Studies On Characteristics Of Annual Runoff In Anning River

Wavelet Analysis is a newly and rapidly developed technology in the field of time-frequency analysis recently, and it has the characteristics of multiple temporal scales, multiple hierarchical analyses, and multiple solution powers. The paper is based on long time series hydrologic data and meteorological data about Anningqiao hydro-entrance station and wantan hydro-exit station of Anning River Basin during 1957～1985.Wavelet analysis and statistical analysis are used to study on the interrelation among climate and runoff variation, and they are also used to analyze and predict the multi-time scale variation features of climate and runoff as well as the future variation trend. The result indicates that as below:The inter-annual distribution of the runoff was extremely uneven and the annual runoff varieties slightly. The main conclusion is that the runoff variation in the basin was affected greatly by the precipitation changes and the temperature and evaporation variation were not the main causes leading to the runoff variations.The study region's climate and runoff series have the characteristic of multi-time scales changes. The temperature series exists 2.5a,8.5a and 15.5a quasi-prime period; The precipitation series exists 2a,5.5a quasi-prime period; The evaporation series exists 2.5a,8.5a 18a quasi-prime period; The runoff volume series exists 2a,5a,8.5a and 15.5a quasi-prime period. There is a timeliness of quasi-prime period, which means only in some specific time.There is a variation trend of temperature series in the study region after 1985:it was colder period during 1986～1988 ,and warmer period during 1989～1990;The variation trend of precipitation series is as follows: it was more-precipitation period during 1986～1989,and less-precipitation period after 1990; The evaporation series's variation trend is as follow: In 1986～1989, 1992～1994, the evaporation would decrease and in 1990～1991, the evaporation would increase; The variation trend of runoff volume is as follow: it was relatively excessive in 1985～1987, relatively insufficient after 1987.