Danang Ariyanto, A'Yunin Sofro, Riskyana Dewi I. Puspitasari, Riska Wahyu Romadhonia, Hernando Ambao
This research aims to apply the co-kriging spatial interpolation method to estimate the distribution of rainfall in the city of Surabaya, Indonesia, and compare the results using different exogenous variables. The data used includes rainfall data from January to April 2024 for each sub-district in the city of Surabaya and its surroundings, as well as data on land area and altitude as secondary variables. Co-kriging is a geostatistical method that combines information from the main variable (rainfall) and one or more secondary variables (such as height and land area) to produce more accurate estimates than conventional interpolation methods. Spatial autocorrelation analysis was also carried out to check for spatial correlation in the data. The results of this research show that the altitude variable as an exogenous variable provides a model with a smaller RMSE value. This research is expected to provide a better understanding of the distribution of rainfall in the city of Surabaya. © 2025 Author(s).
Actuarial Science Study Program, Surabaya State University, Surabaya, Indonesia; Data Science Study Program, Surabaya State University, Surabaya, Indonesia; Matematics Study Program, Surabaya State University, Surabaya, Indonesia; Statistics Program, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
