Updated May 1999
Introduction | Aquaculture | Forest management | Rangeland assessment | Groundwater exploration | Forest fire management | Forest decline assessment | Crop information systems | Inventory and monitoring of shrimp farms
GIS may be useful in immediately finding the most direct access to endangered areas and in locating water sources
For several years the number of fires in European forests has increased. In the case of Polish forests, a new category of forest fire risk has appeared in some regions. Forest fires are a result of the simultaneous existence of at least three unfavourable phenomena: long- term drought, the effect of air pollution (decline and decay of trees, the formation of loose canopy and lush growth of grasses - all resulting in large amounts of inflammable material) and high tourist presence in forests. Because of this situation, the Polish Forest Service has started to apply new techniques and technologies for forest protection: satellite data and Geographic Information Systems (GIS).
High resolution satellite data such as Landsat Thematic Mapper, SPOT and ERS-SAR combined with low resolution satellite images such as NOAA-AVHRR offer new possibilities to monitor forest fires. They have a number of advantages over conventional means of observation: Using satellite images, it is possible to view vast expanses of land (thousands to tens of thousands of km2 on one image). This can be performed regularly for the same area and recorded in different wavelengths, thus providing information on the state of forest resources. Satellite data can be acquired without encountering administrative restrictions
The operational use of satellite data and GIS for forest fire management has four aspects:
During the dry season, the number of forest fires increases rapidly; many can be observed even on low resolution NOAA-AVHRR images
After locating the fire on the digital forest, the parameters and description of endangered forest stands are displayed, which facilitates fire fighting interventions
The usefulness of satellite data was verified on 26 August 1992 when the largest forest fire ever experienced in Poland (9,000 ha) occurred in the Upper Silesia region and was observed on satellite images. The way the fire spread was exceptional for local conditions, as was evident from the very rapid increase of the burnt area:
|26 August||6 p.m.||600 ha|
|26 August||10 p.m.||2 200 ha|
|27 August||1 a.m.||3 500 ha|
|27 August||9 a.m.||5 500 ha|
|27 August||7 p.m.||5 700 ha|
|28 August||6 p.m.||6 000 ha|
|30 August||6 p.m.||8 500 ha|
The radar data from ERS-SAR and optical SPOT XS (multispectral) and P (panchromatic) images enabled the determination of the burnt area with the same accuracy. However, small clumps of trees which survived could be better distinguished on SPOT image, thanks to high near-infrared reflectance. The use of GIS - not only satellite images but also forest maps and forest inventory data - permitted the determination of the structure of destroyed stands according to age classes, species composition, site quality, canopy closure and stand density. The total loss of timber caused by the fire was about 1.4 million m3 and the financial loss was about US$250 million.
The use of multitemporal satellite images also facilitates the monitoring of recultivation and reforestation efforts as well as the regeneration of the natural forest.
Burnt area seen on SPOT (black) and ERS-SAR (light green) images. Multitemporal images (in this case ERS-SAR) allow monitoring of recultivation
|Costs (US$/km2)||Time (months)|
|Acquisition of satellite data||1.2||1.00|
The use of satellite imagery and of other forest information stored in the GIS databases enables fast and reliable monitoring and assessment of damage to the forest and preparation of up-to-date forest maps, which is a crucial element after forest fires. Geographic Information Systems including satellite data also permit the evaluation and modelling of the forest fire hazard.
The operational use of Geographic Information Systems in forestry is possible after digitizing the forest stand maps related to forest inventory data. The assessment of the forest fire hazard with the use of satellite data is possible when using integrated ground truth and meteorological data.
The study was conducted at the OPOLIS-Remote Sensing and Spatial Information Centre of the Institute of Geodesy and Cartography in Warsaw (Poland) in cooperation with the Laboratory of Remote Sensing and Forest Management, University of Ghent (Belgium) and the Forest Fire Control Section of the Forest Research Institute in Warsaw (Poland).
Adapted from FAO Remote Sensing for Decision-makers Series, No. 12, "Satellite imagery and Geographic Information Systems in forest fire management". For a full list of issues available in the Series, see FAO Publications on Remote Sensing
The designations employed and the presentation of material in this brochure do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authority, or concerning the delimitation of its frontiers or boundaries.
Remote sensing Introduction | Aquaculture | Forest management | Rangeland assessment | Groundwater exploration | Forest fire management | Forest decline assessment | Crop information systems | Inventory and monitoring of shrimp farms