Accurate and spatially distributed precipitation data are fundamental to effective water resource management. In Morocco, as in other arid and semi-arid regions, precipitation exhibits significant spatial and temporal variability. Indeed, there is an intra- and inter-annual variability and the northwest is rainier than the rest of the country. In the Bouregreg watershed, this irregularity, along with a sparse gauge network, poses a major challenge for water resource management. In this context, remote sensing data could provide a viable alternative. This study aims precisely to evaluate the performance of four gridded daily precipitation products: three IMERG-V06 datasets (GPM-F, GPM-L, and GPM-E) and a reanalysis product (ERA5). The evaluation is conducted using 11 rain gauge stations over a 20-year period (2000–2020) on various temporal scales (daily, monthly, seasonal, and annual) using a pixel-to-point approach, employing different classification and regression metrics of machine learning. According to the findings, the GPM products showed high accuracy with a low margin of error in terms of bias, RMSE, and MAE. However, it was observed that ERA5 outperformed the GPM products in identifying spatial precipitation patterns and demonstrated a stronger correlation. The evaluation results also showed that the gridded precipitation products performed better during the summer months for seasonal assessment, with relatively lower accuracy and higher biases during rainy months. Furthermore, these gridded products showed excellent performance in capturing different precipitation intensities, with the highest accuracy observed for light rain. This is particularly important for arid and semi-arid regions where most precipitation falls under the low-intensity category. Although gridded precipitation estimates provide global coverage at high spatiotemporal resolutions, their accuracy is currently insufficient and would require improvement. To address this, we employed an artificial neural network (ANN) model for bias correction and enhancing raw precipitation estimates from the GPM-F product. The results indicated a slight increase in the correlation coefficient and a significant reduction in biases, RMSE, and MAE. Consequently, this research currently supports the applicability of GPM-F data in North Western Morocco.

Groundwater is essential for drinking and irrigation to ensure a stable life and economic development, especially in semi-arid to arid rural areas such as the Lagnadiz district in central Morocco. However, its occurrence is highly variable in discontinuous media because of its uneven circulation along fractures, making it difficult to locate productive drilling sites. This study aimed to identify suitable locations for the establishment of productive wells by combining Sentinel-1 and Sentinel-2 imagery, a DEM, and geological data. Lineaments were automatically extracted and validated using Google Earth imagery, slope and hillshade maps, and field observations. Six thematic layers (lithology, drainage density, distance to faults, slope, lineament density, and lineament intersection density) were weighted using the Analytic Hierarchy Process and integrated through Weighted Linear Combination. The resulting groundwater potential map shows that high potential areas cover 38.53% of the study area, followed by moderate potential areas (34.84%) and low potential areas (26.63%). A ±10% weight sensitivity analysis showed strong map stability, with r values of 0.9949–0.9999 and class agreement rates of 93.31–99.61%. The map was independently validated using exploitation-yield data from 22 boreholes that were not involved in its construction. Using a productivity threshold of 5 m³/h, the ROC analysis produced an AUC of 0.795, with a 95% confidence interval ranging from 0.581 to 0.949, indicating an acceptable ability of the GWPI map to distinguish between the two productivity groups.