Effects of Raindrop Impact on the Resistance Characteristics of Sheet Flow

The experimental data were used to study effects of raindrop impact on the resistance characteristics of sheet flow. The flume was 6.0 m long, 0.25 m wide, and 0.3 m deep. The bed surface of the flume was covered by a smooth and uniform layer of mortar (sand to cement mixing ratio 2:1). The flume surface was then sheltered with a nylon gauze sheet, which was fixed at 0.4 m above the flume surface to reduce the raindrop impact. Flume tests with four rainfall intensities and eight slope angles were simulated for each scenario. The four simulated raindrop characteristics of with and without gauze screen are located in the folder. The experimental data mainly include mean flow velocity and depth of whole flume. The surface flow velocity was measured in each segment by using a dye tracing method with KMnO4. The whole flume was equally divided into three segments: downslope (0-2 m), middle slope (2-4 m) and upslope (4-6 m). The surface flow velocity and flow depth were measured in each segment. The surface velocity of the whole flume was mean surface velocity of the three segments. Flow depth was measured in each 1 m by using a water level measuring needle. There were six observation points for measuring flow depth, positioned at 0.5, 1.5, 2.5, 3.5, 4.5, 5.5 m along the flume center line. The mean flow depth of the whole flume was the average of all measured points