Is it based on a manga?
Yes. It’s based on Miyazaki’s manga, “Kaze no Tani no Nausicaä”. There are seven volumes in total, and the movie covers about the first two volumes. He started serializing the manga “Nausicaä” in the animation magazine “Animage” in 1982. At first, Miyazaki did not want to make “Nausicaä” into anime, since he wrote the manga to express something he couldn’t express with animation, and since the manga was still at an introductory stage. As a result, the story of the film was substantially changed from the one in the manga. To know more about the manga, visit Nausicaä manga page.