Japan is experiencing what could be one of the worst weather-related disasters in its history, following the heaviest rainfall the country has experienced for decades.
Japan, one of the most seismically-active places in the world, has stressed earthquake preparedness and regulations to make buildings quake-proof, but it has done less about potential flood disasters, said Okuma from Niigata University.
The torrential downpours have caused flash flooding and landslides across central and western parts of the country, prompting evacuation orders for more than two million people.
Nearly 2 million people were still subject to evacuation orders early this week, while tens of thousands of rescue workers braved the muddy waters to find people trapped in their homes.
Disasters set off by torrential rains have become more frequent in Japan, perhaps due to global warming, experts say.
Some people were already feeling unwell in the summer heat as they waited in line outside for a water supply truck at an evacuation center in Mihara, Hiroshima Prefecture, despite a portable air conditioning device cooling the spot.
Emergency rescue teams recover the body of a victim in the heavy rains, Monday, July 9, 2018, in Hiroshima, Japan.
"I'm anxious because I have no idea how long it will stay like this".
Japan Self-Defense Force soldiers rescue people from a flooded area in Mabi town in Kurashiki, Okayama Prefecture, on July 8.
"There have been requests for setting up air-conditioners due to rising temperatures above 30 degrees today, and at the same time we need to restore lifelines", Finance Minister Taro Aso told reporters after a cabinet meeting.
Several dozen Mihara residents ventured down from shelters on Sunday to inspect the damage to their homes in the Hongo district of the city, where many locals are rice farmers.
Elsewhere, work crews tried to clear multiple small landslides that coated roads, rendering them virtually impassable. Currently, it is known that 37 people have perished in Hiroshima, 20 have perished in Ehime, and a further 10 have been killed in Okayama.
"I'm really grateful to the rescuers", said Shigeyuki Asano, a 79-year-old patient who spent a night without electricity or water.
"We are doing our best".
In neighbouring Okayama prefecture, rescue workers flew in helicopters over areas that are still submerged and otherwise unreachable, looking for signs of life. "We are fully committed to life-saving rescue and evacuation", he said. Time is running out.
The meteorological agency downgraded its alerts for affected areas, but authorities warned that the risk of fresh landslides caused by rain-loosened earth remained high.
In Uwajima, Ehime Prefecture, a water purification plant was damaged by mudflows.
The devastation started when the typhoon system that brought the heavy rains first made landfall in Japan, but most of the deaths have been reported in the last two days.