Hello fellow mappers, I am reaching out for advice on the most efficient way to map a complicated coastline, sabkha, erg system on the Sealine Peninsula region of Qatar. For reference, the area is located here: Qatar - Sealine Peninsula
Previous mapping was a form of abstract art aspiring to the level of detail present in Minecraft so what I’ve been able to accomplish so far is a major improvement. However, I am running into some limitations unforeseen and I’d like a do over but with a better action plan than last time.
A brief description of the area to set the tone. The peninsula is a low-lying, low relief area dominated by broad flat areas often inundated by tides. Vegetation is sparse, there are some tidal channels and tidal inlets and a very small number of elevated rocky outcrops and old oyster beds. The other major feature(s) are large barchan sand dunes that migrate in a NW-SE direction. In spots, the dunes give way to mini basins of the sabkha. Nearer the shoreline these mini basins can become inundated with seawater. The edge of the sabkha is defined by a transition to rocky terrain that has a slight elevation. From the sat images you can see the rocky area as a brighter background, the sabkha is darker and the dunes are lighter colored.
My previous mapping started with trying to outline the larger dune systems, fill in the mini basins as a multi-polygon relationship and connect either the sabkha or sand to the shoreline where they met. It started getting complicated when I tried mapping isolated dunes alone on the sabkha or if the sabkha had a tortuous connection around and between dune systems. In a few spots I found my mapping had resulted in a shared boundary of dune systems and even one “triple junction” which has given me fits ever since. The unforeseen limitation I ran into was connecting individual nodes of the interior sabkha mini basins to the erg systems and reaching a limit beyond which it would not allow any more connections.
My idea, goal and what I am asking for help with: I was going to delete the individual larger sabkha sections and remap them to be the unified single foundation that ties the area between the rocky edge of high ground and the shoreline. Then, use multi-polygon relationships to carve out the ergs (sand dune systems and individual dunes) from that foundation. I’d like to avoid having to remap all the “donut holes” and try connecting the existing mapped larger sabkhas into one continuous area without deleting and remapping everything. My goal is to have a single, unified sabkha, mapped ergs and dunes carving out areas where they are present and keep as much of the original mapping as possible but cutting/merging areas back into that single entity.
Help is requested on validating the approach, advice on how to better proceed rather than brute force mapping everything again and any pitfalls to avoid as I embark on this quest. Or, is what I have done already about as good as it can get and the few areas where the connection limit has been reached are acceptable artifacts?
Who cares? Yeah, I know these areas are dynamic and the sand is literally shifting all the time. However, the area is remarkably stable, especially the larger dunes and where I have mapped the edges and ridges are extremely useful in navigating the area while in a 4WD or fat bike. If you turn on the GPS traces you’ll see the area is well trodden.
Thanks in advance for any help you can provide.