基于格网数据驱动的螺情信息空间分析与研究

Spatial analysis of Oncomelania snail information based on grid data-driven

目的探索湘江长沙段洲滩螺情与水源距离、土壤湿度、植被分布、汛期平均水位的关系。方法应用基于格网数据驱动的GIS空间分析方法,结合洲滩标准化植被指数、土壤湿度,对2005-2009年湘江流域长沙段的螺情信息进行分析,并对汛期平均水位与螺情反复、洲滩钉螺密度的变化关系进行分析。结果 2005年甑皮州钉螺主要分布在距最近水源40～240m的范围内,60m处分布最多。钉螺密度与水位存在较明显的正相关性。2005年甑皮州标准化植被指数范围为0～0.982,土壤湿度范围为0～0.298,植被类型分布以杂草和莎草为主。基于水源基准线作出了年度螺情变化的洲滩螺情势图,可直观了解螺情发展情况。结论利用格网数据驱动的螺情信息空间分析方法,可以更准确地反映钉螺网格所在地的植被和土壤湿度状况以及洲滩钉螺的态势,从而及时掌握流行状况。即使在人工干预的情况下,水位变化仍然是导致螺情变化的重要因素。

Objective To explore the relationship between the Oncomelania snail situation and the distance to the water source, soil humidity, vegetation and water level in flood seasons in the islets of Changsha Section of the Xiang River. Methods Combined with the NDVI and soil humidity of islets, the GIS spatial analysis based on grid data-driven was used to analyze the snail situation in Changsha Section of the Xiang River from 2005 to 2009. The relationship between the snail density and the water level in blood seasons was analyzed. Results In 2005,the snails in Zengpi Islet were mainly distributed at the range of 40-240 m far away from the nearest water source, and the number at the spots with a distance of 60 m was the largest. There was an obvious positive correlation between the snail density and water level in flood seasons. The ranges of the Normalized Difference Vegetation Index and soil humidity of Zengpi Islet in 2005 were 0-0.982 and 0-0.298, respectively and the main vegetation in Changsha Section of the Xiang River were weed and sedge. The map of snail situation by year was drawn according to the standard water level, which reflected the snail situation intuitionistically. Conclusions By using spatial analysis based on grid data-driven, the situation of vegetation, soil humidity and snail accurately can be reflected, which can help us to understand the endemic situation timely. Even under the circumstance of human intervention, the water level in flood seasons is still an important factor influencing the change of snail situation.