Many physically-based models of surface and groundwater hydrology are constructed without the possibility of multiple stable states. For such a conceptualisation, at the cessation of a transient hydrological disturbance of any magnitude, the model will return to the original stable state and therefore will have an infinite resilience. Ecosystem resilience science propose a very different dynamic where, if the system has a positive feedback, disturbances may shift the system over a threshold where, upon cessation of the disturbance, the system will move to a different steady state. This dissertation brings together concepts from hydrology and ecosystem resilience science to highlight this often implicit assumption within hydrology. It tests the assumption that dry land water-limited catchments always have only one steady state (henceforth referred to as 'attractor'). Following a discussion of this implicit assumption within hydrology, approaches for rigorous testing that could result in its falsification are considered and that of numerical modelling is adopted. The aims of the research were to test this assumption by proposing a biophysically plausible hydrological model; utilise it to investigate the catchment attributes likely to result in multiple attractors; and to assess the model's validity by way of implementation and calibration. (For complete abstract open document.)

Evaluating the resilience of transportation infrastructures, including bridges, roads, and tunnels, is a critical aspect of ensuring the ongoing functionality and reliability of urban or regional areas in the face of various disruptive events. Such infrastructures are susceptible to a range of disruptions which can have significant impacts on their ability to function effectively. Resilience refers to the capacity of an infrastructure or a system to withstand and recover from these disruptions. This research presents a framework to evaluate the resilience surface for assessing the resilience of various transportation infrastructure components. This comprehensive approach involves several steps. First, the framework identifies unique damage configurations by performing a fragility analysis. This analysis allows for a better understanding of how susceptible the infrastructure is to different hazards. Next, the framework focuses on the restoration of the affected infrastructure by developing recovery curves for each identified damage configuration. This is done by taking into account relevant restoration data and considering the specific characteristics of each configuration. Additionally, the framework acknowledges the inherent uncertainty that exists within various aspects of infrastructure resilience assessment. These uncertainties include hazard intensity, modeling uncertainty, and the restoration process itself. By incorporating these uncertainties into the framework, a more accurate and reliable assessment can be achieved. The utility of this framework is demonstrated through its application to a real-world case study involving a highway bridge located in Canada. The goal of this research is to offer decision-makers a valuable tool for evaluating the resilience of transportation infrastructure. This can contribute to more robust and reliable transportation infrastructures, capable of withstanding and recovering from a wide range of disruptive events. / Thesis / Master of Applied Science (MASc) / Resilience quantification of infrastructures is the assessment and measurement of their ability to withstand and recover from disruptive events. However, there is a significant research gap in this field, with limited studies and standardized methodologies available. This research presented a framework to quantify the hazard resiliency of infrastructures through development of resilience surface. The framework and the procedure were then numerically tested on a real bridge in Canada as a case study.

The use of fully grouted reinforced masonry shear walls (RMSWs) has been growing in several areas around the world owing to their relative ease of construction and their in-plane ductile behavior. However, RMSWs possess low out-of-plane ductility which amplifies the vulnerability of such components under blast loading. Furthermore, the long time and high costs of recovery following devastating (deliberate or accidental) explosions have created a need for resilience-based design for risk mitigation, especially considering the different sources of associated uncertainty. As such, this study aims to lay out the foundations of a probabilistic resilience–based blast analysis and design framework. The framework should have the capability of quantifying the overall building post-blast functionality in order to estimate its recovery cost and time, and thus the building resilience following such a demand. The proposed framework will be specifically applied for RMSW buildings incurring blast loads through a profound investigation for the behavior of rectangular RMSWs as being a primary structural element in reinforced masonry buildings. The investigation will subsume an experimental and analytical evaluation for the performance of load-bearing RMSWs with different in-plane ductility levels subjected to out-of-plane quasi-static loading. This will be followed by a numerical investigation of RMSWs to conclude the blast probabilistic performance of RMSWs that can be applied within the proposed probabilistic resilience-based blast framework. The work in this dissertation presents a key step towards adopting resilience based analysis and design in future editions of blast-resistant construction standards and provides the decisionmakers with a complete insight into post-blast building functionality and its recovery. / Thesis / Doctor of Philosophy (PhD)