Location & accessibility
Catchments, access to services, gravity models, site suitability and choosing where the next facility should go.
Everything on Spatial Workflow about location & accessibility, in the order that usually works: understand the idea, then run the task, then fix it when it goes wrong. 20 guides in total.
One learning path runs through this topic — follow it if you would rather work through a route than pick a single guide.
🧭 Start with the concepts
The ideas the how-to guides below assume you already have.
- Location Analysis Explained: Catchments, Accessibility and Site Selection location analysis gis explained
- Catchment Areas Explained: Buffers, Isochrones and Voronoi Compared catchment area gis
- Accessibility Measures Explained: Nearest, Cumulative and Gravity spatial accessibility measures
- Gravity and Huff Models Explained: Predicting Where People Go huff model explained
- Site Suitability Explained: Constraints, Factors and Weights site suitability analysis gis
- Location-Allocation Explained: p-Median, Coverage and What Each Optimises location allocation p-median explained
⚙️ Then do the task
Step-by-step walkthroughs with code you can copy and adapt.
- How to Build Voronoi Service Areas Around Facilities in Python voronoi polygons python geopandas
- How to Count the Population Within Reach of Each Facility population within distance of facility python
- How to Measure Distance to the Nearest Facility for Every Home distance to nearest facility python
- How to Measure Access to Services with the Two-Step Floating Catchment Method 2sfca python
- How to Estimate Market Share with a Huff Model in Python huff model python
- How to Run a Weighted Site Suitability Analysis in Python suitability analysis python raster
- How to Choose Facility Locations with a p-Median Model in Python p-median python pulp
- How to Maximise Coverage with a Limited Number of Sites maximal covering location problem python
- How to Find the Areas Nobody Can Reach Within a Travel Time service area coverage gaps python
🔧 When it breaks
The errors this topic produces, with the cause explained rather than just the command.
- Fixing Voronoi Polygons That Extend Forever or Miss the Study Area voronoi polygons infinite python
- Fixing a Location-Allocation Model That Never Solves pulp p-median slow
- Fixing Accessibility Scores That Are Wrong Near the Study Area Edge accessibility edge effect
- Fixing a Gravity Model That Sends Everyone to the Biggest Store huff model distance decay parameter
- Fixing a Suitability Map That Comes Out All One Value or All NoData suitability raster overlay nodata
Learning paths through this topic
A curated route rather than a list — the guides in the order that builds on itself.
Related topics
Subjects that keep coming up alongside this one, most overlap first.