Analysis of Meteorological Drought Using Satellite-based Rainfall Products over Southern Ethiopia

Abstract

The main objective of this paper was to analyze drought characteristics in terms of space and time using high-resolution satellite-based precipitation products for the 1991-2022 period in the regional state of Southern Nations Nationalities and Peoples of Ethiopia (SNNP). The satellite-based precipitation product used in this study was selected after the evaluation of the three satellite estimates namely: Africa Rainfall Climatology, version 2 (ARC2); Climate Hazards Group Infrared Precipitation with Stations (CHIRPS), and Tropical Applications of Meteorology using Satellite and ground-based observations (TAMSAT) against station-based rainfall for the study area space and time domain. The statistical metrics: Correlation coefficient (CORR), BIAS, probability of bias (PBIAS), mean error (ME), mean absolute error (MAE) root mean square error (RMSE), and Nash–Sutcliffe efficiency coefficient (NSE) were used to compare and evaluate the satellite rainfall products. The CHIRPS shows the highest CORR of 0.96 and BIAS of 1.02, which is very close to the perfect value (BIAS=1), followed by TAMSAT. Hence, the CHIRPS-based precipitation estimate was used to assess the spatio-temporal patterns of meteorological drought based on the 3 and 12-month Standardized Precipitation Index (SPI). The results revealed successfully the known historical and recent droughts of 2022, 2021, 2014, 2015, 2010, 2009, and 2000. A high intensity and severity of drought was noted in SPI-3, while the least occurrences of extreme events were recorded in SPI-12. Severe drought situations were detected in the drought-prone areas in the southern and southeastern parts of the SNNP region.

Presenters

Tesfay Weldegerima
Assistant Professor, Faculty of Meteorology and Hydrology, Arba Minch University, Adis Abeba, Ethiopia

Details

Presentation Type

Paper Presentation in a Themed Session

Theme

Assessing Impacts in Diverse Ecosystems

KEYWORDS

METEOROLOGICAL DROUGHT, SATELLITE RAINFALL, CHIRPS, STANDARDIZED PRECIPITATION INDEX, SOUTHERN ETHIOPIA