Monthly, Seasonal, and Annual Variations of Precipitation and Runoff Over West and Central Africa Using Remote Sensing and Climate Reanalysis

Precipitation and runoff variability over West and Central Africa is the major challenge of water resource management, which drives a range of socio-economic issues. Storm water runoff poses serious environmental problems and public health issues in these regions. We use descriptive statistics in order to analyze monthly, seasonal, and annual runoff and precipitation using the Global Precipitation Climatology Project (GPCP) and the Fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) (ERA5) datasets, respectively for the period 1981-2021. Based on the results, the climate of the western zone is different from that of the equatorial zone, where runoff is persistently high throughout the year. Monthly and seasonal runoff show that June, July and August have higher runoff values. The high values for these three months correspond to the rainy season in these regions. Trends of the runoff and precipitation are detected using Mann-Kendall test. Apart of the coastal zones where trends are positive, trends in runoff are mostly negative throughout the Western and Central African regions. The result will benefit our understanding of the increasing suffrage of the local population from severe floods, landslides and soil erosion over this region.