摘要
钉螺的分布与其孳生地环境的自然因素密切相关，并具有一定的空间特征。在建立洞庭湖区江滩钉螺分布地理信息系统的基础上，运用GIS空间分析技术，对钉螺孳生地的环境状况作了多因子分析，发现洞庭湖区江滩钉螺孳生地植被类型主要为芦苇和莎草类，孳生地的土壤类型主要为潴育性水稻土；孳生地土壤为pH值处于5．5～7．5的弱酸性环境，有机质含量处于2％～3％；80％孳生地的植被标化指数在0．100～0．375之间、土壤湿度在0．202～0．507之间、近水源距离为10～230之间。并且标化植被指数、莎草类植被类型与钉螺密度成正相关，而pH值、有机质含量均成负相关。同时，钉螺密度的分布也具有一定的特征：（1）在空间上呈集聚模式；（2）空间自相关性比较强，相关程度受离群值的影响；（3）变异函数呈指数模型，并存在空间方向性。
The survival of Oncomcelania Snails relates closely to the environmental factors of habitats, and Oncomcelania Snails＇ distribution has some spatial characterizes. Based on the GIS of the Oncomcelania Snails＇ distribution in Dongting Lake, the authors analyze the environmental condition of the Oncomcelania Snails＇ habitates comprehensively by the spatial analyzing technology. The results are showed as follows： firstly, the predominant vegetation of Oncomcelania Snails habitat is reed and sedgy. Secondly, the predominant soil type of the Oncomcelania Snails breeding area is gleyic paddy soils, which is a weak acidity environment with pH value of 5.5 ~ 7.5, and its organic content is in 2% -3%. Thirdly, the normalized difference vegetation index （NDVI） of 80 percent of the Oncomcelania Snails breeding area is 0. 100% -0.375% and its soil humidity is 0. 202 - 0.507, and its distance to the water is 10 -230 meters. The results from the correlation analyses between the environmental factors and the Oncomcelania Snails＇ distribution indicate that there are positive correlations between the density of Oncomcelania Snails and the normalized difference vegetation index （NDVI）/type of sedgy, and negative correlations between the density of Oncomcelania Snails and the PH value/organic content of the soil. In the end, from analyzing the Oncomcelania Snails＇ spatial distribution in marshlands of Dongting Lake, some conclusions about Oncomcelania Snails＇ density are drawn as follows： （1）there is a spatial clustering model. （2）there is an intensely spatial auto-correlation, which is influenced by exceptional value. （3）the variation function is exponential and has a spatial directivity.
出处
《自然灾害学报》
CSCD
北大核心
2008年第4期19-27,共9页
Journal of Natural Disasters
基金
该研究得到湖南省自然科学基金项目(07JJ6073)
湖南省高等学校青年骨干教师和湖南省省级重点学科自然地理等的资助
关键词
遥感
地理信息系统
钉螺
空间分析
remote sensing
geographic information system
Oncomcelania Snails
spatial analysis
