The Analysis Of Precipitation Feature Of Nanchong Over The Past Three Decades

With the change of the global climate including the elevated temperature, abundant rainfall and increasing terrible weather,some aspects of humane life were influenced.Nanchong,locating in 30o35′~31o51′N and 105o27′~106o58′E,is in the basin of the Sichuan with a low terrain which theannualmean temperature was 17.4 degrees and the highest temperature congregated in 5 or 9 month.Under the setting of global climate change,I counted out a series of quantity such as:theannualand mensal mean rainfall,the maximum rainfall and the frequency of the storm through the data of the rainfall in 1981 to 2010 in Nanchong.Then I speculated the rainfall basing on analysis of the principal component,wavelets,the features of the period of rain and the annual regularity of rain.The research shows that there appears a normal distribution on the quantity of rainfall,the days of the rain,storm which congregated in the month of 5 to 9 in Nanchong.Nanchong monthly precipitation and temperature into a significant correlation, indicating that the temperature in Nanchong, a great impact on precipitation.The results of principal componentanalysisestablished the four principal components and classified the period of the year of 1981 to 2010 into four types by total quantity of rain and variation of the rainfall.There is an obvious oscillating period in annual(as 12 years)and mensal(as 5 years)average rainfall.In the future of 4 or 5 years,the rainfall will illustrate an increasing trend and then leading to a reducing oscillating period.