Mapping Extreme Rain Conditions in Sumatra by Influence Global Conditions

3rd International Seminar On Sciences "Sciences On Precision And Sustainable Agriculture"

Supriyadi, S.^1,2 ; Hidayati, R.^1 ; Hidayat, R.^1 ; Sopaheluwakan, A.^2

Bogor Agricultural University, Faculty of Mathematics and Natural Sciences, Building Wing, 19 Level 4, Bogor, Indonesia^1

Indonesian Agency for Meteorology Climatology and Geophysics (BMKG), Indonesia^2

关键词: Clustering analysis;    Correlation analysis;    Dipole mode indices;    Extreme weather events;    Global conditions;    Northern regions;    Southern oscillation index;    Spatial patterns;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/58/1/012041/pdf
DOI  :  10.1088/1755-1315/58/1/012041

来源: IOP

【 摘 要 】

Determination of the extreme value category with a specific threshold value for a region with diverse climate characteritics may lead to incorrect extreme characterization. This study aims to determine thresholds of extreme rainfall in Sumatra, identify its spatial patterns and occurence in Sumatra and examine the link between extreme weather events to global climate phenomena which are the ENSO and the Dipole Mode. The data used in this study are daily rainfall data from 38 stations in Sumatra and indices of global climate phenomena, the dipole mode index (DMI) and the Southern Oscillation Index (SOI). The method used to determine the threshold for extreme value is with a probability of 95% based on their corresponding distribution, cluster analysis and correlation analysis. The expected result is an extreme value for all parts of Sumatra, the extreme character of all clusters by time and region, as well as its relationship with DMI and SOI. Preliminary results obtained that extreme daily rainfall values ranged from 42.4 to 114.7 mm per day. Extreme daily rainfall for western region of Sumatra has an average value higher and more varied than the eastern region. Extreme daily rainfall over northern region has an average value higher and more varied than the southern region. Clustering analysis of 38 abservation stations with ward method gets 5 (five) clusters. At least 20 years long periods of ideal data are needed to find the threshold of extreme rainfall over Sumatra region. Threshold of extreme rainfall with long periods of different data showing different values for each station are sometimes larger or smaller that may be caused by different spread of the data for each station.