成都市1951～2010年降水量多时间尺度分析

Multiple Time Scales Analysis of Annual Precipitation in Chengdu from 1951 to 2010

近年来随着成都市经济的飞速发展,各行各业对水资源的利用不断加剧,因此准确预测成都市降雨的变化趋势,科学合理地配置水资源显得尤为重要。小波变换不仅能清晰地呈现出各种时间尺度的强弱、分布情况,而且能分析其主要周期,进而预测降水量的变化趋势。本文基于小波分析法对成都市1951～2010年的年降水量序列的变化特征进行了分析。结果表明,成都市年降水量在其计算时域内各时间尺度分布不均匀,具有明显的局部化特征;其中21～35年时间尺度发生区域贯穿整个60年,12～20年的时间尺度主要发生在1955～2010年,8～10年的时间尺度变化主要发生在1960～1973年和1980～2010年,7年左右的时间尺度变化主要发生在1953～1978年。分析趋势表明,未来10多年内成都市的降水量仍会减少。分析小波方差得出成都市年降水量具有4年、7年、14年和27年的主周期,其中27年为第一周期。用Yamamoto检验法检验突变,结果显示近60年来成都市年降水量没有发生突变。

In recent years, with the rapid economic development in Chengdu, the use of water resources continues to accelerate in industries. So it is particularly important to predict the trend of precipitation accurately and allocate water resources scientifically and rationally. The wavelet transformation not only dearly shows the strength and distribution of various time scales, but also analyzes the main cycle of precipitation, therefore can be used to predict the trend of precipitation. The variation characteristics of the annual precipitation in Chengdu from 1951 -2010 were analyzed by using wavelet transformation method. The result shows that annual precipitation in Chengdu presents a non - uniform time - scale distribution in its calculation period with obvious localization characteristic. 21 -35 year scale occurred throughout all the 60 year period, 12 -20 year scale mainly occurred during the periods of 1955 -2010, 8 - 10 year scale mainly occurred in the period of 1960 - 1973 and 1980 -2010, and the time scales of about seven years occurred in 1953 ~ 1978. The trend analysis shows that in the next decade Chengdu precipitation will continue to reduce. The analysis of wavelet variance shows that the sequence of precipitation in Chengdu has a main period of 4 years, 7 years, 14 years and 27 years, with the period of 27 years being the first primary period. Yamamoto inspection method is used to inspect the abrupt change and the consequence shows that there wasn＇t any abrupt change in the past 60 years time in Chengdu.