塔里木盆地北缘绿洲盐渍化地地物光谱特征分析

以新疆塔里木盆地北缘渭干河—库车河三角洲绿洲为研究区,采用CI700便携式野外光谱仪,通过大量的野外调查以及实地测点,分析了该绿洲盐渍化地区的几种典型地物(盐渍化地、细沙地、沙丘、棉花地等以及柽柳、骆驼刺、芦苇等)的光谱特性及其变化规律,尤其是对盐渍化地和盐生植被的光谱曲线的差异做出了分析,并根据实际情况,采用移动平均法进行了噪声去除,分析实测光谱数据噪声特征。同时利用导数光谱技术清除植被环境背景影响。并且也利用归一化的方法基本消除了不同程度的盐渍地光谱和同一采样点不同时期的盐渍地光谱由于采样时的光照条件、气候条件等所引起的光谱差异。在对实测光谱数据进行处理的基础上,并利用ENVI软件建立了小型的渭干河—库车河三角洲绿洲主要地物的光谱库,该库可服务于渭—库绿洲的地物调查、植被调查、植被分类和环境监测等遥感应用。

Spectral Properties Analysis of Salinity Soils with Ground Objects in the North of Tarim Basin

The spectral features and changing rules of saline-alkaline ground,silver sand ground,dune,cotton ground as well as Tamarix chinensis,Alhagi sparsifolia,Phragmites australis,Halostachys caspica were studied with CI 700 portable spectrum analyzer by field investigation and determination on the spot taking the delta oasis of Weigan and Kuqa Rivers located in the North of Tarim Basin as the research area.The difference of the spectrum curves of saline-alkaline ground and halophytes was discussed.According to the actual conditions,the noise characteristic of the spectrum data was analysed by the moving mean method for denoising.The derivative spectrum technology was applied to remove the influences of environmental background on the vegetation.In addition,the normalization process was used to eliminate the spectrum differences among different saline-alkaline soils and the same sampling spot at different stages resulting from climatic conditions.The spectrum knowledge base for the delta oasis of Weigan and Kuqa Rivers was established with ENVI software,which can service for ground object investigation,vegetation survey,vegetation classification,and environmental monitoring in the delta oasis of Weigan and Kuqa Rivers by the applications of remote sensing.