Tracing experiment in the Inner Mongolia reach of the Upper Yellow River in May 2017

A large scale tracing experiment had been conducted from May 26 to 31, 2017 by us to determine the times of travel in the upper Yellow River, Baotou, Inner Mongolia, China. For the discharge of 233 m³/s, 48.75 kg powder of acid red 52 was divided into 39 equal parts. Each part was put into a bucket respectively. Added the tap water into the 39 buckets and stirred well to fully dissolve the powder at factory. The dye solution was poured into Yellow River simultaneously and instantaneously, facing downstream, in only about the central 75 percent of the flow, at 06:50 on 26 May 2017 at 39 points from the Wangdahan floating bridge. Each pouring point was located at the approximate center of flow of each 39 equal discharge segments according to hydrometric specialist's experience. Considering the work safety, water samples were collected at banks (0.5 m to 1.5 m from water's edge) and at center flow on floating bridges. A series of water samples at 8 cross-sections of Wangdahan floating bridge, Tianjiayingzi, Dengkou, Dachengxi road bridge, Wujuniu floating bridge, Erdaohao floating bridge, Wuergeliang floating bridge and Madihao pumping station were collected and sealed into a glass bottle of 100 ml once at some given intervals such as 5 min, 10 min, 15 min, 20 min 25 min and 30 min. The water samples were sent to a laboratory for a static settlement in a water tank at least for 16 hrs. Dye concentration was measured in situ and in a laboratory by a Turner Designs Fluorometer 10-005. The fluorometer were calibrated by a prepared standard regent of 170 ppb by using deionized water to dissolve the powder of acid red 52. The concentration in the clear supernatant liquid after settlement was measured in a laboratory. After supernatant liquid temperature correction, the measured concentration was transformed to determined concentration. The average concentration in the water samples collected at Wangdahan floating bridge before dye pour was taken as background value for sampling sites of Tianjiayingzi and Dengkou. At the other seven sampling sites of Dachengxi road bridge, Wujuniu floating bridge, Erdaohao floating bridge, Wuergeliang floating bridge and Madihao pumping station, the initial consecutive minimum average concentration was taken as its background value. The observed concentration was formed by subtracting the background value from the determined one. This data set includes all the observed time concentration data at seven sampling sites in the 170 km long study reach. For the seven sampling sites, the time concentration data points were fitted by using the three-parameter log-normal probability density equation. The fitted parameters and curves are included in this data set. The potential usage of this data set includes three aspects. Firstly, estimate the peak concentration and travel times of peak concentration, leading edge and traling edge for an instantaneous source. Secondly, the mean velocity derived from the centroid of the fitted curve can be taken as mean flow velocity which is used to calculate the self-purification capacity of a reach. Thirdly, the data can be used to calibrate a hydraulic model and a water quality model.