Page 1 of 1

Cosine function for variation of precipitation

Posted: Wed Jun 12, 2019 9:08 pm
by ghassemi
Hello,

Variations in potential evaporation and transpiration during the day can be generated with HYDRUS-1D using a sinusoidal shape function proposed by
Fayer (2000). Similarly, variation of precipitation can also be approximated in HYDRUS-1D using a cosine function.
I appreciate if anyone could help me to find the original reference for the cosine function.

Thank you,
Ali

Re: Cosine function for variation of precipitation

Posted: Wed Jun 12, 2019 11:00 pm
by Jirka
The reference is given in the HYDRUS-1D manual. J.

Re: Cosine function for variation of precipitation

Posted: Thu Jun 13, 2019 3:21 pm
by ghassemi
Hi Jirka,

Thank you for your quick reply.
Fayer (2000)'s paper only describes the variations in potential evaporation and transpiration during the day.
I am looking for a rational explanation for cosine distribution of daily precipitation as considered in HYDRUS-1D.

Thank you,
Ali

Re: Cosine function for variation of precipitation

Posted: Thu Jun 13, 2019 4:40 pm
by Jirka
It is some 20 years since I implemented this, so I do not remember all the details. I can see in the HYDRUS manual that I do not clearly reference this to Fayer (2000). Perhaps check the source code of the program that Fayer (2000) documents. If it is not there, then it may be only my modification. J.