Study On Real-time Regulation Of Flood Resources Utilization In Liaohe River Basin

China’s water resources are unevenly distributed in time and space,floods occur frequent ly,and the contradiction between supply and demand of water resources is prominent.As a non engineering measure for the safe utilization of flood resources,reservoir regulation is an important means and practical choice to alleviate the resource-based water shortage in China.With the continuous improvement of rainfall forecast level and accuracy,rainfall forecast information has been widely used in the operation of a single reservoir.Compared with single reservoir,the forecast period of rainfall forecast information required for joint regulation of reservoir groups is longer,but the longer the forecast period is,the lower the accuracy may be.Therefore,how to use the rainfall forecast information and other information at the moment to carry out compensation regulation of reservoir groups and improve the flood control and water supply capacity of the whole system is the key and difficult point of joint regulation of reservoir groups.Therefore,this paper takes the three control reservoirs in the Liaohe River Basin as the research object.By analyzing the runoff variation law,the compensation and regulat io n capacity of inter basin runoff and the availability of collective rainfall forecast information,this paper carries out the research on the real-time regulation of flood resources utilization in the Liaohe River Basin by coupling the multi-scale rainfall forecast information.The main research contents and conclusions are as follows:(1)Analysis on variation law and compensation characteristics of inflow runoff from three controlled reservoirs in Liaohe River Basin.Firstly,by analyzing the characteristics of Liaohe River Basin Project and water use,the distribution of water users and the characteristics of project compensation,Dahuofang reservoir,Qinghe Reservoir and Chaihe Reservoir are determined as the research objects of Liaohe River Basin flood resources regulation project;Secondly,the Sen slope estimation method,Mann Kendall rank correlation test method and Spearman rank correlation test method are used to analyze the Inflow Runoff Trend of each reservoir and the change law of runoff distribution in the year,flood season,site flood and after the key period of regulation decision;Finally,based on the joint distribution model of Copula function,the wet and dry encounter characteristics between backbone reservoirs in the year,flood season and after the key period of regulation decision-making are analyzed.The results show that there is a common water supply target between Dahuofang reservoir and qingcha i reservoir group,which can improve the flood control and water supply capacity of the system through runoff compensation.(2)Study on the availability of rainfall forecast information in real-time regulation of flood resources utilization.Firstly,according to the rainfall characteristics from June to September in the flood season,the Dahuofang reservoir,Qinghe Reservoir,Chaihe Reservoir,Qing Chai combination and Liao Hun combination are divided into different magnitudes of rainfall;Then,using the method of mathematical statistics,the accuracy,missing rate and empty rate of rainfa ll forecast information in different watershed ranges and different time scales are analyzed,the frequency of actual rainfall distribution under different orders of magnitude is analyzed,and the distribution frequency of actual rainfall in different periods of time in the future is analyzed;Finally,the accuracy distribution in different ranges is compared and analyzed,and the available methods of rainfall forecast information in the real-time regulation of flood resources utilization are studied.The results show that the longer the statistical period in the future,the greater the available rainfall is when the large number of orders are predicted in 24h;Under different orders of forecast,the larger the forecast area,the higher the available rainfa ll.Coupling rainfall forecast information of different scales can be used for real-time regulat io n of flood resources utilization of reservoir groups.(3)Study on real-time regulation of flood resources utilization in Liaohe River Basin.First of al,a flood process is divided into three stages:the pre rising stage,the rising stage and the retreating stage.Then,according to the analysis of runoff characteristics of reservoirs in the Liaohe River Basin and the research results of rainfall forecast utilization methods,the two-stage decision-making model of pre storage and pre discharge of reservoirs in the rising and fal ing stages of flood is established,and the multi-scale rainfall forecast information and longer-term inflow runoff statistical information are coupled to formulate flood resource utilization and control strategies for three controlled reservoirs in the Liaohe River Basin.Finally,taking the"20100731"and"20100806"floods in the 2010 flood season as examples,the application research on flood resource utilization and regulation of three controlled reservoirs in the Liaohe River Basin is carried out,and the results are compared with the conventional operation results.The results show that the flood resources utilization regulat io n strategy of the three controlled reservoirs in the Liaohe River basin can be used in real-time regulation.The new regulation method is used to guide the reservoir operation.Compared with the conventional regulation,the maximum reservoir water level is reduced and the maximum discharge of the reservoir is reduced on the premise of ensuring the safety of water supply;On the premise of ensuring flood control safety,the end water level of flood regulation was raised,and the utilization of flood resources was effectively increased by 79×10~6m3.Finally,the full text is summarized,and the problems to be further studied are prospected.