Do natural disasters affect a country in a positive or negative way? If so, why?

It really depends on the natural disaster. If the natural disaster is so large that it destroys the whole country, then it is surely negative. However, if the natural disaster is of a scale that is "manageable", it can have beneficial results, even if there are some negative consequences. The reason for this is that people usually learn through suffering. Without hardship and challenges, people usually do not grow. So, for there to be natural character and moral excellence, there will need to be some sort of hardships. In this sense, natural disasters can produce some good things.