The irrigation amount is too large in NoahMP Crop module

[qingling]

I conducted flood irrigation experiments on corn, wheat, and cotton in Xinjiang in 2000, and these data have been replaced in wps/crop/crop types using the WRFV4.6 model.

Question 1: Based on the CROPCAT variable in the wrfout, I found that it seems that only corn is set to 1, while the wheat in the region where crop type (i, 5, j)>=0.5 is 0. What is the value of default_crop_table in the initialization code of module_sf_noahmpdrv.F? From where?

noahmp/drivers/wrf/module_sf_noahmpdrv.F at 848f54ad3d28c4303151fe5ad83724e232694422 · NCAR/noahmp

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Question 2: I found that the IRFIVOL with corn in the wrfout reached 53104.334mm throughout the year. This is obviously unreasonable. So I checked the FVEG of these grid points and found that the value for the whole year was 0.95. As shown in the following figure.

At the same time, I also checked the initialization code of module_sf_noahmpdrv.F and found that the FVEG value was directly set to 0.95. I would like to ask why I cannot dynamically simulate FVEG based on FVEG=1. - EXP (-0.52 * (LAI+SAI)) with dveg=2?

noahmp/drivers/wrf/module_sf_noahmpdrv.F at 848f54ad3d28c4303151fe5ad83724e232694422 · NCAR/noahmp

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noahmp/src/module_sf_noahmplsm.F at e5c0859874407859936739e8be8741f9aed369ee · NCAR/noahmp

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Looking forward to everyone's reply and answer!!

 

[cenlinhe]

1. Currently, Noah-MP can only simulate corn (crop type=1) and soybean (crop type=2) in WRF.
2. The default_crop_table in the MPTABLE.TBL is set to 0, which means the crop is treated as a dynamically growing natural vegetation with a set of bulk crop parameters in the veg section above the crop section in MPTABLE.TBL.
3. Did you activate irrigation during your model spinup period? If so, that may be the cause for the very large IRFIVOL because it accumulates from the very beginning of the simulation (including spinup period).
4. The FVEG is set to 0.95 for the max veg fraction and the dynamic change is only applied to LAI during crop growth. This is more reasonable compared to having a changing FVEG without land cover change process, because the crop is in the field during the growth and as it grows, the major change is its LAI and SAI. You can also use the FVEG=1. - EXP (-0.52 * (LAI+SAI)) formulation, which you need to manually change the code to make it work.

 

[qingling]

1. Currently, Noah-MP can only simulate corn (crop type=1) and soybean (crop type=2) in WRF.
2. The default_crop_table in the MPTABLE.TBL is set to 0, which means the crop is treated as a dynamically growing natural vegetation with a set of bulk crop parameters in the veg section above the crop section in MPTABLE.TBL.
3. Did you activate irrigation during your model spinup period? If so, that may be the cause for the very large IRFIVOL because it accumulates from the very beginning of the simulation (including spinup period).
4. The FVEG is set to 0.95 for the max veg fraction and the dynamic change is only applied to LAI during crop growth. This is more reasonable compared to having a changing FVEG without land cover change process, because the crop is in the field during the growth and as it grows, the major change is its LAI and SAI. You can also use the FVEG=1. - EXP (-0.52 * (LAI+SAI)) formulation, which you need to manually change the code to make it work.

Thank you for your reply. I have already resolved the above issues. About 3, setting the opt_run option to 1 instead of the default value of 3 can restore IRFIVOL to normal after multiple experiments.

 

[Huimin97]

I am currently working on a crop–climate simulation using WRF 4.5 coupled with the Noah‑MP land surface scheme. The model runs successfully, but I have noticed that LAI stays very low and almost constant throughout the entire maize growing season. In other words, the model does not show any sign of dynamic crop growth.
I am not sure what is causing this issue. I will attach my namelist.input and MPTABLE.TBL files . Any support or suggestions would be greatly appreciated.

 

[qingling]

I am currently working on a crop–climate simulation using WRF 4.5 coupled with the Noah‑MP land surface scheme. The model runs successfully, but I have noticed that LAI stays very low and almost constant throughout the entire maize growing season. In other words, the model does not show any sign of dynamic crop growth.
I am not sure what is causing this issue. I will attach my namelist.input and MPTABLE.TBL files . Any support or suggestions would be greatly appreciated.

Hi, Huimin. I have replied you in another thread.