A pair of new studies say that more people than ever lie in harm’s way from earthquakes, droughts, floods and other disasters, largely because of a surge in urban populations in developing countries.

Smaller or poorer countries can be devastated by disasters that are relatively inconsequential in places shielded by size or wealth, said one of the reports, a United Nations study that is being released Sunday in Bahrain.

That study, the Global Assessment Report on Disaster Risk Reduction, compared the impact of cyclones in the Philippines and Japan, for example. While more people in Japan are exposed to cyclones, the estimated annual death toll from such storms is 17 times higher in the Philippines, the study said.

Yet the report’s authors concluded that the level of vulnerability does not always mirror economic conditions, with high rates of disaster losses seen in a mix of developing countries with growing or weak economies.