Inclusive Urban Flood Resilience in a Developing Economy: Case of Georgetown, Guyana

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Description
Inequities and exclusions, compounded by the increasing intensity of extreme weather events, pose significant challenges to urban planning for low-elevation coastal zones (LECZ). Inclusive development (ID) and urban flood resilience (UFR) have emerged as widely endorsed solutions by scholars. Granting

Inequities and exclusions, compounded by the increasing intensity of extreme weather events, pose significant challenges to urban planning for low-elevation coastal zones (LECZ). Inclusive development (ID) and urban flood resilience (UFR) have emerged as widely endorsed solutions by scholars. Granting that they gain substantial support and enthusiasm, they have the potential to transform vulnerable urban areas. While their noble intentions are commendable, the intricacies of ID cannot be overlooked, as UFR often inherits and perpetuates the inequalities ingrained in conventional development paradigms. Given the critical importance of ID and UFR in contemporary urban planning, my dissertation research devolved into their fusion by answering my main research question, what constitutes inclusive urban flood resilience? This investigation was carried out through a series of four secondary research questions distributed over three academic papers, each contributing a unique perspective and insights to this burgeoning field. Through a systematic literature review and employing bibliometric and thematic analyses, Chapter 2 offers a comprehensive understanding of inclusive development and a refined definition of the concept. Subsequently, taking Georgetown, the capital city of Guyana, as a case study, Chapter 3 estimates its UFR and employs dimensionality reduction by way of principal component analysis to present these findings in a transparent manner. Chapter 4 builds on the findings of the previous chapters, by first presenting a novel approach to evaluate inclusive development within the framework of the results of Chapter 2, and secondly, together with a systematic meta-analysis of flood resilience measurements, it offers an examination of the ID-UFR nexus. The findings suggest that the concept of inclusive development is nuanced by context-specific definitions, that flood resilience in Georgetown varies among its sub-districts, and that city dimensions (natural, built, social, economic, and institutional), as assessed by pooling global studies, do not share synergistic relationships, being a measure of inclusive development. These findings are critical to urban planning in Georgetown and similar contexts globally as they provide data-driven guidance for understanding these concepts and applying them toward developing inclusive and flood-resilient cities and communities.
Date Created
2023
Agent

Complex Hydroclimate System Modeling: Causation, Tipping, and Extremes

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Description
Nonlinear responses in the dynamics of climate system could be triggered by small change of forcing. Interactions between different components of Earth’s climate system are believed to cause abrupt and catastrophic transitions, of which anthropogenic forcing is a major and

Nonlinear responses in the dynamics of climate system could be triggered by small change of forcing. Interactions between different components of Earth’s climate system are believed to cause abrupt and catastrophic transitions, of which anthropogenic forcing is a major and the most irreversible driver. Meantime, in the face of global climate change, extreme climatic events, such as extreme precipitations, heatwaves, droughts, etc., are projected to be more frequent, more intense, and longer in duration. These nonlinear responses in climate dynamics from tipping points to extreme events pose serious threats to human society on a large scale. Understanding the physical mechanisms behind them has potential to reduce related risks through different ways. The overarching objective of this dissertation is to quantify complex interactions, detect tipping points, and explore propagations of extreme events in the hydroclimate system from a new structure-based perspective, by integrating climate dynamics, causal inference, network theory, spectral analysis, and machine learning. More specifically, a network-based framework is developed to find responses of hydroclimate system to potential critical transitions in climate. Results show that system-based early warning signals towards tipping points can be located successfully, demonstrated by enhanced connections in the network topology. To further evaluate the long-term nonlinear interactions among the U.S. climate regions, causality inference is introduced and directed complex networks are constructed from climatology records over one century. Causality networks reveal that the Ohio valley region acts as a regional gateway and mediator to the moisture transport and thermal transfer in the U.S. Furthermore, it is found that cross-regional causality variability manifests intrinsic frequency ranging from interannual to interdecadal scales, and those frequencies are associated with the physics of climate oscillations. Besides the long-term climatology, this dissertation also aims to explore extreme events from the system-dynamic perspective, especially the contributions of human-induced activities to propagation of extreme heatwaves in the U.S. cities. Results suggest that there are long-range teleconnections among the U.S. cities and supernodes in heatwave spreading. Findings also confirm that anthropogenic activities contribute to extreme heatwaves by the fact that causality during heatwaves is positively associated with population in megacities.
Date Created
2023
Agent