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Topic: Interpolation and Intersection of 2d cross section and elevation line
Replies: 1   Last Post: Apr 24, 2013 12:29 AM

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 Derek Goring Posts: 3,922 Registered: 12/7/04
Re: Interpolation and Intersection of 2d cross section and elevation line
Posted: Apr 24, 2013 12:29 AM

On Wednesday, April 24, 2013 10:34:09 AM UTC+12, Becky Rittenburg wrote:
> I am having trouble figuring out the best interpolation method to use with my data. I have stream profile cross sectional data in the form of positional (x) and elevational (y) discrete points, which were not taken at consistent intervals. What I'd like to do is determine the cross sectional area at different velocities of "flow" through the cross section. To begin, I'd like to interpolate the original position and elevation data so that I can find the intersection points on the left and right bank at a given elevation, create a line at these points, and determine the area beneath the line.
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> If you have any pointers, I'd greatly appreciate it. Thanks!

I've done this, not with river cross sections, but with beach profiles.
I found the best way is to split your domain into vertical strips from each survey point up to the maximum RL (reduced level) - in my case, I did it the other way, down to Chart Datum.
Now, for a set of vertical intervals, you can loop across the vertical strips, doing calculations on each strip, then assembling the results into matrices.
The details are trivial.

Date Subject Author
4/23/13 Becky Rittenburg
4/24/13 Derek Goring