Home – Home – Jornals – Geography and natural resources 2018 number 1

We explore the possibility of using space images in the study of the distribution of suspended sediments transported by the sediment runoff of the Selenga river, in the southern part of Lake Baikal. The relative concentration of suspended particles was identified on Landsat images without using ground-based turbidity measurements. The effect of different depths of solar radiation penetration was used to separate suspended matter in the surface layer and in deeper layers. On the basis of satellite image interpretation and using data on the constant currents in the lake, the bottom topography, runoff and prevailing winds for the day before the images were taken, we constructed the maps of suspended sediment distribution in the lake. The maps were used to indirectly estimate the sediment runoff distribution in the by-channels of the Selenga river delta depending on the time and phase of the water regime. A number of factors influencing the sediment runoff distribution were identified: the volume of transported material, longshore and deep-water currents, surface currents caused by short-lasting wind effects, and bottom topography. The effect of each factor on the sediment runoff distribution was analyzed. Analysis of the maps confirmed that the main factor in calm weather conditions is represented by constant currents in the lake. However, in the case of significant unidirectional wind effects, the sediment runoff distribution changes drastically. It is established that the pattern of sediment runoff distribution has remained unchanged for at least the last forty years.