Skip to content
Kharita Challenges

Problems

Real geospatial problems, graded automatically. Choose a track, a level and what you want to hand in.

2 of 59 problems

Pick one for me
Track
Spatial Analysis6 problemsPostGIS / SQL3 problemsPython3 problemsRemote Sensing1 problemCartography2 problemsWeb GIS1 problemData Management7 problemsGIS Architecture0 problems
Level
Beginner2 problemsIntermediate9 problemsAdvanced5 problemsExpert0 problems
Hand in
SQL0 problemsPython0 problemsGeoJSON1 problemAnswers1 problemSchema0 problemsDecisions0 problemsDataset file0 problems
Category
Data preparation0 problemsData quality0 problemsSpatial analysis0 problemsRaster analysis0 problemsCartography1 problemDecision support0 problemsGeospatial systems0 problemsWeb delivery1 problem
Sign in to track progress
CartographyBeginnerClear all
  1. Not started, How many tiles does an offline London need?Web deliveryAnswers

    From a bounding box to a tile count: size the offline basemap for a field app across zoom 10–15.

    Web GISbeginnerDifficulty: beginner140 XP~25 min3 checks

    You hand in your answers as values.

    Dataset

    • London boroughs · Polygon · 33 features · EPSG:4326

    What you’ll do

    • Take the bounding box of the borough layer
    • Convert box corners to tile coordinates at each zoom
    • Count tiles per zoom and total them into a storage estimate
    XYZ tilesWeb Mercatorofflinecapacity planningLondonAlso trains Cartography
    Open problem
  2. Not started, Normalise the map before you shade itCartographyGeoJSON

    Turn a count into a rate: population per square kilometre for every country, with the area measured rather than looked up.

    CartographybeginnerDifficulty: beginner140 XP~25 min6 checks

    You hand in a GeoJSON result.

    Dataset

    • Countries · MultiPolygon · 241 features · EPSG:4326

    What you’ll do

    • Measure every polygon's area in an equal-area projection
    • Compute a rate by dividing the count by the area
    • Return every country, ready to shade
    choroplethnormalisationEqual EarthdensityglobalAlso trains Spatial Analysis
    Open problem