Multiple temporal scale analysis of main driving factors of eutrophication in Meiliang Bay, Lake Taihu

Abstract

采用太湖湖泊生态系统研究站太湖梅梁湾富营养化四种主要驱动因子叶绿素a(Chl.a)、水温、总磷(TP)、总氮浓度1992-2010年的监测数据,利用小波变换方法,分析了四种因子不同时间尺度上的时间格局特征.结果表明,四种驱动因子在年际和年代际尺度上都具有清晰的多时间尺度特征,主周期各不相同,但Chl.a和TP浓度的小波实部变化趋势具有较高的一致性.本文分析了各因子在不同时间尺度上的强弱分布以及高低交替,并在此基础上从时间尺度的角度预测出在未来3~5年内,太湖梅梁湾湖区的富营养化程度将保持在一个比较平稳的水平,为太湖富营养化的认识和治理提供更加可靠的科学依据.;Concentration of chlorophyll-a (Chl. a), total phosphorus (TP), total nitrogen and water temperature are the four main driving factors resulting in eutrophication in Meiliang Bay, Lake Taihu. Based on the observation data in the period of 1992 -2010, the temporal pattern characteristics of the four factors in different temporal scales were analyzed respectively using wavelet analysis. Results showed that the temporal patterns of the four factors were obvious in the inter-annual and inter-decadal scales and the primary periods were different, but the real parts of wavelet coefficients of Chl. a and TP were consistent. The distributions and the periodic oscillation were analyzed and it was predicted that the eutrophication condition in Meiliang Bay would keep stable in the future 3-5 years. This method will provide reliable scientific evidence to the management of Lake Taihu.