OpenQuake - Scenario Damage and Loss: Theoretical Background

Summary

This video, part of the USAID-supported Open Quake workshops, demonstrates how to perform damage and loss assessments for earthquake scenarios using the Open Quake Engine. It covers the theoretical framework of exposure and seismic vulnerability, essential for estimating potential losses from seismic events. The session includes practical exercises on preparing input files, conducting damage calculations, and visualizing results through graphical interfaces. Key concepts like risk, exposure modeling, and seismic fragility are explored, illustrating how these elements influence damage assessment. By understanding these principles, users can effectively analyze and mitigate seismic risk in various environments.

Takeaways

• 🌍 Understanding risk involves assessing the overlap between hazards, exposure, and vulnerability in seismic events.
• 🏢 Exposure is defined as the man-made environment at risk from earthquakes, including buildings, infrastructure, and cultural sites.
• 📏 Accurate geographical and numerical attributes are crucial for estimating damage and loss related to seismic hazards.
• 💰 Value and occupancy attributes help quantify potential losses by identifying the economic value and occupancy levels of exposed assets.
• 🏗️ Structural attributes characterize buildings based on their physical features, which influence their seismic vulnerability.
• 🛠️ Different approaches for modeling exposure can be applied depending on the scale of the study, from detailed surveys to national censuses.
• 📊 Seismic vulnerability encompasses both fragility (the likelihood of damage) and vulnerability (the likelihood of economic or human loss).
• 🔍 Fragility models establish the relationship between ground shaking intensity and potential damage states, aiding in risk assessments.
• 📈 Consequence models link damage states to economic losses, providing a comprehensive view of the impacts of seismic events.
• 🖥️ The OpenQuake engine allows for the integration of various models and visualization of risk scenarios, facilitating disaster preparedness and response.

Q & A

What is the primary focus of the workshop supported by USAID?

The workshop focuses on performing damage and loss assessments for earthquake scenarios using the OpenQuake engine.

How is seismic risk defined in the context of this workshop?

Seismic risk is defined as the probability of damage or loss from potential future earthquakes, which involves the interaction of a hazard source, exposure, and vulnerability.

What does 'exposure' refer to in seismic risk assessments?

Exposure refers to the man-made environment that is at risk from seismic events, including assets like buildings, schools, and infrastructure that can be damaged during earthquakes.

What are the essential attributes required for performing damage and loss assessments?

The essential attributes include geographical location, economic value, number of occupants, and structural characteristics of the exposed elements.

Why are geographical attributes important in assessing seismic risk?

Geographical attributes are crucial because they help determine the distance of elements from seismic sources, which affects the intensity of ground shaking and, consequently, potential damage.

What is the difference between fragility and vulnerability in seismic assessments?

Fragility represents the likelihood of an element suffering damage due to ground shaking, while vulnerability relates to the potential economic or human losses resulting from that damage.

How does the OpenQuake engine assist in managing seismic risk?

The OpenQuake engine allows users to perform risk analyses by modeling exposure at various scales, incorporating essential attributes for accurate damage and loss assessments.

What tool is mentioned for conducting field surveys during damage assessments?

The Inventory Data Capture (IDC) tool is mentioned as a resource for conducting detailed surveys during field inspections.

How can vulnerability models be developed according to the workshop?

Vulnerability models can be developed by establishing a relationship between ground shaking intensity and the percentage of loss, utilizing data from fragility models and other structural attributes.

What is the expected outcome of combining fragility and consequence models?

By combining fragility and consequence models, one can derive a comprehensive vulnerability function that estimates economic losses associated with different levels of damage.