French dude, Clément Molin works on mapping tranches, both Russian and Ukrainian, for 2 years now.
The Finnish map: https://www.scribblemaps.com/maps/view/The%20War%20in%20Ukraine/091194 still only shows the Russians.
Here's Clement's posts on twitter:
https://twitter.com/clement_molin/status/1745033008938102852
I only found an onion link for nitter instance that worked. The rest I found dead.
http://nitter.esmail5pdn24shtvieloeedh7ehz3nrwcdivnfhfcedl7gf4kwddhkqd.onion/clement_molin/status/1745033008938102852
He also has a google map, he updates:
https://www.google.com/maps/d/viewer?mid=1HGTwN8Nx6vsl3n8UnsmZnFhonE_ziAU
I wish he used something else than google.
Clément, thank you for your work.

One thing have to note. Mostly he can map only those trenches which can be seen from satellite imagery. So those in forests and towns and underground tunnels he can miss. He ofc notes, his map isn't exhaustive. I think themap is extremely blind in cases such as Bakhmut and Avdiivka. I heard several times now in relation to Avdiivka, that there were no defenses. I assume this why it could hold out for so long, right...?
From the images and his explanation these fortifications very much based on the same idea that was the foundation of the Árpád-line ( C3%81rp%C3%A1d_Line">https://en.wikipedia.org/wikiC3%81rp%C3%A1d_Line ). The defensive line consists of independent strongpoints, where circular defense is possible (towards every direction), and can offer fire support for each other.


I'll dump some of his stuff from twitter.