Hi, I was just wondering if say my opponent has Land Equilibrium out then I cast something like Dowsing Dagger and transform it does Land equilibrium trigger on the transformation to Lost Vale?
No. For the purposes of Land Equilibrium, transforming a permanent into a land is not the same as putting a land onto the battlefield (see also C.R. 711.14). (Note that Land Equilibrium's ability is not a triggered ability, since it doesn't have "when", "whenever", or "at" in its Oracle text [C.R. 603.1, 108.1].)
Land Equilibrium and Transform