Analysis Of Geomorphological Features Of The Tibetan Plateau Based On SRTM-DEM

Geomorphology is one of the most predominant components of physical geographical environment. On the one hand geomorphology's forms and features have deep influences on the distribution and changes of ecological and environmental factors; on the other hand it even decides the pattern and degree of natural resource utilization. DEM is a digitized map that contains plentiful information about geomorphology, so it is the basis to analysis geomorphological structure. In recent years with the development of Remote Sensing, Geographical Information System and computer technology, many progresses have been made on DEM acquisition, conservation, management, application and so on.The Tibetan Plateau is regarded as 'the roof of the world'and 'the global third pole', with mean elevation more than 4000m, there were plenty of dynamic state information about the uplift and evolution of the Tibetan Plateau recorded in the varied geomorphology phenomenon. Therefore, the study on the features of geomorphology by DEM is essential and of great significance to the further research on the Tibetan Plateau.Based on SRTM-DEM with 90 resolutions, we extracted a series of geomorphological factors, such as slope, aspect, relief amplitude, and then we analyzed the features of landform on the Tibetan Plateau. Moreover we further divided the macroscopic types of geomorphology. Furthermore we extracted the distribution region of Periglacial Geomorphology on the Tibetan Plateau which made a reference to some studies on permafrost and snow line made by former researchers. Based on these analyses mentioned above, the conclusions can be drawn as follows:1. In analysis on relief amplitude, we using mean change point method to calculate the best statistical units. Based on SRTM-DEM with 90 resolutions, the best statistical units is 1.1664km~2 on the Tibetan Plateau.2. Geomorphological map specifications of China (1:1,000,000) is made as reference to study area, we divided the elevation into four types on the Tibetan Plateau: low, medial, high, higher. High elevation is the largest in area, the second is higher elevation, and the third is medial elevation, the last is low elevation. Moreover, the value of variance coefficient of elevation on the edge of the Tibetan Plateau is larger than that of the inside of the plateau.3. The area ratio with slope is less than 25°account for 79.90%, the area ratio with slope is more than 35°is 5.69%, and area ratio with slope between 25°—35°is 14.41%.4. Combined with geomorphological map specifications of China (1:1,000,000) and the relief amplitude, we divided the geomorphology into seven types on the Tibetan Plateau: plane, mesa, hills, low relief amplitude mountain, medial amplitude mountain, high amplitude mountain, and higher amplitude mountain.5. The value of SOA in Qaidam Basin is higher than other regions; it reflects the intensity of aeolian erosion.6. There is a higher positive correlation among slope, relief amplitude and the earth's surface incision.7. Based on relief amplitude and elevation, we divided the macroscopic geomorphology into twenty-seven types on the Tibetan Plateau.8. The area ratio of Periglacial Geomorphology is 52.46% on the Tibetan Plateau. It distributed on hills and low amplitude mountain with high or higher elevation.