高山地区钉螺分布的空间特征研究

Spatial characteristic of distribution of Oncomelania hupensis in mountainous regions

目的分析山区钉螺分布的空间特征。方法建立四川省普格县钉螺分布的地理信息系统（GIS），用空间自相关分析和空间扫描统计量法研究山区钉螺分布的空间特征。结果普格县钉螺分布存在空间自相关，其有螺框出现率的全局Moran’s I指数为0．095（P〈0．05），局部空间自相关分析显示有28个钉螺孳生地的局部空间关联指数（LIsA）值有统计学意义（P〈0．05），这些环境又可细分为高一高、低一低、低一高和高一低四种空间关联模式。空间扫描统计量法共探测出24个钉螺孳生地聚集区，其中有14个高值聚集区，10个低值聚集区（P〈0．05），与局部空间自相关的结果较为吻合。结论普格县山区钉螺分布存在空间自相关，钉螺孳生地在空间上呈一定的聚集性，同时存在空间分布的异质性，利用这一规律可以更好地控制钉螺。

Objective To analyze the spatial characteristic on the distribution of Oncomelania hupensis in mountainous regions. Methods Based on the geographic database of snail distribution in Puge county, Sichuan province, spatial autocorrelation analysis and spatial scan statistics were applied to analyze the spatial characteristic of snail distribution. Results With regard to the rate of frame with snails, the global Moran＇ s I indicator was 0.095 （P〈0.05） , which indicated the spatial autocorrelation of snail distribution in Puge county. Data from the local spatial autocorrelation analysis showed that there were 28 snail habitats with statistically significant differences on local indicators of spatial autocorrelation （LISA）value（P〈0.05）, among which existed high-high, low-low, low-high and high-low four types of correlation model. The Spatial Scan Statistics had in total identified 24 snail habitat clusters （P〈O.05） , including 14 high rate clusters and 10 low rate clusters, and the result was similar to that of LISA analysis. Conclusion There were spatial autocorrelation and spatial aggregation of snail distribution in mountainous regions, meanwhile spatial heterogeneity of snail distribution also existed. This law could be explored for better control of snails.