Bangladesh's First-Ever Sub-National Earthquake Risk Assessment Paves the Way for a More Resilient Future

Bangladesh faces a significant threat from earthquakes due to its location at the collision zone of active tectonic plates, with several fault lines traversing the country. Historically, Bangladesh experienced at least five major earthquakes between 1869 and 1930 that exceeded 7.0 on the Richter scale. Although Bangladesh has not witnessed a powerful earthquake in the past century, experts have signaled the statistical likelihood of such an event occurring within the next hundred years. 

In 2023 alone, Bangladesh saw a surge in earthquakes, recording six incidents above 5.0 on the Richter scale. While most earthquakes in recent times were relatively minor, they still pose significant risks due to the country's high population density and infrastructure challenges. Given the past earthquake history and the recent surge in tremors, it is critical to proactively prepare and enhance earthquake readiness measures.

Commencing the Sub-National Earthquake Risk Assessment in Bangladesh

In this context, the Ministry of Disaster Management and Relief (MoDMR) made a specific support request to the UN Office for Disaster Risk Reduction (UNDRR) and the UN Resident Coordinator’s Office (UNRCO) for a sub-national earthquake hazard and risk assessment in Bangladesh. The Global Earthquake Model (GEM) Foundation was chosen to take the lead on the technical work for this project.

The project developed a detailed, open sub-national earthquake risk model and evaluated seismic risk for Bangladesh at the zila and upazila levels. The risk model encompassed a probabilistic seismic hazard model, a building exposure model, and a seismic fragility and vulnerability model for Bangladesh's building stock. Additionally, it included critical scenarios for key cities based on the results of the probabilistic risk assessment in consultation with local stakeholders and experts. 

This process was overseen by a panel led by the MoDMR and included representatives from the Ministry of Housing and Public Works, Bangladesh Bureau of Statistics, Geological Survey of Bangladesh, Bangladesh University of Engineering and Technology, and the University of Dhaka.

Dissemination of Risk Assessment to Stakeholders

From 3-5 March 2024 in Dhaka, MoDMR, UNRCO, UNDRR, and GEM jointly organized a 4-day series of dissemination events to share the results of Bangladesh's first-ever sub-national earthquake risk assessment. 

The dissemination series presented the findings of the assessment, which covered districts and upazila administrative levels, and considered hazards, population exposure, critical infrastructure systems, vulnerabilities, potential economic losses, and abilities. 

Moreover, this assessment integrated the national population and housing census 2022, the most current data available in the country. Stakeholders appreciated the analyses and results highlighted, and welcomed the harmonization of the data with the needs and priorities of the Government of Bangladesh. The assessment will aid stakeholders in making evidence-based decisions for the prevention, preparedness, and response to humanitarian crises and disasters by considering systemic risks. 

The first two days of the dissemination series focused on introducing the pertinent government stakeholders to the project itself and its outcome and objectives. Government stakeholders took part in various sessions covering topics such as tectonic setting and earthquake scenarios; probabilistic seismic hazard assessment; probabilistic seismic hazard models; key findings of the 2022 national population and housing census; building and population exposure; social vulnerability modeling; and historical and hypothetical future earthquake scenarios in Bangladesh. 

After the model presentations and risk information, the third day was followed by a capacity development session for thirty-five students of geography, DRR, and geospatial studies from various universities in Bangladesh. GEM provided technical training on the OpenQuake engine, enabling students and professionals to conduct earthquake modeling and estimate damage, economic losses, and human casualties. The students were oriented and equipped with resources for future studies and research. 

On the last day of the series, the findings were shared with the humanitarian and donor communities to gather their input and advice on how they could use the data for their preparedness planning. 

The four-day dissemination series was crucial as it shared project findings with stakeholders, including government agencies, students, and humanitarian organizations, thereby promoting informed decision-making and effective planning. 

Leveraging Sub-National Earthquake Risk Assessment for a Resilient Bangladesh

The sub-national earthquake risk assessment in Bangladesh holds immense potential as a cornerstone for informed decision-making across various sectors, bolstering the nation's preparedness and resilience.

Cultivating public awareness: The assessment will serve as a vital tool to educate the public and policymakers about potential earthquake severity, highlighting probable magnitudes, tremor frequencies, and worst-case scenarios, and empowering individuals and authorities to take preparedness measures.

Empowerment of land-use planners: The planners will receive a comprehensive understanding of earthquake-prone areas, empowering them to strategically distribute resources, prioritize community safety, and potentially restrict development in high-risk zones. Similarly, spatial planners can use this knowledge to design community layouts, ensuring critical facilities and structures are situated in less susceptible areas.

Strengthening existing infrastructure: The assessment will enable prioritization of retrofitting efforts for crucial buildings like hospitals, emergency response centers, and government offices, ensuring their operational continuity and easing swift recovery post-earthquake.

Strategic infrastructure investment:  Investors can prioritize projects and distribute resources efficiently by pinpointing areas with lower seismic risks, contributing to the development of a more resilient infrastructure network.

Informed urban planning: Real estate development can be bolstered by incorporating earthquake considerations, informing the development of building codes emphasizing structural integrity, setting up designated emergency evacuation routes, and creating safe gathering spaces post-earthquake.

Sector-specific planning: The assessment's impact will extend beyond immediate measures, enhancing healthcare, education, and transportation planning, ensuring a more comprehensive and well-coordinated response to disaster events.

Earthquake preparedness extends beyond mitigation: This assessment will strengthen contingency planning by tailoring emergency response measures to find vulnerabilities, resulting in a swifter and more effective response, potentially saving lives. Search and rescue operations will become more efficient with insights from the assessment, directing valuable time and resources toward high-risk zones requiring immediate intervention.

Foster Improved Civil-Military Coordination: It will encourage a collaborative and effective response during emergencies by setting up a shared understanding of earthquake risks and using all available resources efficiently to minimize seismic event impact.

Way Forward

Government agencies and ministries are actively addressing earthquake risk and planning. However, a unified strategy is crucial, requiring collaboration from various stakeholders. This sub-national earthquake risk assessment serves as a critical stepping stone towards achieving this goal.

It presents an opportunity for the government, the UN, and international financial institutions to work together towards building sustainable and resilient cities and rural areas, minimizing human and infrastructural losses of an earthquake.

The final assessment reports will be published and delivered to MoDMR by May 2024. They will be ready for consideration in policy formulation and integration into learning curricula for disaster risk reduction , ensuring that the recommendations are incorporated into overall planning, preparedness, and Standard Operating Procedures .