Spatio-Temporal Variation Analysis of Precipitation during 1960-2008 in the Poyang Lake Basin, China

Abstract

Long-term monthly precipitation data from 1960 to 2008 at 17 rain stations are analyzed to explore spatio-temporal variation of the seasonal and annual precipitation in the Poyang Lake basin, China, using anomaly analysis, simple linear regressive technique, Mann-Kendall trend test and Continuous Wavelet Transform. The results indicate that: (1) increasing precipitation trend is observed in summer and winter, while decreasing precipitation trend is identified in spring and autumn, and the above mentioned precipitation trends are not statistically significant; (2) changing trend of the areal average annual precipitation is non-significantly increasing, and increasing trend happens in almost the whole basin except in western and south-eastern small parts; (3) the spatial distribution of the seasonal and annual precipitation anomalies between 1991-2008 and 1960-2008 is similar to that of seasonal and annual precipitation trend during 1960-2008; (4) three main time-frequency distributions are observed in annual precipitation series during 1960- 2008, and they are 18 - 26 years, 8 - 14 years and 2 - 8 years, respectively; accordingly, there are three main periods in annual precipitation series, and they are 11-year, 22-year and 5-year respectively. This result will be helpful for further research on availability, scientific management and assessment of the water resources of the Poyang Lake basin.