Hi all,
The flooding irrigation is not explicitly modeled in the crop irrigation module of CLM5. As far as I know, the rice paddies are always flooded in their growing seasons. The biophysical impact of this flooding irrigation (on air temperature and humidity) might be important in my research. Hence, I am trying to 'imitate' the impact of flooding irrigation by modifying the crop parameters of irrigated_rice, and here are the modifications I did:
By default, the irrigation flux for all irrigated crops is calculated using the same irrigation parameters in table 2.26.4 here: 2.26. Crops and Irrigation — ctsm release-clm5.0 documentation
In the IrrigationMod.F90, for the irrigated_rice patches, I changed the code so that the h2osoi_liq_target (target soil moisture) of them always equals the saturated soil moisture of that soil layer (set the relsat_target_col=1.0). And the irrig_length is 86400s (one day) for the irrigated_rice because the rice paddies are always flooded. The modified code can be found at https://github.com/keerzhang1/Flood_Irrig/blob/main/src/biogeophys/IrrigationMod.F90.
I think these modifications ensure that there is always irrigation_flux going into the ground when the soil moisture is not saturated for the irrigated rice patches. I know that these simple modifications still cannot represent the complete impacts of flooding irrigation, but the irrigation activity now is more similar to 'flooding irrigation' in that there is always abundant soil moisture for evaporation (and I only focus on the biophysical results like temperature, humidity, and sensible heat flux).
I wonder if this is an effective and reasonable trick to imitate flooding irrigation? Does anyone have suggestions/ comments on better representing the flooding irrigation in CLM5? Any insights are much appreciated! Thank you!
The flooding irrigation is not explicitly modeled in the crop irrigation module of CLM5. As far as I know, the rice paddies are always flooded in their growing seasons. The biophysical impact of this flooding irrigation (on air temperature and humidity) might be important in my research. Hence, I am trying to 'imitate' the impact of flooding irrigation by modifying the crop parameters of irrigated_rice, and here are the modifications I did:
By default, the irrigation flux for all irrigated crops is calculated using the same irrigation parameters in table 2.26.4 here: 2.26. Crops and Irrigation — ctsm release-clm5.0 documentation
In the IrrigationMod.F90, for the irrigated_rice patches, I changed the code so that the h2osoi_liq_target (target soil moisture) of them always equals the saturated soil moisture of that soil layer (set the relsat_target_col=1.0). And the irrig_length is 86400s (one day) for the irrigated_rice because the rice paddies are always flooded. The modified code can be found at https://github.com/keerzhang1/Flood_Irrig/blob/main/src/biogeophys/IrrigationMod.F90.
I think these modifications ensure that there is always irrigation_flux going into the ground when the soil moisture is not saturated for the irrigated rice patches. I know that these simple modifications still cannot represent the complete impacts of flooding irrigation, but the irrigation activity now is more similar to 'flooding irrigation' in that there is always abundant soil moisture for evaporation (and I only focus on the biophysical results like temperature, humidity, and sensible heat flux).
I wonder if this is an effective and reasonable trick to imitate flooding irrigation? Does anyone have suggestions/ comments on better representing the flooding irrigation in CLM5? Any insights are much appreciated! Thank you!