Abstract: Objective　To understand the distribution of Oncomelania hupensis snails and changes of water levels in Gaoyou sections of the Li Canal following the operation of the eastern route project of the South-to-North Water Diversion Project. Methods　The Oncomelania snails were monitored in the river banks and water bodies of Gaoyou sections of the Li Canal by means of systematic sampling combined with environmental sampling as well as collection of the floaters from 2014 to 2019, and the water levels were collected in Gaoyou sections of the Li Canal at the typical hydrological year before the operation of the eastern route project of the South-to-North Water Diversion Project and during the period between 2016 and 2019. Results　A total area of 235.42 hm2 were investigated and a total of 75.8 kg floaters were collected in Gaoyou sections of the Li Canal from 2014 to 2019; however, no snails were found. The water level in Gaoyou sections of the Li Canal was predominantly high in the flood season and low in the dry season before the operation of the eastern route project of the South-to-North Water Diversion Project, and the water level was elevated in the dry season and relatively low in the flood season after the operation of the project. Conclusion　Following the operation of the eastern route project of the South-to-North Water Diversion Project, the original river bank that is characterized by “land in winter and water in summer” has changed in Gaoyou sections of the Li Canal, which is not favorable for snail breeding.

Key words: Schistosomiasis, Oncomelania hupensis, Water level, Eastern route project of the South-to-North Water Diversion

摘要： 目的　了解南水北调东线工程通水运行后里运河高邮段钉螺分布及水位变化。方法　2014—2019年，采用系统抽样结合环境抽查法和打捞水体漂浮物观察法，分别对里运河高邮段河岸和水体进行钉螺监测；收集、分析南水北调东线工程运行前典型水文年份以及2016—2019年里运河高邮段水位变化情况。结果　2014—2019年，里运河高邮段累计开展钉螺调查235.42 hm2、打捞漂浮物75.8 kg，均未发现钉螺。南水北调东线工程运行前，里运河高邮段水位多为汛期较高、枯水期较低，运行后呈枯水期水位抬高、汛期相对较低的状态。结论　南水北调东线工程运行后，里运河高邮段改变了河岸环境原有的 “冬陆夏水” 状态，因此不利于钉螺孳生。

关键词: 血吸虫病, 钉螺, 水位, 南水北调东线工程, 里运河, 高邮市