Comments on the Main Yellow River Channel

The paper analyzes the meanings of river channel,main channel and floodplain and their interrelationships by taking the lower Yellow River where the channel evolution is the most severe as an example.The cross-section of alluvial channel is compound one,usually can be divided into several parts of low water channel,class one,class two and class three floodplains.The main channel is the riverbed part where for passing one event of a major flood,including low water channel and newly formed floodplain where is the main passageway for water and sediment.The river channel covers the parts of the area of main channel variation in a long period of time,the main channel,secondary floodplain or parts of secondary floodplain where are the river bed part for passing through greater floods with faster velocity during flood season.The newly formed floodplain is the part of main channel.The river channel and floodplain can be mutually changed.