I attach an example to illustrate my query.

Why is it that textures change so dramatically when applied to a displacement, as opposed to a brush? Is there a way to avoid this happening?

I can understand that the shading of the texture would change according to the shape, but it seems that something more artificial is occurring, e.g. in the attached image we see the 'grid' of the texture dramatically more pronounced.

Sorry if this is an obvious question - I tried searching to no avail.

Use a decal/overlay not a custom texture to apply on a displacement. Any texture ready to place on a displacement should start with nature/ or have 'blend' in it.

Thanks for the reply, however the texture I am using is in fact 'nature/blendwhitefloor_dirt01'.

On compiling I do see the error:

Patching WVT material: maps/mapname/nature/blendwhitefloor_dirt01_wvt_patch

blend textures consist of two parts: if you use the texture normally you have texture #1, if you're using a displacement you're using #2.
Changing the alpha will calculate a blended version of texture one and two. Fiddle around with this a bit and you can make it look really nice.
If you just want the normal texture invert alpha should work!

Thanks for the reply. I want it to look the same as the surrounding (non-displacement) texture, so I tried inverting the alpha. However, this had the following effect: (!)

Managed to solve this by actually doing the opposite of what was suggested - by not using a texture with 'nature' or 'blend' in, it actually looks correct.