la mer caspienne est un bassin isole de type lacustre. son regime sale depend de l'influence de l'eau douce et de l'evaporation de la nappe d'eau. la masse principale des sels vient des bassins qui occupaient son auge au pliocene et au pleistocene. cependant, des la fin du pliocene (i'age apcheron), la mer caspienne formait deja un bassin d'eau saumatre. au cours d...

We consider the problem of numerically approximating the solution of an elliptic partial di erential equation with random coe cients and homogeneous Dirichlet boundary conditions. We focus on the case of a lognormal coe cient, we have then to deal with the lack of uniform coercivity and uniform boundedness with respect to the randomness. This model is frequently used in hydrogeology. We approxi...