How can natural disasters affect a country's development?
It depends on if the natural disasters are regular or irregular and how developed the country is.
If the country receives regular natural disasters then that country will eventually (if they have the money) create ways to predict and prevent/prepare for the disasters. This would change how structures will look, how the people must know, how funding will be used, and the environment around them would change as well.
If it is irregular, but the country has money then, it will cause that country to fund clean up and repairs for the structures, homes, roads, etc. lost in the disaster. However, this version does not affect the development as much as regular disasters, because there is no reason to prepare or predict if it is irregular.
Lastly, if the country is not developed and has regular disasters then it could potentially keep the country in poverty. Obviously it is different in different situations and places, but as long as the repairs and replacements can not be done, then people will either live in those areas expecting no help from the government and having to use tools by themselves in order to restore their homes and buildings. This makes it difficult for civilization since the technology will not be as advanced, therefore predicting the disaster will be harder or less accurate. The other option is that no one will live there creating less opportunities for the country to develop.
I hope this helps, but I am not an expert so I am sorry if there are mistakes.