Investigation of Flash Flood Over the West Peninsular Malaysia by Global Positing System Network

Flash flood hazard in Kiang Valley becomes an annual problem among urban folks, especially during the winter monsoon. Three cases of flash flood have been identified in 2013 as a case 1 for 1 September, case 2 for 31 October and case 3 for 13 December. This paper discussed a variation of Global Positing System (GPS) Precipitable Water Vapor (PWV) responses to the amount of rainfall within pre, during and post of the flash flood event. Surface meteorological data from three meteorological stations were interpolated to the three GPS stations to accurately measure the PWV. The analyses revealed that the trend of GPS PWV was observed highest during the phase of flash flood, of which preceded by an extreme minimum peak in two to three days before the incident. The study also found a high level of GPS PWV was associated with the frequency of rainfall and spatial distribution of precipitation. The highest total of calm and light air were also contributed to the flash flood hazard. Based on the case studies, the high level of GPS PWV and wind gusts found contributed to the chance of flash flood disaster over the Kiang Valley.