Experimental study on effects of flood peak discharge on formation of cross-section in the lower Yellow River;

Effection factors on the accuracy of flood peak discharge using gradiet method;

Based on Min Qian power function formula of flood grade, one method for classifying flood grades by standardized value of flood peak discharge or flood peak stage is put forward in this paper.

2 m of Tongguan elevation in peach flood season under the present boundary condition of the channel are as follows: peak discharge of Tongguan Station 2 500 m3/s,flood volume of 10 d 1.

At the same time,the design flood peak discharge and hydrograph are calculated by analyzing the flood of YanQu gauging station and the frequency of the flood.

The obtained new formula of peak discharge envelope curve of known maximum flood in the world according to a vast amount of f.

By the comparative analysis of mean flood process and characteristic volume before and after harness ,it shows that though the mean process rainfall after harness is bigger than that before harness, the peak flood and flood volume tend to decrease, and the sediment amount is decreased at 20 percent, and the flood rises and falls slowly.

At present, the design peak flow in urban channels is generally calculated with the rational formula from water conservancy authority and the formula for stormwater flow calculation from municipal authority, but the runoff and afflux characteristics and design standards in the urban area do not fit the conditions assumed for either of the formulae.

A bivariate extremal distribution is adopted to analyze the joint distribution between the annual flood peak Q and flood volume V observed at a hydrological station of the Yangtze River.

An exponential function was proposed for calculation of flood peak on the basic theory that the relation beween water level and flow rate is relatively stable at a regular river section.

Through analysis precision measured discharge data,the reliability of rush measurement of flood peak by velocimeter with one point method on water sucface was analysed.