dvb

Some questions:
- How to interpret heads calculated above water table level in Feflow/Phreatic mode ? What is the best way to plot the water table contours ?
- How is simulated the unsaturated zone above the water table in Phreatic mode, and how is the in/out flow transmit from the ground to the water table ?
Thanks !
Didier

Probably something due to the fact that your using free&moveable, cf help file:
"if the entire first stratigraphic layer is dry, the first computational layer will be in the second stratigraphic layer, inheriting all material properties of this"
Is it your case ?

It seems that both GRASS and R packages may offer solutions to perform 3D kriging, but nothing obvious here.

Sure. The constrained flux will only help you to justify or correct your DE parameters. Once you reach a satisfaction, I believe you can switch it back to the estimated head, and simulated scenarios which affect your flux.
Cheers !
did

Maybe try a specific flux BC at the outlet. If your DE has more flow than your BC, you will see water mounding around your outlet, because the model doesn't expediate all the flow that you want to. If your DE has less flow than your BC, you will see the inverse (the model has to extract more water than the flow from the DE, thus creating a drawdown cone around your outlet).

Since the date I wrote my post I can give some elements of reply:
- they aren't solutions to remove flow from DE except by linking them with a BC
- you may play with the arbitrary element to simulate plain pipes that are not directly linked to the aquifer except at the entrance and outlet of the pipe
- you should use a seepage face at the outlet of the pipe if you know the elevation of the outlet. Otherwise you can consider a flux, equal to your flow rate/pipe or gallery area, and watch for the quality of your piezometric contours around your outlet. You may see mounding or depressurisation if your flux BC is too low or high respectively.
- to use the 3rd type BC you have to assign In and Out flow rate in the DE parameter panels (I think).

It's just guess .... feel free to share your own ideas :) !
Didier

With pleasure :) je t'envoie un MP

Your model seems to face very unstable conditions, which may be due to many different reasons. A proper way of resolving those issues is to locate them by placing several control points (piezometers), and check if they are stable, and also to check your water balance who should be closed to be null.
Before that, be sure that your initial heads are correct (no bullets, no extreme floodings and dewatering, steep gradients, etc etc etc).

Also to start your model in steady state, you don't have to export and reimport your heads. Just save your transient run under a new name and switch, in the problem class, to steady state instead of transient. A window will be prompted asking you from which time should the model take the conditions as steady.

Good luck !

This year I decided to start using the open source solution QGis instead of ArcGIS (ArcMap), in such a way to reduce my financial dependance of expensive softwares. Actually QGIS is just great and even if it doesn't seems to do everything that does ArcGIS, it does things that ArcGIS doesn't do or doesn't do easily. Here are some examples of useful that does QGis:
- I used to transform my iso-lines into points and use those points to interpolate my ascii grids with surfer. With QGIS you can use directly the lines or lines+points. They are several output formats available. Triangulation method only, which is nonetheless sufficient when a lot of data are available.
- split a X-Y-SLICE-F shapefile into as many shapefiles that you have SLICES, in just a mouse click
- perform the usual querry and calculations on a shapefile
- perform SURFER type of Grid maths (like slice1 elevation - slice 2 elevation, etc)
- transform a grid into an imprehensive choice of formats
- very convenient way of georeferencing a raster
- easy to browse catalog of coordinate systems
- easy to browse catalog of WMS coverages
- motivated community of users
- lot of extensions available for free, lots of updates and new extensions frequently coming out
- exciting development to come, like 3D viewers and more incorporation of GRASS tools

It's easy to learn when you are confortable with GIS technologies. So don't hesitate !

Question regarding discrete elements. We are simulating a network of old mine galleries, that are draining the surrounding reservoir. To linke all together those galleries which are at different levels/slices, we use vertical elements. Upgradient the galleries outlet there is a flow that is consistent with the reality, however we can't find a way to remove that flow from the model, either with the source/sink editor of the DE parameters panel, or by linking the DE with one of the proposed BC. We would like to avoid using an IFM module if possible ...

Thanks, Didier