open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,all. I am using code of mascaret v8p5r0 to simulate hydrodynamic process. However, I got error that *** cross section is dry. I am wondering what's the reason of the error and how to solve it.
Thanks.

Hello,
To be able to help you, we'll probably need more information. However, this error often occurs when the time step is too large compared to the discharge. The variation between upstream and downstream flow generates dry meshes. Try reducing the time step.

Thanks for your kind reply. Because the spacing of cross-section is large (over 5 kilometers), I used the 5th mesh method to run the model and got the right results of flow. However, I found that the 5th mesh method (5</methodeMaillage) could not be used for the Courlis module coupled with sediment. From the examples given by Courlis, only the first mesh method (1</methodeMaillage) was used. Is there any way to interpolate cross-sections in the Courlis module?
<methodeMaillage>5</methodeMaillage>
<planim>
<nbPas>100</nbPas>
<nbZones>1</nbZones>
The < valeursPas > 1.0 < / valeursPas >
<num1erProf>1</num1erProf>
<numDerProf>34</numDerProf>
</planim>

Cannot tell what's wrong with Courlis.
But, key "parametresPlanimetrageMaillage/methodeMaillage" relates to longitudinal discretization.
Setting "1" means you are using profile of geometry file(no further discretization).
Setting "5" means you are using so-called "series-profile" method, in which profile of geometry file is retained while disretized nodes are set between every two profiles using value of key "parametresPlanimetrageMaillage/maillage/maillageClavier/pasEspacePlage".
This key is not related to vertical discretization inside "parametresPlanimetrageMaillage/planim".