User guide
Two ways to use the atlas
Basic keeps things simple: six core layers with icons, one tap to turn each on, and a plain-language report for any neighborhood you click. Advanced unlocks every dataset, variable switcher, time period, filter, and the report builder. Switch modes any time with the toggle in the top bar; the atlas remembers your choice.
Working with layers
- Layers live in collapsible groups (Flooding, Extreme heat, Severe weather, People, Context). Tap a group header to open or close it.
- Every active layer appears in the widget on the map with its legend. Hover a row for two controls: the pencil opens the style editor (colors, line width, opacity, point size, with a revert button); the x removes the layer.
- Text labels for counties, cities, and towns are layers too, under Context.
- The box in the top-right corner of the map mirrors whatever feature your pointer is over.
Reading a neighborhood
Click any census tract and the side panel returns its combined readout: social vulnerability percentile, population and income, flood-zone share, projected hot days, and plain-language flags an emergency manager would care about.
Building a report (Advanced)
Open the report builder from the side panel. Pick a scope (the whole region or one jurisdiction), tick the sections you need, and check the live preview. Print / PDF produces a clean document; Download CSV exports the tract-level table behind it for your own analysis.
Dark mode
The sun/moon button in the top bar switches themes; the basemap follows.
Frequently asked questions
- Where does the data come from?
- Federal public-domain sources (FEMA, NOAA, CDC/ATSDR, U.S. Census Bureau, USGS/MRLC) and the interagency CMRA projections, each snapshotted into the atlas's own files. The About page lists every source, its license, and its vintage.
- How current is it?
- Each layer's download date is recorded in a metadata sidecar. Storm records run 1950 through 2026; demographics are the 2018-2022 ACS; SVI is the 2022 release; climate projections cover baseline, mid-century, and late-century periods.
- Can I trust the analytics numbers?
- They are screening values built from cited public methods (FEMA benefit-cost policy, NIBS Mitigation Saves 2019, CPI-adjusted NOAA records). Use them to rank places and hazards, then commission a project-level analysis before committing funds. The methodology note states every assumption.
- What projection do the layers use?
- Web display uses WGS 84 (EPSG:4326) / Web Mercator, the standard for browser maps. Source data arriving in Virginia State Plane North (NAD 1983 HARN, US feet) is reprojected on ingest, and exports can be delivered back in State Plane for GIS use.
- Why does a layer say "coming soon" or "data not built yet"?
- The layer is registered but its data pipeline has not been run (or a source server is temporarily refusing requests). The toggle lights up as soon as the data lands.
- Does the map work on my phone?
- Yes. The panel becomes a bottom sheet, feature details open in the sheet instead of small popups, and controls meet touch-size guidelines.
- Who is this for?
- Planners deciding where growth should go, emergency managers pre-positioning for floods and heat, elected officials weighing mitigation spending, and residents checking their own exposure.
Data sources and downloads
- Full data catalog with licenses and credits
- Analytics methodology and assumptions
- Tract-level data: use the report builder's CSV export, or the GeoJSON endpoints under
/geo/. - Economic model:
analytics/loss_model.xlsxin the project repository, with every assumption editable. - Metadata: each data file ships with a JSON sidecar (source, date, record count, CRS); ISO 19115-3 XML starter records accompany them.
Basemap data © OpenStreetMap contributors.