Development of a flood water level estimation method using satellite images and a digital elevation model for the Mekong floodplain. Issue 2 (25th January 2019)

• Record Type: Journal Article
• Authors: Tanaka, Kenji; Fujihara, Yoichi; Hoshikawa, Keisuke; Fujii, Hideto
• Is Part Of: Hydrological sciences journal. Volume 64:Issue 2(2019)
• Page Start: 241
• Page End: 253
• Publication Date: 2019-01-25
• Subjects: lower Mekong River -- flood water level -- floodplain -- synthetic aperture radar images -- optical images -- digital elevation model; Hydrology -- Periodicals; 551.4805
• DOI: 10.1080/02626667.2019.1578463
• Languages: English
• ISSNs: 0262-6667

Abstract

ABSTRACT: We have developed a flood water level estimation method that only employs satellite images and a DEM. The method involves three steps: (1) discriminating flood areas and identifying clumps of each flood area, (2) extracting the edges of the identified flood area using a buffering technique, and (3) performing spatial interpolation to transform the extracted elevation to flood water levels. We compared the estimated flood water levels with the observed ones. The RMSE using the RADARSAT was 1.99 and 1.30 m at river and floodplain points, respectively, whereas the RMSE using the MODIS was 4.33 and 1.33 m at the river and floodplain points, respectively. Given that most errors are attributed to the DEM, the method exhibited good performance. Furthermore, the method reproduced the flow directions and flood water level changes during the flooding period. Thus, we demonstrated that the characteristics of flood inundation can be understood even when ground observation data cannot be obtained.