How do I calculate average depth of a 250m square using points at 125m spacing using QGIS

Question

I have a set of points spaced at 125m intervals across an area, an average depth value is assigned to each point.

I need to calculate from these points a single average depth value for a 250m square, I started doing this manually but there are 220 points, and would take a long time to do.

I was wondering if there is a tool in QGIS that I could use to achieve this?

Answer 1

1. Make a .shp rectangle with 250X250 extent. You can use the advanced digitizing Toolbox for that
2. Select all the points inside the rectangle: Vector -> Research Tools -> Select by Location
3. Activate the Statistics Panel: View -> Panels -> Statistics
4. Select the point layer and your depth field and thick selected features only. Now you see the mean value of your deapths in the 250 m2 rectangle.