A new approach for landform classification based on geomorphic entity objects: a case study on the Tibetan Plateau

Landform classification studies are prerequisites for recognizing regional geomorphic patterns and are urgently needed to explore the process of landform development and evolution. Taking the Tibetan Plateau as the study area, this paper proposes new geomorphologic classification methods and indicators, such as slope-cost distance and mountain undulation, considering the global topographic features and the integrity of geomorphologic objects. On this basis, the classification of geomorphic types on the Tibetan Plateau was completed. The results show that: (1) The proportion of plains within the mountainous Tibetan Plateau has reached 25%, with the ratio of the mountain and plain areas close to 3:1, and the mountain types are dominated by low-relief mountains and middle-relief mountains. (2) The spatial distribution of the plains is characterized by high fragmentation and low spatial aggregation, with an overall dispersed distribution "from inside to outside". (3) The mountains form an overall topographic skeleton of "three horizontal and one vertical" and the global landform pattern of the Tibetan Plateau is complex and diverse. The outcomes can provide a reference for digital terrain analysis and landform classification-related studies.