A regional assessment of wet/dry spells characteristics using RCPs scenarios in a semiarid region

Predicting and analyzing wet/dry spells characteristics are vital for an appropriate understanding of climate change and its impacts on water resources management, particularly in arid and semiarid regions. Based on the downscaled precipitation series retrieved from the large-scale outputs of CanESM2 climate model under RCPs scenarios, wet/dry spells characteristics were analyzed during 2011–2040, in one of the most vulnerable arid and semiarid basins located in the Southern Alborz region, Iran. The results suggest that the mean wet spells number decreases during the 2020s period under RCP 2.6, 4.5, and 8.5 scenarios, while mean dry spells number indicates increasing values for the near future compared with the baseline. Moreover, short-length wet spells are dominant, while dry spells with medium durations are prevailing in the study region. On the other hand, dry spells persistence is much higher than those of wet spells, although there is no significant difference among the average wet spells number. Furthermore, there is not any significant difference among the persistence of wet spells under various RCPs scenarios. These results illustrate that the risk of flood events will be alleviated in the region ,whereas the risk of longer droughts events will increase. The main findings of this study show that analyzing the characteristics of wet/dry spells can lead to more accurate and efficient strategies to have sustainable resources management under the changing climate.