UCLA

The dissertation presents three papers examining exposure to extreme heat and wildfire in the Western United States. In the first chapter, I develop a framework for analyzing transit passenger exposure to extreme heat in Maricopa County and then implement an optimization algorithm for minimizing wait times through the reallocation of buses across the transit network. In simulating the reconfiguration of buses, I find the potential for small adjustments to produce large reductions in wait time for vulnerable populations. This work also formulates a way to measure passenger vulnerability with an activity-based model that accounts for the distinct demographics of transit riders.

In the second chapter, I study the prevalence of ground level wildfire smoke, specifically particulate matter 2.5�m in diameter, in California during the 2020 wildfire season - the most severe wildfire season ever recorded by the state. For the first time, I study how frequently extreme smoke levels at surface level coincide with extreme heat in space and time. These interactions can influence adaptive behaviors and studies show evidence of increased hospitalizations when these hazards co-occur. I find that a majority of Californians experienced at least one day of concurrent heat and smoke in 2020 and that these events were concentrated in more rural areas of the State. This case study motivates the integration of multi-hazard frameworks in both public and private sector risk planning.

In the final chapter, I examine wildfire risk factors for residential property in California. I leverage a dataset collected by CAL FIRE enumerators who record the features of a home and categorize the level of damage after every named incident. I enhance this dataset using remotely sensed detections of wildfire to impute the date when a home burned from which I then estimate time-varying weather risk factors like humidity, temperature and wind as well as fire intensity. I then use these features to train a predictive model to be used by homeowners or insurance carriers to better estimate the vulnerability of their property.