User Forum of Software BASEMENT

Dominik

User

From: Bern

Registered: 2018-09-26

Posts: 19

Negative Inflow

Hello and good morning everyone,

I'm trying to generate a restart file and run in some problems with the hydrograph. Regarding the info-window the inflow of my two rivers are -0.000 at all times and some warnings are produced:

WARNING -> At the hydrograph boundary all edges are set inactive (not wetted), but
   the inflow is bigger than 0.0. Either the cells in the boundary cross
   section are too big or the inflow is too small to ensure that at least one
   element is wetted.

Does anyone know what that means? How can I set edges to active? The only thing I could think off was to set the "initial type" to something else then "dry". However, I want to set up a restart file from the scratch so I believe I need the "dry initial type"-part?

Another interesting thing is that the first time I tried this morning one of the two rivers worked (with exactly the same configurations). After restarting the simulation the second river got the same warnings.

PS: The inflows of my rivers are 15m3/s and 400m3/s which worked fine on previous simulations.

Last edited by Dominik (2019-05-01 08:33:13)

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Dominik Vogt
MSc Student Institute of Geography University of Berne

Stephan Kammerer

Developer

Registered: 2015-03-31

Posts: 67

Re: Negative Inflow

This problem can occur in case you assign relatively small inflow discharges to dry boundary edges with large elements and/or large minimum water depth. Here some possible solutions:

1. Reduce your minimum_water_depth to ensure that boundary elements are wetted

2. Use INITIAL type index_table to define an initial water depth for elements with certain MATID to avoid dry start conditions

3. If 1. or 2. don't solve the problem, you will need to increase your mesh resolution at your inflow boundaries