Study On Flood Forecasting And Forecasted Flood Operation Rule For Yingnahe Reservoir

Flood brings human enormous life and property damage. Currently there are two ways to deal with flood disasters:engineering measures and non-engineering measures. Reservoir, as the most important engineering measures, has played a tremendous role in flood control and disaster reduction; on the other hand, the practice has proved that scientific and reasonable flood dispatching as the non-structural measures is the key to make the safe operation of the reservoir, reduce flood loss and realize the maximization of flood resource utilization. In real-time flood dispatching, flood forecasting can not only extend the expected flood forecast period, but also clear the flood information, which helps dispatchers with scientific decision-making. While in the implementation of reservoir flood control operation based on forecasting, especially for reservoir with small flood control capacity, the issue of flood forecasting errors is considered.Based on the above discussion, this paper takes Yingnahe reservoir as the example, and chooses the suitable forecast model for establishing flood forecasting scheme through analysis of flood characteristics according to the existing reservoir hydrological data; Considering the runoff forecast error, Yingnahe reservoir flood control forecast operation is preliminarily set and the rationality of reservoir dispatching rules is analyzed.The main research contents and results are as follows:(1) Yingnahe reservoir has short years of hydrological data, poor precision of observation equipment may lead to reducing authenticity of the data, and therefore data reliability, consistency and representative are reviewed, which focus on analysis of water balance. In addition, correction or extrapolation of data interpolation are made on hydrological data with problems existing.(2) This paper chooses twenty one floods that have reasonable rainfall flood relationship. After analysis of underlying surface conditions, climate conditions and other aspects of Yingnahe basin characteristics, Xinanjiang flood forecasting model is selected. In the process of establishing the scheme, unclassified forecasting is the first consideration. If unclassified forecasting scheme cannot meet the forecasting precision and practical application requirements, the flood classification is needed. In the process of twenty one unclassified runoff simulations, nineteen floods are qualified. The runoff forecasting qualified rate reaches 90 percent, and its precision grade is first-grade. But the unclassified concentration simulation has the low precision. Therefore, seventeen floods are classified according to initial soil moisture of every flood. Only three floods are unqualified, and qualified rate of concentration simulation reaches 82.3 percent. The coefficient of determination is high, and its precision grade is second-grade. Consequently, it suggests that the forecasting scheme based on this paper can be used to issue the final prediction.(3) Conventional dispatching methods of Yingnahe reservoir consider flood pre-discharge, but the pre-discharge rule is not clear. For this reason, utilization of the accumulated net rain information to make the pre-discharge rule is required, or develop the flood forecast operation. First of all, the runoff forecast errors are not considered, and dispatching rules are established based on the cumulative net rain and the measured flow from the perspective of flood control safety and security of water supply flood. Then runoff forecast errors are considered, the dispatching rules are revised under the condition of mainly guarantee of flood control safety. And the influence of revising result for water supply security is analyzed.Finally, the summary is given, and some issues to be further studied are discussed.