DUTTv2 Automation

Software to automatically import population densities, GTFS feeds and mapping data in order to calculate transport & accessibility inequalities based on isochrones.

Data and Creation Flow

Creation of the necessary data to make calculations is done in the following steps.

Extraction of population rasters which serve as centroids for isochrones.

1. For every GHS Urban Center as specified by 1-data/1-research/cities.xlsx, make an extract from GHS-pop, giving population estimates.
2. Export these to GeoDataFrame Pickles and GeoTIFF files in 3-interim/populationmasks

Setup of isochrone generator in a Graphhopper route-calculator instance.

1. Download OSM map file directly from OpenStreetMap
2. Convert map.osm data to map.osm.pbf using Osmium so it can be read by GraphHopper.
3. Download transit GTFS feed data from https://www.transit.land/documentation/.
4. Update GraphHopper Config file (if necessary)
5. Create Graphhopper instance, wait for it to finish parsing all data.
   1. Comment: profiles and points have a big influence on the outcome of these isochrones.

Go over the grid in the extracted population mask, fetching isochrones from GraphHopper

1. Run loop and cache in cache.db