The Study Of The Influence Of Narrowing The River On Flood Water Level In The Lower Yellow River

It is universal phenomena the the river bed is scoured while discharge rising and depositing while discharge dropping in a flood period. It is pointed that the phenomena is not in a position to explain with formula of sediment-holding flow, so the bed scouring is incapable to calculate by theory formula. The Math model based on the formula of sediment-holding flow is also incapable the relation between water discharge and water level. To analyzing the observed data is one of reliable, important and convictive way. In this paper, we analysed and calculating the various channel width relation between flow discharge and water lever by the means of analyzing observed data of flow measuring station including Huayuankou, Jiahetan, Gaocun and Sunkou etc, and writing computer program complying with the criterion. Result show that,at the same flow variety, the water level rising ratio on the Henan reache in the lower is lower than on the Shandong reache in the lower Yellow River.The was explained that the reason why the flow rising ratio was lower is that channel bed was scoured while flow rising in period flood on sand river. The Reason of flow rising ratio deference between two reaches is gradient at Henan reach is steeper than Shandong reach. While the scouring intensity between two reaches is not distinct. Influence of double bank on Manning n is very poor. The correctness was demonstrate by comparing other literature.The factors of Influence on relation between flow discharge and water level is various, analyzing above context. After analysing the characteristic flow vary in period flood, we reckon that , on wander river(above Sunkou), flow condition is changing at all time, it result in the randomicity of scouring and depositing in less water discharge rising period, and Discharge Coefficient complexity etc. To sum up: the calculating result is conservativer.