Finding sum of points values within distance from paths

Question

I'm willing to plot public transport data for a university project, and I'm currently trying to find out roughly how many people live with a reasonable distance from a set of bus routes.

I have my bus routes set up as paths, like the green path below, and population data per small area as an attribute for each pink point.

What I'm trying to do is create a buffer around each bus route of roughly 1 km, select all the pink points within the buffer area, find the sum of the "Population" value of each, and save that in a file. However, I have around 600 routes I'm trying to find this info for, and I haven't been able to find any way to batch process all of my routes.

Answer 1

If you want to use the whole layer as an input to your analysis, just open the appropriate tool from processing toolbox and select that layer in a corresponding menu. Majority of tools works in a "per feature" manner, so that desired algorithm is applied for each feature in layer (eg cretes buffer around each feature in layer, and so on) So, with that in mind, your analysis is pretty straightforward:

1. run Buffer algorithm for whole bus routes layer with the desired buffer amount.
2. Then run Extract by location algorithm. Ther you want to extract features from population layer that intersects layer resulting from step 1.
3. Then use Basic statistics for fields algorithm co compute statistics for poupulation field in layer from step 2. Or alternatively you can use interactive statistics tool as described here: Sum values in a field for selected features QGIS