I'm attempting to determine the 2D area beneath around 3,000 polyline features as in the diagram below:
(Polyline feature stretches from upflow to downflow end)
I have a DEM representing a flat surface (the base of the feature) and another containing the relief of the feature, the part I'm interested in is the two-dimensional area beneath the curve. I'm not too sure how to determine this parameter, does anybody have any ideas on this?
I'm using ArcGIS 10.4.1 and all extensions are available.
If I have understood your question, your polylines describe the curves whose area you want to know and the start and end points coincide with the flat base. If so, you can convert the lines to polygons and then get their 3D area, which is an attribute of their geometry and automatically calculated.
To close the lines to make polygons, will take a little work. It can be achieved by scripting (if you have any Python experience) by iterating over the points and adding one extra point in each case that is identical to the start of the line. Alternatively you can use ETGeoWizards close gaps (but I don't think that is a free tool). Once you have closed lines, you can use the Feature to Polygon tool to make the polygons.
Possibly the simplest way of closing your lines is to ensure each line has a unique ID (if it doesn't, create a new field and use the row number). Then convert the lines to 3D points and then convert the points to polygons.
