Evolution of Suspended Sediment Budget in the Deltas of Lake Baikal Tributaries

Abstract

The monitoring, field, and satellite datasets are used to estimate changes in suspended sediment budget for the Selenga and Upper Angara river deltas. Sediment deficit during recent decades dominates delta evolution due to decrease in the sediment delivery to the delta since the middle of the 1970s by 51% for the Selenga River and by 70% for the Upper Angara River. The observed decline in the sediment runoff and peak water flows associated with the sediment deposition within the inundated flood-plain of the deltas leads to the reduction of the sediment aggradation rates over both deltas. Under low water flows we observed longitudinal increase of the sediment transport rates along Selenga River delta; the Upper Angara constantly reduces sediment transport rates under various hydrological conditions.