Intersection between two layers extremely slow

Question

For a project, we have the following layers:

• Multiple layers representing the 4G network coverage for the whole Switzerland
• Multiple layers representing different geographic areas of the country.
• One point layer with about 300 000 points representing the population at these points with the format X_Coord, Y_Coord, population

I have to compute the following calculation:

1. Intersect the 4G coverage layers with all the geographic areas layers to compute the percentage of area covered
2. Intersect the population layer with the result of 1. to compute the percentage of the population covered

To do this task I use MapInfo Pro V16 with a Map Basic script with the folowing function:

• Object intersects into target (for the coverage layer)
• Select sum(population) From CovLayer,Poplayer where CovLayer.obj Intersects PopLayer.obj into selection (For the population layer)

This procedure works but it takes a huge amount of time to compute (about 4 weeks for all the layers). Is there a way to do it faster?

I also tried with QGIS. It seems to be faster to compute the intersection with the geoprocessing Tools > Intersection but it's then much slower to execute the SQL query for the population.

Answer 1

Thank you for you replies. The way to convert the polygon layers to raster seems to be the best solution. We lose a little bit of exactitude due to the rasterization but it's much faster.

To do the rasterization, I used the python library Geocube and numpy and xarray to compute the data.