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.本实验数据用于研究雨滴击溅对坡面薄层水流阻力特性的影响。水槽长6.0m、宽0.25m、深0.3m，其床面铺设一层均匀光滑的水泥砂浆（砂灰比2:1）。随后在水槽床面上方0.4m处架设尼龙纱布罩以削弱雨滴击溅作用。本实验针对各工况分别开展了4种降雨强度与8种坡度条件下的水槽模拟试验，四种模拟的、对应有纱网与无纱网工况的雨滴特性数据均存放于该文件夹中。实验数据主要包含全水槽的平均流速与水深。采用高锰酸钾（KMnO4）染色示踪法对各段坡面水流流速进行测量。全水槽被均匀划分为三段：下坡段（0~2m）、中段（2~4m）与上坡段（4~6m），并对各段分别测量水流流速与水深。全水槽的平均流速为三段坡面水流流速的平均值。水深测量采用水位测针法，沿水槽每1m间距布设测点；沿水槽中心线共设置6个水深测量测点，分别位于0.5、1.5、2.5、3.5、4.5、5.5m位置处。全水槽的平均水深为所有测点水深测量值的算术平均值。