A Model of Exurban Land-Use Change and Wildfire Mitigation

As exurban development spreads throughout fire-prone areas of the western United States, the threat of wildfire to life and property grows. To address this threat, wildfire mitigation, such as mechanical thinning, often takes place in areas close to exurban development. This study demonstrates the utility of spatially explicit dynamic models to understand better where the wildland–urban interface is, how it might change in the future, and how this might affect which land would be prioritized for mechanical thinning. Specifically, a model (WHAMED) is presented that forecasts the prioritized locations for future mechanical thinning as a function of projected exurban development in the montane zone of Boulder County, CO. To predict exurban development, WHAMED uses a cellular automata model with rules derived from statistical models of historical exurban development. The study tests two general sets of criteria for prioritizing mechanical thinning, that of the Community Protection Zone and the Healthy Forests Restoration Act of 2003. The study shows that under any forecast of exurban development, and under either set of criteria, prioritized land for mechanical thinning is set to expand primarily on US Forest Service land. Methodologically, the study illustrates the importance of making variability transparent and of providing multiple methods of model validation.