基于灰关联和BP神经网络法评价黑河流域水质

Water Quality Assessment of Heihe River Basin Based on Grey Correlation Method and BP Neural Network

为探明黑河流域的水质状况,于2013—2015年每年的4月、7月和12月对黑河流域中的八宝河、野牛沟、北大河、梨园河、红水河、山丹河、张掖湿地、中游干流、额济纳河、东居延海小流域水体进行采样,测定溶解氧(DO)、氨氮(NH3-N)、总氮(TN)、总磷(TP)、高锰酸盐指数(CODMn)作为评价因子,采用灰色关联法和BP神经网络法对黑河流域水质状况进行综合评价。结果表明:BP神经网络法的评价结果较为符合黑河流域实际,八宝河、野牛沟、红水河水质良好,以Ⅲ类为主;北大河、梨园河、山丹河、中游干流、额济纳河水质较差,以Ⅳ类为主;张掖湿地、东居延海水质较差,常年为Ⅴ类,主要原因是营养盐和污染物富集,超出水体自净能力,造成水质状况较差。

Based on the investigation of the water environment factors of Heihe River basin which included Babao River,Y e 5 niugou,Beida River, Liyuan River, Hongshui River, Shandan River, Zhangye wetland, the main stream on the middle reaches, Ejina River and the East Juyanhai Lake in April, July and December each year from 2013 to 2015, the dissolved oxygen（ DO）, ammonia nitrogen（ NH3-N ）, total ni-trogen （ TN）,total phosphorus（TP） and permanganate index（ CODMri） were selected as evaluation factors for water quality,the method of grey correlation and BP neural network were used to evaluate the water quality of Heihe River basin. The results show that the water quality of Babao River,Ye’niugou and Hongshui River is mainly class Ⅲ,the water quality of Beida River,Liyuan River,Shandan River,the main stream on the middle reaches and Ejina River is mainly class Ⅳ,the water quality of Zhangye wetland and East Juyanhai Lake is class Ⅴ. The cause of poorer water quality of Zhangye wetland and East Juyanhai Lake is that the nutrients and pollutants are accumulated leading to water polluted and water self purification capability declined.