I think it is possible to do so.
- at the site, shot the image and record the lighting condition (or can look at the pic later)
- in studio, set up a similar site (small, of course) with the rock, water and a green bed.
- ask the bride to lie down as in the image, set up the lighting to match the scenery, and move the camera to a relatively similar, and shot
I think if the studio provide this kind of shot for every wedding, they probably can set up this kind of scenary in the studio and photoshop it. As long as lighting condition and camera angles are similar, this is not a problem
No offense, but doesn't it seem a little tacky copying another photographer's work wholesale? Why not just ask the photographer who originally shot it to do the shoot for your or the DI work or whatever and pay that guy. Seems like it would make more sense on a whole lot of fronts.
The tricky part is the gown that is submerged in the water. You have to make it taking on the colour of the water. And you have to make it flowing in the water with blurring, smudging, distorting and maybe liquidfying.
A conceptually interesting and technically challenging image.