Acoustic Doppler current profiler measurements in the Yellow River Delta

The Yellow River Delta (YRD) in China is a highly active morphodynamic environment subjected to both climatic driven naturally variations and anthropogenic stresses and other modes of transitions. The (DELIGHT) research project is aiming at developing an integrated management system for the Yellow River delta region. In October 2013, a field campaign was undertaken in the Yellow River Delta conducting vessel-based in-situ measurements of: water depth profiles and bottom sediment composition utilizing a parametric sub-bottom profiler, 3D-current velocities by Acoustic-Doppler-Current-Profiler (ADCP), conductivity, temperature, depth, oxygen saturation, pH and turbidity by CTD-probe, fluid densities by supersonic density probe and point velocities by electromagnetic current meter.

Supplementary water and sediment samples have been collected. Measurements presented are processed for further usage as calibration data for a three dimensional hydro-morphodynamic numerical model covering the YRD and the adjacent Bohai Sea. Another field campaign is currently being planned for mid-2015 in order to obtain validation data.

Figure 2 shows an exemplary exemplary ADCP-transect with depth averaged current velocities, position and tidal gauge (Figure 1) information. Current velocities reach magnitudes up to 0.5 m/s within the main stream and up to 0.2 m/s in the shallow regions. The transect was measured at the pontoon bridge (RKM 0).

Fig.1: Time history of measured water level (a) with marked ADCP-measurement time; ADCP-transect position within YRD (b).

The Yellow River exhibits a rather regular parabolic profile at this position (see Figure 5 (a), which leads to a regular current velocity field across (see Figure 2 (b)).

Fig.2: ADCP-transect displaying current velocities as magnitude (a) ranging up to 0.5 m/s; Orientation of the transect within the YR and depth averaged current velocities (b).