Subject: reference scenario Posted: 12/4/2024 Viewed: 441 times
Hello!
I'm working on the soil moisture method, I have four catchment, the base year is 2021 and the reference scenario is up to 2050.
i would like to ask about after entering all the data in the results of the reference scenario for each sub-basin is variable during the years and not constant, although I did not change the climate data or the river discharge in the reference scenario.
please tell me if Is this correct ???
Could you please clarify a bit? Are you asking about the values of the results, or the input data? Which variable?
-Doug
Eng. Haya Mando
Subject: Re: reference scenario Posted: 12/15/2024 Viewed: 278 times
Apologies for the delay
I will clarify my question, the water demand values in the reference scenario of my model are not fixed in the catchment nodes even though I did not modify the reference scenario.
Shouldn't the current accounts be the same as the reference scenario if we don't modify the reference scenario?
Domestic water demand sites nodes remained constant and did not change during the time period from 2020 to 2050, but agriculture changed their values.
Please guide me
Mr. Doug Chalmers
Subject: Re: reference scenario Posted: 12/16/2024 Viewed: 243 times
Haya,
The agriculture demand in your catchment sites will be tied to the climate data, which is likely why it varies. During times of higher precipitation and higher soil moisture, your irrigation demand will be lower. Even if you do not change the files that your climate data reads in your scenario, your climate data still varies across your years based on time-series input data, correct?
If you have not done so already, please see the result variables of Theoretical Catchment Irrigation Demand, and Annual Theoretical Catchment Irrigation Shortfall. These may be useful to you. Please see the Help in WEAP for more details.
Yes, I know that irrigation is related to climate data and soil moisture, but I only entered the rainfall data for 2021 and then cycled for the rest of the years, so I was confused if I didn't change the climate data or the parameters of the soil moisture method, why would the irrigation water requirement values change in the reference scenario?
Kind Regards,
Mr. Doug Chalmers
Subject: Re: reference scenario Posted: 12/17/2024 Viewed: 188 times
What is the soil moisture result at the start of each year? Does it vary by year? Does your catchment have unmet demand in the results? Is the streamflow result just upstream of your catchment the same for all years?
It is possible that your catchments have varying levels of soil moisture, and therefore different irrigation demands to bring it back to the soil moisture specified in the irrigation inputs.
Yes, the soil moisture is vary by year, as it remained the same value for the first six years and then the moisture value varied for the rest of the years, and yes, the watershed is unmet demand in the results.
the stream flow upstream in the watershed is the same in all years.
Haya
Mr. Doug Chalmers
Subject: Re: reference scenario Posted: 12/18/2024 Viewed: 168 times
I believe your varying soil moisture would explain the change in demand then. Your supply is not able to achieve all of the irrigation demand (based on the fact that you have unmet demand), and therefore your catchment doesn't receive enough water and its soil moisture decreases as a result. The demand changes because it would take more water to bring the soil moisture back up to the specified level. This is all my best insight into what is happening in your model.
