Catalogue des vallées des Pyrénées — an atlas for exploring the Pyrenees one valley at a time, built from open topographic and hydrographic data.
The Pyrenees are not a flat map — they're a highly folded territory made of hundreds of valleys, each a small world of its own. Two valleys that look close as the crow flies can be a full day's drive apart by road, separated by a ridge. There's no natural "next" or "nearby" between them — only the river network that drains them, and the mountain passes that occasionally connect them.
valleespyr treats rivers, not roads or grid tiles, as the map's spine. Every named watercourse in the range is a node in one big tree, rooted at the Garonne. Browsing the tree — trunk to tributary, tributary to headwater — is the way to move through the mountains: pick a valley, see where it sits in its river system, drop into a 3D view of its terrain, then climb back down and branch off into the next one.
The result ships as one static, self-contained webpage: no backend, no database, no login — open the page and start exploring.
A two-level drainage-tree selector: the trunk river runs down the left as a lane, tributaries branch off it (visually not unlike a commit graph), and picking one re-centers the view one level down. Next to it, a map traces the selected valley's course and catchment; picking a valley with a baked terrain model swaps that map for an interactive 3D relief block — heightmap, draped stream network, and a real IGN aerial/topo texture — built from open elevation and map data.
IGN's BD TOPO stream-segment layer is rolled up into a graph of whole rivers ("flows into" edges), which gives the browsable tree and each valley's catchment network for free. Where IGN's own watershed layer doesn't cover a river, its drainage basin is delineated instead from a Copernicus GLO-30 elevation model. Everything — the tree, the maps, the 3D terrain blocks — is precomputed offline into static JSON/HTML and published as a GitHub Pages site with no server component.
See app_requirements.md for what the app does and its UI, and app_design.md for the technical choices, data sources, and algorithms behind it.
This repository is being rebuilt from scratch around the minimal scope captured in those two documents, after an earlier, messier exploration phase established what was worth keeping: the river-graph catalog, the DEM catchment pipeline, and the 3D terrain view.