fluctuated graphs

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bahri
Senior Member
Posts: 61
Joined: Wed May 11, 2016 4:43 am
Vensim version: DSS

fluctuated graphs

Post by bahri »

Dear,

Let's suppose I have 2 stocks as follows:

Carrascal Ferrer Aquifer1= INTEG (infiltration after precipitation to Carrascal Ferrer+seepage from surface water to the Carrascal Ferrer aquifer
-Carrascal Ferrer aquifer extraction -monthly spring and upwelling flow, initial Carrascal Ferrer aquifer volume)
Units: hm*hm*hm

Carrascal Ferrer Aquifer2= INTEG (infiltration after precipitation to Carrascal Ferrer+seepage from surface water to the Carrascal Ferrer aquifer
-Carrascal Ferrer aquifer extraction, initial Carrascal Ferrer aquifer volume)
Units: hm*hm*hm

The main difference between Carrascal Ferrer Aquifer1 and Carrascal Ferrer Aquifer2 is Carrascal Ferrer Aquifer2 is without a flow named
monthly spring and upwelling flow.

After simulation, I found that Carrascal Ferrer Aquifer2 is more fluctuated than that Carrascal Ferrer Aquifer1?
Can someone please explain this issue ?
tomfid
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Joined: Wed May 24, 2006 4:54 am

Re: fluctuated graphs

Post by tomfid »

The superficial answer is that the difference must be due to the additional flow. Without a working copy of the model, it's impossible for anyone to say more. Can you post the model?
bahri
Senior Member
Posts: 61
Joined: Wed May 11, 2016 4:43 am
Vensim version: DSS

Re: fluctuated graphs

Post by bahri »

Dear,

I attach the model.

Please use fraction of spring and upwelling flow to
set monthly spring and upwelling flow

Cheers,
Bahri
Attachments
carrascal_ferrer_forum.mdl
this is a vensim model
(45.32 KiB) Downloaded 182 times
tomfid
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Re: fluctuated graphs

Post by tomfid »

The behavior looks OK to me. There's less water in the aquifer at the end of the run with upwelling, due to the cumulative loss from that constant outflow.
bahri
Senior Member
Posts: 61
Joined: Wed May 11, 2016 4:43 am
Vensim version: DSS

Re: fluctuated graphs

Post by bahri »

Dear,

What do you mean cumulative loss of constant flow (monthly spring and upwelling flow)?
Could you please be more specific ?
As far I understand, cumulative is only for stocks and not for flow such as monthly spring and upwelling flow.
tomfid
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Joined: Wed May 24, 2006 4:54 am

Re: fluctuated graphs

Post by tomfid »

Correct - what I mean is that the stock is lower at the end because it has accumulated the loss from the outflow.

The flow is 2/3 hm^3/month, for 72 months, and the difference is about 48 hm^3, i.e. 2/3*72.
bahri
Senior Member
Posts: 61
Joined: Wed May 11, 2016 4:43 am
Vensim version: DSS

Re: fluctuated graphs

Post by bahri »

Thanks a lots,
How do you get 48 hm^3?
Because I got 47.3 hm^3, not 48hm^3
tomfid
Administrator
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Re: fluctuated graphs

Post by tomfid »

I rounded off. But you also have only 71 months.
bahri
Senior Member
Posts: 61
Joined: Wed May 11, 2016 4:43 am
Vensim version: DSS

Re: fluctuated graphs

Post by bahri »

Ok, thanks.

I attach a revised Vensim model.
Please open and go to Control Panel and open a graph name "historical and simulated volume of Algar aquifer".
The graph shows two lines "Carrascal Ferrer aquifer" and "historical volume of Carrascal Ferrer aquifer".

"Carrascal Ferrer aquifer" is simulated volume and "historical volume of Carrascal Ferrer aquifer" is "observed volume".

Can you please suggestion/advice how to make simulated one reproduce a similar pattern of observed one?.
Especially using "any delay functions" and any other possible functions?
Any advice will highly be appreciated.
Attachments
carrascal_ferrer_forum_sent.mdl
a revised Vensim model
(44.42 KiB) Downloaded 176 times
tomfid
Administrator
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Re: fluctuated graphs

Post by tomfid »

We would need the dataset (vdf) to view.
bahri
Senior Member
Posts: 61
Joined: Wed May 11, 2016 4:43 am
Vensim version: DSS

Re: fluctuated graphs

Post by bahri »

Hi again,

For calibration process, we can insert constants in the calibration process (optimization setup).
can we insert lookup variables in the optimization setup ?
tomfid
Administrator
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Joined: Wed May 24, 2006 4:54 am

Re: fluctuated graphs

Post by tomfid »

No, but you can use VECTOR LOOKUP on an array of constants.
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