Utility of satellite-based precipitation products for drought monitoring over Morocco

Abstract

Satellite precipitation products (SPPs) offer valuable data for large-scale drought analysis, although their accuracy varies with climate characteristics and data processing algorithms. This study aims to comprehensively analyze the utility of two satellite precipitation products (SPPs) for drought monitoring over the entire Moroccan territory: the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) and the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), using the Standardized Precipitation Evapotranspiration Index (SPEI) at multiple spatiotemporal scales. Ground-based precipitation data from 27 stations (1987–2017) served as reference. The comparison of SPEIs derived from satellite and reanalysis data with ground-based SPEIs revealed strong correlations, though spatial variability was notable, especially in high-altitude areas. Correlation coefficients ranged from 0.32 to 0.92 for CHIRPS and 0.45 to 0.92 for PERSIANN-CDR. Bias was 50–60% for CHIRPS and 37–141% for PERSIANN-CDR, with monthly RMSE values of 10–40 mm and 7–48 mm, respectively. Both products effectively captured drought occurrence and trends, with PERSIANN-CDR showing particularly high accuracy in simulating events. Overall, CHIRPS and PERSIANN-CDR provide valuable insights for drought monitoring and management across Morocco.

Keywords

• Meteorological drought
• CHIRPS
• PERSIANN-CDR
• ERA5
• SPEI
• Mann–Kendall test