Assessment of preselected Satellites and Reanalysis Precipitation Products using ground observations over the Upper and the Middle Drâa catchment, central-east of Morocco.

<p>In most ungauged areas, validation of precipitation gridded satellite products is fundamental to provide precipitation information with high accuracy and spatial-temporal resolution. Dr&#226;a river basin (DRB) in southeastern Morocco is one of ten driest watersheds worldwide with a limited network of rain-measured stations. However, literatures investigations have shown the necessity of strong climatic datasets to conduct water resources management. In this study, five satellite precipitation products with high spatio-temporal resolution were evaluated including: the latest version of Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS V2.0), the atmospheric reanalysis dataset for the global climate by the ECMWF (ERA5-Land), the latest version of Multi-Source Weighted-Ensemble Precipitation (MSWEP V2.2), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System-Climate Data Record (PERSIANN-CCS-CDR) and Tropical Applications of Meteorology using SATellite data and ground-based observations (TAMSAT V3.1). The evaluation was conducted in terms of their performance in capturing occurred precipitation events and reliable amounts. The Monthly and seasonal precipitation amounts determined by these products at different altitude levels were evaluated against available rain gauge observations for a period of 81 months using point-to-pixel method and with reference to continuous, categorical and volumetrics indices. The only available station belonging to SYNOP weather network (Surface Synoptic Observations) with more than 40 years of data was included to advance our conclusion regarding the performance of a given P-dataset. The achieved results show that the best performance was obtained for ERA5-Land and MSWEP V2.2 for monthly and seasonal time-step, respectively, while CHIRPS V2.0 followed by TAMSAT V3.1 and PERSIANN-CCS-CDR perform the worst. The expected results will cover the performance of each P-dataset for different sub-seasons, elevation, intensities and their ability to detect extreme rain events. The outcomes of this investigation provide valuable information in one of the most scarcely gauged and arid Moroccan watersheds, indicating which P-dataset could be an alternative to rain gauges measurement.</p> <p><strong>Key words</strong>: Dr&#226;a river basin (DRB), ungauged arid areas, precipitation satellite products, ground observations.&#160;</p>