Statistic Analysis Of Temporal Characteristics Of Precipitation In Odra River Arena During The Past 40 Years

The Odra River flows on the European continent and flows mainly through the Lower Silesia of Poland.The Odra River Basin is characterized by a maritime transition to the continental climate temperate forest,and precipitation has distinct temporal and spatial differences.In this paper,the daily precipitation data of three important meteorological monitoring points in the Odra River Basin from 1971 to 2010 were analyzed by means of the Ensemble Empirical Mode Decomposition method,the Mann-Kendall method and so on.The trend of precipitation change and the annually precipitation change of the Odra River Basin and its three monitoring were analyzed systematically at different time scales.To explore the characteristics of climate change in the Odra River Basin,and to provide scientific theoretical basis for the study of regional water resources management and agricultural activities.Analyses the existing data analysis,this paper got the following conclusions:(1)The basic characteristics of annual precipitation in 1971-2010: the average annual precipitation of Odra River Basin in the past 40 years is 575.99 mm,the degree of dispersion is 16.9%;the annual precipitation coefficient skew coefficient is negative,which means that the degree of dispersion of the drought year is relatively large;the annual precipitation coefficient kurtis coefficient is negative,which means that the extreme weather conditions are less.(2)After using the Ensemble Empirical Mode Decomposition method,we know that the annual precipitation of the Odra River Basin shows a decreasing trend from 1971 to 1992,and the annual precipitation in the Odra River Basin shows an upward trend from 1992 to 2010.The use of spectral analysis to obtain its inter-annual cycle is 3.1-year and 5.5-year,the chronological period is 16-year and 29-year.(3)The three monitoring stations in the Odra River Basin experienced sudden changes in precipitation in 1976,1981 and 2009;Only one year of three monitoring stations has past the significant test,the annual precipitation trend is not obvious..