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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.

4 of 59 problems

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Track
Spatial Analysis4 problemsPostGIS / SQL4 problemsPython2 problemsRemote Sensing0 problemsCartography2 problemsWeb GIS1 problemData Management4 problemsGIS Architecture1 problem
Level
Beginner1 problemIntermediate2 problemsAdvanced4 problemsExpert0 problems
Hand in
SQL4 problemsPython4 problemsGeoJSON8 problemsAnswers5 problemsSchema1 problemDecisions2 problemsDataset file4 problems
Category
Data preparation0 problemsData quality1 problemSpatial analysis0 problemsRaster analysis0 problemsCartography0 problemsDecision support3 problemsGeospatial systems0 problemsWeb delivery0 problems
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Data ManagementAdvancedSQLClear all
  1. Not started, Are these country polygons fit to assign cities to?Data qualitySQL

    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.

    PostGIS / SQLadvancedDifficulty: advanced300 XP~45 min5 checks

    You hand in a spatial SQL query.

    Datasets

    • Populated places · Point · 1,251 features · EPSG:4326
    • Countries · MultiPolygon · 241 features · EPSG:4326

    What you’ll do

    • Join points to the polygon containing them with an outer join
    • Compare an attribute to a derived value with NULL-safe semantics
    • Return the disagreement list, including the points nothing contains
    ST_Containsouter joinIS DISTINCT FROMgeneralisationdata qualityAlso trains Data Management
    Open problem
  2. Not started, Build an earthquake contact reconnaissance queueProjectDecision support3 steps

    Screen strong shallow events, quantify airfield and settlement proximity, and hand over a traceable contact map.

    Spatial AnalysisadvancedDifficulty: advanced550 XP~95 min12 checks

    Worked in 3 steps, each checked before the next one opens.

    1. Select the event queue · SQL
    2. Measure contact gaps · Answers
    3. Hand over the access map · Python

    Datasets

    • Global M5.5+ earthquakes, Jan–Mar 2025 · Point · 86 features · EPSG:4326
    • World airports · Point · 893 features · EPSG:4326
    • Populated places · Point · 1,251 features · EPSG:4326

    What you’ll do

    • Select a reproducible event queue in SQL
    • Measure two independent global proximity indicators
    • Deliver an auditable access map with an explicit contact-gap distinction
    projectUSGSnearest neighbourlogisticsglobalAlso trains Python, Data Management, Cartography
    Open project
  3. Not started, Plan a cycle redistribution shiftProjectDecision support3 steps

    Classify the dock snapshot, propose bounded bike moves, and size the resulting shift with its unserved stations visible.

    Spatial AnalysisadvancedDifficulty: advanced600 XP~100 min11 checks

    Worked in 3 steps, each checked before the next one opens.

    1. Classify the snapshot · SQL
    2. Map feasible transfers · GeoJSON
    3. Size the preliminary shift · Answers

    Dataset

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

    What you’ll do

    • Classify full and empty active stations in SQL
    • Build a bounded nearest-source transfer map
    • Size a shift and report unserved empties from the same rules
    nearest neighbouroperationscapacityCRStransportLondonAlso trains Data Management, GIS Architecture
    Open project
  4. Not started, Which neighborhoods merit a service follow-up?Decision supportSQL

    Join geocoded service requests to neighborhood polygons and map a review share only where the sample supports it.

    PostGIS / SQLadvancedDifficulty: advanced390 XP~65 min8 checks

    You hand in a spatial SQL query.

    Datasets

    • 2020 Neighborhood Tabulation Areas · MultiPolygon · 262 features · EPSG:4326
    • NYC 311 sewer requests, 1–7 June 2025 · Point · 408 features · EPSG:4326

    What you’ll do

    • Join incident locations to neighborhoods with a boundary-inclusive predicate
    • Compute elapsed-time review share with a clear denominator
    • Suppress very small denominator areas before mapping percentages
    NYC 311PostGISspatial joinservice operationsgraduated mapAlso trains Spatial Analysis, Cartography, Data Management
    Open problem