Application Of Spi And Spei Indices For The Analysis And Evaluation Of The Drought Phenomenon In The Ain Oussera Plain, Algeria
Auteurs : Koussa Miloud .
Résumé
Drought appears to be one of the main natural factors contributing to the degradation of agricultural landscapes and economic frameworks. The occurrence of drought episodes becomes noticeable following a prolonged absence of precipitation; however, it is difficult to determine their onset, extent, and resolution. Therefore, the precise assessment of drought characteristics based on drought intensity, extent, duration, and geographic coverage presents significant complexities. In thisresearch, two commonly used drought indices the precipitation index (SPI) and the precipitation evapotranspiration index (SPEI) are used to assess the meteorological state of drought in Algeria's Ain Oussera Plain. The potential evapotranspiration (PET) required for SPEI evaluation was computed using the Thornthwaite methods.Water deficiency was detected during the specified period, characterized by a decrease in precipitation levels associated with an increase in potential evapotranspiration rates. To investigate the temporal fluctuations of various levels of dryness, the SPI and SPEI were calculated during periods of 3, 6, 9, and 12 months. The analysis's findings demonstrated that, on practically all temporal scales, the years 1983, 1989, 1991, 1995, 2003, 2017, and 2021 were drought times based on both indices, with a noticeable majority of normal and moderate drought classifications.
Mots clés
Drought ; SPI ; SPEI ; semiarid climate ; Ain Oussera ; Algeria
