By observing 2020 flood in my country.
Initially,
The valid informations of NASA are used in the application as the main source. And to verify the true problems occurring due to flood in bangladesh as well as neighbour countries.
https://drive.google.com/file/d/1xtPS7Sf2po6j0FcWUSbUMQBAXxxhFZTT/view?usp=sharing
https://earthobservatory.nasa.gov/images/18488/floods-in-bangladesh