Sediment concentration mapping in Siberian rivers (a case study of the Lena River basin)
S.R. CHALOV, D.V. MAGRITSKY, E.A. FINGERT
Lomonosov Moscow State University, Moscow, Russia
Keywords: river, water and sediment runoff, hydrological observations, history of research, GIS, maps
Abstract
This paper examines a methodology for creating a map of average water suspended sediment concentration (SSC) using rivers in the Lena River basin as an example. This method combines actual observation data from gauges, their spatial interpolation, and multivariate relationships with 69 catchment areas. The paper presents the results of a detailed analysis of the initial sediment runoff data, their consistency with long-term fluctuations in river water content, their reliability and completeness, anthropogenic disturbances in the homogeneity of the series, and other factors that affect the reliability of mapping, as well as the choice of the averaging period. In total, the Lena River basin has 96 stations with sediment runoff data for at least one year. Average water SSC characteristics are presented (on a traditional map) as point data in nine gradations. The modeled water SSC map is based on statistical relationships between average water SSC at 53 stations for the period 1978-2021 and 69 factors of its formation, assessed for their catchments in a GIS environment. Generalized for 697 small and medium-sized river catchments and based on six areal gradations of water SSC, the map represents a qualitatively new approach to water SSC mapping in terms of spatial detail. The maps reveal the main spatial patterns of average water SSC distribution and its key factors in the Lena River basin (mountainous areas and mining activities) and characterize the decrease in river SSC compared to maps from the second half of the 20th century.
|
