Characterizing ship-induced hydrodynamics in a heavy shipping traffic waterway via intensified field measurements

Abstract

Ship-induced hydrodynamics play an important role in shaping the cross-sectional profile of inland waterways and produce a large amount of pressure on the fluvial environment. This study aimed at quantifying the characteristics of ship-induced waves and currents in a heavy shipping traffic waterway via intensified field measurements conducted in the Changzhou segment of the Grand Canal, in Jiangsu Province, China. Based on the processed hydrodynamic data, waves and currents caused by single ships and multiple ships were investigated. For single ships, the ship-induced wave heights estimated with empirical formulas were not consistent with the observations. Categorized by the loading conditions of barges, the drawdown height was characterized by the ratio of ship speed to its limit speed. The maximum non-dimensional ship-induced wave height was parameterized by a nonlinear combination of the depth Froude number and a blockage coefficient. For multiple ships, when ships closely followed each other or interlaced each other's paths, it was difficult to characterize the superposition of several ship wakes. The magnitudes of current velocities induced by single ships and multiple ships were respectively nine and six times as large as those of natural flow. This may result in more severe sediment (re)suspension than natural flows.

Keywords

• Ship-induced waves
• Drawdown
• Field measurements
• Current velocity
• Sediment (re)suspension
• Grand Canal