Contour Lines from Polygon

Question

Hello everyone,

I have a dataset showing groundwater tables as polygons. The attribute table contains a column with a range of water levels (for example "30.5 m - 31.0 m").

I am trying to label  the contours with the water level at their respective isolines. So far I only created columns containing the lower and upper bounds but I am lost when it comes to label placement.

Does anyone know how to accomplish this? Any help would be appreciated.

Maps-Berlin · Answer

Thanks for the Help,

unfortunately I wasn't able to execute your guidance successfully. A new problem arose with intersecting waterways. The Polygons are cut at waterways which causes lines of different elevation levels to be drawn as a single feature.

I will revisit again in the future but after having spend a good amount on hours yesterday and today on this I will be giving up for now.

DavidPike · Answer

It's disappointing the tool doesn't transfer attributes, but these can be restored with a table join afterwards if 'identify and store polygon neighbour information' is unchecked.

yes, 2 overlapping lines should be created if the checkbox is unticked. You can approach it wither way by retaining the neighbour information, but I think this is a more understandable workflow.

Spatial Join - Join the lines to themselves and each will get the height attributes of the intersecting line.

Afterwards field calculate a new field showing the values of both heights e.g !HOEHE! + ", " + "!HOEHE_1"

then run a new field calculation to return the highest value from the lowest range.

export as new features without the join field and delete identical.

Maps-Berlin · Answer

Hey, thanks for taking a look at this.

I tried the conversion to lines but this resulted in loss of the elevation attributes. But even if I managed to keep those, since right now each contour line consists of the outlines of two polygons, wouldn't the conversion to lines result in 2 overlapping lines each containing different elevation values?

What I am trying to achieve is a regular contour map with values written on contour lines like this:

what I have is this: