nvTopo

100%

✓ Published0🌍 Public

Last edited Jun 25, 2017

Created on Jun 25, 2017

This choropleth map visualizes population density across Nevada census tracts, with each polygon colored on a yellow-orange-red sequential scale using a threshold color scale. The map uses TopoJSON data rendered as SVG paths, with county boundaries stroked in dark goldenrod over the tract-level fills. A horizontal legend at the bottom maps population per square mile using a square-root scale, and interactive tooltips display the exact density value for each tract on hover.

AI-generated description

Built with blockbuilder.org

mit Licensed

Similar vizzes

Loading thumbnail…

Merged Choropleth

This choropleth map visualizes population density across California census tracts, using the 2014 American Community Survey 5-Year Estimate. The map merges adjacent tracts with similar density into single polygons, reducing the file size from 1.5M to 328K and improving rendering speed and visual clarity. The d3.geoPath renders the projected shapes, while d3.scaleThreshold and d3.schemeOrRd assign colors, and d3.scaleSqrt positions the legend. The code uses topomerge and toposimplify from the topojson library to consolidate boundaries, with county borders overlaid as an outline.

Mmbostock

73% match

Loading thumbnail…

Untitled

A choropleth map of population density per square mile colors U.S. census block groups using a threshold scale and the sequential color scheme `d3.schemeOrRd[9]`. The visualization includes a square-root-scaled legend with an axis, and overlays county boundaries as black strokes at 30% opacity. The code loads TopoJSON data via `d3.json`, converts it with `topojson.feature`, and renders it with `d3.geoPath`. The legend uses `d3.scaleThreshold` and `d3.axisBottom`. The map is built with D3 v4 and React in the supporting files.

AAlice Hua

72% match

Loading thumbnail…

Untitled

This visualization displays population density per square mile across U.S. census block groups using a choropleth map. A threshold color scale with d3.schemeOrRd maps density values to sequential red tones, while a legend with a sqrt scale and axis shows the breakpoints. The code loads TopoJSON data via d3.json, renders block group polygons with d3.geoPath, and overlays county boundaries as black outlines. An interactive legend is constructed with rect elements and d3.axisBottom.

CCurran Kelleher

72% match

Loading thumbnail…

Untitled

This choropleth map shows population density per square mile across California counties, using a sequential orange-red color scale with a threshold legend. The visualization loads GeoJSON topology data and renders county boundaries as SVG paths via `d3.geoPath`. Colors are assigned by county ID using `d3.schemeOrRd[9]`, while the legend uses `d3.scaleThreshold` and `d3.axisBottom` to display the value ranges. County outlines are drawn from a separate topology object with a semi-transparent black stroke.

AAlice Hua

72% match

Loading thumbnail…

Untitled

A choropleth map of population density by census block group uses a sequential color scale from the d3-scale-chromatic library to shade geographic regions. The visualization renders as SVG via d3.geoPath, with a threshold scale mapping density values to the OrRd color scheme and a legend using d3.axisBottom. It loads TopoJSON data containing block group polygons, fills each path according to its population per square mile, and outlines counties with a subtle stroke. The code applies d3.scaleThreshold and d3.scaleSqrt to encode the data range.

JJohan van Beusekom

72% match

Loading thumbnail…

U.S. Population Density

This map visualizes U.S. population density by census tract using a choropleth coloring scheme, with darker reds indicating higher people per square mile. It renders static SVG via an HTML image tag, and the map is derived from 2014 American Community Survey data joined with census tract boundaries. The build uses TopoJSON CLI tools (`geo2topo`, `topomerge`, `toposimplify`) and D3 projections (`d3.geoAlbersUsa`), with color bins defined by `d3.schemeOrRd` and a custom legend.

Mmbostock

70% match

Loading thumbnail…

TheNpercent

A choropleth map of U.S. counties lets users adjust a slider to highlight counties whose combined population equals a chosen percentage of the national total. A toggle switches between selecting the most or least populous counties, and another toggle compares density versus a fill based on 2014 population. Built with D3 v3 and TopoJSON, the map uses `d3.geo.path` for SVG rendering and jQuery UI for the slider and toggles, with population data from a CSV file.

BBcohn

70% match

Loading thumbnail…

California Population Density II

A choropleth map of California displays population density per square mile across 23,198 block groups, using a sequential red color scale and a square-root axis legend. Drawn with `d3.geoPath` and SVG, the visualization loads topology from a preprocessed `topo.json` file, created by scripts that download Census block group boundaries and ACS population data via the Census API. The `prepublish` script projects, joins, and simplifies the data using `geo2topo`, `topomerge`, and `topoquantize`. County borders are overlaid as semi-transparent outlines.

Mmbostock

69% match