It is difficult to explain the reason of higher regulation water level determined by the method of the second bed-forming discharge because of the lack of understanding on the theoretical basis,basic concept and applicability of the method.

The first bed-forming discharge represents equivalent discharge of sediment transporting capacity in variable discharge process,i.

The paper studies the method of determining parameter m of bed-building discharge,analyses the influence of m determined by different methods to bed-building discharge,the result indicates that the parameter m determined by the bed-building discharge method has a large influence to the bed-building discharge in the studied river stream,the parameter m has to be determined with great care.

Analysis of dominant discharge on the middle and lower reaches of the Songhua River;

On the basis of analyaing and summarizing the achievements of predecessors about the dominant discharge, considering the characters of heaVy sediment laden river, this paper presents a method to determine the dominant discharge of heaVy sediment-laden river, in which the frequencies of discharge and sediment concentration are used.

To calculate transverse and longitudinal profile morphology under the conditions of reaching the bal ance of design conditions of water and sediment by using the first and second bed forming discharge, analysis and compare with the morphological feature of the Sanmenxia Reservoir, it has obtained that the design for mation and effective storage of the Xiaolangdi Reservoir are Conservative.