intro story Coast / Estuary

Coast / Estuary

Coastal systems are among the most dynamic physical systems on earth and are subject to a large variety of forces. The morphodynamic changes occurring to coastlines worldwide are of great interest and importance. These changes occur as a result of the erosion of sediments, its subsequent transport as bed load or suspended load, and eventual deposition. 
 
Estuaries are partly enclosed water bodies that have an open connection to the coast. Estuaries generally have one or more branching channels, intertidal mudflats and/or salt marshes. Intertidal areas are of high ecological importance and trap sediments (sands, silts, clays and organic matter).
Within the Delft3D modelling package a large variation of coastal and estuarine physical and chemical processes can be simulated. These include waves, tidal propagation, wind- or wave-induced water level setup, flow induced by salinity or temperature gradients, sand and mud transport, water quality and changing bathymetry (morphology). Delft3D can also be used operationally e.g. storm, surge and algal bloom forecasting. 
 
On this discussion page you can post questions, research discussions or just share your experience about modelling coastal and/or estuarine systems with Delft3D FM. 
 

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Sub groups
D-Flow Flexible Mesh
DELWAQ
Cohesive sediments & muddy systems

 

 

Message Boards

cannot get algal grow at BLOOM

JR
Jeffrey Ren, modified 5 Years ago.

cannot get algal grow at BLOOM

Youngling Posts: 3 Join Date: 11/12/13 Recent Posts
I try to simulate Ulva growth with BLOOM model. After selecting processes and saved as substance file (see attached), the model runs ok, but Ulva never grow. Instead, the biomass of Ulva continuously decrease from start of simulation. Looking at output files, I also found that energy & mortality seem to be limited as output values of these ("limit e" & limit mor) are 1. I couldn't figure out what causes this.

Can anyone please check what I missing in setting "processes" or any where I did not get right.

If anyone wants to send message to my email box, here is my email address: j.ren@niwa.co.nz

Thanks in advance

Jeffrey

Attachments:

AM
Arjen Markus, modified 5 Years ago.

RE: cannot get algal grow at BLOOM

Jedi Knight Posts: 222 Join Date: 1/26/11 Recent Posts
Hello,

I consulted our BLOOM specialist and while he has little time at the moment to analyse the problem (note that Deltares will be closed during the coming week), he did have a few things that might be useful:
- Besides the substances files, we will need the .lst, .lsp and the resulting .his file. They contain information about what could be wrong in the input and what is happening in the calculation itself.
- If the calculation is 2D, the parameter SDMIX must be set to -0.25, but if it is 3D then the parameter should b set to -1.0 (see the bloom.spe file)

Regards,

Arjen
JR
Jeffrey Ren, modified 5 Years ago.

RE: cannot get algal grow at BLOOM

Youngling Posts: 3 Join Date: 11/12/13 Recent Posts
Thanks, Arjen
I've played with the model for many times, but the algae keep dying.
I attached *.lst & *.lsp files, but don't have any resulting *.his file.

Regards

Jeffrey

Attachments:

Michel Jeuken, modified 5 Years ago.

RE: cannot get algal grow at BLOOM

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

It looks like your model was started fine, but you didn't define any monitoring points! There for you don't have an his file (which only produces data for monitoring points). If you add monitoring points you can also see some of the results in the monitoring file (.mon), en maybe get an idea why the algae keep dying.

good luck,
Michel
JR
Jeffrey Ren, modified 5 Years ago.

RE: cannot get algal grow at BLOOM

Youngling Posts: 3 Join Date: 11/12/13 Recent Posts
Hi Michel
I selected a monitoring point and the model could generate a monitoring file (*.mon), but the algae still does not grow (keeping dying). I wonder if anyone has worked on BLOOM to simulate macroalgal (Ulva) biomass. I appreciate any suggestions on settings and substances files.

Jeffrey
Martin Schueder, modified 4 Years ago.

RE: cannot get algal grow at BLOOM

Padawan Posts: 52 Join Date: 10/8/13 Recent Posts
Hi Jeffrey,

I am still struggling to gain an understanding how just how Macrophytes such as Ulva are defined in WAQ, but I noticed that Ulva will show as "dying" when you have an observation point in a layer other than the bottom layer/segment. When I look at Ulva biomass in my bottom layer, it certainly grows even when observation points at the same grid indices but different layer show continual Ulva "death".

Perhaps you are not observing biomass at the bottom layer?

Hope this helps a little,

Martin