The conditions for tidal bore formation and its effect on the transport of saline water at river mouths

Abstract

Approaches to the mathematical description of bore propagation upstream a river in its mouth area are briefly reviewed. Data on some river mouths, where bores were observed, are given, and the conditions of their formation are considered. The existence of a bore is determined by tide magnitude, river runoff, and the depth profile in the estuary. The same factors govern seawater penetration distance into river mouths, the degree of mixing of seawater and river water, and the regularities of sediment motion at river mouths. The types of water circulation at the mouths of the greatest rivers, where bore takes place, are considered, and its effect on seawater intrusion range into river mouths is analyzed. The results of comparison of the effect of channel training on bore existence conditions and the propagation range of saline water into the estuaries of the Seine (France) and Qiantang (China) are given.