Specificity of the river flow formation of small mountain streams of the Baikal Natural Territory resulting from wildfires

Abstract

In recent years, a catastrophic situation has arisen in the Baikal natural area associated with forest fires. In 2015-2017, there were catastrophic forest fires. In the work, the key sites of the western coast of the Lake Baikal, which were the most suffered from the fires of 2015-2017, are considered. We studied the most suffered from the fires watersheds of the Yator, Ulan-Khan and Elokhin streams. The results based on modern hydrological and hydrochemical monitoring is discussed. The modern measuring complexes RAP-G-01 (IMKES, Tomsk) are used. Its automatically register the elements of the water regime (water level, conductivity and temperature) every 30 minutes. The chemical composition of water samples after forest fires recorded significant differences from background streams. Changes in the chemical composition of the rivers water take place after the forest fires: the concentrations of nitrates, nitrites, phosphates, and bicarbonates increase; the transfer of water from the hydrocarbonate to the sulphate class of the calcium group is noted. At the pyrogenically disturbed watersheds, the temperature regime of the water changes due to an increase in daytime temperatures and differences between daytime and nighttime temperatures, the mineralization regime is not stable, and the amplitudes of level fluctuations are higher.