Spatiotemporal Characteristics and Trend Analysis of Two Evapotranspiration-Based Drought Products and Their Mechanisms in Sub-Saharan Africa

Drought severity still remains a serious concern across Sub-Saharan Africa (SSA) due to its destructive impact on multiple sectors of society. In this study, the interannual variability and trends in changes self-calibrating Palmer Severity Index (scPDSI) based Penman–Monteith (scPDSIPM) Thornthwaite (scPDSITH) methods for measuring potential evapotranspiration (PET), precipitation (P), normalized difference vegetation index (NDVI), sea surface temperature (SST) anomalies were investigated through statistical analysis modeled remote sensing data. It was shown that scPDSIPM scPDSITH differed representation drought characteristics over SSA. The regional trend magnitudes scPDSI SSA 0.69 0.2 mm/decade (scPDSITH), with values attributed choice PET method used. remotely sensed-based P NDVI showed wetting drying period 1980–2012 coefficients 0.12 (0.002 mm/decade). increased events semi-arid arid regions same period. A correlation revealed strong relationship between both monsoon pre-monsoon seasons. SST indicated significant positive negative relationships. This study has demonstrated applicability data sources assessment provides useful information predictability mitigation strategies.