Re: [GRASS-user] Opening a shape file in GRASS 6.4.3
Sonali wrote: I have redone the shape file, I am attching it again, and this is the error I get when I am trying to open it. The location is in india and spans two UTM zones and therefore I used lat lons Projection of input dataset and current location appear to match Layer: Meghalay DBMI-DBF driver error: ERROR: Unable to create table: 'create table Meghalay (cat integer, TYPE varchar ( 10 ), IDENT varchar ( 24 ), LAT double precision, LONG double precision, Y_PROJ double precision, X_PROJ double precision, NEW_SEG varchar ( 10 ), DISPLAY varchar ( 10 ), COLOR varchar ( 10 ), ALTITUDE double precision, DEPTH double precision, TEMP double precision, TIME varchar ( 20 ), MODEL varchar ( 20 ), FILENAME varchar ( 254 ), LTIME varchar ( 20 ))' Hi, perhaps TIME is a SQL reserved keyword, so you have to change that column name. (maybe TYPE too) http://grasswiki.osgeo.org/wiki/SQL you can use the v.in.ascii columns= option to do that. [hint: cut and paste the above as a starting point] Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] SRTM r.watershed at multiple scales
Hi jencor808, I can only recommend using SRTM for subbasin delineations. We are using it on a regular basis in our hydrological modelling working group. You'll have to play around with thresholds a little. I use different thresholds for different areas of my catchment (eg. in mountainous regions I'd want smaller subbasins). By masking those areas and run r.watershed several times, you can vary your thresholds and then patch the different subbasin rasters back together. As the r.watershed algorithm often leaves small areas at the edges uncovered, you'll have to fill those before or after patching, otherwise you'll have holes in your subbasin map. You can also get rid of small subbasins by converting your subbasin raster into a vector map and then run v.clean remove small areas (check manual) Hope it helps. I have got a python/GRASS script that is station-based that does the varying thresholds for you and all the cleaning etc. Let me know if you'd want to give that a try. Regards, Michel On 08/16/2013 06:51 PM, jencor808 wrote: Hello all~ I'm working with SRTM data and trying to produce watershed maps in Honduras. For most of the country, the threshold seems to work great at 10, but this is not the case on the shore - those watersheds are neglected likely due to their smaller scale. Does anyone have experience merging multiple scales? Does this make sense? I'd rather not reduce my threshold or the whole country because those watersheds seem too small. As an aside, what do people think about using SRTM for watershed mapping in the first place - given it is a surface model and not a DEM. -- View this message in context: http://osgeo-org.1560.x6.nabble.com/SRTM-r-watershed-at-multiple-scales-tp5072884.html Sent from the Grass - Users mailing list archive at Nabble.com. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] LANDSAT 8 updates
FYI some LANDSAT 8 news and updates http://landsat.usgs.gov/about_LU_Vol_7_Issue_4.php - Landsat 8 Pre-WRS2 Data Available - Landsat 8 Data Products - What have we learned? - Additional Information on Landsat 8 Reflectance and Radiance Conversions - Landsat 8 Thermal Infrared Sensor (TIRS) Calibration Notice [...] - best regards Helmut -- View this message in context: http://osgeo-org.1560.x6.nabble.com/LANDSAT-8-updates-tp5073648.html Sent from the Grass - Users mailing list archive at Nabble.com. ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
