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目的 了解 1998年洪水对扬州市江滩钉螺分布的影响和钉螺孳生地分布模型的实用价值。方法 采用现场人工调查和钉螺孳生地分布模型相结合的方法 ,按周晓农报道的模型在 ER-DAS软件上分别进行卫星遥感图象的叠加、校正、提取 ,用红色在图上标出钉螺的可疑孳生环境 ,并与地面调查结果进行核对验证。结果 1998年洪水后 ,江滩钉螺面积增加了 2 7.2 0 % ,2 5个抽样可疑钉螺孳生地洪水后钉螺面积增加了 6 1.48% ,洪水前 (1998年 )和洪水后 (1999、2 0 0 0年 )钉螺密度分别为 0 .945只 /框、1.2 78只 /框和 1.2 89只 /框 ,钉螺孳生地分布模型预测的钉螺可疑孳生地范围与洪水后两年春季查出钉螺分布范围总符合率为 88.0 0 % ,其中 30× 10 4m2 以上环境的符合率为90 .0 0 % ,10× 10 4～ 30× 10 4m2 环境的符合率为 10 0 % ,10× 10 4m2 以下环境的符合率为 75 .0 0 %。结论 1998年洪水后 ,扬州市钉螺明显扩散 ,钉螺孳生地分布模型对快速筛选钉螺可疑孳生地范围和确定钉螺孳生高危地带有重要意义。
Objective To understand the effect of flood in 1998 on the distribution of Oncomelania snail in Yangtan City and the practical value of distribution model of Oncomelania spp. Methods The method of on-the-spot manual survey and snail breeding site distribution was used to superimpose, calibrate and extract satellite remote sensing images on ER-DAS software according to the model reported by Zhou Xiaonong. Breeding environment, and with the ground survey results for verification. Results After the flood in 1998, the area of Oncomelania roseate was increased by 7.220%. The area of Oncomelania snail increased by 648% after flood of 25 samples of suspected snail breeding. Before the flood (1998) and after the flood (1999,200 0 years), the snail density was 0. 945 / box, 1.2 78 / box and 1.2 89 / box respectively. The range of suspicious breeding grounds for snail and the distribution of snail found in the spring two years after the flood The coincidence rate was 88.0%. The coincidence rate of the environment above 30 × 10 4m 2 was 90.0%, the coincidence rate of 10 × 10 4 ~ 30 × 10 4m 2 environment was 10%, and the environment below 10 × 10 4m 2 was consistent Rate was 75.0%. Conclusion After the 1998 floods, the distribution of snails in Yangzhou City and the distribution pattern of snail breeding areas are of great significance for the rapid screening of suspicious breeding places and the identification of high-risk areas for snail breeding.