Published on 25 April 2020
The relationship between the nature of the spring flood and the geological history of the drained territories is studied. The main method of research is system analysis. As it was established, the Upper Kolyma catchment area displays both simi-larities in its physico-geographic environments and differences in its geologic histories. Its left side is related to the Inyali-Debin Synclinorium and its right side is related to the Ayan-Yuryak Anticlinorium. The Permian-Mid Jurassic terrigenous sequences of these structures are similar by their composition and were forming in turbidite conditions. Since the upper Jurassic through the lower Cretaceous, when the Indighirka-Omolon Superterrane and the North Asian Craton were interacting, the synclinorium was subject to intense shifting and collisional pressure impacts, which had caused inner defects in rock-forming minerals, whereas in the territory of the Ayan-Yuryak Anticlinorium the same processes were less important.
The results of geologic events, which proceeded in these territories more than 130 000 000 years ago, were that the processes of hydrolysis of silicate and alumosilicate rocks and their alteration to clay minerals had a greater significance in the Inyali-Debin Synclinorium than in the less active anticlinorium area. So, slopes have their debris and gruss soil cover usually consisting of loam and sandy loam rocks. Hypergenic and tectonic fractures have clay infillings. In the early June, depth of thawing is usually less than 10 cm over valley slopes.
Melt and rain water form slope drainage, with its evaporation value 20-30 % greater than in the right-side catchment area. Within the Ayan-Yuryak Anticlinorium area, the rock weathering products are coarser by their fraction; therefore the thawing depth of frozen layer is everywhere more than 20 cm as soon as at the end of May. The slope run-off of melt and rain water transforms into the subsurface drainage type without any significant evaporation and ground saturation loss. Therefore, the Kolyma right-side tributaries have their maximum flow module 20-30 % in average higher than the left tributaries. The paper as well presents other differences in flow parameters as due to peculiar geologic histories of the left-side and right-side territories. Proceeding from all this said above, we conclude that, in order to predict calculation water maximums in high-water seasons, researchers must take into consideration both physiсo-geographic features and area-specific geologic histories.
Tags: Верхняя Колыма, горные реки, криолитозона, геологическая история, половодье, сезонно-талый слой.
ISSN 1998-4502 (Print) ISSN 2499-975Х (Online)