Climate change has been a prominent issue in the last decade. Climate change on a global scale does not necessarily have the same effect in different regions. Rainfall is a crucial weather element related to climate change. Rainfall trends analysis is an appropriate step in assessing the impact of climate change on water availability and food security. This study examines rainfall variations and changes at West Kalimantan, focusing on Mempawah and Kubu Raya from 2000-2019. The Mann-Kendall (MK) and Sen's Slope estimator test, which can determine rainfall variability and long-term monotonic trends, were utilized to analyze 12 rainfall stations. The findings revealed that the annual rainfall pattern prevailed in all locations. Mempawah region tends to experience a downward trend, while Kubu Raya had an upward trend. However, a significant trend (at 95% confidence level) was identified in Sungai Kunyit with a slope value of -33.20 mm/year. This trend indicates that Sungai Kunyit will become drier in the future. The results of monthly rainfall analysis showed that significant upward and downward trends were detected in eight locations. Rainfall trends indicate that climate change has occurred in this region.

Variabilitas curah hujan sangat erat kaitannya dengan perubahan iklim di suatu wilayah dan analisisnya sangat berguna dalam mengukur ketersediaan air untuk pertanian khususnya padi sawah. Penelitian ini bertujuan menganalisis variabilitas curah hujan dan hubungan curah hujan tahunan terhadap produktivitas padi di Kalimantan Barat.  Lokasi penelitian difokuskan di wilayah Kabupaten Mempawah dan Kubu Raya dengan menggunakan data yang tersedia pada tahun 2000-2019. Analisis datanya menggunakan persamaan variabilitas dan dilanjutkan dengan analisis korelasi dan komposit. Hasil analisis menunjukkan bahwa variabilitas curah hujan tahunan di Mempawah dan Kubu Raya termasuk dalam kategori rendah. Nilai variabilitas bulanan menunjukkan rentang yang bervariasi dari rendah hingga ekstrem di setiap lokasi. El Nino memiliki dampak negatif yang kuat terhadap curah hujan pada periode Juni-Juli-Agustus (JJA) dan September-Oktober-November (SON), sedangkanLa Nina memiliki dampak positif yang kuat terhadap curah hujan pada periode Juni-Juli-Agustus. Pada periode Desember-Januari-Februari (DJF) dan Maret-April-Mei (MAM), El Nino (La Nina) memiliki efek terhadap peningkatan (pengurangan) curah hujan. Dipole Mode Positif memberikan dampak pengurangan curah hujan pada periode SON dan MAM. Dipole Mode Negatif memberikan dampak bervariasi pada curah hujan pada periode JJA, SON dan DJF. Hubungan signifikan antara curah hujan tahunan dan produktivitas padi hanya ditunjukkan di Sungai Kunyit dan Sungai Kakap. Hal ini mengindikasikan bahwa curah hujan tahunan secara umum tidak berpengaruh signifikan terhadap produktivitas padi di sebagian besar wilayah penelitian. ABSTRACTRainfall variability is closely related to climate change in a particular region and it is useful in estimating the water availability for agriculture, especially lowland rice. This study examines the rainfall variability and correlation between annual rainfall and rice productivity in West Kalimantan. The research location is focused on the Mempawah and Kubu Raya districts in 2000-2019. The variability equation accompanied by correlation and composite analysis was used in the analysis. The result shows that the variability of annual rainfall in Mempawah and Kubu Raya falls in the low category. Monthly rainfall variability values mark a range that varies from low to extreme at each location. El Nino had a substantial negative impact on rainfall in the June-July-August (JJA) and September-October-November SON period. While, La Nina had a positive impact on rainfall only in the JJA period. In the December-January-February (DJF) and March-April-May (MAM) period, El Nino (La Nina) has an anomalous effect on increasing (reducing) rainfall. Positive Dipole Mode gives the negative impact in the SON dan MAM period. Negative Dipole Mode has a varied impact on rainfall in the JJA, SON and DJF periods. The significant corellation between annual rainfall and rice productivity was shown only at Sungai Kunyit and Sungai Kakap. This indicates that the annual rainfall generally has no significant effect on rice productivity in most areas.