Surviving the Aftermath

I don't know the exact triggers for these, but I did it in a custom game. Occasionally, a new quest would be available from the campsite/city center. After accepting, all you need to do is go to each location on the world map with an appropriate specialist. If you are exploring a location, you want to bring a scavenger or scientist, but if you are fighting, then you want to send a fighter. After every location is dealt with, the achievement will pop.