A Study On The Fluvial Process Of The Lower Yellow River In The Last 30 Years

In recent years, human activities affect the bounder conditions of thelower Yellow River greatly, the discharge & load of the river decreasedsharply from 1986. Under these new conditions, new fluvial trends haveshown on the plain morphology,longitudinal section and cross section in thelower Yellow River. At the same time, how to control the fluvial process ofthe Yellow River after the running of the Xiaolangdi reservoir is also a seriousproblem in front of us. Thus, it is necessary to study the relationship betweenthe fluvial process and the discharge & load condition under different bounderconditions.This paper studies the features of discharge & load from 1960 to 1997;thethe plain morphology,longitudinal section and cross section feature of the riverfrom 1977 to 2002;the relationships between the morphologicalcharacteristics and water & sediment load in the lower Yellow River byemploying statistic and correlation analysis.The main conclusion of the paper is: 1,the relationship between meanderfeatures and average discharge of 0 to 5 years is positive correlation, and therelationship between meander features and average load of 0 to 4 years is negativecorrelation. 2,meander development is behind the change of diacharge & load. Thetime meanders need to adapt new water load is 2-3 years;the most efficientproportion of water load for evolution of meanders has also been researched oncondition that river inertia is three years. 3,the decrease of impulse intensity ofdischarge is useful to the stability of the river. 4,the longitudinal section of the lowerYellow River is S.The new standpoints of the paper are as follows: 1,the time meandersdevelopment behind the discharge is about three years. 2,characteristic numbers ofmeanders have good correlation relationship to the year distribution of the discharge& load. 3,the trend of the longitudinal section of the Yellow River is S.These results may be useful for management and regulation of the lower YellowRiver, analyzing the development of the meanders, the feature of longitudinal andtansversal profile under new water & sediment load, forcasting the time needed forthe best correlation relationship between the geometric characteristics of meandersand the variation of water and load, revising the operation scheme of the Xiaolangdireservoir considering the fluvial process in the downstream reaches.