I'm trying to compute the area of green surface for cities with QGis from open data found online. I have polygons on a layer for the cities boundaries and polygons on another layer for the parks.
I first decided to clip the polygons of the parks but as the boundaries of the cities are adjacent, the parks are not cut along the boundaries.
I then chose to intersect both layers as it would cut the parks alongside the boundaries. But the result is empty! Any clue?
I've already checked the CSR which are the same for both layers.
For example, in this picture, there are two parks (North one foret communale du canton du Cerisier and South one foret communale) and two cities (376 West and 519 East). As the limits of the parks are not the same as the ones of the cities, it should return 4 green areas: two for the North forest (one for each city) and two for the South forest (one for each city).
Here are the files I'm using: https://files.fm/f/cpuyqu2f.
Edit: Seems like the problem comes from park layer. I tried with new layers and the polygons intersection works.