Link channels

Hi everyone,
Could somebody explain me how properly specify the link channels? I know the idea of them, but I have some problem with visualisation and specifying their parameters. So then, the bed level US is the point of a high bank, the bed level DS is one of the first point of a floodplain. What geometry I specify in cross section geometry?

Thanks in advance.
Mar

Hi Mar,

it's correct that the US level describes the bank's elevation, whereas the DS level describes the floodplain topography.
The cross-section geometry represents a longitudinal profile of the bank, which will be used as a weir between the main stream and the floodplain.

Best regards,
Mathieu

Hi Mathieu,
I have a Question about your response. I appreciate that if you take a look at it.
Are link channels real or just hypothetical means to help us to model flood pains in mike 11?
If water spills from long distance of bank, is it still possible to use link channels or we should use side structures?
cheers.

Hi,
The descriptions you get using a link channel and a (weir) side structure are both approximations of the real world. They both provide the same, i.e. they represent the transversal spilling over the banks using a weir equation. With both options, you can define a storage area in the floodplain, downstream the weir. A difference is that the link channel can be connected downstream to another branch (for example another branch describing the floodplain), but the side structure cannot.

If you have to model a long bank, you may need to use multiple weirs (side structures or link channels) to describe the overspilling, instead of a single one. Using muliple weirs will be more accurate, because each weir will compute the spilling using a local water level in the river bed. On the opposite, if you use a single weir, the spilling will be computed using only 1 water level value, whereas in the real world the water level is usually not constant along the bank.

Best regards,
Mathieu