PRACTICAL ESTIMATION OF THE VARIABILITY OF FUEL MOISTURE IN DIFFERENT FOREST ECOSYSTEMS

Abstract

A fire behavior simulation system demands the knowledge of many factors, such as fuel moisture content, because it affects fuel preheating, fuel ignition, the speed of propagation, the intensity of the line of fire and smoke production. However, its calculus is complicated because an effective evaluation must consider changes in environmental conditions. This makes difficult a fast and precise enough for operative purposes, or for decision making in fire management. Therefore, the objective of this work was to generate practical models to calculate moisture content of 1 hour and 10 hour forest fuels. These were based on variations of relative humidity and temperature, which were monitored when prescribed burns were applied in four forest ecosystems (pine-oak, pine scrubland, pine, grass land-pine). Results suggest that relative humidity is the variable that better estimate the moisture content (R2 = 0.955 for 1-hour fuels; and R2 = 0.965 for 10 hours fuels). The generated information could be useful for several purposes, such as definition of fire risk areas, fire behavior estimations, prescription of burn planning, etc. Finally, it is suggested to carry on studies in order to assess temporal variations of fuels moisture content.