Topband: Dirt in the way?

[Jon Zaimes AA1K]

They're getting ready to build some new homes next to me, and  the crews 
have been busy moving dirt around as they put in the sewage lines and 
roads. A few days ago I noticed the dirt they have been piling up in a 
mound had grown to about 70 feet high -- and it's right on a line to 
Europe with my 160-meter vertical array. Perhaps 300 feet in front of it.

I wonder if anyone has done terrain analysis on such a mound -- what 
impact it might have on the array? I did notice an SWR change in that 
direction recently but hadn't made any connection to the dirt mound 
until now. The mound will be removed as the development progresses, but 
I'm just curious on any impact in the meantime.

73/Jon AA1K