Local calibration of meteorological forest fire danger indices in Jipijapa, Manabí, Ecuador

Abstract

The monitoring of forest fire danger through meteorological indices constitutes a key tool for preventive fire management. However, their effectiveness depends on their adaptation to local conditions. This study aimed to locally calibrate the Nesterov Index and the Monte Alegre Formula (FMA), two meteorological fire danger indices, in Jipijapa, Manabí, Ecuador. Historical weather data and fire occurrence records were used to develop locally adjusted danger scales, evaluating the distribution of the number of days per danger class and their correspondence with fire occurrence. The original scales exhibited distributions inconsistent with expected fire behavior, while the adjusted scales showed a decreasing trend in the number of days from lower to higher danger classes, and an increasing trend in fire occurrence. The values of skill score (SS) and percentage of success (PS) improved substantially after calibration: the Nesterov Index reached an SS of 0.0815 and a PS of 59.56%, while the FMA achieved an SS of 0.0806 and a PS of 53.54%. These results demonstrate shown that both indices, once calibrated, are applicable to the local context of Jipijapa. Nevertheless, the operational use of the FMA is recommended due to its computational simplicity. This study reinforces the need to adapt meteorological indices at the regional level to improve the accuracy of forest fire danger assessment and enhance preventive fire management strategies.