學術活動

How the morphology of Earth’s surface evolves with time is controlled by the interactions of tectonic, climate and surface processes over time and space. Therefore, determining whether a given landscape is in a steady or disequilibrium state, and how the landscape will change to reach equilibrium, will help us understand the processes underlying landscape evolution. However, as it is challenging to measure erosion rates throughout an entire landscape, it is not easy to assess how the landscape will change with time.
To overcome this challenge, we developed a measure of river basin disequilibrium, χ, extracted from current geometry of the river network to examine the dynamic state of river basins. χ is a proxy of steady-state channel elevation, so it can be used to assess if a divide is static. If there is a cross-divide difference in χ, the divide is not at steady state and will move from low χ to high χ to approach equilibrium. However, as χ is integrated from base level, any changes in uplift rate or erodibility along channels will perturb χ values at channel heads that could lead to incorrect predictions. Therefore, other geomorphic metrics such as hillslope gradient and channel steepness at channel heads are also incorporated to perform the χ analysis.

(Eidgenössische Technische Hochschule Zürich, ETH Department of Earth Sciences )瑞士理工學院地球科學系博士
現任：國立台灣大學地理環境資源學系 博士後研究員