I have delineated a river centreline and interpolated the Z values from a DEM (SRTM 90m) to generate a 3D polyline that represents the river centreline. I have then adjusted the Z values within the 3D river centreline and increased it by 20m and 40m respectively. I've tried to use Visibility Analysis tool to try to generate the floodplain, but the results aren't great even after adjusting the vertical, horizontal and radius parameters. Any alternative would appreciated.
So as explained, I'm trying to delineate the expected inundated surface areas coarsely from the river centreline, based on an adjusted Z value, then trying to determine the horizontal impact area of the DEM that is covered by water.
Regards
