[GRASSLIST:10007] Re: Filling with flood

[Ian MacMillan]

Hi all, an alternate way that I have made reservoirs is to use 
r.contour and make only the one contour line that I care about.  Then 
use v.digit to modify that line at the point that I want the dam.  
Convert that vector line to an area, and then back to a raster and 
voila, you have a surface that is at the height of your reservoir.  
This was a relatively fast method for me.

-Ian

On Jan 25, 2006, at 7:34 AM, Māris Nartišs wrote:

> Hi,
>
> How I did it:
>
> Creating dam:
> 1) With r.digit digitise map dam line; Assign correct height to it;
> 2) Grow it to 2 cells atleast to avoid any holes in dam;
> 3) With r.mapcalc add dam to DEM.
>
> Filling lake:
> 1) With r.digit create map with atleast one cell with any value below
> target water level (seed);
> 2) Feed in DEM, seed, target water level to r.lake.
>
> You'r done!
>
> Maris.
>
> Attached:
> sm_ice.jpg - screenshot form movie showing Smiltene palaeolake and
> possible ice margin, north Vidzeme, Latvia. Created with described
> steps, only instead of r.lake I used r.mapcalc with script (~20h to
> get such map on P4 3GHz compared to 1min on 800MGz PIII with r.lake).
>
> r_lake.zip - source code of new GRASS module. Use at Your own risk!
> Currently it lacks  nice blue color gradient for output maps. Any
> comments - welcome.
>
> 2006/1/25, RAVI KUMAR <ravivundavalli at yahoo.com>:
>> Hi
>> It will be nice if I can get a workedout example
>> where in a DEM is used to create a Dam and then flood it.
>>
>> Ravi
>>
>>
>> Hamish <hamish_nospam at yahoo.com> wrote:
>>
>>> I have a surface of watershed and wish to simulate a dam
>>> to see the area of inundation (flooding).
>>>
>>> Please suggest a simple method in GRASS6 to create a reservoir (Dam)
>>
>> d.rast.edit or r.digit+r.patch to make the dam, then use 
>> r.basins.fill?,
>> r.fill.dir? or the module recently (in the last month) announced on 
>> the
>> mailing list to fill depressions & r.mapcalc to compare/crop.
>>
>>
>>
>> Hamish
>>
>>
>>
>>
>>
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>>
> <sm_ice.jpg>
 >
 >
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