Forest fires have a significant impact on the global environment and are increasingly occurring with more frequency than ever before. They cause massive losses of life and property, as well as threatening the natural ecological systems. The use of remote sensing technology to monitor and detect fires is an effective means of reducing their impact on the environment.
“In the case of large-area fires, satellite data allow you to plan firefighting and evacuation actions. In analyses related to fires, imaging by various sensors can be used, but high time resolution is crucial, allowing imaging to be performed during the fire or at least a few days after it. More and more recent Earth Observing system satellites have the advantage to allow daily image acquisition,” says Jaurez Dorfling, Managing Director at Geo Data Design. GEO Data Design are providers of geospatial solutions using very High Resolution Satellite Imagery and Location-Intelligence.
“Furthermore, remote sensing technology is becoming more prevalent in Forest Fires Management. The increasing availability of satellite imagery together with the development of the geographic information technology allows monitoring of fire risk and estimate post-fire damage spatially,” observed Jaurez.
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“During long periods of drought and heat, forest ecosystems are particularly at risk of fire as the dried, fallen trees and shrubs, turn into fuel that are easily ignited. An accurate knowledge of the fuel condition is critical in monitoring and preventing fires,” he adds.
Margherita Bruscolini, Globhe‘s Head of Drones, is affirmative that, remote sensing and drones play a critical role in forest fire management by providing valuable information about the fire’s behavior, extent, and severity. These technologies help in planning and executing fire management strategies by detecting and monitoring forest fires. GLOBHE – Offers accurate and actionable drone data from anywhere in the world, accessed through one single platform.
Using Satellites in Forest Fire Monitoring
Many fire managers are already familiar with the capabilities of satellites to monitor the environment, and their value for forest fire monitoring is increasing. This technology can provide useful information on the location, extent and direction of fires as well as the evolution of their activity.
“Remote sensing can provide information about the location, size, and intensity of fires, as well as the types of vegetation and terrain affected. Satellite-based remote sensing allows for the detection and monitoring of fires over large areas. At the same time, drones and ground-based sensors can provide high-resolution images, maps, and real-time footage about the fire’s behavior,” enhances Margherita.
Several satellite-sensor platforms are available, each offering its own set of specific characteristics for detecting and imaging fires. The wavelength bands used, the spatial resolution of the sensor and its coverage area are all critical factors for identifying the right satellite for fire detection.
One important feature of optical remote sensing imagery is the presence of smoke plumes, which are a visual indicator of active fires. Optical sensors onboard satellites can detect these plumes and provide information on the locations of fires in high resolution images.
“Drones are increasingly being used in forest fire management to provide real-time data and imagery to firefighters and other responders. Drones equipped with infrared cameras can detect heat and smoke, providing information on the fire’s location and spread. High-resolution cameras on drones can also provide detailed images of the fire’s behavior, which can be used to plan firefighting strategies and assess the fire’s impact on the ecosystem,” highlights Margherita.
These satellites can also identify hot spots, which are areas of intense heat radiating from fires. These hot spots can be detected by infrared (IR) sensors onboard satellites, thereby providing additional information on the general location, shape and direction of fires, and their duration.
“In addition to providing valuable data for firefighting and management, remote sensing and drones can also help prevent forest fires by providing early warning of potential ignition sources, such as hotspots or lightning strikes. This information can be used to quickly respond to potential fires, reducing the risk of large-scale forest fires,” affirms Margherita.
Some of these sensors can also detect fires that are smoldering, but this can be difficult because smoldering fires have a lower emissivity than active fires, which reduce the intensity of the thermal signal received by the sensor.
Managing and Monitoring Forest Fires with Remote Sensing
The ability to rapidly detect fires is vital for assessing the effectiveness of firefighting operations and the progress of wildfire suppression efforts. This requires that fire teams have access to up-to-date information about fire ecology, land mapping and other remote sensing technologies, and staff with knowledge of these topics.
Fire teams can also benefit from having a dedicated space within their organization to develop and implement their own remote sensing tools. This can include office space, adequate hardware and software and trained staff with access to up-to-date literature.
There are many different tools that can be used to monitor and assess fires with remote sensing, including radar, laser scanning, LiDAR and thermal imagery. Depending on the needs of the fire management team, these tools can be combined with data derived from other remote sensing applications such as aerial photos or GPS.
“Several pre-fire conditions can be monitored using remote sensing. The first one is related to the fuel type, which can be mapped, like classical vegetation mapping, from high spatial resolution optical or radar images. In such analyses, the spectral range of red and infrared channels of the Visible and Infra-Red portion of the electromagnetic spectrum is of particular importance. For evaluation of fire-affected areas and burn severity the visible and shortwave infrared (SWIR) regions of the optical sensor are used. Satellite images allow quick estimation of damage and property loss as well as observation the revival of vegetation far ahead,” expounds Jaurez.
“Within the other remote sensing techniques, space-based SAR (radar – working with compressed waves of length 0.1–1 m) has been traditionally used for fuel type mapping, and Light Detection and Ranging (LiDAR) has started to be used for fire prevention and control in larger scale mapping,” adds Jaurez.
“To gain the most information from satellite imagery the Remote Sensing professionals calculate the various indices or indicators from the spectral response value of pixels in two different bands. The most important indices for the analysing forest fire’s hazard are NDVI- Normalised Difference Vegetation Index, NDWI – Normalised difference Water Index, NDDI – Normalized Difference Drought Index and the NBRI – Normalised Burned Ratio. NDVI is the infrared and red bands ratio which shows changes in the state of vegetation. This measure has values varying from -1 to 1. The usual healthy, green vegetation ranges from 0.2 to 0.8. NBRI – Normalised Burned Ratio Index that are used for estimating the severity of the fire,” he describes.
On the other hand, Margherita is optimistic that, utilizing the remote sensing techniques and platforms to expand the preventative work and manage forest fires is extremely valuable for any organization looking to limit the damage of wildfires.
Conclusion
The ability to rapidly detect and map a fire is crucial for ensuring the safety of firefighters and the public. As outlined by the experts, remote sensing techniques allow fire teams to make informed decisions about where to start and how to respond. This helps to ensure that all firefighting resources are fully utilized.
Moreover, early detection of a fire is essential. Current firefighting techniques depend on manual observation, aerial survey or fixed optical cameras. However, with the availability of advanced remote sensing techniques and equipment and high-resolution satellite imagery, forest fire management can now take a more integrated approach to fighting and monitoring wildfires.
