Monitoring drought conditions in Lebanon using climate-based indices

Abstract

Temperatures in Lebanon are projected to rise 4°C by the end of the 21st century, reaching unprecedented levels. Also, it has been projected that rainfall will be reduced by 10-20% by 2040 and between 25-50% by 2098. Consequently, Lebanon will be facing an increased risk of drought conditions. In this context, investigating proper drought indices for Lebanon is expected to help in improved policies and strategies to limit the socioeconomic and environmental impact of drought in Lebanon. Accordingly, the aim of this study was to evaluate drought conditions in Lebanon by investigating relevant climatebased drought indices. The specific objectives were to 1) review and identify a number of climate-based drought indices for use in Lebanon, 2) assess the spatial and temporal variation of current and future drought conditions in Lebanon, 3) evaluate the performance of calculated drought indices by employing data of fire occurrence and extent of burned areas, and 4) investigate the spatial distribution of future drought conditions in comparison to the existing Land Cover/Land Use map of Lebanon. Consequently, three drought indices were investigated. These included the KeetchByram Drought Index (KBDI), the Standard Precipitation Index (SPI), and Deciles. The KBDI was evaluated for all Lebanon; while the SPI and Deciles were calculated only for four locations (Mrah El Abed, Bazouriye, Kfarhay, and Bmahray). The main findings of the results showed that Lebanons natural environment is affected by an increasing trend of drought conditions. The evaluation of results showed high correlations of drought indices with fire data (number of fires and extent of burned area), and large forested areas being affected by increased drought conditions.