Need Help Making Assembly for Stream Channel Design
We have a project realigning over a 1/2 mile length of stream channel and have several questions in trying to determine the best approach for drawing the channel. We believe the best approach would be to use corridors, but there seems to be several issues in this strategy. Please note, I am familiar with several components of C3D (i.e. surfaces, feature lines, grading groups, alignments, profiles), but am new to using corridors. Any input/assistance provided is greatly appreciated - Please ask if more information is needed as I don't want to confuse others with too much upfront.
We used natural channel geomorphology principles to design our channel. This means that we have riffles (think of these as check dams spaced at specified intervals) and pools (the low areas between the check dams). Furthermore, the pools are placed at each of the bends so that they are closer to the outside of the bend, thereby no longer centered between the top of bank on the left and right side (See attachment figure1). This deepest area where the water most frequently travels is called the thalweg. I have attached 4 figures showing examples of what we have to work with:
1) typical sections of the channel (dimensions shown are for this question only, our actual channel is larger),
2) snapshot of our stream centerline alignment with tops of bank offset from the centerline,
3) a snapshot of the profile (red dashed line at top = existing grade, green = top of incised floodplain, yellow = approximate low flow water surface elevation, and magenta = bottom of channel at the thalweg); and
4) assemblies created for the riffles and pools using generic subs.
Our first question/problem: Is it possible to create an assembly using a horizontal link set at the bottom of the channel and follows the thalweg profile (magenta), and two horizontal links set to follow the incised floodplain profile (green), then connect these together with a link that has a variable slope and length?
Second question/problem: Is there a subassembly that allows the horizontal links widths to be set at specified stations? Based on the research I have done it looks like this could be done possibly by either creating more assemblies and connect them with transitions or by using different targets - both of which I am not familiar with.
I look forward to reading the responses!
Reply With Quote