The lightning-rainfall relationship for the flash flood events in Johor, Malaysia

Abstract

Flash flood is one of Malaysia's most severe natural disasters, causing major casualties and economic losses due to two local seasonal monsoons. Research shows the possible correlation between lightning events and heavy precipitation associated with flash floods. This study aims to discover the relationship between the number of lightning occurrences with the amount of rain in 24 hours. This study analyzed 5 flash flood events within a 100 km radius from Universiti Teknologi Malaysia, Johor, recorded from 2013 until 2017. The lightning data is obtained from Tenaga Nasional Berhad Research (TNBR), while rainfall data is received from the Department of Irrigation and Drainage (DID). The results show that the r-values between lightning and rainfall range from 0.6 to 1.0. The different values due to the number of lightning and rainfall occurrences are inconsistent for each case. It is also shown that 2 hours before the events, the number of lightning increases during a rainfall event is related to rainfall rate.