松花江流域营养盐的空间分布及污染等级评价

应用综合污染指数法,结合2013—2014年对松花江流域进行水生态野外全面调查的结果,将流域内历时2年所调查的122个采样点的营养盐分为5个等级进行评价,分析流域内营养盐的污染状况及空间分布。结果表明:松花江流域营养盐评价等级(极好、好、一般、差和极差)的比例分别为10.66%、15.57%、20.49%、28.69%和24.59%,支流的评价结果明显好于干流;各子流域的营养盐污染程度排序为松花江干流>第二松花江>牡丹江>嫩江。研究区内土地利用类型与营养盐评价结果关系密切,尤其是农业非点源污染对流域含氮营养盐的影响较为显著。

Spatial Distribution and Pollution Level Evaluation of Nutrients in the Songhua River Basin

In this research, 122 samples were obtained from the Songhua River Basin to investigate spatial distribution and pollution of nutrients in river water using the comprehensive pollution index method in combination with the results of the 2-year field survey of aquatic ecosystems from 2013 to 2014. The results showed that the percentages of the excellent, good, moderate, poor and terrible grades of nutrient assessment were respectively 10.66%, 15.57%, 20.49%, 28.69% and 24.59%. The lowest scores of nutrient assessment were found in the Nenjiang River, the Mudan River, the Songnen Plain, the Sanjiang Plain and the Second Songhua River Basin. Nutrient pollution was less in the tributaries than in the main streams. The pollution of the nutrients in river water was in order of the main stream of the Songhua River >the Second Songhua River >the Mudan River >the Nen River. The three nutrient indicators(TN, TP and NH₃-H) were significantly different. The assessment method based on grades divided by the same standards was feasible. Land use had profound impacts on nutrient pollution in river water, especially the non-point source pollution of agriculture that affected nitrogenous pollution more significantly.