User Forum of Software BASEMENT

Stefano Zazzara

User

Registered: 2016-04-10

Posts: 10

Rainfall

Hi everybody
I'm modeling a 2D case with a rainfall activity but I cannot find the best way to do that.
I'm using the following way assingning for each element an hydrogram of the rainfall.

SOURCE {
                EXTERNAL_SOURCE {
                    type        = source_discharge
                    element_ids = ( 1 )
                    file        = hydro1.txt
                }
                EXTERNAL_SOURCE {
                    type        = source_discharge
                    element_ids = ( 2 )
                    file        = hydro2.txt
                }
                EXTERNAL_SOURCE {
                    type        = source_discharge
                    element_ids = ( 3 )
                    file        = hydro3.txt

.....

But the problem is that I have 97000 element_ids and, obviously, the analysis has a big delay.
Can you help me???

René Kaufmann

User

Registered: 2016-01-28

Posts: 22

Re: Rainfall

Do you have for each element an other hydrogramm? Or is it the same?

Stefano Zazzara

User

Registered: 2016-04-10

Posts: 10

Re: Rainfall

I have a different hydrogramm depending of each cell's area.

René Kaufmann

User

Registered: 2016-01-28

Posts: 22

Re: Rainfall

I would like to help you as good as I can, therefore I need some more information.

What is the reason to create a separate hydrogramm to each cell? I think, you know the total amount of the rainfall in the whole catchment and then you split it up to each cell?!

And: Can you tell me a little bit more about your model, the catchment and your goal? Best would be a small draw with the catchment, the in- and outputs...

Thank you.

Stefano Zazzara

User

Registered: 2016-04-10

Posts: 10

Re: Rainfall

Exactly!!
Here you are the case that I have to study. ( https://www.dropbox.com/s/0fw82ibulrkum … 0.pdf?dl=0 )
As you can see I have a rainfall intensity in the whole catchment, so I've converted the mm/h constant value in m3/sec by multypling it for each cell's area.
I have done that because I didn't find a way to assign a costant hydrogramm throughout the area. So the restriction is that I have to put every cell's ID with its own hydrogramm depending by its own areas.
So, using this way, the simulation is too long in terms of time.
Have you find another way to simulate the rainfall?
Thank you

René Kaufmann

User

Registered: 2016-01-28

Posts: 22

Re: Rainfall

Thank you for your further informations.

For your DTM you will have a 2dm File. There you can extract every cell number. Do that and put all your element in this form:

EXTERNAL_SOURCE {
  type        = source_discharge
  element_ids = ( 1 2 3 4 ... 99999)
  file        = rainfall.txt
}

In the rainfall.txt put in the total discharge. Basement will automatically split the amount to the cells.

The External_Source term for inflow and outflow has to be before(!!) the rainfall.

Hope, this will help.

Stefano Zazzara

User

Registered: 2016-04-10

Posts: 10

Re: Rainfall

Thank you for your help!!
In this way it should be easier!! At least I don't have to do a batch file to write all the hydro%.txt
Regards!!!