关键词: 三峡库区宜昌段, 蚊类, 变动趋势

Abstract:

Objective To get an insight into the dynamics of mosquitoes in the process of the hydraulic cascade development in the Yichang section of the Three Gorges Area, providing important background information for medical assessment of the environment for large-scale water control project. Methods The data on mosquitoes in this area recorded since 1959 with those from 1971 to 2009 collected through investigation were studied and analyzed. The density of mosquitoes was surveyed with the labor-hour method. Results There was an overall downward trend in the density of mosquitoes in the Yichang section of the Three Gorges reservoir area in different periods with a higher density in barns than in houses. The mosquito density during 1971 to 1980 reached the highest value (239.0 per house/hour) compared with the density in the periods before and after the time. From 2001 to 2009, when the second and third stage construction of the Three Gorges Project was completed, the density fell to historic lows (75.2 per house/hour). There were great changes in the composition of mosquito species in both the barns and the houses, which was related to the alteration of the environment where mosquitoes bred, and explained the epidemic features of the vector-borne diseases. Conclusion Currently the density of mosquitoes in the Yichang section of the Three Gorges reservoir area has fallen to historic lows with no significant fluctuations seen in the incidence of the related diseases in the area. The hydropower projects do not show a significant impact on them.

Key words: Three Gorges area, Mosquito, Changing trend