Practical Guide to Social Vulnerability Mapping During Disasters — Lessons from the Noto Peninsula Earthquake

Introduction

The Noto Peninsula earthquake of January 2024 once again highlighted the social dimensions of disasters. With a maximum intensity of 7 on the Japanese scale and over 470 deaths (including 228 direct deaths and disaster-related deaths, as of March 2025), the damage concentrated in depopulated areas with aging rates exceeding 50%, exposing the vulnerability of evacuation support systems for people requiring special assistance.

While disasters are "natural phenomena," the damage they cause is a "social phenomenon." Even with the same seismic intensity, the impact varies dramatically depending on who is affected, where they are, and under what social conditions they experience the disaster. A "social vulnerability" perspective based on this recognition is essential for effective disaster prevention.

This guide explains methods for social vulnerability mapping that NPOs and community organizations can implement, incorporating lessons from the Noto Peninsula earthquake.

What is Social Vulnerability?

Understanding Structure Through a Five-Layer Model

Social vulnerability is not determined by a single factor but is formed through the overlap of multiple layers. We organize this using the following five-layer model:

The important point is that these layers mutually reinforce each other. A situation where an elderly person living alone with physical vulnerability (Layer 1) and social isolation (Layer 3) lives in housing that lacks seismic reinforcement due to economic reasons (Layer 4) and has no individual evacuation plan (Layer 5)—in the Noto Peninsula earthquake, this compound vulnerability directly resulted in damage.

Structure of Disaster-Related Deaths

Disaster-related deaths from the Noto Peninsula earthquake continued to increase for months after the disaster. Most were elderly people over 75, with the main causes being deteriorating living conditions in evacuation centers, worsening of chronic conditions, and hypothermia. Vulnerability countermeasures that include prevention of not only direct deaths but also disaster-related deaths are required.

Methods for Creating Maps of People Requiring Special Assistance

Step 1: Identifying Target Individuals and Handling Personal Information

Based on Article 49-11 of the Disaster Countermeasures Basic Act, municipalities are required to create "lists of people requiring evacuation assistance." However, while the preparation rate of such lists reaches approximately 98% nationwide, the formulation rate of "individual evacuation plans" based on these lists remains at only about 20% as of 2024.

For NPOs to access list information, concluding an agreement with the municipality is a prerequisite. While ensuring consistency with personal information protection ordinances, proceed with the following steps:

1. Consultation with municipal disaster prevention departments: Confirming ordinances regarding external provision of lists
2. Concluding agreements: Clearly stating the purpose of personal information use, management systems, and disposal methods
3. Obtaining consent from people requiring assistance: Information sharing based on personal consent is the principle (with exceptions during disasters where consent is not required)

Step 2: Overlaying with Geographic Information

By overlaying the location information of people requiring special assistance with the following geographic data, we can visualize the spatial concentration of risks.

Even without specialized knowledge of GIS (Geographic Information Systems), simple mapping using QGIS (free) or Google Earth is possible. The important thing is not to create a perfect map, but to gain a rough understanding of "where risks are concentrated."

Step 3: Vulnerability Scoring

Introduce a scoring method to quantify the vulnerability of each area.

Classify each area as "high risk," "medium risk," or "low risk" based on total scores, and determine resource allocation priorities.

Evacuation Center Management and Inclusion

Current Status and Challenges of Welfare Evacuation Centers

Welfare evacuation centers are evacuation centers with special considerations for people requiring assistance. In the Noto Peninsula earthquake, the opening rate of designated welfare evacuation centers fell below 50%, and even after opening, shortage of specialized staff became a serious problem.

The roles required of NPOs can be organized into the following three points:

• Promoting advance agreements: Advocating for conclusion of welfare evacuation center agreements between social welfare facilities and municipalities, ensuring effectiveness
• Securing operational personnel: Building networks of specialists such as certified care workers and nurses during normal times
• Conducting drills: Implementing welfare evacuation center opening drills at least once a year with participation of the people requiring assistance themselves

Evacuation Center Design with Consideration for Diversity

Evacuation center management that reflects diversity in gender, disability types, and cultural backgrounds directly relates to preventing disaster-related deaths. We present a specific checklist:

• Partitions and private spaces: Ensuring privacy for women and disabled individuals
• Multilingual signage: Minimum of four languages including English, Chinese, Vietnamese, and Portuguese
• Allergy-compatible food: Religious and medical considerations in food distribution
• Nursing and diaper changing rooms: Consideration for households with infants
• Barrier-free routes: Ensuring access for wheelchair and walker users

The Concept of Capacity to Receive Aid

Building "The Ability to Receive Help"

Capacity to receive aid refers to a disaster area's ability to effectively accept external assistance. This concept was proposed in the Cabinet Office's "Guidebook for Improving Capacity to Receive Aid" (2019), and insufficient capacity to receive aid was reported to have caused delays in assistance in multiple instances during the Noto Peninsula earthquake.

The components of capacity to receive aid consist of the following three elements:

1. Information transmission capacity: The ability to accurately communicate what is lacking, where, and to what extent. Minimizing information gaps immediately after disasters
2. Coordination capacity: The presence of aid reception coordinators who match and deploy external support organizations. In Noto, some areas required over a week to establish disaster volunteer centers
3. Reception infrastructure: Advance securing of collection points for relief supplies, accommodation for volunteers, and activity bases

What NPOs Can Do During Normal Times

• Supporting formulation of aid reception plans: Advocating for incorporation of "aid reception plans" into municipal regional disaster prevention plans
• Collaboration with disaster intermediate support organizations: Building relationships during normal times with national networks such as JVOAD
• Developing IT infrastructure: Advance construction of systems to match support needs with support resources during disasters

Conclusion

Disaster damage manifests in ways that amplify existing social inequalities. The more aging and depopulation advance in an area, the higher its disaster vulnerability becomes, creating a vicious cycle where support becomes harder to deliver.

Social vulnerability mapping is a foundational technology for visualizing this structure and delivering limited resources to where they are most needed. There is no need to wait for perfect data. We can grasp "where risks are concentrated" with currently available information, and from there proceed to formulate individual evacuation plans, develop welfare evacuation centers, and improve capacity to receive aid. The Noto Peninsula earthquake has once again thrust upon us the urgency of taking that first step.

References

令和6年能登半島地震を踏まえた災害対応検討ワーキンググループ報告書

内閣府（防災担当）. 内閣府

Read source

避難行動要支援者の避難行動支援に関する取組指針

内閣府（防災担当）. 内閣府

Read source

At Risk: Natural Hazards, People's Vulnerability and Disasters (3rd Edition)

Wisner, B., Blaikie, P., Cannon, T. & Davis, I.. Routledge

Read source

受援力向上ガイドブック

内閣府（防災担当）. 内閣府

Read source