Geomorphic evolution processes of the relict landscape and deep-incised valleys along the Red River fault zone, Yunnan Province, China

Abstract:

Based on DEM analysis and field observations, the study reveals the form of topographic characteristics of the Red River region, Yunnan Province, China, which is in response to southeastward growth of the Tibetan Plateau. Knickpoints in the valleys along the Red River fault are objectively extracted, and an upper low-relief segment separated by the knickpoints is identified, and is corresponding to the relict landscape. Continuous Davisian landform-evolution processes and propagation of the topographic steady state along the fault demonstrate that the relict landscape should originally be a continuous surface. Moreover, as the distribution pattern of the knickpoints varies along the fault from northwest to southeast, the pattern is further examined to distinguish the climatic and tectonic influences. The study provides morpholoical evidences for the episodic Plateau uplift, and also help to understand the processes of the southeastward extension of the Plateau.