Creating Disaggregation Maps

[Arifan Syahbana]

To OpenQuake users

 Hi everyone, I hope all is well. We are currently conducting a disaggregation analysis to create a map (magnitude and distance) for a specific recurrent period. We've just found a way to disaggregate mentioned in the OpenQuake manual. This way results in a lot of CSV files (we export the calculated results to CSV), and we have a hard time because a lot of data is generated, and we have to choose the magnitude and distance with the highest PoE for each coordinate. Is there an easier way or tutorial to create a disaggregation map? Thanks for the help.

Regards

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Warmest Regards, 

Arifan Jaya Syahbana

[Merrick Taylor]

You need to process the data and then plot it. There are instructions both in the documentation (not the manual, but the Scientific reference) and on this google group (from earlier questions and responses from the developers on disgaggregation) on how to convert the output from OpenQuake to conventional "% contribution" per Bazzurro & Cornell (1999). Once you have done this you can generate a lookup table by magnitude and distance, to get the % contribution values into a format that can be plotted (e.g. google "lookup excel multiple criteria" for a guide on how to do this). I use Excel, and it can plot a 3D column graph of the disaggregation data fairly simply once it is in a suitable format for plotting. Once you have an Excel template set up, dropping in data from a different disaggregation calculation is easy. Others use python, Matlab or Grapher software. These latter tools may be required to plot columns comprising different epsilon values (as output from OpenSHA or USGS website for example), which is not possible in Excel. Once you have the table of disaggregation data you can readily observe the mode or calculate the mean magnitude and distance contributing to the hazard.

[Michele Simionato]

On Monday, August 30, 2021 at 10:52:43 PM UTC+2 Merrick Taylor wrote:

You need to process the data and then plot it. There are instructions both in the documentation (not the manual, but the Scientific reference) and on this google group (from earlier questions and responses from the developers on disgaggregation) on how to convert the output from OpenQuake to conventional "% contribution" per Bazzurro & Cornell (1999).

Actually since April it is possible to export the disaggregation PoEs in the conventional way (see https://github.com/gem/oq-engine/pull/6653). Next week we will release engine 3.12 and you will have this feature. A lot more could be done and should be done about disaggregation, but is a low priority for us since we do not have a paying project for that. However, the conditional spectrum is part of the METIS project and therefore it will be implemented soon.

    

                 Michele Simionato