User Forum of Software BASEMENT

Elke

User

Registered: 2024-08-23

Posts: 1

Modelling rainfall

Hello everyone,

has anyone of you experience in simulating a rain event with BASEMENT v4?

I would like to simulate a rain event over the entire model, but unfortunately it is not yet working as expected:

At first I created a mesh as I usually do when simulating a river channel. I defined region points and strings (in- and outflow) in the mesh and then parameterised them in my setup file. To simplify the model, I only considered one region in the entire model "Settlement". I implemented the rain using "Source" because it rains over the entire model (over the "Settlement" region) and defined the "Source" as follows:

SOURCE
   name = "rainfall"
   region_name = "Settlement"
   type = "total"
   sink = "exact"
   data = "200"

I have definied the inflow and outflow using the standard boundaries as uniform_in and uniform_out.
However, the specification of a flow rate is necessary here, which is not actually necessary for the simulation of a rainfall?

But when I completely remove the in- and/or outflow, I get the following error message:
-> ERROR in kernel_HYDRAULICS_Source... LIQUID MASS not conserved
-> ... unfortunately BASEMENT is killed!

Does anyone know how I can avoid this porblem or is my strategy wrong?

Greetings!

Matthias Bürgler

Developer

From: Zürich

Registered: 2019-04-04

Posts: 175

Re: Modelling rainfall

Hi Elke

If you only want to impose rainfall via a source term, then the SOURCE block would be the way to go. The uniform_in and uniform_out standard boundary conditions are typically used to impose in- and outflow of rivers.

The 'type' specifies the unit of the value in 'data' or the value time series in 'file'. The unit of 'type' = 'total' is m3/s, whereas 'type' = 'distributed' results in units of mm/h. So in your case you add 200 m3/s to the Settlement region. But without further information I cannot say why you get en error when you remove the in- and outflow boundaries.

Best regards,
Matthias