intro story DELWAQ


DELWAQ is the engine of the D-Water Quality and D-Ecology programmes of the Delft3D suite. It is based on a rich library from which relevant substances and processes can be selected to quickly put water and sediment quality models together.

The processes library covers many aspects of water quality and ecology, from basic tracers, dissolved oxygen, nutrients, organic matter, inorganic suspended matter, heavy metals, bacteria and organic micro-pollutants, to complex algae and macrophyte dynamics. High performance solvers enable the simulation of long periods, often required to capture the full cycles of the processes being modelled.

The finite volume approach underlying DELWAQ allows it to be coupled to both the structured grid hydrodynamics of the current Delft3D-FLOW engine and the upcoming D-Flow Flexible Mesh engine (1D-2D-3D) of the Delft3D Flexible Mesh Suite (or even other models such as TELEMAC).

'DELWAQ in open source' is our invitation to all leading experts to collaborate in further development and research in the field of water quality, ecology and morphology using Delft3D. Feel free to post your DELWAQ related questions or comments in this dedicated forum space. If you are new to DELWAQ, the tutorial (in the user manual) is a good place to start. A list of DELWAQ related publications is available here.




Sub groups
D-Flow Flexible Mesh

Cohesive sediments & muddy systems


Message Boards

RadSurf file in BLOOM

Amelia Araujo, modified 2 Years ago.

RadSurf file in BLOOM

Youngling Posts: 13 Join Date: 7/7/15 Recent Posts


I want to impose the RadSurf in my BLOOM simulation as a time series. Following the advice below, I have prepared a daily averaged file:


However, reading the manual, I still have doubts about what I should provide in this file. In page 163 of the D-Water_Quality_Processes_Technical_Reference_Manual , it says:

“The light intensity at the water surface RadSurf is the total visible light intensity (solar radiation) or the photosynthetic active light intensity corrected for reflection”.

The solar irradiance contains wavelengths other than the visible spectrum (NIR, UV), so I would say that according to this sentence I would need to correct my net short wave Radiation data to get the energy in the range 400-700nm, which is the visible and also approx. the PAR.

But, if I read the last sentence of directives for use in the same page of the manual: “Phytoplankton module BLOOM uses the daily average radiation. In its standard setting it uses total visible light and carries out corrections for both reflection and photo-synthetic fraction”

I understand that the correction for PAR is done automatically in the code and that I just need to provide the net shortwave radiation. Am I right?? This is a bit confusing for me.

Thanks for your clarifications.