The gridded daily precipitation data from PISCO v2.1 and ERA5 are evaluated by applying the GR4J hydrological model to generate daily flows in the sub-basins located upstream of the Cahua hydrometric station, in the upper Pativilca River basin, under a semi-distributed approach by sub-basins. The RS Minerve platform is used for the construction of the semi-distributed hydrological model. 33 sub-basins upstream of the Cahua hydrometric station were identified using QGIS software. The gridded precipitation data from PISCO v2.1 and ERA5 were validated based on 14 rain gauge stations located in the study basin and nearby areas, with historical precipitation records that were statistically analyzed to assess their reliability. When applying the semi-distributed sub-basin GR4J hydrological model, in the calibration stage (2000-2010), a Nash-Sutcliffe value of 0.76 was obtained using the daily...