Investigating cost-effective single-beam survey configurations for accurate river bathymetry construction

Abstract

River bathymetry is needed to accurately simulate river hydrodynamics. River bathymetric data are typically collected through boat-mounted single- or multi-beam echosounder surveys. Detailed bathymetric data from multibeam surveys may exceed the requirements of standard river hydraulic models (1D and 2D). Compared to data-intensive but expensive multibeam surveys, single-beam surveys are cost-effective. Single-beam surveys can sufficiently inform river simulations when coupled with specific preprocessing and interpolation techniques. This study contrasts two survey patterns, including the commonly used but under-studied zigzag surveys, against the traditional cross-sectional surveys. Linear and anisotropic Kriging interpolations, two widely used methods, are applied to construct bathymetry mesh from different survey configurations. Results from this study highlight efficient survey configurations for both cross-sectional and zigzag patterns, balancing accuracy and cost. Notably, zigzag surveys approach the efficacy of cross-sectional surveys when spaced below a certain threshold, but Kriging interpolation shows diminished performance with sparse zigzag surveys. The findings from this study bridge gaps in previous research by offering nuanced comparisons between survey configurations and interpolations. This study offers a comparative analysis to guide more effective planning and utilization of single-beam surveys, without advocating for specific survey patterns or interpolation techniques.