The temporal evolution of drought events characteristics is discussed. Data from observations and simulations of the regional climate model RCA4 MPI-ESM-LR under two Representative Concentration Pathways (RCPs) scenarios for the period (1941–2100) are used. An amplification of drought frequencies is projected in the future under the RCP8.5 scenario. The maximum duration is expected to hardly change under the RCP8.5 scenario or even to decline.

The downward of rainfall trend occurred in the study area in 1972, affecting a few coastal stations. In 1976, this decline extended to the South West and throughout the coastal region. In 1980, the drop covered the entire basin. This decline has resulted in an estimated deficit of 30 % on average in the eastern region, the coastal region and the Mina. However, the central part of the basin experienced a 20 % decrease compared to the period before the break (1968–1980).