主成分融合在干旱区盐渍地信息提取中的应用研究

土壤盐渍化严重威胁着干旱区绿洲的稳定与可持续发展,因此借助遥感手段快速提取盐渍地信息并掌握其空间分布有着重要的现实意义。本文以渭干河-库车河三角洲绿洲为例,探讨了基于主成分融合的干旱区盐渍地信息的提取方法。由于Landsat-7 ETM+的全色波段与多光谱波段有相同的太阳高度角和其他环境条件,影像获取时间一致,两种不同分辨率的数据可以不经配准而实现高精度融合。首先,对2001年的遥感影像数据(ETM影像)进行几何校正;再利用主成分融合技术,将多波段的ETM+影像与对应的全色波段影像进行主成分融合,在此基础上进行盐渍地信息的提取。实验表明,该方法的结果分类精度较高,与实地调查结果基本相符,是监测干旱区盐渍地变化的有效手段。结果表明:盐渍地主要分布在绿洲的和沙漠之间的交错带,盐渍地的分布在绿洲内部呈条形状分布,而在绿洲外部呈片状分布,且绿洲外部重度盐渍地交错分布在中轻度盐渍地中。研究结果对于干旱区绿洲盐渍地的合理开发和可持续发展有着重要现实意义。

The Application of Principal Component Fusion in the Extraction of Saline Soil Information in Arid Areas

Soil salinization has severely threatened the inner stability and the sustainable development of oasis in arid areas,so extracting the saline soil information rapidly based on remote sensing and mastering its spatial distribution are of important practical significance. In this article,taking the delta oasis of Weigan and Kuqa rivers as the example,utilizing ETM image data,the approach of effective remote-sensing information extraction for saline soil in arid areas based on principal component fusion was discussed. The Landsat-7 ETM Panchromatic band was taken simultaneously with muhispectral bands using the same sensor system.The solar illumination and other environmental conditions were identical;They were received at the same time.The two data sets,therefore,could achieve the best fusion result without coregistration. In consideration of the geometric effect,the ETM images for the year of 2001 were revised. Then the principal component analysis was performed by fusion of multiple spectral bands of the ETM images with their panchromatic images,and based on which,the saline soil information was extracted. Experiment showed that with high precision of classification,the result of the method accorded well with that of the field investigation,and that it could be an effective method for monitoring saline soils in arid area. The results indicated that saline soil mainly distributed in the ecotone between the oasis and the desert,and it assumed the strip shape distribution in the oasis interior,while assumes the laminated distribution outside the oasis,and severe saline soil interlocks in milddle and slight saline soil outside the oasis.The results of study are of great practical significance to the reasonable development and the sustainable development of saline soils of the oasis in arid area.