Characteristics Analysis of Precipitation Change in Yibin City in Recent60 Years

Based on the data collected by the Meteorological Observation Stations of Yibin city during the years of1955—2014 and by use of the linear analysis, the precipitation variation characteristics of Yibin city over the specified60 years were found out. At the same time, by calculating the H index to predict the tendency of the precipitation variability in the future, and the method of GM(1, 1) analysis was adopted to predict the possible years that precipitation disaster may occur for the city. The results show that: in the recent60 years, the annual precipitation of the city take a tendency of a fluctuating decline year by year, accompanied by an increasing frequency of drought. The Hurst of precipitation index is 0. 792, showing that the annual precipitation of Yibin city is of strong persistency, and the precipitation may undergo a tendency of continuing decline in the future. The likely drought years are around2018-2019, and that the flooding years may occur in2021-2022.