一种改良的基于RS/GIS技术的鄱阳湖区钉螺滋生地获取方法研究
An Improved RS/GIS Method to Obtain Snail Habitats in the Poyang Lake Region

运用遥感影像处理软件对鄱阳湖区丰水期与枯水期影像进行监督分类获取水体范围,两者相减获取“冬陆夏水”区;在“冬陆夏水”区内计算归一化植被指数(NDVI)并提取植被覆盖区;提取鄱阳湖区13～ 18 m的高程范围;将提取的区域与查螺数据进行空间叠加对比分析.在“冬陆夏水”区的13 ～18 m高程范围内,归一化植被指数(NDVI)大于0.17的区域为适宜钉螺孳生的环境;经检验,计算结果得出的钉螺孳生地栅格级准确率达到70.91；.研究表明,鄱阳湖区“冬陆夏水”范围和植被覆盖范围广大,预测模型中增加适宜钉螺孳生的高程信息将提高计算结果的精确度.
Water body area was extracted from the RS images in flood season and dry season of the Poyang Lake region by Supervised Classification.The area of “water in summer and land in winter” was determined by subtracting the waters in the two classified images.Secondly,the vegetation-covered areas was derived from the subtracted areas using Normalized Difference Vegetation Index (NDVI).Then,the elevation of 13 to 18 m regions was extracted from the Digital Elevation Model of the Poyang Lake region.Finally,the above computed areas were overlapped with the field surveyed snail data,and the areas suitable for snail habitat were the Intersected areas with elevation between 13 to 18 m and NDVI>0.17 in the area of “water in summer and land in winter”.Results indicate that inclusion of elevation data can tremendously improve the accuracy of modeling results