Event-Based PSHA Outputs

The Event Based PSHA calculator computes and stores stochastic event sets and the corresponding ground motion fields. This calculator can also produce hazard curves and hazard maps, similar to the Classical PSHA calculator. The inset below shows an example of the list of results provided by the OpenQuake engine at the end of an event-based PSHA calculation:

user@ubuntu:~$ oq engine --lo <calc_id>
id | name
10 | Ground Motion Fields
11 | Hazard Curves
12 | Hazard Maps
13 | Realizations
14 | Earthquake Ruptures
15 | Events
16 | Uniform Hazard Spectra

Exporting the outputs from the ruptures will produce a CSV file with the following columns:

1. rup_id: incremental number identifying the rupture

2. multiplicity: how many times the rupture occurs in the effective investigation time

3. mag: float specifying the magnitude of the rupture

4. centroid_lon: longitude of the centroid of the rupture

5. centroid_lat: latitude of the centroid of the rupture

6. centroid_depth: depth (in km) of the centroid of the rupture

7. trt: string specifying the tectonic region type

8. strike: strike angle of the rupture surface

9. dip: dip angle of the rupture surface

10. rake: rake angle of the rupture surface

The outputs from the Ground Motion Fields can be exported in the csv format. Exporting the outputs from the Ground Motion Fields in the csv format results in two csv files illustrated in the example files in this document. The sites csv file provides the association between the site ids in the Ground Motion Fields csv file with their latitude and longitude coordinates.

Example of a ground motion fields csv output file for an event based hazard calculation

rlz_id	site_id	event_id	gmv_PGA	gmv_SA(0.3)	gmv_SA(1.0)
0	0	48	0.0089	0.0686	0.0065
0	0	54	0.0219	0.0325	0.0164
…	…	…	…	…	…
0	6	75	0.0246	0.0244	0.0036
1	0	76	0.0189	0.0327	0.0094
1	0	77	0.0286	0.0683	0.0471
…	…	…	…	…	…
…	…	…	…	…	…
7	6	1754	0.3182	1.2973	0.6127
7	6	1755	0.2219	0.6200	0.5069

The Events output produces a csv file with fields event_id, rup_id and rlz_id. The event_id is a 32 bit integer that identifies uniquely the event; the rup_id is a 64 bit integer that identifies uniquely the rupture; the rlz_id is a 16 bit integer that identifies uniquely the realization. The association between the event_id and the rup_id is stored inside the Events output.

The Realizations output produces a csv file listing the source model and the combination of ground shaking intensity models for each path sampled from the logic tree. An example of such a file is shown below in the table below.

Example of a realizations file

ordinal	branch_path	weight
0	b1~b11_b21	0.1125
1	b1~b11_b22	0.075
2	b1~b12_b21	0.0375
3	b1~b12_b22	0.025
4	b2~b11_b21	0.3375
5	b2~b11_b22	0.225
6	b2~b12_b21	0.1125
7	b2~b12_b22	0.075