Simulating Dynamic of Suspended Sediment Flow Based on Data of Primorskaya Water Balance Station

Abstract

Soil loss rate, suspended load, and suspended sediment discharge were simulated for the drainage basin of the Komarovka R., located at the territory of the former Primorskaya Water Balance, Russian Far East. The study was based on an open-code SWAT model. The model was calibrated and verified using archive measurement data on sediment load and suspended sediment discharge at PWBS by data of Tsentral’nyi hydrological gage (157 km2). The simulation efficiency of the suspended load and suspended sediment discharge corresponds to categories satisfactory and higher. On the average for the drainage basin, the rate of soil washout is 11–12 t/ha per year. The washout rate is maximal in the period of active snow melting. The mean monthly value for April–May is 75 thous. t. The mean annual washout is 171 thous. t, and the maximal is 800 thous. t/year. The mean annual runoff of suspended sediments in the outlet section of the drainage basin is 2.6 thous. t. The highest monthly values of sediment runoff correspond to the period of summer floods in August, when with average of 1 thous. and maximum of 7.7 thous. t. The obtained data on the heterogeneity of the spatial distribution of the simulated values of washout rate are in good agreement with the landscape and climatic features of runoff formation in the drainage river basin. The major errors in the estimation of sediment load are due to the simulation quality of the hydrological regime and dynamics of runoff components that form flood hydrographs.