nyampire's Diary

Recent diary entries

Repair method of large multipolygons from backup pbf files?

Posted by nyampire on 26 August 2019 in English (English).

I’m working on repairing the forest multipolygon in Hokkaido. They are deleted/modified/destroyed badly for several weeks ago.


It is very hard to repair with revert or redrawing, because the damage is too serious and complex. So I would like to reuse the polygons from old planet files if possible.

But I’m facing versioning issues. Anyone has more easy solution?

  • Extract multipolygon relation using osmium: Like those command.

osmium getid -r ./hokkaido-190601.osm.pbf r1083877 -o r1083877.osm

  • Merge: Merging those polygon and current data using JOSM merge selection.
  • Upload: It causes numerous conflicts due to object version is smaller than’s current objects.

Should I tweak the xml file for versioning? (e.g. using sed or some other methods)

P.S. The vandal mapper is editing his edit ignoring my message/changeset comments. I already reported this with’s reporting feature.

He is deleting my repair works, so quite problematic…

Notes for Ichi-Sansho-Joho dataset

Posted by nyampire on 16 August 2019 in English (English). Last updated on 17 August 2019.

I’m now taking a look on Ichi-Sansho-Joho data from MLIT, Japan. This is quite powerful dataset about place name, and could be used as OpenStreetMap edits. (include imports, although it is not fully activated)

Seeing Japanese place/address name sample structure, some errors might be contained. This is a note for further works.

  • “11”,”埼玉県”,”11234”,”八潮市”,”112340013002”,”大字二丁目”,”35.821729”,”139.846276”,”0”,”3”

-> Code 3 could be error. Code 1 would be correct. This is quarter named “大字二丁目”. Despite of “丁目” is included.

  • “27”,”大阪府”,”27145”,”堺市南区”,”271450017000”,”竹城台四丁”,”34.498107”,”135.500217”,”0”,”1”
  • “27”,”大阪府”,”27145”,”堺市南区”,”271450035000”,”竹城台二丁”,”34.498169”,”135.505486”,”0”,”1”
  • “27”,”大阪府”,”27145”,”堺市南区”,”271450074000”,”竹城台三丁”,”34.493790”,”135.503225”,”0”,”1”
  • “27”,”大阪府”,”27145”,”堺市南区”,”271450075000”,”竹城台一丁”,”34.500963”,”135.510525”,”0”,”1”

-> Probably original structure is correct, but “n丁” should be devided in the case of use for OSM. Those are Code 1 column, but should be treated as variant of Code 3.

  • “04”,”宮城県”,”04103”,”仙台市若林区”,”041030090000”,”蒲町東”,”38.245498”,”140.932557”,”0”,”3”
  • “07”,”福島県”,”07207”,”須賀川市”,”072070142000”,”北山寺町”,”37.30542”,”140.364113”,”0”,”3”
  • “07”,”福島県”,”07207”,”須賀川市”,”072070143000”,”西山寺町”,”37.303127”,”140.358357”,”0”,”3”
  • “07”,”福島県”,”07207”,”須賀川市”,”072070144000”,”山寺町”,”37.302309”,”140.364716”,”0”,”3”

-> Code 3 might be error. I guess those lines should be Code 2.

And Code 3 lines (丁目) should be divided into 2 nodes. (quarter (町名) and neighbourhood (丁目).) Some quarter might be duplicated to Code 1 lines.

And it seems “釧路市昭和”(大字, quarter)and “釧路市昭和町” are same district, but need more check if it is correct.

Farmland data from Japanese Government

Posted by nyampire on 10 April 2019 in English (English).

Last week, MAFF (Ministry of Agriculture, Forestry and Fisheries, Japan) has published farmland data for entire Japan.

It is under MAFF original license, but it allows pretty similar to JP Gov’s Open License. (based on JP Gov’s default one, but seems more open) I guess it need to ask them if we could use/import them to OSM, but I hope we have a chance :)



Details are not available. But seeing some regions, it is quite accurate with GSImap(map from JP government) and OpenStreetMap.


I guess it could be challenging, at least this time.

Community consensus

  • This data has polygon for each farmland. (original usage is farmland cadastra) So some mappers did another way of editing (combining several field as 1 polygon)
  • Tagging. (each polygon has “landuse=farmland”?)

License Compatibility

  • Their Clause 3)ウ has “users should announce this term of use for all of he users” could be an issue. Need to ask.

Huge dataset!

  • It has 30,951,173 polygons total!
  • Geometry alignment with existing data in OpenStreetMap (Country roads in Japanese OpenStreetMap is 1:25000 from old import, and forest data from KS2 old import is also still messy)

But … I’m very excited to see that!

Mapping 1:25000 area in Japan [WIP]

Posted by nyampire on 30 July 2018 in English (English).

I’m preparing my new project regarding Japan region. Here is some memo.


In Japan region, we OpenStreetMapper may trace governmental map.

Especially, GSI map has pretty precise and having good accuracy.

GSI map is based on KibanChizuJoho (Fundamental Geo Data) data which is protected by Japanese Survey law. KibanChizuJoho is an aggregated geo data gathered from municipalities.

Accuracy of KibanChizuJoho is 1:2500 (for urban area) or 1:25000 (for country area). My idea is to cover this 1:25000 area with OpenStreetMap.

List of 1:25000 area

GSI has been publishing those area as following tiled format.

I’ve made a geojson using a script provided by my friend.

Here is a list of municipality which has 1:25000 area. Not perfect through.

This list indicates 800, out of around 1800, are target.


Current available imagery resource is not so clear on country side. (Bing, Mapbox, DG or GSI ortho)

But most of JP municipality is taking aerial imagery by several years period.

Some of those are published under open license. And Mappers are using them as editing resources. (sample: Shiuoka-city on OSM wiki) I would like to encourage to publish the imagery.


Fake University has Fake OSM maps?

Posted by nyampire on 14 June 2018 in English (English).

Japanese famous (prank and imaginary *note) university “Shinsyu University of International” announces they have switched their access map to OpenStreetMap. It shows their campus in interactive map.

It was reported via twitter, and I have checked if it causes vandalism or something worse.

But curiously, there are no such a campus data on

As checked html source of the page, I found they built their own map instance. From their html,


In order to avoid harm to OSM website, and due to OSM does not show “Shinsyu University of International” in their map (Probably we are not so famous), so render our map if zoom level upper 12 and near the campus.

Nice joke, I’m tricked :)

*note: SUI claims they are REAL university.

Idea for Peer review workflow using OSMcha

Posted by nyampire on 24 August 2017 in English (English).

First of all, thank you for participating to SotM 2017 Aizuwakmatsu!

Unfortunately I was not able to talk to every persons due to my staff work, but I could talk with Arun following idea. I would like to hear more broader suggestions & feedback.


To establish peer review operation workflow especially regarding newbie mappers.

Approach & Tools

OSMCha has feature to detect specific #hashtag on changeset comments or specific tags on changeset. So my main idea to encourage mappers to add special meta data to the changeset if he/she want the edits to be peer reviewed. I guess it is possible to add comments e.g. #needreview on special changeset comment or need_review=yes or other information on changeset tag.

If those tags are set, it maybe possible to detect such a message through OSMCha easily.

Idea for iD Editor integration

Yes, it is too difficult to encourage newbie mappers to add such a information. Because they are a previous stage to understand how those messages are important.

So my suggestion to add a function to iD editor. At the commit (save) screen on iD, it is set a checkbox Need Review or Ask someone to Review to add above hashtag or changeset tags.


Sometimes newbie mappers worried about if their changes crushes data structure or if they could set appropriate tags.

This might be a “Please help me!” message from newbies. So veteran mappers may easily contact to them to lead proper information such as OSM wiki Tagging page. If the newbie could be contacted once, they can aware OSM community. I think it is easier to involve them to our community. (Perhaps it would be better to contact the native language at messaging. But it is an optional issue.)

Possible Pros & Cons

## Pros * “Need help” mappers are to be more prospective to “stay” in OSM editing than simply automatic Welcome message. (And existing mappers can know newcomer’s motivation) * Most of the features in this flow (e.g. changeset word detection, fetching and contact to the usr etc…) are already implemented in site and OSMCha. So it might be less effort to code.


  • Although it might need less effort than more bigger changes, it need some programming hack.
  • Unfortunately I do not have programming skill to be happen this idea…

Feedback is welcomed.

日本の衛星画像 (Satellite imagery in Japan)

Posted by nyampire on 12 November 2015 in Japanese (日本語).

This article is translation of PlaneMad’s diary


標準的に利用される Bing画像ですが、日本地域では全体的にオルソ化の精度が低いようです。以下は私たちが見つけた新東名高速道路の一部で、歪みが非常に明瞭にわかります。 > 富士山の近くのBIngと地理院地図オルソ画像の比較

日本地域でトレース用に利用する正しい画像は、国土地理院 (Geospatial Information Authority of Japan, GSI) から提供される画像です。sourceタグは source=GSImaps/ort、タイルのURLは{z}/{x}/{y}.jpg で利用することができます。


東京地域の道路改良 (Tokyo Road Improvement)

Posted by nyampire on 12 November 2015 in Japanese (日本語).

This article is translation of pratikyadav’s diary


日本の道路改良シリーズのなかで最も重要なプロジェクトである、tasking managerを使って、東京近郊地域の主要道路地理院地図オルソ画像をもとに修正するという作業が完了しました。

本プロジェクトの内容: - 主要道路 (motorway, trunk, primary, secondary. 日本語では、それぞれ主に高速道路、国道、都道府県道を含む主要地方道) の位置修正とマージ作業 - 中央分離帯で分割された道路の二車線化と加速車線の修正、一方通行属性の修正

日本で行ってきたこれまでの道路改良プロジェクト (九州大阪水戸福島石川別府大分青森北陸奥) と比較し、東京地域は地理院地図オルソ画像と比較し、良好な位置精度を有していました。

このプロジェクトは630のブロックに分割され、プロジェクトの支援を行う Mapbox Data team からの19名と日本OSMコミュニティを合わせて総計31名の参加によって行われました。




より詳しい情報は Data issues in Japan (日本語) で解説されています。公開で議論されている Mapbox project trackerのデータクリンナップ進捗状況もチェックしてみてください。

新年の抱負 2014

Posted by nyampire on 6 January 2014 in Japanese (日本語).

According to Japanese tradition, I write some plans of this year.

Fill the Missing

  • Municipality administration boundary re-import

Boundary data (Prefecture & City level) is completely broken by the result of reduction. So we could not get correct Nominatim search, nor extract from OverPass area query.

I really hope to rebuild of them.

Last year, I was discussed on talk-ja ML and got achievement about the structure refinment of address and place name in Japan. It’s time to go forward.

Challanges are…

  • Old data
  • should be deleted or conflated into new ones.
  • Data size
  • Dataset are a bit big to upload at once.
  • need upload each municipality separately, “then” stitch them on OSM?
  • Conflation with coastline?
  • boundary data from KSJ2 is not accurate on newly reclaimed land.
  • It’s better to merge with existing coastline data. (Optional or Mandatory?)

  • Forest on Kyusyu, Shikoku area
  • Method: Thinking of trace from Bing.
  • Re-import of KSJ2 Forest data is pending. Because of their accuracy (1/25000)
  • Problem is some “Out of Bing coverage” area.

  • Bracket on name tag
  • Discussed on talk-ja ML last year, bracket in name tag like “なにか (SOMETHING)” should not be added on newly edits.
  • Switching existing data (in another word, deleting bracket) is now pending, due to some mappers claim hardly some Multilingual supports.

OpenData anyway

As increasing activity for OpenData, some local government had started publishing their data under CreativeCommons or similar license. Even Japan Government has started “” as their catalog site.

We Japanese must make a guideline for using them in OSM. (as “reference information” not direct import)

Reducing Data Size

Old KSJ2 import data has too many useless tags (even on node!). It is better to purge them out.

Empower Community

I would like to hold more Mapping Party, or Hack Day.

And as a member of OSMFJ, I’ll maintenance “” webpage as a hub site.

Hoping this year will be mappy :)