Forest fires; wildfires; wildland fires - these are all different names for unwanted, nonstructural fires that occur in landscape settings. The destructive power and the need for rapid detection, containment, control and suppression of wildfires has been well recognized since before the birth of Smokey the Bear. More recently, the outward expansion of the urban environment and the commingling of living communities in natural forest settings has given rise to the term urban wildland interface and the realization of the greater economic impact and threat to life caused by some wildfires. But the problem does not stop there. The combination of population increase, climate change - whether a natural cycle or man-made - and any form of deforestation, is likely to have a major impact on watershed conservation and, hence, fresh water availability as well as soil erosion and wildlife habitats. So, the need for protecting undeveloped lands, particularly forests, is greater today than it has ever been in the recent past.
For centuries, people have relied on human detection of forest fires. It should not be a surprise that the 21st century is bringing some technological - and even biological - systems to bear on the problem. This article is an introduction to the concept of automated forest/wildland fire detection and a summary of some of the work being done by scientists and engineers.
In addition to the possibility of more rapid detection, other potential needs, problems and solutions are driving technological developments. These include:
- the need for near real-time data input for wildland fire spread models;
- the need for fire ground mapping to aid in resource allocation and deployment;
- the need for vector modeling to manage evacuations and relocations using emergency communications systems (ECSs);
- the need to project or model possible impact on critical infrastructure components, including remotely located cellular communications facilities used as part of an ECS; and
- the need to automatically activate exterior structural defense systems, such as structural foam applications and urban-wildland interface spray systems.
All of these "needs" give rise to potential technological solutions.
Many efforts to automate forest and wildland fire detection have focused on image-based systems. Some image systems use fixed cameras or sensing units similar to those used in many of today's video-based fire and smoke detection systems. These may use visible or infrared bandwidths for image processing. Geostationary satellites using both visible and infrared imagery have also been investigated and found to have a detection resolution comparable to human detection, but over larger areas.1, 2
Improvements have been proposed that will increase resolution and decrease detection time. In addition to using satellites and fixed towers as sensor platforms for these technologies, the use of unmanned aerial vehicles (UAVs) is also possible.3 Other remote sensor-based systems have been tested using radar, light detection and ranging (LIDAR) and sound detection and ranging (SODAR). Radio-acoustic sounding systems have also been tested as ways for remote measuring of crown and surface temperatures.4
Infrared wavelength sensors have a disadvantage in that smoke, dust and fog all absorb some of the infrared emissions from a fire. The use of detectors sensitive to longer wavelengths has been investigated and shown to be promising.5
The use of fiber optic cables, gas sensors and other opto-electronic sensor networks have also been tested in actual forest settings.6 While promising, these systems might have scale limitations due to power requirements and sensor installation and distribution requirements. Also, long term resiliency and survivability of equipment and systems deployed in remote forest and wildland locations has not yet been demonstrated.
As is often the case, innovation often originates outside of a discipline and, frequently, Mother Nature is the inspiration. Entomology is the study of insects. Scientists at several European Universities and organizations have collaborated to study the Black Jewell Beatle (Melanophila acuminata) and the Australian Pyrophilic Beetle (Merimna atrata). Entomologists have known for some time that both of these beetles need freshly burnt wood to survive. Consequently, both have evolved antennae organs that are very sensitive to certain volatile organic compounds (VOCs) released by burningwood.7 In addition, the Black Jewell Beetle has a pair of very sensitive infrared (IR) arrays, each with approximately 90 IR receptors.8 These VOC and IR sensors guide the migration of these beetles towards forest fires. Researchers have worked to isolate and understand how these insect olfactory and IR sensors work. They have also begun to replicate the sensors using electronic "noses" and "eyes".
In addition to research on wildfire detection, work is being done on how to best communicate and manage the available information. Many communities that regularly experience wildfires have some form of centralized wildfire command center or network. The use of standard Geographical Information Systems (GIS) can permit real-time data sharing among different agencies. Commanders can quickly look at satellite imagery overlaid with road maps, real estate information and fire progress maps. They can switch to or overlay views showing power transmission lines, cell towers and other fixed infrastructure elements. GPS location data permits real time viewing of resource deployments.
These are just some of the ways that technology and biology are being used to manage forest and wildland fire risks through the development and use of detection, signaling and information management systems.
- Weaver, J. Lindsey, D., Bikos, D., Schmidt, C., & Prins, E., "Fire Detection Using GOES Rapid Scan Imagery," Weather and Forecasting, Volume 19, Issue 3, June 2004.
- "Forest Service Early Warning Systems," Science News Daily, http://www.sciencedaily.com, 11 December 2009.
- Kruell, W., Willms, I., Tobera, R. & Wiggerich, B. "Early Forest Fire Detection and Suppression - An Integrated Approach,"Proceedings of the 14th International Conference on Automatic Fire Detection, Duisburg, Germany, 2010.
- Sahin, Y & Ince, T. "Early Forest Fire Detection Using Radio-Acoustic Sounding System," Sensors - Open Access Journal, 03 March 2009.
- Von Wahl, N. & Heinen, S. "Advantages of Millimeter Waves in Fire Detection and Monitoring," Proceedings of the 14th International Conference on Automatic Fire Detection, Duisburg, Germany, 2010.
- Corsi, N. and Gemelli, A. "An Innovative Approach to Forest-Fire Detection and Monitoring: The EU-FIRE Project," Proceedings of the 14th International Conference on Automatic Fire Detection, Duisburg, Germany, 2010.
- Paczkowski, S., Weibecker, B., Schtz, S., Eberheim, A., Kohl, D. & Schieberle, P. "Biomimetric Wood Smoke Assessment on the Basis of Insect Olfactory Systems," Proceedings of the 14th International Conference on Automatic Fire Detection, Duisburg, Germany, 2010.
- Schmitz, H., Bousack, H. Schmitz, S. & Lacher, M. "The Infrared Sensilla in the Beetle Melanophila Acuminata as Model for New Fire Sensors," Proceedings of the 14th International Conference on Automatic Fire Detection, Duisburg, Germany, 2010.