Mike 11 reservoirs and spillways

Hi all,

I am trying to represent an reservoir, dam and spillway that are located along a river.  Essentially I have a  storage elevation relationship for reservoir (no cross sections) and a Qh relationship for the spillway.

Currently I am using the Regulating Structures, and the "Additional Storage Area" option in the Mike 11 cross section to represent the storage, but I feel that there may be a better way.

One of the problems is that I do not have cross sections of the reservoir so the only way I was aware of to represent the storage is to use the "Additional Storage Area" option.  Any other ideas?

Regards

Jon

Hi Jon,

Sounds like you've got the right approach there. Be aware that by schematising the reservoir as additional area then you wont represent the attenuation of flood waves through the reservior. I'm not sure if that is important to have included in your model. If it is, then you may want to think about formulating some cross sections that preserve as much as possible the area-elevation realtionship while allowing you to represent the 'length' of the reservoir.

Cheers, Colin.

Hello everyone,

I have to introduce a reservoir in a model type Mike 11 and also the operation rules of the control structures.

The question is: which structures should I use?

I tried to make use of "Control Str." from Notwork file -> Structures, and I chosen "Side structure + reservoir" as Structure Type, "Overflow" as Gate Type and set up all the necessary parameters. The result was that almost all amount of water went downstream the structure and a little amount of water went in my reservoir. This seems more like a control structure for a polder or an effective side structure.

I also tried  to combine a "Control Str." structure with a "Weir" structure, in order to obtain an ineffective flow area, but it didn't worked at all!

I ask you, because i didn't find something on the internet regarding how to model a reservoir in Mike 11 neither a simple example(which would be very very useful). DHI provides only the user manual for this topic, and I think that is not enough.

Regards,
Aurelian

Hello Aurelian

Modelling reservoirs in Mike 11 is an unresolved problem to a lot of modellers. I also tried to find a way to introduce a reservoir to a canal network. Ultimately I have decided to input cross sections to represent the reservoir and a weir(Regular type) to control the flow. I think this is not a good approach but I have to do as lack of explanations.
In your case you should understand difference between each type of structures (i.e. Regular, Side Structure and Side Structure+ Reservoir). My understand is, Regular means, across the main river. If you define a structure as Regular, then downstream flow will be affected significantly due to the structure. Also, if you define a structure as Side Structure type, then the flow of your main river will not be obstructed as a function of your structure.
I think this information might useful to you.

Thanks

Hi ransara,

Thank you for your answer. I chosen "Side structure + reservoir" because only this type of structure allows you to introduce the storage curve of the reservoir.

As I said, a simple example of how to model a dam with a reservoir and its operational rules would be priceless.

Have a nice day,
Aurelian

Hello Aurelian

Side + Reservoir function as the attachment. This is my understand. You can do experiments.

Hello ransara,

Thank you for your effort. I understand that the structure type "Side structure + reservoir" is not an option if you want to model a dam and its reservoir, because this is a frontal structure and not a side structure.

Thank you again,
Aurelian

Hi
I can run dam break in Mike 11.
But it does not looke like breaking  to down stream.
Anybody run successfully ? Want to know tip.

Thank

Hi all
To represent a reservoir online , you need to cross section which represent the your elevation and storage volume. End of reservoir you can create a control structure and weir for spillway.
Side structure is for off line storage (used for detention pond). That same as add-storeage area in cross section (to estimate the pond volume to minimize the flood water level). Side structure with reservoir is simalar to side structure. We can not inseret other structure to dischare from storage.

Goood Luck

Dear all,
I would like to insert a structure (dam) with my own Q-H table in the easiest way possible. I am trying to use the “Special Weir” but there is a lot of columns that needs data, for example H-pos, H-weir, Width, Area and so on. Anyone who can help me?   

Best regards Martin

hello everyone,
I have simulated dam break in MIKE11 with PMF flood. As the spillway has designed for PMF flood, it should not break due to simulation period but in my model the dam breaks. Obviously it is wrong and I can not understand which part it refers.But I guess it is related to the reservoir volume that may have some approximation.
does anybody know how can I find the reservoir volume and compare that with its real value?
I appreciate you if respond as soon as possible.
regards,
Eli

Hi,

the easiest way to check the reservoir's volume is to save the water volume in the result file.
This is done in the HD11 file, by ticking the item "Volume" in the "Add. Output" tab.

After doing this, MIKE 11 will store this item in the additional result file. You will hence get access to the instantaneous water volume in each calculation point. So you can easily check, for a given water level, the volume in your reservoir. Keep in mind that, if you have several calculation points to describe the reservoir, you then have to sum the volumes from these points.

Mathieu

Hi,

Could you tell me what's the difference between Volume [b]H or Q point[/b] and [b]Total[/b]? Because when I'm ticking both items and then I'm checking the value (sum of volume in points and total volume), they're differing. I'd like to know of the reasons impact the result and the difference between each other.

I'll be deeply grateful for explanations.

Kind regards,
Mar