Detection of flood inundation in serayu watershed using landsat-8 and sentinel-2 satellite imagery

Abstract

Floods are natural disasters that occur routinely almost every year in various regions in Indonesia, especially on the island of Java. According to the National Disaster Management Authority (BNPB), in 2001-2021 there were 5542 floods in Java. Determining the area of flood inundation is very important to know the potential and risk of the impact of flooding in an area. The purpose of this study is to develop a method of detecting flood inundation areas based on Landsat-8 and Sentinel-2 satellite imagery data using the Normalized Difference Water Index (NDWI) parameter. The Maximum Likelihood Classification (MLC) method was chosen to classify inundated areas and non-flooded areas. The Landsat-8 and Sentinel-2 satellite images were selected during the wet months that usually rain, January, February, March, November and December in 2020. The results show that the Landsat-8 satellite can detect water inundation better than the Sentinel-2 satellite. The results are influenced by the difference in recording time between the two satellites, the presence of clouds that cover the research location, and Landsat-8 imagery data that does not cover the entire location area.