It's in mm/hr. Are these values normal, to me it seems like big values because they are ranging from 2000-4500, see below I just copied a few:
120795|4076||1|4076|4076|0|4076|0|0|0|4076 120796|4080||1|4080|4080|0|4080|0|0|0|4080 120797|4084||1|4084|4084|0|4084|0|0|0|4084 120798|4088||1|4088|4088|0|4088|0|0|0|4088 120799|4092||1|4092|4092|0|4092|0|0|0|4092 120800|4096||1|4096|4096|0|4096|0|0|0|4096 120801|4100||1|4100|4100|0|4100|0|0|0|4100 120802|4104||1|4104|4104|0|4104|0|0|0|4104 120803|4108||1|4108|4108|0|4108|0|0|0|4108 120804|4112||1|4112|4112|0|4112|0|0|0|4112 120805|4116||1|4116|4116|0|4116|0|0|0|4116 120806|4120||1|4120|4120|0|4120|0|0|0|4120 120807|4124||1|4124|4124|0|4124|0|0|0|4124 120808|4128||1|4128|4128|0|4128|0|0|0|4128 120809|4144||1|4144|4144|0|4144|0|0|0|4144 120810|4148||1|4148|4148|0|4148|0|0|0|4148 120811|4152||1|4152|4152|0|4152|0|0|0|4152 120812|4156||1|4156|4156|0|4156|0|0|0|4156 2010/6/22 Micha Silver <mi...@arava.co.il> > On 22/06/2010 13:08, Sandile Gumede wrote: > > Thanks, I finally got the results. > > That's good to hear. > > > Now the question I would like to ask is that, from these columns I got the > values but which unit are these values are measured? Is it (mm) or ? > > Well, that depends on the units of the raster. If the raster values are mm. > then each column represents mm per *raster cell*. So if you have a rainfall > raster with values in mm., and resolution of 10 meters, then the numbers in > the columns are mm/100sq.m. > -- > Micha > > > > On Sat, Jun 19, 2010 at 9:57 PM, Micha Silver <mi...@arava.co.il> wrote: > >> Hello Sandile: >> I tried to duplicate your steps and it seems to work for me. >> Here's what I did: >> >> >> wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tif >> wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tfw >> >> gdalinfo 3B42RT.2010032900.1day.tif >> Driver: GTiff/GeoTIFF >> Files: 3B42RT.2010032900.1day.tif >> 3B42RT.2010032900.1day.tfw >> Size is 1440, 480 >> Coordinate System is `' >> Origin = (-180.000000000000000,60.000000000000000) >> Pixel Size = (0.250000000000000,-0.250000000000000) >> .... >> >> ---- Note: no projection info above ---- >> >> ---- Now I use the -projwin option of gdal_translate to select a small >> window >> gdal_translate -a_srs EPSG:4326 -projwin 34.0 33.0 36.0 29.0 >> 3B42RT.2010032900.1day.tif rainfall_il.tif >> >> ---- GEOGCS entry now shows 4326 ---- >> >> g.mapset map=ASTER_DEM loc=WGS84 >> ----- A location setup as EPSG:4326---- >> >> r.in.gdal israel.tif out=rainfall_il >> >> r.univar rainfall_il >> 100% >> total null and non-null cells: 77760000 >> >> total null cells: 0 >> >> Of the non-null cells: >> ---------------------- >> n: 77760000 >> minimum: 0 >> maximum: 34 >> range: 34 >> mean: 0.364583 >> mean of absolute values: 0.364583 >> standard deviation: 3.45241 >> variance: 11.9192 >> variation coefficient: 946.948 % >> sum: 28350000 >> >> >> ----- Now using an existing catchment vector map ---- >> v.rast.stats vect=arava_wsheds rast=rainfall_il colpre=precip >> v.info -c arava_wsheds >> Displaying column types/names for database connection of layer 1: >> INTEGER|cat >> CHARACTER|label >> DOUBLE PRECISION|area_km >> INTEGER|precip_n >> DOUBLE PRECISION|precip_min >> DOUBLE PRECISION|precip_max >> DOUBLE PRECISION|precip_range >> DOUBLE PRECISION|precip_mean >> DOUBLE PRECISION|precip_stddev >> DOUBLE PRECISION|precip_variance >> DOUBLE PRECISION|precip_cf_var >> DOUBLE PRECISION|precip_sum >> >> ---- and some values ---- >> >> v.db.select arava_wsheds >> >> cat|label|area_km|precip_n|precip_min|precip_max|precip_range|precip_mean|precip_stddev|precip_variance|precip_cf_var|precip_sum >> 21|Jordan|1055.231692|2|0|0|0|0|0|0||0 >> 19|Hidan|987.811979|2|0|0|0|0|0|0||0 >> 28|Og|124.122969||||||||| >> 36|Zarqa|273.606213||||||||| >> 24|Kidron|122.460114||||||||| >> 9|Darga|289.012122||||||||| >> 6|Arugot|236.365116|1|0|0|0|0|0|0||0 >> 26|Mujib|1277.546513|2|0|0|0|0|0|0||0 >> >> ---- (Many catchments have 0 or no value because of the small region I >> chose. The global data is 1/4 degree resolution and my region is only 2 deg >> E-W.)---- >> >> HTH... >> -- >> Micha >> >> >> >> On 06/17/2010 12:50 PM, Sandile Gumede wrote: >> >> Hi >> >> It is still giving me -NULL value error. >> >> Do you think maybe its the way I downloaded my rainfall data? This is the >> site where I downloaded my data sets* >> ftp://trmmopen.gsfc.nasa.gov/pub/gis/ *and this data covers the whole >> world, the only thing I did was to clip a specific region (using >> coordinates) that is in South Africa to do my analysis. I used a bash script >> to download and project the data, see below: >> >> >> #!/bin/bash >> >> wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tif >> wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tfw >> >> gdal_translate -of GTiff -co "PROFILE=GeoTIFF" -co "INTERLEAVE=PIXEL" -co >> "COMPRESS=LZW" -co "TILED=YES" -a_srs EPSG:4326 -a_ullr 18.2987501 >> -33.6795831 19.1712501 -34.3487498 3B42RT.2010032900.1day.tif >> TRMMLast1day.tif >> >> >> >> >> On Thu, Jun 17, 2010 at 8:41 AM, Sandile Gumede <akasand...@gmail.com>wrote: >> >>> Hi >>> >>> It is still giving me -NULL value error. >>> >>> Do you think maybe its the way I downloaded my rainfall data? This is the >>> site where I downloaded my data sets* >>> ftp://trmmopen.gsfc.nasa.gov/pub/gis/ *and this data covers the whole >>> world, the only thing I did was to clip a specific region (using >>> coordinates) that is in South Africa to do my analysis. I used a bash script >>> to download and project the data, see below: >>> >>> >>> #!/bin/bash >>> >>> wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tif >>> wget ftp://trmmopen.gsfc.nasa.gov/pub/gis/3B42RT.2010032900.1day.tfw >>> >>> gdal_translate -of GTiff -co "PROFILE=GeoTIFF" -co "INTERLEAVE=PIXEL" -co >>> "COMPRESS=LZW" -co "TILED=YES" -a_srs EPSG:4326 -a_ullr 18.2987501 >>> -33.6795831 19.1712501 -34.3487498 3B42RT.2010032900.1day.tif >>> TRMMLast1day.tif >>> >>> >>> >>> 2010/6/15 Micha Silver <mi...@arava.co.il> >>> >>>> On 15/06/2010 14:35, Sandile Gumede wrote: >>>> >>>> Hi >>>> If I run g.region rast=rainfall -p, I get: >>>> >>>> OK, what you've done here is change the current region to match the >>>> raster "rainfall". >>>> Can you now try: >>>> v.rast.stats -c vect=catchments rast=rainfall pref=precip >>>> >>>> >>>> >>>> >>>> projection: 3 (Latitude-Longitude) >>>> zone: 0 >>>> datum: wgs84 >>>> ellipsoid: wgs84 >>>> north: 33:40:46.49916S >>>> south: 34:20:55.49928S >>>> west: 18:17:55.50036E >>>> east: 19:10:16.50036E >>>> nsres: 0:00:05.01875 >>>> ewres: 0:00:02.18125 >>>> rows: 480 >>>> cols: 1440 >>>> cells: 691200 >>>> >>>> and If I run r.univar rainfall, I get the following output: >>>> >>>> 100% >>>> total null and non-null cells: 691200 >>>> total null cells: 0 >>>> >>>> Of the non-null cells: >>>> ---------------------- >>>> n: 691200 >>>> minimum: 0 >>>> maximum: 3094 >>>> range: 3094 >>>> mean: 22.0228 >>>> mean of absolute values: 22.0228 >>>> standard deviation: 76.1639 >>>> variance: 5800.94 >>>> variation coefficient: 345.841 % >>>> sum: 15222164 >>>> >>>> >>>> >>>> On Tue, Jun 15, 2010 at 12:22 PM, Hamish <hamis...@yahoo.com> wrote: >>>> >>>>> Micha wrote: >>>>> > The only unusual thing I notice above is that the resolution settings >>>>> > for the raster are different N-S and E-W. This came from the original >>>>> > tiff (see below) which also has rectangular pixels, >>>>> >>>>> that is perfectly normal for a lat/lon map away from the equator. >>>>> longitude scales a cos(lat). >>>>> >>>>> >>>>> > (the v.rast.stats module creates a temp raster at the *current >>>>> region's >>>>> > resolution* settings, which might be different from this rainfall >>>>> > raster's rectangular resolution...) >>>>> >>>>> the results of: >>>>> >>>>> g.region -p rast=mapname >>>>> r.univar mapname >>>>> >>>>> >>>>> could help. >>>>> >>>>> >>>>> Hamish >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> -- >>>> Kind Regards >>>> TS Gumede >>>> CSIR, Meraka Institute >>>> 072 258 1650 >>>> >>>> >>>> This mail was received via Mail-SeCure System. >>>> >>>> >>>> >>>> -- >>>> Micha Silverhttp://www.surfaces.co.il/ >>>> Arava Development Co. +972-52-3665918 >>>> >>>> >>>> >>> >>> >>> -- >>> Kind Regards >>> TS Gumede >>> CSIR, Meraka Institute >>> 072 258 1650 >>> >>> >> >> >> -- >> Kind Regards >> TS Gumede >> CSIR, Meraka Institute >> 072 258 1650 >> >> >> This mail was received via Mail-SeCure System. >> >> >> >> -- >> Micha Silver >> Arava Development Co. +972-52-3665918http://surfaces.co.il >> >> > > > -- > Kind Regards > TS Gumede > CSIR, Meraka Institute > 072 258 1650 > > > This mail was received via Mail-SeCure System. > > > > -- > Micha Silverhttp://www.surfaces.co.il/ > Arava Development Co. +972-52-3665918 > > -- Kind Regards TS Gumede CSIR, Meraka Institute 072 258 1650
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