More people in Japan are living in areas with potential risks of flooding compared with two decades ago due to residential development on suburban fields, a study showed Monday.

The figure stood at around 35.4 million in 2015, up 4.4 percent from 1995, according to research by Yasunori Hada, an associate professor of regional disaster prevention at the University of Yamanashi in Yamanashi Prefecture.

The number of households in areas designated as flood-prone by central and local governments soared 24.9 percent, to about 15.3 million, in the same period, according to the study that was based on flooding hazard maps for fiscal 2011 and the national census, conducted every five years.