Abstract: This paper proposes a probabilitic constrained programming mcdel for the optimal design of flood control reservoir. The model explicitly considers a set of probability constaints on the occurrences of reservoir flood and local flood. The iiexible tolerance algorithm is applied to solve the proposed model. An example shows its successful application.
Abstract: The weighted function moments method is one of the principal methods to estimate the parameters of P-Ⅲ distribution in China, but it can only be applied in simple hydrological series. The formulae of parameters with historical flood series of above method have been derived in the paper. Based upon the Monte-Carlo experiments the results of the unbiasness and efficiency of the parameters and design flood values show that above formulae are effective, so the applied scope of weighted function moments method is expanded in the paper.
Abstract: Through the analysis of the operational plan used in the Yuecheng Reservoir, a new operational plan which is the operational way through the control of flood peak and flood volume is proposed. This paper proves that the new operational plan holds good operable and is safe for the reservoir itself and the downstream on the flood control. Adopting the new operational plan, the flood level will lower about 1.1m than what the old way does,when the flood recurrence interval is 1000 years:the normal flood control standard of the reservoir will be improved and the flood recurrence interval will be improved from 1000 years to 1600 years;and the flood recurrence interval of the unusual standard will be raised from 2000 years to 2600 years. If the flood control stanlard does not be improved, the new plan will make the limiting level during flood season from 131m to 135m.
Abstract: In this paper, a simple infiltration model is proposed on the basis of a theoretical consideration of infiltration and the displacement of existing soil water by newly-infiltrating rainiail. A method for estimating the mean suction of the wetting front is given,and is applied to determine rainfall excess and to predict total runoff.Comparison of the predicted and the measured data shows excellent agreement.
Abstract: Based on the hourly rainfall data set from the hydrological rainfall observational network, the features of the rain storm activity over the Tai Lake Basin and the Lixiahe Area during two periods of sustained torrential rain in June-July 1991 are analyzed. The results show that there are frequent rain storm activities over the two areas and the regimes of the rain storm activity are different between the two areas. The rain storms move mainly eastwards with stationary sometimes. The rainfall of rain ctorm is a great part of the precipitation for the period of sustained torrential rain and takes an important role in the formation and development of the torrential rain flood and waterlogging. The rain storm activities relate to the mesosynoptic sxstems such as the mesoscale shear line, the mesoscale convergence line and the mesoscale convergence center.
Abstract: This paper expounds the systematic errors existing in operation various flow routing models and the resasons causing the errors. The Retarding Discharge Routing Model and its corresponding flow routing method are advanced on the basis of the relation between channel strorage and discharge. The fact that this model is superior to Muskingum Routing Model taking non-linear effect into account has been proved by a given example.
Abstract: A two-dimensional mathematical model of velocity field in a dredged channel at oblique angle to flow directin in open water is established in this paper. The calculated results are consistent with the experiment results by Yuan Meiqi, Li Anzhong etc.The velocity fields of natural condition (e. g. every kind of depth depth ratio, and angle between a degreded channel and flow direction) are calculated by this model.The figure of the coefficient of velocity ratio versus oblique angale with depth ratio (fig. 4) and the figure of flow direction in the middle of the gredged channel with dredged channel versus oblique angle with depth ratio (fig. 5) are obtained. Therefore, a basis is provided for selecting a proper direction for a dredged channel.
Abstract: Based on the flow pattern effected by submerged dikes, the flow is divided into regions near dike. Formulas used to determine the local head losses of single submerged dike and the mean velocity of main channel varying with distance downstream are derived. And using the above formulas, the head losses of non-isolength submerged dikes are obtained. The results of the computation show good agreement with the measured values in the flume.
Abstract: Some problems relative to hydraulic calculation of serial submerged spur dikes have been studied on the fixed bed physical model of Sanxing Bank, and a calculation method of supposed roughness for water level of serial submerged spur dikes is presented in the paper, which is very simple and useful, and in good agreement with measured data.
Abstract: On the basis of analing and summarizing the achievements of predecessors about the dominant discharge, considering the characters of heavy sedimentladen 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. The resuets of application to the Yellow River and the Yongding Rivers show that this method is available.
Abstract: Cavitation characteristics of filling values on Gezhouba No. 1 Lock prototype is studied. Spectrum analysis technique is used in this paper for the noise data recorded, and much information is drawn including intial and critical state of cavitation, types of cavitation involved, intensity of cavitation, etc. The related phenomena of cavitation and the nature of bottom edge cavitation and top gap cavitation are described. The paper points out that there existed gap cavitation near bottom edge at the beginning of value opening, which was never mentioned before in literatures. In additions, the effect of cavitation on pressure and hoisting load is discoursed. The relation-ship between low frequency noises and vibration of hoisting rods is presented at length in this paper.
Abstract: The paper introduces briefly the basic principles of Bayesian analysis, reviews its applications to uncertainty analysis and decision making in runoff forecasts, flood analysis and regionalization, water resources planning and management, etc., presents the recommendations for further researches, and provides emphatically the authors' combination approach that integrates grey prior distribution and fuzzy likelihood function into a Bayesian framework.
Abstract: This paper introduces briefly three hydrologic models commonly used in China, discusses the mechanisms of evaporation, infiltration, and yield as well as concentration of runoff in these models, and investigates into some problems encountered in aplications.