1/3 arc-second DEM national map data into WPS geogrid

Questions related to the use of new landuse, or geographical static data, or to modifications to the existing data
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gjduine
Posts: 4
Joined: Thu Nov 08, 2018 10:43 pm

1/3 arc-second DEM national map data into WPS geogrid

Post by gjduine » Wed Feb 24, 2021 9:34 pm

Hello,

I’m looking to incorporate 1/3 arc second DEM data into WRF from national map database (https://apps.nationalmap.gov/downloader/#/). Specifically, from this website I used 1/3 arc-second DEM under Elevation Products (3DEP). I used the .tif file, then used gdal commands to convert into binary format, and changing filenames to respect the geogrid rules considering 00001-10812.00001-10812 etc.

The gdal command was something in this style:
gdal –of ENVI foo.fit temp.dat

The projection works fine, but the values are in the order 10^9. See the 250 m domain (domain 3) in the attached figure. For reference, I also attached a figure that shows all desired domains, but using the standard 30s input domain. With some imagination I can see that using the 1/3 arc-second data the expected terrain elevation is present with a resolved valley. However, the values for terrain elevation are in the range of 10^9.

Using the .flt instead .tif and convert it to binary format gave similar results to what is posted here. I used some of the .hdr output to get some sense of the .tif file, and it shows that in the .tif data, the terrain elevation are in the expected value (0-1500 m). So, my conclusion was that either gdal conversion goes wrong, or my index file has wrong definitions. I’ve been looking into most options of the index file like endian, tile_bdr or word_size but that results in wrong projections, or even less normal values for terrain elevation.

I also looked into the convert_geotiff program that could produce the correct index file, but so far I have not been lucky to install this on the local machine.

Has anyone been successfull using this dataset? Or, perhaps if anyone has some kind of a hint to a solution that would be great.

Thanks for your help,

Gert-Jan
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sbareg_d03_13s.png
sbareg_d01-d04_30s.png

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: 1/3 arc-second DEM national map data into WPS geogrid

Post by kwerner » Mon Mar 08, 2021 4:57 pm

Hi,
This may lie outside the scope of what we are able to support, but I've passed this along to a colleague who may know. If so, they will post a response. Otherwise, hopefully someone in the community will be able to assist.
NCAR/MMM

gjduine
Posts: 4
Joined: Thu Nov 08, 2018 10:43 pm

Re: 1/3 arc-second DEM national map data into WPS geogrid

Post by gjduine » Fri Mar 12, 2021 9:47 pm

Hi,

thanks for your reply. I just wanted to confirm that I managed to install and run convert_geotiff following procedures written up here https://wiki.openwfm.org/mediawiki/inde ... _real_data and here https://wiki.openwfm.org/wiki/How_to_co ... or_Geogrid

so this uses the wrfxpy environment in python. Then, using the downloaded dem tif file described below, ran the code using ZSF for terrain elevation, which will give HGT_M input for geogrid. The program gives index file directly, which is perfect.

I'm also interested in using land cover at similar resolution (order of 10-30 meter). Nevertheless, there's somehow no conversion available for land use in the convert_geotiff (only fuel category for fire). I will follow up in a different post however as it considers a different problem.

Thanks,

Gert-Jan

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