Study of trends and mapping of drought events in Tunisia and their impacts on agricultural production.

The objective of this research is to explore spatial extent and temporal pattern of historical droughts and their impacts on agricultural production in Tunisia. This contribution was based on monthly rainfall series recorded from September 1973 to August 2016 in 16 main meteorological stations in Tunisia. The Standardized Precipitation Index (SPI), the Reconnaissance Drought Index (RDI) and the annual Potential Evapotranspiration (PET) were computed and used to characterize the gravity of climatic events and their spatial and temporal variations. A database of strategic crop productions and Agricultural Gross Domestic Product (AGDP) variation has been collected from FAO's official website. Based on SPI and RDI, strongly correlated indices (R = 0.99; p < .05), it is demonstrated that Tunisia has experienced several multi-year droughts (3 to 7 years) with different severities. During 1981, Tunisia suffered a generalized drought. However during 1996, severe to extreme humidity was observed over 70% of Tunisian territory (SPI and RDI values >1.5). Series of normal or near-normal years were recorded during 50% of the study period. Variation in cereal production showed the strongest correlation with RDI (R = 0.66), followed by olive oil (R = 0.45) and citrus fruits (R = 0.43). The outputs of this research could be useful for main stakeholders to identify compromised measure (subsidies, insurance) improving management of agricultural activities to mitigate drought impacts at farm level and over production zones.