乌梁素海遥感影像的水体提取方法与分析

乌梁素海地处干旱的内蒙古巴彦淖尔盟乌拉特前旗境内，因此水体及地物的光谱特征都具有干旱区草型湖泊的特性。本文选取2002年11月8日的ETM遥感图像数据，应用单波段阈值法、色度判别法、比率法、多波段组合运算法及多光谱分析法对水体进行提取，分别阐述了各种方法的优缺点，但其一考虑到水体提取的简单易行，因此采用多波段组合运算法；其二考虑到遥感信息机理以及各种地物的结构、组成和理化性质的差异，而导致不同的地物对电磁波的反射特征也各有不同，所以择取易与明水水体相混淆的芦苇、居民地、林地、山体阴影4种地物在TM1、TM2、TM3、TM4、TM5、TM7六波段的光谱特征值，应用多光谱混合分析法提取乌梁素海水体范围，从而避免了单—红外波段影像的不足。最后将多波段组合法与多光谱混合分析法进行比较，并阐述了二者的适用范围。

The Water Withdraws and Spectral Characteristic Analysis of Background Surface Features in Wuliangsu Lake

Wuliangsu lake lies in Wulate banner of Bayanur league of Inner Mongolia, so water and the spectral characteristics of surface features all have specific property of dry-land and grass-type lake. It chose ETM data in Nov 8th 2002 and used single band threshold value method, colority distinguish method, ratio analysis and spectral integrated analysis method to withdraw water area, further more explain the advantage and disadvantage respectively, but considering remote sensing information mechanism, the difference of surface features lead to the changes of reflectance, thus select the spectral characteristic value of reed, residential area, tree area, mountain shadow which is easy to confuse clean water at TM1,TM2,TM3,TM4,TM5,TM7, and use spectral integrated analysis method to withdraw Wuliangsuhai clean water to avoid the disadvantage of single band and complexity of other method.