SPATIAL VARIATION OF CLIMATIC HAZARDS IN THE NORTHERN REGION OF SRI LANKA

Abstract

There are no discernible patterns concerning drought and flood hazards in Sri Lanka; some areas have experienced more disasters than others. The objective of this study is to identify the spatial patterns of drought and flood hazards that exist in this region. Monthly, seasonal, and annual climatic data were gathered from thirteen stations, covering the period from 1972 to 2022. The Standardized Precipitation Index (SPI) was employed to examine each station's drought and flood hazards from 1972 to 2022. The Arc GIS 10.4 Krigging method was utilized to identify the spatial variations of the drought and flood hazards. During the South West Monsoon Season, severe droughts were detected in Vavunikkulam, Akkarayankulam, Murunkan, and Pavatkulam. Extreme floods were common during the First Inter Monsoon Season; three occurrences were noted at Iranaimadu, Thirunelveli, Pallavarayankaddu, and Nainathivu stations in the Northern region, identified through the SPI method. During the Second Inter Monsoon Season, two extreme floods in Thirunelveli, two in Vavuniya, and three in Murungan and Akkarayankulam stations were identified alongside seven severe droughts at Nainathivu and five at Vavuniya. During the North East Monsoon Season, three severe floods were identified in Akkarayankulam, three in Ambalapperumalkulam, three extreme floods in Pallavaraykaddu, three severe floods in Muththaiyankaddu, four severe floods in Vavunikkulam station, and three severe floods in Vavuniya in the Northern region of Sri Lanka. Some areas in the Northern Region of Sri Lanka have been affected several times spatially by both floods and droughts. The eastern parts of the study area have more flood hazards, while the western parts have more droughts, according to 70% of the people surveyed. Furthermore, the frequency of flood occurrences decreases gradually in the direction from east to west, while that of droughts decreases gradually from west to east.