利用遥感图像对湖沼型血吸虫病疫区洲滩植被的聚类分析

Classification study on the marshland in endemic areas of Schistosoma Japonicum using satellite TM image data

目的 利用卫星专题制图仪 (thematicmapper ,TM)遥感图像对江西恒湖茶叶港湖沼型血吸虫病疫区洲滩植被进行聚类分析。方法 通过主成分分析确定用于聚类分析的TM3、TM4和TM5等 3个波段遥感数据 ,然后在遥感图像处理软件支持下对卫星TM图像进行假彩色合成及聚类分析 ,最后通过现场勘察确定不同类别的地物属性 ,并在研究现场进行螺情调查。结果 通过聚类分析和实地勘察 ,在研究现场的遥感图像上共划分出 3个地表类别 ,在各种植被中 ,占据绝对优势的苔草为茶叶港洲滩钉螺的主要孳生地。根据 2 0 0 0年春季的查螺结果 ,苔草生长区域的活螺密度和感染螺密度分别为 2 5 1 0 11m2 和 0 0 0 6 9 0 11m2 ,钉螺感染率为 0 2 8%。结论 遥感遥测技术有助于钉螺分布规律的研究 ,在血吸虫病及其他与生态有关疾病的流行病学研究中有着良好的应用前景。

Objective To create a land cover map of the marshland region of Schistosoma Japonicum using satellite TM data from Chayegang,Jiangxi Province. Methods Satellite data of three TM bands,namely TM3,TM4 and TM5,were selected to be used in classification study with Principal Components Analysis. Then TM satellite images were applied to false color composite and unsupervised classification with computer software to manage the TM data. Finally the resulting clusters were identified by undertaking site visits and a systematic sampling snail survey was also carried out in the study area in April,2000. Results Three land cover classes were generated,including class 1,the carex zone that is both the dominant vegetation and main snail habitats of the study area. Based on the snail survey in the spring of 2000,the live snail density and infectious snail density of the carex zone were 2.51/0.11 m 2 and 0.006 9/0.11 m 2,respectively. The infection rate of the snail was 0.28%. No snail was found in land cover class 3,the mixed vegetation,because the altitude of this area is either above 17 m or under 14 m and therefore the vegetation in this area is unsuitable for snails to survive. Conclusion Remote sensing can contribute the study on the distribution of snail habitats and become a promising epidemiological study method for schistosomiasis and other ecological diseases.