Linear structure extraction and quantitative analysis of multi-source remote sensing information in West Junggar Basin

The western Junggar region, which is sandwiched between the nearly EW-trending Irtys fault and the Tianshan strikeslip fault system, has experienced long and complicated history of intracontinental tectonic deformation since the Late Paleozoic. The length, direction and spatial distribution of tectonic lineaments can not only reflect the strength and style of structural deformation but also indicate the mode of stress action. In this paper, the western Junggar region in northwest Xinjiang was selected as the research area. The spatial distribution and spectral information of fault structures in multi-source data such as ASTER and Landsat were displayed by color composite, principal component analysis(PCA), band ratio and Sobel filtering. The linear structures in the study area were extracted by combining Canny edge detection and visual interpretation. The principle and method of geostatistics were used to quantitatively analyze the extracted linear structures. The results show that the strike of the main faults determined by the optimum orientation of length in the study area is N50°-60°E, which represents the orientation of the distribution of the regional first-order structure, namely the Dalabut fault. The strike of the secondary faults determined by the optimum orientation of the number of linear structures is 80°-90° (in nearly EW direction), which represents the orientation of the regional third-order structures. The linear structures between the above two structures, namely moderate structures in number and length, represent the orientation of the regional secondary structure. The regional distribution of linear structures reveals the structural system composition and deformation characteristics of the western Junggar region under the action of the principal compressive stress in the NS direction. Therefore, the quantitative analysis of linear structures extracted from multi-source remote sensing image is of great significance for the determination of regional fault tectonic system.