Exploration of CHIRPS Satellite Data as Rainfall Estimation Data in Medan City and Deli Serdang Regency

The availability of spatially and temporally consistent rainfall observation data is needed in various fields. Fields of research related to hydrometeorology are no exception. The limitations of rainfall measuring tools and stations encourage the use of alternative rainfall data derived from estimates based on satellite data. The condition of limited tools and stations to measure rainfall is also experienced in Medan City and Deli Serdang Regency. This study aims to test how far the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) satellite rainfall data can be used as standard rainfall data in Medan City and Deli Serdang Regency. In this study, monthly rainfall forecasts from CHIRPS satellite data are validated by rainfall observations from four station locations. Validation is carried out to determine the level of correlation and the magnitude of the error value from satellite data. The method used is descriptive statistics by calculating the correlation coefficient and error value. The validation results show that the CHIRPS satellite data has a fairly strong correlation greater than 0.6 with observation data from four locations. Therefore, CHIRPS satellite data can be used as an alternative to rainfall data in Medan City and Deli Serdang Regency, especially in areas with the same elevation and topographic conditions as the station location, with the best validation results.