No FRC_URB2D generated in domain 3

[Liliputian_123]

Dear WRF experts,

I am creating a new FRC_URB2D file, but for some reason, it is not properly read and integrated by geogrid.

All my files are uploaded here including the namelist.wps, GEOGRID.TBL, and the binary files.

urban_fraction_experiments - Google Drive

drive.google.com

The urban fraction file is in the range of [0,100] (one byte). I used a scale_factor of 0.01 in the index file.
I am using MODIS 21 land use.

Any idea how to fix this?

I'll appreciate any help on this matter.

 

[kwerner]

Hi,
Your namelist.wps file has the path for 'geog_data_res' set to

geog_data_res     = 'modis_lakes+10m','modis_lakes+5m','modis_lakes+30s',

But in your GEOGRID.TBL file, you have the path for the FRC_URB2D field set to

  rel_path=default:solris/

meaning that if you set 'geog_data_res' to 'default' the geogrid program will see the new fractional dataset (assuming the 'solris' directory is in the same location as your other static directories - for e.g., in 'WPS_GEOG').
The default setting for landuse is the modis_lakes dataset, so you should change the parameter setting to

geog_data_res.  = 'default', 'default', default'

 

[Liliputian_123]

Hi Kwerner,

I followed your suggestion, but I'm still getting the same result.

Also attached is the plot of the urban fraction binary file. I ued Landsat2018 data

Attached are the screenshots. Why do domains 1 and 2 have values (actually the values are weird), while domain 3 has no value?
The figure sequence is for domain 1(top), domain 2 (mid), domain 3 (bottom)

 

[kwerner]

Regarding the reason why the values are zero for domain 3, it looks like the domain is probably just located in an area within domain 2, where the FRC_URB2D field is all zero (based on the FRC_URB2D values in your domain 2 plot), but I agree that the data don't match the map you provided. I'm not certain your index file is set up correctly, though I don't know what would need to be modified. I have a Python script I'm using to try to plot your tile, based on your index and I keep getting an error that the tile does not have the expected number of elements. I'm attaching that script in case you're interested in taking a look. I can also point you to this post, where another python script is suggested for plotting. I believe in that one, the "8" in the "b =" line is referring to the tile_z value, which is =1 for you. Regardless of which script I use, I run into tile size issues, which leads me to suspect the size is wrong in your index.

 

[Liliputian_123]

@kwerner,

You are correct. The problem is with the binary file. I got this working now.

 

[kwerner]

That's great news! Do you mind saying, specifically, what the issue was so that it may help someone else in the future? Thanks!

 

[Liliputian_123]

@kwerner, I just followed the tutorial in the Documentation (Chapter 3). The problem was in the way we wrote the urban fraction file.
Just follow the steps in Chapter 3 (Creating an urban fraction field from NLCD data)

 

[deatania]

Hi,
I have a similar problem.
I am using external sources of land use and urban fraction data.
I followed the steps in Chapter 3, Creating an urban fraction field from NLCD data.
But I used ArcGIS pro to convert the data into binary format.
The LU_INDEX were successfully generated in geo_em files.
And the LANDUSEF seemed to be generated from my external urban fraction data.
But the FRC_URB2D is all zero.
Can you help me to figure out why the FRC_URB2D was not generated?
I attached the binary of urban fraction data, the index file, GEOGRID.TBL, my namelist.wps, and the geo_em files.
Thank you.

 

[kwerner]

@deatania
In your GEOGRID.TBL.ARW file, under FRC_URB2D, you have the line

interp_option=default: average_gcell(1.0)+four_pt

Can you change that "1.0" to "2.0" and see if that helps? I ran geogrid with your namelist and FRC_URB2D data, but with 2.0 and it seems to work just fine.

 

[deatania]

@kwerner thank you for your suggestion. It has been solved now. Apparently, because I set "filename_digits=6" in the index file.

 

[kwerner]

Great! Thank you for updating the post with the solution.

 

[vongrads]

@kwerner did the NLCD data cover whole globe?

 

[kwerner]

@vongrads
No, it only covers the continental U.S. See this section of the WRF Users' Guide for details.

 

[vongrads]

thank you @kwerner. I also found link provide global urban fraction data which might useful A High-Resolution Dataset of Global Urban Fraction for Mesoscale Urban Modelling

 

[Tom]

Hi all:
I have a question during creating FRC_URB2D.I use the GlobeLand30 to create FRC_URB2D.the datatype is 2,but the uf.c(https://www2.mmm.ucar.edu/people/duda/uf/uf.c) must requre datatype to be 1.So I use python script or arcgis pro to convert the datatype.After converting datatype.then i use uf.c to create RFC_URB2D,For the output ,i use plot_tile.py to deal it,and then it shows the error at below.It means that the tile_x and tile_y has changeg.That‘’s why?
would you give me some idea to solve it ?

 

[kwerner]

@Tom
Since your question is somewhat different than the original question asked in this thread, will you please post your question as a new thread. This helps to keep the forum organized by single issues, which is better for readability and searchability. Thanks!