Precipitation Variation Characteristic Analysis in the Main Flood Season of Western Liaoning

Using statistical analysis methods,precipitation variation characteristion in main flood season of western Liaoning in 1953—2010 was studied.The results showed that:precipitation in main flood season of western Liaoning significantly reduced and climate tendency rate was-12.56 mm/10a,and existed the periodic variation of 8-9a and the quasi-periodic changes of 18a.Precipitation in main flood season occurred significant mutations in 1980,precipitation decreased by 12.5% after the mutation.Precipitation change in non-flood season was relatively stable,and had slightly increasing trend.