Microproduct Data GuideIntermediate

FOEN National Flood Warning Map

Swiss federal flood-warning map layer for checking official warning levels near mapped destinations.

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At a Glance

Difficulty
Intermediate — some data preparation helps
Size
Tiny · ≤0.01 GB
Formats
GeoTIFF
Access
API
API Key
Not Required
Provider
Swiss Federal Office for the Environment
Updates
Near Real Time
Last Verified
Sep 28, 2026
Source Type
Government Source
Data Terms
The Swiss catalog marks this layer for unrestricted open use, including commercial analysis; source credit is recommended and geo.admin fair-use limits apply.
  • Python Syntax Checked

From Source to Product Signal

Test a Product Idea in Four Steps

FOEN publishes the ch.bafu.hydroweb-warnkarte_national layer through the federal WMS. Start with a small map image; its warning colors are not direct gauge measurements.

1

Check the Setup

  • Python 3.10 or newer
  • An internet connection
  • The requests Python package
2

Access the Data

  1. 1.Review the official flood-map catalog record and open-use condition.
  2. 2.Request a bounded WMS image of the exact FOEN warning layer.
  3. 3.Read its legend before assigning meanings to colors.
Open Official Source
3

Run the Python Example

Install the packages, then run the notebook cell.

python -m pip install requests

import requests

response = requests.get(
    "https://wms.geo.admin.ch/",
    params={"SERVICE": "WMS", "VERSION": "1.1.1", "REQUEST": "GetMap",
            "LAYERS": "ch.bafu.hydroweb-warnkarte_national",
            "STYLES": "default", "SRS": "EPSG:4326",
            "BBOX": "5.9,45.8,10.6,47.9", "WIDTH": 64, "HEIGHT": 32,
            "FORMAT": "image/tiff"}, timeout=25,
)
response.raise_for_status()
assert response.content[:4] in (b"II*\x00", b"MM\x00*"), "Expected GeoTIFF"
print("FOEN warning-map bytes:", len(response.content))
4

Test a Useful Signal

Inspect a Swiss Flood-Warning Tile

Display a small official warning-map image with its source and extent.

  1. 01Fetch the named FOEN WMS layer.
  2. 02Show its map bounds and official legend link.
  3. 03Explain that colors represent warnings, not measured water height.

Related Datasets

Dataset Details

Swiss Federal Office for the Environment is a government source. Last verified 2026-09-28. Temporal coverage: current national flood-warning map.

Data Types

Raster

Geography

Switzerland

Formats

GeoTIFF

Provider

Swiss Federal Office for the Environment

Data Terms

The Swiss catalog marks this layer for unrestricted open use, including commercial analysis; source credit is recommended and geo.admin fair-use limits apply.

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