Planation Surface Extraction and its Geological Significance Based on DEM Data in Lancang County,Yunnan Province
The Lancang County is located in the western Yunnan region,where is the convergence of several tectonic plates,and the tectonic deformation is strong and the tectonic evolution is complex.In order to quantitatively analyze the deformation and evolution results of neotectonic movement in this county,ArcGIS software was used to obtain and analyze different geomorphic factors on the DEM data of this county,and the planation surface of Lancang County was obtained.The results show that more than 80％of the area in Lancang County is between 1 000～3 500 m above sea level,which belongs to the middle altitude area.The proportion of slope area is 52.82％,and the proportion of steep slope area is 36.82％.The proportion of small rolling mountains is 70.47％,the proportion of medium rolling mountains is 17.54％,and the proportion of hills is 10.38％.According to geomorphic parameters such as planation surface elevation,surface slope and topographic relief,the plane range with slope lower than 15°and topographic relief less than 500 m at the elevation of planation surface is determined,and four grade planation surfaces are identified and obtained.The formation time of first grade planation surface to fourth grade planation surface becomes later and the elevation decreases in turn.They are 1 856 m,1 626 m,1 301 m and 1 125 m respectively.The first and second grade planation planes were heavily modified by late tectonic processes and their remaining areas were small,and they were obviously affected by large strike-slip fault zones along the northwest direction,mainly distributed in the central and northeastern parts of the country.The third and fourth grade planation planes were mainly controlled by secondary faults,mainly distributed in the southwest of Lancang County.
NETL
NSTL
万方数据
