Multiobjective Planning and Design of Distributed Stormwater Harvesting and Treatment Systems through Optimization and Visual Analytics

Stormwater harvesting (SWH) is an important water sensitive urban design (WSUD) approach that provides an alternate water source and/or improves runoff quality through stormwater best management practice technologies (BMPs). Through integrated SWH system design at the development scale practitioners must account for trade-offs between cost, harvested volume, and water quality improvement performance which are usually dependent on design decisions for the type, size, and spatial distribution of BMPs. In catchment management planning, additional objectives such as catchment vegetation improvement and public recreation benefit need to be maximized for a catchment region within a limited budget. As such, planning and design of SWH systems with distributed BMPs is a complex problem that requires optimal allocation of limited resources to maximize multiple benefits. In this thesis, two innovative formal optimization approaches are presented for formulating and identifying optimal solutions to problems requiring distributed BMPs. Firstly, a multiobjective optimization framework is presented and applied to a case study for the conceptual design of integrated systems of BMPs for stormwater harvesting. The aim of this work is to develop a conceptual design modelling framework that handles the optimal placement of stormwater harvesting (SWH) infrastructure within an urban development. The framework produces preliminary SWH system designs representing optimal trade-offs between cost, water harvesting, and water quality improvement measures. Secondly, a many (>3) -objective optimization framework is presented and applied to a case study for catchment planning requiring the selection of a portfolio of distributed BMP projects. The framework produces portfolios that are optimal with respect to four objectives, and enables exploration of the many-objective trade-off surface using interactive visual analytics. In addition, a multi-stakeholder method is presented, which enables catchment managers and local government authorities to identify solutions that represent a compromise between 16 objectives and eight optimization problem representations using interactive visual analytics to encourage a negotiated solution. This thesis contains one paper accepted in the Journal of Water Resources Planning and Management (Paper 1), and one paper submitted (Paper 2), and one paper to be submitted (Paper 3) to peer-reviewed journals in the field of water resources management.Thesis (Ph.D.) -- University of Adelaide, School of Civil, Environmental & Mining Engineering, 201

Stormwater Management Adaptation Pathways under Climate Change and Urbanization

Urban runoff volumes and flow peaks are likely to increase in the future owing to climate change-driven effects on rainfall and continued urbanization. Actionable planning estimates that anticipate these impacts are needed to assess stormwater management infrastructure requirements and to minimize impacts on ecosystem services. This study presents a planning-level simple flow simulation tool and quantifies benefits of green stormwater management practices in small watersheds. Flow simulation was performed using a curve number-based watershed model (CWM). A portfolio approach was used to assess cost-optimal stormwater adaptation pathways considering a suite of alternative practices including both gray and green infrastructure. The CWM provides actionable information for medium to highly urbanized watersheds with percent bias less than 30% for highly urbanized watersheds. Considering projected future stormwater needs, analysis of multiple stormwater management approaches showed that green stormwater management alternatives are less cost-optimal than gray infrastructure at small watershed scales. These results suggest the possible use of CWM for quick planning-level flow estimates and analysis of more green practices for cost-optimal alternatives

Climate-Smart Stormwater Management

Increased precipitation and risk of flooding are major effects due to climate change that Swedish municipalities need to consider, while facing an ongoing growth in population and densification of urban areas. In this context, urban stormwater management represents a growing challenge. The vulnerability of the society towards climate change depends on the capability of the city to responds to environmental issues.This report presents the challenges and the needs for the implementation of sustainable stormwater solutions encountered in the urban planning process for the city of Gothenburg. The decision making process can be facilitated by the adoption of a stormwater toolbox, which functionalities are designed to support the stakeholders at each step of the planning process. The modules of the toolbox should be designed around a collaboration platform that assists with transparent information flows and allocation of responsibilities. The specific modules (e.g. hydrology, cost-benefit analysis, experience database) should support the needs along the different phases in the process.This study was financially supported by Climate KIC. The Knowledge and Innovation Communities (KICs) are partnerships set up by the European Institute of Innovation and Technology, EIT, that bring together businesses, research centers and universities with the purpose of developing innovative products and services, starting new companies and training a new generation of entrepreneurs. EIT Climate-KIC\u27s mission is to bring together, inspire and empower a dynamic community to build a zero carbon economy and climate resilient society and to enable Europe to lead the global transformation towards sustainability

Addressing challenges of urban water management in Chinese sponge cities via nature-based solutions

Urban flooding has become a serious issue in most Chinese cities due to rapid urbanization and extreme weather, as evidenced by severe events in Beijing (2012), Ningbo (2013), Guangzhou (2015), Wuhan (2016), Shenzhen (2019), and Chongqing (2020). The Chinese “Sponge City Program” (SCP), initiated in 2013 and adopted by 30 pilot cities, is developing solutions to manage urban flood risk, purify stormwater, and provide water storage opportunities for future usage. Emerging challenges to the continued implementation of Sponge Cities include (1) uncertainty regarding future hydrological conditions related to climate change projections, which complicates urban planning and designing infrastructure that will be fit for purpose over its intended operating life, and (2) the competing priorities of stakeholders and their reluctance to make trade-offs, which obstruct future investment in the SCP. Nature-Based Solutions (NBS) is an umbrella concept that emerged from Europe, which encourages the holistic idea of considering wider options that combine “Blue–Green” practices with traditional engineering to deliver “integrated systems of Blue–Green–Grey infrastructure”. NBS includes interventions making use of natural processes and ecosystem services for functional purposes, and this could help to improve current pilot SCP practices. This manuscript reviews the development of the SCP, focusing on its construction and design aspects, and discusses how approaches using NBS could be included in the SCP to tackle not only urban water challenges but also a wide range of social and environmental challenges, including human health, pollution (via nutrients, metals, sediments, plastics, etc.), flood risk, and biodiversity

Optimizing Low Impact Development Controls for Sustainable Urban Flood Risk Management

Increased urbanization and a changing climate are contributing to an increased urban flood risk. Low Impact Development (LID) is a green infrastructure approach to help mitigate this risk. Analysis of flooding potential and socioeconomic factors of an urban area are essential in determining how to best implement these controls. The objectives of the study was to identify the most prominent areas for LID implementation and develop a framework for identifying LID controls within a multiobjective optimization framework. Coupled risk assessment and socioeconomic analysis was used to determine the potential areas to implement LID controls to achieve continuous benefits. A risk assessment methodology was developed to delineate the greatest flooding risk areas in sewersheds. A socioeconomic analysis framework was then adapted to assess the areas that would be most likely to adopt and successfully maintain LID controls. A simulation-optimization framework was then developed by coupling Stormwater Management Model (SWMM 5) with the Borg Multiobjective Evolutionary Algorithm (MOEA). This methodology analyzed different LID implementation solutions with a cost function to determine the most cost effective LID solutions. The PCSWMM interface was used to create the model for a large urban sewershed in Windsor, Ontario, Canada. The model tested LID measures against eight different scenarios consisting of both historical climate data and future predicted climate change data with the objectives of reducing peak flows in the sewer system, reducing total runoff across the sewershed and minimizing the cost of LID implementation. The results provide stormwater management professionals and decision makers cost-benefit information for different LID implementation scenarios to help assess the feasibility of LID in this area and to make infrastructure investment decisions

Desarrollo de una herramienta de apoyo para la toma de decisiones en la selección de sistemas sostenibles de drenaje urbano: aplicación en la ciudad de Laval (Canadá)

[ES] El uso de Best Management Practices (BMPs), o Sistemas de Drenaje Sostenible (SUDS) en español, ha aumentado significativamente en las últimas décadas como una alternativa eficaz a los sistemas de drenaje tradicionales. Sin embargo, la enorme variedad de tipos de BMPs, la insuficiente experiencia en este campo de algunos gestores de aguas pluviales y la poca normativa y guías técnicas existentes, a menudo hacen que la selección de una BMP para su instalación en un lugar determinado se convierta en un problema complejo de la toma de decisiones. El objetivo principal de este estudio fue desarrollar una herramienta de toma de decisiones para ayudar a los gestores de aguas pluviales en los problemas de selección de BMPs. La metodología propuesta consiste en clasificar 14 BMPs diferentes en función de 4 criterios principales y de las condiciones específicas del lugar de instalación. Se utilizaron herramientas innovadoras para evaluar los indicadores de algunos criterios. El programa de clasificación de BMPs se desarrolló basándose en dos métodos multicriterio de ayuda a la decisión ampliamente conocidos: AHP y ELECTRE III. Además, se estudiaron diferentes escenarios simulados: se consideraron 3 tormentas de diseño distintas y las preferencias en cuanto a objetivos de gestión se establecieron en función de los puntos de vista de 3 actores diferentes. La metodología desarrollada se aplicó en una cuenca residencial urbana en Canadá. Los resultados obtenidos con ambos métodos fueron comparados. A pesar de algunas diferencias evidentes, las mejores y peores posiciones en la clasificación fueron ocupadas en general por las mismas BMPs en ambos rankings. También se observó que las diferentes lluvias consideradas no afectan a los resultados de la clasificación. Además, el método AHP resultó ser más sensible a las variaciones en los pesos de los criterios que ELECTRE III. Por último, se realizaron análisis de sensibilidad para evaluar la solidez de la metodología. Los resultados no parecieron sensibles a algunos de los parámetros y datos de entrada evaluados por lo que la metodología podría considerarse robusta. A pesar de los prometedores y satisfactorios resultados se hicieron algunas recomendaciones para los futuros investigadores al final del estudio.[EN] The use of Best Management Practices (BMPs) has increased significantly in the past decades as an efficient alternative to traditional drainage systems and practices. However, the huge variety of BMP types, the insufficient experience in this field of some stormwater managers and the little existing regulatory texts or guidelines, often make the selection of a BMP installation a complex decision-making problem. The main objective of this study was to develop a decision-making tool to assist stormwater managers in BMPs selection problems. The proposed methodology consisted in ranking 14 different BMPs according to 4 main criteria and specific site conditions. Innovating tools were used to evaluate some criteria indicators. The developed ranking program was based on two multicriteria decision-aid (MCDA) well-known methods: AHP and ELECTRE III. Besides, different simulated scenarios were studied: 3 design storms were considered and management preferences were in accord with 3 different stakeholders¿ points of view. The developed methodology was applied in a demonstration site in Canada. Results issued from both MCDA methods were compared. Despite some evident differences, the best and worst ranking positions were occupied in general by the same BMPs in both rankings. It was also observed that the different considered rainfall inputs didn¿t affect the ranking results. In addition, AHP method was found to be more sensitive to criteria weights variations than ELECTRE III. Finally, sensitivity analyses were made to evaluate the methodology robustness. Results didn¿t seem sensitive to some parameters and input data so methodology could be considered robust. In spite of the promising and satisfactory results, recommendations for future researchers were also established at the end of this study.Maté Marín, A. (2012). Sustainable stormwater management: development of a decision-making tool to help in best management practices selection. Case study in Laval (Canadá). http://hdl.handle.net/10251/27245Archivo delegad

A critical review of MCDA practices in planning of urban green spaces and NBS

ABSTRACT: Green spaces and nature-based solutions (NBS) are increasingly considered by land-use planning policies to respond to the multiple challenges related to sustainable development. The multiple benefits brought by NBS make the use of multicriteria decision analysis (MCDA) essential to optimally balance their use. MCDA offers a catalog of methods allowing to structure problems with multiple objectives and to help adopt the optimal solution. However, NBS planning is a recent discipline and research is still ongoing to make this practice more common. We carried out a critical literature review on MCDA-NBS tools and practices, following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method on the Web of Science database. We selected 124 papers on the subject between 2000 and 2022. We present a state-of-the-art MCDA approach for NBS and green space planning by looking at where these practices are applied, why and how this process is conducted, and who is involved in it. We found that studies are usually conducted in the global North on a single case study with the help of experts involved in the criteria weighting phase and the help of GIS MCDA tools often integrating a direct ranking method or the AHP method

Spatial Methods for Green Infrastructure Planning. Strategies for Stormwater Management and Park Access

M.A.M.A. Thesis. University of Hawaiʻi at Mānoa 201