fix(wateren): refine island inlet connections for Noordzee polygon #38

New issue

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opened 2026-04-09 08:06:32 +02:00 by Ghost · 1 comment

Ghost commented

2026-04-09 08:06:32 +02:00

(Migrated from codeberg.org)

Context

The Noordzee polygon was rebuilt in v1.14.1 using the upper-hull outer (N-facing) coasts of the 5 Wadden Islands. This eliminated the long diagonal line from Den Helder to Schiermonnikoog through the Wadden Sea.

Minor flaws to address

The current implementation uses convex upper-hull points per island, which creates straight-line jumps across the inlets between adjacent islands:

Texel → Vlieland (Eierlandse Gat): transition gap could be smoother
Ameland → Schiermonnikoog (Pinkegat / Zoutkamperlaag): visible step in the N coast

These are cosmetic — no line crosses the inner Wadden Sea — but the N boundary of the Noordzee polygon looks slightly angular at the inter-island inlets.

Possible fix

Replace the per-island convex hull with actual chained OSM coastline ways for the outer (N-facing) coasts, applying a tighter lat-filter per island to exclude the inner (S-facing) wadden coast. The chained outer coasts would follow the real beach/dune geometry and produce smoother inlet transitions.

## Context The Noordzee polygon was rebuilt in v1.14.1 using the upper-hull outer (N-facing) coasts of the 5 Wadden Islands. This eliminated the long diagonal line from Den Helder to Schiermonnikoog through the Wadden Sea. ## Minor flaws to address The current implementation uses convex upper-hull points per island, which creates straight-line jumps across the inlets between adjacent islands: - **Texel → Vlieland** (Eierlandse Gat): transition gap could be smoother - **Ameland → Schiermonnikoog** (Pinkegat / Zoutkamperlaag): visible step in the N coast These are cosmetic — no line crosses the inner Wadden Sea — but the N boundary of the Noordzee polygon looks slightly angular at the inter-island inlets. ## Possible fix Replace the per-island convex hull with actual chained OSM coastline ways for the outer (N-facing) coasts, applying a tighter lat-filter per island to exclude the inner (S-facing) wadden coast. The chained outer coasts would follow the real beach/dune geometry and produce smoother inlet transitions.

Ghost commented

2026-04-19 18:53:01 +02:00

(Migrated from codeberg.org)

Fixed in v2.7.2