RAINFALL PATTERN AND INTER-ANNUAL VARIABILITY ANALYSIS RELATED TO ENSO PHENOMENA IN TIMOR LESTE

• Main Author: T. T. FERNANDES MONIZ (NIM: 22412005); Pembimbing : Dr.rer.nat. Armi Susandi, MT , TERENCIO
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20570
• Institution: Institut Teknologi Bandung

This study is conducted to understand rainfall patterns and inter-annual variability associated with ENSO phenomenon and will be appled to the develop sector in Timor-Leste. This study uses rainfall data from 57 rain gauge stations (19502010) over Timor Leste. The analysis begins with PCA are then grouped by cluster. The influence of ENSO on rainfall patterns is analyzed by using running mean, and cross correlation between SOI index and rainfall patterns anomalies. Rainfall pattern variations are described by moisture transport data analysis ECMWF ERA-40 (1958-2001) for the monsoon regime and the transition in the Maritime Continent and domain area of research. This variable is also used to explain the influence of ENSO variability and its association with inter-annual rainfall patterns in Timor Leste. The results showed that the rainfall pattern in Timor Leste can be clustered to three groups, as monsoonal pattern A and sub pattern A1 and A2. Monsoonal rainfall pattern A has peak rainfall in January which includes the northern part of the study area, sub pattern A1 has peak rainfall in February, and sub pattern A2 with peak in May (MAM). MAM rain is supported by MAM moisture transport source from Arafura sea with a magnitude of 160-180 kg / m / s in the south stronger than the north which is only 0 -60 kg / m / s. The average correlation between SOI and anomalies inter-annual rainfall patterns A, A1 and A2 is 30% with a lag time 2-5 month for the A and A2, and lag time 0 for the A1. In case of El Niño and La Niña, rainfall pattern experienced decrease and increase monthly rainfall about 5-50% of normal and a shift forward or backward rainfall peak but no change in rainfall patterns A, A1 and A2 in the inter-annual time scales. This result can be applied to the development of agriculture sector, engineering (civil), and disaster. Rainfall patterns contribute to the zoning and management of agricultural commodities cultivation. Moreover, as a illustration of extreme water discharge measurement information for design work, it can be used as inputs for mapping areas vulnerable to drought and flooding in Timor Leste.