If you have actually been involved in managing a disaster, or if you have been imagining being in that position, or if you have watched news reports about a natural disaster, it should not be that difficult to determine what "experiences" you had or might have had during that time.
How did you travel to arrive at the location of the disaster? If there were challenges with the process of arrival, that is the first experience to record. What type of housing did you have? Were there comforts missing from that housing - running water, hot water, electricity, privacy, hot food whenever you wanted it? All of these could be the basis of more experiences.
What, specifically, were your duties within the project? What did you experience while carrying out these duties? Did you have opportunities to work with people who had different ideas than yours? How did you work out your differences? Did you become involved in doing things that you never expected to do? How did that feel?
If you have reviewed a real disaster incident, you now need to put yourself into that situation. What would you have been seeing? smelling? feeling? doing? What were the immediate needs of the people who had been affected by the disaster? How would you have helped them meet those needs? You need to figure out what your experiences would have been, based on what the circumstances were like. Remember to add concerns for safety, since that is almost always an issue in those kinds of situations.