MODERNIZING TORNADO SIREN SYSTEMS IN GLENPOOL, OK: A GIS-BASED, EQUITY-DRIVEN, AND COST-EFFECTIVE FRAMEWORK

Abstract

Outdoor warning sirens remain a critical component of tornado risk communication, particularly for individuals who are outdoors or in public spaces during rapidly evolving severe weather events. Despite their importance, many siren networks in the United States have evolved incrementally, relying on simplified acoustic assumptions and site-by-site decisions rather than systematic evaluation of coverage efficiency, equity, or cost-effectiveness. This study presents a reproducible GIS-based decision-support framework that integrates physics-based acoustic modeling, equity-weighted demand surfaces, and mixed-integer linear optimization to guide outdoor warning siren planning under realistic fiscal and spatial constraints.The framework modernizes the legacy SPreAD-GIS acoustic model for use within ArcGIS Pro and embeds modeled outdoor audibility into a budget-constrained optimization problem that maximizes unique coverage across population, social vulnerability, and outdoor activity areas. The methodology is demonstrated through a case study of Glenpool, Oklahoma, evaluating both existing and expanded siren inventories across multiple policy-weighting and budget scenarios. Results indicate that baseline siren networks exhibit substantial avoidable coverage loss driven primarily by spatial configuration rather than inventory size. Across scenarios, optimized relocation of existing sirens consistently outperformed incremental expansion strategies at equivalent or lower investment levels. In the Glenpool case study, optimized relocation achieved coverage comparable to—and in some scenarios exceeding—a realized network expansion at substantially lower capital cost. Equity-forward optimization did not reduce overall population coverage, instead redirecting coverage from redundant overlap toward higher-need areas. These findings demonstrate that optimization-guided reconfiguration can significantly improve the effectiveness, equity, and fiscal efficiency of outdoor warning systems. The proposed framework provides emergency management agencies with a transparent and defensible tool to evaluate trade-offs, prioritize investments, and strengthen the analytical foundation of hazard mitigation planning and funding applications.