The Influence of Prolonged Floodings on a Soil Cover of the Alazeya River Basin

Ivanova A.Z., Desyatkin R.V.

A detailed soil research connecting with investigation of consequences of the catastrophic flood flows on the Alaseya River valley in 2008-2009 years was conducted for the first time. In this article materials on identifying of the impact of prolonged floods on a river valley soils are presented, and selection of soil degradation stages is substantiated. Hydromorphic soil transformation was evaluated on the basis of changes of the morphological structure of disturbed soils, basic physical and chemical properties of the studied soils were analyzed. As a result of the fulfilled works it was revealed three stages of soil disturbance: the first stage of soil degradation is characterized by impaired water regime  caused by  strong waterlogging and changing of thawing depth; the second stage is characterized by a deep disturbance of a surface humus horizon and partial destructurization of the mineral part of a profile; signs of the third stage of disturbance are the accumulation of fresh alluvium, degradation of organic horizon and full destructurization of a mineral layer and as a result a total change of the soil profile structure. Thus it was found that floods in a permafrost region, first of all, have a mechanical effect on the soil, breaking their natural morphological structure, water regime, etc., which leads to disruption of the bufferness of the system, reducing of fertility and even to waterlogging of the territories.

Key words: flood inundation, soil cover, degradation stages, cryosol.

Science and Education, 2015, No.1, pp.87-93