基于GF-1和Landsat 8影像的新疆东天山昌吉地区岩性识别

Lithology Identification in Changji Area,Eastern Tianshan,Xinjiang Using GF-1 and Landsat 8 Data

新疆东天山地区气候恶劣,基岩裸露,遥感解译效果良好。已有1∶20万地质图中岩性的圈定较为笼统,出露较小的岩体、岩脉多有遗漏,缺乏高分辨率遥感技术的应用。以新疆东天山昌吉地区为研究区,基于GF-1和Landsat 8两种影像,运用彩色空间变换(IHS)、Gram-Schmidt等方法进行空间分辨率融合,并对影像进行假彩色合成(FCC)、主成分分析(PCA)、最小噪声分离变换(MNF)等岩性信息增强处理,结合DEM数据构建的三维影像图和已有地质记录,建立影像解译标志,进行细致的岩性单元识别和地质填图。通过野外验证、岩石样品薄片鉴定和反射光谱特征分析对解译结果进行修正,形成了研究区1∶5万遥感解译地质图。结果表明:在基岩露头较好的新疆东天山昌吉地区,融合多源遥感数据可识别1∶20万地质图遗漏的岩性单元,对岩性界线进行修正,提高地质填图的工作效率,为后续地质调查、地质找矿等工作提供依据。

The Eastern Tianshan regions of Xinjiang were characterized by severe climate and exposed bedrock.The lithological boundaries were not accurate enough in the existing 1∶200000 geological map,and the applica⁃tion of high-resolution remote sensing technology was lacked.GF-1 and Landsat 8 satellite images were used for lithology identification and geological mapping in Changji Area,Eastern Tianshan,Xinjiang.Image process⁃ing technology such as IHS and Gram-Schmidt were executed to obtain high spatial resolution images.And the image processing process was based on image enhancement using False Color Composite(FCC),Principal Component Analysis(PCA)and Minimun Noise Fraction(MNF).Image interpretation markers were estab⁃lished by the combination of 3D image constructed from DEM data and available geological records.Additional⁃ly,an updated 1∶50000 lithological map was generated for study area by fieldwork verification,sample thin sec⁃tion identification and reflectance spectrum characteristic analysis.The results showed that,in Changji area with good outcrop of bedrock,the integrated application of multi-source remote sensing data could identify the litho⁃logical units which were missed in the 1∶200000 geological map and corrected the lithological boundaries.It im⁃proved the efficiency of geological mapping and guided the follow-up geological survey and geological prospect⁃ing.