Identifikasi Karakteristik Kejadian Curah Hujan Ekstrem di Provinsi Sumatera Utara

Abstract

This research aims to identify the spatial and temporal characteristics of extreme rainfall events in North Sumatra Province during the period between 1991 and 2020. Following the recommended rainfall parameters by WMO, the frequency and intensity of rainfall were calculated using data from 50 rain-gauge stations distributed across North Sumatra, by which the data have undergone quality control tests to ensure data completeness. The spatial pattern was analyzed by mapping the climatological averages of the parameters, and the trend patterns were statistically analyzed using the non-parametric Mann-Kendall test. The research results indicated that extreme rainfall events with low frequency and intensity occur on the east coast, while areas with high frequency and intensity were found in mountainous regions. The temporal trend analysis, in general, showed non-significant trends dominating these areas. Rain stations with significant and consistently increasing trend in the coastal area include Sei Suka Deras, Bandar Klippa, Klambir Lima, Klumpang, Staklim Sumatera Utara, Tandem, Lobu Rampah, Kwala Bingei, Tanjung Jati, Helvetia, Bangun and Bangun Bandar while in mountainous areas only found in Pakkat. While rain stations with a significant and consistently decreasing trend in coastal areas include Rawang Baru, Bandar Betsy, Laras Emplasmen, and Tanjung Leidong while in mountainous areas only found in Sipahutar.