Downslope wash-scour erosion driven by upslope inflow from compacted platform plays an important role in the acceleration of water and soil loss from engineered landforms. To explore the quantitative effects of variable upslope runoff on downslope runoff and erosion, a typical abandoned spoil deposit derived from the construction of Shenfu Expressway was selected to conduct a set of field runoff scouring experiments on steep slope (72.7 %). Four types of upslope inflow rate patterns including constant inflow rate pattern and earlier, intermediately, as well as later peak inflow rate patterns were designed dependent on different rainfall patterns and the timing for peak inflow rate (total inflow amount was kept constant). Thus, the downslope runoff and erosion response of the selected abandoned spoil deposit under variable upslope inflow conditions were investigated, and the results reveal that: (i) Maximum peak runoff intensity and the timing for the maxima were greatly impacted by upslope inflow rate patterns; however, little impact was exerted on total surface runoff; total runoff from the inflow events with earlier, later, and intermediately peak inflow rate increased by 20.6, 11.7, and 8.5 % in comparison with that