[GRASS-user] Re: highest and lowest point in catchment

[Richard Chirgwin]

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> Today's Topics:
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>    1. highest and lowest point in catchment (Dr. Manuel Seeger)
>    2. SHELL Variable problem: Workaround (Peter L?we)
>    3. Re: SHELL variable not set (Martin Wegmann)
>    4. Re: SHELL variable not set (Glynn Clements)
>    5. Re: SHELL variable not set (Hamish)
>    6. Re: SHELL variable not set (Markus Neteler)
>    7. Re: Building wxgrass vdigit (Martin Landa)
>    8. segment_format error with r.watershed (Wes Kent)
>    9. union features of vector (Alfredo Alessandrini)
>   10. Re: Snap across layers (Martin Landa)
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> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 29 Jan 2008 10:01:20 +0100
> From: "Dr. Manuel Seeger" <seeger at uni-trier.de>
> Subject: [GRASS-user] highest and lowest point in catchment
> To: GRASSLIST <grass-user at lists.osgeo.org>
> Message-ID: <479EEB60.6050606 at uni-trier.de>
> Content-Type: text/plain; charset=ISO-8859-15; format=flowed
>
> Hello all,
> I hope the questions does not seem too simple, but I have now no real 
> good idea how to solve this simple problem:
>
> I need to find the highest and the lowest point within catchments WITH 
> their coordinates (and to get the information about altitude and 
> coordinates, of course)
>
> thanks for hints!
>
> manuel
>
>   
Manuel - hope I'm not being silly here, but I'd consider just using an 
SQL select directly to the data store.

Select max( <altitude column> ), <latitude column>, <longitude column>, 
<any other column you want> from <table> where <boundary conditions of 
catchment>
Select min( <altitude column> ), <latitude column>, <longitude column> 
<any other column you want> from <table> <boundary conditions of catchment>

If you have to, you could extract only the catchment to a separate 
vector, so that you don't need to fool around with complex boundary 
conditions.

But I'm sure that a genuine Grass expert will have a simpler solution 
than this ...

Cheers,
Richard