Message Boards

Back

Sediment Water Interaction

amr salama, modified 1 Year ago.

Sediment Water Interaction

Youngling Posts: 12 Join Date: 9/16/15 Recent Posts
Dear All,

I am interested in modeling the dynamics of nitrogen in an estuary in both ( water and sediment ) , my model is 2D model ( 1 layer ). i have read the manual of " Sediment-Water Interaction " , but still have some inquires.

First : in terms of sediment grid, is the sediment grid could be the same as water grid ? if yes, can i select the aggregated grid (.dwq) which was created for water column to be the sediment grid file, avoiding specifying zoning . also how to write the code manually in the input file (.inp) for this case.

Second : Is it mandatory to specify open boundaries for my sediment grid ?

Third : How to specify some sediment parameters ex: ( Temperature, pH, Porosity, Dissolved oxygen ) ?

Thanks in Advance.
Michelle Jeuken, modified 1 Year ago.

RE: Sediment Water Interaction

Jedi Knight Posts: 156 Join Date: 1/21/13 Recent Posts
Dear Amr Salama,

1) If you want to use the same aggregation as you used for the water column, you don't need further aggregation, and you can use the keyword NOAGGREGATION instead of specifying a grid definition. The include

2) you have to specify a lower sediment boundary names as this boundary is created automatically, but you can define them as closed when you don't have (consider) any burial/digging and seepage/welling in your model

3) When assuming fixed temperature, pH, etc, Just like normal parameters, or model them. When you use parameters, zoning can be handy, because is it makes it easier to define a temperature, pH profile for your sediment per layer. But you could also use the multiplier *. e.g. to make a temperature profile in a 2005 segment model with 3 sediment layers you can define the following in block 7:

PARAMETERS
Temperature
ALL
2005*25.0 ; watercolumn
2005*20.0 ; layer 1
2005*18.0 ; layer 2
2005*17.0 ; layer 3

Look at the D-WAQ Input file manual foor more information. I also have two examples. This one is available through open earth models:

https://svn.oss.deltares.nl/repos/openearthmodels/trunk/deltares/lake_veluwe_eco

And I've made a manual adoptation of the FTI tutorial example that runs BLOOM with layered sediment, and attached it here. To keep it small, I have left out the FLOW hydrodynamics, so you will have to rerun tut_fti_waq_agg_1y.mdf first.

To see how it works, do a textual compare of the three input files: tut_fti_waq_agg_1y.inp, tut_fti_waq_agg_bloom_1y.inp and tut_fti_waq_agg_bloom_laysed_1y.inp

good luck!

Michelle
amr salama, modified 1 Year ago.

RE: Sediment Water Interaction

Youngling Posts: 12 Join Date: 9/16/15 Recent Posts
Hi Michelle,

Thank you so much for reply, actually i am using S1/S2 approach (S12TraDetN) in order to calculate total resuspension flux from S1 also to calculate total burial flux from S1 to S2.
in the .lsp file there are three warnings related to these processes including

warning: output [VxRes0 ] not located
warning: output [VxBur0 ] not located
warning: output [VxSep0 ] not located

How can i overcome these warnings?

also, i need to add fixed layer thickness for the two layers.
Does this approach needs to specify sediment grid and boundaries ?

find attached my substance.sub file and my .lsp file
Michelle Jeuken, modified 1 Year ago.

RE: Sediment Water Interaction (Answer)

Jedi Knight Posts: 156 Join Date: 1/21/13 Recent Posts
Hi Amr

I'm afraid that when I look at your sub-file, you have mixed up in the two approaches to the sediment layers in Delwaq: S1/S2 approach and layered sediment/g-delwaq approach. The S12TraXX processes are for the S1/S2 approach, the TraSe2_XX processes are for the layered sediment. I think it is best to use the same approach for all the substances.

These variables you mention are defined at the exchanges between segments, not at the segments themselves. Currently it is not possible to output values at exchanges. You can ignore the warnings, or remove them from your sub file by switching them off as output from the TraSe2_XX processes in the PLCT.

Michelle
amr salama, modified 1 Year ago.

RE: Sediment Water Interaction

Youngling Posts: 12 Join Date: 9/16/15 Recent Posts
Hi Michelle,

Thank you again, the problem has been resolved by deselecting the process TraSe2_XX.