Wajima, Suzu Populations Down 30% from Pre-quake Level; Yomiuri Shimbun, LocationMind Conduct Joint Analysis Location Data   

The Yomiuri Shimbun

21:00 JST, February 22, 2025

The populations of Wajima and Suzu in Ishikawa Prefecture appear to have declined by at least 30% since the region was devastated by an earthquake on Jan. 1, 2024, and battered by torrential rain in September, a Yomiuri Shimbun investigation has revealed.

An analysis based on mobile phone location information indicated that the cities’ populations as of last month had plunged from levels recorded before the Noto Peninsula Earthquake.

Population data issued by the prefectural government based on residence certificates and other information suggested the populations had dipped by about 10% over the same period, but it seems that more people than estimated have actually evacuated from Wajima and Suzu and have yet to return.

The Yomiuri Shimbun jointly conducted the investigation into data related to people’s movement with LocationMind Inc., a Tokyo-based company established by researchers from the University of Tokyo. Major mobile carrier NTT Docomo, Inc. provided statistical data based on privacy-protected location information. Analyzing the data, the investigation considered people who stayed in Wajima and Suzu for a certain period to be residents and estimated how much the cities’ populations had changed since December 2023.

The analysis revealed that Wajima’s estimated population in January 2024 had tumbled 41% from the previous month. Wajima’s population slipped further in February 2024 to about 13,000 people — a drop of 45% from the pre-quake level. The city’s population rebounded somewhat after that but has plateaued since torrential rain in autumn caused flooding and other damage. As of January 2025, Wajima’s population was estimated to be about 16,000 people, down about 30% from the pre-quake level.

The proportion of residents who have not returned to Suzu is even higher. The city’s population in March 2024 was estimated to have declined 48% from the pre-quake level. The population has leveled off since autumn and was believed to be about 8,000 as of January 2025, a fall of 36% compared with the pre-quake level.

A clear difference was apparent between the proportions of elderly and working age residents who returned. Based on age data from mobile phone registrations, the rate of decrease in the estimated population aged under 65 was higher than that of those aged 65 and over in both cities as of January 2025.

Population figures for Wajima and Suzu announced by the prefectural government indicated both cities had lost about 10% of their populations between Jan. 1, 2024, and Jan. 1 this year, about one-third of the figures derived from the analysis of the location data. It is believed that many people have evacuated to other areas for lengthy periods without transferring their certificate of residence.

“People movement data is useful for grasping a more accurate picture of where people are residing,” said Ryosuke Shibasaki, chief technology officer at LocationMind and professor emeritus at the University of Tokyo.

Although demolition of quake-damaged homes has been progressing well, delays in the construction of public housing for disaster victims have been among factors behind the slow return of people to the region. It has been estimated that 1,000 to 1,400 housing units are needed in Wajima and about 700 units in Suzu, but it likely will be fiscal 2026 before many people can move into these homes.

“Reconstruction [of the cities] will fall further and further behind while people of the working generation haven’t return,” said Osaka Metropolitan University Associate Prof. Taku Sugano, an expert in reconstruction policies. “Thorough consideration needs to be given to securing employment that will support the livelihoods of young people and to improving the environment for raising children.”