东平湖水体中氮磷的分布特征及其富营养化评价

文章研究了东平湖水体中N、P的分布特征,并采用综合营养状态指数法对东平湖水体富营养化的现状进行了评价。结果表明,东平湖春季、夏季和秋季的水体中总氮(TN)的含量分别为0.86~2.34,1.63~4.75和0.26~2.53mg/L,夏季湖水中的总氮含量明显高于其他季节,说明东平湖中的N主要来源于面源污染。湖水中总磷含量的均值约为0.05mg/L,且不同季节间没有显著差异。综合营养指数评价结果表明,东平湖水体总体上处于中营养状态。大安山码头和腊山码头附近水体营养水平略高于其他区域,这与两个码头附近均有大片网箱养殖区和接纳较多生活污水有关。东平湖水体中春季、夏季和秋季的氮磷比分别为10.3~78、19~46和10.2~35,即总氮浓度均超过总磷浓度7倍以上,表明该湖属于磷营养限制性湖泊。

Distribution of Nitrogen and Phosphorus in Water and Eutrophication Assessment of Dongping Lake

Distribution of nitrogen and phosphorus in water of Dongping Lake were measured.Eutrophic status of the Lake was also assessed by integrated index.Results showed that concentration of total nitrogen ranged from 0.86 to 2.34,1.63 to 4.75 and 0.26 to 2.53mg/L for spring,summer and autumn respectively.Higher TN concentration in summer than that in autumn indicated that non-point pollution played an important role for TN in the Lake.No significant differences could be found for total phosphorus concentrations in the Lake among different seasons,with average concentration of 0.05mg/L.Result of integrated index indicated that the Lake was under the moderate eutrophication status.Ratio of nitrogen and phosphorus were higher than 7,indicating the phosphorus was the limited factor for eutrophication of the Lake.