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Replacing new land use data into MODIS WPS-GEOG

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maggieooi

New member
Dear all,

I am trying to replace land use data processed from ArcGIS into the WPS_GEOG/modis_landuse_20class_30s_with_lakes.
Here is some steps that I took:

1) Produce the LU data in ArcGIS convert it into geotiff file (with 33 land use types, including the urban 31,32,33)

2) Run convert_geotiff for the geotiff file
Code:
./convert_geotiff -c 33 -w 1 -t 1200 -b 0 lu20001.tif

3) Identify the location of LU map and rename the convert_geotiff output as 33601-34800.10801-12000 and copy to WPS_GEOG/modis_landuse_20class_30s_with_lakes folder (I have backup the original file)

4) Include "missing_value=34" in index file
Code:
type=categorical
category_min=1
category_max=33
projection=regular_ll
dx=0.00833333
dy=0.00833333
known_x=1.0
known_y=1.0
known_lat=-89.99583
known_lon=-179.99583
wordsize=1
tile_x=1200
tile_y=1200
tile_z=1
units="category"
description="Noah-modified 21-category IGBP-MODIS landuse"
mminlu="MODIFIED_IGBP_MODIS_NOAH"
missing_value=34
iswater=17
islake=21
isice=15
isurban=13
5) Run geogrid.exe, output without any warning message

6) I plotted the LU_INDEX of both d01 and d02 domain. d01 looks ok maybe because the resolution is coarse, but d02 has a strange category (17) on the left border of the LU file I replaced.
(the land use category of 19-21 of the map is 31-33)
d01:
https://user-images.githubusercontent.com/52151758/146890871-a0fc1dd0-7c38-46db-8077-2cc78bfdf53f.PNG
d02:
https://user-images.githubusercontent.com/52151758/146898323-21ed2801-cb7e-4597-9c2c-add62bef1836.png

I checked back the geotiff file in ArcGIS, the area with missing value does have value and looks fine.
Is there any steps that I missed during the processing?
Thanks!

Best regards,
Maggie
 
Maggie,
The steps you did look fine and I don't think you miss anything. The issue shown in D02 could possibly be caused by interpolation in WPS. In GEOGRID.TBL, you can choose "nearest_neighbor", "average_gcell(0.0)", "four_pt" etc. for interpolation. Can you try the option "average_gcell(0.0)" , i.e.,

change the line
interp_option = modis_30s_lake:nearest_neighbor
to
interp_option = modis_30s_lake:average_gcell(0.0)

Please let me know whether the result is better?
 
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