Current situation of good water quality reservoirs in hilly region of south-east China: protection practices of Tianmuhu Reservoir

Abstract

东南丘陵山区是我国水库分布最为集中的区域之一,这些水库在保障区域供水安全方面具有极其重要的作用,应该优先保护.然而,水库水环境保护正面临丘陵山区开发强度持续增加,开发方式和空间布局不合理,氮、磷污染及富营养化趋势严峻,缺乏完善监测和管理体系等众多问题.本文以2000年以来天目湖水库保护实践过程为例,从库体水环境治理、流域污染物削减和综合管理3个方面介绍天目湖沙河水库保护的措施和成效,在此基础上提出良好湖库优先保护的建议:建立具有部门协调能力的水库管理机构,实行基于湖库水生态目标的水质目标管理,治理丘陵山区茶果园的面源污染,注重流域生态系统整体的恢复,禁止上游水源涵养区和临湖地带的开发,划定生态保护红线,明确禁止和限制的开发类型与规模,加强湖库及流域的监测和预警,开展必要的水库水体治理工程,并针对性地制定湖库管理条例.天目湖十几年的保护实践中有效地解决了流域开发与水库水质保护之间的矛盾,使天目湖水质由快速恶化转为稳步好转,为东南丘陵山区经济发展过程中水库的环境保护探索了一条道路.;A lot of reservoirs are distributed in hilly region in south-east China.These reservoirs are vitally important in providing water resources and should be priorly protected.However,much problem exists in protecting reservoir water quality in the hilly region, including increased development intensity of land resource,unreasonable development approaches and spatial arrangements, serious nitrogen and phosphorus pollution and eutrophication,and lack of advanced monitoring and management systems,etc.Taking Tianmuhu reservoirs as an example,this paper introduced the measures taken to protect Shahe Reservoir (one of Tianmuhu reservoirs) since 2000 and their effect in reservoir treatment,watershed pollutant reduction and integrated watershed management.Based on these analyses,suggestions are made to protect the reservoirs or lakes with good water quality.These suggestions include establishing reservoir management organizations with good departmental coordination,carrying out water quality target management based on lake and reservoir water ecological objectives,controlling non-point source pollution from tea orchards in the hilly area,focusing on restoration of watershed ecological systems,prohibiting land exploitation in upstream hilly area and area close to the lake,determining the red line of ecological protection,defining clearly the prohibit and restrict development types and dimensions, strengthening the monitoring and pre-warning systems of lake,reservoir and watershed,carrying out necessary reservoir treatment, and developing management regulations of lake and reservoir accordingly.After more than ten-year protection practices of Tianmuhu Reservoir,the conflict between watershed development of land resource and reservoir water quality protection was moderated.The lake water quality is changing from rapid deterioration to steady improvement,which provides an effective way for reservoir water environment protection in hilly region of south-east China.