Application of Geographic Information Systems (GIS) for Analyzing Residential Damage Caused by Cold Lahar Floods in Sungai Pua and Canduang Districts

Abstract

Cold lahar floods originating from Mount Marapi have caused substantial landscape changes and residential damage, underscoring the need for reliable spatial information to support post-disaster management. Although previous research has primarily addressed hazard mapping and affected-area delineation, integrated assessments combining change detection with spatial analysis of residential damage remain limited. This study analyzed the extent and spatial pattern of residential damage in Sungai Pua and Canduang Districts. A descriptive quantitative approach integrating geographic information systems (GIS) and remote sensing was employed. Pre- and post-disaster Sentinel-2 imagery was analyzed using the Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-up Index (NDBI), Maximum Likelihood Classification, Post-Classification Comparison, and Ripley’s K-function. The analysis was supported by field verification of 114 affected buildings. The ΔNDVI-based affected areas accounted for 66.3% of Sungai Pua and 54.9% of Bukik Batabuah. Field observations identified 64 lightly damaged, nine moderately damaged, and 41 severely damaged buildings. Residential damage in Sungai Pua exhibited a significant clustered pattern across distances of 60–600 m, whereas Bukik Batabuah generally displayed a random pattern with localized clustering at 50 m. These findings demonstrate that integrating GIS, multitemporal satellite imagery, spatial point-pattern analysis, and field verification provides a robust approach to post-disaster residential damage assessment. This integrated framework can support targeted recovery measures and risk-sensitive settlement planning in areas exposed to future lahar floods.