Effects of Qiandao Lake water diversion project on Qiantang River estuary saltwater intrusion

Qiandao Lake water diversion project will change the runoff process of the Fuchun reservoir and the salinity of Qiantang River estuary. A two-dimensional numerical salinity model which including tidal bore's action is established. Based on tide and salinity testing, the distance of saltwater intrusion and the exceeding period of important water inlets caused by the project are calculated. Results showed that, it will be significantly effected in the low flow year by the current scheduling scheme, the distance of saltwater intrusion is increased 3 700 meters and time available for water inlets time along the river is shorten 0.2~3.6 days, but it is little effected in normal and high flow year. In order to reduce the influence of the salt water intrusion which happened due to the project in low flow year, a reservoir optimal operation is necessary.