Clarification: Slope input format (m/m vs degrees) for Site Model in OpenQuake v3.23.3
Ridho Alfi Mubarok
Dear All,
I am currently working on a landslide modeling project using OpenQuake Engine v3.23.3.
I would like to clarify a detail regarding the slope input for the site model. The documentation mentions that the slope must be provided in m/m (rise/run) and will be internally converted to degrees for the landslide model.
However, upon reviewing the underlying Python code for the model (nowicki_jessee_2018), the parameter docstring specifies: :param slope: Topographic slope expressed in degrees. I also noticed that the function processes the slope directly (slope_coeff * slope) without any apparent internal conversion from m/m.
Could you please confirm: should I feed my raw site model data in m/m (as per the interface documentation), or must I supply it in degrees to match the function's parameters?
Thank you for your clarification.
Lana Todorovic
Thank you for your message.
Please note that this modification was introduced starting from version 3.24.0 (see the pull request: https://github.com/gem/oq-engine/pull/10589).
In the corresponding source code for this version, you can verify that the model includes the required conversion:
https://github.com/gem/oq-engine/blob/v3.24.0/openquake/sep/landslide/probability.py#L134
Kindly ensure that you are consulting the documentation matching your Engine version (in your case, 3.23.3). On the documentation page, you can select the appropriate version using the drop-down menu in the top-left corner. If you check version 3.23.3, you will see that slope is expected in degrees, not in m/m.
In summary:
- For Engine version 3.24.0 and later: provide slope in m/m
- For earlier versions: provide slope in degrees
I hope this clarifies the issue.
Best regards,
Lana