Use of standardized precipitation and evapotranspiration index (SPEI) from 1950 to 2018 to determine drought trends in the senegalese territory

Abstract

The management of water resources in our states has become increasingly difficult in recent times because of the frequency and intensity of droughts. In the context of climate change, extreme weather and climate events such as floods and drought, which are increasingly occurring, have a negative impact on the socio-economic development of the Senegalese territory. In this study, the Standardized Precipitation and Evapotranspiration Index (SPEI) was applied to characterize drought conditions in Senegal between 1950 and 2018. The SPEI was calculated from precipitation and temperature data for different periods of time. accumulation. Based on the SPEI, multi-scale models, trend and spatio-temporal extent of drought were evaluated, respectively. The results explicitly show a tendency to dry out Senegalese territory. The average SPEI values at five time scales all decreased significantly. Some moderate and severe droughts were recorded after 2005 and have even been aggravated. In examining the spatio-temporal extent, the aggravating condition of the drought has been revealed. To study the performance of SPEI, a correlation analysis was performed between the SPEI and the standardized precipitation index (SPI). The results showed that SPI and SPEI correlations were approximate and that SPEI could better monitor soil moisture than SPI in months with a significant increase in temperature.

Keywords: standardized index, SPEI, SPI, trend, drought