS Migration under Hydrological Scenarios 38 3.3.1.2 RDS Distribution on Land-Cover Types 39 3.3.2 RDS Removal in LID Strategies 40 3.3.2.1 RDS Removal by LID Strategies 40 3.3.2.2 Spatial Distribution of the RDS Removal 42 3.3.2.3 LID Parameter Sensitivity Analysis Result 43 3.4 Discussion 45 3.4.1 Factors Influencing RDS Migration in the Baseline Strategy 45 3.4.2 RDS Removal Performance by LID Strategy 46 3.5 Conclusions 47 3.6 References 47 4 Impact of Hydro-Environmental Factors on LID Performance 53 4.1 Introduction 54 4.2 Methods 56 4.2.1 Study Area 56 4.2.2 Modeling Approach 56 4.2.2.1 Model Theory 56 4.2.2.2 Model Construction 56 4.2.2.3 Model Calibration and Validation 57 4.2.2.4 Model Uncertainty Analysis 57 4.2.3 LID Performance Analysis 58 4.2.3.1 LID Practice Implementation 58 4.2.3.2 LID Performance Evaluation 58 4.2.4 Hydrological Pattern Analysis 59 4.2.4.1 Scenario of ADP Length 59 4.2.4.2 Scenario of Rainfall Magnitude 59 4.2.4.3 Scenario of Long-Term pre-Simulation 60 4.2.5 Sensitivity Analysis of Hydrological Scenarios 60 4.3 Results 61 4.3.1 LID Performance under Different ADP Lengths 61 4.3.2 LID Performance under Different Rainfall Magnitudes 62 4.3.3 Spatial Distribution of LID Performance 63 4.3.4 Sensitivities of LID Performance to ADP Length and Rainfall Magnitude 66 4.4 Discussion 68 4.4.1 Impact of ADP Length and Rainfall Magnitude on LID Performance 68 4.4.2 Spatial Heterogeneity of LID Performance 68 4.4.3 Research Implications 69 4.5 Conclusions 70 4.6 References 71 5 Impact of Future Climate Patterns on LID Performance 77 5.1 Introduction 78 5.2 Methods 80 5.2.1 Study Area 80 5.2.2 Hydraulic and Water Quality Model 80 5.2.2.1 Model Development 80 5.2.2.2 Model Calibration and Validation 81 5.2.3 Climate Change Scenario Analysis 81 5.2.3.1 GCM Evaluation 81 5.2.3.2 Greenhouse Gas (GHG) Concentration Scenario 82 5.2.3.3 GCM Downscaling 83 5.2.4 LID Performance Analysis 83 5.2.4.1 Implementation of LID Practices 83 5.2.4.2 Evaluation of LID Performance 84 5.2.4.3 Sensitivity Analysis on LID Performance 86 5.3 Results 86 5.3.1 Hydrological Characteristics under Future Climate Scenarios 86 5.3.2 LID Performance under Future Climate Scenarios 87 5.3.2.1 LID Short-Term Performance 87 5.3.2.2 LID Long-Term Performance 90 5.3.3 Impact of ADP Length and Rainfall Magnitude on LID Performance 92 5.3.3.1 LID Performance Uncertainty 92 5.3.3.2 Spatial Distribution of LID Performance 93 5.3.3.3 Sensitivity of LID Performance to Climate Change 95 5.4 Discussion 97 5.4.1 LID Performance in Short-Term Extremes and Long-Term Events 97 5.4.2 Impact of Climate Change on LID Performance 97 5.4.3 Research Implications 99 5.5 Conclusions 100 5.6 References 100 6 Impact of Climate and Urbanization Changes on LID Perfor-mance 109 6.1 Introduction 110 6.2 Methods 112 6.2.1 Study Area 112 6.2.2 Modeling Approach 112 6.2.2.1 Model Development 112 6.2.2.2 Model Calibration and Validation 113 6.2.3 Future Scenario Derivation 113 6.2.3.1 Climate Change Scenario 113 6.2.3.2 Urbanization Scenario 115 6.2.4 Flood Exposure Assessment 115 6.2.5 Implementation and Evaluation of LID Strategy 117 6.2.5.1 Implementation Scheme of LID Strategy 117 6.2.5.2 Performance Evaluation of LID Strategy 117 6.3 Results 118 6.3.1 Flood Exposure in Baseline and Future Scenarios 118 6.3.1.1 Hydrological Change in Future Climate Scenarios 118 6.3.1.2 Catchment Change in Future Urbanization Scenarios 118 6.3.1.3 Population and GDP Exposures to Flood in Future 121 6.3.2 Flood Exposure with Consideration of LID Strategy 123 6.3.2.1 Runoff Mitigation Performance of LID Strategy 123 6.3.2.2 Peak Mitigation Performance of LID Strategy 124 6.3.2.3 Population and GDP Exposures to Flood under LID Strategy 125 6.4 Discussion 126 6.4.1 Climate Change and Urbanization Exacerbated Flood Exposure Risk 126 6.4.2 LID Strategy Mitigated Flood Exposure Risk 126 6.5 Conclusions 127 6.6 References 127 7 Discussion and General Conclusions 133 7.1 Stormwater Management Performance of LID Strategy 133 7.2 Impact of Influencing Factors on LID Performance 134 7.3 LID Performance under Future Changes 135 7.4 Research Implications 136 7.5 References 137 8 Outlook of Future Research 139 8.1 Optimization of LID Performance 139 8.2 Cross-regional Study on Future Changes 139 8.3 Macro-scale Flood Risk Management 140 8.4 References 141 9 Appendices 143 9.1 Appendix for Chapter 3 143 9.1.1 The Determination of the GLUE Criteria 143 9.1.2 Model Uncertainty Analysis 143 9.1.3 The LID Installation Location 144 9.1.4 Figures 145 9.1.5 Tables 147 9.2 Appendix for Chapter 4 153 9.2.1 Scenario of Long-term pre-Simulation 153 9.2.2 Figures 153 9.2.3 Tables 158 9.3 Appendix for Chapter 5 164 9.3.1 Tables 164 9.4 Appendix for Chapter 6 169 9.4.1 Figures 169 9.4.2 Tables 170 9.5 Data Source 177 9.6 References 178

Sustainable Built Environments Senior Capstone Project / During Tucson rainstorms, many roads and neighborhoods experience high levels of flooding on the city’s street networks. This phenomenon creates unsafe road conditions, damage to the road infrastructure, and excessive urban stormwater runoff that is potentially polluted. The vast quantities of impervious surfaces in the urban landscape impede the rainwater’s ability to infiltrate the ground, thus resulting in increased volumes of runoff during a rainstorm. Stormwater management is used by municipalities and communities to address the previously mentioned adverse impacts of stormwater runoff. Various techniques and strategies used in stormwater management include, low impact development (LID), green infrastructure, and better site design (BSD) strategies implemented during design stages to reduce stormwater runoff levels. In addition, local governments can establish stormwater utilities and policies in order to help address and better manage the issue of stormwater runoff within urban areas. The primary research questions of this study will include: What are the most effective best management practices and techniques to address urban runoff? What combination of best management practices and government policies will be the more effective in addressing Tucson’s urban runoff problem? Accordingly, this study will examine a variety of policies and techniques to address stormwater runoff, and then, based on this information, provide a suggestion of the best practices and techniques that may be feasible for implementation in Tucson.

Sustainable Built Environments Senior Capstone Project / During Tucson rainstorms, many roads and neighborhoods experience high levels of flooding on the city’s street networks. This phenomenon creates unsafe road conditions, damage to the road infrastructure, and excessive urban stormwater runoff that is potentially polluted. The vast quantities of impervious surfaces in the urban landscape impede the rainwater’s ability to infiltrate the ground, thus resulting in increased volumes of runoff during a rainstorm. Stormwater management is used by municipalities and communities to address the previously mentioned adverse impacts of stormwater runoff. Various techniques and strategies used in stormwater management include, low impact development (LID), green infrastructure, and better site design (BSD) strategies implemented during design stages to reduce stormwater runoff levels. In addition, local governments can establish stormwater utilities and policies in order to help address and better manage the issue of stormwater runoff within urban areas. The primary research questions of this study will include: What are the most effective best management practices and techniques to address urban runoff? What combination of best management practices and government policies will be the more effective in addressing Tucson’s urban runoff problem? Accordingly, this study will examine a variety of policies and techniques to address stormwater runoff, and then, based on this information, provide a suggestion of the best practices and techniques that may be feasible for implementation in Tucson.

Houston's Fifth Ward neighborhood is one of the last remaining areas of the inner city to have not yet seen large-scale redevelopment. Situated just northeast of downtown, the neighborhood's population is predominantly low- to mid-income African Americans; demographics are similar today as they were during the neighborhood's prime, from the 1920s-60s, when the Fifth Ward was a cultural hub of Houston famous for its musical culture of zydeco and blues. The ward's rich history also has dark spots, however, specifically its longstanding reputation as a center of poverty and violent crime, and its physical vulnerability to damaging floods. Much of the neighborhood's built history is unpreserved and unprotected, at risk of being wiped off the map by both development interests and extreme weather events. By modernizing the city's approach to stormwater management and infrastructure and strengthening its historic preservation and emergency management practices, Houston could help preserve one of its oldest communities, while also decreasing flood volumes, improving air and water quality, saving money, and establishing a pattern of smart growth citywide. In addition, neighborhood level efforts to promote placemaking via preservation and sustainability efforts can help the Fifth Ward leverage the redevelopment process to change its reputation, ensuring a future for the community that respects its past. / text

Stormwater runoff is one of the leading causes of water quality impairment in the U.S. Bioretention systems are ecologically engineered to treat stormwater pollution and offer exciting opportunities to provide local climate change resiliency by reducing peak runoff rates, and retaining/detaining storm volumes, yet implementation is outpacing our understanding of the underlying physical, biological, and chemical mechanisms involved in pollutant removal. Further, we do not know how performance will be affected by increases in precipitation, which are projected to occur in the northeastern U.S. as a result of climate change, or if these systems could act as a source or sink for greenhouse gas emissions. This research examines the design, construction, and development of monitoring methods for bioretention research, using the University of Vermont (UVM) Bioretention Laboratory as a case study. In addition, this research evaluates mobilization patterns and pollutant loads from road surfaces during the "first flush" of runoff, or the earlier part of a storm event. Finally, this research analyzes the comparative pollutant removal performance of bioretention systems on a treatment by treatment basis. At the UVM Bioretention Laboratory, eight lined bioretention cells were constructed with monitoring infrastructure installed at the entrance and at the subterranean effluent. A conventional, sand and compost based, bioretention soil media was compared to a proprietary media engineered to remove phosphorus, called Sorbtive Media™, under simulated increases in precipitation. Two drought tolerant vegetation mixes, native to the northeast, were compared for sediment and nutrient retention. Each treatment was sampled for soil gas emissions to determine if it was a source or a sink. The monitoring infrastructure designs used in this research allowed for the effective characterization of pollutant mass loads entering and exiting bioretention. Cumulative mass loads from stormwater were found to be highest for total suspended solids, followed by total Kjeldahl nitrogen, nitrate, non-labile phosphorus and soluble reactive phosphorus, in descending order by mass. Total suspended solids, total Kjeldahl nitrogen, and non-labile phosphorus mass were well retained by all bioretention treatments. However, the compost amendment in the conventional soil media was found to release labile nitrogen and phosphorus, far surpassing the mass loads in stormwater. When compared with conventional media, Sorbtive Media™ was highly effective at removing labile phosphorus and was also found to enhance nitrate removal. Systems containing deep-rooted vegetation (Panicum virgatum) were found to be particularly effective at retaining both labile and non-labile constituents. Overall, none of the bioretention treatments were found to be a significant source of N2O and were small sinks for CH4 in most treatments.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Tim Keane / Climate change and declining ecological health of urban environments are global issues of growing concern. In order to mitigate these issues we must reduce Greenhouse Gas emissions and increase green infrastructure solutions. One way of doing this is through improving public transportation and decreasing parking areas. In this study, Manhattan, Kansas was used to illustrate how improvements to public transportation can reduce parking demand and to show how excess parking can be transformed into green space to improve the ecological health of the city. First a review of literature and case studies related to increasing ridership of public transportation, reducing parking demand, and calculating ecologic and economic benefits was done. Then ArcGIS was used to analyze the existing public transportation in Manhattan, Kansas. Improvements to the existing transit system were developed and potential increase in ridership was calculated. ArcGIS was then used to analyze existing parking in Manhattan, Kansas. Excess Parking was determined based on current parking demand and predicted transit ridership. A suitability study was then done in ArcGIS to determine which parking areas should be converted into green space. The suitability map assisted in choosing four specific parking areas to redesign in detail to incorporate additional green space and tree cover. It was estimated that improving Manhattan’s bus system could double its ridership. It was also estimated that with improved public transit and parking planning, 30% of Manhattan’s parking could be eliminated. Converting 30% of Manhattan’s parking into green space would decrease runoff and pollutants from parking lots. Ecological valuation methods were used to calculate the benefits of converting parking into green space. It was found that integrating green space into parking lots would decrease stormwater runoff, mitigate the heat island effect, store carbon, improve air quality and may have social benefits as well.

Low impact developments (LID) have been used to mitigate the effects of urbanization on the hydrological cycle. However, there is a lack of studies on LID performance in subtropical climates and under potential impacts of climate change scenarios. This dissertation evaluated the impacts of two climate change scenarios (RCP 4.5 and 8.5) on urban drainage with pollutants and their effect on LID practice efficiency located in a subtropical climate, with Cfa classification according to Köppen and Geiger. First, the inlet quantity and quality parameters were calibrated. The buildup/washoff model was evaluated, comparing load calibration and concentration of pollutants: chemical oxygen demand (COD), total organic carbon (TOC), phosphate (PO4) (NH3), iron (Fe), cadmium (Cd) and zinc (Zn). Pollutant washing was studied in the area of the bioretention catchment using historical rainfall data between 2013 and 2017, analyzing the influence of the buildup/washoff parameters of each pollutant in the input mass. Afterwards, Eta5x5km (INPE) climate change scenarios were disaggregated to 5-minute intervals by the modified Bartlett-Lewis method. The disaggregated series was used to estimate the impacts of climate change on urban drainage into the bioretention. Therefore, a simple model, developed specifically for the study bioretention cell, was used to estimate the qualitative-quantitative efficiencies of each period of the climate change scenarios. According to the data acquired from INPE, climate change will result in a fall in the volume of rainfall in São Carlos, resulting in lower volumes of surface runoff. The impacts on pollutant washing, however, vary according to the buildup/washoff parameters, explained by a sensitivity analysis. Climate change does not affect the bioretention quantitative efficiency very much: 81.7% from 1980 to 1999 to 81.4% and 81.3% from 2080 to 2099 for CPR scenarios 4.5 and 8.5. The pollutant removal efficiencies, as well as the washing, depend on buildup/washoff characteristics. One of the main consequences of climate change is a drop in the runoff quality. However, even with quantitative efficiency being maintained, bioretention is capable of mitigating this increase in the concentration of pollutants in urban drainage. Thus, the LID will help preserve the quality of downstream rivers, whose volumes will already have diminished by the decrease in rainfall volume. / Técnicas compensatórias de drenagem (TC) vêm sido utilizadas para mitigar efeitos da urbanização no ciclo hidrológico. Entretanto faltam estudos sobre a performance destas TCs em clima subtropical e sob potenciais impactos de cenários de mudanças climáticas. Esta dissertação avaliou os impactos de dois cenários de mudanças climáticas (RCP 4.5 e 8.5) sobre o escoamento superficial urbano com poluentes e sua afetação na eficiência da TC localizada em clima subtropical, classificação Cfa segundo Köppen e Geiger. Primeiro se calibrou os parâmetros de quantidade e qualidade do escoamento superficial na entrada da biorretenção. O modelo buildup/washoff foi avaliado, comparando-se calibração da carga e concentração de poluentes: demanda química de oxigênio (DQO), carbono orgânico total (TOC), fosfato (PO4), nitrato (NO3), nitrito (NO2) amônia (NH3), ferro (Fe), cadmio (Cd) e zinco (Zn). Então se estudou a lavagem de poluentes na área de contribuição da biorretenção com histórico de precipitação entre 2013 e 2017 e analisando a influência dos parâmetros buildup/washoff de cada poluente na entrada de massa. Em seguida, cenários de mudanças climáticas Eta-5x5km (INPE) foram desagregados em intervalos de 5 minutos, pelo método de Bartlett-Lewis modificado. A série desagregada foi utilizada para se estimar os impactos das mudanças climáticas na drenagem urbana, a incidir na biorretenção. Então um modelo simples desenvolvido especificamente para a biorretenção em estudo foi usado para se estimar as eficiências quali-quantitativas de cada período dos cenários de mudanças climáticas. Os dados adquiridos do Inpe mostram que as mudanças climáticas resultarão em uma queda no volume de chuvas em São Carlos, resultando em menores volumes de escoamento superficial. Os impactos na lavagem de poluentes, entretanto, variam de acordo com os parâmetros buildup/washoff, explicados por uma análise de sensibilidade. As mudanças climáticas pouco afetam a eficiência quantitativa da biorretenção, 81.7% no período 1980-1999 para 81.4% e 81.3% no período 2080-2099 para cenários RCP 4.5 e 8.5. Já as eficiências de remoção de poluentes, assim como a lavagem destes, dependem das características buildup/washoff de lavagem. Uma das principais consequências observadas das mudanças climáticas é uma queda na qualidade do escoamento. Porém, mesmo com eficiência quantitativa sendo mantida, a biorretenção é capaz de amenizar essa o aumento na concentração de poluentes na drenagem urbana. Assim, a técnica ajudará a preservar a qualidade dos rios à jusante, que já terão seus volumes diminuídos pela queda no volume de chuva.

A urbanização acelerada das últimas décadas aliada à ocupação desordenada e intensa impermeabilização do solo, têm agravado as cheias nas cidades brasileiras. Na cidade de São Paulo, recentemente, os períodos chuvosos, entre os meses de outubro e março, de 2009-2010 e 2010-2011 foram especialmente relevantes, quando ocorreram precipitações intensas e de longa duração que causaram grandes inundações e alagamentos por toda a cidade. Outro agravante é a continuidade da utilização única e exclusivamente de técnicas clássicas com enfoque higienista para a solução dos problemas de drenagem urbana, como é o caso das canalizações dos córregos e rios. Diante dessa problemática surge uma nova abordagem do tema que envolve o manejo sustentável das águas pluviais por meio da utilização de um conjunto de medidas de controle da fonte, que podem ser integradas aos sistemas de drenagem existentes. Essas medidas se baseiam na retenção e infiltração das águas pluviais e na retenção de poluentes, reduzindo a probabilidade de inundações e contribuindo para a melhoria da qualidade da água dos sistemas hídricos urbanos. O objetivo deste estudo foi avaliar, por meio da modelagem matemática, o efeito que a implantação de medidas controle na fonte pode proporcionar no abatimento dos picos de cheia em áreas urbanas densamente ocupadas. Para tanto foi selecionada a bacia do córrego da Luz localizada no centro da cidade de São Paulo que apresenta altas taxas de impermeabilização do solo. As análises foram feitas com o PCSWMM, que é um sistema de suporte a decisão espacial desenvolvido pela CHI para o SWMM5 da EPA. Foram selecionadas medidas de controle na fonte que possam se adequar em locais onde a disponibilidade de espaço é pequena, como é o caso dos pavimentos permeáveis, telhados verdes e jardins de chuva. Os cenários analisados consideraram a situação atual sem implantação de medidas de controle e a implantação individual e combinada das medidas de controle na fonte. São avaliados eventos de precipitações, considerando diferentes períodos de retorno e durações de chuva e a porcentagem de área impermeável contribuinte para as medidas de controle. Uma análise geral dos resultados da modelagem permite apontar que o amortecimento dos picos de cheia foi verificado em todos os cenários, em maior ou menor intensidade, e o melhor desempenho no abatimento do pico de cheia foi verificado nos cenários que consideraram a implantação de pavimentos permeáveis. Os resultados da modelagem e os baixos custos de implantação dos pavimentos permeáveis sugerem que esta medida, dentre as três analisadas, é a que apresenta melhor custo-benefício. Contudo sabe-se que a implantação de pavimento asfáltico permeável em 100% da área disponível pode não ser viável. Logo a implantação conjunta com outras medidas de controle pode melhorar o desempenho de um sistema de controle de cheias. / The accelerated urban growth in the last decades associated with a disordered occupation and excessive impervious surfaces has worsened the floods in Brazilian cities. In the City of São Paulo, lately, the rainy season between October and March, in 2009-2010 and in 2010-2011, were especially relevant. There were intense and long-lasting rainfalls that caused flooding all over the city. Another aggravating factor is the single and exclusive use of traditional stormwater management methods for solving urban drainage problems, which is the case of stream and river canalizations. When faced with these problems, a new approach that involves the sustainable management of rainwater starts growing. These techniques include a set of low impact development practices that should be incorporated to the existing drainage systems. They are based on the detention and infiltration of stormwater, also the retention of pollutants. They also contribute to decreasing flood probability and to improving water quality of urban water systems. The goal is to evaluate, through a mathematical modeling, the low-impact development practices effect on reducing the peak runoff rates in highly urbanized areas. To this end, a subcatchment located in the center of São Paulo city, called Córrego da Luz, was chosen. This subcatchment has high rates of soil imperviousness. The analysis will be made with the PCSWMM, which is a spatial decision support system for the SWMM5 from EPA. The PCSWMM was developed by CHI. The low-impact development techniques selected for this study are permeable pavements, green roofs and rain gardens. These techniques can be implemented in places where space is no longer available. The scenarios must consider the current situation without the implementation of control measures, the individual and combined implementation of these practices. Various rainfall events were evaluated considering different durations. Also evaluated were the different percentages of impervious areas treated by low-impact development techniques. An overview of modeling results allows stating that the reduction of peak runoff was observed in all the scenarios, at greater or lower intensity. But the best performance was observed in scenarios that considered the implementation of permeable pavements. Modeling results and low-cost implementation of permeable pavements suggest that it is the most cost-effective measure, among the three analyzed. However, it is known that the implementation of permeable pavement in 100% of the available area may not be feasible. Hence, the combined implementation with other low-impact developments might improve the performance of a flood control system.

Les ouvrages de biofiltration, systèmes végétalisés conçus pour le stockage, la filtration et éventuellement l’infiltration de l’eau, peuvent contribuer à une meilleure maîtrise du flux polluant associé au ruissellement de voirie. La capacité de ce type de système à réduire les flux de macropolluants, tels que les matières en suspension (MES) et les nutriments, via une amélioration de la qualité de l’eau combinée à une réduction de son volume, est avérée. Cependant, le comportement de micropolluants dans ces systèmes reste relativement peu documenté. Ce travail de thèse s’intéresse donc à la rétention et le devenir de micropolluants dans un système de biofiltration des eaux de voirie. Il s’articule principalement autour du suivi in situ d’un panel diversifié de micropolluants caractéristiques des eaux de voirie (éléments traces métalliques ou ETM, hydrocarbures totaux, hydrocarbures aromatiques polycycliques ou HAP, BPA, alkylphénols, phatalates) et d’indicateurs globaux dans un accotement filtrant et une noue filtrante, situés en bordure d’une route départementale. Ce suivi comporte des mesures débit métriques et de qualité d’eau en continu, un travail d’échantillonnage et d’analyse du ruissellement brut et des eaux traitées par les deux ouvrages (dix-neuf événements pluvieux étudiés au cours d’un an et demi) et un travail d’échantillonnage et d’analyse du sol. Cette démarche est couplée à une caractérisation du substrat filtrant et des matériaux de construction en laboratoire et à une approche de modélisation stochastique pour évaluer le bilan de masse annuel de polluants dans la noue filtrante. Ce suivi démontre la capacité de la biofiltration à réduire de façon significative les concentrations totales en micropolluants à l’échelle de l’événement pluvial. Le traitement est particulièrement efficace pour les contaminants associés majoritairement aux MES, tels que le Zn, le Pb et les HAP pour lesquels la réduction médiane des concentrations événementielles (EC50) est supérieure à 90% dans les deux ouvrages. Pour le Cu, le Cr, le Ni et l’OP, les EC50 sont bonnes, supérieures à 70%. L’efficacité est moindre et plus variable pour les autres micropolluants organiques. Trois événements, caractérisés par une performance dégradée vis-à-vis des MES et des polluants particulaires, ont néanmoins été observés lors de l’application du sel de déverglaçage en hiver. La nature des particules indique que ce comportement soit dû à une mauvaise filtration de particules issues de la route, probablement liée à l’abondance exceptionnelle de particules fines (<10 µm) dans les eaux de voirie pendant cette période, combiné à une fissuration du substrat filtrant, menant à des écoulements préférentiels. La rétention de la phase dissoute des micropolluants est généralement moins efficace que celle de la phase particulaire ; des concentrations élevées ont notamment été observées pour certains micropolluants dissous (BPA, alkylphénols, phtalates) en sortie de la noue filtrante pendant les premiers mois de fonctionnement. Le transport des ETM dissous semble être facilité par leur association avec le carbone organique dissous ; ils sont aussi susceptibles d’être lixiviés à partir du sol contaminé ou des particules issues de la route. La rétention des micropolluants organiques dissous est limitée essentiellement par la contamination du substrat filtrant, dont l’origine est soit antérieure à son installation dans le biofiltre (cas des HAP), soit liée à des émissions de polluants depuis les matériaux de construction (cas probable pour BPA, OP, NP, DEHP).L’établissement du bilan de masse à l’échelle annuelle montre que l’abattement du flux polluant annuel est plus faible que l’EC50, du fait d’une surverse fréquente de l’ouvrage. Il met aussi en évidence l’ampleur des émissions de certains micropolluants organiques depuis les matériaux de construction de l’ouvrage, qui dépassent largement le flux polluant intercepté au cours de la première année / Biofiltration is a technique based on vegetated systems for the temporary storage, filtration and possible infiltration of runoff water close to the source, which may be used to manage pollutant loads associated with road runoff. The ability of this type of system to reduce loads of macropollutants, such as suspended solids and nutrients, both through the improvement of water quality and the reduction of its volume, has been established previously. However, the behavior of micropollutants in these systems remains relatively uncharacterized. The objective of the present work is to evaluate the retention and fate of micropollutants in a biofiltration system treating road runoff. It is principally focused on the in situ monitoring of a wide range of micropolltuants typical of road runoff (trace metals or TMs, total petroleum hydrocarbons, polycyclic aromatic hydrocarbons or PAHs, alkylphenols, BPA, phtalates) and global water quality parameters in two biofiltration systems located beside a highway: a vegetative filter strip and a biofiltration swale. This work involves continuous flow and water quality measurements, the sampling and analysis of runoff and infiltrated water drained from both systems (nineteen rain events over a year-and-a-half period) as well as the sampling and analysis of soil. These results are combined with a laboratory characterization of the filter media and biofilter construction materials and a stochastic modeling approach used to evaluate the annual mass balance of pollutants in the biofiltration swale. Field results highlight the ability of biofiltration to significantly reduce total concentrations of micropollutants at the event scale. Treatment is particularly effective for contaminants mainly associated with suspended solids, such as Zn, Pb and PAHs, for which median concentration reductions (EC50) exceeded 90% in both systems. EC50 observed for Cu, Cr, Ni and OP are also quite good, exceeding 70%. Treatment efficiency is lower and more variable for the other organic micropollutants. Three events, characterized by a degraded performance with respect to suspended solids and particulate pollutants, were, however, observed during a winter period when deicing salt was applied to road surfaces. Particle characteristics indicate that this behavior was due to the poor filtration of road-originated particles, probably due to an exceptional abundance of fine particles (<10 µm) in the road runoff during this period, in combination with the formation of preferential flows in the filter media due to cracking. The retention of dissolved-phase micropollutants is generally less effective than that of the particulate phase; in particular, elevated dissolved concentrations of several micropollutants (BPA, alkylphenols, phthalates) were observed during the first months of operation of the biofiltration swale. The transport of dissolved TMs appears to be facilitated by their association with dissolved organic carbon. These contaminants may also be leached from contaminated soil and road sediments. The retention of dissolved organic micropollutants is essentially limited by filter media contamination, which predates installation in the biofilter for PAHs and is attributed to pollutant emissions from construction materials for BPA, OP, NP and DEHP.In order to evaluate the systems’s ability to reduce pollutant loads and characterize the fate of pollutants in the filter media, a mass balance is evaluated at the annual scale for a selection of micropollutants. This work reveals that the reduction of pollutant loads is generally lower than the EC50 observed at the event scale due to the frequent overflow of water from the device. It also shows the significance of organic micropollutant emissions from biofiltration swale construction materials, which were much greater than the pollutant loads intercepted over the first year of operation

Conscious Living is a series of visual solutions to a current and escalating problem in increasingly populated modern societies between its citizens and the environment they inhabit. Documented in the photographs are two dissimilar intentional communities that both strive to operate harmoniously with the surrounding ecology. Originally intending to address the misconception that low impact living is uncomfortable or unsatisfying, this research and my firsthand experience has led to conclusions that are more complex and less didactic. Although the images focus on these two communities, ultimately the intention is to provide the viewer with new perspectives on these niche groups, as well as options to implement low impact alternatives to their lifestyle.