Determination of equilibrium moisture content for several fine fuels in Hawaii

Equilibrium moisture content (EMC) is an intermediate variable used to predict fuel moisture content in the National Fire Danger Rating System (NFDRS) and in several fire behavior prediction tools in the United States. The equations used to predict EMC were developed from Sitka spruce data collected in the 1930s. Because EMC plays a critical role in fire behavior and danger calculations, EMC values have been determined for several nonwoody species on the U.S. mainland since the early 1970s. The focus of this earlier work was on fine fuels found in the western and southeastern U.S. EMC values have been derived for some Australian fuels as well. A high resolution version of the NFDRS is being implemented in the Hawaiian Islands. The version currently includes the existing fuel moisture equations for the NFDRS. Hawaii has a variety of fine fuel types that have not been previously tested to determine if EMC values are similar to Sitka spruce or to other fine fuels that have been previously studied. Results of a study determining equilibrium moisture content for several Hawaiian fine fuels and other selected fuels and comparing these data to existing data will be presented.