[math-fun] That can't be right!

Approximately six days ago, news organizations began reporting that, according to the United Nations, "one-fifth" of Pakistan was under water. Since then, the one-fifth has appeared again and again with assorted modifiers: up to, about, at least, etc. Looking at the Earth Observatory pictures... http://earthobservatory.nasa.gov/IOTD/view.php?id=45200 ... I am having a hard time seeing the reality behind that fraction. I've been unable to find the original UN source of the stories and I don't see a lot of skepticism out there. Perhaps by the "country" of Pakistan is meant something other than geographical shape but that is never explicitly stated. Anybody care to wade in?