Geomorphic expressions of collisional tectonics in the Qilian Shan, north eastern Tibetan Plateau

The Qilian Shan, north eastern Tibetan Plateau, is an area of active deformation caused by convergence in the India-Eurasia collision zone. Geomorphic indices capture the landscape response to competition between tectonics and climate, reflecting the spatial distribution of erosion. We use geomorphic indices (hypsometric integral (HI), normalised channel steepness (ksn), elevation-relief ratio (ZR) and surface roughness (SR)) to identify areas of active deformation and erosion, highlight landscape variations and we interpret the results for potential tectonic and climatic drivers. High HI (> 0.15), ksn (> 100) and low ZR (< 2) occur in the hanging wall of thrust faults, consistent with active uplift of these structures. Relatively high HI (> 0.15) and ksn (> 100) values in the eastern region are attributed to thrust parallel rivers in this region excavating wide valleys between the faults. The east-west precipitation variation across the Qilian Shan (>500 mm/yr to