Changing in Water-physical Properties of Drained Peat Soils during Extraction and Exploration of Minerals in the Conditions of the Northern Urals

Results of long-term (1976-2016) researches of water-physical properties of long seasonally-permafrost peat soils of Northern Trans-Urals are stated. It is shown that the shrinkage process has a significant impact on the density of peat soil, especially in the first years after drainage. In the Northern Urals, the annual decrease in the size of peat soil is 1.5 cm in the first five years after drainage, 1-1.2 cm - for 15 years and 0.6-0.7 cm - in subsequent years. In the first five years after drainage, the density of the 0.2 m layer increases by 7.4%, decreasing to 2.1-3.0% in subsequent years. At a depth of 0.6-1.0 m, 5 years after drainage, there are no significant changes in the addition density. A significant increase in the addition density of peaty - gley soil established by plowing the underlying mineral soil. A relatively stable indicator is the density of the solid phase of the soil. For 35 years, the density of the solid phase of the average peat soil in the 0.3 m layer increased by 5.4%; low - power for 20 years - increased by 1.2%. The lowest moisture content of the average peat soil for the 35-year period in the root (0.3 m) layer decreased by 11.5%; at a depth of 0.6 – 1.0 m – by 3.7%. In low-power peat soil reduction of moisture capacity in the 0.3 m layer for 20 years was 6.4%; in peat (0.2 m) layer of peaty - gley soil for the same period – by 10.2%.