九龙江入海河口水质主要化学要素含量年际变化趋势和季节变化特征研究

文章根据2011—2020年九龙江河口入海监测断面表层水连续10年的水质监测数据得出：（1）2011—2020年九龙江河口入海监测断面表层水水质年际变化特征为近10年来九龙江入海河口水质得到了明显改善，尤其是2016—2020年高锰酸盐指数、氨氮、总磷、石油类浓度呈现持续下降的趋势，下降幅度较大，表明“十三五”期间九龙江流域水质得到了明显改善，但是总氮仍然超标严重。（2）2020年九龙江河口入海监测断面水质的季节变化特征为：高锰酸盐指数、氨氮、总氮、无机氮、总磷夏季含量相对较低，冬季含量相对较高。化学需氧量的季节变化特征为冬季含量相对较低，秋季含量相对较高。而石油类的季节变化特征为秋季含量相对较低，春季和冬季含量相对较高。（3）2011—2020年九龙江与闽江、晋江、龙江、木兰溪等福建省内其他主要入海河流河口入海监测断面水质对比分析得出，闽江、晋江河口入海监测断面水质较好，龙江、木兰溪河口入海监测断面水质较差，九龙江河口入海监测断面水质一般。研究结果以期为九龙江水环境规划与管理提供参考。

Characters of Annual Variation and Seasonal Variation of Main Chemical Elements in Water Quality of Jiulong River Estuary

The research results showed that the water quality of Jiulong River Estuary has been improved in the past 10 years, especially the permanganate index, ammonia nitrogen, total phosphorus and petroleum showed a continuous decline from 2016 to 2020, indicating that the water quality of Jiulong River Basin has been significantly improved during the Thirteenth Five-Year Plan period, however, the total nitrogen exceeded the standard seriously, based on the survey data of surface water of Jiulong River estuary for 10 years from 2011 to 2020. The characteristics of seasonal variation are as follows: In 2020, permanganate index, ammonia nitrogen, total nitrogen, inorganic nitrogen and total phosphorus are relatively low in summer and high in winter; and the chemical oxygen demand is relatively low in winter and high in autumn; and the petroleum is relatively low in autumn and high in spring and winter.Based on the comparative analysis of the water quality of monitoring sections of Jiulong River and other major rivers entering the sea in Fujian Province, such as Minjiang River, Jinjiang River, Longjiang River and Mulan River from 2011 to 2020, the water quality of Minjiang River estuary and Jinjiang River estuary is relatively good, and Longjiang River estuary and Mulan River estuary are relatively poor, and Jiulong River estuary is average. It will provides reference for environmental planning and management of Jiulong River.