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SEAWAT: Creating a HORIZONTAL FLOW BARRIER (HFB) file
M. vdW, modified 2 Years ago.
SEAWAT: Creating a HORIZONTAL FLOW BARRIER (HFB) file
Youngling Posts: 17 Join Date: 7/5/21 Recent Posts
Hello all,
In the iMOD manual, 11.11 Tutorial 10: .. HFB Package is stated:
“During the simulation iMOD translates the manually drawn sheet pile wall - … - to a continuous (kinked) line coinciding exactly with the lateral cell faces it intersects; when utilizing the HFB package the specified resistance is assigned to these cell faces. It is always a good idea to examine the result of such a translation, e.g. to check whether the discretization has resulted in a sheet pile wall that is fully continuous and thus behaving like a true barrier.”
What if the barrier is NOT fully continuous?
(This was the case when I created a .HFB7 file by applying ‘iMOD Simulation Manager > Model Type > Standard MODFLOW 2005’.)
Herewith the procedure:
Please note that a HFB7 file had another order of columns (IROW1 ICOL1 IROW2 ICOL2) instead of the SEAWAT required order: ICOL1 IROW1 ICOL2 IROW2.
Suggestion: Perhaps an idea to add this procedure to the manual?
Thanks in advance,
Martin
Example HFB file
# HFB6 File Generated by Modeller
0 0, 404
1 23 60 23 61 0.000000 1
1 23 61 24 61 0.000000 1
… 400 similar rows
1 39 32 39 33 0.000000 1
1 39 33 38 33 0.000000 1
In the iMOD manual, 11.11 Tutorial 10: .. HFB Package is stated:
“During the simulation iMOD translates the manually drawn sheet pile wall - … - to a continuous (kinked) line coinciding exactly with the lateral cell faces it intersects; when utilizing the HFB package the specified resistance is assigned to these cell faces. It is always a good idea to examine the result of such a translation, e.g. to check whether the discretization has resulted in a sheet pile wall that is fully continuous and thus behaving like a true barrier.”
What if the barrier is NOT fully continuous?
(This was the case when I created a .HFB7 file by applying ‘iMOD Simulation Manager > Model Type > Standard MODFLOW 2005’.)
Herewith the procedure:
- Draw the barrier in QGIS and save as shapefile
- Change to vertical-horizontal line segments (at the resolution of your model (…, 100, 50, 25, …); Snap to grid)
- Edit shapefile to change residual diagonal lines into vertical-horizontal line segments
- Snap to grid again (at the resolution of your model; 100, 50, 25, …)
- Create segments (at the chosen resolution; Split lines at maximum length, e.g. 100)
- Create points (v.to.points)
- Add coordinates to points
- Copy attribute table to Excel
- Transform coordinates to column and row numbers
- Create a graph to check barrier on continuity
- Create HFB6 file (see example below)
Please note that a HFB7 file had another order of columns (IROW1 ICOL1 IROW2 ICOL2) instead of the SEAWAT required order: ICOL1 IROW1 ICOL2 IROW2.
Suggestion: Perhaps an idea to add this procedure to the manual?
Thanks in advance,
Martin
Example HFB file
# HFB6 File Generated by Modeller
0 0, 404
1 23 60 23 61 0.000000 1
1 23 61 24 61 0.000000 1
… 400 similar rows
1 39 32 39 33 0.000000 1
1 39 33 38 33 0.000000 1