Comparative study from ground-based rain gauges vs. rainfall products at different time steps in the southeast of the Republic of Djibouti

Abstract

The Republic of Djibouti is a small country in the Horn of Africa and as for most regions of Africa, ground rainfall stations are sparse. This study aims to compare at different time steps (annual, monthly, and daily) 15 rainfall estimation products (P-datasets) to 5 reference ground-based rainfall stations, over the period of 1980–1990. To classify the reliability of these products, several metrics were considered, the Kling Gupta Efficiency (KGE) and the Heidle Skills Scores (HSS at daily time step). For the study area, 5 P-datasets present high KGE values at annual and monthly time step: EWEMBI, GPCC, JRA-55 Adj, MSWEP and WFDEI-GPCC; the best 5 performing products at daily time step are CHIRPS, EWEMBI, JRA-55 Adj, MSWEP and WFDEI-GPCC. To complete this comparative analysis, it will be necessary to perform an analysis at the watershed scale and on a new temporal window.