应用ETM^+遥感图像监测山区钉螺分布

APPLICATION OF LANDSAT7-ETM^+ IMAGE IN SURVEILLANCE OF SNAIL DISTRIBUTION IN MOUNTAIN AREAS

目的 分析ETM+ 遥感卫星图像中植被指数与山区钉螺分布之间的关系 ,为进一步建立钉螺分布的遥感预测模型提供理论依据。 方法 现场测量江宁县 2 0 0 0年各钉螺孳生地经纬度 ,在ERDAS 8.5软件支持下将ETM+ 卫星图像中的 3、4波段合成为江宁县植被指数图层 ,利用ArcView8.0软件制作钉螺分布Vector图层 ,提取各钉螺孳生地植被指数 ;用相关性分析法和多元逐步回归分析法研究图层中植被指数与钉螺分布间的关系。 结果 山区各钉螺孳生地活螺框出现率与该钉螺孳生地缓冲区内最小NDVI值及平均NDVI值呈正相关 (r分别为 0 .3 5 6、0 .3 44,P <0 .0 5 ) ;钉螺密度与各钉螺孳生地缓冲区内最大、最小及平均NDVI值呈正相关 (r分别为 0 .418、0 .43 3、0 .44 8,P <0 .0 1)。回归分析结果显示 ,山区各钉螺孳生地活螺框出现率与平均NDVI(Nmean)有关 [Y1=160 .62Nmean(R2 =0 .67,P <0 .0 1) ] ;山区钉螺密度与平均NDVI值有关 [Y2 =9.65Nmean(R2 =0 .5 3 ,P <0 .0 1) ]。 结论 ETM + 遥感卫星图像可以监测山区钉螺的分布。

Objective To analyze the relationship between NDVI of Landsat7-ETM + image and the snail distribution in mountain areas,to provide the theoretic foundation for establishing the remote sensing forecast model for snail habitats distribution. Methods The NDVI was extracted from ETM + image by vector chart of the snail distribution using ArcView8.1 and ERDAS 8.5 software: The relationship between NDVI and the snail distribution was investigated using bivariate correlations and stepwise linear regression. Results The incidence of pixel with the alive snail on mountain correlated positively with the minimum NDVI,mean NDVI ( r= 0.356 ,0.344,P <0.05).Otherwise the snail density on mountain correlated positively with the minimum NDVI,mean NDVI,maximum NDVI( r=0.418,0.433,0.448,P <0.01). Regression results showed that the incidence of pixel with the alive snail on mountain correlated with the mean NDVI \[Y 1 =160.62Nmean( R 2 =0.67,P <0.01)\];the snail density on mountain correlated with the mean NDVI\[Y 2 =9.65 Nmean( R 2 =0.53,P <0.01)\]. Conclusion The ETM + satellite images can be used to survey the distribution of snail on mountain.