Based on the characteristics of climate and hydrological process in the Yangtze River during the flood season in 2006, and considering the impatcs of major projects on the runoff in the middle and lower reaches of the Yangtze River, Professor Chen Xiqing，chief professor of Hydro-Lab , on September 4, made long-term forecast on the trend of discharges of the Yangtze River into the sea from autumn 2006 to spring 2007, suggesting the high possibility and long duration of salt intrusion during this period. Prof. Chen submitted this report to the Shanghai municipal government to suggest them pay more attention to the saltwater Intrusion in the Yangtze estuary, which may cause the socio-economic impacts from the view of urban water security, and suggest them be under a state of alert and make countermeasures to this problem.

  In the middle August of 2006, Professor Chen Xiqing called Mr. Gu Yuliang, the chief engineer of Shanghai-Yuanshui stock company limited, to talk bout this issue, and submitted special report "Yangtze River Mouth saline intrusion, formulate plans to deal with urban water supply". This report addressed the long-term change trend of the Yangtze River flows into the sea from five aspects, which has attracted great attention from leaders in Shanghai Water Affairs Authority. Zhang Jiayi, director of Shanghai Water Affairs Authority, replied to Prof. Chen and highly praised and thanked for what he has contributed. Mr.Zhang also said that they will conduct special studies and research on this issue, and take effective measures to ensure the water supply of industry, agriculture and urban people's living needs in Shanghai (see Chief Zhang’s letter of thanks).

  On September11, just one week later after the submission of the proposals, the saltwater-Intrusion appeared for the first time. Saltwater lasted for six days and the chloride concentration which is over 250 milligrams per liter continued more than 108 hours. On October 9, saltwater-Intrusion happened again, which was twice the duration of regular time and the maximum chloride concentrations was up to 1,400. On October 24, saltwater Intrusion came to Yangtze River Estuary for the third time, which has affected the water intake in Chenhang Reservoir. Fished died in a large area in Pudong inner river due to the saltwater intrusion, but thanks to the timely countermeasure carried out by Shanghai, the water supply has not yet been affected by saltwater.