Typical Shiyang River Basin Characteristic Stage Demonstrated And Water Level For Flood Control

During the real-time operation of reservoirs, the limit water level is such an important and sensitive index that it directly affects how to reasonably mitigate the contradiction between flood control and benefits of reservoirs. And it is very urgent to describe flood seasons of reservoirs, to reasonably define the limit water level, to find an operable real-time control method of the limit level and to establish an appropriate control model of the limit level.For reservoirs, water storage&flood control are a pair of paradox. If the limited water levels for flood control during flood season are set to be high, it is advantageous for water storage and disadvantageous for flood control and vise versa. In order to resolve this paradox, three concepts and their determining methods of stage storm, stage design flood and stage the limited water levels for flood control are discussed in this paper. First, divide the flood season into different stages according to hydrology statistic theory, determine stage design storm by the method of frequency lining or stochastic series extending. Second, under the two presume one ia that stage design storm and stage design flood have same frequency, the other is that the largest stage design strom is the counterpart of year design flood, determine stage design flood from stage design strom in the light of same ratio scaling. Third, under the type of grading fixed discharge for reservoir dispatch, determine stage the limited water levels for flood control from stage design flood. The above concepts and determining methods are illustrated in detail by using Huangyang reservoir as an example.At present, the study on stage design storm, stage design flood, stage the limited water levels for flood control and dynamic stage the limited water levels for flood control is just beginning and there is no successful theoty to refer to. For stage design storm, two determining methods frequency lining and stochastic time-series extending are presented in this paper. For stage design flood, under the two presumes mentioned above, same ratio scaling is chosen here to determine stage design flood from stage design storm. For stage the limited water levels for flood control, it is determined by the conventional reservoir dispatch method.