沅江干流水质变化时空规律及五强溪水库库区总磷预测

对五强溪水库上游沅水干流近年水体水质情况进行分析,个别污染物的影响导致沅江干流水质逐渐恶化,且沅江干流的主要污染物由粪大肠菌群变为总磷.采用灰色模型GM(1,1)及一元线性回归模型对沅江干流中五强溪库区的总磷浓度变化进行拟合,灰色模型的精度远高于一元线性回归模型.采用灰色模型建立五强溪库区总磷浓度变化的预测模型表明,五强溪库区的总磷污染形势十分严峻.

Analysis of Yuan River water quality with a forecast of TP concentration in Wu Qiangxi Reservoir

The present article aims to give an analysis of the water quality of the upper reach of Yuan River before it merging to Wu Qiangxi Reservoir in the past few years.Our analysis reveals that the water quality of the river has become worse,the situation of which is caused by one or two kinds of contamination.The chief contaminant was once fecal coliform bacteria,and now turns to be the total phosphorus.Most of the data given by the investigation stations show that Yuan River has been polluted and the pollution situation is getting worse and worse from 1999 to 2005.However,as the river reaches its lower reach,the pollution situation proves to less serious.At the Wu Qiangxi Reservoir the water measures up to the secondary surface quality standard.But the effect of contamination of the total phosphorus is cumulative,and,therefore,it is necessary to investigate the TP concentration in the reservoir.Grey model GM(1,1) and the linear regressive model are adopted to fit the change of the total phosphorus concentration of Wu Qiangxi Reservoir.Since the precision of the GM model is much higher than that of the linear regressive model,the forecasting model built based on the GM model indicates that the total phosphorus pollution is serious in the Wu Qiangxi Reservoir.As the Forecasting results show,it should really pay special attention to the phosphorus pollution in Yuan River,otherwise,it would badly affect the environment of the drainage area with negative influence to the development of Huaihua,even Hunan on the whole.