GIS-Based Flood Hazard Mapping in EravurPattu Divisional Secretariat, Batticaloa District, Sri Lanka

Abstract

In the recent past, Sri Lanka experienced heavy floods in the Eastern Province. The livelihoods of many households in the East are affected by flood frequently. The objective of this study was to create a flood hazard risk map of EravurPattu DS division based on flood occurrence, topographical, hydrological and population census data. Geographic Information System (GIS) is used in this study to identify the hazard zone by floods. Variables such as number of flood occurrence, population density, elevation and the distance between the water bodies and the flood occurred area were considered for this study. The knowledge-based ranking scheme was applied to each of the four variables. Indicators that represent a high-level impact across the GN division were given higher ranks. Priority was given according to the level of impact on each division. All the factors were assigned equal weights and final flood hazard index map was produced by weighted overlay technique using Arc GIS. The study revealed that 80% of GN divisions in EravurPattu can be categorized under high and very high flood hazard areas. This study recommends to undertake remedial measures on land use planning.