中文摘要：

于2012年7月至2013年7月采集固城湖及其出入湖河道水样,测定水体理化特征指标,探讨固城湖水质时空分布差异,并根据2001—2012年水质监测数据,利用PWQTrend 2010软件分析近年来固城湖及官溪河的水质变化趋势。结果表明：固城湖大湖区、港口河和漆桥河水质较好,丰水期处于轻度富营养化状态;小湖区、养殖区排污口、官溪河和胥河受纳污染负荷较大,丰水期处于中度富营养状态,而枯水期大、小湖区及出入湖河道都处于中营养状态。目前水质主要受氮磷污染的影响,主要污染源为水产养殖;2001—2012年官溪河和小湖区总体上属于Ⅲ~Ⅳ类水质,大湖区则属于Ⅲ类水质,受高淳社会经济发展和环境保护措施的影响,官溪河总氮、总磷浓度呈显著下降趋势,小湖区总氮浓度,大湖区总氮、总磷浓度都呈显著上升趋势,因此合理规划养殖业发展规模和模式,减少各类污染源排放量,是保证固城湖可持续发展的必要措施。

英文摘要：

Water samples were collected from Gucheng Lake and its inlets and outlets during the period between July 2012 and July 2013 for analysis of physic-chemical properties（ including nutrient contents,BOD5,suspended organic matter）to explore spatio-temporal variation of the water quality of the lake and based on the monitoring data accumulated during the year of 2001-2012,developing tendency of the water quality in the lake in recent years was also analyzed with the aid of Software PWQTrend 2010. Results show that the water in the main area of the lake,Gangkou River and Qiqiao River was quite good in quality and got slightly eutrophied during the wet season,but the water in arms of the lake,in waste discharge outlet of aquatic breeding zones,and in Guanxi River and Xuhe River was quite high in pollution load and got moderately eutrophied during the wet season. However,during the dry season,the water in the whole area（ the main area,arms,inlets and outlets of the lake） was moderately entrophied. Currently nitrogen and phosphorus are the main water pollutants in this study area,and come mainly from aquaculture. During the year of 2001- 2012,the water in Guanxi River and the arms of the lake fell generally into Grade Ⅲ / Ⅳof the ＂National Standard for Surface Water Quality for Drinking Water＂,and the water in the main lake area did into Grade Ⅲ in quality. Total nitrogen（ TN） and total phosphorus（ TP）in the water of Guanxi River decreased significantly from 2001 to 2012,but TN in the arms of the lake and TN and TP in the main lake area increased significantly as affected by the economic development in Gaochun District,and some environmental protection measures. Therefore,rationally programming development scale and mode of the aquaculture in the lake and reducing waste discharge from various pollution sources are essential measures for sustainable development of Gucheng Lake.