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All Topics | Topic "Simulated storage volumes larger than observed storage volumes"
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Ms. Victoria Iyambo

Subject: Simulated storage volumes larger than observed storage volumes   
Posted: 6/12/2021 Viewed: 4353 times
Hello all,

I am doing a study on water resource management and I am calibrating my study area with reservoir storage volumes. I have River head flows data that are higher than the reservoir storage (full supply capacity, FSC) and the demands downstream. In reality, The releases (outflows) are made to keep the reservoir below 100% of FSC through the reservoir gates, hence the observed volumes are lower than FSC regardless of higher inflows. I have the outflows data, which I have input into the maximum hydraulic outflows but it doesn't make any changes since WEAP is assuming the reservoir is spilling due to higher inflows. The results are then showing higher simulated storage volumes compares to observed volumes with a huge gap in between. I have tried to create a diversion link with the outflows data but still, it doesn't make any difference.

How can I go about it to get my simulated storage volumes closer to the observed storage volumes in order to have good calibration results?


Ms. Anne Hereford

Subject: Re: Simulated storage volumes larger than observed storage volumes   
Posted: 7/8/2021 Viewed: 4245 times
Dear Victoria,
There might be a simpler way to do this but could you use the outflow data to create a Flow Requirement node immediately downstream of the reservoir? This would force the release of the volumes recorded in your outflow data. Do you have a Top of Conservation defined that is lower than the Total Storage Volume?

Ms. Victoria Iyambo

Subject: Re: Simulated storage volumes larger than observed storage volumes   
Posted: 7/14/2021 Viewed: 4214 times
Thank you very much Anne,

I have resolved the issue by setting the Maximum Hydraulic outflows to default (0) and then my demands (annual activity rate) were monthly while WEAP requires only annual demands. The flow requirement didn't work, hence no outflows were input into the model. I compared the simulated outflows with the observed and it gave the best satisfactory fit.

The calibration looks better now, except overestimating when there are higher inflows.


Topic "Simulated storage volumes larger than observed storage volumes"