I have polygon dataset containing quite a complicated coastline. How can I produce an outline of that coastline?
Please see the image: my dataset is in green and the coastline I need to get is in red.
The line does a pretty good job of mimicing your hand-drawn line. The smaller the concave hull parameter, the tighter the line sticks to the coastline.
The other red line, running round the back, is the rest of the polygon generalised. You won't get this if you are working on a complete set of east coast polygons, or you could clip it out later.
This was all done using QGIS and built-in processing functions.