Operation Theory On Multi-purpose Reservoir And Its Application To Shitouhe Reservoir

Abstract: It is the foundation of human life and social progress and the importantguarantee for sustainable development of national economy to exploit and use waterresources reasonably and prevent flood and drought disasters. Multi-purpose reservoir isone of the main enginering measures on flood control and drought combat. Its scientificoperation plays an important role on water supply and flood control. Reservoir operation isa multi-objective decision-making problem that are affected by many factors such as rainfall,engineering status and decision-maker, in which decision variable is discharge (watersupply and flood discharge), the input is reservoir inflow, the status is reservoir storage. Theoperation theory of multi-purpose reservoir is studieded and applied to Shitouhe Reservoir,in which the flood limit water levele is main line and the beneficial operation is objective.Main research contents and results achieved are as follows:(1) Prefer the Fisher optimum spliting method on flood season staging by usingcorrelation of rainfall-runoff during flood season as indicator, then taking a comparativeanalysis with fuzzy statistics method,which have indicators of day-by-day precipitation,day-by-day runoff, and flooding occurred time, method of point-varition analysis and fractalmethod. Result shows: Fisher optimum flood season staging method based on correlationcoefficient in line with theory of runoff formation, has the ability of consideration onvarious indicators and the combination of sequential phased, result comes from it isobjective and reasonable, thus has a certain value. Based on this method, flood season ofShitouhe reservoir has been divided into five stages: transition period before flood season(April1–May20), rainy season (May21–July10), main flood season (July11–August10), the season after flood season (August11–September20) and transition period afterflood season (September21–October31).(2) Focus on the characteristic of less data on different flood periods, study is carry outon relationship between flood processes and daily flow processes, prefer the correlationanalysis of interpolate extension method elements of stages flood based on average dailyflow series. Application in Shitouhe reservoir indicated that the method has a strongpractical value.(3) Analysis the adaptability by using the method of probabilities point with designingpeak flow of different flood stages and flood volume probability distribution in different statistics timing as way,on normal distribution, lognormal distribution, Pearson Ⅲdistribution, log-Pearson Ⅲ distribution, type Ⅰ extreme value distribution andexponential distribution. Result shows: stages frequency distribution of peak flow pattern aredominated by logarithmic type distribution, considering the first advantage distribution and the secondadvantage distribution, determine that each installment flood elements frequency curve of Shitouhe basinis logarithmic normal distribution.According to this, designing flood of Shitouhe reservoir hasbeen calculated by using typical flood frequency scale method.(4) Analysis the applicability of reservoir flood adjustable calculus principle whichbased on trying algorithm and fuzzy collection law based on statistics analysis on limitedflood level calculation in different flood staging, results are: fuzzy set legitimate analysis oflimited flood level process shows "centre down " curve, trying algorithm analysis of limitedflood level process show a shape of stepped line; fuzzy set legitimate analysis is comparisonsensitive on threshold value of indicators, unfit to use for calculation in non-main floodseason, and trying algorithm method has consolidated theory foundation, limited flood levelcome from it can be used easily in actual reservoir scheduling. From this, limit flood levelof Shitouhe reservoir is798.00m in flood season, and801.00m in non-main flood season.(5)Analysis in detail on random factors which causing overtopping, and discuss thedistribution type of these random variable factors, using method of designing flood-Maxuseable wind to calculate the overtopping risk model, get different overtopping risk valuesof Shitouhe reservoir flood. Take10-6as acceptable overtopping risk standard,limit floodlevel in flood season of Shitouhe Reservoir should be less than800.00m.(6) Established an optimization one-time scheduling model aimed to minimum totalwater lackage of reservoir in a flood adjustable period, put forward optimization two-timescheduling model which take the discharge procedure in one-time scheduling model aswater income of the reservoir, and target at maximum total generating capacity. Calculatethe model by using incremental dynamic planning method, result shows: on the basis ofone-time optimization scheduling model, result of two-time optimization scheduling modelresults in a great improvement on ensuring the optimization goal of generating capacity. Butadd to the present water supply object of Shitouhe reservoir, generating capacity increase nomore than2%when limited flood level rises from798.00m to801.00m in main floodseason.