基于小波分析的断面污染负荷演变规律研究初探——以松花江哈尔滨段为例

Wavelet analysis based study on evolution law of sectional pollutant load——a case of Harbin Reach of Songhuajiang River

采用Morlet小波函数对松花江哈尔滨水源地站1999～2008年逐月断面污染物负荷量变化过程进行小波分析,以多时间尺度揭示10年间污染物负荷量年际变化关系。结果表明,1年、2年、5年时间尺度呈现强周期交替规律,3年、4年呈现弱周期交替规律。污染物负荷量年内变化与地表径流过程基本相符;受2005年松花江污染突发事件影响,该序列存在突变点。

Based on Morlet wavelet function, a wavelet analysis is made on the changing process of the monthly sectional pollution load from 1999 to 2008 obtained from the hydrological station of the water source for Harbin Reach of Songhuajiang River, and then the annual pollution load changing relationships within a period of 10 years are revealed on multiple time scales. The re- suit shows that a strong cycle alternate law is presented on the time scales of one year, two years and five years, while a weak al- ternate law is presented for three years and four years. Moreover, the annual changing of the pollution load is basically coincided with that of the surface runoff process. Nevertheless, a point of discontinuity is there in the time sequence due to the impact from the sudden pollution event of Songhuajiang River happened in 2005.