Suppression resources and their influence on containment of forest fires in Victoria

Background. Wildfire suppression is becoming more costly and dangerous as the scale and severity of impacts from fires increase under climate change. Aims. We aim to identify the key environmental and management variables influencing containment probability for forest fires in Victoria and determine how these change over time. Methods. We developed Random Forest models to identify variables driving fire containment within the first 24 h of response. We used a database of ~12 000 incident records collected across Victoria, Australia. Key results. Response time, fire size at first attack, number of ground resources deployed (e.g. fire fighters), ignition cause, and environmental factors that influence fire spread (e.g. elevation, humidity, wind, and fuel hazard) were key drivers of suppression success within the first 24 h. However, certainty about the factors influencing suppression reduced as the containment period increased. Conclusions. Suppression success hinges on a balance between the environmental factors that drive fire spread and the rapid deployment of sufficient resources to limit fire perimeter growth. Implications. Decreasing the period between an ignition and the time of arrival at the fire will allow first responders to begin suppression before the fire size has exceeded their capability to construct a control line.