Pre- & Post-Flood Analysis Using SAR Imagery

October 8, 2023 Flood Event – Matara District, Sri Lanka

Project Overview

This project assesses the extent and impact of the severe flood that occurred in Matara District on October 8, 2023. Pre- and post-flood Sentinel-1 SAR imagery was analyzed to delineate flood extents, assess affected land use, and evaluate impacts on infrastructure for disaster management planning.

Study Area

The study focuses on Matara District, located along Sri Lanka’s southern coast. The district is susceptible to heavy rainfall and river overflow, particularly from the Nilwala River, making it prone to flooding in low-lying areas and river-adjacent settlements.

Study Area Map of Matara District

Data Sources

Methodology

Pre- and Post-Flood Maps

Pre-Flood Condition - Matara District

Pre-flood condition map showing baseline water distribution before the October 8, 2023 flood event.

Post-Flood Condition - Matara District

Post-flood map highlighting inundated areas and river overflow during the flood event.

Flood Extent Map - Matara District

Flood extent map showing spatial distribution of water-covered areas across the district.

Pre-Flood Land Classification - Matara District

Land classification map before the flood event, depicting vegetation, croplands, built-up areas, and rangelands.

Post-Flood Land Classification - Matara District

Post-flood land classification map showing inundated vegetation and cropland areas affected by the flood.

Flood Impact on Infrastructure - Matara District

Map highlighting flood-affected infrastructure including roads, railways, and educational facilities.

Key Observations

Tools & Skills

Conclusion

The project demonstrates the use of SAR imagery for accurate flood assessment, providing insights into affected areas, infrastructure, and land use. The maps support disaster management planning and highlight the importance of integrating remote sensing and GIS for flood preparedness and mitigation.