太湖梅梁湾水源地示范区水质改善初探

WATER QUALITY IMPROVEMENT BASED ON THE PHYSIC-ECOLOGICAL ENCLOSURE MEASUREMENT IN MEILIANG BAY,LAKE TAIHU

基于改善环境、恢复生态系统的思路，在太湖梅梁湾水源地实施了旨在恢复水生植物的环境改善和生态修复工程。通过2003年8月开展的本底调查及2003年9月～2004年11月的水质监测资料，对太湖梅梁湾水源地水质改善示范区水质的时空变化趋势和质量状况进行了研究与评价。结果表明，工程实施前示范区内各点位的透明度、总氮、氨氮、总磷、叶绿素a等指标均超标，水质为Ⅳ-Ⅴ类，表现为富营养化水平；各项工程措施实施后水质有了明显改善，溶解氧明显升高，全年较2003年8月份升高34％，夏季较2003年8月也升高了17％，10个点透明度平均由0．29m提高到0．35m，增加了21％，强化净化区较外围区提高0．05m。但是，上述水质改善仅是生态工程物理效应的结果，由于水生植物尚未恢复，因此，有些指标的改善并不明显，如叶绿素等。但在可以预见的将来，在水生植物得到恢复后，其水质改善的趋势将更加明显。

The spatial temporal distribution of water quality was assessed based on the data from December in 2003 to November in 2004 obtained in Meiliang Bay drinking water purification demonstration enclosure in Lake Taihu. The background values of main water quality indexes including transparency, total nitrogen, ammonia nitrogen, total phosphorus, chlorophyll a, exceed environmental quality standards for surface water of type three and the demonstration zone belongs to eutrophication. Water quality of demonstration zone was improved obviously after the implement action of technical measures. Mean values of dissolved oxygen during the period from December of 2003 to November of 2004 increased 34%, in contrast to the background value in August of 2003. Transparency improved from 0. 29 to 0. 35 m, with 21%increase.