日本琵琶湖的治理历程、效果与经验

以琵琶湖富营养化综合治理历程为主线,对琵琶湖30余年的治理过程、资金投入、治理措施、成功经验与成果进行了梳理. 截至2006年,琵琶湖综合整治历时35a,总投资约2.86×1012日元(约相当于1800×108元人民币),参照我国GB 3838—2002《地表水环境质量标准》,目前琵琶湖北湖水质维持在Ⅰ类水平,南湖由Ⅲ～Ⅳ类水恢复到I～Ⅱ类水质. 琵琶湖的治理分为2个阶段:第一阶段为1972—1997年,历时25a,这一阶段在琵琶湖水资源有效利用及防洪防灾上取得很大成就,但水质与环境仍在恶化； 1999年至今为第二阶段,主要目标是水质保护、水源涵养及自然环境与景观保护,目前琵琶湖富营养化已得到有效控制. 琵琶湖采取的综合治理措施主要包括依法治湖、中长期综合治理规划、流域污染源系统控制、自动监测系统及专门研究机构建立以及公众参与等5个方面. 主要治理经验包括:①严格控制氮、磷污染源,管网及大型污水处理设施建设着眼于未来长远规划,污水处理深度除磷脱氮技术的普及是污染源系统控制的关键；②大力提高森林覆盖率以减少面源污染的产生,改善水源涵养及流域生境；③切实做到有法必依、执法必严,实现依法治湖；④高度重视环境教育及公众参与；⑤积极推动各科研机构对环境问题的研究. 

Experience and Inspiration of Eutrophication Control for the Lake Biwa, Japan

Taken comprehensive eutrophication management course of Lake Biwa as the main issue, we teased out its management course over thirty years including economic investment, control measures and successful experience and achievements. The comprehensive treatment in Lake Biwa lasted for thirty-five years by 2006, costing about 2.86trillion yen (￥ 180billion). With reference to Environmental Quality Standards for Surface Water (GB 3838-2002) of China, the current water quality of the north basin of Lake Biwa falls into GradeⅠ, while the south basin has changed from Ⅲ-Ⅳ to Ⅰ-Ⅱ. The management course of Lake Biwa can be divided into two stages. The first stage was from 1972to 1997, lasting twenty-five years. During this period, great achievements were made on the efficient use of water resources, as well as flood and disaster prevention. However, the water quality and environment became worse. The second stage was from 1999to now. The main goals of this stage are water quality protection, water source conservation and natural environment and landscape protection. So far, eutrophication has been effectively controlled in the lake. Comprehensive managements mainly include five aspects:ruling the lake by law, medium-and long-term comprehensive management plans, systematic control of watershed pollution sources, automatic monitoring systems and establishment of specialized research institutions and public participation. Successful experiences could be take as references as follows:First, nitrogen and phosphorus pollution sources should be strictly controlled. Construction of urban sewage pipeline network and large centralized sewage treatment facilities needs long-term plans for the future. Popularization of advanced technology on phosphorus and nitrogen removal for the sewage treatment is the key point. Second, raise the forest coverage during urbanization to reduce the generation of non-point source pollution and improve water conservation and watershed ecosystem. Third, lake environment protection governance must be strictly carried out on the law. Fourth, pay high attention to education on environment and public participation. Finally, promote research on environmental issues of lakes by scientific institutions.