摘要
对瑞典的梅拉伦、哈马伦、韦特恩和维纳恩等四个大湖水质进行的监测已差不多有40年了。对湖泊的物理化学参数、浮游生物和底栖无脊椎动物进行了定期评估。对湖泊的水文和沉积条件、大型植物、鱼类、原始有机物产率、细菌和附生藻类进行了定期调查。人类活动(包括工业活动)的影响表现在湖中有机质、养分、金属和持久性有机化合物过量增加。从60年代末开始,对这些湖泊汇水区内所有市政污水处理厂都进行了更新改造,使其达到了最高技术标准(包括磷的化学沉淀处理),因而污水处理厂的磷排放减少了90%～95%。此外还对工业企业作出了规定,要求它们减少有害物质的排放。本文讨论了对湖泊采取治污措施后湖泊的变化情况以及各种指标达到的水平。这些研究有助于制定全国性湖泊监测计划。另外,通过大湖监测取得的成果有助于制定国家水质标准,包括物理、化学和生物学标准。
The large lakes of Sweden, Mlaren, Hjlmaren, Vttern and Vnern, have been subjected to water-quality monitoring for almost four decades. Physicochemical variables, plankton and benthic invertebrates have been regularly assessed. Hydrological and sediment conditions, macrophytes, fish, primary production, bacteria and attached algae have been periodically investigated. The human impact, including industrial activities, was reflected in excessive amounts of organic matter, nutrients, metals and persistent organic compounds. From the late 1960s all municipal sewage works in the catchments of the lakes were upgraded to the highest technical standard, including chemical precipitation of phosphorus, and phosphorus discharge from the sewage works was thereby reduced by 90–95%. In addition, industries were obliged to restrict discharge of harmful substances. The reactions of the lakes to the remedial measures are discussed as well as the value of various indicators. The studies were instrumental in designing a national lake monitoring program. Additionally, results from large lake monitoring have contributed to the establishment of national water-quality criteria including, physical, chemical, and biological indicators.
