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目的评价洪涝灾害后通江河道砼护坡控制钉螺效果。方法选择受长江洪涝灾害影响的通江河道及其流域作为研究现场,对通江河道砼护坡工程实施前后流域内河道、灌区及通江口外江滩进行钉螺消长的纵向观察,评价护坡工程控制钉螺效果;同时对河道内潮位变化、钉螺扩散、滩地淤积等影响因素进行观察研究。结果实施通江河道砼护坡3年,河道钉螺面积下降74.68%,有螺框出现率下降61.15%,活螺密度下降85.65%,钉螺感染率及感染性钉螺面积降至0。但其后钉螺面积则徘徊不下,有螺框出现率上升,并再次出现感染性钉螺;内陆灌区钉螺面积、有螺框出现率、活螺密度均呈缓慢波动上升趋势;河道内水体持续保持血吸虫感染性。影响因素研究表明:通江河道内潮位变幅大,月平均潮位差在3.45~5.57m;河道内由于工程原因和泥沙淤积,存在大量孳生钉螺的淤积滩地;汛期河道漂浮物平均携带钉螺18.10只/kg;通江口外存在大面积江滩钉螺,钉螺密度呈增长趋势;同时河道沿线涵闸均缺乏防螺措施。结论在水位未控制的通江河道单纯进行砼护坡不能防止钉螺扩散,也不能完全消除水体血吸虫感染性。建议此类通江河道应优先考虑控制水位,增加防螺措施,同时最大限度控制和杀灭通江口外江滩钉螺。
Objective To evaluate the effect of snail control by concrete slope protection after flood disaster. Methods Tungjiang River and its watershed affected by the flood and flood in the Yangtze River were selected as the research site. Longitudinal observation of the growth of Oncomelania hupensis in the river courses, irrigation areas and the outer estuary of the estuary of the Tongjiang River before and after the Tongjiang River revetment was carried out. Effect; at the same time changes in the tide level, snail spread, beach deposition and other factors were observed and studied. Results After 3 years of Tongjiang river slope revetment, the area of oncomelania snail decreased 74.68%, the occurrence rate of snail box decreased 61.15%, the live lobed density decreased 85.65%, the infection rate of snail and the area of infected snail decreased to 0. However, the area of snails afterwards was less than or equal to that of snails. The occurrence rate of snails was increased and the infective snails appeared again. The area of snails, the occurrence of snails and the density of live snails in the inland irrigation area showed a slowly rising trend. The water bodies in the river continued to maintain Schistosoma infectivity. The research on influencing factors shows that the tidal range of the Tongjiang River channel changes greatly and the monthly mean tidal range difference is between 3.45 and 5.57m. Due to the engineering reasons and sedimentation in the river channel, there are a large number of silted beaches where snails are breed. In the flood season, / kg; there is a large area of river beach snail on the estuary of Tongjiang River, and the density of snail is on the increase; at the same time, the sluices along the river channel lack the anti-snail measures. Conclusions Pure slope protection in the uncontrolled Tongjiang River can not prevent the spread of Oncomelania and can not completely eliminate the infection of Schistosoma japonicum. It is suggested that priority should be given to the control of water level in such thoroughfares to increase the anti-spiral measures and at the same time to control and kill the snail on the outer riverbank of Tongjiangkou to the maximum.