摘要
利用鄱阳湖流域16个气象站1960～2008年共49a的月降雨资料，采用Morlet小波函数，对该流域降雨季节变化、年际和年代际时间序列进行小波分析，揭示了流域降雨变化的多时间尺度特征，分析了不同时间尺度下降雨序列变化的周期和突变点。研究表明：①1960～1990年，年降雨量呈明显年际和代际振荡，并无显著趋势；进入90年代以后，年降雨呈现显著上升趋势；进入21世纪，尤其从2002年开始，年降雨量开始减少；②流域季节降雨和年降雨都存在多时间尺度特征，夏季降雨、冬季降雨和年降雨都存在18a的第一主周期；春季、冬季和年降雨存在6a次主周期；此外，春季、秋季、冬季和年降雨均存在3a次主周期；③夏季降雨在18a时间尺度上与年降雨变化具有相同的趋势和相位，春季降雨在3a和6a时间尺度上与年降雨变化具有相似趋势和相位变化。
A total of 49 years of monthly rainfall data in 16 meteorological stations in Poyang Lake basin during 1960 to 2008 was analyzed by Morlet wavelet function. The rainfall seasonal, interannual and interdecadal time series analysis results were used to reveal the multiple time scale features of rainfall change, and the periodic variation and mutation points of rainfall sequences at different time scales. （1） Annual rainfall showed obvious interannual and decadal oscillations during 1960 to 1990, no significant trend, but the annual rainfall had a significant increasing trend after entering the 1990s. The annual rainfall was decreasing from 2002.In general, spring rainfall had a decreasing trend during the study period and a decreasing amplitude of -11.03 mm/10 a; summer rainfall had an increasing trend and an increasing amplitude of 25.12 mm/10 a; autumn rainfall had a decreasing trend and a decreasing amplitude of -4.16 mm/10 a; winter rainfall had an increasing trend and an increasing amplitude of ll.85mm/10a.Annual rainfall had an increasing trend in Poyang Lake Basin and an increasing amplitude of 21.79 mm/10 a.（2） Both seasonal and annual rainfall had multiple time scale features, and there was 18 a first principal period in summer, winter and annual rainfall. Annual rainfall experienced three circulations from few to more on 18 a time scales, and the mutational point happened in the year of 1970, 1980, 1992 and 2003.At present, annual rainfall is in the less period. There is 6 a second principal period in spring, winter and annual rainfall. In additional, there is 3 a third principle period in spring, autumn, winter and annual rainfall.（3） Summer and annual rainfall had the same trend and phase changes in the 18 a time scale,while the spring and annual rainfall had similar trend and phase changes in 3 a and 6 a time scales. In 6 a time scale, change rule of spring rainfall and annual rainfall was more similar than that of summer rainfall and annual rainfall. The corresponding relationship was different between changing pattern of spring and annual rainfall and that of summer and annual rainfall in different time scales, and smaller was the time scale, smaller was the phase difference.（4） The seasonal changes trend in the study period was followed the order of Spring〉summer〉 autumn〉winter in the 1960s, 1970, 1980 and 2000s.Annual rainfall in the 1990s was obviously more than other periods, which was caused by that summer rainfall was greater than spring rainfall and winter rainfall was greater than autumn rainfall.
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2014年第3期434-440,共7页
Resources and Environment in the Yangtze Basin
基金
国家自然科学基金项目(41001158
41271500)
中国博士后基金项目(20090461148)
虚拟地理环境教育部重点实验室开放基金项目(2010VGE05)
关键词
鄱阳湖
年降雨量
小波分析
多时间尺度
Poyang Lake Basin rainfall wavelet transformation multiple time scale
