[Study on influence of Three Gorges Project construction on Oncomelania growth condition in Chongqing section].

ABSTRACT

OBJECTIVE: To understand the effects of the change of climate, vegetation, flooding led by the construction of Three Gorges Project to the growth of Oncomelania snail. METHODS: The spatial analysis function of ArcGIS combined with meteorological data, 150 000 and the 110 000 digital elevation model were employed to analyzed the climate, flooding and other conditions of the reservoir area, and the field survey was used to investigated the vegetation in this area. RESULTS: The flood time, climate precipitation, sunshine duration, vegetation types and coverage of Three Gorges reservior area can meet the growth needs of Oncomelania snail. However, the characteristic of water impounding winter and disembogueing in summer were not agreed with the life circle of Oncomelania snail. CONCLUSIONS: The environment of flooding in winter and drought in summer in the Three Gorges reservior areas is not suitable for the growth of Oncomelania snail. If the transfusion of snais from other endemic areas can be prevented, the area can be avoid to become snail area.