New method of forecasting forest fire risk in Poland

Abstract

The possibility of reducing losses caused by forest fires, apart from preventative activities, should be sought primarily in limitation of the area burnt as a result of fires. This objective may be achieved through optimisation of extinguishing activities. The basic requirement of such activities is accurate forecasting of forest fire risk depending on meteorological and physical conditions in forests. The purpose of the research was to prepare a new method of forecasting forest fire risk, which would enable a more precise method of evaluation of the risk of an outbreak of fire in relation to existing and forecast meteorological conditions in forests. Establishing provisional assumptions of the new method accepted: • possibility of determining actual fire risk, • possibility of forecasting forest fire risk for the afternoon hours in the morning hours of the given day and the following day, • possibility of forecasting the moisture content of pine litter (Pinus silvestris L.), • preparation of a method enabling limitation of fire prevention system operating costs. To enable drawing up a fire risk forecast (in the morning for the hours of the afternoon and the following day) formulae were drawn up equally enabling calculation of predicted moisture content of pine litter on the basis of its actual current values and forecast meteorological values. The basis for assessment of the proposed method were data relating to the frequency of occurrence of particular degrees of risk, average number of fires in forecast zone depending on the degree of risk and also the average area of fire at the given degree. The drawn up method is based on moisture measurements of flammable material, which has a significant relationship to its precision. Selection of test material – pine litter is adjusted to the specific conditions occurring in the majority of pine stands (Pinus silvestris L.) in Poland. As a result of the work it was possible to create a prognosis method enabling precise establishment of the fire risk in forests according to the accepted assumptions. The results obtained during testing of this method indicate a high accuracy in forecasting fire risk and a satisfactory precision of formulae for calculating moisture content of litter. On this basis it may be stated that the drawn up method enables a decidedly better means to define the actual fire risk, simultaneously providing its forecast for later hours and it is currently introduced for application in fire protection of Polish forests. Such a solution may bring about a significant limitation of fire protection operating costs in forests and facilitate organisation of the work of the services responsible for it.