Analysis On The Annual Maximun Discharge Of The Four Main River In Dongting Lake Region

It is one of the places where were suffered most seriously by thedisater of flood and water-logging in Dongting Lake region.There areso many fives in the region, and so, it is one of the palace with themost complicated hydrolodgical regimes for the relationship betweenwater and sand,riveres and lakes.The resoures of water for theDongting Lake,however, is the Xiang river, Zi river, Yuan river and Liriver, which has surpassed the quantity of water from the Long river inrecent years,esspecially after the Three-Gorge reservior has beenbuilt.then the contradicton between the four rivers and contradictionbetween the four rivers and Dongting Lake will be the dominantcontradictions in the Dongting Lake drainage area,and the peakdischarge and the frequent encounter of flood peak of four rivers isthe direct cause of the disaster of flood and water-logging.Based on the wavelet analysis theory, Mann-Kendall mothed andR/S analysis theory, the periodical change, tendency, and theconstancy and inconsitancy of the tendency and the jumping points ofthe temporal series of the annual maximum discharge from1951～1995 of the four rivers from the temporal series is studied. Theresult showes that: the annual maximum discharge of Xiang river, Ziriver, Yuan river and Li river fluctuate with the multiple temporal scaleof 10 years,23 years,18 years,21 years,8 years,15 years,18 years, 21years,and the tendency of the Xiang river and Yuan river is quitestable,however, the Zi river and Li river showes a rapidly desendingtrend.and which shows an tendency of inconstantcy by the R/Sanalysis. and the jumping points appeared in the 1950s.Phase space is rebuilt and the systemic saturation embeddingdimensions and correletive dimensions is caculated in this paper byG-P mothed. it is showed that the correletive dimensions is not ainteger, and the scaleless range is very clear in the fig.ln Cm(r)-ln(r);it shows that chaotic characterists existed in the seriesof the annual maximum discharge.At the end of this paper the characterists of the encounter of theflood peak and the infection to the four main rivers fromThree-Gorge reserviorThe series of the annual maximum discharge is thoroughly analyedin this paper which have promotion effect to recognise thehydrolodgical regimes and the disaster of flood and waterlogging.