Data from: Sediment transport and bed topography for realistic unsteady flow hydrographs of varying length in a laboratory flume

This is the dataset that was used to make the figures for the publication entitled "Sediment transport and bed topography for realistic unsteady flow hydrographs of varying length in a laboratory flume."The citation for the publication is: Wren, D. G., Kuhnle, R. A., McAlpin, T. O., Langendoen, E. L. Sediment transport and bed topography for realistic unsteady flow hydrographs of varying length in a laboratory flume. Journal of Hydraulic Engineering. 10.1061/JHEND8/HYENG-13769How the dataset was generated: Experiments were conducted at the USDA-ARS National Sedimentation Laboratory in a 30-meters long x 1.22-meters wide x 0.61-meter-deep flume channel with a frequency-controlled pump motor and adjustable slope. The sand for the bed was purchased from a local source and had a median particle size of 0.43 mm. The bed load transport rate was measured by a Sedflux system that operated at 1 Hz (Hertz, cycles per second) using two drums suspended from load cells over 1.2 meters wide by 0.57 meters long sediment trap that was 28.5 meters from the channel origin. The mass of sand accumulated in the drums was recorded continuously, and the drums were dumped after the mass of sediment reached 30 kilograms. After leaving the drums, the sand particles were circulated through a 0.152-meter diameter pipeline and re-entered the flume at the upstream end. Material that bypassed the trap entered the main return pipe and was sampled from the center of the return pipe just downstream of the pump impellor using a 10.6-millimeter diameter sampling nozzle. Flow velocity into the nozzle was matched to the mean return line flow velocity to avoid biasing the concentration measurements. Discharge in the sampling line was checked by measuring the mass of water accumulated over time. Sediment-laden water was passed through a 0.062 mm sieve that retained sand particles and allowed the water to return to the flume channel. The mean sediment concentration from the physical samples was used to calculate the load that bypassed the Sedflux system. Bed surface elevations were measured acoustically at a rate of 10 Hertz using 32 transducers with an acoustic frequency of 5-million cycles per second, fired sequentially. The transducers were spaced at 3.7-centimeter intervals in a PVC bar with a blunt face and narrow trailing edge to minimize flow separation and drag. The transducers were held at a constant distance from the bottom of the flume and were always in contact with the water surface. The range data measured in the experiments was subtracted from the measured distance to the flume bottom to result in bed elevations. The working section of the flume, which took 3.85 minutes to scan, extended from 7.7 meters to 22.7 meters from the origin at the flume headbox. Position data recorded along with the acoustic range data was used to assign streamwise positions relative to the flume origin.Why the dataset was generated: Relative to the research into sediment transport in unsteady flows for gravel and gravel/sand mixtures, less research has focused on sand-bedded channels and the evolution of sand bedforms in response to changing flows. Even less research has combined sand load with detailed topographic measurements to arrive at a comprehensive picture of the adjustment processes for topography and transport rate caused by unsteady flow conditions. Additional research is needed to provide the data necessary for investigating relationships between unsteady flow rates, sediment transport, and bed topography. The dataset expands on previous research into sediment transport and bed topography in unsteady flows by having detailed, real-time measurements of bed topography over the width of a 15-m section of a laboratory flume, continuous measurements of sediment transport rate throughout the experiments, and continuous measurements of water-surface slope at 10 points along the test section. These measurements allowed for interactions between changing flow rates, bed topography, water surface slope, and sediment transport to be evaluated before, during, and after the flow hydrographs. The results include detailed analysis of data collected during non-symmetric flow hydrographs of 1-, 2-, 3-, 4-, 5-, and 6-hour duration over a sand bed in a laboratory flume at the USDA-ARS National Sedimentation Laboratory.Data resources: Each file contains the data used to generate the figure corresponding to the figure number in the filename for the publication (to be updated with accepted and published): Wren, D. G., Kuhnle, R. A., McAlpin, T. O., Langendoen, E. L. Sediment transport and bed topography for realistic unsteady flow hydrographs of varying length in a laboratory flume. Journal of Hydraulic Engineering. DOI:10.1061/JHEND8/HYENG-13769.CSV variable output from Figure_1.csv CSV variable output from Figure_2.csv CSV variable output from Figure_3.csv CSV variable output from Figure_4.csv CSV variable output from Figure_5.csv CSV variable output from Figure_6.csv CSV variable output from Figure_7.csv CSV variable output from Figure_8.csv CSV variable output from Figure_9.csv CSV variable output from Figure_10.csv CSV variable output from Figure_11.csv CSV variable output from Figure_12.csv CSV variable output from Figure_13.csv CSV variable output from Figure_14.csv

本数据集系用于制作《实验室明渠中不同长度不规则流动水力过程的沉积物输运及床面地形》一文中图表的依据。该文献引用信息如下：Wren, D. G., Kuhnle, R. A., McAlpin, T. O., Langendoen, E. L. 沉积物输运及床面地形：实验室明渠中不同长度不规则流动水力过程的真实模拟。水利工程技术学报，10.1061/JHEND8/HYENG-13769。数据集的生成过程如下：于美国农业部ARS国家沉积物实验室，于一个长30米、宽1.22米、深0.61米的明渠中，利用频率可控的泵电机和可调坡度进行实验。底床所用砂石源自当地，中值粒径为0.43毫米。通过Sedflux系统测量床载输运率，该系统以1赫兹（赫兹，每秒周期数）的频率运行，使用两个悬挂于由负载细胞支撑的、宽1.2米、长0.57米的沉积物收集器上，距离渠道起点的距离为28.5米。收集器中累积的沙石质量被连续记录，当沙石质量达到30千克时，将收集器倾倒。沙粒在离开收集器后，通过直径为0.152米的管道循环，并在上游端重新进入明渠。绕过收集器的材料进入主回水管，并在泵叶轮下游的回水管中心位置，使用直径为10.6毫米的采样喷嘴进行采样。采样喷嘴内的流速与平均回水管流速相匹配，以避免对浓度测量的偏差。通过测量随时间累积的水的质量来检查采样线中的排放量。将含有沙石的浑水通过直径为0.062毫米的筛网，筛网保留沙粒，允许水返回明渠。使用物理样品计算的平均沉积物浓度，用于计算绕过Sedflux系统的负荷。床面高程通过声学方法以10赫兹的频率进行测量，使用频率为每秒500万周期的32个传感器依次发射。传感器以3.7厘米的间隔安装在钝面和窄尾缘的PVC杆上，以最小化流动分离和阻力。传感器与明渠底部保持恒定距离，并始终与水面接触。实验中测量的范围数据从测量距离减去明渠底部距离，得到床面高程。明渠的工作部分，从明渠头部箱起7.7米至22.7米，耗时3.85分钟进行扫描。与声学范围数据一同记录的位置数据被用于确定相对于明渠起点的流向位置。数据集生成的原因：相较于对砾石和砾石/沙混合物在非稳定流动中的沉积物输运研究，对沙床渠道及沙床地形形态随流量变化而演化的研究相对较少。将沙载与详细的地质测量相结合，以全面了解由非稳定流动条件引起的地形和输运率调整过程的研究更为罕见。因此，有必要进行额外研究，以提供调查非稳定流速、沉积物输运和床面地形之间关系所需的数据。该数据集在之前关于非稳定流动中的沉积物输运和床面地形研究的基础上，通过在实验室明渠15米宽的横截面上进行详细的床面地形实时测量、实验过程中沉积物输运率的连续测量，以及在测试段10个位置处连续测量水面坡度，从而评估了在流量水力过程之前、期间和之后的流量速率、床面地形、水面坡度和沉积物输运之间的相互作用。结果包括对在USDA-ARS国家沉积物实验室的明渠中，对1小时、2小时、3小时、4小时、5小时和6小时非对称流量水力过程进行详细分析的数据收集。数据资源：每个文件包含用于生成与文件名中图号相对应的图的所需数据（将根据已接受和发表的内容进行更新）：Wren, D. G., Kuhnle, R. A., McAlpin, T. O., Langendoen, E. L. 沉积物输运及床面地形：实验室明渠中不同长度不规则流动水力过程的真实模拟。水利工程技术学报。DOI：10.1061/JHEND8/HYENG-13769。CSV变量输出：Figure_1.csv，Figure_2.csv，Figure_3.csv，Figure_4.csv，Figure_5.csv，Figure_6.csv，Figure_7.csv，Figure_8.csv，Figure_9.csv，Figure_10.csv，Figure_11.csv，Figure_12.csv，Figure_13.csv，Figure_14.csv。