Thierry

One solution
Perhaps you could design your model differently, for example try to change the bottom of layer 1 (and then your have to adapt layer 2, too probably) in order to have always the water leve in you first layer.  You have just to change the parameters when changing the lithology. 

I checked one of your previous message, I see that you put slice 2 (bottom of layer one) as fixed, I am not sure but for me it si not correct, because the layer 2 is then considered as confined and it seems to me that's not always true in your model?


have a nice day  :)

Dear Catarina,

If you send me a drawing with a schematic cross section of you terrain (no need to put names) I could try to understand better and help you more accuratly.  With position of piezometric levels for each layer in the hilly zone and the flat zone and an idea of the altitude.

Have a nice WE  :)

Dear Catarina



If you have dry cells in your layer 1, it is to say that your water level is under the bottom of the layer !

The result you obtain in this dry cells, is guided by your condition and is in your case (almost) at the bottom of the cells.

The question on unsaturated condition depend of what you understand with unsaturated condition ?

In the zone you have your dry cells, then your "true" water level is under the bottom of this layer then for you in layer 2 or layer 3.

your piezometry in layer 1 is available only for the saturated cells.  For a presentation of your results you have to take out the results in your dry cells.

One comment : perhaps your layer 3, in not always confined in all the area.

Your layer 3 could perhaps have confined and unconfined conditions it depends of what your are modelling?

But if you want to say that you see the piezometric level of layer 1 and layer 3 (you 2 aquifers), you have to take into account that in layer 1  your piezometric level could be a little bit higher due to the presence of semi-permeable, and If I suppose that layer is alimenting layer 3 etc...It depend of the situation you are modelling.


Hope this help you ! If you need more... :)


Have a nice day :D

Dear Catarina,

I suggest that you try to understand better your concept, you need to be clear with hydrological relationship between all your geological layers.  If I understand correctly : your layer 2 and perhaps layer 3 could be unconfined and confined depending hydrogeological circumstancies, and your layer 1 and layer 2 are not present on all you surface?

Without drawings or scheme it is sometime difficult to be sure... :-\

Your layer 1 covers all your surface, but where it desappears, I suppose that the tickness of this layer is very small (10-15cm) (you could check it, it depends of your model design), then there you but the caracteristics of underlaying geological layer. It is the same with layer 2.

I suggest that you put free&movable for slice at the top, fixed for the bottom slice and unspecified for the rest. In the problem definition menu, check the help and I think you could understand and solve your last question.  It depends if your cells in the layer 1 could be dry and this depend of the geometry of model etc...

I hope this help you, feel free to ask more details  :)

Best regards

Thank you for the answer Peter.  one precision, If I undertsand it correctly I need to do that all nodes are interconnected in the river with the BC (bold lines)?

regards

Hi,

I have a large river in the middle of my model (about 100 m large), I want to use 3rd kind boundary condition for this river, but I can only place (automaticaly) the boundary condition on the two edges of the river and I have node in the middle of the river area.

But I think I have to put this condition too inside the river area.  Then I don't know how  to do? ???

Have I to construct meshes using other lines inside the river area in order to align  nodes and to be able to put the 3rd kind boundary condition in all the river area???

If someone can help me, suggestions are welcome

Have a nice day

:D

Oups ! Finally I find the solution, it works with "join" and polygons for example and assigning the value for the polygon

Any other solution is always welcome

;)

Hi,


I need to introduce a Canal in my topography.  The problem is that I have the topographical information from digitized maps (not a DEM but just digitized topographical points and curves) and I have to introduce the bottom of a canal which is about 100 m large for 10 to 15 m deep (to have a design in U).  The bottom of the canal is composed by 3 fixed values and the edges of the canal are quite sharp.

The problem comes when I generate the top of the first layer because and evidently I have an interpolation between my topographical data and fixed data for the canal.

I have tried another think : I could obtain a topo for the first layer without the canal, and I thinked that after I could impose just the values for bottom of the canal in the canal area.  It seems that the only possility is impose the value node by node and not areally and the canal is about 20 km long (perhaps is it possible with polygons but I don't understand how).  ???

All idea or suggestion is welcome

PS: I used FEFLOW 5.2

Have I nice day ! :)

Thank you for your answer, it seems that is effectively the problem.

Hi,

I use feflow 5.2, I have trouble with generation of mesh.  I have one superelement and I add some lines (which are rivers) before generating the meshes.  When I start the mesh generation (for example with 4000 elements), Feflow close suddently without any error message.  I  use triangle Delaunay for mesh generation.

Is there a problem between the lines add-in which are close to the border (superelement)?  I have checked I thought  that was due to the fact that the line (rivers) were crossing the superelement, I cut the lines to have only lines inside the superelement.  It seems not enough.  The geometry of the lines don't seem to be complicated.


I appreciate any experience on this problems.

I wish a pleasant  day to everybody looking this message

Thierry