1 How big is the flood?Rare
🌧 Build your own rain scenario
Build this flood Back to mapped sizes
Rain reaching the river = rain × duration × (1 − soaked up) × (1 − drained), compared with 37 years of real 48-hour rain in the catchment of the area to find its yearly chance; the flood map for that chance is interpolated between the EFAS maps. A simple index, not a hydrological model: short storms on small streams, snowmelt and blocked bridges are not represented.
2 Press ▶ under the mapWater rises upstream first. Pause (space) and click the map to check a place.
Right now
– people live in flooded areas
– buildings in the water
– km² under water
Model or real 2021?
Model July 2021 satellite Both
Safety zones
Based on all flood sizes together, not only the one you picked.
Shelters
Chosen from real schools, sports halls and community centres (overnight shelters) and stadiums and parks (assembly points only). Must be dry in every flood size, not flooded in 2021, at least 150 m from flood water. Ranked with equal weight on: at-risk residents within 1.5 km, capacity, height above flood water, distance to water; no dry road access halves the score. Capacity = floor area × floors ÷ 3.5 m² per person (Sphere minimum); type your own number to override. Check kitchens, toilets, accessibility and the building owner on site.
Critical sites in the water
Hospitals, clinics, fire stations, police, town halls flooded in this flood size: evacuate or protect them first.
Safe route A → B
Clear A–B
A → nearest shelter
By car On foot
Double-click the map : first A, then B. The route uses real roads and avoids the water at the moment shown in the video (try "water rising").
Drill: people, shelters, best actions
How people really move over the event: some stay home, shelters fill up, streets flood. Press Training mode under the map to take the decisions yourself; the controls under the map change the scenario.
Forecast: which plan?
July 2021 replay Live forecast
Load Save
Rain and river flow from Open-Meteo (external source: GloFAS river model ~5 km, ERA5 / forecast models). A small river like the Vesdre is only roughly captured: check the official river gauges (SPW hydrometry) before acting.
Emergency teams: who goes where
Real fire stations, police stations and hospitals send teams to flooded hospitals and key sites, and to residents who cannot reach a shelter in time. Teams drive on roads that are passable at the moment shown in the video: pause at "water rising" or at the peak, then dispatch.
Nearest first Priority first
Dispatch now
Team assumptions
Priority: hospitals and clinics first, then fire, police and town halls in the water, then groups of residents (more people and earlier waves first). Team numbers, speed and time on scene are assumptions: replace them with the real figures of the emergency zone.
Be ready before the water comes
Agree in advance which plan starts when a river forecast says a flood size is likely. Figures come from the flood maps and the plan in Evacuate.
What to do: 30-second video
Share with emergency services
Situation report (.md)
Plan for GIS (.geojson)
Alert draft (CAP .xml)
Copy short summary
Nothing is sent automatically. The files are drafts for exercises: the report for people, the GeoJSON for map tools (QGIS, ArcGIS), the CAP file in the standard alert format, marked "Exercise".
Check a place
Click anywhere on the map: zone, water depth, wave and nearest shelter.
Flood forecast model
Rain and how wet the ground is → river flow → flood size → people and buildings in the water. Trained in your browser on 40 years of rain (ERA5) and river flow (GloFAS) for the river point of the loaded area: external data from Open-Meteo, not challenge data.
Train model
2 · Now: today's data
Last 60 days of rain + the 16-day rain forecast through the model, next to the GloFAS river-flow forecast.
Load today's forecast
Show the last result on the map
Predicts the GloFAS river flow (a model, ~5 km), not gauge readings. Rivers with an upstream area under ~500 km² and town drainage floods are not covered.
One river point for the whole area; rain is the plain mean of a few points around it.
Vesdre check (trained 1984–2014, tested 2015–2021): July 2021 flagged beyond the 1-in-500 flow, one day late; of 2 weeks above the 1-in-10 flow, 1 caught, with 2 false alarms.
Numbers use EFAS depths blended between the 1-in-10/100/500 maps; the map shows the rarest of those maps not beyond the predicted flood.
A planning aid, not a warning: official warnings come from the national services (e.g. SPW / IRM in Belgium, DWD in Germany).
Pick a diagram
Each diagram can be downloaded as an image for the brief, as a vector file for editing, or as a data table (CSV) for Excel.
Team flood API
This tab runs the team's models on the server: any area in the study region, not only the files loaded on the map.
Connect
Connecting…
1 · Area
–
Study area Map view Draw a box
Max 3000 km², inside the study region (DE / BE / NL flood areas). Bigger areas take minutes.
Am I in danger?
Click any place in the study region: flood depth there for each flood size. After an area check (5) it also shows the model risk of that 100 m cell.
Click a place on the map
5 · Area check
Risk per 100 m cell, emergency places and the places to act first. The first run in a new area takes ~2 min (map data download).
Check area
Show on map model risk 1-in-10 water 1-in-100 water 1-in-500 water nothing
Animate this area Back to the study area
Plays the rising water for the checked area in the Simulate tab (EFAS depths; people and buildings only where the API sends them).
6 · Help a friend
Volunteers near a person with a disability get a route that avoids flooded roads. No names are stored; requests are deleted after 72 h.
Flood size1-in-10 1-in-100 1-in-500
Set up help zone Show shelters
Set up once per area (3–4 min, loads all roads); the study area is ready. A zone works only for the area it was set up for.
Helper
Place on map on foot by bike by car Register helper
Person who needs help
Place on map mobility visual hearing other Ask for help
7 · Building damage, July 2021
8 · The models and how well they work
9 · Which policy should the mayor take?
Sends the results of the runs above to the team's policy advisor. It picks from our policies (Policy Brief, Policies since the 2021 flood) and cites the model numbers it used.
Connect
Connecting…
Answer byClaude (Anthropic API key) Local model Rules only (no AI, instant)
LanguageEnglish Français Nederlands Deutsch
Question optional
Get policy advice Run all models + advice
Mayor's decision card
One printable page: what is at stake, the best sequence of actions with times, sources and limits.
Open the decision card
Q2 notes: what has been done since 2021
Your desk research (new defences, rebuilt or abandoned buildings, plans, alert campaigns), with sources. Printed in the report.
Impact for the mayor
Three stages: anticipation, coordination, institutions. Uses the flood size and plan from Evacuate. Change the assumptions below.
Assumptions (illustrative)
What it means for
Municipality / mayor Regional government Civil protection EU level
Model vs the real 2021 flood
Read with care
Flood-size maps are model results, not forecasts of a specific day. Check resolution and flood type in Annex 2.
Satellite maps miss water under trees, in narrow streets, and water that drained before the satellite passed.
"People" means residents: where people live, not where they are during the day.
A building counts when its centre is in a flooded cell. It says nothing about damage.
The video shows the order in which water arrives, not real hours. Each section fills from its riverbed (water level flat across the valley) and the wave moves downstream using Copernicus DEM ground heights. It is not a hydraulic model: no flow speeds, no blocked bridges, no dam effects. The ripples run downhill; their speed is visual only.
Streets, rivers, trees and buildings come from OpenStreetMap. Cars are an illustration, not traffic data.
Evacuation routes, waves and "in time" use your assumptions (capacity, walking speed, warning time) and the flood maps. Check them with local services.