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Sprinkler irrigation scheme

S

shaider2

New member
Hi,

I have attached my irrigation parameterization options from the namelist.input. Irrigation.PNG I was intendinf to apply 8mm/day in 3 day frequency. However, my model is simulation 24 mm of precipitation every single day.
 
Your namelist.input looks fine to me. I guess we need to better understand the physical meanings of the relevant options:

Code: 
sf_surf_irr_scheme (max_dom)        = 0: no irrigation scheme


                                     = 1: channel scheme (in Noah only) 


                                     = 2: drip scheme 


                                     = 3: sprinkler scheme 


 


 irr_daily_amount (max_dom)          = daily equivalent irrigation water amount in mm (float, e.g. 5.7)


 irr_start_hour (max_dom)            = UTC start hour for irrigation (int, e.g. 5)


 irr_num_hours (max_dom)             = number of consecutive hours for irrigation (int, e.g. 3)


 irr_start_julianday (max_dom)       = Julian start day of irrigation (int, e.g. 135)


 irr_end_julianday (max_dom)         = Julian end day of irrigation (int, e.g. 255)


 irr_ph (max_dom)                    = 0: all the static IRRIGATION field is activated 


                                     = 1: pseudo random activation field: ensures repeatability across compilers 


                                     = 2: random activation field: results might depend on the compiler fortran RANDOM_SEED


 irr_freq (max_dom)                  = irrigation frequency in days (int, e.g. 3)

Please follow the above information to reset those namelist options, for example, try:

irr_num_hours = 0, 1

irr_freq = 0, 1

Let me know whether this gives you the result you expect.
 
Hi , thank you for the response. I don't want to apply precipitation everyday. I want to apply after every 3 days. Is there any possibilities for that?
 
There is no namelist option for what you intend to do.

You will need to modify the codes "phys/module_irrigation.F". Specifically, please look at the following piece:
Code: 
185       constants_irrigation=irr_freq*irr_daily_amount/(irr_num_hours*3600*rho(a,kms,b)*dz8w(a,kms,b)*100)


186       IF (irrigation(a,b).GE.0.1 .AND. irr_on.eq.1 ) THEN


187         CALL irr_calc_phase(irr_ph,phase,irr_rand_field_val(a,b),a,b,irrigation(a,b),irr_freq)


188         IF(irr_ph.EQ.0) THEN


189               qr_curr(a,kms,b)=qr_curr(a,kms,b)+irrigation(a,b)*constants_irrigation*dt


190         ELSE


191               IF(timing.EQ.int(phase))  THEN


192                    qr_curr(a,kms,b)=qr_curr(a,kms,b)+irrigation(a,b)*constants_irrigation*dt


193               END IF


194         END IF


195       END IF
 
Do I need to add the timing variable to pahse 0 option. As I understood earlier, timing of irigation is added based on the irrigation frequency also.
Besides, it will be nice if you can suggest what kind of change I can make.
Other than this I am also having trouble to separate my irrigation from natural precipitation in the RAINNC. Do you have any suggestions for this?
 
I am not an expert in irritation scheme, Sorry that I don't have answers to your question...

Probably you can refer to the literature and see whether. you can find helpful information.
 
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