Application Of Flood Simulation Model In Dongtinghu Watershed

Flood is one of the greatest nature disasters in China, which causes the highest annually average damages among various kinds of nature disasters. As a result flood simulation and forecast is of great significance for understanding flood and flood control. There are two types of methodologies, hydrological and hydraulic, for flood forecast. Based on the fact that Dongtinghu watershed is characterized by interlaced river network, turbulence of streamflow, linkage and disconnection of rivers and lacks and burst of embankment, this paper introduces a combined one-dimension and two-dimension hydraulic model in which one-dimension hydraulic model is used to simulate river flood flow and two-dimension hydraulic model is used to simulate lake flood flow. This flood forecast model serves as a scientific decision-making tool for synthetic management and flood control of Dongtinghu basin.The thesis includes five chapters, and main content of each chapter is as follows:In chapter 1, the natural and social situations of Dongtinghu watershed is described in brief, while the primary problems of flood control faced by studied watershed are analyzed in detail upon which the current study state of flood simulation of Dongtinghu is generalized.In chapter 2, we analyze the meteorological causes of flood, and investigate the concurrence of four main rivers and four main rivers versus Yangtse River. Flood characteristic is analyzed from its component point of view, and at the same time sediments of Dongtinghu Lake is calculated.Chapter 3 is emphases of the paper in which the dimension and algorithm are determined. We discuss five published hydraulic models: SMS, MIKE21, CH3D, ADCIRC and ID0R3D, from which SMS model is selected through comparison analysis based on actual conditions of Dongtinghu basin. The basin is separated into 40 parts in the model. We choose SSARR model as the hydraulic model of section flood forecast and address the basic principles and calculating procedure. Finally the model s parameters are calibrated.In chapter 4, application of flood simulation model in flood forecast is discussed with one-, two-, and three-day as forecast time intervals. The forecast results in each cross-section are of high accuracy as compared to observed water levels. And application of flood simulation model in flood optimal operation is analyzed briefly.Chapter 5 sums up the whole paper, analyzes some problems of the model and gives some constructive suggestions for future study.