  This paper is in the continuity of a work program. Its goal is to develop an
approach of the paralic confinement usable from the modeling slant, before
implementing it in numerical tools. More specifically, we here deal with the
multiscale aspect of the confinement. If a paralic environment is separated
into two (or more) connected areas, we will show that is possible to split the
confinement problem into two related problems, one for each area. At the end of
this paper, we will focus on the importance of the interface length between the
two subdomains.
