[GRASS-dev] r.sim.water buffer overflow

[Helena Mitasova]

I am guessing it is the latlong but I would have to try it out,

Helena Mitasova
Associate Professor
Department of Marine, Earth and Atmospheric Sciences
North Carolina State University
Raleigh, NC 27695
hmitaso at unity.ncsu.edu



On Aug 18, 2010, at 11:03 AM, Markus Neteler wrote:

> On Wed, Aug 18, 2010 at 8:31 AM, Hanlie Pretorius
> <hanlie.pretorius at gmail.com> wrote:
>> Hi,
>> 
>> I'm posting here because I had no reaction on the users email list.
> 
> 
> (Hint: if you post an example for a sampe data set like Spearfish or
> North Carolina, then it is way easier to reproduce for us...)
> 
>> I'm using GRASS64 RC6 on Linux 10.04 (64-bit) and I'm trying to run
>> r.sim.water on a catchment about 5000 km2 in size.
>> 
>> I started with a very fine resolution in my region (00:00:00.18) and
>> got the following:
>> -----
>> GRASS 6.4.0RC6 (world_wgs84):~ > r.sim.water
>> elevin=lieb_dem_25m_clipped dxin=lieb_dem_25m_clipped_dx
>> dyin=lieb_dem_25m_clipped_dy  rain_val=2.0 manin_val=0.1
>> infil_val=13.0 depth=rsimwater.depth.18s disch=rsimwater.disch.18s
>> default nwalk=600505650, rwalk=600505650.000000
>> Killed
> 
> Here for NC:
> 
> g.region -d res=1000 -p
> r.slope.aspect elevation=elevation dx=elevation_dx dy=elevation_dy
> r.sim.water elevin=elevation dxin=elevation_dx dyin=elevation_dy  \
>        rain_val=2.0 manin_val=0.1 infil_val=13.0 \
>        depth=rsimwater.depth.18s disch=rsimwater.disch.18s
> ...
> WARNING: Infiltration exceeds the rainfall rate everywhere! No overland
>         flow.
> ...
> Number of iterations = 0 cells
> Time step = 129663.85 s
> GRASS 6.4.0svn (nc_spm_08):~ >
> 
> So no crash. But my region had way less pixels.
> 
>> ----
>> 
>> Since this resolution gives about 300 million cells in the region, I
>> progressively coarsened the resolution, but I get buffer overflows
>> even with just 2736 cells in the region (resolution = 00:01:00)
> 
> The question is; how big are the internal tmp files?
> Did you compile GRASS with large file support (--enable-largefile)?
> 
>> Below is an example of the error I got at a resolution of 1 minute.
>> The output at all resolutions (except 00:00:00.18) is similar:
> 
> Second possibility is a bug when having LatLong coordinates. I
> used a metric system.
> 
> ...
>> Time step = 0.00 s
>> *** buffer overflow detected ***: r.sim.water terminated
>> ======= Backtrace: =========
> 
> We would need a full backtrace (maybe not posted to the list)
> which requires GRASS compiled with debugging symbols.
> 
>> I can run the Spearfish example as shown in the r.sim.water manual
>> page and that region contains 2654802 cells.
> 
> Could you prepare a LatLong example with public data?
> 
>> My DEM is not rectangular and I'm setting the region to a vector file
>> that is an irregular boundary. So, the DEM has NULL values outside the
>> vector boundary but inside the region. Could this be a problem?
> 
> I don't think so.
> 
> Markus
> _______________________________________________
> grass-dev mailing list
> grass-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-dev