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Kharita Challenges

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

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Spatial Analysis1 problemPostGIS / SQL3 problemsPython0 problemsRemote Sensing0 problemsCartography0 problemsWeb GIS0 problemsData Management1 problemGIS Architecture0 problems
Level
Beginner3 problemsIntermediate5 problemsAdvanced6 problemsExpert0 problems
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SQL3 problemsPython2 problemsGeoJSON3 problemsAnswers3 problemsSchema0 problemsDecisions0 problemsDataset file1 problem
Category
Data preparation1 problemData quality0 problemsSpatial analysis2 problemsRaster analysis0 problemsCartography0 problemsDecision support0 problemsGeospatial systems0 problemsWeb delivery0 problems
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BeginnerSQLClear all
  1. Not started, Can the cycle parking feed report real capacity?Data preparationSQL

    Clean a Berlin cycle parking staging table for an operations map and capacity rollup.

    Data ManagementbeginnerDifficulty: beginner130 XP~25 min7 checks

    You hand in a spatial SQL query.

    Dataset

    • Berlin bicycle parking capacity staging · Point · 27 features · EPSG:4326

    What you’ll do

    • Resolve source precedence before casting.
    • Keep unknown capacity distinct from zero.
    • Return geometry for the operational map.
    data-preparationberlinsqlAlso trains PostGIS / SQL
    Open problem
  2. Not started, Docks and bikes per borough, in one querySpatial analysisSQL

    A point-in-polygon join with GROUP BY — and the outer join that keeps the boroughs with nothing to count.

    PostGIS / SQLbeginnerDifficulty: beginner150 XP~25 min4 checks

    You hand in a spatial SQL query.

    Datasets

    • London boroughs · Polygon · 33 features · EPSG:4326
    • Santander Cycles docking stations (live snapshot) · Point · 799 features · EPSG:4326

    What you’ll do

    • Join stations to boroughs with a spatial predicate
    • Aggregate per borough
    • Keep every borough, including the ones outside the scheme
    ST_ContainsGROUP BYouter jointransportLondonAlso trains Spatial Analysis
    Open problem
  3. Not started, How many mapped rivers touch each country?Spatial analysisSQL

    ST_Intersects between lines and polygons with GROUP BY — and the outer join that keeps the countries with none.

    PostGIS / SQLbeginnerDifficulty: beginner150 XP~25 min4 checks

    You hand in a spatial SQL query.

    Datasets

    • Countries · MultiPolygon · 241 features · EPSG:4326
    • Rivers and lake centrelines · LineString · 461 features · EPSG:4326

    What you’ll do

    • Join lines to polygons with a spatial predicate
    • Aggregate per polygon
    • Keep every polygon, including those with no match
    ST_IntersectsGROUP BYouter joinhydrologyglobal
    Open problem