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Kharita Challenges
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Two abstract polygon slabs, one stretched tall in teal and one squashed in amber, resting on a balance beam in front of a small blue grid

A world map that tells the truth

The countries layer as a working dataset: what a projection does to area, what normalisation does to a choropleth, what generalisation does to a coastline, and the audits that decide whether the layer can be trusted for the job.

Cartography

Steps
5
Each assumes the one before it
Time
~3 h
At the problems' own estimates
XP
1,100
Before hint costs and speed bonuses
Progress
0/5
Start the pathBegins with How big does Web Mercator make Greenland?

What you will be able to do

Take a global boundary layer and make defensible maps and lists from it: quantify projection distortion, shade a rate rather than a count, audit identifiers and geometry before joining on them, and apply an area rule across borders in an equal-area projection.

The sequence

Each step assumes the one before it.

  1. Up nextHow big does Web Mercator make Greenland?Up nextPut a number on the most famous distortion in cartography: the same countries measured on the ellipsoid and on the projection every web map uses.intermediateDifficulty: intermediate210 XP~30 min
  2. 2Normalise the map before you shade itTurn a count into a rate: population per square kilometre for every country, with the area measured rather than looked up.beginnerDifficulty: beginner140 XP~25 min
  3. 3Which airport codes will break the schedule join?Audit a registry's identifiers before they become a join key: missing, malformed and duplicated codes, and positions that are only approximate.beginnerDifficulty: beginner130 XP~25 min
  4. 4Are these country polygons fit to assign cities to?A point-in-polygon audit that exposes what 1:50m generalisation does to a coastline — and which places the attribute and the geometry disagree about.advancedDifficulty: advanced300 XP~45 min
  5. 5Which metros straddle an international border?Overlay 2,143 urban footprints on 241 countries and keep the ones with real built-up area on both sides of a line.advancedDifficulty: advanced320 XP~50 min

Where it leads

Cartography is examined in the Policy map evidence screen, which issues the Kharita Certified Policy Mapping Analyst (Associate) (KPMA-A1). The problems here are the practice; the assessment is the same kind of problem, under time.