An interactive web application for visualizing internal migration flows across Indian states with dynamic boundary loading and detailed migration analytics.

• Interactive Migration Map: Visualize in-migration (blue), out-migration (red), and net migration (white dashed) flows
• Dynamic Boundary Loading: 10 levels of geometric simplification based on zoom level
• State Selection: Click on states or flows to highlight related migration patterns
• Detailed Analytics: Side panel showing detailed migration data for selected states
• Filter Controls: Toggle different flow types and adjust minimum flow thresholds
• Keyboard Navigation: Press ESC to deselect and return to hover mode

• Backend: Flask with Python
• Frontend: Leaflet.js, HTML5, CSS3, JavaScript
• Data Processing: Pandas, GeoPandas, Shapely
• Dependencies Management: uv (Python package manager)

• Python 3.12+
• uv package manager

1. Clone the repository:

git clone https://github.com/amitportal/india_internal_migration_mapping.git
cd india_internal_migration_mapping

2. Install dependencies using uv:

uv sync

The application requires the following data files in the root directory:

• IND_5yrs_InternalMigFlows_2010.csv - Migration flow data
• india_states.geojson - Indian state boundaries

1. Run the application:

uv run python app.py

2. Open your browser and navigate to http://localhost:5000

The application expects a CSV file with the following columns:

• ISO: Country identifier
• NODEJ: Origin node ID
• NODEI: Destination node ID
• LONFR, LATFR: Origin coordinates
• LONTO, LATTO: Destination coordinates
• PrdMIG: Migration volume

State boundaries should be in GeoJSON format with:

• state: State name
• country: Country name (should be "India")
• geometry: State boundary geometry

• Hover: Shows state names and highlights related flows (when no selection is active)
• Click on State: Highlights all flows to/from that state, shows detailed information
• Click on Flow: Highlights all three flow types (in, out, net) between the two states
• ESC Key: Deselects current selection and enables hover functionality
• Zoom: Dynamically loads boundaries with appropriate detail level

• Red Lines: Out-migration flows (from origin state to destination)
• Blue Lines: In-migration flows (to destination state from origin)
• White Dashed Lines: Net migration flows (balance between in and out migration)

• Toggle flow types (in-migration, out-migration, net migration)
• Adjust minimum flow size with slider
• Reset highlighting functionality

The application follows a client-server architecture:

• Handles data loading and processing
• Provides API endpoints for:
  • Boundary data with zoom-level appropriate simplification
  • Migration flow data
  • State-specific migration details
  • Overall statistics

• Interactive map interface
• Dynamic loading of data based on zoom level
• Flow visualization with Bezier curves
• Selection and highlighting logic

The application uses 10 zoom levels with the following simplification factors:

• Level 1 (zoomed out): 5.0 (highest simplification)
• Level 10 (zoomed in): 0.5 (lowest simplification, most detail)

1. Extend the Flask API in app.py for backend functionality
2. Update the JavaScript in templates/index.html for frontend interactions
3. Consider the selection priority system (click > hover) when adding new interactions

• The 10-level simplification system balances detail and performance
• Flow rendering is limited to prevent visual clutter
• Boundary loading is optimized based on current zoom level

The following Python packages are required:

• Flask: Web framework
• pandas: Data manipulation
• geopandas: Geospatial data processing
• shapely: Geometric operations
• numpy: Numerical operations

• uv: Package manager

• GET / - Main application page
• GET /api/boundaries?zoom={level} - State boundaries for zoom level
• GET /api/flows?min_flow={threshold} - Migration flows above threshold
• GET /api/net_migration?min_flow={threshold} - Net migration flows
• GET /api/state_migration/{state_name} - Detailed migration data for state
• GET /api/stats - Overall migration statistics

1. Missing Data Files: Ensure IND_5yrs_InternalMigFlows_2010.csv and india_states.geojson are in the root directory
2. Performance: Large zoom levels or high flow thresholds may affect performance
3. Coordinate Systems: All data should use EPSG:4326 (WGS 84) coordinate system

• Modern browsers with JavaScript enabled
• Supports major browsers including Chrome, Firefox, Safari, Edge

This project is released under the MIT License. See the LICENSE file for details.

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

• Caching for boundaries and Bezier curve calculations
• Additional filtering options
• Export functionality
• Time-series visualization
• Additional geographic projections

• Amit Kumar

• Migration data for research and analysis purposes
• Leaflet.js for interactive mapping capabilities
• OpenStreetMap for base map tiles