Table 1.

Predicted impact of the Three Gorges Dam on the distribution of Oncomelania snails and transmission of S. japonicum

Segment of Yangtze River	Water level rising		Water level decreasing		Oncomelania snails	S. japonicum	Refs.
	Height (m)	Months	Height (m)	Months
Hubei (Jianghan Plain)	0.06–1.5	Jan – May	1.8–2.4	Nov, Dec	New habitats for Oncomelania snails would appear.	The probability of humans and livestock becoming infected would increase.	[17, 20, 23, 24]
Hunan (Dongting Lake)	0.06–1.5	Jan – May	1.6–2.6	Nov, Dec	The distribution of snails would not be significantly affected, however, the reproduction of snails would be effectively curbed.	The probability of humans and livestock becoming infected would increase and schistosomiasis epidemics would worsen.	[17, 20, 23, 25]
Jiangxi (Poyang Lake)	0.11–0.90	Jan – Mar	0.07–0.13	Dec	The reproduction and distribution of snails would be unaffected or the density of snails would increase, or the density of snails would decrease in the autumn.	The epidemiology of schistosomiasis would be very limitedly affected.	[17, 20, 23, 58, 59]
Anhui	0.14–0.76	Jan – Apr	0.06–1.26	Oct – Dec	The distribution of snails would not be significantly affected, however, some new habitats for snails would appear.	The probability of humans and livestock becoming infected would increase.	[17, 20, 24, 27, 60–62]
Jiangsu	0.15–0.40	Feb – Apr	0.32–0.75	Oct, Nov	The distribution of snails would be not affected and the density of snails would decrease.	The incidences of schistosome infections in people and livestock would increase.	[17, 20, 25, 27, 58]