Conference: 

Pagan-Cajigas, Z. P., Guikema, S., “Enhancing Community Resilience: A Simulation-Based Framework for Post-Hazard Access to Essential Services at the Building Level” 2025 European Safety and Reliability Conference & Society of Risk Analysis - Europe, Stavanger, Norway

Pagan-Cajigas, Z. P., Guikema, S., “Enhancing Community Resilience: Assessing Post-Disaster Access to Essential Services through a Community-Driven Evaluation”, 2024 Society of Risk Analysis Annual Meeting, Austin, Texas

The AccES (Predicting Access to Essential Services) model is a forward-looking framework that evaluates access to essential services at a building level, before and after hazard events. A key component of this model is its integration of local stakeholder knowledge through interviews and surveys.

By leveraging publicly available data, AccES enables the assessment of both past and future disruptions, providing a scalable and data-driven approach to resilience planning. The model operates through the following key components:

1. Developing spatially-explicit, detailed engineering models of an interdependent essential services network (e.g., power, water, communication, hospitals, grocery stores) using publicly available data.

2. Simulating hazard impacts to assess the operational status of essential services at the building level.

3.  Evaluating accessibility changes at the building-level due to service disruptions, and quantifying the impact of hazards on community access to critical services.

The AccES model offers a data-driven, people-centered decision-support framework, enabling decision-makers to understand service accessibility challenges and develop strategies for equitable disaster response and recovery.

This research investigates the projected risks of future climate trends on tropical cyclone-induced power outages in the Gulf and Atlantic coasts of the United States, focusing on the disproportionate impacts on vulnerable populations and potential economic burdens. Our methodology integrates three well-documented models to estimate changes in power outage rates and socio-demographic inequities due to tropical cyclone projections. Synthetic tropical cyclones, generated using data from seven global climate models (GCMs), were used to compare power outage risks at the census tract level along two periods: hindcast (1995-2014) and late-century (2071-2100) using the SSP5-8.5 scenario. The late-century results from each model were scaled to align with a global warming scenario of 3◦C. The uncertainty of these projections was evaluated considering the agreement among the GCMs’ outage projections. Results highlight a significant increase in power outage risks and high agreement in northern Florida, Georgia, and the mid- and North Atlantic coast. Environmental Justice analyses indicate higher outage risks for Hispanic, elderly, and low-income populations. The findings highlight the need for adaptive strategies and equitable resource allocation to mitigate growing risks due to future climate projections.

Submitted Paper: Guikema, S., Pagan-Cajigas, Z.P., Fant, C., Boehlert, B., Maier, C., Emanuel, K., Hartin, C., Sarofim, M., Climate Change Impacts on Tropical Cyclone-Induced Power Outage Risk: Inequities in Outage Risk Economic Burdens, Submitted to Proceedings of the National Academy of Sciences in February 2025.

Conference: 

Pagan-Cajigas, Z. P., Guikema, S., "Estimating Tropical Cyclone-induced Power Outages in Future Climate Scenarios' Impact on Socio-economically Vulnerable Populations and Racial Minorities", 2023 Society of Risk Analysis Annual Meeting, Washington, District of Columbia

Pagan-Cajigas, Z. P., Guikema, S., Fant, C., Boehlert, B.,  "Estimating Tropical Cyclone induced Power Outages in Future Climate Scenarios.", 2023 European Safety and Reliability Conference, Southampton, United Kingdom 

Developed an algorithm that generates a synthetic water distribution system using only publicly available data. The method is generalizable and can be scaled to different spatial levels. Our approach provides hydraulic information at the building level to support infrastructure resilience assessments. The hydraulic model uses the Water Network Tool for Resilience (WNTR) Python package, an open-source package used to simulate and analyze the resilience of water distribution networks to a wide range of hazardous events. 

The model was validated by comparing the network topology and hydraulic properties with data from the real water system of Ann Arbor, Michigan. Our synthetic model results indicate 95% of the simulated building-level pressures were within ±25 PSI of the hydraulic model data from the existing system. To demonstrate an application of our model, we simulated water outages at the building level using hazard loading and fragility functions corresponding to an earthquake scenario.

Published Paper: Pagan-Cajigas, Z. P., Guikema, S., Otaduy-Ramirez, R., Woolley, V., Smith, K., Hu, T., Chen, T. Water outage predictions for natural hazards using synthetic water distribution systems. Risk Analysis, Volume 2, 2025, DOI: 10.1111/risa.70004

Conference: Pagan-Cajigas, Z. P., Guikema, S., "Water outage predictions for natural hazards using synthetic water distribution systems.", 2022 Society of Risk Analysis Annual Meeting, Tampa, Florida 

This research establishes ten evaluation criteria for conceptual frameworks designed to identify, prioritize, and protect critical services and their supporting infrastructure (CSIs). The proposed criteria focus on two main objectives: 1) ensuring that the CSIs identified by the frameworks reflect community-specific needs, values, and preferences, and 2) evaluating if they provide the necessary information required for risk, resilience, and equity assessments. These insights are crucial, as they are often used as inputs for resource allocation decisions. To demonstrate the application of these criteria, the study evaluated three representative frameworks: Critical Infrastructure (CI), Vital Societal Functions (VSF), and Equitable Access to Essential Services (EAE), highlighting their strengths and limitations. The findings reveal that none of the evaluated frameworks fully meet the proposed criteria; for instance, they inadequately address localized interdependencies, uncertainties, and equity considerations. The study underscores the importance of integrating best practices from existing frameworks while addressing their conceptual gaps. It provides actionable guidance for the future development of frameworks to better align with community-specific priorities and improve resource allocation strategies. 

Submitted Paper: Pagan-Cajigas, Z. P., Guikema, S., Flage, R. Are Existing Frameworks Effective in Identifying and Prioritizing Critical Services and Infrastructures at a Local Level? Establishing Standardized Evaluation Criteria. Submitted to Civil Engineering and Environmental Systems in February 2025.

Conference: Pagan-Cajigas, Z. P. , Guikema, S., Flage, R., “A Framework Comparison for Community Level Risk Assessments”, Risk Analysis Specialty Group (FRASG) Student Merit Award winner, 2021 Society of Risk Analysis Annual Meeting, Virtual 

Conducted a community-level assessment in the Caribbean to understand the services perceived as essential for different socio-demographic groups. Additionally, we assessed each service's importance ratings and the community's restoration preferences following a hazardous event. 

The results were analyzed using statistical analysis and logistic regression analysis. The logistic regression analysis was performed to evaluate whether there is a relationship between the explanatory variables (e.g., age, gender, income) and the response variables (e.g., perceived level of impact, restoration preferences).

The findings of this work were integrated into subsequent work: " Are Existing Frameworks Effective in Identifying and Prioritizing Critical Services and Infrastructures at a Local Level? Establishing Standardized Evaluation Criteria" and "Enhancing Community Resilience: A Simulation-Based Framework for Post-Hazard Access to Essential Services at the Building Level”.

Conference: Pagan-Cajigas, Z. P. , Guikema, S., “Equitable Access to Essential Services: A community-level assessment of essential services in the Caribbean.”, 2022 IISE Annual Conference & Expo, Seattle, Washington