Opening-up of Forests for Fire Extinguishing Purposes

Information on the existence of forest roads as well as their quality is important not only for planning forest management activities, but also for fire management, which includes fire risk assessment and fire suppression. In the case of fire, the level of forest opening-up has a significant influence on the attendance time of fire brigades. Not sufficiently developed road network is often reflected on the elongation of fire-fighting attack and exactingness of shuttle water relay. Therefore, the level of forest opening-up is an important indicator and factor affecting the promptness of fire-fighting activities and further fire spreading, because forest roads also represent a natural barrier against fire. A simple approach to the assessment of the level of forest opening-up has been introduced from the aspect of terrain accessibility for the available mobile fire apparatus with the use of GIS and GNSS technologies. First, the forest road network was mapped using the GNSS technology, and then the information on the quality of particular roads was collected. These data were processed in the ArcGIS 9.3 environment and as a result the geodatabase was created. It was later used to process the opening-up analysis in IDRISI Taiga environment. The opening-up analysis was performed for the Hrabusice forest management district, located in the karst area of the Slovensky raj National Park and the available mobile fire apparatus – pumping appliance CAS 32 on Tatra 148 chassis and forest special UNIMOG on Mercedes chassis. The objective of the opening-up analysis was to identify the zone where the terrain is accessible for mobile fire apparatus and where fire hose piping is admissible. It was based on computation of the maximum range of fire hose piping (maximum sidelong distance), road spacing and the index of forest opening-up. The results of this analysis are valuable as a support for decision making for foresters dealing with forest protection, road planning and construction, for fire brigades in planning fire attacks, as well as for risk managers and crisis managers