[GRASS-user] The r.gmtg moduel for MODFLOW.

[Sören Gebbert]

Hi,

Hamish schrieb:
> Antonio Gennarini wrote:
>> I just downloaded the r.gmtg module from
>> http://www.valledemexico.ambitiouslemon.com/gwmodelling.html for
>> MODFLOW integration within GRASS. However, I don't seem to understand
>> how to compile this module. I seem to understand that I should be
>> using Gmake, however, Debian doesn't seem to have such a package ... 
>> What string should a give the compiler and what development packages
>> should be installed on my machine.
.....
> 
> 
> I see r.gmtg is for ground water flow modelling (MODFLOW). Maybe Soeren
> has some new and interesting module for GRASS 6.3 you could try?

There is a module called r.gwflow in CVS, but it is not that powerful
as MODFLOW. E.g: Leakage/Cauchy boundary conditions are missing.
Two scripts are included in the source directory which will help to understand
how to use this module.

If you want to try it, you need to check out the latest cvs version.
And there is currently no guarantee of correct calculation.

This is a sample script (included in the sources) computing steady state, unconfined
groundwater flow:

#!/bin/sh
# Shell script to verify r.gwflow calculation, this calculation is based on
# the example at page 167 of the following book:
#       author = "Kinzelbach, W. and Rausch, R.",
#       title = "Grundwassermodellierung",
#       publisher = "Gebr{\"u}der Borntraeger (Berlin, Stuttgart)",
#       year = "1995"
#
# set the region
g.region res=50 n=950 s=0 w=0 e=2000

r.mapcalc "phead= if(row() == 19, 5, 3)"
r.mapcalc "status=if((col() == 1 && row() == 13) ||\
                      (col() == 1 && row() == 14) ||\
                      (col() == 2 && row() == 13) ||\
                      (col() == 2 && row() == 14) ||\
                      (row() == 19), 2, 1)"

r.mapcalc "well=0.0"
r.mapcalc "hydcond=0.001"
r.mapcalc "reacharge=0.000000006"
r.mapcalc "top=20"
r.mapcalc "bottom=0"
r.mapcalc "syield=0.001"
r.mapcalc "null=0.0"

#compute a steady state groundwater flow
r.gwflow --o -s solver=cg top=top bottom=bottom phead=phead \
  status=status hc_x=hydcond hc_y=hydcond q=well s=syield \
  r=reacharge output=gwresult dt=864000000000 type=unconfined

# create contour lines
r.contour input=gwresult output=gwresult_contour step=0.2 --o
#create flow lines
r.flow elevin=gwresult flout=gwresult_flow skip=3 --o

#create the visualization
d.mon start=x0
d.mon select=x0
d.erase
d.rast gwresult
d.vect gwresult_flow render=l color=grey
d.vect gwresult_contour render=l color=black display=attr,shape attrcol=level lsize=16 lcolor=black
d.legend at=8,12,15,85 map=gwresult
d.barscale at=1,10
echo "Groundwater flow steady state" | d.text size=6 color=black



best regards
Soeren