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How should Tsunami Hazard Zones be mapped? Are there any tags that should be used?


On 14 November 2016 New Zealand experienced a magnitude 7.8 earthquake. Due to the strength and length of the shaking, many people in coastal areas self-evacuated to high ground, often travelling many kilometres on earthquake damaged roads. While many local authorities had published maps for "Tsunami Hazard Zones" and evacuation areas these were mostly in PDF format and totally unsuitable for use on a mobile phone or gps unit.

Some local authorities, for example, Wellington City Council, have painted road markings to indicate where the hazard zones are. After the earthquake Wellington people went out of those marked hazard zones where these were marked on the roads. But in the rest of the country there was a lot of confusion and panic because people could not access the mapping information. Fortunately, in most places the tsunami was more like a storm surge that was confined to the beaches, although one unoccupied house was destroyed by a 4 metre wave due to local conditions.

asked 26 Nov '16, 22:38

Huttite's gravatar image

accept rate: 0%

I don't think that data from local authorities about hazard zones published in PDF form should be added to OSM just because that makes the data easier to consume on mobile phone or GPS units. My reasons include: * the licensing is unclear * the data is, with the exception of areas where hazard zones are denoted by road markings, not verifiable on the ground which means that wrong or outdated information will be difficult to spot * being included in OSM wouldn't automatically make this map visible on mobile phone or GPS units

This calls for a separate project where people get together, bring the data into a mobile app or a Garmin map file - perhaps using OSM as a base map if desired - and build an useful emergency map style, perhaps even including "hazard routing" that avoids marked roads and so on.

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answered 26 Nov '16, 23:07

Frederik%20Ramm's gravatar image

Frederik Ramm ♦
accept rate: 23%

Setting aside the issue of the PDF maps, how should Tsunami Hazard Zones that have road markings be mapped?

Note: The licencing of the PDF maps are probably going to be some form of CC-by-SA since that is the licencing standard New Zealand is moving to for government related mapping information as part of its Open Data policy.

(26 Nov '16, 23:20) Huttite

I'm a bit surprised about some of the comments: tsunami evacuation routes & assembly zones have been actively mapped in Indonesia as part of the HOT / Inasafe activity for perhaps 10 years now. There must be considerable experience in what it is appropriate to map & how to map it.

Inasafe itself is a FOSS plugin package for QGIS designed for planning around natural hazards, and includes an OSM download tool (reflecting tag usage in Indonesia).

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answered 22 Mar '21, 19:37

SK53's gravatar image

SK53 ♦
accept rate: 22%

🧟 Reviving a very old thread!

In Wellington the tsunami safe zones are increasingly being signalled on-site... There are roadmarkings indicating which direction and how far the safe zone is, more roadmarkings indicating the start of a safe zone, and sometimes signs as well.

roadmarking indicating tsunami safe zone 230m up the hill

It's super important information for locals, how should we be mapping these?

sign indicating a tsunami safe zone

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answered 22 Mar '21, 00:35

cameralibre's gravatar image

accept rate: 0%

From this and the lack of further comment I conclude that only features visible on the ground should be mapped. So if a Tsunami Safe Assembly Zone is signposted, it could be mapped. But as for mapping the hazard zones, if they only appear on a map, but do not appear on the ground, then these should not be added to OSM.

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answered 01 Jan '17, 01:47

Huttite's gravatar image

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question asked: 26 Nov '16, 22:38

question was seen: 3,085 times

last updated: 22 Mar '21, 19:37

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum