Rainfall effects on fine forest fuels moisture content

Abstract

The main purpose of the present study was to develop and test different approaches to predict fuel moisture content after rainfall episodes based on field measurements. These approaches were validated also with field measurements that indicate which as the best performance. It was also an objective to establish a low risk or safe period in terms of forest fires occurrence through the analyses of fuel moisture content after rainfall episodes comparatively to the value observed before the episodes. Although the influence of rainfall on forest fuel moisture content is quite complex we found that the simplified assumptions made in the present study and the simple mathematical models that were proposed exhibit suitable performances in the prediction of fuel moisture content change after rainfall episodes. In the present study good prediction results were obtain for dead foliage of the tree species of Pinus pinaster and Eucalyptus globulus. It was also verified that a safe time period regarding the occurrence of forest fires depending on the summer rainfall episode intensity could be established.