Barrage or weir in reach

[Howard van Meer]

Dear members,

 

In recent months I have finally decided to move to SWAT+ and I asked the same question in regular SWAT group like 2 years ago. We have a barrage/weir from which water is diverted for irrigation, the rest goes downstream and follows its path to catchment outlet. The discharge is not constant and we possess daily discharge data for water that is diverted from the reach and is being allocated for irrigation. Most of the irrigation area falls outside our catchment.  Does anybody know how to put this  in the model? Irrigation can only be modelled as being constant throughout time from January to December in the management table. Does SWAT+ offers the possibility to attach a discharge file for the amount of water that is being allocated for irrigation for a 30 year timespan and varies daily? It is not a reservoir, just a barrage that works as an inlet to the main irrigation channel by raising reach´s water level. Ik think it is a missed opportunity not be able to add some table with daily water extraction from main stream for irrigation purposes since in most semiarid regions extraction for irrigation poses a substantial amount of .water "lost" every day. 

Kind regards, 

 

M.Sc. Ing. Howard van Meer 

INTA Santiago del Estero

Agrometeorología, modelaje climático hidrológico y uso agrícola del agua

Agrometeorology, hydrological climate modelling and agricultural water management

Jujuy 850

G4200CQR Santiago del Estero, Argentina

Tel. +54 (0)385 4224430 Int. 135 (fijo/fixed)

Tel. +54 9 (0)11 (15)68939791 (Cel.)

[Natalja C.]

Hello,

Let me clarify: your irrigation gets allocated from outside the watershed and diverted also outside of the catchment? If yes, then you should "add" the water as point source and then "remove" this water from your model for consumptive use. But I think I misunderstand... seems like a loop :D

I did not explore this option in swat+. In swat2012 there was a water withdrawal option, so I expect the same in swat+. SWAT+ is more more flexible in allocating water, therefore I think you made a correct decision to transition.

If you can, make a visual map of what is going on and what you want to model. :)

Cheers,

Natalja

[Howard van Meer]

Natalja thank you for responding on such a short notice. Water is allocated from inside the catchment to outside the catchment (most the irrigation area is situated outside the catchment). Coordinates  for intake is S -27,651861 and W -64,362459. I added an image to clarify some things. We have 30 year daily data for this intake. This water is extracted from our catchment area (total area of 69000 km2). This channel has a maximum capacity of around 90 m3/s. Sometimes this amount is around 40% of discharge through the main river so you can understand the importance of getting this thing right. 

Howard

Op wo 31 mrt. 2021 om 07:31 schreef Natalja C. <natalja....@gmail.com>:

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