This page describes how to use MESH to create a WATFLOOD "map" file from an existing MESH_drainage_database.r2c file.
Configuring SHDFILEFLAG
This process requires a drainage database and to activate the option via SHDFILEFLAG in MESH_input_run_options.ini.
If the setup already has SHDFILEFLAG with option 1, the "to_map" option can be appended to the flag:
##### Control Flags #####
----#
1 # Number of control flags
SHDFILEFLAG 1 to_map
If the setup already has SHDFILEFLAG with option "r2c", the "to_map" option can be appended to the flag:
##### Control Flags #####
----#
1 # Number of control flags
SHDFILEFLAG r2c to_map
Running the Model
An existing MESH setup can be run as-is. The model will create a new file named "MESH_basin.map".
If no existing MESH setup exists, a MESH_input_run_options.ini file can be created with only the following options (a sample file is attached for reference):
MESH run options input file
##### Control Flags #####
----#
1 # Number of control flags
SHDFILEFLAG r2c to_map
##### Output Grid selection #####
----#
0 # Number of output grid points (5 points maximum)
---------#
1 #1 Grid number
1 #2 Land class
. #3 Output directory
##### Output Directory #####
---------#
. # Output Directory for total-basin files
##### Simulation Run Times #####
---#---#---#---#
0 0 0 0 # Start year, day, hour, minute
0 0 0 0 # Stop year, day, hour, minute
The model can then be run. The model will exit when it fails to read other input files, but before existing will have created a new file named "MESH_basin.map".
Limitations
Some variables cannot be derived from the attributes of MESH_drainage_database.r2c alone. The following table lists the "map" file attributes created by this process.
| WATFLOOD "map" file attribute | Restored? | Detail | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Channel Elevation (ELV) |  - Yes | From the native "Elev" attribute | ||||||||||||||||||
Drainage Area (FRAC) | - Yes | Calculated as the "
`"FRAC" = "GridArea"//"AL"//"AL"`
| ||||||||||||||||||
Drainage direction (S) | - Yes | Derived from the " do y = 1, yCount
do x = 1, xCount
if (RNKGRD(y, x) .gt. 0) then
if (NEXT(RNKGRD(y, x)) .gt. 0) then
grid(y, x) = -1
if (y .gt. 1) then
if (x .gt. 1) then
if (RNKGRD(y - 1, x - 1) .eq. NEXT(RNKGRD(y, x))) DDIR(y, x) = 5
end if
if (x .lt. shd%xCount) then
if (RNKGRD(y - 1, x + 1) .eq. NEXT(RNKGRD(y, x))) DDIR(y, x) = 3
end if
if (RNKGRD(y - 1, x) .eq. NEXT(RNKGRD(y, x))) DDIR(y, x) = 4
end if
if (y .lt. yCount) then
if (x .gt. 1) then
if (RNKGRD(y + 1, x - 1) .eq. NEXT(RNKGRD(y, x))) DDIR(y, x) = 7
end if
if (x .lt. xCount) then
if (RNKGRD(y + 1, x + 1) .eq. NEXT(RNKGRD(y, x))) DDIR(y, x) = 1
end if
if (RNKGRD(y + 1, x) .eq. NEXT(RNKGRD(y, x))) DDIR(y, x) = 8
end if
if (x .gt. 1) then
if (RNKGRD(y, x - 1) .eq. NEXT(RNKGRD(y, x))) DDIR(y, x) = 6
end if
if (x .lt. xCount) then
if (RNKGRD(y, x + 1) .eq. NEXT(RNKGRD(y, x))) DDIR(y, x) = 2
end if
end if
end if
end do
end do
The WATFLOOD "map" file does not use standard D8 drainage directions, instead using:
| ||||||||||||||||||
River Class (IBN) | - Yes | From the native "IAK" attribute | ||||||||||||||||||
Contour Density (IROUGH) |  - No | Not calculated, but speculated to be the following equation based using the "
`"IROUGH" = ("IntSlope"*"AL")/("ContourInterval" - 0.0001)`
| ||||||||||||||||||
Channel Density (ICHNL) | - Yes | From the native "Chnl" attribute | ||||||||||||||||||
Reach Number (IREACH) | - Yes | From the native "Reach" attribute | ||||||||||||||||||
| GRU/Land cover fractions | - Yes | From the native "
`"PERC" = "ACLASS"*100.0`
|
Considerations
This process will decrease the number of cells in the domain "TotalNumOfGrids" when converting from a MESH_drainage_database.r2c file where an outlet is not properly defined (e.g., when "numGridsInBasin" is equal to "TotalNumOfGrids").
In this case, the last cell in the domain likely drains into itself, and thus a representative drainage direction cannot be derived from "Rank" and "Next" alone.
Related articles
-
SHDFILEFLAG — The SHDFILEFLAG control flag specifies the basin information file format.
-
How to define river classes (IAK) using drainage area (DA) and optional GRU filtering — This page describes how to create river classes in MESH_drainage_database.r2c using drainage area (DA) and optional GRU filtering.
-
How to create WATFLOOD "map" file attributes from MESH_drainage_database.r2c — This page describes how to use MESH to create a WATFLOOD "map" file from an existing MESH_drainage_database.r2c file.
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