Перевод названия: FLUXES OF CHEMICAL ELEMENTS FROM CENTRAL SIBERIAN PLATEAU WATERSHEDS, UNDERLAIN BY PERMAFROST
Тип публикации: доклад, тезисы доклада, статья из сборника материалов конференций
Конференция: Enviromis 2016; Томск; Томск
Год издания: 2016
Аннотация: Permafrost distribution on Central Siberian Plateau and dynamics of active layer thawing determine the fed-characteristic of subarctic rivers. During the winter mean water period the greatest contribution in river feed- ing is made by ground water discharged through taliks, during the frost-free period - by precipitation, infiltrating in soil (Prokushkin et al 2011). Climate data analysis indicates that temperature, precipitation and water dis- charge have been increasing during last 50 years for Central Siberian rivers. Our objective was to estimate elements' fluxes (HCO3-, SO42-, Cl-, Ca2+, Mg2+) from the Nizhnyaya Tun- guska river basin (for the period 1970-2011) and from the Tembenchi river basin (for the period 1960-2011). For calculating daily fluxes, we applied the following stages: 1) elements' concentrations were multiplied by water discharges for all available dates; 2) then, we analyzed fluxes (F) dependence on water discharges (Q) for each anion and cation and we found that this dependence could be described by the function F = a × Q b most signifi- cantly ( a and b - coefficients). Confidence levels (p) for a and b were obtained with using STATISTICA 10 and all coefficients for entire period and all anions had necessary reliability (p ≤ 0.05, or p ≥ 95%). Annual ions' fluxes from the Nizhnyaya Tunguska watershed has been increased. In particular, from 1960 to 2011 elements' flows increased : bicarbonate from 2.92 to 12.77 Mg/km2/year, chloride from 0.95 to 11.07 Mg/km2/year, sulfate from 1.13 to 2.79 Mg/km2/year, calcium from 1.48 to Mg/km2/year, magnesium from 0.4 to 1.44 Mg/km2/year). Thus, total flux of the main ions have been risen more than 4.5 times from the Nizhnyaya Tunguska river basin. There are probable causes of this increasing: 1) increasing high latitude rivers' water dis- charges (Peterson et al, 2002); 2) permafrost degradation caused by climate warming (Frey and McClelland, 2009), which may lead to changes in river feeding. Trend of changing in elements' fluxes from the Tembenchi river basin is different from that for Nizhnyaya Tunguska. The flux growth (from 1970 to 2011) was observed for following ions: bicarbonate (from 6.96 to 11.63 Mg/km2/year), calcium (from 2.46 to 4.84 Mg/km2/year) and magnesium (from 0.57 to 0.94 Mg/km2/year). However, the sulfate flux has been decreased from 1.47 to 0.4 Mg/km2/year and chloride flux varied from 1.88 to 3.39 Mg/km2/year without any trend. Nevertheless, the total export of main ions from the Tembenchi watershed increased from 14.45 to 20.37 Mg/km2/year since 1970 to 2011. As previously described, we used two different data sources and some differences in fluxvalues were ob- tained. For example, sulfate flow from the Nizhnyaya Tunguska river basin from 2005 to 2011 changed within - 2.32 Mg/km2/year according to our data, and within 2.36 - 5.43 Mg/km2/year according to ROSHY- DROMET data. Also for Tembenchi sulfate flux had significant decrease from 1.54 Mg/km2/year (1993, ROSHYDROMET data) to 0.54 Mg/km2/year (2005, our data). Such fact may cause by some distinctions in sampling and water analysis.
Журнал: Enviromis 2016
Номера страниц: 246-250
Издатель: Томский центр научно-технической информации