CHANNEL SHIFTING OF LOWER YELLOW RIVER IN 1128-1855AD AND ITS INFLUENCE TO THE SEDIMENTATION IN BOHAI, YELLOW AND EAST CHINA SEAS

The crevassing,flooding and channel shifting of the lower reach of Yellow River in 1128—1855 are of great importance to marine sedimentation and coastal geomorphology in Bohai,Yellow and East China Seas.However,there are four views on the historical events among Chinese scholars.In fact,during the year of 1128—1494,the Yellow River water never entered the Bohai Sea totally,never entered the Yellow Sea and Bohai Sea alternatively,never entered the Bohai Sea and Yellow Sea simultaneously.There was only flood water entered the Bohai Sea in a few years during the period.1128 is of great importance rather than 1194 for sedimentation in eastern China Seas.The history of the lower Yellow River channel in 1128—1855 can be divided into three stages:(1) The Yellow River entered the Yellow Sea through the original Huaihe River channel and only part of Yellow River water entered the Bohai Sea occasionally in 1128—1494.Therefore,little sediments were brought into the Bohai Sea.(2) From 1494 up to 1579,The Yellow River water was totally poured into the Yellow Sea through several channels.The sediments into the Yellow Sea increased.(3) In 1579—1855,the Yellow River was restricted into a single stable lower channel by man-made dykes.The sediments into Yellow Sea further increased.The Yellow River Delta superlobes on the northern Shandong Peninsula had been abandoned during the period of 1128—1494.From 1494 up to 1855,the sediments coming from the Yellow River had further moved south and deposited in the Yellow Sea and East China Sea.