Assessing the Socioeconomic Implications of Flood Risk in Ratnapura District, Sri Lanka

The core objective of this research is to leverage geospatial technology for assessing flood risk in Sri Lanka's Ratnapura district while also examining the socioeconomic ramifications of flood occurrences in the area. Situated in Sri Lanka's central highlands, Ratnapura faces significant flood vulnerability, notably during the Southwest monsoon period spanning from May to September. Through a comprehensive consideration of influential factors in flood occurrences and the utilization of the Multi-Criteria Decision Analysis method, a flood risk map of the Ratnapura district has been constructed using ArcGIS 10.3 software. Analysis of the flood risk map indicates that 15.4% of the district is classified as having a very high flood risk, while roughly 31.5% is deemed to have low risk. Furthermore, overlaying thematic layers for road networks, buildings, land use, and settlements with the flood risk thematic layer reveals that approximately 4,000 human settlements, 1,200 main buildings, 35 schools, 100,000 acres of cultivated land, and 190 kilometres of major roads are situated in areas characterized by very high flood risk. Consequently, this scenario presents various socioeconomic challenges, including loss of life, damage to infrastructure, destruction of crops, and harm to livestock. Therefore, it is imperative to introduce effective flood mitigation measures, develop comprehensive flood management strategies, and promptly implement them. This proactive approach is crucial for minimizing the socioeconomic impact of future flood events in the region.

flood risk, multi criteria decision analysis method, GIS, consistency ratio

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