GIS and evaluation of spatial rainfall interpolation techniques between 1980 and 2019: Application to the Oued Oum Er-Rabia sub-watershed (Central High Atlas, Morocco)

The aim of this paper is to analyze, describe and evaluate the different spatial interpolation techniques using GIS. Such as Inverse Distance Weighting (IDW) and Radial Base Function (RBF), which are deterministic methods, and two probabilistic methods: Ordinary kriging (OK) and Universal kriging (UK), they have been applied to 25 rainfall stations in the catchment area of Oued Oum Er-Rabia, located in the center of Morocco. Analyses of these methods showed that the UK and OK methods were more optimal than the IDW and RBF deterministic methods, and that the UK method had better results than the OK method. Also, the IDW method has better results than the RBF methods (UK> OK> IDW> RBF); the UK, OK, IDW and RBF methods have results 96.0815, 96.9056, 100.1564 and 100.489 % respectively for RMSE, and results decreased for the coefficient of determination (R2 value).