Abstract:As a kind of special landform unit, engineering accumulation is an important source of soil erosion. To explore effects of hedgerows on sediment particles fractal dimension on hillslope, and the runoff and sediment reduction effects of engineering measures, the field pouring water scouring experiments were designed for different inflow rates (35L/min, 45L/min and 55L/min) and slopes (24°, 28° and 32°) in six normal runoff plots (20m×5m). The results showed that the lagged time of initial runoff of hedgerow plots was 100~500s, and the runoff rate and sediment yield rate were less than those of the control plot. Runoff rate rose for intermittent fluctuations in time scale compared with the control plot. Hedgerow reduced the flow rate by 4%~60%, and decreased the rate of sediment by 15%~50%. Significant power function relationships of runoff and sediment reduction rate with slope and flow rate were observed, and the effect of sediment reduction was better than that of runoff reduction rate equation. Runoff sediment was dominant with silt particle, followed by clay. Compared with the control plot, the volume percentage of sand particle in sediment of the hedgerow plots was reduced. In contrast, the volume percentage of clay and silt was increased. Hedgerow plots clay enrichment rate was higher than those in the control plot, and the sand accumulation rate was less than the control plot. The fractal dimension of the hedgerow plots was bigger than that in control plots. The relationships between fractal dimension and the volume fraction of clay and sand were available for better fitting linear model, and fractal dimension of sediment erosion was mainly determined by the volume fraction of clay. The research results could provide some basic data for establishing the model of soil erosion of engineering measures under the condition of accumulation, and provide a theoretical reference for the optimal allocation to hedgerow slope.
