nappe d'accompagnement

17:13 Jan 11, 2010 

of a given permeability, the water table will remain more stable, any change in level occurring less quickly and less steeply, such that it could be said, at that point, not to "accompany" the river at all.

17:11 Jan 11, 2010 

It's not a term I'm familiar with, and I'm far from sure it's a type of aquifer. Rather a part of an unconfined aquifer or "floodplain water table" as Guy has suggested, i.e. that more or less large area to the sides of the river which reacts more or less promptly to variations in river flow, and vice versa, depending on the permeability of the ground. I'd say practically all rivers feed and/or are fed by immediately adjacent groundwater, in addition to being fed by immediate surface runoff and springs. Such groundwater is an unconfined aquifer, i.e. not confined by an impermeable stratum above, and hence forming the water table (the top surface of an unconfined aquifer). Although such an unconfined aquifer might be said to "accompany" a river or rivers that flow above and through it, only the parts closest to the river will interact with and fully accompagner it, rising when the river rises, falling when the river falls (causing a linear "cone of depression" along the river and potentially separating from the river), but also causing the river to rise when it rises or to fall when it falls. At greater distances from the river, for a soil of a given permeabilit

16:51 Jan 11, 2010 

Hi Chris, I don't think so, since the text is definitely talking about ground water (surface water is covered in the following section), so I'm not sure "sheet of water" is specific enough...

16:41 Jan 11, 2010 

Can it not simply be translated as "accompanying sheet of water"?