Study On River Floodwater Resources Utilization In Plain Area

The conflict between Water shortage and flood disaster exists in many areas of China. Flood resource utilization is-one, of the most important measures to resolve the problem. However, floodwater utilization will result in both risks and benefits since flood has the characteristics of hazards and resources. Therefore, risk analysis is a necessary work to ensure that floodwater is used under low risks and high efficiency.The paper has focused on the plain area floodwater utilization according to several floodwater utilization patterns in the middle-downstream of Nenjiang River. The main contents and research progress are as follows:(1) Method of floodwater utilization in plain area: Study the condition of runoff compensation based on the unequal distribution of water resources in time and space, and make full use of hydraulic engineering to relocate the floodwater in the whole river basin. Try to import the flood of Main branch of Nenjiang River to Moon-lake Reservoir and import the Taoer River flood to swamp, reservoir, grassland and so on to weak the bad influence of the shortage of downstream Taoer River.(2) Hydrological forecasting application in floodwater utilization: time and amount of flood are uncertain, and floodwater utilization is a complicated process. So floodwater utilization circulated in low efficiency for the risks brought by them. To reduce the risks, hydrological forecasting was researched and applied in course of floodwater utilization in this dissertation. Long-term runoff forecasting was applied in utilization preplan making. Based on the flood peak flow and time forecasted, floodwater diverting plan and emergency counter plan were made correctly. Application of flood forecasting in floodwater utilization real time management is effectively. Based on the exact results of flood forecasting, floodwater was stored in different area safely. In this paper, a successive multivariate linear regression model on concept of physical cause of formation for long-term runoff forecast was set up and flood forecast model were set up and applied in Baching floodwater utilization system.(3) Risks and benefits analysis of floodwater utilization in plain area: floodwater utilization will result in both risks and benefits since flood has the characteristics of hazards and resources. Therefore, the paper has studied risks and benefits brought by different size of flood. First, the risk factors are made clear after fully understanding the floodwater utilization system. Since different floodwater utilization ways cause different risks, then secondly, the potential benefits and losses brought by different flood amount in different calculated units are discussed, which are helpful to conduct the floodwater utilization. At last, the paper has studied the risk of importing floodwater into swamp, reservoir, and grassland in Baicheng City.(4) Optimal decision of floodwater utilization in plain area: floodwater utilization is restricted by flood process, flood peak and the risk. In order to rise up the utilization efficiency, the optimal decision of floodwater utilization is studied. The paper has set up an optimal model Of floodwater utilization taking account of the objectives of economy, society and environment. The risks and losses in each calculated units are determined, and the best allocation plan of Baicheng City is given with the maximum benefit under proper risk.(5) Strategy of plain area floodwater utilization: The development process of floodwater utilization typically consists of three stages, plan, and utilization preplan making and real time management. Floodwater utilization plan mainly focuses on the analysis of the local water demand, the flood characteristics and the flood control patterns of the hydraulic projects. Different floodwater utilization method should be conducted according to different size of flood. In the utilization preplan making step, the data of flood can be gain by middle and long-term flood forecasts, and the water system should be analyzed. By optimal calculation, the optimal decision of floodwater utilization and the emergency treatment can be known. Real time management is to select the allocation plan of floodwater resources and run it properly, based on the advanced real time predict and information transferring.At last, the paper has given some conclusions, as well as the questions which still need a further study.