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How to alter landuse input data

Hello,

I am trying to run an experiment where I change the landuse categories around a windfarm to hopefully get better wind speed forecasts. My question branches off of this previous post which is what files should I target in order to change these values? My aim is to create a new landuse category for my area of focus and populate the VEGPARM.TBL with the new category and the associated values for it. From what I gathered from this forum and the user manual, it should be the geographic static data, namely the modis_landuse_20class_30s_with_lakes.tar.bz2 file. Also, what file format is this in and how would I physically go about changing these values? I would love some advice on my approach from someone more experienced in WRF.

Thanks in advance, please let me know if you require any further information.
 
If your purpose is to get better results over a wind farm area, I would suggest that you manually modify landuse type over that area instead of creating a new landuse type data, because the latter involves complicated work and the impact is greatly uncertain.
We provide a utility that enables people to modify WRF-related data. Please download the code from https://www2.mmm.ucar.edu/wrf/src/read_wrf_nc.f
You can use this code to modify landuse type over the area you are interested, and you can also modify values in VEGPARM.TBL based on your case. Note that values in the table are specified empirically and users can always make changes to achieve better results.
Hope this is helpful for you.
 
Hi Ming,
Thank you so much for your help. I took your advice and used the code you linked to alter the LU_INDEX in my d03 metgrid file for the area of interest. However, when I ran WRF using the edited metgrid files, my new LU_INDEX data did not carry over, and the model ran with the default landuse over my area of interest. Can you please advise on what I am doing wrong? Is editing the metgrid file before running WRF the correct method of altering the landuse over a certain area?
Attached are figures from ncview of the input metgrid file and wrfout showing the discrepancy.
Thank you in advance!
1738615266558.png1738615233357.png
 
can you look at your wrfinput_d03 file with and without your modification ? I expect that you should see different lu_index in the two files.

in your namelist.input, please also set feeback = 0.
 
Hi Ming,
feedback was already set = 0 when running the case I shared above.
LU_INDEX in the wrfinput file created through the modified metgrid files look the same as the wrfout file I shared above. I ran real.exe with the unmodified metgrid files and got the same result from that wrfinput_d03 file.
Should I be changing LU_INDEX in the wrfinput_d03 file instead of/along with the megrid files?
 
Please change LU_INDEX in your wrfinput_d03 and set feedback = 0, the try again.

I am perplexed by your case in that, LU_INDEX in wrfinput is derived from met_em files. If you change LU_INDEX in met-em, then it should be shown in wrfinput. I don't know yet why changes in met_em are not presented in wrfinput...

Anyway, change LU_INDEX in wrfinput should work for your goals.
 
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