Flood Risk Assessment and Environmental Change Analysis Using GIS and Remote Sensing

Floods can be very destructive natural hazard; it causes significant environmental, social, and economic impacts. Havza is a district in Northern part of Türkiye, experienced major flood events in May 1998 and May 2026, which emphasize the need of identify flood-prone areas and analyze the factors that influence flood vulnerability. The aim of this study is to asses flood risk and analyzes land use/land cover (LULC) monitoring derived from remote sensing data in Havza. Furthermore, topographic characteristics were also obtained from Shuttle Radar Topography Mission (SRTM) and Digital Elevation Model (DEM) using Geographic Information Systems (GIS). Hydrological analyses include slope and flow accumulation models, and these analyses were used to identify susceptible areas. It has been observed that the mean NDVI value increased from 0.4239 in 1998 to 0.7447 in 2026, indicating a substantial increase in vegetation cover. LULC classification results also showed that urban areas increased from 16% to 20% while agricultural land decreased 54% to 50% in approximately last 3 decades. 3-Dimensional (3D) terrain visualization and river corridor-based flood risk mapping revealed that low elevation valley floors and settlements located very near to stream channels, which is the most vulnerable areas of floods. The findings of this study demonstrate the effectiveness of integration of GIS and remote sensing, topographic analysis, and LULC change detection within a single framework for flood risk assessment and sustainable land management. The results provide valuable support for disaster risk reduction, urban planning, and future development strategies in Havza and similar watershed environments.