Abstract

Bottom sediment including technogenous one appears to be geo-chemical «memory» of aquatic object. If natural bottom sediment is attractive as an essential source of information on the character and intensity of the processes determining the chemical discharge from the catchment area over the preceding period, then technogenous sediment could in addition, appear to be significant and in some cases even dominating factor determining the ecological trouble for the aquatic objects. Long-term accumulation of heterophase non-conservative pollutants therein under the definable hydrological and hydro-chemical conditions results in their becoming a potent source of reentering the aquatic body.

From ecological point of view most dangerous appears to be «burst-like» efflux of the pollutants from the bottom sediment that determines the increase in the content of contaminating substances in natural water channel by dozens or even hundreds of times. Such emissions could be observed both at high expenditures of water within a period of rise in spring floods and in the deep low-flow winter period. Both general models of pollutant migration in the system <<water> « <suspended silt> « <bottom sediment>> and single particular models are being considered in the given work while focusing special attention on the description of the processes of the formation of «burst-like» efflux.