Hydro-Meteorological Disaster Incidents and Associated Weather Systems in Sri Lanka

Abstract

This paper presents a comprehensive seasonal analysis of disaster incidents with their associated weather systems happened in Sri Lanka since 1907 to 2019. Disaster incidents and weather records were collected from different reliable sources and analysed with the observed weather systems to understand the formation and development of the weather systems. According to the observations, frequent hydro-meteorological hazards experienced by the country are extreme winds, floods, and landslides. The seasonal analysis shows that majority of these hydro-meteorological disasters have occurred during the southwest monsoon, where the weather was mainly dominated by the monsoon winds entering from the southwest of Sri Lanka which creates torrential rainfall mainly in the wet zone of the country. The frequency of formation of depression and deep depression, from 1907 to 2019 shows that most of these are formed in the Bay of Bengal (BoB), North Indian Ocean, from October to January while having the highest frequency in November followed by December. The study will help to understand the possible damages, and thereby help the community to be prepared for such future hazards. The need for a central platform for generating timely impact-based warnings and helping the community to act was also identified. Further, the census block can be suggested as the smallest; Micro-Geographic Incident Response Unit (MG-IRU) to grant the decision-making power and connect the institution and community in the disaster risk management process.

Keywords: hydro-meteorological disasters, monsoon, tropical convergences, weather systems, preparedness