QUANTITATIVE ASSESSMENT OF RELATIONS OF RIVER AND GROUND WATER IN THE MIDDLE OB BASIN (WESTERN SIBERIA)

Abstract

Relevance. Knowledge of the mechanisms and patterns of changes in groundwater flow, the conditions for the interaction of groundwater, river and swamp waters of the Ob river basin, including the Tomsk region, is necessary to predict changes in the region's water resources and plan measures for their integrated use and protection. The aim of the research is quantitative assessment of the interrelations of river and groundwater in the Middle Ob river (Tomsk region) based on the results of determining the ratio of infiltration to the filtration coefficient and the position of groundwater levels on river watersheds. Methods: statistical methods, methods of mathematical modeling. Results and conclusions. The data of long-term hydrological (22 posts on the Ob river and its tributaries) and hydrogeological (14 hydrogeological wells) observations on the territory of the Tomsk region for the period from the 1960s till 2005–2015 were analyzed. It is shown that infiltration generally decreases during floods, and on watersheds it decreases longer and more smoothly than in river valleys. The intra-annual change in the ratio of infiltration to hydraulic conditions in most cases is inversely proportional to the change in the average value of the water flow layer of adjacent rivers. A quantitative assessment of intra-annual changes in the position of river watersheds was made. The most significant changes were found on the border between the rivers: Ob and Vasyugan (well 124p), Ob and Shegarka (63p), Chulym and Kiya (81p). It is concluded that the catchment boundary should be considered not as a line, but as a strip. Quantitative confirmations of regional ground runoff were obtained not only along the rivers, but also in the meridional direction (approximately from south to north).

Keywords

• ground and river waters
• the middle ob river
• infiltration ratio to hydraulic conditions
• water level regime