Rekichizu: Designing Modern-Style Historical Maps to Preserve Cultural Memory

広島で行われたFOSS4G Hiroshima 2026での「れきちず」に関する発表スライドです。

※国立情報学研究所（NII）/情報・システム研究機構データサイエンス共同利用基盤施設（ROIS-DS）人文学オープンデータ共同利用センター（CODH）の北本朝展さんと共同登壇しました。

Transcript

1. Rekichizu: Designing Modern-Style Historical Maps to Preserve Cultural Memory 2026.09.03 FOSS4G Hiroshima Hajime Kato (MIERUNE), Asanobu Kitamoto (CODH, NII)
2. Opening Speakers Hajime Kato Asanobu Kitamoto Designer Professor MIERUNE Inc. CODH, NII
3. Opening Today 1. What is Rekichizu? Kato 2. Historical Big Data Kitamoto 3. Sustainability Both
4. 1 What is Rekichizu?
5. Opening Demo Movie
6. Part 1: What is Rekichizu? Historical maps show how our world has changed Shokoku Jokaku Ezu "Hiroshima Castle and its town, Aki Province"/ National Archives of Japan Digital Archive
7. Part 1: What is Rekichizu? Old maps are popular in Japan, but hard to read Walking tours are booming. But three barriers get in the way.
8. Part 1: What is Rekichizu? Barrier 1: Unreadable script Written in cursive brushstrokes. Even Japanese readers cannot read it today. Tempo Kuniezu "Aki-no-kuni" / National Archives of Japan Digital Archive
9. Part 1: What is Rekichizu? Barrier 2: Inconsistent orientation Place names face different directions. There is no single way up. "Tsukiji Hatchobori Nihonbashi-minami Ezu" / National Diet Library Digital Collections
10. Part 1: What is Rekichizu? Barrier 3: Distorted landforms Coastlines and borders do not match modern maps. They can’t be aligned. Tempo Kuniezu "Aki-no-kuni" / National Archives of Japan Digital Archive
11. Part 1: What is Rekichizu? A familiar style solves all three The visual language of modern digital maps
12. Part 1: What is Rekichizu? Reconstructed and made readable "Nihonbashi Kita Kanda Hamamacho Ezu" / National Diet Library Digital Collection
13. Part 1: What is Rekichizu? It started as a personal project A social media post in 2019 got an unexpected response Twitter (X.com)
14. Part 1: What is Rekichizu? A hobby cannot scale • 2019.03 A single image posted online • 2023.08 Released as a personal project • 2024.05 Moved to MIERUNE • 2024.08 Joint research with CODH • 2025.04 Map site for a historical novel
15. Part 1: What is Rekichizu? What Rekichizu can do today • 3D view • Map comparison • GPS mode • Readable in English
16. Part 1: What is Rekichizu? Why not OpenHistoricalMap? • OHM needs public domain sources, but Japanese old maps are not open data • Pre-Edo maps are too rough to trace
17. Part 1: What is Rekichizu? Built by hand in QGIS Old maps for reference, modern maps as the base From 400+ historical sources
18. Part 1: What is Rekichizu? Which places mattered in the past? Not today's tourist spots. Places people actually visited 200 years ago. Sources: ukiyo-e prints, Edo-period guidebooks Hiroshige "Tokaido Gojusan-tsugi Saiken Zue: Hodogaya" / National Diet Library Digital Collection
19. Part 1: What is Rekichizu? Where the data comes from • Rekichizu: 35,000+ km of roads, 6,300+ POIs • CODH: 80,000+ historical place names, coastlines
20. Part 1: What is Rekichizu? Built with open source, published as open data • QGIS: data creation • MapLibre GL JS: frontend • Maputnik: style design Datasets we made with CODH: CC BY
21. 2 Historical Big Data
22. Historical Big Data (HBD) Project https://codh.rois.ac.jp/historical-big-data/ Weather Nature data Earthquake Culture data Population Historical sources Data from Eruption many sources Data Disease structuring are integrated Economy workflow for analysis. Politics Culture 2026/9/3 FOSS4G 2026 22
23. Geography, Document and Toponym Geographic space Toponym (place name) Document space 1. Geographic space includes geometry such as a point or a polygon with their metadata. 2. Document space includes multimodal data such as text or image with regional descriptions. 3. Toponym (place name) connects the two spaces with various metadata (coordinates) about the place. 2026/9/3 FOSS4G 2026 23
24. Edo Maps 8788 Pts 24 2026/9/3 FOSS4G 2026
25. Georeferencing Old Maps Correspondence of GCP National Diet Library ”Edo Kiriezu” 2026/9/3 Ritsumeikan University Map Warper for Japanese FOSS4G 2026 Edo Maps + Map Warper tile service 25
26. 26 2026/9/3 FOSS4G 2026
27. Edo Machiya Dataset (with MIERUNE) 2026/9/3 FOSS4G 2026 27
28. Edo Main Routes Dataset (with MIERUNE) R004 R005 R002 37 main routes (highways), 8360km. More routes to come. R003 R001 2026/9/3 FOSS4G 2026 28
29. Historical Toponym Dataset (with Heibonsha) 2026/9/3 80,502 historical Toponyms from “Nihon Rekishi Chimei Taikei” (Heibonsha) FOSS4G 2026 29
30. With Heibonsha Edo Coast Dataset 30 Edo Lakes Dataset Constructed by hand referring to multiple historical sources 2026/9/3 FOSS4G 2026
31. Dochu: a map viewer for travel 31 加賀藩大名行列図屏風 石川県立歴史博物館 2026/9/3 FOSS4G 2026
32. Historical Big Data Open Research Platform Open Data Place POI Road Coast Others Open Research Data Travel Commerce Politics Disaster Culture Open Research Platform Historical maps (Rekichizu) + modern maps Open-source software tools (use + build) 2026/9/3 FOSS4G 2026 32
33. 27th CODH Seminar Creating and Using Historical Big Data: Handcrafting Processes and Digital Tools for Data 第27回CODHセミナー 歴史ビッグデータの作り方と使い方～ データを手作りするプ ロセスとデジタルツール～ September 18, 2026 Hybrid, Registration required https://codh.rois.ac.jp/seminar/historical-big-data-202609 18/ 2026/9/3 FOSS4G 2026 33
34. 3 Sustainability
35. Part 3: Sustainability & Closing Who builds this data, and keeps it? • Historical GIS is slow to build • Nobody can fund it forever • One person cannot cover a country Academia and industry, working together Results released as open data
36. Part 3: Sustainability & Closing Where Rekichizu goes next The way people see the past More POIs, route search, earlier eras Sample of route search
37. Part 3: Sustainability & Closing Maps preserve what a place used to be
38. Part 3: Sustainability & Closing Thank you Rekichizu ROIS-DS (CODH) Hajime Kato (MIERUNE) Asanobu Kitamoto (CODH, NII)