Аннотация:The paper is devoted to the study of the formation of stratification in an incompressible fluid due to convective laminar flows in horizontal layers heated from the side. Medium and intensive modes of stationary laminar thermal, concentrational and thermoconcentrational (in particular thermohaline) convection are considered, in which nonlinear flowfeatures are manifested, which can radically change the flow structure and the characteristics ofheat and mass transfer. The solutions of the problems of laminar problems of convection showthe features of the formation of layered structures, vertical temperature and concentrationstratification depending on the determining dimensionless parameters. The metastableinstability of the direction of the stratification vector (the location of the free surface) inweightlessness in the presence of capillary convection was shown.