ArcGIS lines to polygons without holes

Question

I have a dataset with contours. Depression contours are separate of the normal contours and need to be digitized counter-clockwise. Still, there are usually some faulty ones with wrong direction and manually going through thousands of them is painful. I learned that it is possible to convert the contour lines to polygons and back to lines again since arcgis polygons outer edge is always digitized clock-wise - then I just reversed all the lines. Unfortunately, if I have several contours inside each other it creates polygons with holes and hole edge is always digitized counter-clockwise. Now if I convert the polygons to lines and reverse them all the holes are with wrong direction.

Is there a way to create polygons of each closed contourline without it creating a hole if there is a smaller contour inside? Or is there a possibility to somehow differentiate between lines that are the outer edge of the polygon and which have been the hole edge so I can only switch the direction of the outer ones?

Or maybe there is an even simpler solution in finding depression contours that are digitized in clock-wise movement and only flip them around?

If it can be done in some other software that keeps the elevation data, you can suggest that also.

Answer 1

With ArcGIS for Desktop Advanced, you could

• Convert all depression lines vertices to points (with Feature Vertices to Points)
• Convert all vertices back to lines (with Points to Line, with the Close Line option checked)
• Revert the direction of all lines (with Flip Line).

Answer 2

If GISGe's solution works, I'd go for it. Nevertheless, if you still need a solution to remove the holes from polygons, you can just run the union tool and unselect the "gaps allowed" checkbox.