东辽河上下游非点源污染特征对比分析

Comparative Analysis of Non-point Pollution Characteristics in East Liao River Upstream and Downstream

采用径流分割法估算东辽河下游非点源负荷，对比分析东辽河上下游非点源污染特征，为东辽河水环境治理提供科学依据。结果表明，东辽河下游非点源COD占比为61％-83％，非点源氨氮占比为55％～69％，均高于上游地区；这与同时期农业种植面积紧密相关。东辽河上下游非点源污染负荷年内分布不均，上下游非点源COD负荷与降水量、流量一致，峰值均为7月；与COD不同的是，上游非点源氨氮与降水量、流量一致，峰值7月份；但是下游因玉米种植面积大及8月份追肥的影响，下游非点源氨氮比降水量、流量滞后1月，氨氮峰值为8月份。

The runoff division method is applied to estimate the non-point load in East Liao River downstream and give a comparative analysis of non-point pollution characteristics in East Liao River upstream and downstream to provide the scientific basis for water environment governance of East Liao River. The results show that non-point COD load accounts for 61% -83% and non-point ammonia nitrogen load accounts for 55% -69%. Therefore non- point load of the downstream is higher than the upstream, which has a strong correlation with agricultural plant area. The inter-monthly variation of non-point pollution load is big in East Liao River upstream and downstream. Non-point COD load are both consistent with the precipitation and discharge and the peak are both in July in up- stream and downstream. But unlike COD, non-point ammonia nitrogen load is also consistent with precipitation and discharge and peak is in July in upstream. However, because of large acreage and fertilizer effect of the corn in Au- gust, non-point ammonia nitrogen load is one month later than precipitation and discharge and the peak lag of am- monia nitrogen load is in August.