Assessment of GPM-IMERGV06B Precipitation Product against Gauge Data across a semi-arid watershed in Morocco

Abstract:

The availability of global scale satellite-based precipitation products (SPP) enables a wide range of applications from specifically studying the precipitation characteristics to several applications in domains such as hydrology, weather and climate studies, especially in regions with sparse and scarce data accessibility. Considering, highly varied performance of SPPs across space and time, it becomes important to study its applicability before using it in real-time for applications. The objective of this study is to perform statistical and hydrological evaluation of the recent, Integrated Multi-satellitE Retrievals for GPM (IMERG) products, a global high‐resolution satellite precipitation product (0.1°, 30 min) across a semi-arid watershed in Morocco using a ten-year dataset (2000–10) from 7 rain gauges. . First, the statistical validation using categorical and quantitative indices, such as, the proportion correct (PC), the probability of detection (POD), the frequency bias index (FBI), 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 is performed. Secondly, to study the reliability of this data as forcing driver to hydrological modelling, Soil and Water Assessment Tool (SWAT) a semi-distributed model is used, to simulate the streamflow. The initial assessment shows promising results in utilizing IMERG for hydrological applications across a semi-arid watershed in Morocco.