利用地理信息系统数据库分析钉螺空间区域的分布

Analysis for Spatial Distribution of Oncomelania Snail in China's Mainland by Geographic Information System (GIS) Database

目的 利用地理信息系统（ＧＩＳ）数据库分析中国大陆钉螺的空间区域分布。方法 收集中国九省３４ 个种群钉螺等位基因实验所得的种群遗传变异资料以及钉螺易感性实验资料，建立数据库。以世界数字地图为背景，在ＡｒｃＶｉｅｗ ３．０ ａ 软件上与钉螺的遗传变异和易感性数据库相联。采用ＡｒｃＶｉｅｗ 空间分析和ＧＩＳ重叠分析功能进行区域划分。收集１９９５ 年ＡＶＨＲＲＮＤＶＩ卫星图像组合成流行季节的卫星图像，并重叠各种群钉螺的杂合指数、多态位点百分率和血吸虫感染率分布图，进行图像分类。结果 空间分析结果，将钉螺遗传杂合性指数、多态位点百分率和钉螺感染率的分布图，划分成西部和东部二大区域，各区域内有各种类型。三层分布图与ＡＶＨＲＲＮＤＶＩ卫星图像重叠分析后，显示出西部四川、西部云南、中部江湖洲滩和东南部沿海４ 个明显不同的区域。结论 首次运用ＧＩＳ分析种群遗传学资料，佐证了中国大陆钉螺种群结构为分裂亚群结构，并可区分出多个亚种的理论。

Objective To analyze spatial distribution of Oncomelania snail populations in China's Mainland by geographic information system (GIS) database. Methods Genetic variation experiment data and experimental data of susceptibility of 34 snail populations were collected from nine provinces in China, to set up a database. A world digital map was linked with the database in a software ArcView Release 3.0 a to be used to divide zones with ArcView spatial analyze function and GIS overlaying function. AVHRR NDVI satellite images were collected to form a new one for prevalent season, which were overlaid with distribution maps of heterozygous indices of snail populations, polymorphic locus percentage and infection rates of snail population with schistosome for classifying the images. Results Spatial analysis showed that distribution maps of genetic heterozygous indices of snail, percentage of polymophic loci and infection rate of snail can be divided into two large zones, i.e., east zone and west zone, both with varied pictures. Analysis for overlaying three stratum distribution map with AVHRR NDVI satellite image showed four distinctly different spatial zones, including west Sichuan zone, west Yunnan zone, middle zone of river, lake and marshland, and southeast coastal zone. Conclusion It is the first time using GIS to analyze data of Oncomelania population genetics and confirmed the population structure of Oncomelania snails presented discrete sub population model, which supports the theory of sub species of Oncomelania spp. Exited in China's Mainland.