The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
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Articles | Volume XLIII-B3-2020
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIII-B3-2020, 641–648, 2020
https://doi.org/10.5194/isprs-archives-XLIII-B3-2020-641-2020
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIII-B3-2020, 641–648, 2020
https://doi.org/10.5194/isprs-archives-XLIII-B3-2020-641-2020

  21 Aug 2020

21 Aug 2020

A FUSION APPROACH FOR FLOOD MAPPING USING SENTINEL-1 AND SENTINEL-2 DATASETS

B. Tavus1, S. Kocaman1, H. A. Nefeslioglu2, and C. Gokceoglu2 B. Tavus et al.
  • 1Dept. of Geomatics Engineering, Hacettepe University, 06800 Beytepe Ankara, Turkey
  • 2Dept. of Geological Engineering, Hacettepe University, 06800 Beytepe Ankara, Turkey

Keywords: Natural Hazards, Sentinel-1, Sentinel-2, Flood Mapping, Ordu (Turkey)

Abstract. The frequency of flood events has increased in recent years most probably due to the climate change. Flood mapping is thus essential for flood modelling, hazard and risk analyses and can be performed by using the data of optical and microwave satellite sensors. Although optical imagery-based flood analysis methods have been often used for the flood assessments before, during and after the event; they have the limitation of cloud coverage. With the increasing temporal availability and spatial resolution of SAR (Synthetic Aperture Radar) satellite sensors, they became popular in data provision for flood detection. On the other hand, their processing may require high level of expertise and visual interpretation of the data is also difficult. In this study, a fusion approach for Sentinel-1 SAR and Sentinel-2 optical data for flood extent mapping was applied for the flood event occurred on August 8th, 2018, in Ordu Province of Turkey. The features obtained from Sentinel-1 and Sentinel-2 processing results were fused in random forest supervised classifier. The results show that Sentinel-2 optical data ease the training sample selection for the flooded areas. In addition, the settlement areas can be extracted from the optical data better. However, the Sentinel-2 data suffer from clouds which prevent from mapping of the full flood extent, which can be carried out with the Sentinel-1 data. Different feature combinations were evaluated and the results were assessed visually. The results are provided in this paper.