Dataset associated to Ji et al. Field-scale Analysis of Flow Dynamics and Turbulent Structures in a Compound Channel with Emergent Rigid Floodplain Vegetation

These data are the results of experimental flume runs conducted at the Korea Institute of Civil Engineering and Building Technology – River Experiment Center in Andong, South Korea. The experiments were designed to investigate flow dynamics and turbulence characteristics in the presence of emergent rigid vegetation located on the floodplain of a compound channel. The dataset consists of one Excel file with multiple sheets reporting hydraulic conditions, cross-sectional geometry, and drag coefficient estimation, and one folder containing the velocity data at Sections A and B. The velocity dataset includes filtered ADV velocity time series stored in .dat files and Excel files containing the processed data used to characterize the mean flow field, turbulence statistics, and coherent flow structures. Discharge was measured upstream of the experimental reach using an acoustic Doppler current profiler (ADCP). Multiple discharge measurements were repeated during the experiment to verify stable flow conditions. Water levels were measured using pressure sensors installed at cross-sections C1, C2, C3, and C4. Water levels at Sections A and B were estimated by linear interpolation based on the measured values at the adjacent sections. The sensors have an accuracy of ±0.05%. Water levels were recorded at 10 s intervals during the experiment and were used to estimate the water surface slope, friction slope, and friction factors within the experimental section. Cross-sectional geometry was surveyed at Sections A and B using a Total Station. Geometry data for Sections C1, C2, C3, and C4 were estimated by linear interpolation between Sections A and B while considering the longitudinal bed slope of the channel. The surveyed geometry was used to compute hydraulic parameters including cross-sectional flow area, wetted perimeter, and hydraulic radius. The dataset also includes a spreadsheet used for estimating the vegetation drag coefficient CD under the experimental flow conditions. The calculations are based on previously proposed models and include the input hydraulic parameters, intermediate variables, and resulting CD values obtained from the models of Schlichting and Gersten (1982), Ishikawa et al. (2000), Tanino and Nepf (2008), Kothyari et al. (2009), Cheng and Nguyen (2011), Cheng (2013), Liu and Zeng (2017), and D'Ippolito et al. (2019). Velocity measurements were carried out at two cross-sections, referred to as Section A and Section B. Section A represents the non-vegetated cross section and was located 20 m upstream of the vegetated floodplain. Section B was located 40 m downstream of the vegetation edge and includes model rigid vegetation installed on the floodplain. At each cross-section, three-dimensional instantaneous velocity was measured at 84 spatial locations with a sampling frequency of 25 Hz. The duration of the velocity recordings ranges between 600 s and 900 s depending on the measurement point location. These data support the analysis presented in the associated research article. A detailed description of the experimental setup, hydraulic conditions, measurement procedures, and data processing methods is provided in the following article: Ji et al., Field-scale Analysis of Flow Dynamics and Turbulent Structures in a Compound Channel with Emergent Rigid Floodplain Vegetation, submitted to the Journal of Hydraulic Engineering. This dataset is intended to support reproducibility of the experimental results and may be used for further investigations on flow-vegetation interactions, turbulence structure in compound channels and validation of numerical or theoretical models.