A flood wave travelling down the Danube

February 2026: one flood wave, five gauges, ~320 river-kilometres. Daily mean water level at each gauge, upstream to downstream — the crest passes Komárom on 25 Feb and reaches Mohács three days later. Public OVF data retrieved by an AI agent through ovf-data-mcp. Operational data — preliminary, unchecked.

Daily mean water level, 1 Feb – 24 Mar 2026 (cm, local gauge zero)

One panel per gauge, upstream → downstream · y-scales differ (each gauge has its own datum) · hover or focus + arrow keys for values

Data table — daily means, all five gauges

How this page was made

An agent resolved five gauges along the Duna, then ran one bounded server-side aggregation per gauge:

vizugy stations search "" --watercourse Duna --limit 100
vizugy observations aggregate surface:5 --start 2026-02-01T00:00:00Z \
    --end 2026-03-25T00:00:00Z --interval daily --operation avg   # × 5 gauges

These commands are the only data source. The agent then merged the JSON responses and wrote this page’s HTML, CSS, and JavaScript itself — no chart libraries, no build step.

Source: Országos Vízügyi Főigazgatóság (OVF) via the public VRAQuery API · metric “Felszíni vízállás” (surface water level, cm), data type “operatív összefésült” · retrieved 2026-07-18 10:37 (UTC). Levels are relative to each gauge’s local zero and are not comparable across gauges; river-km positions are approximate. Aggregation buckets follow upstream hydrological-day boundaries. Operational values may be preliminary; for checked data follow OVF’s formal data-request process.