The Physiognomy Morphological Characters and the Origin of the Area in the First Turn of Yangtze River Based on DEM

By using digital elevation model(DEM) on the macro landform parameters,river geomorphology,geologic structure background of the Tuoding- Sanjiangkou section of Jinsha River.Comprehensive analysis the system,we find that there is obvious geomorphologhical differences in the local geographic area,and the edge area shows the characteristics of high grade and relief.Slope and topography of the central region is relatively slow,and the study area first increased and then decreased.The branch of the lower section has the characteristics of the larger longitudinal slope,and the development degree of the tributaries on the east side of the branch of Jingsha River is less than that of the west.The characteristics of geomorphological parameters on both sides of the branch in study area indicate the rapid uplift and subsidence movement of structural zones since late Cenozoic,and caused the difference of development degree in the two sections which is separated by Shigu area.Quantitative analysis geomorphic parameters of the upper reaches of the Jinsha River,that will provide important scientific evidence and perspectives to the geomorphic history,paleoenvironmental evolution in the study area.