This video demonstrate the easy and reliable method for mapping the flood area using ArcGIS with only raster calculator. I used only the near infrared band for identifying the flooding area due to the lowest reflection value from water. Also, to identified the change area I multiplied the first image with 10 and plus the value of second image so that the output will be have the value as:
11 Water in 2020 &2015 ,
10 Water in 2020 only,
1 Water in 2015 only,
0 No water in both year.
The study area in this video is a reservoir of Lower Sesan hydropower dam in Cambodia. It is the biggest dam in the country.