根据江苏西部主要湖泊水环境质量实测数据,采用综合营养状态指数[TLI(∑)]法对其富营养化程度进行综合评价,结果表明,目前江苏西部大部分湖泊处于富营养化状态.其中,白马湖富营养程度最低[TLI(∑)为45.16],处于中营养；玄武湖营养程度最高(61.93),属于中度富营养.洪泽湖和邵伯湖的水质为劣V类,其他湖泊除白马湖外水质均处于Ⅳ～V类之间.从近年江苏西部湖泊的水质变化看,只有骆马湖和玄武湖水质呈现转好的趋势,ρ(TN)和ρ(TP)有所下降.大部分西部湖泊水质呈恶化趋势,洪泽湖、高邮湖和固城湖ρ(TN)不断上升,邵伯湖和石臼湖ρ(TP)也不断上升.不同湖泊水环境变化的成因有所不同,洪泽湖水质受上游河流污染以及农业面源污染影响较大.由于江苏西部湖泊的地理、水文和环境条件的差异,不同湖泊存在不同的营养盐基准.相对于非过水性湖泊,洪泽湖等过水性湖泊的氮磷营养物基准相对较高.%Based on water quality monitoring data of major lakes in west Jiangsu Province,the eutrophic levels of the lakes were evaluated using a comprehensive trophic state index. The results showed that most of the lakes in west Jiangsu Province were in a eutrophic state,of which the lowest eutrophic level was mesotrophication (45. 16) in Lake Baima.and the highest eutrophic level was middle eutrophication (61.93) in Lake Xuanwu. The water qualities of Lake Shaobo and Lake Hongze were worse than the Chinese National Standard V. With the exception of Lake Baima,the quality of all the other lakes were between the Standards IV and V.Regarding the changes of water quality of the lakes in west Jiangsu Province in recent years, only the water qualities of Lake Luoma and Lake Xuanwu were improving-the total nitrogen and the total phosphorus mass concentrations were decreasing. The water qualities of most of the lakes were worsening-the total nitrogen mass concentrations increased consistently in Lake Hongze, Lake Gaoyou and Lake Gucheng.and the total phosphorus mass concentrations increased consistently in Lake Shaobo and Lake Shijiu. There were different causes of the changes in water environment in the various lakes. The water quality of Lake Hongze is mainly affected by upper river pollution and agricultural non-point pollution. There are different nutrient criteria in the various lakes due to their differences in geographical, hydrological and environmental conditions. Relative to a high hydrodynamic retention lake, thenutrient criteria of nitrogen and phosphorus in a low hydrodynamic retention lake is relatively high,such as in Lake Hongze.
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