Study On Flood Resources Utilization In Plain River Network Area

The comprehensive enhancement of requirement of water resources from sustainable development of economy and society, not only requires increasing water supply amount, but also requires the higher water supply guarantee rate and the higher water quality standard. In most areas of China, the precipitation amount of flood season is account for 60%-80% to that of the year, that is to say about 2/3 water resources is flood runoff which is difficult to utilize, therefore the problem of flood utilization is more significant on the background of more serious conflict between water supply and water demand. Taking Beisan River net of Tianjin city for example, this dissertation is processed surrounding feasibility study of flood utilization, compensation characteristics of ample flow and low water, flood utilization in flood detention area, the simulation analysis of flood resources in plain channel, and flood utilization in plain river network. The main research contents and conclusions can be summarized as following:(1)The conception and arithmetic of theoretical, available, realized and to be exploited potentials of rain-flood resources are introduced for its dynamic characteristic. The calculation results show that: there are water resources conditions and engineering conditions, thereby it is necessary and feasible to carry out flood utilization job.(2)Using the Set pair theory and Copula function which are provided new way for compensation analysis, the compensation characteristics of precipitation, inflow runoff, inflow runoff and precipitation, outflow runoff is analyzed, through verifying each other, the result show that it is feasible and meaningful to prosecute compensation regulation in Beisan river network area for it's imperfect flood utilization pattern.(3)The loss caused by storing flood in detention basin should contain submerge loss and additional loss produced by encountering flood later, and"the expectation value of additional loss"is proposed to describe the average value of additional loss. Then the risk estimation index system of detention basin is constructed, the calculation method and judge criteria of relative risk are presented. At last, the loss and benefit of each water storage scene are calculated and with contrast of comprehensive risk value, relative risk value can enhance the decision-maker's risk consciousness and so as to corresponding management strategy can be proposed.(4)The connotation of flood utilization layout is described, comprehensive evaluation methods of the projects are summarized. Three layers runoff yield model on the plain area, which is coupled of full storage, excess infiltration and full storage, and 1-D unsteady flow computation model are applied to real-time regulation considering flood utilizing factor. Taking Dahuangpu detention basin as a representative area, the loss, benefit, and risk under storage water quantity of 7.08×106 m3 and 1.034×107 m3 are given out.