滨江流域降水周期及趋势分析

Analysis of Precipitation Cycles and Trend in the Binjiang River Basin

降水的周期和趋势变异分析对区域水资源管理具有重要意义。以珠江流域北江一级支流滨江流域控制性水文站珠坑站1965~2011年逐日降雨资料为基础,采用Morlet小波分析和Mann-Kendall趋势检验法,分析了该流域年、汛期和非汛期降水量的周期、趋势变化和突变点。结果表明:年降水量存在24年、9年和5年左右的主周期,汛期降水量周期与年降水量周期基本相同,非汛期降水量存在12年和5年左右的主周期;年和汛期降水量呈显著性减少趋势,非汛期降水量呈微弱减少趋势;2011年年和汛期降水量处于偏丰期,非汛期降水量处于偏枯期,预计2015年左右年和汛期降水量将进入偏枯期,非汛期降水量将进入偏丰期;年和汛期降水量在1966年左右发生显著性突变,非汛期降水量在1979年发生显著性突变。

Analysis of precipitation cycles and trends variations is very important for regional water resource management. This paper is based on the daily precipitation data during 1965-2011 from Zhukeng controlling hydrologic station of Binjiang River Basin—the first tributary of the North River in the Pearl River Basin, and adapted from the Morlet wavelet analysis and Mann-Kendall trend test to analyze the cycles as well as the trend variation and catastrophe point of the annual, flood season and non-flood season precipitations over the Bijiang River Basin. The results show that annual precipitation exists in about 24, 9 and 5 years primary cycles;flood season precipitation cycle is similar with annual precipitation cycle;non-flood season precipitation exists in 12 and 5 years main cycles. The annual and flood season precipitations show a significant decreasing trend, but non-flood season precipitation shows a weak decreasing trend. The annual and flood season precipitations were in sufficient period and non-flood season precipitation was in insufficient period in 2011, which indicates that annual and flood season precipitations will enter the dry period and the flood season precipitation will enter the abundant period around 2015. Significant mutations of the annual and flood season precipitations took place around 1966 and non-flood season precipitation in 1979.