Hi -- I need to combine USGS National Hydrologic Data Flowlines and land surface altitude data for a groundwater modeling application. Don't know where to start, anyone have any ideas? Thanks.
Bruce, Are you looking for 3d lines or points along the lines with elevations in an attribute field?
If you want 3d lines, use Feature to 3d(I think this was added in 10 or 10.1 so hopefully your version of arc supports it): 1. Customize Menu->Toolbars->Customize...->Commands Tab->search for Feature to 3d(requires 3d analyst) 2. Input Features=NHD layer, Set the height source to your elevation data(DEM or TIN), Save it where ever you want
This will create a polylineZ file with elevations stored within the line to make it a 3d shape.
If you want points with elevations(requires DEM elevation data and spatial analyst): 1. Convert your lines to points with your preferred process. I like EZprofiler because i can set the distance between points easily(free here: http://arcscripts.esri.com/details.asp?dbid=16031) 2. Spatial Analyst Tools->Extraction->Extract Values to Points
This will attribute your point file with the elevations at each location.
