三峡库区重庆段钉螺孳生条件

三峡工程的修建使得长江水生环境发生了变化,同时水库的阶段性蓄、放水使得阶段性淹没的江洲滩增加,更加有利于挺、浮水植物的繁殖,从而可能形成适合日本血吸虫(Schistosoma japonicum)的惟一中间宿主———钉螺(Oncomelania hupensis)的生长环境。本文在钉螺生活习性的基础上,结合数字高程模型(DEM)和相关的气象资料以及水库的蓄放水规律,从气候、淹没时间、植被、水库的蓄放水时间等角度对三峡库区钉螺孽生条件进行了分析。从气候上看,阶段性淹没区能够满足钉螺生长的需要;然而,水库冬季蓄水、夏季放水的周期与钉螺生长需求并不完全相同,尤其是冬季的高水位对钉螺生长十分不利。因此,水库的修建并不一定会造成钉螺的孽生和血吸虫的流行。

The Study of Three Gorges Project on Oncomelania hupensis of Chongqing Area

The construction of Three Gorges Project results in water current slow down and enlarges the area of mudflat which is along the Yangtze River and its main tributaries submerges periodically.The changed environment might favor the survival and dispersal of Oncomelania hupensis who is the host of Schistosoma japonicum.In this paper,we predicted the possible influence of climate data,vegetation and the periodically flooded on O.hupensis survival and dispersal in submerged mudflat based on the life history of O.hupensis using 1∶ 50 000 and the 1∶ 10 000 DEM of the study area.The climatic condition and flood period in the study area is possible to meet their requirement.However,the life history of O.hupensis is not matched with the time schedule of the Three Gorges Reservoir impounding water in winter and disembogue water in summer.Therefore,the construction of the project would not increase the possibility of O.hupensis survival and dispersal in the study area.