RELATIVE HUMIDITY AND WILDLAND FIRE IGNITION BY CIGARETTES

摘要

With the size and number of wildland fires in the U.S. this year, it is important to identify therntypes of ignition sources capable of igniting forest floor debris, and the conditions necessary for ignitionrnto occur. Often, cigarettes are discounted for their ability to ignite nearby fuels based on weatherrnconditions. While environmental factors will continue to be important in assessing wildland fuel ignitionrnachievement, the values of relative humidity which have been used by investigators to discount cigarettesrnas competent ignition sources have been historically underestimated in the literature. It has beenrnsuggested in the literature and in training materials provided to fire investigators that cigarettes cannotrnignite wildland fuels when relative humidity is above 25%. Recognizing that ignition achievement isrndependent upon several variables, including weather conditions; it was desired to assess the ability of arncigarette to act as an ignition source when the relative humidity was above 25%.