Welcome to OpenHVRA

OpenHVRA is a free web tool for disaster risk practitioners. It runs a rapid, screening-level hazard, vulnerability and risk assessment for any place on Earth using open data: OpenStreetMap buildings, facilities, roads and rivers, open elevation data, the USGS earthquake catalogue and World Bank demographics. There is nothing to install, and the files you upload stay in your browser.

What it can tell you

• How many people, buildings and critical facilities are near rivers, streams or roads, live as you move the mouse.
• The estimated population of every building.
• Flood depth, losses and average annual loss, and how to finance them (reserve funds, contingent credit, insurance).
• A social vulnerability index, and counts of children, elderly people, people with disabilities and people in poverty.
• Multi-hazard scores for river and flash floods, landslides, earthquakes, coastal floods, glacial lake outbursts and avalanches, plus a combined risk map and a risk matrix.

How to run an assessment

1. Find your area. Search for a place, or zoom in on the map.
2. Select the area (step 1). Draw a rectangle, circle or polygon with the buttons in the panel or the toolbar at the map's top-left. You can also upload a boundary file (zipped Shapefile, GeoJSON, KML/KMZ, GPX, GeoPackage or WKT), drop one on the map, or use the current view. Areas can be up to 60 km² in Light mode or 25 km² with Footprints.
3. Load OSM data. Tick the layers you need and click Load OSM data. It takes from 10 seconds to a couple of minutes, depending on the public servers. Loaded areas are saved in your browser for 3 days.
4. Check the population model (step 2). Adjust the floor area per person and the default number of storeys, or enter a census total to calibrate.
5. Explore. Move the mouse over the map to see live counts within the chosen radius, and click to pin the circle. Step 4 counts everything within a set distance of rivers or roads. For rivers, it also uses elevation to leave out buildings well above the water and to flag buildings on steep, erodible banks.
6. Flood risk and risk finance (step 5). Enter the water level for each return period and the local construction costs, then run it to get losses, the loss curve, average annual loss and the financing layers.
7. Social vulnerability (step 6). Click Use national figures to fill in the vulnerable-group shares, optionally upload a census layer such as poverty by ward, then compute.
8. Multi-hazard risk (step 7). Choose the hazards and their weights, and for GLOF check the glaciers, lakes and traced outflow paths on the map: mark missing lakes or glaciers, or draw a lake's path yourself if it looks wrong. Then run it to see the risk matrix, the hotspots and the combined risk map.
9. Report and export (step 8). Download full package gives you a ZIP with a written summary, all your settings, a detailed table for each step you ran, publication maps and charts, tables for every building and facility with all analysis values, the risk-matrix calculation, and the map layers for QGIS. The checklist has a CSV for each completed step. Each step also has a Map (PNG, 300 DPI) button and charts you can download as SVG or PNG for reports and papers. Hover over any building or facility for its details. The Layers box at the bottom-left of the map switches the basemap, turns layers on and off, and shows each layer's legend. The 3D button shows the terrain and buildings at their real height (right-drag or Ctrl+drag to tilt and rotate).

Good practice

• Start with a single village or ward, then expand.
• Replace the default water levels, costs and shares with local data.
• Results depend on how completely OpenStreetMap covers your area. Check against the satellite basemap and help improve the map.
• These are screening estimates for prioritisation. Verify hotspots in the field and against official hazard maps.

Data: © OpenStreetMap contributors (ODbL), Overpass API, AWS Terrain Tiles, USGS, World Bank, Nominatim. Created by Gomal Amin. Version . Source code: GitHub (MIT License).