# Scenario Damage Assessment Calculator

Given a single event, this calculator is capable of computing the distribution of buildings in the different damage states.

## Blueprint information

- Status:
- Started

- Approver:
- None

- Priority:
- High

- Drafter:
- Vitor Silva

- Direction:
- Approved

- Assignee:
- None

- Definition:
- Approved

- Series goal:
- None

- Implementation:
- Started

- Milestone target:
- 0.6.0

- Started by
- John Tarter

- Completed by

### Related branches

### Related bugs

### Sprints

### Whiteboard

https:/

In order to make sure this calculator can be implemented, OpenQuake needs to support fragility functions. Fragility functions give the probability of exceeding certain limit states, for a set of intensity measure levels. These functions can also provide the percentage of building in each damage state, given an intensity measure level (e.g: for a PGA = 0.5, we'll have 30 % with no damage, 40% with moderate damage and 30% collapsed).

This calculator is similar to the deterministic event-based calculator, but instead of vulnerability functions, fragility functions are used. A finite rupture and an exposure model still needs to be provided. First, many ground motion fields are produced and for each field, the calculator computes the amount of buildings (or the building area) in each damage state, using the fragility functions.

The amount of buildings in each damage state can be aggregated, in order to come up with an aggregated building damage distribution. In addition, the spatial distribution of the percentage of collapsed buildings needs also to be computed (a.k.a. collapse map).