| The formation of landforms is controlled by neotectonic movements,and the deformation of surface morphology is a response to tectonic activities.The Yunnan-Guizhou Plateau is situated in the southeastern piece of the Qinghai-Tibet Plateau,which is the elevate reaction zone of Plateau.Concentrating on the geomorphological highlights of the Yunnan-Guizhou Plateau is useful to get a handle on the attributes of provincial structural exercises,and is of extraordinary importance for understanding the reaction of the Yunnan-Guizhou Plateau to the inspire of the Qinghai-Tibet Plateau.Quantitatively extracting the surface morphology of landform parameters can evaluate the tectonic activity of the region;linear structure is the expression of tectonic activities such as fault folds on the surface,which provides an important reference for discriminating and analyzing tectonic characteristics;fluvial landforms are sensitive to neotectonic movements,and are the research structure.An important carrier of activities affecting the surface morphology.Based on this,taking the Wujiang River Basin on the north side of the Guizhou Plateau as the research unit,the lineaments of the Wujiang River Basin was extracted based on the Landsat 8 image,and the multi-geomorphic parameters of135 sub-basins of the Wujiang River were extracted by using digital elevation data(DEM).The parameters include the longitudinal section of the river,hypsometric Integral(HI),drainage basin asymmetry(AF),drainage basin shape index(BS)and the index of relative active tectonics(Iat).Statistical analysis of each index is carried out to quantify the degree of regional tectonic activity,and to explore the indicative significance of linear tectonic and geomorphic parameters to tectonic movement.The conclusions reached mainly include:(1)Comparing the water systems extracted by the five digital elevation models of ASTER,SRTM,NASADEM,AW3D30 and Tan DEM-X90,AW3D30 has the highest data extraction accuracy.Using AW3D30 data to extract the optimal catchment area of the Wujiang River Basin is 27 km~2.The landforms in the Wujiang River Basin have strong spatial heterogeneity,and the basin is dominated by steep slopes,which are mostly developed on both sides of the river valley;the surface undulations in the upper and lower reaches are higher than those in the middle reaches.(2)The linear structures in the Wujiang River Basin are dominated by short and medium lengths,with complex structures.The optimal orientations are NE?NEE and NNE,which is consistent with the distribution law of fault folds in the region.The linear structure controls the development of the water system in the basin,and the structure density indicates that the tectonic activity in the middle reaches is the strongest.(3)The development of the water system in the Wujiang River Basin is affected by the tectonic uplifting movement.The longitudinal profiles of the main tributaries are mainly linear fitting,and the rivers are mostly in their infancy;the Hack profiles are mostly upward convex curves,and the longitudinal profiles of the rivers are in the non-equilibrium section toward the equilibrium section.The initial evolutionary stage of development.The abnormal peak value of the standardized river length slope index value(SL/K)is often crossed by fault zones,indicating that this part of the river reach is affected by tectonic activities,and the longitudinal section of the local river reach is also affected by the lithology of the river bed,the inflow of tributaries,human activities and other factors.(4)The Wujiang River Basin is in the prime of its geomorphological evolution.Areas with relatively strong tectonic activity are concentrated in the right bank of the Yachi reach,both sides of the lower reaches of the Wujiang River,and some sub-basins in the upper reaches;areas with relatively weak tectonic activities are concentrated in the sub-basin between the Shuichi River and Ganlong River on the right bank of the middle and lower reaches.The spatial distribution of relative tectonic activity intensity is consistent with regional paleoseismic distribution and linear tectonic density distribution.Studies have shown that linear tectonic and geomorphic parameters can reflect regional tectonic activity to a certain extent,and the two are consistent in their performance.Various geomorphological parameters can better reflect the intensity of tectonic activity in the Wujiang River Basin from different angles,and the evolution of Wujiang river landforms is greatly affected by tectonic activity.The research results have certain instructive significance for further detailed tectonic activities in the Wujiang River Basin. |
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