HYDROGEODYNAMIC AND HYDROGEOCHEMICAL CONDITIONS OF SELF-CLEARANCE OF THE OBSKOE FEN WATER (WESTERN SIBERIA)

• Published in: Bulletin of the Tomsk Polytechnic University Geo Assets Engineering
• Main Authors: Oleg G. Savichev, Yang Heng, Zhou Dan
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: Tomsk Polytechnic University 2022
• Subjects: mathematical modeling; chemical composition; peat deposit; fen waters; the obskoe fen; western siberia; Engineering geology. Rock mechanics. Soil mechanics. Underground construction; TA703-712; ob river; Siberia
• Online Access: https://doi.org/10.18799/24131830/2022/4/3656; https://doaj.org/article/541cd1fbc09646fe8b21342775bea726

Relevance. Economic activity in the wetlands of Western Siberia in the conditions of climate change requires scientific justification of both methods of environmental monitoring and environmental protection measures. One of the effective ways of such justification, taking into account the lack of observations, is mathematical modeling of hydrogeodynamical and hydrogeochemical processes in fen ecosystems. The aim of the research is to identify the mechanisms of natural-technogenic distribution of Cl–-concentrations in water extracts from peat over the depth of peat deposits. Methods: field experiment, methods of definition of a chemical composition of peat and water, methods of mathematical modeling. Results and conclusions. An experiment was conducted to study the self-purification of the eutrophic Obskoe fen in the south of the Tomsk region (release of 50 liters of NaCl solution with a concentration of 20 g/dm3 to the fen surface), and the nature of changes in Cl–-concentrations in peat deposits before and after the release of the solution was established. To explain the revealed facts, mathematical models of the water and geochemical regime of the peat fen site were developed and tested. As a result, it is shown that: 1) fen waters form a common flow with groundwater towards the Ob river; periodic fluctuations in groundwater pressure are possible at the border of the fen; 2) in the lower part of the peat deposit, a local water barrier has formed in the study area, preventing the spread of substances in a peat deposit; 3) distribution of the indicator (Cl–) over the peat deposit largely depends not only on the initial volume and concentration of NaCl and the presence of a water barrier, but also on the nature of the wetness of the fen. Recommendations on the use of simulation results are given.