Patterns of seawater intrusion at a river mouth

Zhenren Guo, Shibin Qi, Daojian Huang

Thursday 2 july 2015

12:15 - 12:30h at Europe 1 & 2 (level 0)

Themes: (T) Managing deltas, (ST) Saline and freshwater interaction

Parallel session: 11K. Managing deltas - Saline

Based on data from field survey and numerical modeling, seawater intrusion patterns and salinity process in Modaomen Waterway of the Pearl River Estuary are studied. It is found that seawater intrudes and exists in this waterway alternately in three patterns, i.e., saline wedge – transition – fully mixing – transition – saline wedge, under certain combinations of hydrodynamic conditions of the river and the sea. This alternate change of seawater intrusion makes the salinity process on river cross section periodically changing with the lunar cycle of tide. In view of this, an indicator and a set of criteria are developed to predict patterns of seawater intrusion using mainly freshwater discharge from upstream of the river and tidal range. This prediction forms a base to further predict salinity process at any point in the river course so as to serve for water intake and irrigation.