Problems

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

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PostGIS / SQL Advanced Clear all

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 checksPostGIS / SQLadvancedDifficulty: advanced30045m5
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
Not started, Deliver a compact sewer review mapProjectWeb delivery3 steps
Extract a review cohort, make its browser payload inspectable, and measure the transfer budget.
Web GISadvancedDifficulty: advanced580 XP~90 min9 checksWeb GISadvancedDifficulty: advanced58090m9
Worked in 3 steps, each checked before the next one opens.
Extract the review cohort · SQL
Prepare the browser layer · Python
Measure the transfer budget · Answers
Dataset
NYC 311 sewer requests, 1–7 June 2025 · Point · 408 features · EPSG:4326
What you’ll do
Query the exact review cohort
Serve a compact, inspectable WGS 84 point layer
Measure raw and compressed payload size from the delivered layer
NYC 311urban servicestemporal GISheat mapGeoPandasAlso trains PostGIS / SQL, Python
Open project
Not started, Model event and airfield condition checksGeospatial systemsSchema
Design a PostGIS schema that keeps earthquake events, airfields and repeated condition checks traceable.
Data ManagementadvancedDifficulty: advanced520 XP~85 min12 checksData ManagementadvancedDifficulty: advanced52085m12
You hand in a database schema (DDL).
What you’ll do
Model stable event and airfield identities with timestamped condition observations
Declare point type and WGS 84 SRID at the database boundary
Build spatial and chronological indexes that support the response dashboard
projectPostGISschemadata engineeringemergency responseAlso trains PostGIS / SQL, GIS Architecture
Open problem
Not started, Urban share of each state, in SQLSpatial analysisSQL
ST_Intersection for the pieces and ST_Area on geography for the metres — the overlay-and-measure pattern inside the database.
PostGIS / SQLadvancedDifficulty: advanced300 XP~45 min5 checksPostGIS / SQLadvancedDifficulty: advanced30045m5
You hand in a spatial SQL query.
Datasets
United States states · Polygon · 51 features · EPSG:4326
Urban areas · Polygon · 2,143 features · EPSG:4326
What you’ll do
Overlay polygons with ST_Intersection
Measure the pieces on geography rather than in degrees
Aggregate per state, keeping the states with nothing
ST_IntersectiongeographyoverlayGROUP BYland useAlso trains Spatial Analysis
Open problem
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 checksPostGIS / SQLadvancedDifficulty: advanced39065m8
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
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