QGEP SWMM raingages export

[tproduit]

Currently one raingage per subcatchment is exported. Then, the user can assign the same rain to each raingages. However, the most common case would a single raingage for the entire study area.

In special cases, if the study area is very hilly and extended the user could then choose to add more raingages manually.

[sjib]

@DflGruBoe @kfischerar @urskaufmann What do you think about this. How many raingauges do you need in your projects?

[urskaufmann]

Till now the problem was, how many raingauges with good data are available in a study area. I have always defined the raindata in the hydraulic program, not in the vsa-dss database.

[tproduit]

Feedback from technical group:

• Literature shows that using several raingages provides more realistic results

• If raingages are inserted in QGEP (measuring_point):

  • the user can choose which rainage is exported
  • or the catchments can be linked to nearest raingage

Proposition:
We keep the current export (one raingage per catchment and document well how the raingages can be deleted and / linked to rain curve. We wait for other user feedbacks to decide if another strategy is better.

[ponceta]

@tproduit is the proposition added to the documentation?

@TriformMoritz do you agree with such strategy?

[tproduit]

Current export of rain gages works like this. It is documented in the PR

QGEP_SWMM creates one raingage for each subcatchment.

By default:

• Time serie: Each raingage is related to a default rain time serie called default_qgep_raingage_timeserie. The time serie must be created and the value Series Name updated accordingly.
• Other parameters have default SWMM values

See vw_swmm_raingages.sql for details.

[ponceta]

To be closed as soon as doc PR is merged !

[TriformMoritz]

I usually use only one rain for the whole area for one typical rain event (with a given retourn time amd a typical curve). So I would leave it as default.
Various raingages are for interesting if you use real measurements of an event in an area or long time series (LTS), I would do this normally in SWMM (like Urs said).

So my recommandation:

• Leave the default default_qgep_raingage_timeserie and link every catchment to the raingage (like it is done right now).
• Bonus 1: Make this "default rain" raingage visible in QGIS (so you can modify it inside QGIS for all catchments).
• Bonus 2: Leave the option to create and link other raingages and export them.

So if I understand Timothee, this is how it will work!

[cymed]

I agree with @TriformMoritz. This also treats the bug that two raingages are created for a catchment if it is connected to fresh- and wastewater