Mire water balance within the River Klyuch basin, Western Siberia

Examinations of water balance were carried out in the north-eastern part of the Vasyugan mire within the area of the small basin of the River Klyuch. The determination of annual precipitation, snow cover water equivalent, evaporation amount and discharge were conducted separately for every dominant type of the raised bog biogeocenoses, and a monthly water balance model was used. As a result of this research it was noted that differences in the water balance of biogeocenoses are defined by the vegetation structure, which defines the process of moisture accumulation in the bog peat deposit. Statistical analysis of long-term changes in water balance elements allowed us to identify a decrease of overall moistening in April-May, a gradual increase of evaporation in the autumn period, the growing duration of the transitional autumn-winter period and a corresponding reduction of moisture content in snow cover in November-December. As a result, redistribution of the hydrological regime, which is characterized by a definite flow decrease in November, December and April-June, and an increase in August-September is observed in the region. Nevertheless, the annual characteristics of the water balance remain statistically unchanged. Generally, conditions for the development of mire formation and peat accumulation processes owing to excessive moistening in the warm period of year will remain favourable in the nearest and medium term prospect.