Czechia water: Vodní_plocha, Vodní_tok and the DIBAVOD name join (water_bodies, waterways, water_points) #221

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opened 2026-08-24 17:06:37 +00:00 by art-bot · 0 comments

art-bot commented

2026-08-24 17:06:37 +00:00

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Gated on #212 and #215.

All three water layers come from ZABAGED® polohopis
(https://ags.cuzk.gov.cz/arcgis/services/ZABAGED_POLOHOPIS/MapServer/WFSServer,
anonymous, CC BY 4.0). Counts verified live 2026-08-24.

water_bodies ← Vodní_plocha, 91 667 polygons, with JMENO (name) and
TYP_VP_P (e.g. rybník). Czechia has tens of thousands of fishponds, so the layer
needs a size/type filter argued in the config, not a blanket import — that reasoning goes
next to the query (AGENTS.md).
waterways ← Vodní_tok, 358 804 lines, with idvt (watercourse id),
chp (hydrological basin code), typtoku_p, vydattok_p (permanent/intermittent).
No inline name.
water_points ← Zdroj_podzemních_vod (35 224 springs) and
Vodopád__bod_ (386 waterfalls), plus Vodopád__linie_.

The two things this issue has to establish, not assume

Names for the waterways. idvt is the join key to DIBAVOD / CEVT (VÚV TGM,
dibavod.cz — resolves, not yet fetched). Confirm the licence (R2) and the join
before wiring it. If DIBAVOD is not usable, waterways ship unnamed and that is a written
fact, not a gap left silent.
Strahler connectivity. Vodní_tok is a surveyed network with basin codes, so
connectivity is plausible — and plausible is not verified. Test whether the segments
actually join end-to-end before relying on the Strahler derivation, the way Greece's
waterways issue had to.

Acceptance tests in the same commit, per layer, and the make acceptance tally in the PR.

Gated on #212 and #215. All three water layers come from ZABAGED® polohopis (`https://ags.cuzk.gov.cz/arcgis/services/ZABAGED_POLOHOPIS/MapServer/WFSServer`, anonymous, CC BY 4.0). Counts verified live 2026-08-24. - **`water_bodies`** ← `Vodní_plocha`, **91 667** polygons, with **`JMENO`** (name) and `TYP_VP_P` (e.g. `rybník`). Czechia has tens of thousands of fishponds, so the layer needs a size/type filter argued in the config, not a blanket import — that reasoning goes next to the query (AGENTS.md). - **`waterways`** ← `Vodní_tok`, **358 804** lines, with `idvt` (watercourse id), `chp` (hydrological basin code), `typtoku_p`, `vydattok_p` (permanent/intermittent). **No inline name.** - **`water_points`** ← `Zdroj_podzemních_vod` (**35 224** springs) and `Vodopád__bod_` (**386** waterfalls), plus `Vodopád__linie_`. ## The two things this issue has to establish, not assume 1. **Names for the waterways.** `idvt` is the join key to **DIBAVOD / CEVT** (VÚV TGM, `dibavod.cz` — resolves, not yet fetched). Confirm the licence (R2) and the join before wiring it. If DIBAVOD is not usable, waterways ship unnamed and that is a written fact, not a gap left silent. 2. **Strahler connectivity.** `Vodní_tok` is a surveyed network with basin codes, so connectivity is *plausible* — and plausible is not verified. Test whether the segments actually join end-to-end before relying on the Strahler derivation, the way Greece's waterways issue had to. Acceptance tests in the same commit, per layer, and the `make acceptance` tally in the PR.

art-bot self-assigned this

2026-08-24 17:06:37 +00:00

art-bot referenced this issue

2026-08-24 17:18:38 +00:00

Catalogue Norway, Denmark, Czechia and Slovakia — the add-country go/no-go gate for four countries #238