Synopsis

This report assesses the role of Ventura County’s SOAR (Save Open-space and Agricultural Resources) properties in guiding and mitigating wildfire risk using species distribution modeling (Maxent) and connectivity analysis (Circuitscape). Maxent modeling predicts the probability of fire occurrence using environmental variables such as climate, elevation, slope, and land cover. These variables are used to build a fire habitat suitability map, where higher suitability reflects a greater likelihood of fire based on past patterns and future conditions. This habitat suitability surface is then transformed into a resistance layer—a landscape that assigns “costs” to movement, where high fire suitability corresponds to low resistance (fire moves easily), and low suitability corresponds to high resistance (fire movement is inhibited). This resistance layer is then used in Circuitscape to model landscape connectivity for fire by simulating electrical current flow across the resistance surface. Areas with higher resistance (e.g., irrigated farmland, water bodies) function like resistors, while fire-prone terrain (e.g., mountains, chaparral) facilitates flow.

By modeling both future fire suitability and present-day least-cost fire pathways, the study explores how land use, development restrictions, and ecological dynamics shape fire behavior. While fire is a natural and essential part of California’s ecosystems, it becomes dangerous when it spreads unchecked into urban areas. The modeling shows that SOAR lands—particularly agricultural and open space areas—help corral fire, providing a space for it to burn away from cities and sensitive infrastructure. Circuitscape results show that fire pathways consistently avoid agricultural parcels wherever possible, instead traveling through mountainous terrain and undeveloped land. In this way, SOAR properties function not only as fire buffers, but also as strategic zones where ecologically beneficial fire can occur with reduced threat to human life and property. These findings underscore the critical role SOAR lands play in maintaining both fire resilience and ecological function. By preventing sprawl and protecting strategic open spaces, SOAR allows for safer fire movement while preserving essential natural processes.

Mapping Fire Pathways

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