Wildfire Dynamics on the Kinburn Peninsula, Ukraine, Using Sentinel-1 SAR and Optical Data (2022–2025)

Abstract. Since 2022, the Kinburn Peninsula, Ukraine, has been located within an active war zone, where frequent and recurrent wildfires have affected heterogeneous coastal sandy ecosystems. Burned-area mapping in this landscape is complicated by wetlands, salt flats, exposed sands, reedbeds, artificial pine plantations, cloud cover, smoke and restricted field access. This study applies an integrated multi-sensor approach to map wildfire damage and recurrence during 2022–2025 using Sentinel-1 SAR, Sentinel-2 and Landsat 8/9 optical imagery, NASA FIRMS thermal anomalies and official fire-monitoring materials. Optical burn indicators were used to identify spectral evidence of burning, while Sentinel-1 VV/VH backscatter changes and Radar Forest Degradation Index (RFDI) were used to detect structural vegetation degradation. Optical burn candidate masks and SAR-derived structural damage masks were spatially overlaid to delineate confirmed fire-damage areas. The results show that wildfire impact was spatially recurrent rather than isolated. SAR-derived candidate areas increased from 637.06 ha in 2022 to 4297.97 ha in 2025, while mean ΔVH remained consistently negative, indicating reduced vegetation volume scattering. The largest confirmed optical–SAR fire-damage area was detected in 2025, reaching 598.26 ha. Fire recurrence mapping revealed zones of accumulated pyrogenic stress, particularly within artificial forest plantations, psammophytic steppe complexes and protected coastal ecosystems. The proposed optical–SAR framework improves wildfire damage mapping under wartime and data-limited conditions.