Analysis of river bed change of Yangtze River and flood level variation

Based on a large number of field data, the flood level and bed level variation at the middle and lower reaches of the Yangtze River in the last 50 years, has been analyzed. It has been found that there is nearly relationship between the river and lake beds variation and the phenomenon of flood level going up distinctly and keeping long time. And the theoretical relationship has been analyzed in detail so as to offer an important basis to analyze influential factors on higher flood level.