Analysis on Climatic Characteristics of the Precipitation Anomaly in Southwest China in Recent 60 Years

[Objective] The research aimed to analyze temporal-spatial distribution characteristics of the precipitation anomaly in southwest China from 1951 to 2010. [Method] Based on monthly precipitation data at 44 stations of southwest China and 160 stations of China from 1951 to 2010, by using EOF analysis, wavelet analysis and composite analysis, monthly and seasonal change rules of the precipitation in southwest China were analyzed. Corresponding spatial-temporal distribution characteristics of the precipitation in drought and flood years were studied. Temporal-spatial distribution characteristics of the precipitation anomaly in southwest China in recent 60 years were revealed. [Result] Seasonal distribution of the precipitation in southwest China was uneven and was typical single-peak type. Precipitation concentrated from May to September, and peak appeared in July. In recent years, rainfall in autumn significantly became less, while that in other seasons had no obvious change. Precipitation in summer had the cycle of 14 years, another for 6 years and 3-4 years of periodic oscillations. In wet years, precipitation in southwest China had same phase with that in southern China, and anti-phase with that in the junction of Qinghai, Gansu, Xinjiang and Tibet. In dry years, precipitation in southwest China had same phase with that in the eastern part of northwest China and northern China. [Conclusion] The research provided reference basis for prediction and pre-warning of the precipitation in the zone.