Point to polygon walking distance

Question

I do a research on urban park accessibility. I am working with QGIS 3.4 and ORS-Tools for the distance calculation by foot. A use of ArcGIS is possible.

I use a point layer with geocoded apartements and a few polygon layers representing the parks.

I would like to calculate the walking distance with OpenRouteService (ORS-Tool) to the edge of the nearest park polygon. My latest research results concerning distance point to polygon have always led to the use oft the NNJOIN-Tool, which only calculates the euclidean distance to the nearest polygon.

My first attempt was to calculate the distance between the polygon centroids, representing the park and the apartments. After that I did a query (statistics by category) to filter the shortest distance. But for my research goal I need the distance to the egde of the closest polygon.

Answer 1

Convert your polygon boundaries to points. Calculate the distance from each apartment to the nearest point

1. Use the Densify tool to add more vertices along the edges of your polygons.
2. Use the Extract Vertices tool to extract the vertices to a point layer.
3. Run your distance calculations using the vertex layer instead of the park polygons.