应用地理信息系统对江宁县钉螺孳生地环境特征的分析

目的　探讨江宁县钉螺孳生地的环境特征。方法　在 Arc View8.1软件支持下 ,建立江宁县钉螺孳生地分布的地理信息系统 ,并利用其方位分析及图层叠加分析钉螺孳生地的空间方位及土壤类型特征。结果　通过建立 2 0 0 0年江宁县钉螺孳生地分布地理信息系统 ,可见江宁县钉螺分布呈聚集性 ;在此基础上 ,空间方位分析显示江宁县山区钉螺孳生地有 78.95 %分布在朝东及朝南等阳光充足的地区 ;进一步通过空间叠加发现 ,江宁县江滩钉螺孳生地的土壤类型主要为灰潮土及水稻土 ,且螺密度以灰潮土 >水稻土 ;虽然山区钉螺孳生地土壤类型较多 ,但还是以紫色土、水稻土及黄棕壤土为主 ,且螺密度以石灰岩土 >紫色土 >黄棕壤土 >水稻土 ,但差异无显著性 (P >0 .0 5 )。同时进一步分析发现 ,在土质沙粘、微碱性、有机质含量丰富的土壤中钉螺密度较大 ,酸性土壤中的钉螺密度则较小。结论　江宁县钉螺在东向或南向阳光充足、土质较粘、土壤偏碱且有机质含量较高的地区较多

Analysis on the environmental features for the distribution of oncomelenia snails in Jiangning county by the geographic information system

Objective To explore the environmental features for the distribution of oncomelenia snails in Jiangning county. Methods The GIS for the distribution of oncomelenia snails was established using the ArcView8.1, and the spatial aspect analysis and overlay analysis were used to explore spatial aspects and soil type of the snail habitats. Results The GIS of snail distribution demonstrated that the oncomelenia snails in Jiangning county in 2000 were grouped in certain areas. Further spatial aspect analysis showed that 78.95% snail habitats in the eastern and southern sunlight-rich part of mountainous areas in Jiangning county. And the overlay analysis revealed that the soil types of the snail habitats in marshland were mainly gray damp soil and paddy soil, and the density of snails in gray damp soils was higher than that in paddy soils. Although the soil types for the habitats in mountain varied, the majority of them belonged to purple soil, paddy soil and light brown loam respectively. The density of snails habitats of mountain decreased gradually from limestone soil, purple soil and light brown loam to paddy soils. Further analysis showed that the density of alive snails habitats, which were in the soil with clay texture, light alkality and more organic substance, was higher than that habitats in the acid soils. Conclusions The snail of Jiangning county habitats more in the areas with eastern and southern aspect, and in the soil types with light alkality, more organic substance and clay texture.