Navigating Map of Denmark under Changing Sea Levels

BFST2026 — First Year Project, Spring 2026 Group 20 — IT University of Copenhagen

An interactive map application for exploring regions of Denmark with real-time sea level simulation and dynamic route finding. Built as a first-year project at ITU Copenhagen, Spring 2026.

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Features

• Map rendering — Loads and renders OpenStreetMap data with distinct styling for road types, bodies of water, and other OSM features
• Sea level simulation — Raise the simulated sea level via a slider and watch affected areas update dynamically on the map
• Route finding — Compute the shortest route between two points using A*, with automatic rerouting when roads become submerged
• Binary caching — Raw .osm and .hc files are parsed once and saved as binary cache files, reducing subsequent startup times by ~27.8×

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Prerequisites

• Java 21 or later
• Maven 3.8 or later
• JavaFX 21 (bundled via Maven dependencies — no separate install needed)

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Getting Started

1. Clone the repository

git clone https://github.com/SimonGSK/Navigating-Map-of-Denmark-under-Changing-Sea-levels.git
cd Navigating-Map-of-Denmark-under-Changing-Sea-levels

2. Build the project

mvn clean install

3. Run the application

mvn javafx:run

On launch a startup dialog will appear with three pre-loaded options:

• Bornholm — the primary dataset (588 km², 800,000+ elements)
• Tunø — smaller island, useful for quick testing
• Samsø — medium-sized island

Simply click one to load it. Alternatively, use the "Load custom files" option in the dialog to load your own .osm and .hc files from disk.

Binary cache files (.bin) are generated automatically on first load of each dataset and reused on subsequent launches for faster startup (~27.8× speedup).

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How to Use

Action	How
Pan the map	Click and drag
Zoom	Scroll wheel and the +/- buttons in the toolbar
Adjust sea level	Use the slider in the toolbar
Set route start/end	Press S to enter selection mode, then click once for start and once for end
Reset interface	Press esc to reset the interface and enter exploration mode
Load a different map	Use the file menu to open new .osm and .hc files

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Project Structure

src/
├── main/java/
│   ├── models/RTree/          # R-Tree spatial index
│   ├── models/pathfinding/    # Dijkstra and A* implementation
│   ├── models/parser/         # OSM and height curve parsers, binary cache
│   ├── models/geometry/       # AdaptivePath (RDP simplification), BoundingBox
│   ├── models/heightcurve/    # Height curve tree and submergence simulation
│   ├── models/rendering/      # Map rendering pipeline
│   └── models/ui/             # JavaFX application and event handling
├── main/Resources/data/       # Bundled datasets (Bornholm, Tunø, Samsø)
└── test/java/util/            # JUnit 5 test suite

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Running the Tests

mvn test

The test suite uses JUnit 5 (Jupiter) throughout with no mocking framework. Tests cover the R-Tree, pathfinder, height curve system, AdaptivePath (RDP), and both parsers.

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Known Limitations

• Tunø submergence — The submergence simulation does not behave entirely correctly for Tunø due to a mismatch between the OSM and height curve ID systems. Bornholm and Samsø are unaffected.
• Submerged road segments — Submergence is checked at the node level only. A road segment whose endpoints are both above sea level will not trigger a reroute even if the segment itself passes through a flooded area.
• Zip file support — The parser reads plain .osm and .hc files only. Zipped files are not supported and must be unzipped before loading.

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Group Members

Name	Email
Hannibal Munk	hmun@itu.dk
Daniel Kyhl	daky@itu.dk
Simon Skouboe	sgsk@itu.dk
Filip Jacobsen	fija@itu.dk

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Built With

• Java 21
• JavaFX 21
• Apache Maven
• JUnit 5
• JMH — for benchmarking