Express-Diagnostics of the Water Sources of a Small Arctic River by the Results of Short-Time Hydrological Survey, Chaunskaya Lowland, Chukotka

Abstract

The article gives the results of generalization of a short-time expedition hydrological–hydrochemical survey in an arctic river basin in the northeastern part of Chaunskaya Lowland in the northern Chukotka, carried out in July 2020. At a scale of a small Yanranaivaam River basin, the structure of water masses was analyzed, and the catchments of individual tributaries with intense development of cryogenic processes were identified; these processes have an effect on water chemistry, in particular, in a higher concentration of hydrocarbonate ions, dissolved ferrum, and dissolved organic carbon. Two-tracer mixing model was used to identify and evaluate the contributions of water sources and their spatial relationships at the moment of survey. The main river water sources are atmospheric waters (mostly snowmelt water), slope soil water of the seasonally thawed layer (STL), and melt water of bald-mountain ice. The dominating water source in the catchments of the middle and upper parts of the basin is atmospheric water (67–78%), and that in the catchments of the lower part of the basin is STL soil water (59–64%). River recharge by meltwater of bald-mountain ice is typical of the entire basin, and at the moment of survey it accounted for 10–14% of the total.