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Modify geo_em.d04 based on landuse data


New member
I am using WRF model to run a real case in Dhaka, Bangladesh region to analyze the urban breeze. I am using a 4 nested domain, and i want the modify my geo_em.d04 data.

The issue is the landuse. I used two landuse types in the wrf default landuse: modis_landuse_20class_30s and modis_landuse_20class_15s. The first one overestimates the urban area in Dhaka and the second one underestimates it, especially in the south of Dhaka. I want to use modis_landuse_20class_15s but modify the urban landuse based on the landuse map I created using Landsat 8 OLI data (supervised classification).

I am attaching the maps. The urban area is indicated in red. I have the urban grids in my classified image. My aim is to convert the same grids in the LU_INDEX variable in the geo_em.d04 file to urban (=13). Since urban area is my primary concern and the urban breeze depends highly on the landuse, I must make such modification to get proper wrf_output.

The classified image is .tiff format and prepared using QGIS. How can I modify the geo_em.d04 file and use it to run the WRF model successfully?

Thank you.


  • modis_20class_15s.png
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  • landsat 8.jpg
    landsat 8.jpg
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I solved it. In case anyone comes across this post with a similar issue, I will briefly describe how I did it. After saving both the landuse data as nc file with lat-lon array, I opened them in QGIS and assigned the same map projection (WGS 84 / UTM 46N in my case). The purpose of using QGIS here was to check if the landuse maps overlapped and matched or not. Then, I made the high res data (Landsat) coarse and made it the same resolution with MODIS. Then, based on this resampled data, I changed the necessary grid points in geo_em.d04 to urban.