intro story Lake


Lakes and reservoirs are important resources for communities around the globe. They provide food, drinking and irrigation water and can also offer spots for recreation. Under certain conditions lakes can also represent a threat for local communities, such as flooding or limnic eruptions. The ecological state of shallow lakes may be hampered by suspended sediments due to wind driven currents and waves. In deep lakes, stratification can cause undesirable anoxic conditions in the deeper areas. Understanding these systems is crucial to enable a sound management of these water bodies.

Delft3D is the state-of-the-art modelling framework for hydrodynamics, water quality, ecology, waves and morphology.
Here, in this space, we share knowledge & experiences, and discuss issues related to modelling of lakes.






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


Message Boards

FLOW - No heat flux to air Warning

Fabrizzio Gonzales, modified 4 Years ago.

FLOW - No heat flux to air Warning

Youngling Posts: 1 Join Date: 3/1/16 Recent Posts

I'm producing a model on a lake with time and space varying temperature and wind velocities forcing.

I produced a first model over 1 year with constant initial conditions (cold start) and I'm using the results as a map file for the initial conditions of the year I want to model. Although the temperature of the map file is of around 4°C for the whole lake (the model starts at 01-01, in winter), I get a warning message during the simulation that resets my temperature to 0°C to the whole lake during the initial time steps of the simulation.

The warning message is:

*** WARNING Timestep 1: No heat flux to air; water temperature is 0 degrees in 2210 points.

I have these warning messages for the first days of the simulation (the time step is of 1 min). After a few days of simulation, the problem is gone and the lake starts to get warmer and after a few months the water temperature profiles are OK when compared with data measurements.

My time step is of 1 min and I'm using the ocean heat flux model.

Does anyone know what is the reason of this temperature reset, the warning messages and how could I solve it?

I have this error message only when using initial conditions from the map file. I didn't get these messages when I produced the cold start model.

Thank you for your help,

Alex Christensen, modified 4 Years ago.

RE: FLOW - No heat flux to air Warning

Youngling Posts: 7 Join Date: 12/19/13 Recent Posts

Were you able to figure out what was causing this warning? I am having the some problem.