A web application for analyzing building exposure to flood risk scenarios in Brandenburg, Germany. This tool integrates official flood hazard maps from the Brandenburg State Environment Agency (LfU) with OpenStreetMap building data to provide comprehensive flood risk assessments.
- Interactive Map: Draw polygons to select analysis areas anywhere in Brandenburg
- Official Flood Data: Integrates WMS layers from Brandenburg LfU showing three flood scenarios:
- HQ-200
- HQ-10
- HQ-10/20
- Building Analysis: Automatically fetches all buildings within selected areas from OpenStreetMap
- Risk Assessment: Determines which buildings are affected by each flood scenario
- Land Cover Analysis: Integrates Brandenburg BTLN (Biotop- und Landnutzungskartierung) data to assess flood impact on different land use types (forests, grassland, wetlands, etc.)
- Transportation Network Analysis: Evaluates flood impact on roads and infrastructure (motorways, primary roads, bridges, tunnels) with detailed length affected metrics
- Census Population Integration: Calculates actual population in analysis areas using official 2022 German census data
- Accurate population counts by commune intersection
- Population at risk estimation based on affected buildings
- Population density calculation per km²
- List of affected communes with population breakdown
- Detailed Statistics:
- Total buildings analyzed
- Buildings at risk by scenario
- Census population in analysis area
- Estimated residents at risk
- Breakdown by building category (Residential, Commercial, Industrial, etc.)
- Breakdown by specific building types
- Data Export: Export complete analysis results to CSV format
Brandenburg.Flood.Risk.Assessment.-.Brave.2025-12-30.13-11-47.mp4
- User draws a polygon defining the area of interest.
- All buildings within the polygon are retrieved via the OpenStreetMap Overpass API.
- Building centroids are calculated for spatial queries.
- For each building, flood exposure is determined by querying official LfU WMS layers (HQ-200, HQ-100, HQ-10/20).
- Results are aggregated by building type, land use (BTLN), and census population data.
- Summary statistics and affected features are visualized and exported as CSV.
- Frontend: React 18 with Vite
- Mapping: Leaflet with Leaflet.draw for polygon drawing
- Deployment: GitHub Pages with automated GitHub Actions workflow
- Flood hazard maps: Brandenburg Landesamt für Umwelt (LfU), provided via WMS services
- Building data: © OpenStreetMap contributors (ODbL)
- Land cover data: Brandenburg BTLN
- Population data: German Census 2022 (Zensus 2022)
Flood exposure is evaluated using WMS GetFeatureInfo requests, which are designed for interactive map queries rather than large-scale batch analysis. For large areas with many buildings, processing time may increase due to network latency and service-side rate limiting.
- Clone the repository:
git clone https://github.com/pixelpawnshop/Brandenburg-Flood-Risk.git
cd Brandenburg-Flood-Risk- Install dependencies:
npm install- Start the development server:
npm run devThe application will open at http://localhost:3000
Build the application:
npm run buildPreview the production build:
npm run preview- Update the
basepath invite.config.jsto match your repository name:
base: '/your-repo-name/',- Deploy to GitHub Pages:
npm run deployOr set up automated deployment with GitHub Actions (workflow included in .github/workflows/deploy.yml)
- Integration of flood protection infrastructure (e.g. dikes and levees)
- More precise population distribution using building-level occupancy estimates
- Inclusion of historical flood events and observed water levels
- Damage cost estimation models based on building types and flood depth
- Support for additional or custom flood scenarios
MIT License - feel free to use this project for learning purposes.
Note: This application uses publicly available data sources. For official flood risk assessments and planning decisions, please consult the Brandenburg Landesamt für Umwelt directly.