Analysis of Rainfall Variability and Shifts in Season in Relation to the Rice Cultivation Period in Sleman Regency

The research aimed to determine seasonal rainfall variability in Sleman Regency to determine shifts in season in Sleman Regency, and the relationship between the shift in season and rice cultivation period in Sleman Regency. The method was the coefficient of variation to determine seasonal rainfall variability. The shift in season was analysed in 10-year periods. The relationship between the shift in season and the rice cultivation period was analysed using the Chi-Square test. The result of this research showed that the rainfall variability in the dry season was higher than that in the rainy season in Sleman Regency from 1990-2019. The dry season in 2000-2009 came 10 days earlier in 6 subdistricts. The dry season in 2010-2019 was delayed in a period of 10-50 days. The rainy season in 2000-2009 came 20 days earlier in 7 subdistricts, delayed in a period of 10 days in 3 subdistricts. The rainy season in 2010-2019 was delayed in a period of 10 days in 8 subdistricts. The Chi-Square count was greater than the Chi-Square table, meaning that there was a relationship between shift in season and rice cultivation period in Sleman Regency.