三峡建坝对江汉平原血吸虫病疫区环境的影响研究

STUDY ON ENVIRONMENT IMPACT IN ENDEMIC AREA OF SCHISTOSOMIASIS I N JIANGHAN PLAIN FOLLOWING THE THREE GORGES DAM PROJECT

目的 对三峡建坝后可能对江汉平原地区血吸虫病传播产生影响的长江水位、地下水位、降雨量、蒸发量等环境因素进行调查并分析其影响程度。方法 收集三峡建坝前后长江不同典型水文年的逐月水位及螺情和病情资料 ;设立观测点观测地下水位、降雨量和蒸发量 ,并将有关环境因素与螺情和病情进行统计学检验和相关回归分析。结果 三峡建坝后 ,在 2～ 3月份长江水位将上升1.2 3～ 1.5 1m ;在 10月份将下降 1.88～ 2 .43 m ,这种长江水位升、降的变化 ,将对江汉平原沿江地下水位的侧向补给产生直接的影响。其波及范围 ,汛期最远达 15 km ,枯水季节最远达 7km。在沿长江 2 5个流行县、市中距长江 15 km范围内的疫区人口、钉螺面积和病人数分别占全省的 5 9.8%、6 1.1%和 6 3.7%。结论 三峡建坝后长江水位的变化对钉螺孳生环境将产生直接的影响。地下水位、降雨量、蒸发量。

Objectives To investigate and an alysis the environment factors, such as water level of the Yangze River, riparia n water table, annual rainfall and yearly evaporation, that might potentially af fe ct schistosomiasis transmission in Jianghan Plain after the Three Gorges Dam pro ject. Methods Data on typical water lever of th e Yangtze River pre and post Three Gorges Dam project and the snail distribut ion and schistosomiasis prevalence were collected by means of field surveys and obs ervation. Meanwhile, observation site was set up to record riparian water table, rainfall and evaporation. All information were analyzed with statistics method. Results The water level of the Yangtze River w ill rise 1.23～1.51 m in February and March and drop 1.88～2.43 m in October aft er the Three Gorges Dam project. The up and down on the water level of the Ya ng tze River will affect riparian water table directly. The range of the water tabl e to be affected will be within 15 km along the Yangtze River in flood season an d 7 km in dry season. The population, the snail habitats area and the number of patient in 25 cities along the Yangtze River are 59.8%,61.1% and 63.7% in wh ole province, respectively. Conclusions The cha nge of the water level of the Yangtze River will affect the snail habitats direc tly in this area. In addition, riparian wat er table, rainfall, evaporation are related with schistosomiasis transmission in this area.