Occurrence of Flood and Risk Assessment in Batticaloa District, Sri Lanka Using Geospatial Technology

Suthakaran, S ¹, Rajendram. K², Zahir, I.L.M ³

^1&2 Department of Geography, Faculty of Arts and Culture, Eastern University Sri Lanka

³ Department of Geography, Faculty of Arts and Culture, South Eastern University of Sri Lanka

Correspondence: suthakarans@esn.ac.lk  

Abstract

This study investigated the occurrence of flood and risk assessment in Batticaloa District, Sri Lanka, using geospatial technology and open data from OpenStreetMap. The study analyzed the historical flood events in the district and assessed the flood risk using spatial analysis and modeling techniques. The study included collecting and analyzing data on land use, elevation, rainfall, and drainage systems, and combining them to create flood risk maps and also used open data from OpenStreetMap to improve the accuracy of flood risk maps by incorporating detailed information on infrastructure, buildings, and roads. The flood risk maps for Batticaloa District and identified the areas that are most vulnerable to floods. The results reveal that the level of higher, moderate and lower risk is 71.7, 28.6 and 76.7 sq. km respectively. Consequently, 76 Grama Niladhari Divisions are higher risk during the higher intensity of rainfall in Batticaloa District. Similarly, areas with low elevation, high rainfall, and inadequate drainage systems are at the highest risk of flooding. The incorporation of open data from OpenStreetMap improved the accuracy of the flood risk maps and provides detailed information on the location and vulnerability of critical infrastructure and buildings. Finally, the study provided improving flood risk management in Batticaloa District which included the implementation of flood risk reduction measures such as improving drainage systems, raising awareness about flood risk among the local community, and strengthening institutional capacity for disaster risk reduction. The study also emphasizes the importance of open data policies and the need for increased collaboration and data sharing among stakeholders involved in flood risk management.

Key words: flood, risk assessment, openstreetmap, vulnerable, modeling