Geoinformatics-Based Flood Extent Mapping and Analysis Using Sentinel-1 Imagery: A Case Study of Phayao Province

Climate change will worsen global flooding. This study used geoinformatics and Sentinel-1 satellite data to map and analyze flood extent in Phayao Province, Thailand. The research defines the area of interest, preprocessing satellite imagery, identifying flood extent, and validating results. Phayao Province was inundated for 19,295.87 hectares on August 25, 2024. Further analysis showed that the flood extent changed over the study period, down to 10,620.52 hectares on September 6 and up to 11,990.81 on September 18. Dok Kham Tai, Chiang Kham, and Chun were most affected by the flooding. The researchers identified places with repeated flooding episodes using satellite imagery from multiple time, estimating the inundated area at 390,964.16 hectares. The results showed that geoinformatics and remote sensing can quickly and accurately flood extent mapping for evidence-based disaster management and mitigation. This study can be applied in similar flood areas to enhance awareness of flooding patterns and design flood risk management measures.