Fire Severity, Changing Scales, and How Things Hang Together

The paper describes attributes of space, time, and process in terms of their relations to wildland fire. It then presents a generic framework, based on eight interrelated scale classes for space, time, and process. The effects of changing scales are discussed in a wildland fire context. A five-layered (society, management, systems, fire, and weather), three-dimensional structure for wildland fire is presented. The paper also discusses inefficiencies and inadequacies inherent in systems with inconsistent scales. It then focuses on the effects of scale differences between fire behavior and fire danger and on an acceptable scale range suggested by the natural evolution of these two systems. The paper then defines fire severity and proposes two types of severity models - situation and extended. Finally, it discusses fundamental differences between situational and extended severity and appropriate space, time, and process attributes for both types of severity models.