Study On Runoff Forecast Model And Methods Of Real-time Correction In Lower Reaches Of The Weihe Basin

Water resources, the rarest natural resources for human's survival, are important guarantee which support sustainable development. With the rapid development of social and economic, water shortage is becoming a constraint factor in the development of the region, the world and even the global. How to exploit and use the water resources rationally has become an emergent problem which should be solved, and runoff forecasting is the base and key in solving the water resource problem.The thesis is based on the project which belongs to hydrographic station of Yellow River Conservancy Commission; the name is "Research of Flood Forecasting Model and System Exploitation in the lower reaches of Weihe River". The research area is Zhangjiashan, Xianyang～Huaxian, on the basis of the analyzing the runoff and confluence characteristics, daily runoff forecasting model and real-time correction model in flood season in Huaxian is developed.Weihe River is the bigger branch of Yellow River, which locates in the sub humid and semiarid zone, there are many branches in this area, and the underlying condition is complex, the characteristics of runoff and confluence is uneven. From ninety decades, because there are some dry seasons in Weihe River, the rainfall reduced and the water consumption of national economy has increased gradually, the runoff has reduced, so as to the measured runoff in the main river has decreased, and the lower reaches stream of Weihe River has also atrophied. Both of there makes the runoff and confluence characters changed in this area.This paper firstly reviews the development of hydrology model and real-time correction, and then analyses the runoff change tendency in lower branch of Weihe River, the runoff inter annual change, the runoff allocation in one year and the frame and composition of the runoff in Huaxian station. On the basis of analyzing study area, daily runoff forecasting model in flood season in Huaxian is developed. Discusses the application of the Three-water Source Xinanjiang model in north branch of Weihe River which is sub humid and semiarid, and the application of the division sector and layer Muskingum method in the stream confluence in the study area. Through analyzing the result the model explains that the model is proper and credible. At the same time, analyzing the feature of the study area, this paper develops the runoff real-time model in Huaxian which is based on the error autoregressive model so as to increase the forecasting accuracy, and uses faded-memory least square method and kalman filter method to correct the forecasting runoff, also compares and analyses the results of the two methods. After corrected, the accuracy has increased, but the effect of kalman filter method is better than faded-memory least square method. The result indicates that the runoff forecast model and real-time correction model in the study area is feasible, so this model can be used in the similar area as reference.