Hi, Can anyone help!
On Wed, Jul 14, 2010 at 1:31 PM, Sandile Gumede <akasand...@gmail.com>wrote: > Hi, > > I'm using GTOPO30 DEM data and TRMM (rainfall) data, I selected the data > for the whole of africa but I'm getting an error when executing > v.rast.stats. > > Here is a step-by-step of what I did: > > 1. GTOPO30 DEM > - downloaded e020n10,w020s10,e020n40,w020n40 compressed files from " > ftp://edcftp.cr.usgs.gov/pub/data/gtopo30/global/". > - decompressed all the above files. > - Added "PIXELTYPE SIGNEDINT" in all .HDR files > - warp merged all the .DEM file with "gdalwarp *.DEM Africa.tif" > command. > - projected it with "gdal_translate -a_srs EPSG:4326 Africa.tif > DEM.tif" > > 2. TRMM "rainfall" data > - downloaded 3B42RT.2010061503.1day.tif,3B42RT.2010061503.1day.tfw > from "". > - projected it with "gdal_translate -a_srs EPSG:4326 -projwin -20 40 > 60 -60 3B42RT.2010061503.1day.tif TRMM.tif ". > > Then, imported the two data sets: > > r.in.gdal in=/home/tgumede1/grassdem/ict4eo/DEM.tif out=dem > > Projection of input dataset and current location appear to match > 100% > r.in.gdal complete. Raster map <dem> created. > > g.region rast=dem > > r.in.gdal in=/home/tgumede1/grassdem/ict4eo/CapeTown_TRMMs.tif out=rainfall > target=CapeTown > > Projection of input dataset and current location appear to match > 100% > r.in.gdal complete. Raster map <rainfall> created. > > r.watershed elevation=dem accumulation=acc drainage=direction stream=str > basin=catch memory=300 threshold=100000 > > SECTION 1a (of 5): Initiating Memory. > SECTION 1b (of 5): Determining Offmap Flow. > 100% > SECTION 2: A * Search. > 100% > SECTION 3: Accumulating Surface Flow. > 100% > SECTION 4: Watershed determination. > 100% > SECTION 5: Closing Maps. > 100% > > Q: How do one really know the exact threshold value? > > r.to.vect in=catch out=catchments feature=area > > Extracting areas... > 100% > 100% > Building topology for vector map <catchments>... > Registering primitives... > 134246 primitives registered > 701002 vertices registered > Building areas... > 100% > 44645 areas built > > 1 isles built > Attaching islands... > 100% > Attaching centroids... > 100% > Number of nodes: 89602 > Number of primitives: 134246 > > Number of points: 0 > Number of lines: 0 > Number of boundaries: 89604 > Number of centroids: 44642 > Number of areas: 44645 > Number of isles: 1 > Number of areas without centroid: 3 > r.to.vect complete. > > > g.region rast=rainfall > > v.rast.stats vector=catchments raster=rainfall colprefix=precip > WARNING: Area without centroid (may be OK for island) > WARNING: Area without centroid (may be OK for island) > WARNING: Area without centroid (may be OK for island) > > DBMI-DBF driver error: > SQL parser error: syntax error, unexpected NULL_VALUE processing 'NULL' > in statement: > UPDATE catchments SET precip_cf_=-NULL WHERE cat=17 > > Error in db_execute_immediate() > > ERROR: Error while executing: 'UPDATE catchments SET precip_cf_=-NULL WHERE > cat=17' > > > - output of r.info -g > > r.info -g rainfall > north=40 > south=-60 > east=60 > west=-20 > > - output of v.info > > v.info -g catchments > north=40 > south=-60 > east=60 > west=-20 > > top=0.000000 > bottom=0.000000 > > output of r.info > > Type of Map: raster Number of Categories: 2559 > Data Type: > CELL > Rows: > 400 > Columns: > 320 > Total Cells: > 128000 > Projection: > Latitude-Longitude > N: 40N S: 60S Res: > 0:15 > E: 60E W: 20W Res: > 0:15 > Range of data: min = 0 max = > 2559 > > > Data > Description: > generated by > r.in.gdal > > > > Comments: > r.in.gdal input="/home/tgumede1/grassdem/ict4eo/CapeTown_TRMMs.tif" > \ > output="rainfall" target="CapeTown" > > > - output of r.univar > > r.univar rainfall > 100% > total null and non-null cells: 115200000 > > total null cells: 0 > > Of the non-null cells: > ---------------------- > n: 115200000 > minimum: 0 > maximum: 2559 > range: 2559 > mean: 22.4897 > mean of absolute values: 22.4897 > standard deviation: 83.1312 > variance: 6910.79 > variation coefficient: 369.642 % > sum: 2590809300 > > > > > > > -- > Kind Regards > TS Gumede > CSIR, Meraka Institute > 072 258 1650 > > -- Kind Regards TS Gumede CSIR, Meraka Institute 072 258 1650
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