A New Hydrological Method for Estimating the River Bed and Drainage Basin Components of Erosion and Suspended Sediment Fluxes in River Basins

This paper uses the results of river suspended sediment flux (SSF) analysis to propose a new hydrological method for quantitatively estimating the river bed and drainage basin (sheet erosion, rill and gully erosion) components of total erosion intensity in river basins. The suggested method is based on the establishment of the functional power connection between mean monthly water discharges (WD, Q i) and suspended sediment fluxes (r i) calculated for the low-water-discharge phases of a river’s hydrological regime in various (on mean annual water discharges) years: r i = a×Q i (where a, ì are some empirical coefficients), and further extrapolation of this connection for other phases of the hydrological regime. Thus, the extrapolation allows us to calculate (in a long-term annual SSF) the proportions of sediments originating in river beds and drainage basins. The proposed method is tested using a long-term (not less than 10 years) series of observations for WD and SSF of 124 chiefly small and midsize rivers of the East-European plain, the Urals, the Eastern Carpathians, the Ciscaucasia and the Caucasus, and Central Asian mountains, containing data on the mean monthly values of WD and SSF. The paper also compares the method with other methods for estimating the components of erosion intensity and SSF.