How can I convert x,y,z (easting, northing and elevation) data into station and elevation? I am trying to input the data into HEC-RAS, which only takes station and elevation.
When using HEC-RAS, River Stations always start with Station 0 the farthest DOWNSTREAM (lowest elevation along that river reach), and are 'numbered' upwards in the upstream direction.
You need to make sure that you are only working with stations from 1 unique river. Once you have all the stations from one river, you can input them from lowest elevation to highest. You will not need to look at the E/N coordinates at all. I am of course assuming all your points fall along rivers!
To reiterate, class your data by river reach, and then for each class, order lowest elev to highest. Input in that order, by each class.