I haven't been able to find anything that could comprehensively help me with my problem.
I want to calculate median elevation for UK local authority areas. So far I've taken the OS Terrain 50 data which is available in three formats [ESRI ® Shape (Contours): 1.1 Gb], [GML (Contours): 1.1 Gb], [ASCII Grid and GML (Grid): 162 Mb].
I think I need to intersect the height data with the local authority boundaries, but I'm struggling. There are lots of related questions on OS Terrain 50 such as here, here and here but some of them focus on loading in the data in different formats on other operating systems. I'm on Windows 7 and attempting to do this in QGIS. I have limited Python experience, but I suspect I'm going to have rectify that to solve this problem.
How do I load in the very large number of WinZipped files associated with the OS Terrain 50 and then take the intersection with the local authority boundaries, in order for me to calculate basic statistics on the associated elevation attributes?