新丰江新丰段水环境质量时空分布特征及变化趋势分析

The Analyses of Spatiotemporal Distribution Characteristics and Changing Trends of the Water Quality of Xinfengjiang in Xinfeng Reach

新丰江是东江发源地之一,其水质好坏直接影响下游的供水安全.通过对2016—2021年新丰江新丰段4个监测断面的氨氮、总氮、总磷、高锰酸钾指数4个水质指标的月度监测数据进行统计分析,结果表明:新丰江水质总体优良,总磷明显下降,氨氮略有波动,总氮呈上升趋势;上游水质总体好于中、下游,各类污染物经过县城区域后显著升高,推断生活污水是主要污染源;中游至下游由于水体自净功能,污染物有所下降;新丰江水质不存在显著的季节性差异,但仍存在有规律的周期性变化,局部污染源的空间分布是水质变化的最主要原因.

Xinfengjiang is one of the important sources of Dongjiang, and its water quality determines the water supply safety in downstream areas. The ammonia nitrogen,total nitrogen,total phosphorus and permanganate index from four water quality monitoring sections in year of 2016—2021 were analyzed. The results were as follows:in general,the water quality of Xinfengjiang was good,and TP had an obvious decreasing trend,and NH4 fluctuated a bit wildly in recent years,while TN increased quite significantly. The water quality upstream was significantly better than that middle and downstream,and it was inferred that the domestic sewage was the major cause. The pollutant concentration decreased between the middle and downstream because of the self-purification of water bodies and the influx of other tributaries. The water quality of Xinfengjiang had no significant seasonal variations,but there were still some degree of periodic changes. The spatial distributions of pollutant sources mainly caused the variations of the water quality indexes.