Journal Digital Corpus Map

An interactive geographical visualization tool for corpus metadata. Displays dual heatmaps of location data with temporal animation capabilities.

Funding Acknowledgment

This interface is part of the research project 'Modern Times 1936' financed by the Bank of Sweden Tercentenary Foundation (Riksbankens Jubileumsfond, grant number P21-0012).

About

This is a static website that visualizes geographical metadata from two sources:

• JDC Speech: Named entity recognition results from the Journal Digital Corpus
• SMDB-SAB: Location metadata from the Swedish Media Database

The visualization allows you to:

• View dual heatmaps of location mentions over time
• Animate through temporal data with a configurable moving window
• Search for specific locations
• View statistics and trends in the sidebar

Usage

Map Interaction

• Pan: Click and drag the map
• Zoom: Use mouse wheel or zoom controls
• Toggle Layers: Use checkboxes in the sidebar to show/hide each metadata set

Timeline Controls

• Play/Pause: Animate through time automatically
• Window Size: Adjust the time window (in years) to aggregate data
• Delay: Set animation speed (seconds between steps)
• Step Size: Set how many years to advance per animation frame

Search

• Type a location name in the search box
• Click on a result to focus the map on that location

Statistics

• View location counts over time in the sidebar chart
• Drag the brush on the chart to change the current time window
• See breakdown by location type (city, village, etc.)

Data Sources

Journal Digital Corpus

Aspenskog, H., Johansson, M., & Nordström, L. (2025). Journal Digital Corpus: A Swedish Newsreel Transcription Corpus. Under review.

This visualization uses named entity recognition results extracted from Swedish newsreel transcriptions using the KB-BERT model.

Svensk Mediedatabas (SMDB)

Location metadata extracted from the Swedish Media Database's SAB collection.

Technology Stack

Core Visualization Libraries

• D3.js v7.8.5 (Bostock et al., 2011) - Data-driven visualization library for heatmaps and charts
• Leaflet.js v1.9.4 (Agafonkin et al.) - Interactive mapping library

Map Data & Geocoding

• OpenStreetMap (Haklay & Weber, 2008) - Collaborative open map data
• Nominatim (OpenStreetMap Foundation) - Geocoding service for location data
• Geofabrik - OpenStreetMap data extracts
• Nominatim-Docker (mediagis) - Containerized geocoding service

Web Technologies

• JavaScript/ECMAScript 2023 (Ecma International) - Programming language
• HTML5 (W3C) - Document structure
• CSS3 (W3C) - Styling and layout

Build Tools

• Vite v5.0 - Fast build tool and development server
• Node.js (OpenJS Foundation) - JavaScript runtime environment
• npm - Package manager
• Python 3 (Van Rossum & Drake) - Data processing scripts

NLP Tools

• KB-BERT NER Model (KB Labb, 2022) - Swedish named entity recognition for location extraction

Development Assistance

• Claude 4.5 Sonnet (Anthropic, 2025) - AI language model
• Claude Code (Anthropic, 2025) - AI-powered development CLI

Data Format

The application loads three JSON data files:

Corpus Metadata Files

• corpus-metadata-1.json: JDC Speech location mentions by year
• corpus-metadata-2.json: SMDB-SAB location metadata by year

Each file contains an array of items with:

• id (string): Unique identifier
• year (number): Year associated with the item
• locations (array): Array of location IDs

Locations File

• locations.json: Geocoded location data

Contains an object mapping location IDs to location details:

• name (string): Short location name
• display_name (string): Full display name
• type (string): Location type (building, village, city, region, province, country, continent)
• lat (number): Latitude coordinate
• lon (number): Longitude coordinate
• boundingbox (array, optional): Bounding box [minLat, maxLat, minLon, maxLon]

Acknowledgments

This interface is part of the research project 'Modern Times 1936' financed by the Bank of Sweden Tercentenary Foundation (Riksbankens Jubileumsfond, grant number P21-0012).

Developed collaboratively using Claude 4.5 Sonnet via Claude Code CLI.

Source Code

The source code for this project is available in a separate repository. This repository contains only the built static website.

License

MIT

Contributing

For issues or suggestions, please use the GitHub issue tracker.