About Nitrogen load output outlier and PARM86

[Javier Fernando Mendez Monroy]

Good morning.

I am modeling Total Nitrogen and I am obtaining an outlier value, at least 10 times the result of the outputs for soluble nitrogen.

Any suggestion or strategy to tackle this matter that you can kindly suggest me?

I am calibrating PARM 86 and in PARM1501 file appears empty. When I change for a value, the DWS file starts to appear with NaN outlets. I will appreciate any advice also in this matter.

Thanks.

[Luca]

Dear Javier,

Can you better explain what is happening? I understand that you are working with APEX1501 and you would like to change the value of PARM(86) that is missing (no value) in PARM1501.DAT. Is this the situation you are facing?

Looking at the code, the model should give you strange results with zero value for PARM(86). What value are you using? Suggested default value is 0.01.

Let me know and we can continue to work on this.

Luca

[Javier Fernando Mendez Monroy]

Dear Luca, thanks for your answer.

I am calibrating PARM 86 with APEX CUTE. I am obtaining a value close to 7.5. In file PARM1501 this field appears empty (blank), so I fill it with the number I found using APEX.xls editor, to be sure I am writing in the proper field, and I run APEX. After the DWS file started to appear some NaN outputs for Nutrients (Phosphorus and Nitrogen-.

Is there any problem with this parameter?, is it better to leave it blank?

Thanks for your time.

[Luca]

I don't think PARM(86) should be left blank because the model is not going to assign any default value to it. Just to be sure, PARM(86) affects the upward movement of soluble nitrogen in the soil. Is this what you want to calibrate?

Luca

[Javier Fernando Mendez Monroy]

Thanks for your answer.

Indeed I am using APEX1501. I calibrate PARM86 using APEX CUTE (DDS method). The obtained value was close to 7. I change this value in the PARM1501 file and the run te model.

As a result, some NaN outlets started to appear. If you have any suggestions,o if I should leave 0.01 as you mentioned before.

Thanks again.

[Luca]

According to the user manual, the value of PARM86 can be between 0.001 and 20.0 with a default value of 0.01. So, while a value of 7 is within range and acceptable, the NaN is a problem. What output variable is having NaN?

Luca