Evaluation of ADCP Apparent Bed Load Velocity in a Large Sand-Bed River: Moving versus Stationary Boat Conditions

作者：Jamieson E C^*; Rennie C D; Jacobson R B; Townsend R D

来源：Journal of Hydraulic Engineering, 2011, 137(9): 1064-1071.

DOI：10.1061/(ASCE)HY.1943-7900.0000373

• Bed load transport
• ADCP
• Bed velocity bias
• Field measurements
• Missouri River

Detailed mapping of bathymetry and apparent bed load velocity using a boat-mounted acoustic Doppler current profiler (ADCP) was carried out along a 388-m section of the lower Missouri River near Columbia, Missouri. Sampling transects (moving boat) were completed at 5- and 20-m spacing along the study section. Stationary (fixed-boat) measurements were made by maintaining constant boat position over a target point where the position of the boat did not deviate more than 3 m in any direction. For each transect and stationary measurement, apparent bed load velocity (nu(b)) was estimated using ADCP bottom tracking data and high precision real-time kinematic (RTK) global positioning system (GPS). The principal objectives of this research are to (1) determine whether boat motion introduces a bias in apparent bed load velocity measurements; and (2) evaluate the reliability of ADCP bed velocity measurements for a range of sediment transport environments. Results indicate that both high transport ((nu) over bar (b)> 0.6 m/s) and moving-boat conditions (for both high and low transport environments) increase the relative variability in estimates of mean bed velocity. Despite this, the spatially dense single-transect measurements were capable of producing detailed bed velocity maps that correspond closely with the expected pattern of sediment transport over large dunes. DOI: 10.1061/(ASCE)HY.1943-7900.0000373.

• 出版日期2011-9