THE ROLE OF CLIMATE AND URBANIZATION IN THE DYNAMICS OF CHANNEL PROCESSES AND GEOCHEMICAL FLOWS IN THE AMUR RIVER

Abstract

It is shown that the increase in the frequency and intensity of extreme floods, as well as the activity of riverbed processes, are associated with global climate change and increased environmental management in the Amur River basin. Their influence has contributed to the transformation of geochemical cycles of trace elements in river runoff. Water turbidity and the distribution of heavy metal concentrations in the riverbed cross-section are determined by the morphological features of the channel, the proximity of pollution sources, and varying flow turbulence during different phases of the water regime. An increase in heavy metal concentrations in the upper layer of bottom sediments was revealed during the low-water period compared to the flood period. High water mineralization in the riverbed during floods is associated with the phenomenon of resuspension. The mechanisms and the relationship of these events with river water content are described. Geochemical series of metals and the characteristics of migration flows in the Amur River channel are characterized. It is established that channel processes and flow turbulence play a primary role in the distribution of pollutants.