Hi,

I have a polygon outline of the a river system with no elevation. Using contour shapefile, I generate a DEM raster, then drape the river polygon to get elevations for each point in the polygon.

Problem I have is the data does not match. Occasionally the river edge covers the coastline so there is a slope across the river from one side of the river to its opposing side.

Example being, if I stand on one side of the river and look to the other side, whilst being perpindicular, both z values should be the same. However, my results aren't the case.

I've tried raster coercer to do some averages of z values and using neighbour finding to assign z values on the polygon, however when the neighbour is 'inbetween' points, it becomes inconsistent.

is there a way to get clean centrelines without having the 'spider' legs along the way?

Is there a way to draw perpendicular lines at each point of the polygon? Then I can use it to cut up the polygon to small segments. Use the segments and clip to raster coerced cells, sort, and sample the lowest value. Connect the points, buffer the line, and finally drape the river polygon.

Thanks.