Jump to content

Recommended Posts


In ESTRY is it possible to apply a QH rating in the channel. Not as a downstream boundary, but in the middle of a reach to act as a control representing a structure in the channel? 


In regards to QH ratings in channels, there are two different methods:
•    M Channel (section 5.8.1 of the 2016 Manual)
The M channel uses a matrix of QH relationships to define the mechanics. You can also read the description in the manual but I’ve coloured up my example csv for easy reading below. There are a few rules with the flow values: the matrix must be square, it must have the centre line of diagonals and it must be negative (or zero) below the diagonal and positive (or zero) above.
•    Q Channel (Section 5.8.2 of the 2016 Manual)
This uses a Depth Discharge curve, like you would for a pit inlet. The H values in this case are for the upstream end of the culvert.

In deciding between the two of them, I’d have a look at the culvert and the flow regimes you expect. If you think that the culvert will have significant downstream control, then an M channel is the better option. If it’s pretty much always upstream controlled, then you may be able to get away with just a Q channel.


Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...