Study Of Rainfall Forecast Information In Liaohuntai Basin

Water is one of the most important and irreplaceable resources in our production process and daily life.Nowadays our country is facing serious water problems.In order to effectively alleviate the shortage of water resources,it is very important to apply the hydrological forecast to the reservoir management.However,the lead-time of effective flood forecast is relatively short,so that it is necessary to take rainfall forecast into consideration when we do research on flood dispatching.In view of the prediction error in rainfall forecast,how to make use of rainfall forecast information reasonably has been a popular topic for researchers.Through Contrasting and analyzing different TIGGE rainfall Ensemble forecast products,This paper chooses CMA、NCEP and ECMWF rainfall ensemble forecast products as research objectives and analyzes their availability in Liaohunai basin.The main research results are presented as follows:(1)Combining the known rainfall standards of 12 h and 24 h,we verified the availability of P-Ⅲ curve and normal distribution.Then we choose the better method to divide the rainfall levels of 48 h,120h and 240 h scientifically and accurately on the basis of satisfying the fitting standard.And then we calculate the average rainfall of 6h,48 h,120h and 240 h of each reservoir,also we divide them according to the rainfall level as well(2)This paper studies the availability of rainfall forecast information in short-term(6h,12 h,24h and 48h)watersheds in Liao,Hun and Tai River basin combined with short-term rainfall and reservoir flood control in the period of 2008 to 2015.We choose the rainfall forecast data to analyze the accuracy and the "three rate" information to obtain the best forecasting institution.Then we choose the III,IV and above levels of real rainfall of this institution as the object of this study,Moreover,we select the 85%,90% and 95% of the rainfall corresponding to the actual rainfall frequency to analyze the availability of short-term rainfall forecast information.The utilizability of rainfall forecast information for the expected period of 24 h and 48 h in Tanghe reservoir is very good;the utilizability of rainfall forecast information in Guanyinge reservoir is very poor;and that of Shenwo reservoir for the expected period of 48 h is relatively good;the efficiency of the ECMWF mechanism in the Dahuofang reservoir is the best,and the utilizability is not good;The overall availability of rainfall forecast information in Chaihe Reservoir is not strong;The utilizability of rainfall forecast information of the fourth and above the magnitude fin Qinghe Reservoir is good.(3)This paper also studies the availability of rainfall forecast information in medium-term(120h,240h)watersheds in Liao,Hun and Tai River basin combined with medium-term rainfall and reservoir flood control in the period of 2008 to 2015.We choose the rainfall forecast data to analyze the accuracy and the "three rate" information to obtain the best forecasting institution.Then we choose the I,II,III and above levels of real rainfall of this institution as the object of this study,Moreover,we select the 85%,90% and 95% of the rainfall corresponding to the actual rainfall frequency to analyze the availability of short-term rainfall forecast information.The utilizability of rainfall forecast information in Tanghe reservoir is very good,especially rainfall forecast information for rainfall in level I and II;There is no shared capacity in the Guanyinge reservoir,so the availability of rainfall forecast information is not discussed.The utilizability of rainfall forecast information for the expected period of 48 h is good,especially the rainfall in level III and above.The forecast information of the Dahuofang Reservoir in level I and II is of little utilizability.The forecast information of Chaihe reservoir is of great utilizability,especially for the expected period of 120 h forecast;The forecast information of Qinghe reservoir is of great utilizability,especially for the expected period of 120 h forecastFinally,we summarizes the results of this paper,and points out the shortcomings in this study and the future research direction.