Multi-source precipitation products assessment on drought monitoring across global major river basins

Abstract

Increased availability of precipitation observational datasets allows for accurate drought detection, monitoring and forecast. Most studies have shown accuracy of various precipitation datasets on regional drought detection and/or monitoring, how they perform across different global river basins, however, is less understood. Here, we evaluate five popular precipitation products including GPM-IMERG, ERA5, GLADS, CPC and PREC/L for meteorological drought detection in 46 large river basins globally, by employing the Standardized Precipitation Index (SPI) at 3-month time scale (SPI-3). The results show that there is a large performance difference among these products. On the whole, GPM-IMERG and PREC/L are ideal precipitation datasets for drought monitoring in North America, South America and Asia, while GLDAS is better in Europe. In terms of specific mega drought events over major basins, all precipitation products perform well in capturing mega drought events overall, especially for the Yangtze, Danube, and Colorado river basins, with PREC/L having the highest accuracy. Specifically, PREC/L well captures the centroid and extent of the typical mega drought events over the Orange and Murray basins. The outcomes of this study can provide a deeper insight into applicability of various precipitation datasets in drought monitoring for different global river basins, which guides scientists and engineers to select suitable precipitation products and further better manage drought disasters.