Statistical and hydrological evaluation of different remotely sensed and reanalysis precipitation products across a Mediterranean watershed (case study: Upper-Sebou, Morocco)

Rainfall as an important component of water cycle assessment and understanding, is not always accessible especially in developing countries such as Morocco. However, several other sources such as satellite and reanalysis products become available globally in the last decades.

This study aims to evaluate three widely used global high-resolution precipitation products; the Integrated Multi-satellitE Retrievals for GPM (IMERG) product, Tropical Rainfall Measuring Mission 3B42 Version 7 (TRMM 3B42V7) and National Centers for Environment Prediction-Climate Forecast System Reanalysis (NCEP-CFSR) across a semi-arid watershed in Morocco over the period 2000-2010. Two types of analysis have been carried out in this work. First, the statistical validation using categorical and quantitative indices, that is, the probability of detection (POD), the frequency bias index (FBI), the index of agreement (IOA), the false alarm ratio (FAR), the root-mean-square-error (RMSE), the mean absolute error (MAE), the coefficient of determination (R²), and the bias, at daily, monthly, seasonal and annual time scales with observed rain gauge data as reference. Secondly, to study the reliability of this data as forcing driver to hydrological modeling, Soil and Water Assessment Tool (SWAT) a semi-distributed model is used, to simulate the streamflow.

Due to existing water and ecological issues in developing countries as in North of Africa where generally agriculture is the economic pillar, in addition to limited studies in this region, we believe that this work will have a significant impact not just for hydrological studies but also for flood, drought and climate change impacts assessments.