Development Of Flood Forecast And Regulation System And Its Application To Hongze Lake

The Huaihe River is one of the greatest rivers in China. The Hongze Lake, located at the end of the middle Huaihe River, receives water confluence from a watershed area of 158 thousand km2 on the upper and lower Huaihe River, and acts as the junction of water volume regulation for the middle and lower Huaihe River. Accordingly, the State Department gave a specific instruction to ensure the safety of the Hongzehu Levee. In fact, the safety of flood control of the Hongze Lake is of great significances to the lower Huaihe River in Jiangsu Province. Therefore, the implementation of the study on the flood forecast and regulation system-an important nonstructural measure for decision making in flood control, is no doubt to be a necessary and urgent work. In this paper, some attempts have been made, and some satisfactory results have been achieved.Based on the meteorologic and hydrological characteristic of the upper Hongze Lake, a real-time flood forecast model was developed for this area by use of the three-water source model of the Xin'anjiang River. In consideration of some specific problems, such as the large watershed area, the inhomogeneous spatial distribution of underlying surfaces, and great influences of hydro projects on the regularity of rainfall runoff, some methods were adopted in the present model, including the division of subcatchments, calibration of parameters by full use of the measured hydrological data, introduction of experts' experiential data to model calculation, and also the man-machine interaction method. In this way, a rainfall runoff forecast model for large river basins was established.A comprehensive analysis shows that the flood control decision-making depends on the application of the operation system. In this work, the process of decision-making was generalized and simulated. With combination of the forecast system and operation system, a flood forecast and operation application system for the Hongze Lake was successfully constructed. The system played an important role in successful control of 2002's moderate flood of the Huaihe River, especially 2003's Huaihe River flood-the second greatest flood since the foundation of the People's Republic of China.Finally, some suggestions have been made about the improvement of the present system and its further development.